WO2016195279A1 - Ship - Google Patents

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Publication number
WO2016195279A1
WO2016195279A1 PCT/KR2016/005139 KR2016005139W WO2016195279A1 WO 2016195279 A1 WO2016195279 A1 WO 2016195279A1 KR 2016005139 W KR2016005139 W KR 2016005139W WO 2016195279 A1 WO2016195279 A1 WO 2016195279A1
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WO
WIPO (PCT)
Prior art keywords
compressor
gas
boil
heat exchanger
refrigerant
Prior art date
Application number
PCT/KR2016/005139
Other languages
French (fr)
Korean (ko)
Inventor
신현준
최동규
문영식
Original Assignee
대우조선해양 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020150135997A external-priority patent/KR101599404B1/en
Application filed by 대우조선해양 주식회사 filed Critical 대우조선해양 주식회사
Priority to RU2017145887A priority Critical patent/RU2715971C2/en
Priority to EP16803634.1A priority patent/EP3305649B1/en
Priority to JP2016556014A priority patent/JP6204609B2/en
Priority to PL16803634.1T priority patent/PL3305649T3/en
Priority to US15/579,571 priority patent/US10654553B2/en
Priority to CN201680046393.7A priority patent/CN107922037A/en
Priority to SG11201710007QA priority patent/SG11201710007QA/en
Publication of WO2016195279A1 publication Critical patent/WO2016195279A1/en
Priority to PH12017502178A priority patent/PH12017502178A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
    • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
    • F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
    • F02M21/0287—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers characterised by the transition from liquid to gaseous phase ; Injection in liquid phase; Cooling and low temperature storage
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B25/00—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby
    • B63B25/02—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods
    • B63B25/08—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid
    • B63B25/12—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed
    • B63B25/16—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed heat-insulated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H21/00—Use of propulsion power plant or units on vessels
    • B63H21/38—Apparatus or methods specially adapted for use on marine vessels, for handling power plant or unit liquids, e.g. lubricants, coolants, fuels or the like
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
    • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C6/00—Methods and apparatus for filling vessels not under pressure with liquefied or solidified gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C9/00—Methods or apparatus for discharging liquefied or solidified gases from vessels not under pressure
    • F17C9/02—Methods or apparatus for discharging liquefied or solidified gases from vessels not under pressure with change of state, e.g. vaporisation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/0002—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
    • F25J1/0022—Hydrocarbons, e.g. natural gas
    • F25J1/0025—Boil-off gases "BOG" from storages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
    • F25J1/0032—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration"
    • F25J1/0035—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by gas expansion with extraction of work
    • F25J1/0037—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by gas expansion with extraction of work of a return stream
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
    • F25J1/0032—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration"
    • F25J1/004—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by flash gas recovery
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0201—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using only internal refrigeration means, i.e. without external refrigeration
    • F25J1/0202—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using only internal refrigeration means, i.e. without external refrigeration in a quasi-closed internal refrigeration loop
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
    • F25J1/0229—Integration with a unit for using hydrocarbons, e.g. consuming hydrocarbons as feed stock
    • F25J1/023—Integration with a unit for using hydrocarbons, e.g. consuming hydrocarbons as feed stock for the combustion as fuels, i.e. integration with the fuel gas system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
    • F25J1/0275—Construction and layout of liquefaction equipments, e.g. valves, machines adapted for special use of the liquefaction unit, e.g. portable or transportable devices
    • F25J1/0277—Offshore use, e.g. during shipping
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
    • F25J1/0285—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings
    • F25J1/0288—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings using work extraction by mechanical coupling of compression and expansion of the refrigerant, so-called companders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
    • F25J1/0294—Multiple compressor casings/strings in parallel, e.g. split arrangement
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/30—Use of alternative fuels, e.g. biofuels

Definitions

  • the present invention relates to a ship, and more particularly, to a ship including a system for re-liquefying the remaining boil-off gas used as the fuel of the engine in the boil-off gas generated inside the storage tank.
  • Liquefied gas liquefied gas at low temperature has the advantage that the storage and transport efficiency can be improved because the volume is very small compared to the gas.
  • liquefied gas, including liquefied natural gas can remove or reduce air pollutants during the liquefaction process, it can be seen as an environmentally friendly fuel with less emissions of air pollutants during combustion.
  • Liquefied natural gas is a colorless and transparent liquid obtained by liquefying natural gas containing methane as a main component at about -162 °C, and has a volume of about 1/600 compared with natural gas. Therefore, when liquefied and transported natural gas can be transported very efficiently.
  • the liquefaction temperature of natural gas is a cryogenic temperature of -162 °C
  • liquefied natural gas is easily evaporated because it is sensitive to temperature changes.
  • the storage tank storing the liquefied natural gas is insulated.
  • the natural gas is continuously vaporized in the storage tank during the transport of the liquefied natural gas.
  • -Off Gas, BOG occurs.
  • BOG -Off Gas
  • Boil-off gas is a kind of loss and is an important problem in transportation efficiency.
  • the internal pressure of the tank may be excessively increased, and there is also a risk that the tank may be damaged. Accordingly, various methods for treating the boil-off gas generated in the storage tank have been studied.
  • a method of re-liquefying the boil-off gas to return to the storage tank, and returning the boil-off gas to the fuel of a ship engine The method used as an energy source of a consumer is used.
  • a refrigeration cycle using a separate refrigerant is used to re-liquefy the boil-off gas by exchanging the boil-off gas with the refrigerant, and a method of re-liquefying the boil-off gas itself as a refrigerant without a separate refrigerant.
  • PRS Partial Re-liquefaction System
  • DFDE is composed of four strokes and adopts the Otto Cycle, which injects natural gas with a relatively low pressure of 6.5 bar into the combustion air inlet and compresses the piston as it rises.
  • the ME-GI engine is composed of two strokes and employs a diesel cycle that directly injects high pressure natural gas near 300 bar into the combustion chamber near the top dead center of the piston. Recently, there is a growing interest in ME-GI engines with better fuel efficiency and propulsion efficiency.
  • a vessel comprising a liquefied gas storage tank, the first compressor capable of compressing at least a portion of the boil-off gas discharged from the storage tank; A second compressor for compressing another part of the boil-off gas discharged from the storage tank; A propelling compressor for compressing a part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A first heat exchanger configured to heat exchange the boil-off gas compressed by the propulsion compressor with the boil-off gas discharged from the storage tank; A refrigerant reducing device for expanding another part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger configured to cool the boil-off gas compressed by the propulsion compressor and heat-exchanged in the first heat exchanger by using the fluid expanded by the refrigerant reduction device as a refrigerant; An additional compressor for compressing the refrigerant having passed through the refrigerant reducing device and the second heat exchanger; And a
  • the propulsion compressor may compress only the boil-off gas compressed by the first compressor, and the refrigerant reducing device may expand only the boil-off gas compressed by the second compressor.
  • the additional compressor may compress the refrigerant passing through the second heat exchanger to be sent to the second compressor.
  • the additional compressor may compress the refrigerant passing through the second heat exchanger and send the refrigerant to the first compressor and the second compressor.
  • the propulsion compressor compresses a part of the boil-off gas compressed by the first compressor and the second compressor, and the refrigerant reducing device expands another part of the boil-off gas compressed by the first compressor and the second compressor. You can.
  • the boil-off gas sent to the second heat exchanger passes through the second heat exchanger firstly and is expanded by the refrigerant pressure reducing device, and then is sent to the second heat exchanger again, and is expanded by the refrigerant pressure reducing device and then the refrigerant pressure reducing device.
  • Fluid used as a refrigerant in the fluid is sent to the second heat exchanger before passing through the refrigerant pressure reduction device; And the boil-off gas cooled by the first heat exchanger after being compressed by the propulsion compressor.
  • the vessel further comprises a gas-liquid separator separating the partially reliquefied liquefied gas and the evaporated gas remaining in the gaseous state through the propulsion compressor, the first heat exchanger, the second heat exchanger, and the first decompression device. It may include, the liquefied gas separated by the gas-liquid separator is sent to the storage tank, the boil-off gas separated by the gas-liquid separator may be sent to the first heat exchanger.
  • a portion of the boil-off gas sent to the propulsion compressor may be branched upstream of the propulsion compressor and supplied to the fuel demand.
  • the vessel may form a closed loop refrigerant cycle in which boil-off gas circulates the second compressor, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor.
  • a vessel comprising a liquefied gas storage tank, comprising: a first compressor capable of compressing at least a portion of the boil-off gas discharged from the storage tank; A second compressor for compressing another part of the boil-off gas discharged from the storage tank; A propelling compressor for compressing a part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A refrigerant reducing device for expanding another part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger configured to cool the boil-off gas compressed by the propulsion compressor using the fluid expanded by the refrigerant reduction device as a refrigerant; An additional compressor for compressing the refrigerant having passed through the refrigerant reducing device and the second heat exchanger; And a first decompression device configured to expand the fluid cooled in the second heat exchanger after being compressed by the propulsion compressor, wherein the additional compressor is driven by power generated by the refriger
  • the ship boil-off gas treatment system including a storage tank for storing liquefied gas, a portion of the boil-off gas discharged from the storage tank by the first compressor A first supply line which is compressed and then sent to the fuel demand; A second supply line branched from the first supply line and compressing another portion of the boil-off gas discharged from the storage tank by a second compressor; A return line branched from the first supply line to further compress the compressed boil-off gas by means of a propulsion compressor and then reliquefy by passing through a first heat exchanger, a second heat exchanger, and a first pressure reducing device; A recirculation line passing through the second heat exchanger and the refrigerant pressure reducing device and sending the cooled boil-off gas back to the second heat exchanger for use as a refrigerant; And an additional compressor installed upstream of the second compressor to compress the boil-off gas, wherein the additional compressor is driven by a power produced by the refrigerant
  • the additional compressor may be installed on the second supply line.
  • the additional compressor may be installed on the recirculation line downstream of the refrigerant reducing device and the second heat exchanger.
  • the evaporative gas treatment system of the vessel may include a first additional line connecting between the refrigerant reducing device and the second heat exchanger downstream of the second heat exchanger and a second supply line upstream of the second compressor.
  • the boil-off gas treatment system of the vessel passes through the first additional line after the boil-off gas passes through the additional compressor, the second compressor, the second heat exchanger, the refrigerant pressure reducing device, and again the second heat exchanger. It is possible to form a closed loop refrigerant cycle, which is supplied to the additional compressor again.
  • the boil-off gas compressed by the first compressor and the boil-off gas compressed by the second compressor are combined to partially reliquefy along the return line, and the other part of the second heat exchanger along the recycle line; After passing through the refrigerant reducing device and the second heat exchanger again, the refrigerant may be discharged from the storage tank and joined with the fluid passing through the first heat exchanger, and the remaining part may be supplied to the fuel demand.
  • the boil-off gas compressed by the first compressor is partially liquefied along the return line, the other part is supplied to the fuel demand, and the boil-off gas compressed by the second compressor is along the recycle line.
  • the second heat exchanger After passing through the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger, the second heat exchanger may be discharged from the storage tank and joined with the fluid passing through the first heat exchanger.
  • the evaporation gas treatment system of the vessel forms a closed loop refrigerant cycle in which the evaporation gas circulates the second compressor, the second heat exchanger, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor. can do.
  • the vessel's boil-off gas treatment system includes: a second additional line branched from a recirculation line downstream of the additional compressor and connected to the first supply line upstream of the first compressor; A third additional line branched from a first supply line downstream of the first compressor and connected to a recirculation line upstream of the refrigerant reducing device and the second heat exchanger; And a fourth additional line branched from a second supply line downstream of the second compressor and connected to the return line upstream of the propulsion compressor.
  • a closed loop refrigerant cycle can be formed that passes through and is fed back to the second compressor.
  • the boil-off gas treatment system of the vessel after the boil-off gas is compressed by the first compressor, is supplied to the second heat exchanger along the third additional line and the recirculation line, the refrigerant pressure reducing device, again the second Through a heat exchanger and the further compressor, a closed loop refrigerant cycle may be formed which is fed back to the first compressor along the second additional line.
  • one of the branched boil-off gas is compressed by the first compressor, the other flow is 2 is compressed by the compressor, and the boil-off gas compressed by the first compressor is further compressed by the propulsion compressor, and then re-liquefied to return to the storage tank, and the boil-off gas compressed by the second compressor is used for the refrigerant cycle.
  • a method is provided wherein a fluid that circulates to cool the boil-off gas compressed by the first compressor, and the fluid that circulates the refrigerant cycle is supplied to the second compressor after being compressed by an additional compressor.
  • the present invention can increase the reliquefaction efficiency and the amount of reliquefaction since the boil-off gas is decompressed after additional cooling by the second heat exchanger.
  • it is economical to re-liquefy most or all of the remaining boil-off gas without using a refrigeration cycle using a separate refrigerant.
  • the re-liquefaction efficiency and the amount of reliquefaction are increased by using the spare compressor that is already installed, it contributes to securing the space on board and further reduces the cost of installing the compressor.
  • the boil-off gas compressed by the main compressor as well as the boil-off gas compressed by the main compressor can be used as the refrigerant in the second heat exchanger, thereby increasing the flow rate of the boil-off gas used as the refrigerant in the second heat exchanger.
  • the reliquefaction efficiency and the amount of reliquefaction can be further increased.
  • the mass of the fluid used as the refrigerant in the second heat exchanger after being compressed by the second compressor becomes larger, it is possible to increase the reliquefaction efficiency and the amount of reliquefaction in the second heat exchanger. Can utilize the power produced by the refrigerant pressure reducing device.
  • the present invention may further include a propulsion compressor to increase the pressure of the boil-off gas undergoing the reliquefaction process, thereby further increasing the reliquefaction efficiency and reliquefaction amount.
  • FIG. 1 is a schematic view showing a conventional partial reliquefaction system.
  • Figure 2 is a schematic diagram showing a boil-off gas treatment system according to a first embodiment of the present invention.
  • FIG. 3 is a configuration diagram schematically showing a boil-off gas treatment system according to a second embodiment of the present invention.
  • FIG. 4 is a configuration diagram schematically showing a system for treating boil-off gas in accordance with a third embodiment of the present invention.
  • FIG. 5 is a configuration diagram schematically showing a boil-off gas treatment system according to a fourth embodiment of the present invention.
  • Figure 6 is a schematic diagram showing a system for treating the boil-off gas in accordance with a fifth embodiment of the present invention.
  • FIG. 7 is a configuration diagram schematically showing a boil-off gas treatment system according to a sixth embodiment of the present invention.
  • 9 is a graph showing the temperature values of methane according to the amount of heat flow under different pressures.
  • the vessel of the present invention can be applied to various applications, such as a vessel equipped with an engine using natural gas as a fuel, and a vessel including a liquefied gas storage tank.
  • a vessel equipped with an engine using natural gas as a fuel and a vessel including a liquefied gas storage tank.
  • the following examples may be modified in many different forms, and the scope of the present invention is not limited to the following examples.
  • the system for the treatment of boil-off gas to be described later of the present invention includes all kinds of vessels and offshore structures, that is, liquefied natural gas carriers, liquefied ethane gas carriers, equipped with storage tanks capable of storing low temperature liquid cargo or liquefied gas, It can be applied to ships such as LNG RV, as well as offshore structures such as LNG FPSO, LNG FSRU.
  • LNG RV liquefied natural gas carriers
  • LNG FPSO liquefied ethane gas carriers
  • the fluid in each line of the present invention may be in any one of a liquid state, a gas-liquid mixed state, a gas state, and a supercritical fluid state, depending on the operating conditions of the system.
  • FIG. 1 is a schematic view showing a conventional partial reliquefaction system.
  • the boil-off gas generated and discharged from the storage tank for storing the liquid cargo is transferred along the pipe and compressed in the boil-off gas compression unit 10.
  • the storage tank (T) has a sealing and insulation barrier to store liquefied gas such as liquefied natural gas in a cryogenic state, but it cannot completely block the heat transmitted from the outside, and the liquefied gas evaporates continuously in the tank.
  • the internal pressure of the tank may be increased, and to prevent excessive increase in the tank pressure due to the boil-off gas, and to discharge the boil-off gas inside the storage tank to maintain an appropriate level of internal pressure, the boil-off gas compression unit 10 may be used. Supply.
  • the boil-off gas discharged from the storage tank and compressed in the boil-off gas compression unit 10 is called a first stream
  • the first stream of compressed boil-off gas is divided into a second stream and a third stream
  • the second stream is liquefied. It is configured to return to the storage tank (T), and the third stream can be configured to supply to a gas fuel consumer such as a propulsion engine or a power generation engine on board.
  • the boil-off gas compression unit 10 may compress the boil-off gas to the supply pressure of the fuel consumer, and the second stream may branch through all or part of the boil-off gas compression unit as necessary.
  • all of the compressed boil-off gas may be supplied to the third stream, or all of the compressed boil-off gas may be supplied to the second stream to return the compressed boil-off gas to the storage tank.
  • Gas fuel consumption sources include high pressure gas injection engines (eg, ME-GI engines developed by MDT) and low pressure gas injection engines (eg, Wartsila's Generation X-Dual Fuel engine). ), DF Generator, gas turbine, DFDE and the like.
  • the heat exchanger 20 is installed to liquefy the second stream of compressed boil-off gas, and the boil-off gas generated from the storage tank is used as a cold heat source of the compressed boil-off gas.
  • the compressed boil-off gas, ie, the second stream, which has risen in temperature during the compression in the boil-off gas compression unit while passing through the heat exchanger 20 is cooled, and the boil-off gas generated in the storage tank and introduced into the heat exchanger 20 is heated. And is supplied to the boil-off gas compression unit 10.
  • the second stream of compressed boil-off gas may be supplied with cold heat from the boil-off gas before being compressed to at least partially liquefy.
  • the heat exchanger heat-exchanges the low-temperature evaporated gas immediately after being discharged from the storage tank and the high-pressure evaporated gas compressed by the evaporated gas compression unit to liquefy the high-pressure evaporated gas.
  • the boil-off gas of the second stream passing through the heat exchanger 20 is further cooled while being decompressed while passing through expansion means 30 such as an expansion valve or expander, and is supplied to the gas-liquid separator 40.
  • expansion means 30 such as an expansion valve or expander
  • the liquefied boil-off gas is separated from the gas and the liquid component in the gas-liquid separator, and the liquid component, that is, the liquefied natural gas, is returned to the storage tank, and the gas component, that is, the boil-off gas, is discharged from the storage tank so as to exchange the heat exchanger 20 and the boil-off gas.
  • the evaporation gas flow supplied to the compression unit 10 is joined to the evaporation gas flow, or supplied to the heat exchanger 20 and used as a cold heat source for heat-exchanging the high-pressure evaporation gas compressed by the evaporation gas compression unit 10. May be Of course, it may be sent to a gas combustion unit (GCU) or the like for combustion, or may be sent to a gas consumer (including a gas engine) for consumption.
  • GCU gas combustion unit
  • Another expansion means 50 may be further installed to further depressurize the gas separated in the gas-liquid separator before joining the boil-off gas stream.
  • Figure 2 is a schematic diagram showing a boil-off gas treatment system according to a first embodiment of the present invention.
  • the system of the present embodiment is characterized in that the refrigerant circulation section 300a for receiving the boil off gas generated from the low temperature liquid cargo stored in the storage tank to circulate the boil off gas to the refrigerant .
  • a refrigerant supply line for supplying the boil-off gas from the storage tank to the refrigerant circulation unit 300a
  • the valve supply line is provided with a valve 400a, a sufficient amount of evaporation gas to circulate the refrigerant circulation unit
  • the refrigerant circulation unit 300a is operated in a closed loop (closed loop).
  • the first compressor 100a is provided to compress the boil-off gas generated from the low temperature liquid cargo of the storage tank T.
  • the boil-off gas generated in the storage tank is introduced into the first compressor 100a along the boil-off gas supply line BLa.
  • the storage tank T of the present embodiments may be made of an independent type tank in which the load of liquid cargo is not directly applied to the insulation layer, or a membrane type tank in which the load of cargo is directly applied to the insulation layer. Can be.
  • independent tank type tanks it is also possible to use a pressure vessel designed to withstand pressures of 2 barg or more.
  • the boil-off gas compressed by the first compressor 100a is fueled to a fuel demand including a propulsion engine and a power generation engine of a ship or offshore structure. May be supplied, and there may be no boil-off gas that is reliquefied when the fuel consumption can consume the whole boil-off gas.
  • the gaseous fuel consumption is low or absent, such as when the ship is anchored, the entire amount of the boil-off gas may be supplied to the reliquefaction line RLa.
  • the compressed boil-off gas is supplied to the first heat exchanger 200a along the boil-off gas reliquefaction line RLa, and the first heat exchanger 200a is the boil-off gas reliquefaction line RLa and the boil-off gas supply line BLa. It is provided over, and heat exchanges the boil-off gas to be introduced into the first compressor (100a) and the boil-off gas compressed through at least a portion of the first compressor (100a).
  • the boil-off gas whose temperature is increased in the compression process is cooled by heat exchange with the low-temperature boil-off gas generated in the storage tank and introduced into the first compressor 100a.
  • a second heat exchanger 500a is provided downstream of the first heat exchanger 200a, and the boil-off gas heat-exchanged in the first heat exchanger 200a after the compression is exchanged with an evaporation gas circulating through the refrigerant circulation part 300a. Further cooling.
  • the refrigerant circulation unit 300a includes a refrigerant compressor 310a for compressing the evaporated gas supplied from the storage tank, a first cooler 320a for cooling the evaporated gas compressed by the refrigerant compressor, and a first cooler 320a. And a refrigerant pressure reducing device 330a for further cooling by reducing the cooled boil-off gas.
  • the refrigerant decompression device 330a may be an expansion valve or an expander that adiabatically expands and cools the boil-off gas.
  • the boil-off gas cooled through the refrigerant decompression device 330a is supplied to the second heat exchanger 500a as a refrigerant along the refrigerant circulation line CCLa, so that the first heat exchanger 200a is transferred from the second heat exchanger 500a.
  • the boil-off gas is cooled through heat exchange with the boil-off gas.
  • the boil-off gas of the refrigerant circulation line CCLa passing through the second heat exchanger 500a is circulated to the refrigerant compressor 310a to circulate the refrigerant circulation line through the above-described compression and cooling process.
  • the first pressure reducing device 600a may be an expansion valve such as a Joule-Thomson valve or an expander.
  • the pressurized boil-off gas is supplied to the gas-liquid separator 700a downstream of the first decompression device 600a and gas-liquid separated, and the liquid separated from the gas-liquid separator 700a, that is, liquefied natural gas, is supplied to the storage tank T. Restored.
  • the gas separated from the gas-liquid separator 700a ie, the boil-off gas
  • It may be used as a cold heat source that joins the gas stream or is supplied to the first heat exchanger 200a to heat-exchange the boil-off gas under high pressure compressed by the first compressor 100a.
  • it may be sent to a gas combustion unit (GCU) for combustion, or may be sent to a fuel demand (including a gas engine) for consumption.
  • GCU gas combustion unit
  • FIG. 3 is a configuration diagram schematically showing a boil-off gas treatment system according to a second embodiment of the present invention.
  • an evaporation gas to be introduced into the refrigerant decompression device 330b from the first cooler 320b in the refrigerant circulation part 300b is exchanged with the evaporated gas decompressed by the refrigerant decompression device 330b. After cooling to, it is configured to supply to the refrigerant pressure reducing device (330b).
  • the evaporation gas downstream of the refrigerant decompression device is lower in temperature than the evaporation gas upstream of the refrigerant decompression device.
  • the boil-off gas upstream of the refrigerant reducing device 330b may be supplied to the second heat exchanger 500b (part A of FIG. 3). If necessary, a separate heat exchanger may be further configured to exchange heat with the boil-off gas upstream and downstream of the refrigerant pressure reducing device.
  • the system of the embodiments may re-liquefy and store the evaporated gas generated from the storage tank liquid cargo, thereby increasing the transport rate of the liquid cargo.
  • the gas compression unit GCU
  • GCU gas combustion unit
  • FIG. 4 is a configuration diagram schematically showing a system for treating boil-off gas in accordance with a third embodiment of the present invention.
  • the first heat exchanger 110 is installed downstream of the storage tank (T); A first compressor 120 and a second compressor 122 installed downstream of the first heat exchanger 110 to compress the boil-off gas discharged from the storage tank T; A first cooler 130 for lowering the temperature of the boil-off gas compressed by the first compressor 120; A second cooler 132 for lowering the temperature of the boil-off gas compressed by the second compressor 122; A first valve 191 installed upstream of the first compressor 120; A second valve 192 installed downstream of the first cooler 130; A third valve 193 installed upstream of the second compressor 122; A fourth valve 194 installed downstream of the second cooler 132; A second heat exchanger 140 for further cooling the boil-off gas cooled by the first heat exchanger 110; A refrigerant pressure reducing device (160) for expanding the boil-off gas passing through the second heat exchanger (140) and sending it back to the second heat exchanger (140); And a first pressure reducing device 150 for expanding the boil-off gas further cooled by the second heat exchanger 140.
  • the boil-off gas naturally generated in the storage tank T and then discharged is supplied to the fuel demand 180 along the first supply line L1.
  • the first heat exchanger 110 is installed in the first supply line (L1) to recover the cold heat from the boil-off gas immediately after being discharged from the storage tank (T).
  • the vessel of the present embodiment may further include an eleventh valve 203 installed upstream of the fuel demand unit 180 to control the flow rate and opening and closing of the boil-off gas sent to the fuel demand unit 180.
  • the first heat exchanger 110 receives the boil-off gas discharged from the storage tank T, and uses the boil-off gas to cool the boil-off gas supplied to the first heat exchanger 110 along the return line L3.
  • a fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
  • the first compressor 120 and the second compressor 122 compress the boil-off gas passed through the first heat exchanger 110.
  • the first compressor 120 is installed on the first supply line L1
  • the second compressor 122 is installed on the second supply line L2.
  • the second supply line L2 branches from the first supply line L1 upstream of the first compressor 120 and is connected to the first supply line L1 downstream of the first compressor 120.
  • the first compressor 120 and the second compressor 122 may be installed in parallel and may be compressors having the same performance.
  • a ship additionally installs a second compressor 122 and a second cooler 132 in case the first compressor 120 and the first cooler 130 fail.
  • the 2nd compressor 122 and the 2nd cooler 132 were not used normally when the 1st compressor 120 or the 1st cooler 130 did not fail.
  • the fourth valve 193 upstream of the second compressor 122 and the fourth downstream of the second cooler 132 are normally used.
  • the valve 194 was closed to allow boil-off gas to pass through the first compressor 120 and the first cooler 130 to be supplied to the fuel demand 180, and the first compressor 120 or the first cooler 130 was In case of a failure, the third valve 193 upstream of the second compressor 122 and the fourth valve 194 downstream of the second cooler 132 are opened, and the first valve 191 upstream of the first compressor 120 is opened.
  • the second valve 192 downstream of the first cooler 130 is closed to allow the boil-off gas to be supplied to the fuel demand 180 through the second compressor 122 and the second cooler 132.
  • the present invention is to improve the re-liquefaction efficiency and the amount of re-liquefaction of the boil-off gas by using the second compressor 122 and the second cooler 132, which has not been used in the prior art installed on the ship, the second compressor 122
  • the evaporated gas compressed by) is sent to the fuel demand unit 180, and the other part is used as a refrigerant to further cool the evaporated gas in the second heat exchanger 140.
  • the methane is in a supercritical fluid state at a temperature of about ⁇ 80 ° C. or more and a pressure of about 55 bar or more. That is, in the case of methane, the critical point is about -80 °C, 55bar state.
  • the supercritical fluid state is a third state different from the liquid state or the gas state.
  • the boil-off gas compressed by the first compressor 120 or the second compressor 122 may be in a gaseous state or a supercritical fluid state depending on the degree of compression.
  • the boil-off gas sent to the first heat exchanger 110 through the return line L3 When the boil-off gas sent to the first heat exchanger 110 through the return line L3 is in a gaseous state, the boil-off gas passes through the first heat exchanger 110 and the temperature is lowered to become a mixed state of liquid and gas. In the case of the supercritical fluid state, the temperature may be lowered while passing through the first heat exchanger 110 to become a “high pressure liquid state”.
  • the boil-off gas cooled by the first heat exchanger 110 has a lower temperature while passing through the second heat-exchanger 140.
  • the boil-off gas passed through the first heat exchanger 110 is mixed with liquid and gas.
  • the boil-off gas passes through the second heat exchanger 140, and the temperature is lowered so that the proportion of the liquid becomes a mixed state or becomes a liquid state, and in the case of the "high pressure liquid state", the second heat exchanger The temperature is lowered while passing through 140.
  • the boil-off gas passing through the second heat exchanger 140 is in the "high-pressure liquid state"
  • the boil-off gas passes through the first pressure reducing device 150 to lower the pressure to become a liquid state or a mixed state of liquid and gas.
  • the boil-off gas is lowered to the same degree (P in FIG. 8) by the first decompression device 150, the temperature is lower than that in the case where the temperature of the boil-off gas is reduced (X ⁇ X ′ in FIG. 8). It can be seen that when the pressure is reduced in the state (Y ⁇ Y ′ in FIG. 8), the proportion of the liquid becomes a higher mixed state. In addition, it can be seen that if the temperature can be further lowered, theoretically, 100% of the evaporated gas can be reliquefied (Z ⁇ Z ′ in FIG. 8). Therefore, if the boil-off gas is further cooled by the second heat exchanger 140 before passing through the first pressure reducing device 150, the re-liquefaction efficiency and the amount of re-liquefaction may be increased.
  • the present embodiment compares the refrigerant cycles 300a and 300b for additionally cooling the boil-off gas in the first and second embodiments to form a closed loop.
  • the difference is that it consists of a loop.
  • the refrigerant circulation parts 300a and 300b are configured as closed loops, and the boil-off gas compressed by the refrigerant compressors 310a and 310b is cooled in the second heat exchangers 500a and 500b. It cannot be sent to fuel demand or reliquefed.
  • the refrigerant cycle is configured as an open loop, and the boil-off gas compressed by the second compressor 122 is combined with the boil-off gas compressed by the first compressor 120, and then the Some are sent to the fuel demand 180, the other is used as the second heat exchanger 140 refrigerant along the recirculation line (L5), the other part is subjected to the reliquefaction process along the return line (L3).
  • the recirculation line L5 is a line branching from the first supply line L1 downstream of the first compressor 120 and connected to the first supply line L1 upstream of the first compressor 120.
  • a sixth valve 196 may be installed to control the flow rate and opening / closing of the boil-off gas. .
  • the downstream line of the first compressor 120 and the downstream line of the second compressor 122 are connected as compared with the first and second embodiments in which the refrigerant cycle is configured as a closed loop.
  • the second supply line L2 downstream of the second compressor 122 is connected to the first supply line L1 downstream of the first compressor 120 and is connected by the second compressor 122.
  • the compressed boil-off gas is combined with the boil-off gas compressed by the first compressor 120, and then sent to the second heat exchanger 140, the fuel demand 180, or the first heat exchanger 110.
  • This embodiment includes both other variants in which the first compressor 120 downstream line and the second compressor 122 downstream line are connected.
  • the second compressor 122 as well as the boil-off gas compressed by the first compressor 120 may be used. Compressed gas may also be sent to the fuel demand (180).
  • the first compressor 120 and the second compressor 122 are designed to have a capacity of approximately 1.2 times the amount required by the fuel demand 180, the capacity of the first compressor 120 exceeds the capacity of the first compressor 120. Therefore, the case where the boil-off gas compressed by the second compressor 122 also needs to be sent to the fuel demand 180 is hardly generated. Rather, it is not possible to consume all of the evaporated gas discharged from the storage tank T in the fuel demand unit 180, and the amount of the evaporated gas to be reliquefied increases. More frequent
  • the boil-off gas compressed by the first compressor 120 can be used as a refrigerant for heat exchange in the second heat exchanger 140.
  • the boil-off gas supplied to the second heat exchanger 140 along the return line L3 may be cooled to a lower temperature using more refrigerant, and overall ash Liquefaction efficiency and reliquefaction amount can be increased, theoretically 100% reliquefaction is also possible.
  • the capacity required to supply the boil-off gas to the fuel demand (180), and the remaining boil-off gas not consumed by the fuel demand (180) to liquefy Considering all the capacity required to make, but according to the present embodiment can be used to increase the amount of re-liquefaction using the second compressor 122, it is possible to reduce the capacity required for re-liquefaction, so that a small capacity compressor 120 122) can be installed. Reducing the capacity of the compressor has the advantage of reducing both equipment installation and operating costs.
  • the valve 194 is also opened to operate the first compressor 120, the first cooler 130, the second compressor 122, and the second cooler 132, and to operate the first compressor 120 or the first cooler.
  • the first valve 191 and the second valve 192 are closed and the second compressor 122 and the second cooler 132 are given up to increase the reliquefaction efficiency and the amount of reliquefaction. Operate the system only with boil-off gas that has passed through.
  • the first compressor 120 and the first cooler 130 play a main role
  • the second compressor 122 and the second cooler 132 play an auxiliary role
  • the compressor 120, the second compressor 122, the first cooler 130, and the second cooler 132 have the same role, and are provided with two or more compressors and coolers having the same role in one ship.
  • the concept of redundancy is satisfied in that one device can be replaced by another in case of failure. The same applies to the following.
  • the third valve 193 and the fourth valve 194 are closed to operate the system using only the boil-off gas passed through the first compressor 120 and the first cooler 130.
  • the ship when the ship is operated at a speed such that most or all of the boil-off gas discharged from the storage tank T can be used as fuel for the fuel demand unit 180, the amount of the boil-off gas to be reliquefied is very small. With or without. Therefore, when the ship is operating at a high speed, only one of the first compressor 120 or the second compressor 122 may be driven.
  • the first compressor 120 and the second compressor 122 may compress the boil-off gas to the pressure required by the fuel demand 180, the fuel demand 180 may be an engine, a generator, etc. driven by the boil-off gas as fuel. have.
  • the first compressor 120 and the second compressor 122 may compress the boil-off gas to a pressure of approximately 10 to 100 bar.
  • the first compressor 120 and the second compressor 122 may compress the boil-off gas to a pressure of approximately 150 bar to 400 bar, and the fuel demand unit 180 may be used.
  • the boil-off gas can be compressed to a pressure of approximately 6.5 bar, and if the fuel demand 180 is an X-DF engine, the boil-off gas can be compressed to a pressure of approximately 16 bar.
  • the fuel demand 180 may include various types of engines.
  • the first compressor 120 and the second compressor 122 may be X.
  • the first compressor 120 or the second compressor 122 may provide Compresses the boil-off gas so that the pressure exceeds the pressure required by the fuel demand unit 180, and installs a decompression device upstream of the fuel demand unit 180, so that the pressure of the boil-off gas compressed to exceed the pressure required by the fuel demand unit 180 is The pressure may be lowered to the pressure required by the fuel demand 180 and then supplied to the fuel demand 180.
  • the first compressor 120 and the second compressor 122 may each be a multistage compressor.
  • FIG. 4 it is shown that one compressor 120 or 122 compresses the boil-off gas to the pressure required by the fuel demand 180, but the first compressor 120 and the second compressor 122 are multistage compressors.
  • the boil-off gas may be compressed several times to a pressure required by the fuel demand unit 180 by a plurality of compression cylinders.
  • first compressor 120 and the second compressor 122 are multistage compressors
  • a plurality of compression cylinders may be installed in series in the first compressor 120 and the second compressor 122, and the plurality of compression cylinders may be installed in series. Downstream, a plurality of coolers may be installed respectively.
  • the first cooler 130 of this embodiment is installed downstream of the first compressor 120 to cool the boil-off gas compressed by the first compressor 120 to raise not only the pressure but also the temperature, and the second cooler of the present embodiment.
  • 132 is provided downstream of the second compressor 122 to cool the boil-off gas compressed by the second compressor 122 to raise not only the pressure but also the temperature.
  • the first cooler 130 and the second cooler 132 may cool the boil-off gas through heat exchange with seawater, fresh water or air introduced from the outside.
  • the second heat exchanger 140 of the present embodiment further cools the boil-off gas supplied to the second heat exchanger 140 along the return line L3 after being cooled by the first heat exchanger 110, and performs the present embodiment.
  • the refrigerant reducing device 160 of the example expands the boil-off gas passing through the second heat exchanger 140 and then sends the same to the second heat exchanger 140.
  • the second heat exchanger 140 passes through the first heat exchanger 110 and then supplies the boil-off gas supplied to the second heat exchanger 140 along the return line L3 to the refrigerant pressure reducing device 160.
  • the evaporated gas thus expanded is heat-exchanged with a refrigerant and further cooled.
  • the refrigerant pressure reducing device 160 of the present embodiment may be various means for lowering the pressure of the fluid, and the state of the fluid immediately before passing through the refrigerant pressure reducing device 160 and the state of the fluid immediately after the passage are dependent on the operating conditions of the system. It may vary. However, when the refrigerant pressure reducing device 160 is an expander, in order to prevent physical damage of the refrigerant pressure reducing device 160, the fluid immediately before passing through the refrigerant pressure reducing device 160 and the fluid immediately after passing are maintained in the gas phase. It is preferable to be. The same applies to the following.
  • the boil-off gas used as the refrigerant for heat exchange in the second heat exchanger 140 is compressed by the second compressor 122 by the boil-off gas compressed by the first compressor 120.
  • a part of the combined evaporated gas is supplied to the second heat exchanger 140 along the recirculation line (L5), passing through the refrigerant pressure reducing device 160 in the second heat exchanger (140)
  • the evaporated gas is cooled by heat exchange with a refrigerant and then supplied to the refrigerant decompression device 160.
  • the boil-off gas supplied from the first supply line (L1) to the second heat exchanger 140 along the recycle line (L5) is first cooled in the second heat exchanger (140) to the refrigerant pressure reducing device (160). After the additional cooling is sent to the second heat exchanger 140 is used as a refrigerant.
  • the first pressure reducing device 150 of the present embodiment is installed on the return line L3 to expand the boil-off gas cooled by the first heat exchanger 110 and the second heat exchanger 140.
  • the boil-off gas compressed by the first compressor 120 merges with the boil-off gas compressed by the second compressor 122 and partially branches the first boil-off heat exchanger 110 and the first heat exchanger along the return line L3. 2 is passed through the heat exchanger 140 and the first pressure reducing device 150 and part or all of it is reliquefied.
  • the first pressure reducing device 150 includes all means capable of expanding and cooling the boil-off gas and may be an expansion valve such as a Joule-Thomson valve or an expander.
  • the gas-liquid separator 170 is installed on the return line (L3) downstream of the first decompression device 150 and separates the gas-liquid mixture discharged from the first decompression device 150 into a gas and a liquid. It may include.
  • the liquid or gaseous gas in the gas-liquid mixed state passing through the first decompression device 150 is directly sent to the storage tank (T).
  • the boil-off gas passing through the first decompression device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase.
  • the liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
  • the vessel of the present embodiment includes a gas-liquid separator 170
  • the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T);
  • an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
  • the first to eighth valves and the eleventh valves of the present exemplary embodiment 191, 192, 193, 194, 195, 196, 197, 198, and 203 may be manually adjusted by a person directly determining a system operating situation. It may be automatically adjusted to open and close by a preset value.
  • the main flow of the boil-off gas is defined to easily explain the operation of the apparatus for boil-off gas reliquefaction according to an embodiment of the present invention.
  • the evaporation gas generated in the storage tank T and the gas discharged from the gas-liquid separator 170 are supplied to the first heat exchanger 110 by the first flow 100 and the first heat exchanger 110 by the first flow.
  • the flow discharged from the first compressor 120 or the second compressor 122 to the fuel demand 180 is supplied to the second flow 102 and the first compressor 122.
  • Downstream of the compressor 120 and the second compressor 122 flows branching from the second flow 102 to the second heat exchanger 140 are supplied to the third flow 104, the first compressor 120, and the second.
  • the supplied flow is defined as the fifth flow 108.
  • the first flow 100 passes through the first heat exchanger 110 and becomes the second flow 102, and the fourth flow 106 passes through the first heat exchanger 110 and the fifth flow 108 passes through the first heat exchanger 110. do.
  • the gaseous evaporated gas generated in the storage tank T storing the liquid liquefied gas is supplied to the first heat exchanger 110.
  • the gaseous evaporated gas generated in the storage tank (T) meets the gaseous evaporated gas discharged from the gas-liquid separator 170 after a predetermined time after the system operation to form the first flow (100). do.
  • the boil-off gas supplied to the first heat exchanger 110 is the first flow 100.
  • the first heat exchanger 110 recovers the cold heat of the first flow 100 and cools other boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the first flow 100 and is supplied again to the first heat exchanger 110 of the second flow 102, that is, the fourth flow. The recovered cold heat is transferred to 106.
  • first heat exchanger 110 heat exchange occurs between the first flow 100 and the fourth flow 106, such that the first flow 100 is heated and the fourth flow 106 is cooled.
  • the heated first flow 100 becomes the second flow 102 and the cooled fourth flow 106 becomes the fifth flow 108.
  • the second stream 102 discharged from the first heat exchanger 110 is supplied to the first compressor 120 or the second compressor 122, and is supplied by the first compressor 120 or the second compressor 122. Is compressed.
  • the second flow 102 in which the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the second compressor 122 joins, is part of the second heat exchanger 140 as the third flow 104.
  • Is supplied as a refrigerant and the other part is supplied to the first heat exchanger 110 as a fourth flow 106 to be cooled, and the other part is supplied to the fuel demand 180.
  • the third flow 104 supplied to the second heat exchanger 140 is discharged from the second heat exchanger 140, expanded in the refrigerant pressure reducing device 160, and then supplied to the second heat exchanger 140.
  • the third flow 104 which is primarily supplied to the second heat exchanger 140, is expanded by the refrigerant pressure reducing device 160, and then the third flow 104 is supplied to the second heat exchanger 140 again. Heat exchanger) to cool.
  • the third flow 104 passing through the refrigerant pressure reducing device 160 and the second heat exchanger 140 joins the second flow 102 discharged from the first heat exchanger 110 to form the first compressor 120. ) Or to the second compressor 122.
  • the fourth flow 106 cooled by heat-exchanging with the first flow 100 in the first heat exchanger 110 becomes the fifth flow 108 and is supplied to the second heat exchanger 140.
  • the fifth flow 108 supplied to the second heat exchanger 140 is cooled by heat exchange with the third flow 104 passed through the refrigerant pressure reducing device 160, and then passes through the first pressure reducing device 150. Swell.
  • the fifth flow 108 through the first pressure reducing device 150 is in a gas-liquid mixture, in which gas and liquid are mixed.
  • the fifth stream 108 in the gas-liquid mixture is directly sent to the storage tank T or separated into gas and liquid while passing through the gas-liquid separator 170.
  • the liquid separated by the gas-liquid separator 170 is supplied to the storage tank T, and the gas separated by the gas-liquid separator 170 is supplied to the first heat exchanger 110 to repeat the above processes.
  • FIG. 5 is a configuration diagram schematically showing a boil-off gas treatment system according to a fourth embodiment of the present invention.
  • the ship of the fourth embodiment shown in FIG. 5 has an additional compressor 124 and an additional cooler 134 installed in the second supply line L2 and a return line, compared to the ship of the third embodiment shown in FIG. 4. Further comprising a propulsion compressor 126 and the propulsion cooler 136 installed in (L3), and the ninth valve 201, the tenth valve 202, the twelfth valve 205 and the first additional line ( L6) is further included, and a difference exists in that the refrigerant cycle can be operated in a closed loop or in an open loop by modifying some lines through which the evaporated gas flows. do. Detailed descriptions of the same members as those of the ship of the third embodiment are omitted.
  • the vessel of the present embodiment like the third embodiment, includes the first heat exchanger 110, the first valve 191, the first compressor 120, the first cooler 130, and the second.
  • Valve 192, third valve 193, second compressor 122, second cooler 132, fourth valve 194, second heat exchanger 140, refrigerant pressure reducing device 160, and 1 includes a decompression device 150.
  • the storage tank T of the present embodiment stores the liquefied gas such as liquefied natural gas and liquefied ethane gas inside, and discharges the boil-off gas to the outside when the internal pressure is higher than the predetermined pressure.
  • the boil-off gas discharged from the storage tank T is sent to the first heat exchanger 110.
  • the first heat exchanger 110 uses the evaporated gas discharged from the storage tank T as the refrigerant, and returns to the first heat exchanger 110 along the return line L3. Cool the sent boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the boil-off gas discharged from the storage tank T, and recovers the collected cold heat to the boil-off gas sent to the first heat exchanger 110 along the return line L3. Supply.
  • a fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
  • the first compressor 120 of the present embodiment is installed on the first supply line L1 to compress the boil-off gas discharged from the storage tank T, and the second compressor of the present embodiment ( As in the third embodiment, 122 is installed in parallel with the first compressor 120 on the second supply line L2 to compress the boil-off gas discharged from the storage tank T.
  • the first compressor 120 and the second compressor 122 may be compressors of the same performance, and may each be a multistage compressor.
  • the first compressor 120 and the second compressor 122 of the present embodiment can compress the boil-off gas to the pressure required by the fuel demand 180.
  • some of the high pressures are compressed after compressing the boil-off gas in accordance with a required pressure of an engine requiring higher pressure (hereinafter, referred to as a 'high pressure engine'). It can be supplied to the engine, and the other part can be supplied to the low pressure engine after being depressurized by a pressure reducing device installed upstream of the engine requiring a lower pressure (hereinafter referred to as a 'low pressure engine').
  • the boil-off gas is fueled by the first compressor 120 or the second compressor 122. It is compressed to a high pressure higher than the pressure required by the customer 180, and a pressure reducing device is provided upstream of the fuel demand 180 to lower the pressure of the boiled gas compressed to a high pressure to the pressure required by the fuel demand 180, and then the fuel demand. 180 may be supplied.
  • the vessel of this embodiment further includes an eleventh valve 203 which is provided upstream of the fuel demand unit 180 and regulates the flow rate and opening and closing of the boil-off gas sent to the fuel demand unit 180. Can be.
  • the vessel of this embodiment uses the boil-off gas compressed by the second compressor 122 as a refrigerant for further cooling the boil-off gas in the second heat exchanger 140, so that the re-liquefaction efficiency and re- The amount of liquefaction can be increased.
  • the first cooler 130 of the present embodiment is installed downstream of the first compressor 120 and cools the evaporated gas that passes not only the pressure but also the temperature through the first compressor 120
  • the second cooler 132 of the present embodiment is installed downstream of the second compressor 122 to cool the evaporated gas that passes not only the pressure but also the temperature through the second compressor 122.
  • the second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 and is cooled by the first heat exchanger 110. Cool additionally.
  • the boil-off gas discharged from the storage tank T is additionally cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, so that the temperature is lower. Furnace can be supplied to the first decompression device 150, the re-liquefaction efficiency and the amount of re-liquefaction is increased.
  • the refrigerant pressure reducing device 160 expands the boil-off gas passed through the second heat exchanger 140 and sends it to the second heat exchanger 140 in the same manner as in the third embodiment.
  • the first pressure reducing device 150 of the present embodiment is installed on the return line L3 and is cooled by the first heat exchanger 110 and the second heat exchanger 140. Inflate.
  • the first pressure reducing device 150 of the present embodiment includes all means capable of expanding and cooling the boil-off gas, and may be an expansion valve such as a Joule-Thomson valve or an expander.
  • the vessel of the present embodiment is installed on the return line L3 downstream of the first pressure reducing device 150 and separates the gas-liquid mixture discharged from the first pressure reducing device 150 into gas and liquid.
  • Gas-liquid separator 170 may be included.
  • the vessel of this embodiment when the vessel of this embodiment does not include the gas-liquid separator 170, the liquid or gaseous-mixed evaporated gas that has passed through the first decompression device 150 is directly sent to the storage tank T.
  • the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first pressure reducing device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase.
  • the liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
  • the vessel of the present embodiment includes the gas-liquid separator 170, like the third embodiment, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T) ); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
  • the additional compressor 124 is installed on the second supply line (L2); An additional cooler 134 installed downstream of the additional compressor 124; A propulsion compressor 126 installed on the return line L3; A propulsion cooler 136 installed downstream of the propulsion compressor 126; A first additional line L6 connecting between the recirculation line L5 and the second supply line L2; A ninth valve 201 installed on the recirculation line L5; A tenth valve 202 installed on the first additional line L6; And a twelfth valve 205 installed on the recirculation line L5 between the second supply line L2 and the second heat exchanger 140.
  • the ship of the present embodiment unlike the third embodiment, which selectively includes a sixth valve, the recirculation line (2) in which the boil-off gas branched from the first supply line (L1) is sent to the second heat exchanger 140 ( It is provided on the L5), and essentially includes a sixth valve (196) for controlling the flow rate and opening and closing of the boil-off gas.
  • the additional compressor 124 of the present embodiment may be installed upstream or downstream of the second compressor 122 on the second supply line L2 and may have a smaller capacity than the second compressor 122.
  • the additional compressor 124 may be driven by the power produced by the refrigerant pressure reducing device 160 while expanding the fluid, and the capacity of the additional compressor 124 may be driven by power generated by the refrigerant pressure reducing device 160. It may be a dose that can be.
  • the refrigerant reducing device 160 uses the power generated by expanding the fluid in the additional compressor 124 will be described as an example, but the power generated by the refrigerant reducing device 160 will be described as the first compressor 120.
  • the system may be configured for use in the second compressor 122.
  • Compressors include centrifugal compressors that rotate the vanes at high speed to compress gas with energy from centrifugal force, reciprocating compressors that compress the gas by reciprocating the piston in the cylinder, and two rotors.
  • a screw compressor for compressing the gas by the engagement of the reciprocating compressor and the screw compressor, of which belongs to the volumetric compressor (Positive Displacement Compressor) for compressing the gas sucked in a constant volume.
  • the first compressor 120 and the second compressor 122 of the present embodiment are volumetric compressors, and the additional compressor 124 is preferably a centrifugal compressor, and the additional compressor 124 is the second compressor 122.
  • the second compressor 122 compresses the same flow rate as the first compressor 120, so that the mass flow rate of the boil-off gas passing through the second supply line L2 is the same and only the pressure is increased. Occurs.
  • the additional compressor 124 is installed upstream of the second compressor 122, the second compressor 122 is supplied with the boil-off gas which is compressed by the additional compressor 124 and has a high density. The mass flow rate of the boil-off gas supplied to 122 can be increased.
  • the additional compressor 124 when the additional compressor 124 is installed upstream of the second compressor 122, the boil-off gas supplied from the storage tank T and supplied to the second supply line L2 is compressed by the additional compressor 124.
  • the mass of the boil-off gas supplied to the second compressor 122 becomes larger even if the boil-off gas of the same flow rate is supplied to the second compressor 122.
  • the mass of the fluid used as the refrigerant in the second heat exchanger 140 after being compressed by the second compressor 122 becomes larger, the reliquefaction efficiency and reliquefaction amount in the second heat exchanger 140 are increased. Can be increased.
  • the present embodiment can be operated as a closed loop and an independent open loop, and the outlet pressure of the second compressor 122 can be controlled by the first compressor ( It may be operated in an open loop by adjusting the outlet pressure of 120).
  • the additional compressor 124 when the additional compressor 124 is installed downstream of the second compressor 122, the mass flow rate is determined by the capacity of the second compressor 122, the additional compressor 124 only serves to increase the additional pressure. . This also can be expected to improve efficiency compared to the existing, but is limited, it is preferable that the additional compressor 124 is installed upstream of the second compressor (122).
  • the present embodiment may operate as a closed loop and an independent open loop, and the second supply gas and the second supply gas passed through the first supply line L1. Since the pressure of the boil-off gas passing through the line (L2) is different from each other, it may be difficult to operate in an open loop.
  • the power generated by the refrigerant pressure reducing device 160 can be utilized, and by adding an additional compressor 124, the reliquefaction efficiency and the amount of reliquefaction can be increased at a low cost.
  • the additional cooler 134 of the present embodiment lowers the temperature of the boil-off gas compressed by the additional compressor 124 and whose temperature as well as the pressure is increased.
  • the additional compressor 124 is installed upstream of the second compressor 122, the additional compressor 124, the additional cooler 134, the second compressor 122, and the second cooler 132 are installed in this order.
  • the compressor 124 is installed downstream of the second compressor 122, the second compressor 122, the second cooler 132, the additional compressor 124, and the additional cooler 134 are installed in this order.
  • the propulsion compressor 126 diverges a portion of the boil-off gas supplied to the fuel demand 180 along the first supply line L1 and sends it to the first heat exchanger 110 on the return line L3. Is installed in, to increase the pressure of the boil-off gas supplied to the first heat exchanger 110 along the return line (L3).
  • the propulsion compressor 126 may compress the boil-off gas to a pressure below the critical point (approximately 55 bar in the case of methane), or may compress it to a pressure above the critical point, the propulsion compressor 126 of the present embodiment evaporates If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.
  • the propulsion cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126 to lower the temperature of the boil-off gas that has passed through the propulsion compressor 126 and has risen in temperature as well as pressure.
  • the ship of this embodiment may further include a propulsion compressor 126 to increase the pressure of the boil-off gas undergoing the reliquefaction process, thereby increasing the amount of reliquefaction and reliquefaction efficiency.
  • Self- of self-heat exchange means that the low-temperature evaporation gas itself is used as a cooling fluid to exchange heat with the high-temperature evaporation gas.
  • FIG. 9A shows the state of each fluid in the second heat exchanger 140 when the propulsion compressor 126 and the propulsion cooler 136 are not included
  • FIG. 9B shows the propulsion.
  • the compressor 126 and the propulsion cooler 136 shows the state of each fluid in the second heat exchanger (140).
  • the uppermost graph I of FIGS. 9A and 9B shows the fluid state at the point A of FIG. 5 supplied to the second heat exchanger 140 along the recirculation line L5
  • Graph L is point C of FIG. 5 which is fed back to second heat exchanger 140 for use as a refrigerant after passing through second heat exchanger 140 and refrigerant pressure reducing device 160 along recirculation line L5.
  • 5 is a graph illustrating a fluid state of FIG. 5, which is overlapped with a graph K of the middle portion, and is supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110.
  • the fluid state at point E is shown.
  • the graph L proceeds from left to right with time, and the fluid heat-exchanged with the refrigerant cools the heat from the refrigerant during the heat exchange process. As the temperature is getting lower and lower, the graphs I and J progress from right to left over time.
  • the graph K of the middle part of FIG.9 (a) and (b) shows the graph I and the graph J combining. That is, the fluid used as the refrigerant in the second heat exchanger 140 is drawn by the graph L, and the fluid that is cooled by heat exchange with the refrigerant in the second heat exchanger 140 is drawn by the graph K.
  • the temperature and heat flow of the fluid supplied to the heat exchanger i.e., point A, point C and point E in FIG. 5 are fixed, and the temperature of the fluid used as the refrigerant is higher than the temperature of the fluid to be cooled.
  • LMTD Logarithmic Mean Temperature Difference
  • Logical mean temperature difference is a heat exchange method in which the hot fluid and the low temperature fluid are injected in opposite directions and discharged from the opposite direction.
  • the logarithmic mean temperature difference LMTD is represented by the interval between the low temperature fluid (graph L of FIG. 9) used as the refrigerant and the high temperature fluid (graph K of FIG. 9) cooled by heat exchange with the refrigerant.
  • graph L of FIG. 9 shows that the interval between the graph L and the graph K is narrower.
  • the fluid at the point E of FIG. 5 may be approximately ⁇ 111 ° C., 20 bar, and includes the propulsion compressor 126.
  • the fluid at point E of FIG. 5 may be approximately ⁇ 90 ° C. and 50 bar.
  • LMTD logarithmic mean temperature difference
  • the ship of the present embodiment includes the propulsion compressor 126, the reliquefaction amount and the reliquefaction efficiency can be increased, and the reliquefaction amount and the reliquefaction efficiency are increased to drive the second compressor 122 without the need to drive the second compressor 122. Since both cases can be increased, there is an advantage that the frequency of use of the second compressor 122 can be reduced.
  • the re-liquefaction efficiency can be increased by using the second compressor 122, the concept of redundancy that the longer the time for driving the second compressor 122 is to prepare for the failure of the first compressor 120 is It will weaken. Since the ship of this embodiment can reduce the frequency of use of the second compressor 122, including the propulsion compressor 126, the concept of redundancy can be sufficiently secured.
  • the propulsion compressor 126 is generally sufficient to have approximately 1/2 the capacity of the first compressor 120 or the second compressor 122, the propulsion compressor 126 is driven without driving the second compressor 122. In the case of operating the system by driving only the first compressor 120 and), it is possible to save the operating cost than when the propulsion compressor 126 is not installed.
  • one side of the first additional line L6 may expand the evaporated gas passing through the second heat exchanger 140 after being expanded by the refrigerant pressure reducing device 160 to the first supply line.
  • a recirculation line L5 which is sent to L1
  • the other side is connected to a second supply line L2 between the third valve 193 and the second compressor 122.
  • the ninth valve 201 of the present embodiment has a point where the recirculation line L5 meets the first supply line L1 upstream of the first compressor 120 and the second compressor 122, and the recirculation line L5 is Between the point where it meets the 1st additional line L6, it is installed on the recycle line L5.
  • the ship of the present embodiment the second supply line (L2) downstream of the second compressor 122 is connected to the recirculation line (L5), not the first supply line (L1).
  • the twelfth valve 205 of the present embodiment is installed on the recirculation line L5 between the second supply line L2 and the second heat exchanger 140 to regulate the flow rate and opening and closing of the fluid.
  • the first to twelfth valves 191, 192, 193, 194, 195, 196, 197, 198, 201, 202, 203, and 205 of the present embodiment may be manually adjusted by a person directly determining a system operating situation. It may be automatically adjusted to open and close by a preset value.
  • a feature that is different from the third embodiment of the ship of this embodiment is that the refrigerant cycle can be operated not only in the open loop but also in the closed loop, so that the reliquefaction system can be used more flexibly according to the operating conditions of the ship.
  • the additional compressor 124 is installed upstream of the second compressor 122, a method of operating a refrigerant cycle in a closed loop and a method of operating in an open loop through valve adjustment will be described.
  • the third valve 193 is closed to add the boil-off gas to the additional compressor 124.
  • Cooler 134, second compressor 122, second cooler 132, fourth valve 194, twelfth valve 205, second heat exchanger 140, refrigerant pressure reducing device 160, and A closed loop refrigerant cycle is formed to circulate the second heat exchanger 140 and the tenth valve 202.
  • the storage tank including the storage tank of the present embodiment may further include a pipe for introducing nitrogen gas into the refrigerant cycle of the closed loop.
  • the refrigerant cycle When the refrigerant cycle is operated as a closed loop, only the boil-off gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the boil-off gas passing through the first compressor 120 cannot be introduced into the refrigerant cycle. It is supplied to the fuel demand 180, or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction or the amount of boil-off gas required by the fuel demand unit 180, the boil-off gas of a constant flow rate is circulated to the refrigerant of the second heat exchanger 140.
  • the refrigerant cycle of the present embodiment When the refrigerant cycle of the present embodiment is operated in a closed loop, it is easier to control the flow rate of each of the evaporated gas that is undergoing the reliquefaction process and the evaporated gas used as the refrigerant compared to the case of operating the closed loop or the independent open loop. There is this.
  • the refrigerant cycle of the present embodiment is preferably operated as a closed loop or an independent closed loop. Do.
  • the boil-off gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, and a part of the fuel demand unit 180 is removed. The remaining part is subjected to the reliquefaction process along the return line (L3).
  • the boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled.
  • the boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
  • the boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and then twice in the first heat exchanger 110 and the second heat exchanger 140.
  • the boil-off gas compressed by the propulsion compressor 126 may be directly sent to the second heat exchanger 140 to be cooled, and then expanded and re-liquefied by the first pressure reducing device 150.
  • the refrigerant cycle of this embodiment is operated in an open loop and an independent open loop.
  • the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170.
  • the gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
  • the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the second compressor 122 and by the second cooler 132. Cooled and sent to the second heat exchanger 140 along the recycle line (L5). After passing through the additional compressor 124 and the second compressor 122, the boil-off gas sent to the second heat exchanger 140 is first heat-exchanged by the second heat exchanger 140, and then cooled. It is sent to the secondary expansion and cooled.
  • the boil-off gas used as the refrigerant along the recirculation line L5 passes first through the second heat exchanger 140 and then is sent back to the second heat exchanger 140 through the refrigerant pressure reducing device 160.
  • the evaporated gas used as the refrigerant along the recirculation line (L5) is sent directly to the refrigerant decompression device 160 without passing through the second heat exchanger 140, and then to the second heat exchanger 140. Can be sent. The same applies to the case where the refrigerant cycle of this embodiment is operated in an open loop and an independent open loop.
  • the evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
  • the first valve 191, the second valve 192, and the tenth valve 202 and the twelfth valve 205 are closed, the third valve 193 and the sixth valve 196 are opened, the evaporation passed through the first heat exchanger 110 after being discharged from the storage tank (T).
  • the gas is connected to the third valve 193, the additional compressor 124, the additional cooler 134, the second compressor 122, the second cooler 132, the fourth valve 194 and the sixth valve 196. To be supplied to the fuel demand unit 180.
  • the ninth valve 201 and the twelfth valve 205 are used. You can also open and operate the system.
  • the refrigerant cycle When the refrigerant cycle is operated as a closed loop, the boil-off gas circulating through the refrigerant cycle and the boil-off gas sent to the fuel demand 180 or undergoing reliquefaction along the return line L3 are separated.
  • the refrigerant cycle when the refrigerant cycle is operated as an open loop, the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the second compressor 122 are joined together, and the refrigerant is transferred from the second heat exchanger 140 to the refrigerant. It may be used, or may be sent to the fuel demand 180, or undergo a reliquefaction process along the return line (L3).
  • the flow rate of the refrigerant to be sent to the second heat exchanger 140 may be flexibly adjusted in consideration of the amount of reliquefaction and the amount of boil-off gas required by the fuel demand 180.
  • the amount of boil-off gas in the fuel demand unit 180 is small, increasing the flow rate of the refrigerant sent to the second heat exchanger 140 may increase the reliquefaction efficiency and the amount of reliquefaction.
  • the boil-off gas discharged from the storage tank T passes through the first heat exchanger 110 and then branches into two streams, partly to the first supply line L1, and the other part to the second supply line L2. Is sent to.
  • the boil-off gas sent to the first supply line L1 passes through the first valve 191, the first compressor 120, the first cooler 130, and the second valve 192, and a part thereof includes a sixth valve ( 196 and twelfth valve 205 are sent to second heat exchanger 140, the other part again diverging in two flows.
  • One stream of the boil-off gas branched into two streams is sent to the fuel demand unit 180, and the other is sent to the propulsion compressor 126 along the return line (L3).
  • the boil-off gas sent to the second supply line L2 includes a third valve 193, an additional compressor 124, an additional cooler 134, a second compressor 122, a second cooler 132, and a fourth valve ( After passing 194, a portion is passed through the twelfth valve 205 to the second heat exchanger 140, and another portion is sent to the first supply line L1 and branches into two flows.
  • One stream of the boil-off gas branched into two streams is sent to the fuel demand unit 180, and the other stream is sent to the propulsion compressor 126 along the return line (L3).
  • the evaporated gas compressed by the first compressor 120 and the evaporated gas compressed by the additional compressor 124 and the second compressor 122 are separated and described.
  • the boil-off gas compressed by the boil-off gas and the boil-off gas compressed by the additional compressor 124 and the second compressor 122 are not separately flowed, but joined together to form the second heat exchanger 140, the fuel demand 180, or the propulsion. It is supplied to the compressor 126.
  • the return line L3 the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the additional compressor 124 and the second compressor 122 flow.
  • the boil-off gas sent to the second heat exchanger 140 along the recirculation line L5 is first heat exchanged and cooled in the second heat exchanger 140, and is secondly expanded and cooled by the refrigerant pressure reducing device 160. Again supplied to the second heat exchanger (140). After passing through the refrigerant pressure reducing device 160, the boil-off gas supplied to the second heat exchanger 140 passes through the first heat exchanger 110 and then passes through the return line L3 to the second heat exchanger 140. Supplied boil-off gas; And the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the additional compressor 124 and the second compressor 122, supplied to the second heat exchanger 140 along the recirculation line L5. Heat exchange with the joined flow.
  • the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the first supply line L1 through the ninth valve 201, and is stored from the storage tank T. After the discharge, the first heat exchanger 110 is joined with the evaporated gas, and the above-described series of processes are repeated.
  • the boil-off gas sent to the propulsion compressor 126 along the return line L3 is compressed by the propulsion compressor 124, cooled by the propulsion cooler 134, and then sent to the first heat exchanger 110. Lose.
  • the boil-off gas sent to the first heat exchanger 110 is first cooled in the first heat exchanger 110, secondly cooled in the second heat exchanger 140, and then expanded by the first pressure reducing device 150.
  • the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170.
  • the gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
  • the first valve 191, the second valve 192, and the ninth valve 201 and the 12th valve 205 are closed, and the boil-off gas which passed through the 1st heat exchanger 110 after discharge
  • the ninth valve 201 and the twelfth valve 205 are used. You can also open and operate the system.
  • the vessel of the present embodiment operates the refrigerant cycle in an open loop
  • the boil-off gas compressed by the second compressor 122 is used only as the refrigerant of the second heat exchanger 140 and is compressed by the first compressor 120.
  • the evaporated gas is sent to the fuel demand unit 180 or undergoes a reliquefaction process along the return line L3, and the second compressor 122 and the second compressor 122 are not used as the refrigerant of the second heat exchanger 140.
  • 1 compressor 120 may be operated independently.
  • the refrigerant cycle of the open loop for independently operating the second compressor 122 and the first compressor 120 is referred to as an 'independent open loop'.
  • the twelfth valve 205 is opened, and the sixth valve 196 and the tenth valve 202 are closed.
  • the boil-off gas discharged from the storage tank T passes through the first heat exchanger 110 and then branches into two streams, partly to the first supply line L1, and partly to the second supply line L2. Is sent.
  • the boil-off gas sent to the first supply line L1 passes through the first valve 191, the first compressor 120, the first cooler 130, and the second valve 192, and a part of the fuel demand 180 ) And the other part to the propulsion compressor 126 along the return line (L3).
  • the boil-off gas sent to the second supply line L2 may include a third valve 193, an additional compressor 124, an additional cooler 134, a second compressor 122, a second cooler 132, and a fourth valve ( After passing through the 194 and the twelfth valves 205, it is sent to the second heat exchanger 140 along the recirculation line L5.
  • the boil-off gas which is compressed by the additional compressor 124 and the second compressor 122, and then sent to the second heat exchanger 140 along the recirculation line L5, is first heat-exchanged by the second heat exchanger 140 and cooled.
  • the second heat exchanger After the second expansion by the refrigerant pressure reducing device 160 is cooled and supplied again to the second heat exchanger 140, the second heat exchanger through the return line (L3) after passing through the first heat exchanger (110) Boil-off gas supplied to the unit 140; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5.
  • the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the first supply line L1 through the ninth valve 201, and is stored from the storage tank T. After the discharge is joined with the boil-off gas passing through the first heat exchanger 110, the above-described process is repeated.
  • the evaporated gas sent to the propulsion compressor 126 along the return line L3 is compressed by the propulsion compressor 124 and cooled by the propulsion cooler 134. It is sent to the first heat exchanger (110).
  • the boil-off gas sent to the first heat exchanger 110 is first cooled in the first heat exchanger 110, secondly cooled in the second heat exchanger 140, and then expanded by the first pressure reducing device 150.
  • the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170.
  • the gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
  • the ninth valve 201 and the twelfth valve 205 are used. You can also open and operate the system.
  • Figure 6 is a schematic diagram showing a system for treating the boil-off gas in accordance with a fifth embodiment of the present invention.
  • the vessel of the fifth embodiment shown in FIG. 6 does not include the first additional line L6 and recycles the additional compressor 124 and the additional cooler 134 as compared to the vessel of the fourth embodiment shown in FIG. 5.
  • Installed in the line (L5) there is a difference in that the connection position of each line is slightly changed, the following will be mainly described the difference. Detailed description of the same members as those of the ship of the fourth embodiment is omitted.
  • the vessel of the present embodiment like the fourth embodiment, includes the first heat exchanger 110, the first valve 191, the first compressor 120, the first cooler 130, and the second.
  • the first heat exchanger 110 uses the evaporated gas discharged from the storage tank T as the refrigerant and goes to the first heat exchanger 110 along the return line L3. Cool the sent boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the boil-off gas discharged from the storage tank T, and recovers the collected cold heat to the boil-off gas sent to the first heat exchanger 110 along the return line L3. Supply.
  • a fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
  • the first compressor 120 of the present embodiment is installed on the first supply line L1 to compress the evaporated gas discharged from the storage tank T, and the second compressor of the present embodiment ( As in the fourth embodiment, 122 is installed in parallel with the first compressor 120 on the second supply line L2 to compress the boil-off gas discharged from the storage tank T.
  • the first compressor 120 and the second compressor 122 may be compressors of the same performance, and may each be a multistage compressor.
  • the first compressor 120 and the second compressor 122 of the present embodiment can compress the boil-off gas to the pressure required by the fuel demand 180.
  • some of the high pressures are compressed after compressing the boil-off gas in accordance with a required pressure of an engine requiring higher pressure (hereinafter, referred to as a 'high pressure engine'). It can be supplied to the engine, and the other part can be supplied to the low pressure engine after being depressurized by a pressure reducing device installed upstream of the engine requiring a lower pressure (hereinafter referred to as a 'low pressure engine').
  • the boil-off gas is fueled by the first compressor 120 or the second compressor 122. It is compressed to a high pressure higher than the pressure required by the customer 180, and a pressure reducing device is provided upstream of the fuel demand 180 to lower the pressure of the boiled gas compressed to high pressure to the pressure required by the fuel demand 180, and then the fuel demand. 180 may be supplied.
  • the vessel of the present embodiment further includes an eleventh valve 203 which is provided upstream of the fuel demand unit 180 and controls the flow rate and opening and closing of the boil-off gas sent to the fuel demand unit 180. Can be.
  • the vessel of the present embodiment uses the evaporated gas compressed by the second compressor 122 as a refrigerant for additionally cooling the evaporated gas in the second heat exchanger 140, and thus the re-liquefaction efficiency and The amount of liquefaction can be increased.
  • the first cooler 130 of the present embodiment is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 and having risen in pressure and temperature
  • the second cooler 132 of the present embodiment is installed downstream of the second compressor 122 to cool the evaporated gas that passes not only the pressure but also the temperature through the second compressor 122.
  • the propulsion compressor 126 of the present embodiment branches a part of the boil-off gas supplied to the fuel demand 180 along the first supply line L1 and sends it to the first heat exchanger 110. Is installed on the return line (L3), to increase the pressure of the boil-off gas supplied to the first heat exchanger (110) along the return line (L3).
  • the propulsion compressor 126 may compress the boil-off gas to a pressure below the critical point (approximately 55 bar in the case of methane), or may compress it to a pressure above the critical point. If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.
  • the propulsion cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126, similar to the fourth embodiment, and passes through the propulsion compressor 126 to increase not only the pressure but also the temperature. Lower the temperature.
  • the ship of the present embodiment further includes a propulsion compressor 126, like the fourth embodiment, the pressure of the boil-off gas undergoing the reliquefaction process can be increased to increase the amount of reliquefaction and reliquefaction efficiency, and the second compressor ( The use frequency of 122) can be reduced, so that the concept of redundancy can be sufficiently secured, and operating costs can be saved as compared with the case where the propulsion compressor 126 is not installed.
  • the second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 and cooled by the first heat exchanger 110. Cool additionally.
  • the evaporated gas discharged from the storage tank T is additionally cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, so that the temperature is lower.
  • Furnace can be supplied to the first decompression device 150, the re-liquefaction efficiency and the amount of re-liquefaction is increased.
  • the refrigerant pressure reducing device 160 expands the boil-off gas passing through the second heat exchanger 140 and sends it to the second heat exchanger 140 in the same manner as in the fourth embodiment.
  • the additional compressor 124 of the present embodiment compresses the fluid passing through the refrigerant reducing device 160 and the second heat exchanger 140, and is driven by the power generated by the refrigerant reducing device 160 while expanding the fluid.
  • the refrigerant pressure reducing device 160 and the additional compressor 124 of the present embodiment may form a compander 900.
  • the additional compressor 124 may have a smaller capacity than the second compressor 122 and may be a capacity that can be driven by the power produced by the refrigerant pressure reducing device 160.
  • the additional compressor 124 of the present embodiment is not installed on the second supply line L2, but branched from the second supply line L2 to reduce the refrigerant pressure reducing device 160. And the fluid passing through the second heat exchanger 140 is installed on the recirculation line L5 which is sent to the second supply line L2 again.
  • the power generated by the refrigerant pressure reducing device 160 can be utilized, and the additional compressor 124 having a smaller capacity than the second compressor 122 can be added at a low cost. Reliquefaction efficiency and amount of reliquefaction can be raised.
  • the additional cooler 134 of this embodiment is installed downstream of the additional compressor 124 to lower the temperature of the boil-off gas compressed by the additional compressor 124 and whose temperature as well as the pressure is increased.
  • the additional cooler 134 of the present embodiment is installed on the recirculation line L5.
  • the additional compressor 124 and the additional cooler 134 are installed on the recirculation line L5 so that the fluid used as the refrigerant in the second heat exchanger 140 is the closed loop refrigerant cycle of the fourth embodiment.
  • the second compressor 122 and the second cooler 132 that pass through the second compressor 122 and the second cooler 132 are more easily than the fourth embodiment.
  • the boil-off gas may be supplied as fuel to the fuel demand unit 180.
  • the fluid used as the refrigerant in the second heat exchanger 140 along the recirculation line (L5) and the second supply line (L2), the additional compressor 124, the additional cooler 134.
  • the second compressor 122 After passing through the second compressor 122, the second cooler 132, the second heat exchanger 140, the refrigerant pressure reducing device 160, and the second heat exchanger 140 again, the second compressor 122 is sent to the additional compressor 124. Therefore, the same refrigerant cycle as the closed loop refrigerant cycle of the fourth embodiment is circulated.
  • the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in an emergency is compressed by both the additional compressor 124 and the second compressor 122 and then the fuel. Since the second compressor 122 has the same performance as the first compressor 120 because it is supplied to the demand destination 180, the pressure of the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in an emergency. In this case, the pressure may be higher than the pressure of the boil-off gas supplied to the fuel demand 180 along the first supply line L1.
  • the pressure of the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in an emergency is normally supplied to the fuel demand 180 along the first supply line L1.
  • Separate control may be required to equalize the pressure of the boil-off gas, or it may be difficult to utilize the second compressor 122 as redundancy.
  • the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in the emergency is not compressed by the additional compressor 124 but compressed only by the second compressor 122.
  • the fuel demand source (L2) can be easily provided through the second supply line L2 without additional pressure adjustment in an emergency. 180) can be supplied to the boil-off gas.
  • the first pressure reducing device 150 of the present embodiment is installed on the return line L3 and is cooled by the first heat exchanger 110 and the second heat exchanger 140. Inflate.
  • the first pressure reducing device 150 of the present embodiment includes all means capable of expanding and cooling the boil-off gas, and may be an expansion valve such as a Joule-Thomson valve or an expander.
  • the vessel of this embodiment is installed on the return line L3 downstream of the first pressure reducing device 150 and separates the gas-liquid mixture discharged from the first pressure reducing device 150 into gas and liquid.
  • Gas-liquid separator 170 may be included.
  • the vessel of the present embodiment when the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or gaseous-mixed evaporated gas that has passed through the first pressure reducing device 150 is directly sent to the storage tank T.
  • the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first pressure reducing device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase.
  • the liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
  • the vessel of the present embodiment includes the gas-liquid separator 170, like the fourth embodiment, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T) ); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
  • the ship of the present embodiment does not include the first additional line L6, and the second supply line L2 branched from the first supply line L1 is the recirculation line L5. Is joined again with the first supply line L1.
  • the recirculation line L5 branches from the second supply line L2 between the second cooler 132 and the fourth valve 194 instead of the first supply line L1
  • the first supply line ( The second supply line (L2) between the third valve (193) and the second compressor (122) instead of L1 is again joined.
  • the ship of this embodiment unlike the fourth embodiment, does not include the sixth valve 196.
  • the vessel of the present invention does not include the first heat exchanger 110, the evaporated gas discharged from the storage tank (T) is immediately the first compressor 120 or the second compressor (122). ) And the evaporated gas undergoing the reliquefaction process along the return line L3 may be sent to the second heat exchanger 140 immediately after being compressed by the propulsion compressor 126.
  • the fluid circulating along the recirculation line L5 passes through the second heat exchanger 140 firstly, is expanded by the refrigerant pressure reducing device 160, and is then supplied to the second heat exchanger 140 again.
  • the fluid circulating along the recirculation line (L5) of the present invention after being branched from the second supply line (L2) is expanded by the refrigerant pressure reducing device 160 immediately after the second heat exchanger (140) May be sent as). The same applies to the sixth embodiment to be described later.
  • the first to fifth valves, the seventh to ninth valves, the eleventh valves, and the twelfth valves 191, 192, 193, 194, 195, 197, 198, 201, 203, and 205 of the present embodiment operate the system.
  • the situation may be manually adjusted by a person directly and may be automatically adjusted to be opened or closed by a preset value.
  • the refrigerant cycle of the present embodiment is preferably operated in a closed loop, hereinafter, a method of operating the refrigerant cycle of the present embodiment in a closed loop by adjusting a valve will be described.
  • Second compressor 122 When the boil-off gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recirculation line L5, the third valve 193 and the fourth valve 194 are closed to produce the boil-off gas.
  • the storage tank T including the storage tank T of the present embodiment may further include a pipe for introducing nitrogen gas into the refrigerant cycle of the closed loop.
  • the refrigerant cycle When the refrigerant cycle is operated as a closed loop, only the boil-off gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the boil-off gas passing through the first compressor 120 cannot be introduced into the refrigerant cycle. It is supplied to the fuel demand 180, or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction or the amount of boil-off gas required by the fuel demand unit 180, the boil-off gas of a constant flow rate is circulated to the refrigerant of the second heat exchanger 140.
  • the refrigerant cycle of the present embodiment When the refrigerant cycle of the present embodiment is operated in a closed loop, it is easier to control the flow rate of each of the evaporated gas that is undergoing the reliquefaction process and the evaporated gas used as the refrigerant compared to the case of operating the closed loop or the independent open loop. There is this.
  • the boil-off gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, and a part of the fuel demand unit 180 is removed. The remaining part is subjected to the reliquefaction process along the return line (L3).
  • the evaporated gas passed through the first heat exchanger 110 after being discharged from the storage tank T may be about 1 bar, and about 1 bar of the evaporated gas may be compressed by the first compressor 120 so that approximately 17 bar may be Can be.
  • the pressure of the boil-off gas compressed by the first compressor 120 may vary depending on the reliquefaction performance required by the system and the operating situation of the system.
  • the boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled.
  • the boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
  • the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170.
  • the gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
  • the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the second compressor 122 and by the second cooler 132. Cooled and sent to the second heat exchanger 140 along the recycle line (L5). After passing through the additional compressor 124 and the second compressor 122, the boil-off gas sent to the second heat exchanger 140 is first heat-exchanged by the second heat exchanger 140, and then cooled. It is sent to the secondary expansion and cooled.
  • the boil-off gas compressed by the additional compressor 124 may be about 2 bar, and the boil-off gas of about 2 bar may be compressed by the second compressor 122 to be about 32 bar.
  • the pressure of the boil-off gas compressed by the additional compressor 124 and the pressure of the boil-off gas compressed by the second compressor 122 may vary depending on the reliquefaction performance required by the system and the operating conditions of the system.
  • the evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
  • the first valve 191, the second valve 192, and the ninth valve are damaged. 201 and the 12th valve 205 are closed, the 3rd valve 193 and the 4th valve 194 are opened, the evaporation which passed through the 1st heat exchanger 110 after discharge
  • the gas is supplied to the fuel demand 180 through the third valve 193, the second compressor 122, the second cooler 132, and the fourth valve 194.
  • FIG. 7 is a configuration diagram schematically showing a boil-off gas treatment system according to a sixth embodiment of the present invention.
  • the ship of the sixth embodiment shown in FIG. 7 has a second additional line L11 and a thirteenth valve 206 installed on the second additional line L11, compared to the ship of the fifth embodiment shown in FIG. 6.
  • the fifteenth valve 207 installed on the third additional line L12, the third additional line L12, the fourth additional line L13, and the fifteenth valve installed on the fourth additional line L13. Differences exist in that they further include (208), and the following description will focus on the differences. Detailed description of the same members as those of the ship of the fifth embodiment described above will be omitted.
  • the vessel of the present embodiment like the fifth embodiment, includes the first heat exchanger 110, the first valve 191, the first compressor 120, the first cooler 130, and the second.
  • the first heat exchanger 110 of the present embodiment uses the evaporated gas discharged from the storage tank T as the refrigerant, and then returns to the first heat exchanger 110 along the return line L3. Cool the sent boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the boil-off gas discharged from the storage tank T, and recovers the collected cold heat to the boil-off gas sent to the first heat exchanger 110 along the return line L3. Supply.
  • a fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
  • the first compressor 120 of the present embodiment is installed on the first supply line L1 to compress the boil-off gas discharged from the storage tank T, and the second compressor of the present embodiment ( As in the fifth embodiment, 122 is installed in parallel with the first compressor 120 on the second supply line L2 to compress the boil-off gas discharged from the storage tank T.
  • the first compressor 120 and the second compressor 122 may be compressors of the same performance, and may each be a multistage compressor.
  • the first compressor 120 and the second compressor 122 of the present embodiment can compress the boil-off gas to the pressure required by the fuel demand unit 180.
  • the fuel demand unit 180 includes several types of engines, some of the high pressures are compressed after compressing the boil-off gas in accordance with a required pressure of an engine requiring higher pressure (hereinafter, referred to as a 'high pressure engine'). It can be supplied to the engine, and the other part can be supplied to the low pressure engine after being depressurized by a pressure reducing device installed upstream of the engine requiring a lower pressure (hereinafter referred to as a 'low pressure engine').
  • the boil-off gas is fueled by the first compressor 120 or the second compressor 122. It is compressed to a high pressure higher than the pressure required by the customer 180, and a pressure reducing device is provided upstream of the fuel demand 180 to lower the pressure of the boiled gas compressed to high pressure to the pressure required by the fuel demand 180, and then the fuel demand. 180 may be supplied.
  • the ship of this embodiment further includes an eleventh valve 203 which is provided upstream of the fuel demand unit 180 and regulates the flow rate and opening / closing of the boil-off gas sent to the fuel demand unit 180. Can be.
  • the first cooler 130 of the present embodiment is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 and having risen in pressure and temperature
  • the second cooler 132 of the present embodiment is installed downstream of the second compressor 122 to cool the evaporated gas that passes not only the pressure but also the temperature through the second compressor 122.
  • the propulsion compressor 126 of the present embodiment is installed on the return line L3 to increase the pressure of the boil-off gas supplied to the first heat exchanger 110 along the return line L3. .
  • the propulsion compressor 126 may compress the boil-off gas to a pressure below the critical point (approximately 55 bar in the case of methane), or may compress it to a pressure above the critical point. If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.
  • the propulsion cooler 136 of the present embodiment is installed on the return line L3 downstream of the propulsion compressor 126 and passes through the propulsion compressor 126 to increase not only the pressure but also the temperature. Lower the temperature.
  • the ship of the present embodiment further includes a propulsion compressor 126, similar to the fifth embodiment, the pressure of the boil-off gas undergoing the reliquefaction process can be increased to increase the amount of reliquefaction and reliquefaction, and the concept of redundancy It can be secured enough and the operating cost can be saved.
  • the second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 and cooled by the first heat exchanger 110. Cool additionally.
  • the boil-off gas discharged from the storage tank T is additionally cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, so that the temperature is lower. Furnace can be supplied to the first decompression device 150, the re-liquefaction efficiency and the amount of re-liquefaction is increased.
  • the refrigerant pressure reducing device 160 expands the evaporated gas passing through the second heat exchanger 140 and sends it to the second heat exchanger 140 in the same manner as in the fifth embodiment.
  • the additional compressor 124 of the present embodiment is installed on the recirculation line L5 to compress the fluid passing through the refrigerant pressure reducing device 160 and the second heat exchanger 140.
  • the additional compressor 124 of the present embodiment is driven by the power generated by the refrigerant pressure reducing device 160 while expanding the fluid, and the refrigerant pressure reducing device 160 and the additional compressor 124 are used. May form a compander 900.
  • the additional compressor 124 may have a smaller capacity than the second compressor 122 and may be a capacity that can be driven by the power produced by the refrigerant pressure reducing device 160.
  • the additional pressure compressor 124 having a smaller capacity than that of the first compressor 120 or the second compressor 122 can be utilized, using the power generated by the refrigerant pressure reducing device 160. ) Can increase reliquefaction efficiency and reliquefaction amount at low cost.
  • the additional cooler 134 of this embodiment is installed downstream of the additional compressor 124 on the recirculation line L5, and is compressed by the additional compressor 124, and the pressure as well as the temperature is increased. Lower the temperature.
  • the additional compressor 124 and the additional cooler 134 are installed on the recirculation line L5 so that the fluid used as the refrigerant in the second heat exchanger 140 is formed. While allowing the first compressor 120 or the first cooler 130 to fail while circulating the same path as the closed loop refrigerant cycle of the fourth embodiment, the second compressor 122 and the second compressor are easier than the fourth embodiment.
  • the boil-off gas passing through the cooler 132 may be supplied as fuel to the fuel demand unit 180.
  • the second compressor 122 or the second cooler 132 fails while the system is operated to supply the boil-off gas compressed by the second compressor 122 to the fuel demand 180.
  • the boil-off gas passed through the first compressor 120 and the first cooler 130 may be supplied as fuel to the fuel demand unit 180 more easily than the fourth embodiment.
  • the first pressure reducing device 150 of the present embodiment is installed on the return line L3 and is the boil-off gas cooled by the first heat exchanger 110 and the second heat exchanger 140. Inflate.
  • the first pressure reducing device 150 of the present embodiment includes all means capable of expanding and cooling the boil-off gas, and may be an expansion valve such as a Joule-Thomson valve or an expander.
  • the vessel of this embodiment is installed on the return line L3 downstream of the first pressure reducing device 150 and separates the gas-liquid mixture discharged from the first pressure reducing device 150 into gas and liquid.
  • Gas-liquid separator 170 may be included.
  • the vessel of the present embodiment when the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or gaseous-mixed evaporated gas that has passed through the first pressure reducing device 150 is directly sent to the storage tank T.
  • the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first pressure reducing device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase.
  • the liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
  • the ship of the present embodiment includes the gas-liquid separator 170, like the fifth embodiment, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T) ); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
  • the ship of the present embodiment does not include the first additional line L6, and the second supply line L2 branched from the first supply line L1 is the first supply line ( L1) is joined again, and after the recirculation line L5 branches from the second supply line L2 between the second cooler 132 and the fourth valve 194, the third valve 193 and the second It is again joined with the second supply line L2 between the compressors 122.
  • the ship of this embodiment unlike the fifth embodiment, the second additional line (L11); A thirteenth valve 206 installed on the second additional line L11; Third additional line L12; A fourteenth valve 207 installed on the third additional line L12; A fourth additional line L13; And a fifteenth valve 208 installed on the fourth additional line L13.
  • the second additional line L11 of the present embodiment is branched from the recirculation line L5 between the additional cooler 134 and the ninth valve 201 and is formed between the first valve 191 and the first compressor 120. 1 is joined to the supply line (L1).
  • the third additional line L12 of the present embodiment is branched from the first supply line L1 between the first cooler 130 and the second valve 192 to be the twelfth valve 205 and the second heat exchanger 140. Is joined to the recirculation line L5.
  • the fourth additional line L13 of the present embodiment branches from the second supply line L2 between the second cooler 132 and the fourth valve 194 to between the fifth valve 195 and the propulsion compressor 126. Is joined to the return line L3.
  • both the first compressor 120 and the second compressor 122 the use of compressing the boil-off gas supplied to the refrigerant cycle; Or it can be used to select; for the purpose of compressing the boil-off gas supplied to the fuel demand (180).
  • the boil-off gas branched from the first supply line L1 but also the boil-off gas branched from the second supply line L2 is selectively returned to the line L3.
  • the boil-off gas which is normally compressed by the first compressor 120 is sent to the fuel demand 180 or undergoes a reliquefaction process along the return line L3, and the second compressor 122
  • the compressed boil-off gas circulates through the refrigerant cycle, and the use of the first compressor 120 and the second compressor 122 cannot be changed.
  • one of the first compressor 120 and the second compressor 122 is selected to supply the boil-off gas to the fuel demand 180 or the return line L3, and the fuel demand 180
  • the refrigerant cycle can be circulated with the boil-off gas compressed by another compressor which does not supply boil-off gas to Therefore, according to this embodiment, there is an advantage that the operation of the system is free compared with the fifth embodiment.
  • 207 and 208 may be manually adjusted by a person directly determining a system operating situation, or may be automatically adjusted to open and close by a preset value.
  • the refrigerant cycle of the present embodiment is preferably operated in a closed loop, hereinafter, a method of operating the refrigerant cycle of the present embodiment in a closed loop by adjusting a valve will be described.
  • the refrigerant cycle of the ship of the present embodiment is operated as a closed loop, and the evaporated gas compressed by the first compressor 120 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122.
  • the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the fifth valve 195, the ninth valve 201, and The twelfth valve 205 is opened, and the thirteenth valve 206, the fourteenth valve 207, and the fifteenth valve 208 drive the system in the closed state.
  • Second compressor 122 When the boil-off gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recirculation line L5, the third valve 193 and the fourth valve 194 are closed to produce the boil-off gas.
  • the storage tank T including the storage tank T of the present embodiment may further include a pipe for introducing nitrogen gas into the refrigerant cycle of the closed loop.
  • the refrigerant cycle When the refrigerant cycle is operated as a closed loop, only the boil-off gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the boil-off gas passing through the first compressor 120 cannot be introduced into the refrigerant cycle. It is supplied to the fuel demand 180, or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction or the amount of boil-off gas required by the fuel demand unit 180, the boil-off gas of a constant flow rate is circulated to the refrigerant of the second heat exchanger 140.
  • the refrigerant cycle of the present embodiment When the refrigerant cycle of the present embodiment is operated in a closed loop, it is easier to control the flow rate of each of the evaporated gas that is undergoing the reliquefaction process and the evaporated gas used as the refrigerant compared to the case of operating the closed loop or the independent open loop. There is this.
  • the refrigerant cycle of the ship of the present embodiment is operated as a closed loop, and the evaporated gas compressed by the first compressor 120 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122.
  • the flow of the boil-off gas will be described.
  • the boil-off gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, and a part of the fuel demand unit 180 is removed. The remaining part is subjected to the reliquefaction process along the return line (L3).
  • the evaporated gas passed through the first heat exchanger 110 after being discharged from the storage tank T may be about 1 bar, and about 1 bar of the evaporated gas may be compressed by the first compressor 120 so that approximately 17 bar may be Can be.
  • the pressure of the boil-off gas compressed by the first compressor 120 may vary depending on the reliquefaction performance required by the system and the operating situation of the system.
  • the boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled.
  • the boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
  • the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170.
  • the gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
  • the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the second compressor 122 and by the second cooler 132. Cooled and sent to the second heat exchanger 140 along the recycle line (L5). After passing through the additional compressor 124 and the second compressor 122, the boil-off gas sent to the second heat exchanger 140 is first heat-exchanged by the second heat exchanger 140, and then cooled. It is sent to the secondary expansion and cooled.
  • the boil-off gas compressed by the additional compressor 124 may be about 2 bar, and the boil-off gas of about 2 bar may be compressed by the second compressor 122 to be about 32 bar.
  • the pressure of the boil-off gas compressed by the additional compressor 124 and the pressure of the boil-off gas compressed by the second compressor 122 may vary depending on the reliquefaction performance required by the system and the operating conditions of the system.
  • the evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
  • the refrigerant cycle of the ship of the present embodiment is operated as a closed loop, and the evaporated gas compressed by the first compressor 120 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122. If the first compressor 120 or the first cooler 130 breaks down while circulating, the first valve 191, the second valve 192, the fifth valve 195, and the ninth valve 201 are damaged. And the twelfth valve 205 is closed, the third valve 193 and the fourth valve 194 are opened, and the boil-off gas passed through the first heat exchanger 110 after being discharged from the storage tank T, The third valve 193, the second compressor 122, the second cooler 132, and the fourth valve 194 may be supplied to the fuel demand 180.
  • the refrigerant cycle of the ship of this embodiment is operated in a closed loop, and the evaporated gas compressed by the second compressor 122 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the boiled gas compressed by the first compressor 120.
  • the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the thirteenth valve 206, the fourteenth valve 207, and The fifteenth valve 208 is opened, and the fifth valve 195, the ninth valve 201, and the twelfth valve 205 drive the system in a closed state.
  • the boil-off gas compressed by the first compressor 120 after being discharged from the storage tank T is supplied to the recirculation line L5 along the third additional line L12, the first valve 191 and the second By closing the valve 192, the boil-off gas is discharged into the first compressor 120, the first cooler 130, the fourteenth valve 207, the second heat exchanger 140, the refrigerant pressure reducing device 160, and the second heat exchanger.
  • a closed loop refrigerant cycle is formed that circulates the air 140, the additional compressor 124, the additional cooler 134, and the thirteenth valve 206.
  • the refrigerant cycle of the ship of this embodiment is operated in a closed loop, and the evaporated gas compressed by the second compressor 122 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the boiled gas compressed by the first compressor 120.
  • the flow of the boil-off gas will be described.
  • the boil-off gas discharged from the storage tank T passes through the first heat exchanger 110, is compressed by the second compressor 122, and is cooled by the second cooler 132, and a part of the fuel demand 180 is removed. And the remaining part is passed through the fifteenth valve 208 to the reliquefaction process along the return line (L3).
  • the evaporated gas passed from the storage tank T and passed through the first heat exchanger 110 may be about 1 bar, and about 1 bar of the boil-off gas may be compressed by the second compressor 122 so that approximately 17 bar Can be.
  • the pressure of the boil-off gas compressed by the second compressor 122 may vary depending on the reliquefaction performance required by the system and the operating situation of the system.
  • the boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled.
  • the boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
  • the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170.
  • the gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
  • the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the first compressor 120 and by the first cooler 130.
  • the fourteenth valve 207 is sent to the second heat exchanger 140 along the recirculation line L5.
  • the evaporated gas sent to the second heat exchanger 140 is first heat exchanged and cooled in the second heat exchanger 140, and then the refrigerant pressure reducing device 160 is applied. It is sent to the secondary expansion and cooled.
  • the boil-off gas compressed by the additional compressor 124 may be about 2 bar, and the boil-off gas of about 2 bar may be compressed by the first compressor 120 to be about 32 bar.
  • the pressure of the boil-off gas compressed by the additional compressor 124 and the pressure of the boil-off gas compressed by the first compressor 120 may vary depending on the reliquefaction performance required by the system and the operating conditions of the system.
  • the evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the first compressor 120 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
  • the refrigerant cycle of the ship of this embodiment is operated in a closed loop, and the evaporated gas compressed by the second compressor 122 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the boiled gas compressed by the first compressor 120. If the second compressor 122 or the second cooler 132 fails during the circulation, the third valve 193, the fourth valve 194, the thirteenth valve 206, and the fourteenth valve 207 are damaged. , And the fifteenth valve 208 is closed, the first valve 191 and the second valve 192 are opened, and the evaporated gas passed through the first heat exchanger 110 after being discharged from the storage tank T, The first valve 191, the first compressor 120, the first cooler 130, and the second valve 192 are supplied to the fuel demand 180.

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Abstract

Disclosed is a ship comprising a liquefied gas storage tank. A ship comprises: a first compressor which can compress one or more parts of a boil-off gas discharged from a storage tank; a second compressor which is for compressing the other part of the boil-off gas discharged from the storage tank; a propulsion compressor which is for compressing one part of the boil-off gas that has been compressed by means of the first compressor and/or the second compressor; a first heat exchanger which is for heat exchanging the boil-off gas compressed by means of the propulsion compressor and the boil-off gas discharged from the storage tank; a refrigerant decompressing device which is for expanding the other part of the boil-off gas that has been compressed by means of the first compressor and/or the second compressor; a second heat exchanger which is for cooling, by means of a fluid expanded by means of the refrigerant decompressing device as a refrigerant, the boil-off gas that has been compressed by means of the propulsion compressor and heat exchanged by means of the first heat exchanger; an additional compressor which is for compressing the refrigerant that has passed the refrigerant decompressing device and second heat exchanger; and a first decompressing device which is for expanding the fluid that has been compressed by means of the propulsion compressor and then cooled by means of the first heat exchanger and second heat exchanger, wherein the additional compressor is driven by means of power generated from the expanding of the fluid by means of the refrigerant decompressing device.

Description

선박Ship
본 발명은 선박에 관한 것으로서, 더욱 상세하게는 저장탱크 내부에서 생성되는 증발가스 중 엔진의 연료로 사용되고 남은 증발가스를 재액화시키는 시스템을 포함하는 선박에 관한 것이다.The present invention relates to a ship, and more particularly, to a ship including a system for re-liquefying the remaining boil-off gas used as the fuel of the engine in the boil-off gas generated inside the storage tank.
근래, 액화천연가스(Liquefied Natural Gas, LNG) 등의 액화가스의 소비량이 전 세계적으로 급증하고 있는 추세이다. 가스를 저온에서 액화시킨 액화가스는 가스에 비해 부피가 매우 작아지므로 저장 및 이송 효율을 높일 수 있는 장점이 있다. 또한, 액화천연가스를 비롯한 액화가스는 액화공정 중에 대기오염 물질을 제거하거나 줄일 수 있어, 연소시 대기오염 물질 배출이 적은 친환경 연료로도 볼 수 있다. Recently, the consumption of liquefied gas such as liquefied natural gas (Liquefied Natural Gas, LNG) is increasing worldwide. Liquefied gas liquefied gas at low temperature has the advantage that the storage and transport efficiency can be improved because the volume is very small compared to the gas. In addition, liquefied gas, including liquefied natural gas can remove or reduce air pollutants during the liquefaction process, it can be seen as an environmentally friendly fuel with less emissions of air pollutants during combustion.
액화천연가스는 메탄(methane)을 주성분으로 하는 천연가스를 약 -162℃로 냉각해서 액화시킴으로써 얻을 수 있는 무색투명한 액체로서, 천연가스와 비교해 약 1/600 정도의 부피를 가진다. 따라서, 천연가스를 액화시켜 이송할 경우 매우 효율적으로 이송할 수 있게 된다.Liquefied natural gas is a colorless and transparent liquid obtained by liquefying natural gas containing methane as a main component at about -162 ℃, and has a volume of about 1/600 compared with natural gas. Therefore, when liquefied and transported natural gas can be transported very efficiently.
그러나 천연가스의 액화 온도는 상압 -162 ℃의 극저온이므로, 액화천연가스는 온도변화에 민감하여 쉽게 증발된다. 이로 인해 액화천연가스를 저장하는 저장탱크에는 단열처리를 하지만, 외부의 열이 저장탱크에 지속적으로 전달되므로 액화천연가스 수송과정에서 저장탱크 내에서는 지속적으로 액화천연가스가 자연 기화되면서 증발가스(Boil-Off Gas, BOG)가 발생한다. 이는 에탄 등 다른 저온 액화가스의 경우에도 마찬가지이다.However, since the liquefaction temperature of natural gas is a cryogenic temperature of -162 ℃, liquefied natural gas is easily evaporated because it is sensitive to temperature changes. As a result, the storage tank storing the liquefied natural gas is insulated. However, since the external heat is continuously transferred to the storage tank, the natural gas is continuously vaporized in the storage tank during the transport of the liquefied natural gas. -Off Gas, BOG) occurs. The same applies to other low temperature liquefied gases such as ethane.
증발가스는 일종의 손실로서 수송효율에 있어서 중요한 문제이다. 또한, 저장탱크 내에 증발가스가 축적되면 탱크 내압이 과도하게 상승할 수 있어, 심하면 탱크가 파손될 위험도 있다. 따라서, 저장탱크 내에서 발생하는 증발가스를 처리하기 위한 다양한 방법이 연구되는데, 최근에는 증발가스의 처리를 위해, 증발가스를 재액화하여 저장탱크로 복귀시키는 방법, 증발가스를 선박의 엔진 등 연료소비처의 에너지원으로 사용하는 방법 등이 사용되고 있다.Boil-off gas is a kind of loss and is an important problem in transportation efficiency. In addition, when boil-off gas is accumulated in the storage tank, the internal pressure of the tank may be excessively increased, and there is also a risk that the tank may be damaged. Accordingly, various methods for treating the boil-off gas generated in the storage tank have been studied. In recent years, for the treatment of the boil-off gas, a method of re-liquefying the boil-off gas to return to the storage tank, and returning the boil-off gas to the fuel of a ship engine The method used as an energy source of a consumer is used.
증발가스를 재액화하기 위한 방법으로는 별도의 냉매를 이용한 냉동 사이클을 구비하여 증발가스를 냉매와 열교환하여 재액화하는 방법, 및 별도의 냉매가 없이 증발가스 자체를 냉매로 하여 재액화하는 방법 등이 있다. 특히, 후자의 방법을 채용한 시스템을 부분 재액화 시스템(Partial Re-liquefaction System, PRS)이라고 한다.As a method for reliquefaction of the boil-off gas, a refrigeration cycle using a separate refrigerant is used to re-liquefy the boil-off gas by exchanging the boil-off gas with the refrigerant, and a method of re-liquefying the boil-off gas itself as a refrigerant without a separate refrigerant. There is this. In particular, a system employing the latter method is called a Partial Re-liquefaction System (PRS).
한편, 일반적으로 선박에 사용되는 엔진 중 천연가스를 연료로 사용할 수 있는 엔진으로 DFDE 및 ME-GI 엔진 등의 가스연료엔진이 있다.On the other hand, among the engines generally used in ships as a fuel that can use natural gas as a fuel gas engine such as DFDE and ME-GI engine.
DFDE은, 4행정으로 구성되며, 비교적 저압인 6.5bar 정도의 압력을 가지는 천연가스를 연소공기 입구에 주입하여, 피스톤이 올라가면서 압축을 시키는 오토 사이클(Otto Cycle)을 채택하고 있다.DFDE is composed of four strokes and adopts the Otto Cycle, which injects natural gas with a relatively low pressure of 6.5 bar into the combustion air inlet and compresses the piston as it rises.
ME-GI 엔진은, 2행정으로 구성되며, 300bar 부근의 고압 천연가스를 피스톤의 상사점 부근에서 연소실에 직접 분사하는 디젤 사이클(Diesel Cycle)을 채택하고 있다. 최근에는 연료 효율 및 추진 효율이 더 좋은 ME-GI 엔진에 대한 관심이 커지고 있는 추세이다.The ME-GI engine is composed of two strokes and employs a diesel cycle that directly injects high pressure natural gas near 300 bar into the combustion chamber near the top dead center of the piston. Recently, there is a growing interest in ME-GI engines with better fuel efficiency and propulsion efficiency.
본 발명은 기존의 부분 재액화 시스템에 비해 향상된 증발가스 재액화 성능을 발휘할 수 있는 시스템을 포함하는 선박을 제공하는 것을 목적으로 한다.It is an object of the present invention to provide a vessel comprising a system capable of exhibiting improved boil-off gas reliquefaction performance as compared to existing partial reliquefaction systems.
상기 목적을 달성하기 위한 본 발명의 일 측면에 따르면, 액화가스 저장탱크를 포함하는 선박에 있어서, 상기 저장탱크로부터 배출되는 증발가스의 적어도 일부를 압축시킬 수 있는 제1 압축기; 상기 저장탱크로부터 배출되는 증발가스의 다른 일부를 압축시키는 제2 압축기; 상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 일부를 압축시키는 추진압축기; 상기 추진압축기에 의해 압축된 증발가스와 상기 저장탱크로부터 배출되는 증발가스를 열교환시키는 제1 열교환기; 상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 다른 일부를 팽창시키는 냉매감압장치; 상기 냉매감압장치에 의해 팽창된 유체를 냉매로하여 상기 추진압축기에 의해 압축되고 상기 제1 열교환기에서 열교환된 증발가스를 냉각시키는 제2 열교환기; 상기 냉매감압장치 및 상기 제2 열교환기를 통과한 냉매를 압축시키는 추가압축기; 및 상기 추진압축기에 의해 압축된 후 상기 제1 열교환기 및 상기 제2 열교환기에서 냉각된 유체를 팽창시키는 제1 감압장치;를 포함하고, 상기 추가압축기는 상기 냉매감압장치가 유체를 팽창시키면서 생산하는 동력에 의해 구동되는, 선박이 제공된다.According to an aspect of the present invention for achieving the above object, a vessel comprising a liquefied gas storage tank, the first compressor capable of compressing at least a portion of the boil-off gas discharged from the storage tank; A second compressor for compressing another part of the boil-off gas discharged from the storage tank; A propelling compressor for compressing a part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A first heat exchanger configured to heat exchange the boil-off gas compressed by the propulsion compressor with the boil-off gas discharged from the storage tank; A refrigerant reducing device for expanding another part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger configured to cool the boil-off gas compressed by the propulsion compressor and heat-exchanged in the first heat exchanger by using the fluid expanded by the refrigerant reduction device as a refrigerant; An additional compressor for compressing the refrigerant having passed through the refrigerant reducing device and the second heat exchanger; And a first pressure reducing device that expands the fluid cooled in the first heat exchanger and the second heat exchanger after being compressed by the propulsion compressor, wherein the additional compressor is produced while the refrigerant pressure reducing device expands the fluid. A ship is provided, which is driven by power.
상기 추진압축기는 상기 제1 압축기에 의해 압축된 증발가스만을 압축시키되, 상기 냉매감압장치는 상기 제2 압축기에 의해 압축된 증발가스만을 팽창시킬 수 있다.The propulsion compressor may compress only the boil-off gas compressed by the first compressor, and the refrigerant reducing device may expand only the boil-off gas compressed by the second compressor.
상기 추가압축기는 상기 제2 열교환기를 통과한 냉매를 압축하여 상기 제2 압축기로 보낼 수 있다.The additional compressor may compress the refrigerant passing through the second heat exchanger to be sent to the second compressor.
상기 추가압축기는 상기 제2 열교환기를 통과한 냉매를 압축하여 상기 제1 압축기 및 상기 제2 압축기로 보낼 수 있다.The additional compressor may compress the refrigerant passing through the second heat exchanger and send the refrigerant to the first compressor and the second compressor.
상기 추진압축기는 상기 제1 압축기와 상기 제2 압축기에 의해 압축된 증발가스 중 일부를 압축시키고, 상기 냉매감압장치는 상기 제1 압축기와 상기 제2 압축기에 의해 압축된 증발가스 중 다른 일부를 팽창시킬 수 있다.The propulsion compressor compresses a part of the boil-off gas compressed by the first compressor and the second compressor, and the refrigerant reducing device expands another part of the boil-off gas compressed by the first compressor and the second compressor. You can.
상기 제2 열교환기로 보내진 증발가스는, 상기 제2 열교환기를 1차로 통과하고 상기 냉매감압장치에 의해 팽창된 후 다시 상기 제2 열교환기로 보내지고, 상기 냉매감압장치에 의해 팽창된 후 상기 냉매감압장치에서 냉매로 사용되는 유체는, 상기 냉매감압장치를 통과하기 전에 상기 제2 열교환기로 보내진 유체; 및 상기 추진압축기에 의해 압축된 후 상기 제1 열교환기에 의해 냉각된 증발가스;를 모두 냉각시킬 수 있다.The boil-off gas sent to the second heat exchanger passes through the second heat exchanger firstly and is expanded by the refrigerant pressure reducing device, and then is sent to the second heat exchanger again, and is expanded by the refrigerant pressure reducing device and then the refrigerant pressure reducing device. Fluid used as a refrigerant in the fluid is sent to the second heat exchanger before passing through the refrigerant pressure reduction device; And the boil-off gas cooled by the first heat exchanger after being compressed by the propulsion compressor.
상기 선박은, 상기 추진압축기, 상기 제1 열교환기, 상기 제2 열교환기 및 상기 제1 감압장치를 통과하며 일부 재액화된 액화가스와, 기체상태로 남아있는 증발가스를 분리하는 기액분리기를 더 포함할 수 있고, 상기 기액분리기에 의해 분리된 액화가스는 상기 저장탱크로 보내지고, 상기 기액분리기에 의해 분리된 증발가스는 상기 제1 열교환기로 보내질 수 있다.The vessel further comprises a gas-liquid separator separating the partially reliquefied liquefied gas and the evaporated gas remaining in the gaseous state through the propulsion compressor, the first heat exchanger, the second heat exchanger, and the first decompression device. It may include, the liquefied gas separated by the gas-liquid separator is sent to the storage tank, the boil-off gas separated by the gas-liquid separator may be sent to the first heat exchanger.
상기 추진압축기로 보내지는 증발가스의 일부는, 상기 추진압축기 상류에서 분기되어 연료수요처로 공급될 수 있다.A portion of the boil-off gas sent to the propulsion compressor may be branched upstream of the propulsion compressor and supplied to the fuel demand.
상기 선박은, 증발가스가 상기 제2 압축기, 상기 냉매감압장치, 상기 제2 열교환기, 및 상기 추가압축기를 순환하는 폐루프 냉매 사이클을 형성할 수 있다.The vessel may form a closed loop refrigerant cycle in which boil-off gas circulates the second compressor, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor.
상기 목적을 달성하기 위한 본 발명의 다른 측면에 따르면, 액화가스 저장탱크를 포함하는 선박에 있어서, 상기 저장탱크로부터 배출되는 증발가스의 적어도 일부를 압축시킬 수 있는 제1 압축기; 상기 저장탱크로부터 배출되는 증발가스의 다른 일부를 압축시키는 제2 압축기; 상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 일부를 압축시키는 추진압축기; 상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 다른 일부를 팽창시키는 냉매감압장치; 상기 냉매감압장치에 의해 팽창된 유체를 냉매로하여 상기 추진압축기에 의해 압축된 증발가스를 냉각시키는 제2 열교환기; 상기 냉매감압장치 및 상기 제2 열교환기를 통과한 냉매를 압축시키는 추가압축기; 및 상기 추진압축기에 의해 압축된 후 상기 제2 열교환기에서 냉각된 유체를 팽창시키는 제1 감압장치;를 포함하고, 상기 추가압축기는 상기 냉매감압장치가 유체를 팽창시키면서 생산하는 동력에 의해 구동되는, 선박이 제공된다.According to another aspect of the present invention for achieving the above object, a vessel comprising a liquefied gas storage tank, comprising: a first compressor capable of compressing at least a portion of the boil-off gas discharged from the storage tank; A second compressor for compressing another part of the boil-off gas discharged from the storage tank; A propelling compressor for compressing a part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A refrigerant reducing device for expanding another part of the boil-off gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger configured to cool the boil-off gas compressed by the propulsion compressor using the fluid expanded by the refrigerant reduction device as a refrigerant; An additional compressor for compressing the refrigerant having passed through the refrigerant reducing device and the second heat exchanger; And a first decompression device configured to expand the fluid cooled in the second heat exchanger after being compressed by the propulsion compressor, wherein the additional compressor is driven by power generated by the refrigerant decompression device while expanding the fluid. Ships are provided.
상기 목적을 달성하기 위한 본 발명의 또 다른 측면에 따르면, 액화가스를 저장하는 저장탱크를 포함하는 선박의 증발가스 처리 시스템에 있어서, 상기 저장탱크로부터 배출되는 증발가스의 일부를 제1 압축기에 의해 압축시킨 후 연료수요처로 보내는 제1 공급라인; 상기 제1 공급라인으로부터 분기되어, 상기 저장탱크로부터 배출되는 증발가스의 다른 일부를 제2 압축기에 의해 압축시키는 제2 공급라인; 상기 제1 공급라인으로부터 분기되어, 압축된 증발가스를 추진압축기에 의해 추가적으로 압축시킨 후 제1 열교환기, 제2 열교환기, 및 제1 감압장치를 통과시켜 재액화시키는 복귀라인; 상기 제2 열교환기 및 냉매감압장치를 통과하며 냉각된 증발가스를 다시 상기 제2 열교환기로 보내 냉매로 사용하도록 하는 재순환라인; 및 상기 제2 압축기 상류에 설치되어 증발가스를 압축시키는 추가압축기;를 포함하고, 상기 추가압축기는 상기 냉매감압장치가 유체를 팽창시키면서 생산하는 동력에 의해 구동되고, 상기 제1 열교환기는, 상기 저장탱크로부터 배출된 증발가스를 냉매로 하여, 상기 추진압축기에 의해 압축된 후 상기 복귀라인을 따라 공급되는 증발가스를 열교환시켜 냉각시키고, 상기 제2 열교환기는, 상기 냉매감압장치를 통과한 증발가스를 냉매로 하여, 상기 재순환라인을 따라 공급되는 증발가스; 및 상기 복귀라인을 따라 공급되는 증발가스;를 둘 다 열교환시켜 냉각시키는, 선박의 증발가스 처리 시스템이 제공된다.According to another aspect of the present invention for achieving the above object, in the ship boil-off gas treatment system including a storage tank for storing liquefied gas, a portion of the boil-off gas discharged from the storage tank by the first compressor A first supply line which is compressed and then sent to the fuel demand; A second supply line branched from the first supply line and compressing another portion of the boil-off gas discharged from the storage tank by a second compressor; A return line branched from the first supply line to further compress the compressed boil-off gas by means of a propulsion compressor and then reliquefy by passing through a first heat exchanger, a second heat exchanger, and a first pressure reducing device; A recirculation line passing through the second heat exchanger and the refrigerant pressure reducing device and sending the cooled boil-off gas back to the second heat exchanger for use as a refrigerant; And an additional compressor installed upstream of the second compressor to compress the boil-off gas, wherein the additional compressor is driven by a power produced by the refrigerant reducing device while expanding the fluid, and the first heat exchanger is configured to store the The evaporated gas discharged from the tank is used as a refrigerant, and is cooled by heat-exchanging the evaporated gas supplied through the return line after being compressed by the propulsion compressor, and the second heat exchanger receives the evaporated gas passed through the refrigerant reducing device. An evaporation gas supplied along the recirculation line as a refrigerant; And an evaporation gas supplied along the return line.
상기 추가압축기는 상기 제2 공급라인 상에 설치될 수 있다.The additional compressor may be installed on the second supply line.
상기 추가압축기는 상기 냉매감압장치 및 상기 제2 열교환기 하류의 상기 재순환라인 상에 설치될 수 있다.The additional compressor may be installed on the recirculation line downstream of the refrigerant reducing device and the second heat exchanger.
상기 선박의 증발가스 처리 시스템은, 상기 냉매감압장치 및 상기 제2 열교환기 하류의 재순환라인과, 상기 제2 압축기 상류의 제2 공급라인 사이를 연결하는 제1 추가라인을 포함할 수 있다.The evaporative gas treatment system of the vessel may include a first additional line connecting between the refrigerant reducing device and the second heat exchanger downstream of the second heat exchanger and a second supply line upstream of the second compressor.
상기 선박의 증발가스 처리 시스템은, 증발가스가 상기 추가압축기, 상기 제2 압축기, 상기 제2 열교환기, 상기 냉매감압장치, 및 다시 상기 제2 열교환기를 통과한 후, 상기 제1 추가라인을 지나 다시 상기 추가압축기로 공급되는, 폐루프의 냉매 사이클을 형성할 수 있다.The boil-off gas treatment system of the vessel passes through the first additional line after the boil-off gas passes through the additional compressor, the second compressor, the second heat exchanger, the refrigerant pressure reducing device, and again the second heat exchanger. It is possible to form a closed loop refrigerant cycle, which is supplied to the additional compressor again.
상기 제1 압축기에 의해 압축된 증발가스와 상기 제2 압축기에 의해 압축된 증발가스가 합류되어, 일부는 상기 복귀라인을 따라 재액화되고, 다른 일부는 상기 재순환라인을 따라 상기 제2 열교환기, 상기 냉매감압장치, 및 다시 상기 제2 열교환기를 통과한 후, 상기 저장탱크로부터 배출되어 상기 제1 열교환기를 통과한 유체와 합류되고, 나머지 일부는 상기 연료수요처로 공급될 수 있다.The boil-off gas compressed by the first compressor and the boil-off gas compressed by the second compressor are combined to partially reliquefy along the return line, and the other part of the second heat exchanger along the recycle line; After passing through the refrigerant reducing device and the second heat exchanger again, the refrigerant may be discharged from the storage tank and joined with the fluid passing through the first heat exchanger, and the remaining part may be supplied to the fuel demand.
상기 제1 압축기에 의해 압축된 증발가스는, 일부는 상기 복귀라인을 따라 재액화되고, 나머지 일부는 상기 연료수요처로 공급되고, 상기 제2 압축기에 의해 압축된 증발가스는, 상기 재순환라인을 따라 상기 제2 열교환기, 상기 냉매감압장치, 및 다시 상기 제2 열교환기를 통과한 후, 상기 저장탱크로부터 배출되어 상기 제1 열교환기를 통과한 유체와 합류될 수 있다.The boil-off gas compressed by the first compressor is partially liquefied along the return line, the other part is supplied to the fuel demand, and the boil-off gas compressed by the second compressor is along the recycle line. After passing through the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger, the second heat exchanger may be discharged from the storage tank and joined with the fluid passing through the first heat exchanger.
상기 선박의 증발가스 처리 시스템은, 증발가스가 상기 제2 압축기, 상기 제2 열교환기, 상기 냉매감압장치, 다시 상기 제2 열교환기, 및 상기 추가압축기를 순환하는, 폐루프의 냉매 사이클을 형성할 수 있다. The evaporation gas treatment system of the vessel forms a closed loop refrigerant cycle in which the evaporation gas circulates the second compressor, the second heat exchanger, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor. can do.
상기 선박의 증발가스 처리 시스템은, 상기 추가압축기 하류의 재순환라인으로부터 분기되어, 상기 제1 압축기 상류의 상기 제1 공급라인과 연결되는 제2 추가라인; 상기 제1 압축기 하류의 제1 공급라인으로부터 분기되어, 상기 냉매감압장치 및 상기 제2 열교환기 상류의 재순환라인과 연결되는 제3 추가라인; 및 상기 제2 압축기 하류의 제2 공급라인으로부터 분기되어, 상기 추진압축기 상류의 상기 복귀라인과 연결되는 제4 추가라인;을 포함할 수 있다.The vessel's boil-off gas treatment system includes: a second additional line branched from a recirculation line downstream of the additional compressor and connected to the first supply line upstream of the first compressor; A third additional line branched from a first supply line downstream of the first compressor and connected to a recirculation line upstream of the refrigerant reducing device and the second heat exchanger; And a fourth additional line branched from a second supply line downstream of the second compressor and connected to the return line upstream of the propulsion compressor.
상기 선박의 증발가스 처리 시스템은, 증발가스가 상기 제2 압축기에 의해 압축된 후, 상기 재순환라인을 따라 상기 제2 열교환기, 상기 냉매감압장치, 다시 상기 제2 열교환기, 및 상기 추가압축기를 통과하여 다시 상기 제2 압축기로 다시 공급되는, 폐루프의 냉매 사이클을 형성할 수 있다.The boil-off gas treatment system of the vessel, after the boil-off gas is compressed by the second compressor, the second heat exchanger, the refrigerant pressure reducing device, again the second heat exchanger, and the additional compressor along the recirculation line A closed loop refrigerant cycle can be formed that passes through and is fed back to the second compressor.
상기 선박의 증발가스 처리 시스템은, 증발가스가 상기 제1 압축기에 의해 압축된 후, 상기 제3 추가라인 및 상기 재순환라인을 따라 상기 제2 열교환기로 공급되고, 상기 냉매감압장치, 다시 상기 제2 열교환기, 및 상기 추가압축기를 통과하여, 상기 제2 추가라인을 따라 상기 제1 압축기로 다시 공급되는, 폐루프의 냉매 사이클을 형성할 수 있다.The boil-off gas treatment system of the vessel, after the boil-off gas is compressed by the first compressor, is supplied to the second heat exchanger along the third additional line and the recirculation line, the refrigerant pressure reducing device, again the second Through a heat exchanger and the further compressor, a closed loop refrigerant cycle may be formed which is fed back to the first compressor along the second additional line.
상기 목적을 달성하기 위한 본 발명의 또 다른 측면에 따르면, 액화가스 저장탱크로부터 배출되는 증발가스를 둘로 분기하여, 상기 분기된 증발가스 중 한 흐름은 제1 압축기에 의해 압축시키고, 다른 흐름은 제2 압축기에 의해 압축시키고, 상기 제1 압축기에 의해 압축된 증발가스는 추진압축기에 의해 추가적으로 압축시킨 후에 재액화시켜 상기 저장탱크로 복귀시키고, 상기 제2 압축기에 의해 압축된 증발가스는 냉매 사이클을 순환시켜 상기 제1 압축기에 의해 압축된 증발가스를 냉각시키는 냉매로 사용하고, 상기 냉매 사이클을 순환하는 유체는, 추가압축기에 의해 압축된 후 상기 제2 압축기로 공급되는, 방법이 제공된다.According to another aspect of the present invention for achieving the above object, by dividing the boil-off gas discharged from the liquefied gas storage tank in two, one of the branched boil-off gas is compressed by the first compressor, the other flow is 2 is compressed by the compressor, and the boil-off gas compressed by the first compressor is further compressed by the propulsion compressor, and then re-liquefied to return to the storage tank, and the boil-off gas compressed by the second compressor is used for the refrigerant cycle. A method is provided wherein a fluid that circulates to cool the boil-off gas compressed by the first compressor, and the fluid that circulates the refrigerant cycle is supplied to the second compressor after being compressed by an additional compressor.
본 발명은, 기존의 부분 재액화 시스템(PRS)에 비하여, 증발가스가 제2 열교환기에 의한 추가적인 냉각 과정을 거친 후 감압되므로, 재액화 효율 및 재액화량을 증가시킬 수 있다. 특히, 별도의 냉매를 이용하는 냉동 사이클을 사용하지 않고도, 남는 증발가스의 대부분 또는 전부의 재액화가 가능하여 경제적이다.Compared with the conventional partial reliquefaction system (PRS), the present invention can increase the reliquefaction efficiency and the amount of reliquefaction since the boil-off gas is decompressed after additional cooling by the second heat exchanger. In particular, it is economical to re-liquefy most or all of the remaining boil-off gas without using a refrigeration cycle using a separate refrigerant.
또한, 본 발명에 따르면, 증발가스의 배출량, 선박의 운항 속도에 따른 엔진 부하 등에 따라 냉매 유량 및 냉열 공급의 유동적인 제어가 가능하다.In addition, according to the present invention, it is possible to control the flow rate of the refrigerant and the cooling heat supply in accordance with the discharge of the boil-off gas, the engine load according to the operating speed of the vessel.
본 발명의 일 실시예에 따르면, 기존에 이미 설치되어 있던 여분의 압축기를 이용하여 재액화 효율 및 재액화량을 높이므로, 선내 공간 확보에 기여하고, 추가로 압축기를 설치하는데 드는 비용을 절감할 수 있다. 특히, 여분의 압축기에 의해 압축된 증발가스뿐만 아니라 주 압축기에 의해 압축된 증발가스도 제2 열교환기에서 냉매로 사용할 수 있게 되어, 제2 열교환기에서 냉매로 사용하는 증발가스의 유량을 증가시킬 수 있으므로, 재액화 효율 및 재액화량을 더욱 증가시킬 수 있다.According to one embodiment of the present invention, since the re-liquefaction efficiency and the amount of reliquefaction are increased by using the spare compressor that is already installed, it contributes to securing the space on board and further reduces the cost of installing the compressor. Can be. In particular, the boil-off gas compressed by the main compressor as well as the boil-off gas compressed by the main compressor can be used as the refrigerant in the second heat exchanger, thereby increasing the flow rate of the boil-off gas used as the refrigerant in the second heat exchanger. As a result, the reliquefaction efficiency and the amount of reliquefaction can be further increased.
본 발명의 다른 실시예에 따르면, 제2 압축기에 의해 압축된 후 제2 열교환기에서 냉매로 사용되는 유체의 질량이 더 커지므로, 제2 열교환기에서의 재액화 효율과 재액화량을 증가시킬 수 있고, 냉매감압장치가 생산하는 동력을 활용할 수 있다.According to another embodiment of the present invention, since the mass of the fluid used as the refrigerant in the second heat exchanger after being compressed by the second compressor becomes larger, it is possible to increase the reliquefaction efficiency and the amount of reliquefaction in the second heat exchanger. Can utilize the power produced by the refrigerant pressure reducing device.
뿐만 아니라, 본 발명은, 추진압축기를 더 포함하여, 재액화 과정을 거치는 증발가스의 압력을 높일 수 있으므로 재액화 효율 및 재액화량을 더욱 증가시킬 수 있다.In addition, the present invention may further include a propulsion compressor to increase the pressure of the boil-off gas undergoing the reliquefaction process, thereby further increasing the reliquefaction efficiency and reliquefaction amount.
도 1은 종래의 부분 재액화 시스템을 개략적으로 나타낸 구성도이다.1 is a schematic view showing a conventional partial reliquefaction system.
도 2는 본 발명의 제1 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.Figure 2 is a schematic diagram showing a boil-off gas treatment system according to a first embodiment of the present invention.
도 3은 본 발명의 제2 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.3 is a configuration diagram schematically showing a boil-off gas treatment system according to a second embodiment of the present invention.
도 4는 본 발명의 제3 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.4 is a configuration diagram schematically showing a system for treating boil-off gas in accordance with a third embodiment of the present invention.
도 5는 본 발명의 제4 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.5 is a configuration diagram schematically showing a boil-off gas treatment system according to a fourth embodiment of the present invention.
도 6은 본 발명의 제5 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.Figure 6 is a schematic diagram showing a system for treating the boil-off gas in accordance with a fifth embodiment of the present invention.
도 7은 본 발명의 제6 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.7 is a configuration diagram schematically showing a boil-off gas treatment system according to a sixth embodiment of the present invention.
도 8은 온도 및 압력에 따른 메탄의 상변화를 개략적으로 나타낸 그래프이다.8 is a graph schematically showing the phase change of methane with temperature and pressure.
도 9는 서로 다른 압력하에서 열류량에 따른 메탄의 온도 값을 각각 나타낸 그래프이다.9 is a graph showing the temperature values of methane according to the amount of heat flow under different pressures.
이하 첨부한 도면을 참조하여 본 발명의 바람직한 실시예에 대한 구성 및 작용을 상세히 설명하면 다음과 같다. 본 발명의 선박은, 천연가스를 연료로 사용하는 엔진을 탑재한 선박 및 액화가스 저장탱크를 포함하는 선박 등에 다양하게 응용되어 적용될 수 있다. 또한, 하기 실시예는 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 하기 실시예에 한정되는 것은 아니다.Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The vessel of the present invention can be applied to various applications, such as a vessel equipped with an engine using natural gas as a fuel, and a vessel including a liquefied gas storage tank. In addition, the following examples may be modified in many different forms, and the scope of the present invention is not limited to the following examples.
본 발명의 후술할 증발가스 처리를 위한 시스템들은 저온 액체화물 또는 액화가스를 저장할 수 있는 저장탱크가 설치된 모든 종류의 선박과 해상 구조물, 즉 액화천연가스 운반선, 액화에탄가스(Liquefied Ethane Gas) 운반선, LNG RV와 같은 선박을 비롯하여, LNG FPSO, LNG FSRU와 같은 해상 구조물에 적용될 수 있다. 다만 후술하는 실시예들에서는 설명의 편의상 대표적인 저온 액체화물인 액화천연가스를 예로 들어 설명한다.The system for the treatment of boil-off gas to be described later of the present invention includes all kinds of vessels and offshore structures, that is, liquefied natural gas carriers, liquefied ethane gas carriers, equipped with storage tanks capable of storing low temperature liquid cargo or liquefied gas, It can be applied to ships such as LNG RV, as well as offshore structures such as LNG FPSO, LNG FSRU. However, embodiments described later will be described by taking liquefied natural gas as a representative low temperature liquid cargo for the convenience of description.
또한, 본 발명의 각 라인에서의 유체는, 시스템의 운용 조건에 따라, 액체 상태, 기액 혼합 상태, 기체 상태, 초임계유체 상태 중 어느 하나의 상태일 수 있다.In addition, the fluid in each line of the present invention may be in any one of a liquid state, a gas-liquid mixed state, a gas state, and a supercritical fluid state, depending on the operating conditions of the system.
도 1은 종래의 부분 재액화 시스템을 개략적으로 나타낸 구성도이다.1 is a schematic view showing a conventional partial reliquefaction system.
도 1을 참조하면, 종래의 부분 재액화 시스템에서, 액체화물을 저장하는 저장탱크에서 발생하여 배출되는 증발가스는, 배관을 따라 이송되어 증발가스 압축부(10)에서 압축된다.Referring to FIG. 1, in the conventional partial reliquefaction system, the boil-off gas generated and discharged from the storage tank for storing the liquid cargo is transferred along the pipe and compressed in the boil-off gas compression unit 10.
저장탱크(T)는 액화천연가스 등의 액화가스를 극저온 상태로 저장할 수 있도록 밀봉 및 단열 방벽을 갖추고 있지만, 외부로부터 전달되는 열을 완벽하게 차단할 수는 없고, 탱크 내에서는 액화가스의 증발이 지속적으로 이루어지며 탱크 내압이 상승할 수 있는데, 이러한 증발가스에 의한 탱크 압력의 과도한 상승을 막고, 적정한 수준의 내압을 유지하기 위해 저장탱크 내부의 증발가스를 배출시켜, 증발가스 압축부(10)로 공급한다.The storage tank (T) has a sealing and insulation barrier to store liquefied gas such as liquefied natural gas in a cryogenic state, but it cannot completely block the heat transmitted from the outside, and the liquefied gas evaporates continuously in the tank. The internal pressure of the tank may be increased, and to prevent excessive increase in the tank pressure due to the boil-off gas, and to discharge the boil-off gas inside the storage tank to maintain an appropriate level of internal pressure, the boil-off gas compression unit 10 may be used. Supply.
저장탱크로부터 배출되어 증발가스 압축부(10)에서 압축된 증발가스를 제1 스트림이라 할 때, 압축된 증발가스의 제1 스트림을 제2 스트림과 제3 스트림으로 나누어, 제2 스트림은 액화시켜 저장탱크(T)로 복귀시키도록 구성하고, 제3 스트림은 선내의 추진용 엔진이나 발전용 엔진과 같은 가스 연료 소비처로 공급하도록 구성할 수 있다. 이 경우 증발가스 압축부(10)에서는 연료 소비처의 공급 압력까지 증발가스를 압축할 수 있고, 제2 스트림은 필요에 따라 증발가스 압축부의 전부 또는 일부를 거쳐 분기시킬 수 있다. 연료 소비처의 연료 필요량에 따라 제3 스트림으로 압축된 증발가스 전부를 공급할 수도 있고, 제2 스트림으로 전량을 공급하여 압축된 증발가스 전부를 저장탱크로 복귀시킬 수도 있다. 가스 연료 소비처로는 고압가스분사엔진(예를 들어, MDT사가 개발한 ME-GI 엔진 등) 및 저압가스분사엔진(예를 들어, Wartsila社의 X-DF 엔진(Generation X-Dual Fuel engine) 등)을 비롯하여, DF Generator, 가스 터빈, DFDE 등을 예로 들 수 있다. When the boil-off gas discharged from the storage tank and compressed in the boil-off gas compression unit 10 is called a first stream, the first stream of compressed boil-off gas is divided into a second stream and a third stream, and the second stream is liquefied. It is configured to return to the storage tank (T), and the third stream can be configured to supply to a gas fuel consumer such as a propulsion engine or a power generation engine on board. In this case, the boil-off gas compression unit 10 may compress the boil-off gas to the supply pressure of the fuel consumer, and the second stream may branch through all or part of the boil-off gas compression unit as necessary. Depending on the fuel consumption of the fuel consumer, all of the compressed boil-off gas may be supplied to the third stream, or all of the compressed boil-off gas may be supplied to the second stream to return the compressed boil-off gas to the storage tank. Gas fuel consumption sources include high pressure gas injection engines (eg, ME-GI engines developed by MDT) and low pressure gas injection engines (eg, Wartsila's Generation X-Dual Fuel engine). ), DF Generator, gas turbine, DFDE and the like.
이때, 압축된 증발가스의 제2 스트림을 액화시킬 수 있도록 열교환기(20)를 설치하는데, 저장탱크에서 발생하는 증발가스를 압축된 증발가스의 냉열 공급원으로 이용한다. 열교환기(20)를 거치면서 증발가스 압축부에서의 압축과정에서 온도가 상승한 압축된 증발가스, 즉 제2 스트림은 냉각되고, 저장탱크에서 발생하여 열교환기(20)로 도입된 증발가스는 가열되어 증발가스 압축부(10)로 공급된다. At this time, the heat exchanger 20 is installed to liquefy the second stream of compressed boil-off gas, and the boil-off gas generated from the storage tank is used as a cold heat source of the compressed boil-off gas. The compressed boil-off gas, ie, the second stream, which has risen in temperature during the compression in the boil-off gas compression unit while passing through the heat exchanger 20 is cooled, and the boil-off gas generated in the storage tank and introduced into the heat exchanger 20 is heated. And is supplied to the boil-off gas compression unit 10.
압축되기 전 증발가스의 유량이 제2 스트림의 유량보다 많기 때문에, 압축된 증발가스의 제2 스트림은 압축되기 전의 증발가스로부터 냉열을 공급받아 적어도 일부가 액화될 수 있다. 이와 같이 열교환기에서는 저장탱크로부터 배출된 직후의 저온 증발가스와 증발가스 압축부에서 압축된 고압 상태의 증발가스를 열교환시켜 고압 증발가스를 액화시킨다.Since the flow rate of the boil-off gas before being compressed is greater than the flow rate of the second stream, the second stream of compressed boil-off gas may be supplied with cold heat from the boil-off gas before being compressed to at least partially liquefy. As described above, the heat exchanger heat-exchanges the low-temperature evaporated gas immediately after being discharged from the storage tank and the high-pressure evaporated gas compressed by the evaporated gas compression unit to liquefy the high-pressure evaporated gas.
열교환기(20)를 거친 제2 스트림의 증발가스는 팽창밸브 또는 팽창기와 같은 팽창수단(30)을 통과하면서 감압되면서 추가로 냉각되어, 기액분리기(40)에 공급된다. 액화된 증발가스는 기액분리기에서 기체와 액체 성분이 분리되어, 액체성분, 즉 액화천연가스는 저장탱크로 복귀되고, 기체성분, 즉 증발가스는 저장탱크로부터 배출되어 열교환기(20) 및 증발가스 압축부(10)로 공급되는 증발가스 흐름에 증발가스 흐름에 합류되거나, 다시 열교환기(20)로 공급되어 증발가스 압축부(10)에서 압축된 고압 상태의 증발가스를 열교환시키는 냉열 공급원으로 활용될 수도 있다. 물론, 가스연소장치(Gas Combustion Unit; GCU) 등으로 보내 연소시키거나, 가스 소모처(가스엔진 포함)에 보내 소모시킬 수도 있다. 증발가스 흐름에 합류되기 전 기액분리기에서 분리된 기체를 추가로 감압시키기 위한 또 다른 팽창수단(50)이 더 설치될 수 있다.The boil-off gas of the second stream passing through the heat exchanger 20 is further cooled while being decompressed while passing through expansion means 30 such as an expansion valve or expander, and is supplied to the gas-liquid separator 40. The liquefied boil-off gas is separated from the gas and the liquid component in the gas-liquid separator, and the liquid component, that is, the liquefied natural gas, is returned to the storage tank, and the gas component, that is, the boil-off gas, is discharged from the storage tank so as to exchange the heat exchanger 20 and the boil-off gas. The evaporation gas flow supplied to the compression unit 10 is joined to the evaporation gas flow, or supplied to the heat exchanger 20 and used as a cold heat source for heat-exchanging the high-pressure evaporation gas compressed by the evaporation gas compression unit 10. May be Of course, it may be sent to a gas combustion unit (GCU) or the like for combustion, or may be sent to a gas consumer (including a gas engine) for consumption. Another expansion means 50 may be further installed to further depressurize the gas separated in the gas-liquid separator before joining the boil-off gas stream.
도 2는 본 발명의 제1 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.Figure 2 is a schematic diagram showing a boil-off gas treatment system according to a first embodiment of the present invention.
도 2를 참조하면, 본 실시예의 시스템은, 저장탱크에 저장된 저온 액체화물로부터 발생하는 증발가스(Boil Off Gas)를 공급받아 증발가스를 냉매로 순환시키는 냉매순환부(300a)를 구성한 것이 특징이다. 2, the system of the present embodiment is characterized in that the refrigerant circulation section 300a for receiving the boil off gas generated from the low temperature liquid cargo stored in the storage tank to circulate the boil off gas to the refrigerant .
이를 위해 저장탱크로부터 냉매순환부(300a)로 증발가스를 공급하는 냉매공급라인(CSLa)을 포함하며, 냉매공급라인에는 밸브(400a)가 마련되어, 냉매순환부를 순환할 수 있는 충분한 양의 증발가스가 공급되면 냉매공급라인(CSLa)을 차단하여, 냉매순환부(300a)는 폐루프(closed loop)로 운용된다. To this end, it comprises a refrigerant supply line (CSLa) for supplying the boil-off gas from the storage tank to the refrigerant circulation unit 300a, the valve supply line is provided with a valve 400a, a sufficient amount of evaporation gas to circulate the refrigerant circulation unit When is supplied to block the refrigerant supply line (CSLa), the refrigerant circulation unit 300a is operated in a closed loop (closed loop).
전술한 기본 실시예에서와 마찬가지로 본 제1 확장 실시예에서도 저장탱크(T)의 저온 액체화물로부터 발생하는 증발가스를 압축하는 제1 압축기(100a)가 마련된다. 저장탱크에서 발생한 증발가스는 증발가스공급라인(BLa)을 따라 제1 압축기(100a)로 도입된다. As in the basic embodiment described above, in the first expanded embodiment, the first compressor 100a is provided to compress the boil-off gas generated from the low temperature liquid cargo of the storage tank T. The boil-off gas generated in the storage tank is introduced into the first compressor 100a along the boil-off gas supply line BLa.
본 실시예들의 저장탱크(T)는 액체화물의 하중이 단열층에 직접 가해지지 않는 독립탱크형(Independent Type) 탱크, 또는 화물의 하중이 단열층에 직접 가해지는 멤브레인형(Membrane Type) 탱크로 만들어질 수 있다. 독립탱크형 탱크인 경우에는, 2 barg 이상의 압력에 견디도록 설계된 압력용기로 사용하는 것도 가능하다.The storage tank T of the present embodiments may be made of an independent type tank in which the load of liquid cargo is not directly applied to the insulation layer, or a membrane type tank in which the load of cargo is directly applied to the insulation layer. Can be. In the case of independent tank type tanks, it is also possible to use a pressure vessel designed to withstand pressures of 2 barg or more.
한편, 본 실시예들에서는 증발가스의 재액화를 위한 라인만을 도시하였으나, 제1 압축기(100a)에서 압축된 증발가스는 선박 또는 해상 구조물의 추진용 엔진 및 발전용 엔진을 포함하는 연료수요처에 연료로 공급될 수 있고, 연료 소모량이 증발가스 전량을 소비할 수 있을 때에는 재액화되는 증발가스가 없을 수도 있다. 선박이 정박하고 있는 때와 같이 가스 연료의 소모량이 적거나 없는 경우에는, 증발가스의 전량을 재액화라인(RLa)으로 공급할 수도 있다. Meanwhile, although only lines for reliquefaction of the boil-off gas are shown in the present embodiments, the boil-off gas compressed by the first compressor 100a is fueled to a fuel demand including a propulsion engine and a power generation engine of a ship or offshore structure. May be supplied, and there may be no boil-off gas that is reliquefied when the fuel consumption can consume the whole boil-off gas. When the gaseous fuel consumption is low or absent, such as when the ship is anchored, the entire amount of the boil-off gas may be supplied to the reliquefaction line RLa.
압축된 증발가스는 증발가스 재액화라인(RLa)을 따라 제1 열교환기(200a)로 공급되는데, 제1 열교환기(200a)는 증발가스 재액화라인(RLa)과 증발가스공급라인(BLa)에 걸쳐 마련되어, 제1 압축기(100a)로 도입될 증발가스와 제1 압축기(100a)의 적어도 일부를 거쳐 압축된 증발가스를 열교환시킨다. 압축과정에서 온도가 높아진 증발가스는, 저장탱크에서 발생하여 제1 압축기(100a)로 도입될 저온 증발가스와 열교환을 통해 냉각된다. The compressed boil-off gas is supplied to the first heat exchanger 200a along the boil-off gas reliquefaction line RLa, and the first heat exchanger 200a is the boil-off gas reliquefaction line RLa and the boil-off gas supply line BLa. It is provided over, and heat exchanges the boil-off gas to be introduced into the first compressor (100a) and the boil-off gas compressed through at least a portion of the first compressor (100a). The boil-off gas whose temperature is increased in the compression process is cooled by heat exchange with the low-temperature boil-off gas generated in the storage tank and introduced into the first compressor 100a.
제1 열교환기(200a)의 하류에는 제2 열교환기(500a)가 마련되어, 압축 후 제1 열교환기(200a)에서 열교환된 증발가스는 냉매순환부(300a)를 순환하는 증발가스와 열교환을 통해 추가로 냉각된다. A second heat exchanger 500a is provided downstream of the first heat exchanger 200a, and the boil-off gas heat-exchanged in the first heat exchanger 200a after the compression is exchanged with an evaporation gas circulating through the refrigerant circulation part 300a. Further cooling.
냉매순환부(300a)는, 저장탱크로부터 공급되는 증발가스를 압축하는 냉매압축기(310a)와, 냉매압축기에서 압축된 증발가스를 냉각하는 제1 냉각기(320a)와, 제1 냉각기(320a)에서 냉각된 증발가스를 감압시켜 추가냉각하는 냉매감압장치(330a)를 포함한다. 냉매감압장치(330a)는 증발가스를 단열팽창시켜 냉각하는 팽창밸브 또는 팽창기일 수 있다. The refrigerant circulation unit 300a includes a refrigerant compressor 310a for compressing the evaporated gas supplied from the storage tank, a first cooler 320a for cooling the evaporated gas compressed by the refrigerant compressor, and a first cooler 320a. And a refrigerant pressure reducing device 330a for further cooling by reducing the cooled boil-off gas. The refrigerant decompression device 330a may be an expansion valve or an expander that adiabatically expands and cools the boil-off gas.
냉매감압장치(330a)를 거쳐 냉각된 증발가스는 냉매순환라인(CCLa)을 따라 냉매로서 제2 열교환기(500a)로 공급되어 제2 열교환기(500a)에서, 제1 열교환기(200a)를 거쳐 공급된 증발가스와 열교환을 통해 증발가스를 냉각시키게 된다. 제2 열교환기(500a)를 거친 냉매순환라인(CCLa)의 증발가스는 냉매압축기(310a)로 순환되어, 전술한 압축 및 냉각과정을 거치면서 냉매순환라인을 순환하게 된다.The boil-off gas cooled through the refrigerant decompression device 330a is supplied to the second heat exchanger 500a as a refrigerant along the refrigerant circulation line CCLa, so that the first heat exchanger 200a is transferred from the second heat exchanger 500a. The boil-off gas is cooled through heat exchange with the boil-off gas. The boil-off gas of the refrigerant circulation line CCLa passing through the second heat exchanger 500a is circulated to the refrigerant compressor 310a to circulate the refrigerant circulation line through the above-described compression and cooling process.
한편, 제2 열교환기(500a)에서 냉각된 증발가스 재액화라인(RLa)의 증발가스는 제1 감압장치(600a)를 거쳐 감압된다. 제1 감압장치(600a)는 줄-톰슨(Joule-Thomson) 밸브 등의 팽창밸브, 또는 팽창기일 수 있다.Meanwhile, the boil-off gas of the boil-off gas reliquefaction line RLa cooled in the second heat exchanger 500a is reduced in pressure through the first pressure reducing device 600a. The first pressure reducing device 600a may be an expansion valve such as a Joule-Thomson valve or an expander.
갑압된 증발가스는 제1 감압장치(600a)의 하류의 기액분리기(700a)로 공급되어 기액분리되고, 기액분리기(700a)에서 분리된 액체, 즉 액화천연가스는 저장탱크(T)로 공급되어 재저장된다. The pressurized boil-off gas is supplied to the gas-liquid separator 700a downstream of the first decompression device 600a and gas-liquid separated, and the liquid separated from the gas-liquid separator 700a, that is, liquefied natural gas, is supplied to the storage tank T. Restored.
기액분리기(700a)에서 분리된 기체, 즉 증발가스는 제2 감압장치(800a)를 거쳐 추가로 감압되고, 저장탱크(T)로부터 제1 열교환기(200a)로 도입될 증발가스의 흐름에 증발가스 흐름에 합류되거나, 다시 제1 열교환기(200a)로 공급되어 제1 압축기(100a)에서 압축된 고압 상태의 증발가스를 열교환시키는 냉열 공급원으로 활용될 수도 있다. 물론, 가스연소장치(Gas Combustion Unit; GCU) 등으로 보내 연소시키거나, 연료수요처(가스엔진 포함)에 보내 소모시킬 수도 있다.The gas separated from the gas-liquid separator 700a, ie, the boil-off gas, is further decompressed through the second decompression device 800a and evaporated in the flow of the boil-off gas to be introduced into the first heat exchanger 200a from the storage tank T. It may be used as a cold heat source that joins the gas stream or is supplied to the first heat exchanger 200a to heat-exchange the boil-off gas under high pressure compressed by the first compressor 100a. Of course, it may be sent to a gas combustion unit (GCU) for combustion, or may be sent to a fuel demand (including a gas engine) for consumption.
도 3은 본 발명의 제2 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.3 is a configuration diagram schematically showing a boil-off gas treatment system according to a second embodiment of the present invention.
도 3을 참조하면, 본 실시예는 냉매순환부(300b)에서 제1 냉각기(320b)로부터 냉매감압장치(330b)로 도입될 증발가스를, 냉매감압장치(330b)에서 감압된 증발가스와 열교환으로 냉각시킨 후에 냉매감압장치(330b)로 공급하도록 구성한 것이다. Referring to FIG. 3, in the present embodiment, an evaporation gas to be introduced into the refrigerant decompression device 330b from the first cooler 320b in the refrigerant circulation part 300b is exchanged with the evaporated gas decompressed by the refrigerant decompression device 330b. After cooling to, it is configured to supply to the refrigerant pressure reducing device (330b).
냉매감압장치(330b)를 거쳐 감압되면서 증발가스는 냉각되므로, 냉매감압장치 하류의 증발가스는 냉매감압장치 상류의 증발가스보다 온도가 낮고, 본 실시예는 이러한 점을 고려하여, 냉매감압장치 상류의 증발가스를 하류의 증발가스와 열교환시켜 냉각한 후 감압장치로 도입시킨다. 이를 위해 도 3에 도시된 바와 같이 제2 열교환기(500b)로 냉매감압장치(330b) 상류의 증발가스를 공급할 수 있다(도 3의 A부분). 필요에 따라 냉매감압장치 상류와 하류의 증발가스가 열교환할 수 있는 별도의 열교환 장치를 추가로 구성할 수도 있다. Since the evaporated gas is cooled while being decompressed via the refrigerant decompression device 330b, the evaporation gas downstream of the refrigerant decompression device is lower in temperature than the evaporation gas upstream of the refrigerant decompression device. The boil-off gas of heat exchanged with the downstream boil-off gas, cooled, and introduced into a decompression device. To this end, as shown in FIG. 3, the boil-off gas upstream of the refrigerant reducing device 330b may be supplied to the second heat exchanger 500b (part A of FIG. 3). If necessary, a separate heat exchanger may be further configured to exchange heat with the boil-off gas upstream and downstream of the refrigerant pressure reducing device.
이상에서 살펴본 바와 같이, 본 실시예들의 시스템은 저장탱크 액체화물에서 발생하는 증발가스를 재액화하여 저장할 수 있으므로, 액체화물의 수송률을 높일 수 있다. 특히 선내 가스 소비처의 연료 소모량이 적은 경우에도 저장탱크의 압력 상승을 막기 위해 가스연소장치(Gas Combustion Unit; GCU) 등에서 연소시켜 낭비하는 화물의 양을 줄이거나 없앨 수 있어, 에너지가 낭비되는 것을 막을 수 있다. As described above, the system of the embodiments may re-liquefy and store the evaporated gas generated from the storage tank liquid cargo, thereby increasing the transport rate of the liquid cargo. In particular, even if the fuel consumption of onboard gas consumption is low, the gas compression unit (GCU) can reduce or eliminate the amount of waste by burning it in a gas combustion unit (GCU) to prevent the pressure rise. Can be.
또한, 증발가스를 냉매로 순환시켜, 증발가스의 재액화를 위한 냉열원으로 활용함으로써 별도의 냉매 사이클을 구성하지 않고도 증발가스를 효과적으로 재액화시킬 수 있으며, 별도의 냉매를 공급할 필요가 없으므로, 선내 공간 확보에 기여하고 경제적이다. 또한, 냉매 사이클에서 냉매가 부족하면 저장탱크로부터 보충할 수 있어 원활한 냉매 보충이 이루어질 수 있고, 냉매 사이클의 운용이 효과적으로 이루어질 수 있다. In addition, by circulating the boil-off gas into the refrigerant, as a cooling heat source for the re-liquefaction of the boil-off gas can be effectively re-liquefied the boil-off gas without configuring a separate refrigerant cycle, it is not necessary to supply a separate refrigerant, It contributes to space and is economical. In addition, when the refrigerant is insufficient in the refrigerant cycle can be replenished from the storage tank can be smoothly replenishment, the operation of the refrigerant cycle can be made effectively.
이와 같이 증발가스 자체의 냉열을 다단계로 이용하여 증발가스를 재액화할 수 있어, 선내 증발가스 처리를 위한 시스템 구성을 간소화할 수 있고, 복잡한 증발가스 처리를 위한 장치의 설치 및 운용에 소요되는 비용을 절감할 수 있다.In this way, it is possible to re-liquefy the boil-off gas by using the cold heat of the boil-off gas itself in multiple stages, simplifying the system configuration for boil-off gas treatment on board, and the cost of installing and operating a device for complex boil-off gas treatment. Can reduce the cost.
도 4는 본 발명의 제3 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.4 is a configuration diagram schematically showing a system for treating boil-off gas in accordance with a third embodiment of the present invention.
도 4를 참조하면, 본 실시예의 선박은, 저장탱크(T) 하류에 설치되는 제1 열교환기(110); 제1 열교환기(110) 하류에 설치되어, 저장탱크(T)로부터 배출된 증발가스를 압축시키는 제1 압축기(120) 및 제2 압축기(122); 제1 압축기(120)에 의해 압축된 증발가스의 온도를 낮추는 제1 냉각기(130); 제2 압축기(122)에 의해 압축된 증발가스의 온도를 낮추는 제2 냉각기(132); 제1 압축기(120) 상류에 설치되는 제1 밸브(191); 제1 냉각기(130) 하류에 설치되는 제2 밸브(192); 제2 압축기(122) 상류에 설치되는 제3 밸브(193); 제2 냉각기(132) 하류에 설치되는 제4 밸브(194); 제1 열교환기(110)에 의해 냉각된 증발가스를 추가적으로 냉각시키는 제2 열교환기(140); 제2 열교환기(140)를 통과한 증발가스를 팽창시킨 후 다시 제2 열교환기(140)로 보내는 냉매감압장치(160); 및 제2 열교환기(140)에 의해 추가적으로 냉각된 증발가스를 팽창시키는 제1 감압장치(150);를 포함한다.4, the ship of this embodiment, the first heat exchanger 110 is installed downstream of the storage tank (T); A first compressor 120 and a second compressor 122 installed downstream of the first heat exchanger 110 to compress the boil-off gas discharged from the storage tank T; A first cooler 130 for lowering the temperature of the boil-off gas compressed by the first compressor 120; A second cooler 132 for lowering the temperature of the boil-off gas compressed by the second compressor 122; A first valve 191 installed upstream of the first compressor 120; A second valve 192 installed downstream of the first cooler 130; A third valve 193 installed upstream of the second compressor 122; A fourth valve 194 installed downstream of the second cooler 132; A second heat exchanger 140 for further cooling the boil-off gas cooled by the first heat exchanger 110; A refrigerant pressure reducing device (160) for expanding the boil-off gas passing through the second heat exchanger (140) and sending it back to the second heat exchanger (140); And a first pressure reducing device 150 for expanding the boil-off gas further cooled by the second heat exchanger 140.
저장탱크(T)에서 자연적으로 발생된 후 배출된 증발가스는, 제1 공급라인(L1)을 따라 연료수요처(180)에 공급된다. 제1 열교환기(110)는 제1 공급라인(L1)에 설치되어 저장탱크(T)에서 배출된 직후의 증발가스로부터 냉열을 회수한다. 본 실시예의 선박은, 연료수요처(180) 상류에 설치되어, 연료수요처(180)로 보내지는 증발가스의 유량 및 개폐를 조절하는 제11 밸브(203)를 더 포함할 수 있다.The boil-off gas naturally generated in the storage tank T and then discharged is supplied to the fuel demand 180 along the first supply line L1. The first heat exchanger 110 is installed in the first supply line (L1) to recover the cold heat from the boil-off gas immediately after being discharged from the storage tank (T). The vessel of the present embodiment may further include an eleventh valve 203 installed upstream of the fuel demand unit 180 to control the flow rate and opening and closing of the boil-off gas sent to the fuel demand unit 180.
제1 열교환기(110)는, 저장탱크(T)로부터 배출되는 증발가스를 공급받아, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되는 증발가스를 냉각시키는 냉매로 사용한다. 복귀라인(L3) 상에는 증발가스의 유량 및 개폐를 조절하는 제5 밸브(195)가 설치될 수 있다.The first heat exchanger 110 receives the boil-off gas discharged from the storage tank T, and uses the boil-off gas to cool the boil-off gas supplied to the first heat exchanger 110 along the return line L3. A fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
제1 압축기(120) 및 제2 압축기(122)는 제1 열교환기(110)를 통과한 증발가스를 압축시킨다. 제1 압축기(120)는 제1 공급라인(L1) 상에 설치되며, 제2 압축기(122)는, 제2 공급라인(L2) 상에 설치된다. 제2 공급라인(L2)은, 제1 압축기(120) 상류의 제1 공급라인(L1)으로부터 분기하여 제1 압축기(120) 하류의 제1 공급라인(L1)에 연결된다. 또한, 제1 압축기(120)와 제2 압축기(122)는 병렬로 설치되며, 동일한 성능의 압축기일 수 있다.The first compressor 120 and the second compressor 122 compress the boil-off gas passed through the first heat exchanger 110. The first compressor 120 is installed on the first supply line L1, and the second compressor 122 is installed on the second supply line L2. The second supply line L2 branches from the first supply line L1 upstream of the first compressor 120 and is connected to the first supply line L1 downstream of the first compressor 120. In addition, the first compressor 120 and the second compressor 122 may be installed in parallel and may be compressors having the same performance.
일반적으로 선박에는, 제1 압축기(120) 및 제1 냉각기(130)가 고장나는 경우에 대비하여 제2 압축기(122) 및 제2 냉각기(132)를 추가적으로 설치한다. 종래에는, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나지 않은 평상시에는, 제2 압축기(122) 및 제2 냉각기(132)를 사용하지 않았다.In general, a ship additionally installs a second compressor 122 and a second cooler 132 in case the first compressor 120 and the first cooler 130 fail. Conventionally, the 2nd compressor 122 and the 2nd cooler 132 were not used normally when the 1st compressor 120 or the 1st cooler 130 did not fail.
즉, 종래에는, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나지 않은 평상시에는, 제2 압축기(122) 상류의 제3 밸브(193)와 제2 냉각기(132) 하류의 제4 밸브(194)를 닫아, 증발가스가 제1 압축기(120) 및 제1 냉각기(130)를 통과하여 연료수요처(180)로 공급되도록 하였고, 제1 압축기(120) 또는 제1 냉각기(130)가 고장난 경우에는, 제2 압축기(122) 상류의 제3 밸브(193)와 제2 냉각기(132) 하류의 제4 밸브(194)는 열고, 제1 압축기(120) 상류의 제1 밸브(191)와 제1 냉각기(130) 하류의 제2 밸브(192)는 닫아, 증발가스가 제2 압축기(122) 및 제2 냉각기(132)를 통과하여 연료수요처(180)로 공급되도록 하였다.That is, conventionally, when the first compressor 120 or the first cooler 130 is not broken, the fourth valve 193 upstream of the second compressor 122 and the fourth downstream of the second cooler 132 are normally used. The valve 194 was closed to allow boil-off gas to pass through the first compressor 120 and the first cooler 130 to be supplied to the fuel demand 180, and the first compressor 120 or the first cooler 130 was In case of a failure, the third valve 193 upstream of the second compressor 122 and the fourth valve 194 downstream of the second cooler 132 are opened, and the first valve 191 upstream of the first compressor 120 is opened. The second valve 192 downstream of the first cooler 130 is closed to allow the boil-off gas to be supplied to the fuel demand 180 through the second compressor 122 and the second cooler 132.
본 발명은, 종래에 선박에 설치되어 있음에도 사용되지 않던 제2 압축기(122) 및 제2 냉각기(132)를 사용하여 증발가스의 재액화 효율 및 재액화량을 높이기 위한 것으로서, 제2 압축기(122)에 의해 압축된 증발가스를, 일부는 연료수요처(180)로 보내고, 다른 일부는 제2 열교환기(140)에서 증발가스를 추가적으로 냉각시키는 냉매로 사용한다.The present invention is to improve the re-liquefaction efficiency and the amount of re-liquefaction of the boil-off gas by using the second compressor 122 and the second cooler 132, which has not been used in the prior art installed on the ship, the second compressor 122 The evaporated gas compressed by) is sent to the fuel demand unit 180, and the other part is used as a refrigerant to further cool the evaporated gas in the second heat exchanger 140.
도 8은 온도 및 압력에 따른 메탄의 상변화를 개략적으로 나타낸 그래프이다. 도 8을 참조하면, 메탄은 대략 -80℃ 이상의 온도 및 대략 55bar 이상의 압력 조건이 되면 초임계유체 상태가 된다. 즉, 메탄의 경우, 대략 -80℃, 55bar 상태가 임계점이 된다. 초임계유체 상태는, 액체 상태나 기체상태와는 다른 제3의 상태이다. 8 is a graph schematically showing the phase change of methane with temperature and pressure. Referring to FIG. 8, the methane is in a supercritical fluid state at a temperature of about −80 ° C. or more and a pressure of about 55 bar or more. That is, in the case of methane, the critical point is about -80 ℃, 55bar state. The supercritical fluid state is a third state different from the liquid state or the gas state.
한편, 임계점 이상의 압력에서 임계점보다 낮은 온도를 갖게 되면 일반적인 액체 상태와는 다른, 밀도가 높은 초임계유체 상태와 유사한 상태가 될 수도 있는데, 임계점이상의 압력 및 임계점 이하의 온도를 가지는 증발가스의 상태를, 이하, "고압액체상태"라고 한다.On the other hand, having a temperature lower than the critical point at a pressure above the critical point may result in a state similar to a dense supercritical fluid state, which is different from a general liquid state. Hereafter, it is called "high pressure liquid state."
제1 압축기(120) 또는 제2 압축기(122)에 의해 압축된 증발가스는 압축된 정도에 따라 기체상태일 수도 있고, 초임계유체 상태일 수도 있다.The boil-off gas compressed by the first compressor 120 or the second compressor 122 may be in a gaseous state or a supercritical fluid state depending on the degree of compression.
복귀라인(L3)를 통해 제1 열교환기(110)로 보내지는 증발가스가 기체상태인 경우에는, 증발가스는 제1 열교환기(110)를 통과하면서 온도가 낮아져 액체와 기체의 혼합상태가 될 수 있고, 초임계유체 상태인 경우에는, 제1 열교환기(110)를 통과하면서 온도가 낮아져 "고압액체상태"가 될 수 있다.When the boil-off gas sent to the first heat exchanger 110 through the return line L3 is in a gaseous state, the boil-off gas passes through the first heat exchanger 110 and the temperature is lowered to become a mixed state of liquid and gas. In the case of the supercritical fluid state, the temperature may be lowered while passing through the first heat exchanger 110 to become a “high pressure liquid state”.
제1 열교환기(110)에 의해 냉각된 증발가스는, 제2 열교환기(140)를 통과하면서 온도가 더 낮아지게 되는데, 제1 열교환기(110)를 통과한 증발가스가 액체와 기체의 혼합상태인 경우에는, 증발가스는 제2 열교환기(140)를 통과하면서 온도가 더 낮아져 액체의 비율이 더 높은 혼합상태가 되거나 액체상태가 되고, "고압액체상태"인 경우에는, 제2 열교환기(140)를 통과하면서 온도가 더 낮아지게 된다.The boil-off gas cooled by the first heat exchanger 110 has a lower temperature while passing through the second heat-exchanger 140. The boil-off gas passed through the first heat exchanger 110 is mixed with liquid and gas. In the case of the state, the boil-off gas passes through the second heat exchanger 140, and the temperature is lowered so that the proportion of the liquid becomes a mixed state or becomes a liquid state, and in the case of the "high pressure liquid state", the second heat exchanger The temperature is lowered while passing through 140.
또한, 제2 열교환기(140)를 통과한 증발가스가 "고압액체상태"인 경우에도, 증발가스는 제1 감압장치(150)를 통과하면서 압력이 낮아져 액체상태가 되거나 액체와 기체의 혼합상태가 된다.In addition, even when the boil-off gas passing through the second heat exchanger 140 is in the "high-pressure liquid state", the boil-off gas passes through the first pressure reducing device 150 to lower the pressure to become a liquid state or a mixed state of liquid and gas. Becomes
증발가스가 제1 감압장치(150)에 의해 압력이 같은 정도(도 8의 P)로 낮아진다고 하더라도, 온도가 더 높은 상태에서 감암되는 경우(도 8의 X→X')보다 온도가 더 낮은 상태에서 감압된 경우(도 8의 Y→Y')에 액체의 비율이 더 높은 혼합상태가 되는 것을 알 수 있다. 또한, 온도를 더 낮출 수 있다면 이론적으로 증발가스를 100% 재액화 시킬 수 있음(도 8의 Z→Z')을 알 수 있다. 따라서, 제1 감압장치(150)를 통과하기 전에 제2 열교환기(140)에 의해 증발가스를 한 번 더 냉각시키면 재액화 효율 및 재액화량이 높아질 수 있다.Although the boil-off gas is lowered to the same degree (P in FIG. 8) by the first decompression device 150, the temperature is lower than that in the case where the temperature of the boil-off gas is reduced (X → X ′ in FIG. 8). It can be seen that when the pressure is reduced in the state (Y → Y ′ in FIG. 8), the proportion of the liquid becomes a higher mixed state. In addition, it can be seen that if the temperature can be further lowered, theoretically, 100% of the evaporated gas can be reliquefied (Z → Z ′ in FIG. 8). Therefore, if the boil-off gas is further cooled by the second heat exchanger 140 before passing through the first pressure reducing device 150, the re-liquefaction efficiency and the amount of re-liquefaction may be increased.
다시 도 4를 참조하면, 본 실시예는, 제1 실시예 및 제2 실시예에서 증발가스를 추가적으로 냉각시키기 위한 냉매순환부(300a, 300b)을 폐루프로 구성한 것과 비교하여, 냉매 사이클을 개루프로 구성하였다는 차이점이 있다.Referring to FIG. 4 again, the present embodiment compares the refrigerant cycles 300a and 300b for additionally cooling the boil-off gas in the first and second embodiments to form a closed loop. The difference is that it consists of a loop.
제1 실시예 및 제2 실시예에서는 냉매순환부(300a, 300b)를 폐루프로 구성하여, 냉매압축기(310a, 310b)에 의해 압축된 증발가스는 제2 열교환기(500a, 500b)에서 냉매로 사용될 뿐, 연료수요처로 보내지거나, 재액화 과정을 거칠 수는 없다.In the first and second embodiments, the refrigerant circulation parts 300a and 300b are configured as closed loops, and the boil-off gas compressed by the refrigerant compressors 310a and 310b is cooled in the second heat exchangers 500a and 500b. It cannot be sent to fuel demand or reliquefed.
반면, 본 실시예에서는 냉매 사이클을 개루프로 구성하여, 제2 압축기(122)에 의해 압축된 증발가스가 제1 압축기(120)에 의해 압축된 증발가스와 합류된 후, 합류된 증발가스의 일부는 연료수요처(180)로 보내지고, 다른 일부는 재순환라인(L5)을 따라 제2 열교환기(140) 냉매로 사용되고, 나머지 일부는 복귀라인(L3)을 따라 재액화 과정을 거치게 된다.On the other hand, in the present embodiment, the refrigerant cycle is configured as an open loop, and the boil-off gas compressed by the second compressor 122 is combined with the boil-off gas compressed by the first compressor 120, and then the Some are sent to the fuel demand 180, the other is used as the second heat exchanger 140 refrigerant along the recirculation line (L5), the other part is subjected to the reliquefaction process along the return line (L3).
재순환라인(L5)은, 제1 압축기(120) 하류의 제1 공급라인(L1)으로부터 분기하여 제1 압축기(120) 상류의 제1 공급라인(L1)에 연결되는 라인이다. 제1 공급라인(L1)으로부터 분기된 증발가스가 제2 열교환기(140)로 보내지는 재순환라인(L5) 상에는, 증발가스의 유량 및 개폐를 조절하는 제6 밸브(196)가 설치될 수 있다.The recirculation line L5 is a line branching from the first supply line L1 downstream of the first compressor 120 and connected to the first supply line L1 upstream of the first compressor 120. On the recirculation line L5 through which the boil-off gas branched from the first supply line L1 is sent to the second heat exchanger 140, a sixth valve 196 may be installed to control the flow rate and opening / closing of the boil-off gas. .
냉매 사이클을 개루프로 구성한 본 실시예는, 냉매 사이클을 폐루프로 구성한 제1 실시예 및 제2 실시예에 비하여, 제1 압축기(120) 하류 라인과 제2 압축기(122) 하류 라인이 연결된다는 점에서 큰 차이점이 있다. 즉, 본 실시예는, 제2 압축기(122) 하류의 제2 공급라인(L2)이 제1 압축기(120) 하류의 제1 공급라인(L1)과 연결되어, 제2 압축기(122)에 의해 압축된 증발가스가 제1 압축기(120)에 의해 압축된 증발가스와 합류된 후, 제2 열교환기(140), 연료수요처(180), 또는 제1 열교환기(110)로 보내진다. 본 실시예는, 제1 압축기(120) 하류 라인과 제2 압축기(122) 하류 라인이 연결되는 다른 변형예를 모두 포함한다.In the present embodiment in which the refrigerant cycle is configured as an open loop, the downstream line of the first compressor 120 and the downstream line of the second compressor 122 are connected as compared with the first and second embodiments in which the refrigerant cycle is configured as a closed loop. There is a big difference in that. That is, in the present exemplary embodiment, the second supply line L2 downstream of the second compressor 122 is connected to the first supply line L1 downstream of the first compressor 120 and is connected by the second compressor 122. The compressed boil-off gas is combined with the boil-off gas compressed by the first compressor 120, and then sent to the second heat exchanger 140, the fuel demand 180, or the first heat exchanger 110. This embodiment includes both other variants in which the first compressor 120 downstream line and the second compressor 122 downstream line are connected.
따라서, 본 실시예에 의하면, 선박의 운항 속도가 증가하는 등 연료수요처(180)에서의 요구량이 증가하는 경우에는, 제1 압축기(120)에 의해 압축된 증발가스뿐만 아니라 제2 압축기(122)에 의해 압축된 증발가스도 연료수요처(180)로 보낼 수 있다.Therefore, according to the present embodiment, when the demand amount in the fuel demand unit 180 increases, such as an increase in the operating speed of the ship, the second compressor 122 as well as the boil-off gas compressed by the first compressor 120 may be used. Compressed gas may also be sent to the fuel demand (180).
그러나 일반적으로, 제1 압축기(120) 및 제2 압축기(122)는 연료수요처(180)에서 요구되는 양의 대략 1.2배 정도의 용량을 가지도록 설계하므로, 제1 압축기(120)의 용량을 초과하여 제2 압축기(122)에 의해 압축된 증발가스도 연료수요처(180)로 보내야 하는 경우는 거의 발생하지 않는다. 오히려 저장탱크(T)로부터 배출된 증발가스를 연료수요처(180)에서 모두 소비하지 못하고 재액화하여야 할 증발가스가 증가하여, 많은 양의 증발가스를 재액화시키기 위해 많은 양의 냉매가 필요한 경우가 더 빈번하다.However, in general, since the first compressor 120 and the second compressor 122 are designed to have a capacity of approximately 1.2 times the amount required by the fuel demand 180, the capacity of the first compressor 120 exceeds the capacity of the first compressor 120. Therefore, the case where the boil-off gas compressed by the second compressor 122 also needs to be sent to the fuel demand 180 is hardly generated. Rather, it is not possible to consume all of the evaporated gas discharged from the storage tank T in the fuel demand unit 180, and the amount of the evaporated gas to be reliquefied increases. More frequent
본 실시예에 의하면, 제1 압축기(120)에 의해 압축된 증발가스뿐만 아니라, 제2 압축기(122)에 의해 압축된 증발가스도 제2 열교환기(140)에서의 열교환의 냉매로 사용할 수 있으므로, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급되는 증발가스를, 더 많은 냉매를 이용하여 더 낮은 온도로 냉각시킬 수 있고, 전반적인 재액화 효율 및 재액화량을 증가시킬 수 있으며, 이론적으로는 100% 재액화도 가능하다.According to this embodiment, not only the boil-off gas compressed by the first compressor 120 but also the boil-off gas compressed by the second compressor 122 can be used as a refrigerant for heat exchange in the second heat exchanger 140. After passing through the first heat exchanger 110, the boil-off gas supplied to the second heat exchanger 140 along the return line L3 may be cooled to a lower temperature using more refrigerant, and overall ash Liquefaction efficiency and reliquefaction amount can be increased, theoretically 100% reliquefaction is also possible.
일반적으로 선박에 설치되는 압축기(120, 122)의 용량을 결정할 때에는, 연료수요처(180)에 증발가스를 공급하기 위해 필요한 용량과, 연료수요처(180)에서 모두 소비하지 못하고 남은 증발가스를 재액화시키기 위해 필요한 용량을 모두 감안하게 되는데, 본 실시예에 의하면 제2 압축기(122)를 사용하여 재액화량을 증가시킬 수 있으므로, 재액화에 필요한 용량을 감소시킬 수 있어, 작은 용량의 압축기(120, 122)를 설치할 수 있게 된다. 압축기의 용량을 감소시키면, 장비 설치 비용과 운용 비용을 모두 절감할 수 있는 장점이 있다.In general, when determining the capacity of the compressor (120, 122) installed in the vessel, the capacity required to supply the boil-off gas to the fuel demand (180), and the remaining boil-off gas not consumed by the fuel demand (180) to liquefy Considering all the capacity required to make, but according to the present embodiment can be used to increase the amount of re-liquefaction using the second compressor 122, it is possible to reduce the capacity required for re-liquefaction, so that a small capacity compressor 120 122) can be installed. Reducing the capacity of the compressor has the advantage of reducing both equipment installation and operating costs.
본 실시예에서는, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나지 않은 평상시에도, 제1 밸브(191) 및 제2 밸브(192)뿐만 아니라, 제3 밸브(193) 및 제4 밸브(194)도 열어, 제1 압축기(120), 제1 냉각기(130), 제2 압축기(122), 및 제2 냉각기(132)를 모두 가동시키고, 제1 압축기(120) 또는 제1 냉각기(130)가 고장난 경우에는, 재액화 효율 및 재액화량을 높이는 것을 포기하고, 제1 밸브(191) 및 제2 밸브(192)를 닫아, 제2 압축기(122) 및 제2 냉각기(132)를 통과한 증발가스만으로 시스템을 운용한다.In the present embodiment, not only the first valve 191 and the second valve 192 but also the third valve 193 and the fourth valve, even when the first compressor 120 or the first cooler 130 does not fail. The valve 194 is also opened to operate the first compressor 120, the first cooler 130, the second compressor 122, and the second cooler 132, and to operate the first compressor 120 or the first cooler. In the case where the failure of 130 occurs, the first valve 191 and the second valve 192 are closed and the second compressor 122 and the second cooler 132 are given up to increase the reliquefaction efficiency and the amount of reliquefaction. Operate the system only with boil-off gas that has passed through.
설명의 편의를 위하여, 제1 압축기(120) 및 제1 냉각기(130)가 주된 역할을 하고, 제2 압축기(122)와 제2 냉각기(132)가 보조적인 역할을 하는 것으로 설명하였으나, 제1 압축기(120)와 제2 압축기(122), 제1 냉각기(130)와 제2 냉각기(132)는 동일한 역할을 하며, 하나의 선박에 같은 역할을 하는 압축기 및 냉각기를 두 대 이상 구비하여, 어느 하나가 고장나는 경우에 다른 장비로 대체할 수 있다는 점에서 리던던시(Redundancy) 개념을 만족시키는 것이다. 이하, 동일하다.For convenience of description, it has been described that the first compressor 120 and the first cooler 130 play a main role, and the second compressor 122 and the second cooler 132 play an auxiliary role. The compressor 120, the second compressor 122, the first cooler 130, and the second cooler 132 have the same role, and are provided with two or more compressors and coolers having the same role in one ship. The concept of redundancy is satisfied in that one device can be replaced by another in case of failure. The same applies to the following.
따라서, 제2 압축기(122) 또는 제2 냉각기(132)가 고장나는 경우에도, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나는 경우와 마찬가지로, 재액화 효율 및 재액화량을 높이는 것을 포기하고, 제3 밸브(193) 및 제4 밸브(194)를 닫아, 제1 압축기(120) 및 제1 냉각기(130)를 통과한 증발가스만으로 시스템을 운용한다.Therefore, even when the second compressor 122 or the second cooler 132 fails, similarly to the case where the first compressor 120 or the first cooler 130 fails, the reliquefaction efficiency and the amount of reliquefaction are increased. In this regard, the third valve 193 and the fourth valve 194 are closed to operate the system using only the boil-off gas passed through the first compressor 120 and the first cooler 130.
한편, 저장탱크(T)로부터 배출되는 증발가스의 대부분 또는 전부가 연료수요처(180)의 연료로 사용될 수 있을 정도의 빠른 속도로 선박이 운항되는 경우에는, 재액화할 증발가스의 양이 매우 적거나 없게 된다. 따라서, 선박이 빠른 속도로 운항되는 경우에는 제1 압축기(120) 또는 제2 압축기(122) 중 어느 하나만 구동시킬 수도 있다.On the other hand, when the ship is operated at a speed such that most or all of the boil-off gas discharged from the storage tank T can be used as fuel for the fuel demand unit 180, the amount of the boil-off gas to be reliquefied is very small. With or without. Therefore, when the ship is operating at a high speed, only one of the first compressor 120 or the second compressor 122 may be driven.
제1 압축기(120) 및 제2 압축기(122)는 연료수요처(180)가 요구하는 압력으로 증발가스를 압축시킬 수 있는데, 연료수요처(180)는 증발가스를 연료로 구동되는 엔진, 발전기 등일 수 있다. 일례로 연료수요처(180)가 선박 추진용 엔진인 경우, 제1 압축기(120) 및 제2 압축기(122)는, 증발가스를 대략 10 내지 100 bar의 압력으로 압축시킬 수 있다.The first compressor 120 and the second compressor 122 may compress the boil-off gas to the pressure required by the fuel demand 180, the fuel demand 180 may be an engine, a generator, etc. driven by the boil-off gas as fuel. have. For example, when the fuel demand unit 180 is a marine propulsion engine, the first compressor 120 and the second compressor 122 may compress the boil-off gas to a pressure of approximately 10 to 100 bar.
또한, 제1 압축기(120) 및 제2 압축기(122)는, 연료수요처(180)가 ME-GI 엔진인 경우, 증발가스를 대략 150bar 내지 400bar의 압력으로 압축시킬 수 있고, 연료수요처(180)가 DFDE인 경우, 증발가스를 대략 6.5bar의 압력으로 압축시킬 수 있으며, 연료수요처(180)가 X-DF 엔진인 경우, 증발가스를 대략 16bar의 압력으로 압축시킬 수 있다.In addition, when the fuel demand unit 180 is a ME-GI engine, the first compressor 120 and the second compressor 122 may compress the boil-off gas to a pressure of approximately 150 bar to 400 bar, and the fuel demand unit 180 may be used. In the case of DFDE, the boil-off gas can be compressed to a pressure of approximately 6.5 bar, and if the fuel demand 180 is an X-DF engine, the boil-off gas can be compressed to a pressure of approximately 16 bar.
연료수요처(180)는 여러 종류의 엔진을 포함할 수도 있는데, 일례로 연료수요처(180)가 X-DF 엔진 및 DFDE을 포함하는 경우, 제1 압축기(120) 및 제2 압축기(122)는 X-DF 엔진이 요구하는 압력까지 증발가스를 압축시키고, DFDE의 상류에는 감압장치를 설치하여, X-DF 엔진이 요구하는 압력까지 압축된 증발가스의 일부를 DFDE가 요구하는 압력까지 낮춘 후에 DFDE로 공급할 수도 있다.The fuel demand 180 may include various types of engines. For example, when the fuel demand 180 includes an X-DF engine and a DFDE, the first compressor 120 and the second compressor 122 may be X. -Compresses the boil-off gas to the pressure required by the DF engine, and installs a pressure reducing device upstream of the DFDE, lowers some of the boil-off boiled gas to the pressure required by the DFDE to the pressure required by the DFDE. You can also supply.
그 밖에도, 제1 열교환기(110) 및 제2 열교환기(140)에서의 재액화 효율 및 재액화량을 높이기 위하여, 제1 압축기(120) 또는 제2 압축기(122)에 의해, 증발가스의 압력이 연료수요처(180)가 요구하는 압력을 초과하도록 증발가스를 압축시키고, 연료수요처(180) 상류에는 감압장치를 설치하여, 연료수요처(180)가 요구하는 압력을 초과하도록 압축된 증발가스의 압력을 연료수요처(180)가 요구하는 압력까지 낮춘 후에 연료수요처(180)로 공급할 수도 있다.In addition, in order to increase the reliquefaction efficiency and the amount of reliquefaction in the first heat exchanger 110 and the second heat exchanger 140, the first compressor 120 or the second compressor 122 may provide Compresses the boil-off gas so that the pressure exceeds the pressure required by the fuel demand unit 180, and installs a decompression device upstream of the fuel demand unit 180, so that the pressure of the boil-off gas compressed to exceed the pressure required by the fuel demand unit 180 is The pressure may be lowered to the pressure required by the fuel demand 180 and then supplied to the fuel demand 180.
한편, 제1 압축기(120) 및 제2 압축기(122)는 각각 다단압축기일 수 있다. 도 4에는 하나의 압축기(120 또는 122)에 의해 증발가스를 연료수요처(180)에서 요구하는 압력까지 압축하는 것으로 도시되어 있으나, 제1 압축기(120) 및 제2 압축기(122)가 다단압축기인 경우, 증발가스는 복수개의 압축실린더에 의해 연료수요처(180)에서 요구하는 압력까지 여러 번 압축될 수 있다.Meanwhile, the first compressor 120 and the second compressor 122 may each be a multistage compressor. In FIG. 4, it is shown that one compressor 120 or 122 compresses the boil-off gas to the pressure required by the fuel demand 180, but the first compressor 120 and the second compressor 122 are multistage compressors. In this case, the boil-off gas may be compressed several times to a pressure required by the fuel demand unit 180 by a plurality of compression cylinders.
제1 압축기(120) 및 제2 압축기(122)가 다단압축기일 경우, 제1 압축기(120) 및 제2 압축기(122) 내부에는 복수개의 압축실린더가 직렬로 설치될 수 있고, 복수개의 압축실린더 하류에는 복수개의 냉각기가 각각 설치될 수 있다.When the first compressor 120 and the second compressor 122 are multistage compressors, a plurality of compression cylinders may be installed in series in the first compressor 120 and the second compressor 122, and the plurality of compression cylinders may be installed in series. Downstream, a plurality of coolers may be installed respectively.
본 실시예의 제1 냉각기(130)는, 제1 압축기(120) 하류에 설치되어, 제1 압축기(120)에 의해 압축되어 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시키고, 본 실시예의 제2 냉각기(132)는, 제2 압축기(122) 하류에 설치되어, 제2 압축기(122)에 의해 압축되어 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시킨다. 제1 냉각기(130) 및 제2 냉각기(132)는 외부로부터 유입된 해수, 청수 또는 공기와의 열교환을 통해 증발가스를 냉각시킬 수 있다.The first cooler 130 of this embodiment is installed downstream of the first compressor 120 to cool the boil-off gas compressed by the first compressor 120 to raise not only the pressure but also the temperature, and the second cooler of the present embodiment. 132 is provided downstream of the second compressor 122 to cool the boil-off gas compressed by the second compressor 122 to raise not only the pressure but also the temperature. The first cooler 130 and the second cooler 132 may cool the boil-off gas through heat exchange with seawater, fresh water or air introduced from the outside.
본 실시예의 제2 열교환기(140)는, 제1 열교환기(110)에 의해 냉각된 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급된 증발가스를 추가적으로 냉각시키고, 본 실시예의 냉매감압장치(160)는, 제2 열교환기(140)를 통과한 증발가스를 팽창시킨 후 다시 제2 열교환기(140)로 보낸다.The second heat exchanger 140 of the present embodiment further cools the boil-off gas supplied to the second heat exchanger 140 along the return line L3 after being cooled by the first heat exchanger 110, and performs the present embodiment. The refrigerant reducing device 160 of the example expands the boil-off gas passing through the second heat exchanger 140 and then sends the same to the second heat exchanger 140.
즉, 제2 열교환기(140)는, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급되는 증발가스를, 냉매감압장치(160)에 의해 팽창된 증발가스를 냉매로 열교환시켜, 추가적으로 냉각시킨다.That is, the second heat exchanger 140 passes through the first heat exchanger 110 and then supplies the boil-off gas supplied to the second heat exchanger 140 along the return line L3 to the refrigerant pressure reducing device 160. The evaporated gas thus expanded is heat-exchanged with a refrigerant and further cooled.
본 실시예의 냉매감압장치(160)는 유체의 압력을 낮추기 위한 다양한 수단일 수 있고, 냉매감압장치(160)를 통과하기 직전의 유체의 상태 및 통과한 직후의 유체의 상태는 시스템의 운용 조건에 따라 달라질 수 있다. 단, 냉매감압장치(160)가 팽창기인 경우, 냉매감압장치(160)의 물리적 손상을 방지하기 위하여, 냉매감압장치(160)를 통과하기 직전의 유체 및 통과한 직후의 유체는 기체상으로 유지되는 것이 바람직하다. 이하, 동일하다.The refrigerant pressure reducing device 160 of the present embodiment may be various means for lowering the pressure of the fluid, and the state of the fluid immediately before passing through the refrigerant pressure reducing device 160 and the state of the fluid immediately after the passage are dependent on the operating conditions of the system. It may vary. However, when the refrigerant pressure reducing device 160 is an expander, in order to prevent physical damage of the refrigerant pressure reducing device 160, the fluid immediately before passing through the refrigerant pressure reducing device 160 and the fluid immediately after passing are maintained in the gas phase. It is preferable to be. The same applies to the following.
냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 열교환의 냉매로 사용되는 증발가스는, 제1 압축기(120)에 의해 압축된 증발가스가 제2 압축기(122)에 의해 압축된 증발가스와 합류된 후, 합류된 증발가스의 일부가 재순환라인(L5)을 따라 제2 열교환기(140)로 공급되어, 제2 열교환기(140)에서 냉매감압장치(160)를 통과한 증발가스를 냉매로 열교환되어 냉각된 후 냉매감압장치(160)로 공급된 것이다.After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant for heat exchange in the second heat exchanger 140 is compressed by the second compressor 122 by the boil-off gas compressed by the first compressor 120. After joining with the evaporated gas, a part of the combined evaporated gas is supplied to the second heat exchanger 140 along the recirculation line (L5), passing through the refrigerant pressure reducing device 160 in the second heat exchanger (140) The evaporated gas is cooled by heat exchange with a refrigerant and then supplied to the refrigerant decompression device 160.
또한, 제1 공급라인(L1)으로부터 재순환라인(L5)을 따라 제2 열교환기(140)로 공급되는 증발가스는, 제2 열교환기(140)에서 1차로 냉각되고 냉매감압장치(160)에 의해 추가적으로 냉각된 후 다시 제2 열교환기(140)로 보내져 냉매로 사용되는 것이다.In addition, the boil-off gas supplied from the first supply line (L1) to the second heat exchanger 140 along the recycle line (L5) is first cooled in the second heat exchanger (140) to the refrigerant pressure reducing device (160). After the additional cooling is sent to the second heat exchanger 140 is used as a refrigerant.
즉, 제1 압축기(120)에 의해 압축된 증발가스가 제2 압축기(122)에 의해 압축된 증발가스와 합류된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 공급되는 흐름;과, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급되는 증발가스;는 둘 다, 냉매감압장치(160)를 통과한 증발가스를 냉매로 하여, 열교환되어 냉각된다.That is, the flow in which the boil-off gas compressed by the first compressor 120 is joined to the boil-off gas compressed by the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5; And, after passing through the first heat exchanger 110, the evaporated gas supplied to the second heat exchanger 140 along the return line (L3); both, the refrigerant evaporated gas passing through the refrigerant pressure reducing device 160 The heat exchanger is cooled.
본 실시예의 제1 감압장치(150)는, 복귀라인(L3) 상에 설치되어, 제1 열교환기(110) 및 제2 열교환기(140)에 의해 냉각된 증발가스를 팽창시킨다. 제1 압축기(120)에 의해 압축된 증발가스는, 제2 압축기(122)에 의해 압축된 증발가스와 합류된 후 일부 분기하여, 복귀라인(L3)을 따라 제1 열교환기(110), 제2 열교환기(140) 및 제1 감압장치(150)를 통과하며 일부 또는 전부가 재액화된다.The first pressure reducing device 150 of the present embodiment is installed on the return line L3 to expand the boil-off gas cooled by the first heat exchanger 110 and the second heat exchanger 140. The boil-off gas compressed by the first compressor 120 merges with the boil-off gas compressed by the second compressor 122 and partially branches the first boil-off heat exchanger 110 and the first heat exchanger along the return line L3. 2 is passed through the heat exchanger 140 and the first pressure reducing device 150 and part or all of it is reliquefied.
제1 감압장치(150)는, 증발가스를 팽창시켜 냉각시킬 수 있는 모든 수단을 포함하며, 줄-톰슨(Joule-Thomson) 밸브 등의 팽창밸브, 또는 팽창기일 수 있다.The first pressure reducing device 150 includes all means capable of expanding and cooling the boil-off gas and may be an expansion valve such as a Joule-Thomson valve or an expander.
본 실시예의 선박은, 제1 감압장치(150) 하류의 복귀라인(L3) 상에 설치되며 제1 감압장치(150)으로부터 배출되는 기액 혼합물을 기체와 액체로 분리하는, 기액분리기(170)를 포함할 수 있다.The vessel of the present embodiment, the gas-liquid separator 170 is installed on the return line (L3) downstream of the first decompression device 150 and separates the gas-liquid mixture discharged from the first decompression device 150 into a gas and a liquid. It may include.
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우, 제1 감압장치(150)를 통과한 액체 또는 기액혼합 상태의 증발가스는 바로 저장탱크(T)로 보내진다.When the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or gaseous gas in the gas-liquid mixed state passing through the first decompression device 150 is directly sent to the storage tank (T).
본 실시예의 선박이 기액분리기(170)를 포함하는 경우, 제1 감압장치(150)를 통과한 증발가스는 기액분리기(170)로 보내져, 기체상과 액체상이 분리된다. 기액분리기(170)에 의해 분리된 액체는 복귀라인(L3)을 따라 저장탱크(T)로 복귀하고, 기액분리기(170)에 의해 분리된 기체는, 기액분리기(170)로부터 제1 열교환기(110) 상류의 제1 공급라인(L1)까지 연장되는 기체배출라인(L4)을 따라, 제1 열교환기(110)으로 공급된다.When the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first decompression device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
본 실시예의 선박이 기액분리기(170)를 포함하는 경우, 기액분리기(170)에 의해 분리되어 저장탱크(T)로 보내지는 액체의 유량을 조절하는 제7 밸브(197); 및 기액분리기(170)에 의해 분리되어 제1 열교환기(110)로 보내지는 기체의 유량을 조절하는 제8 밸브(198);를 더 포함할 수 있다.When the vessel of the present embodiment includes a gas-liquid separator 170, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
본 실시예의 제1 내지 제8 밸브, 및 제11 밸브는(191, 192, 193, 194, 195, 196, 197, 198, 203)는, 시스템 운용 상황을 사람이 직접 판단하여 수동으로 조절될 수도 있고, 미리 설정된 값에 의해 개폐되도록 자동으로 조절될 수도 있다.The first to eighth valves and the eleventh valves of the present exemplary embodiment 191, 192, 193, 194, 195, 196, 197, 198, and 203 may be manually adjusted by a person directly determining a system operating situation. It may be automatically adjusted to open and close by a preset value.
본 발명의 일 실시예에 따른 증발가스 재액화를 위한 장치의 작용을 용이하게 설명하기 위해 증발가스의 주요 흐름을 정의한다. 저장탱크(T)에서 발생하는 증발가스와 기액분리기(170)에서 배출되는 기체가 제1 열교환기(110)으로 공급되는 흐름을 제1 흐름(100), 제1 열교환기(110)에서 제1 압축기(120) 또는 제2 압축기(122)로 공급된 후에 제1 압축기(120) 또는 제2 압축기(122)로부터 배출되어 연료수요처(180)로 공급되는 흐름을 제2 흐름(102), 제1 압축기(120) 및 제2 압축기(122) 하류에서 제2 흐름(102)으로부터 분기하여 제2 열교환기(140)로 공급되는 흐름을 제3 흐름(104), 제1 압축기(120) 및 제2 압축기(122) 하류에서 제2 흐름(102)으로부터 분기하여 제1 열교환기(110)으로 공급되는 흐름을 제4 흐름(106), 제1 열교환기(110)으로부터 제2 열교환기(140)로 공급되는 흐름을 제5 흐름(108)으로 정의한다. 제1 흐름(100)은 제1 열교환기(110)을 통과하면서 제2 흐름(102)이 되고, 제4 흐름(106)은 제1 열교환기(110)을 통과하면서 제5 흐름(108)이 된다.The main flow of the boil-off gas is defined to easily explain the operation of the apparatus for boil-off gas reliquefaction according to an embodiment of the present invention. The evaporation gas generated in the storage tank T and the gas discharged from the gas-liquid separator 170 are supplied to the first heat exchanger 110 by the first flow 100 and the first heat exchanger 110 by the first flow. After being supplied to the compressor 120 or the second compressor 122, the flow discharged from the first compressor 120 or the second compressor 122 to the fuel demand 180 is supplied to the second flow 102 and the first compressor 122. Downstream of the compressor 120 and the second compressor 122, flows branching from the second flow 102 to the second heat exchanger 140 are supplied to the third flow 104, the first compressor 120, and the second. Downstream of the compressor 122, a flow branched from the second flow 102 and supplied to the first heat exchanger 110 from the fourth flow 106 and the first heat exchanger 110 to the second heat exchanger 140. The supplied flow is defined as the fifth flow 108. The first flow 100 passes through the first heat exchanger 110 and becomes the second flow 102, and the fourth flow 106 passes through the first heat exchanger 110 and the fifth flow 108 passes through the first heat exchanger 110. do.
이하, 도 4를 참조하여 본 발명의 일 실시예에 따른 증발가스 재액화를 위한 장치의 작용을 설명한다.Hereinafter, with reference to Figure 4 describes the operation of the apparatus for re-liquefaction of the boil-off gas according to an embodiment of the present invention.
액체 상태의 액화가스를 저장하는 저장탱크(T)에서 생성되는 기체상태의 증발가스는 제1 열교환기(110)로 공급된다. 이때, 저장탱크(T)에서 생성되는 기체 상태의 증발가스는, 시스템 작동 후 일정 시간이 경과한 후 기액분리기(170)에서 배출되는 기체 상태의 증발가스와 만나 제1 흐름(100)을 형성하게 된다. 궁극적으로 제1 열교환기(110)로 공급되는 증발가스는 제1 흐름(100)이다.The gaseous evaporated gas generated in the storage tank T storing the liquid liquefied gas is supplied to the first heat exchanger 110. At this time, the gaseous evaporated gas generated in the storage tank (T) meets the gaseous evaporated gas discharged from the gas-liquid separator 170 after a predetermined time after the system operation to form the first flow (100). do. Ultimately, the boil-off gas supplied to the first heat exchanger 110 is the first flow 100.
제1 열교환기(110)는 제1 흐름(100)이 가지고 있는 냉열을 회수하여 다른 증발가스를 냉각시키는 역할을 한다. 즉, 제1 열교환기(110)는, 제1 흐름(100)이 갖고 있는 냉열을 회수하여, 제2 흐름(102) 중 제1 열교환기(110)으로 다시 공급되는 흐름, 즉, 제4 흐름(106)에 회수한 냉열을 전달한다.The first heat exchanger 110 recovers the cold heat of the first flow 100 and cools other boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the first flow 100 and is supplied again to the first heat exchanger 110 of the second flow 102, that is, the fourth flow. The recovered cold heat is transferred to 106.
따라서, 제1 열교환기(110)에서는 제1 흐름(100)과 제4 흐름(106) 간의 열교환이 일어나게 되어, 제1 흐름(100)은 가열되고 제4 흐름(106)은 냉각된다. 가열된 제1 흐름(100)은 제2 흐름(102)이 되고, 냉각된 제4 흐름(106)은 제5 흐름(108)이 된다.Thus, in the first heat exchanger 110, heat exchange occurs between the first flow 100 and the fourth flow 106, such that the first flow 100 is heated and the fourth flow 106 is cooled. The heated first flow 100 becomes the second flow 102 and the cooled fourth flow 106 becomes the fifth flow 108.
제1 열교환기(110)에서 배출되는 제2 흐름(102)은, 제1 압축기(120) 또는 제2 압축기(122)로 공급되어, 제1 압축기(120) 또는 제2 압축기(122)에 의해 압축된다.The second stream 102 discharged from the first heat exchanger 110 is supplied to the first compressor 120 or the second compressor 122, and is supplied by the first compressor 120 or the second compressor 122. Is compressed.
제1 압축기(120)에 의해 압축된 증발가스와 제2 압축기(122)에서 압축된 증발가스가 합류된 제2 흐름(102)은, 일부는 제3 흐름(104)으로서 제2 열교환기(140)에 냉매로 공급되고, 다른 일부는 제4 흐름(106)으로서 제1 열교환기(110)에 공급되어 냉각되고, 나머지 일부는 연료수요처(180)에 공급된다.The second flow 102, in which the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the second compressor 122 joins, is part of the second heat exchanger 140 as the third flow 104. ) Is supplied as a refrigerant, and the other part is supplied to the first heat exchanger 110 as a fourth flow 106 to be cooled, and the other part is supplied to the fuel demand 180.
제2 열교환기(140)로 공급되는 제3 흐름(104)은, 제2 열교환기(140)로부터 배출되고 냉매감압장치(160)에서 팽창된 후 다시 제2 열교환기(140)로 공급된다. 이 때, 1차로 제2 열교환기(140)로 공급된 제3 흐름(104)은, 냉매감압장치(160)에서 팽창된 후, 다시 제2 열교환기(140)로 공급되는 제3 흐름(104)과 열교환되어 냉각된다. 냉매감압장치(160) 및 제2 열교환기(140)를 통과한 제3 흐름(104)은, 제1 열교환기(110)로부터 배출되는 제2 흐름(102)과 합류하여, 제1 압축기(120) 또는 제2 압축기(122)로 공급된다.The third flow 104 supplied to the second heat exchanger 140 is discharged from the second heat exchanger 140, expanded in the refrigerant pressure reducing device 160, and then supplied to the second heat exchanger 140. At this time, the third flow 104, which is primarily supplied to the second heat exchanger 140, is expanded by the refrigerant pressure reducing device 160, and then the third flow 104 is supplied to the second heat exchanger 140 again. Heat exchanger) to cool. The third flow 104 passing through the refrigerant pressure reducing device 160 and the second heat exchanger 140 joins the second flow 102 discharged from the first heat exchanger 110 to form the first compressor 120. ) Or to the second compressor 122.
제1 열교환기(110)에서 제1 흐름(100)과 열교환하여 냉각된 제4 흐름(106)은, 제5 흐름(108)이 되어 제2 열교환기(140)로 공급된다. 제2 열교환기(140)로 공급된 제5 흐름(108)은, 냉매감압장치(160)를 통과한 제3 흐름(104)과 열교환되어 냉각된 후, 제1 감압장치(150)을 통과하며 팽창된다. 제1 감압장치(150)을 통과한 제5 흐름(108)은 기체와 액체가 혼합된, 기액 혼합물 상태가 된다.The fourth flow 106 cooled by heat-exchanging with the first flow 100 in the first heat exchanger 110 becomes the fifth flow 108 and is supplied to the second heat exchanger 140. The fifth flow 108 supplied to the second heat exchanger 140 is cooled by heat exchange with the third flow 104 passed through the refrigerant pressure reducing device 160, and then passes through the first pressure reducing device 150. Swell. The fifth flow 108 through the first pressure reducing device 150 is in a gas-liquid mixture, in which gas and liquid are mixed.
기액 혼합물 상태의 제5 흐름(108)은, 바로 저장탱크(T)로 보내지거나, 기액분리기(170)를 통과하면서 기체와 액체로 분리된다. 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 공급되며, 기액분리기(170)에 의해 분리된 기체는 다시 제1 열교환기(110)으로 공급되어 상기 과정들을 반복하게 된다.The fifth stream 108 in the gas-liquid mixture is directly sent to the storage tank T or separated into gas and liquid while passing through the gas-liquid separator 170. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T, and the gas separated by the gas-liquid separator 170 is supplied to the first heat exchanger 110 to repeat the above processes.
도 5는 본 발명의 제4 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.5 is a configuration diagram schematically showing a boil-off gas treatment system according to a fourth embodiment of the present invention.
도 5에 도시된 제4 실시예의 선박은, 도 4에 도시된 제3 실시예의 선박에 비해, 제2 공급라인(L2)에 설치되는 추가압축기(124) 및 추가냉각기(134)와, 복귀라인(L3)에 설치되는 추진압축기(126) 및 추진냉각기(136)를 더 포함한다는 점과, 제9 밸브(201), 제10 밸브(202), 제12 밸브(205) 및 제1 추가라인(L6)을 더 포함하고, 증발가스가 흐르는 일부 라인을 수정하여, 냉매 사이클을 폐루프로 운용할 수도 있고 개루프로 운용할 수도 있도록 구성하였다는 점에서 차이점이 존재하며, 이하에서는 차이점을 위주로 설명한다. 전술한 제3 실시예의 선박과 동일한 부재에 대하여는 자세한 설명은 생략한다.The ship of the fourth embodiment shown in FIG. 5 has an additional compressor 124 and an additional cooler 134 installed in the second supply line L2 and a return line, compared to the ship of the third embodiment shown in FIG. 4. Further comprising a propulsion compressor 126 and the propulsion cooler 136 installed in (L3), and the ninth valve 201, the tenth valve 202, the twelfth valve 205 and the first additional line ( L6) is further included, and a difference exists in that the refrigerant cycle can be operated in a closed loop or in an open loop by modifying some lines through which the evaporated gas flows. do. Detailed descriptions of the same members as those of the ship of the third embodiment are omitted.
도 5를 참조하면, 본 실시예의 선박은, 제3 실시예와 마찬가지로, 제1 열교환기(110), 제1 밸브(191), 제1 압축기(120), 제1 냉각기(130), 제2 밸브(192), 제3 밸브(193), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194), 제2 열교환기(140), 냉매감압장치(160), 및 제1 감압장치(150)를 포함한다.Referring to FIG. 5, the vessel of the present embodiment, like the third embodiment, includes the first heat exchanger 110, the first valve 191, the first compressor 120, the first cooler 130, and the second. Valve 192, third valve 193, second compressor 122, second cooler 132, fourth valve 194, second heat exchanger 140, refrigerant pressure reducing device 160, and 1 includes a decompression device 150.
본 실시예의 저장탱크(T)는, 제3 실시예와 마찬가지로, 내부에 액화천연가스, 액화에탄가스 등의 액화가스를 저장하며, 내부 압력이 일정 압력 이상이 되면 증발가스를 외부로 배출시킨다. 저장탱크(T)로부터 배출되는 증발가스는 제1 열교환기(110)로 보내진다.As in the third embodiment, the storage tank T of the present embodiment stores the liquefied gas such as liquefied natural gas and liquefied ethane gas inside, and discharges the boil-off gas to the outside when the internal pressure is higher than the predetermined pressure. The boil-off gas discharged from the storage tank T is sent to the first heat exchanger 110.
본 실시예의 제1 열교환기(110)는, 제3 실시예와 마찬가지로, 저장탱크(T)로부터 배출된 증발가스를 냉매로 사용하여, 복귀라인(L3)을 따라 제1 열교환기(110)로 보내진 증발가스를 냉각시킨다. 즉, 제1 열교환기(110)는, 저장탱크(T)로부터 배출된 증발가스의 냉열을 회수하여, 회수한 냉열을 복귀라인(L3)을 따라 제1 열교환기(110)로 보내진 증발가스에 공급한다. 복귀라인(L3) 상에는 증발가스의 유량 및 개폐를 조절하는 제5 밸브(195)가 설치될 수 있다.As in the third embodiment, the first heat exchanger 110 according to the present embodiment uses the evaporated gas discharged from the storage tank T as the refrigerant, and returns to the first heat exchanger 110 along the return line L3. Cool the sent boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the boil-off gas discharged from the storage tank T, and recovers the collected cold heat to the boil-off gas sent to the first heat exchanger 110 along the return line L3. Supply. A fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
본 실시예의 제1 압축기(120)는, 제3 실시예와 마찬가지로, 제1 공급라인(L1) 상에 설치되어 저장탱크(T)로부터 배출된 증발가스를 압축시키고, 본 실시예의 제2 압축기(122)는, 제3 실시예와 마찬가지로, 제2 공급라인(L2) 상에 제1 압축기(120)와 병렬로 설치되어 저장탱크(T)로부터 배출된 증발가스를 압축시킨다. 제1 압축기(120)와 제2 압축기(122)는, 동일한 성능의 압축기일 수 있고, 각각 다단압축기일 수 있다.The first compressor 120 of the present embodiment, like the third embodiment, is installed on the first supply line L1 to compress the boil-off gas discharged from the storage tank T, and the second compressor of the present embodiment ( As in the third embodiment, 122 is installed in parallel with the first compressor 120 on the second supply line L2 to compress the boil-off gas discharged from the storage tank T. The first compressor 120 and the second compressor 122 may be compressors of the same performance, and may each be a multistage compressor.
본 실시예의 제1 압축기(120) 및 제2 압축기(122)는, 제3 실시예와 마찬가지로, 연료수요처(180)가 요구하는 압력으로 증발가스를 압축시킬 수 있다. 또한, 연료수요처(180)가 여러 종류의 엔진을 포함하는 경우에는, 더 높은 압력을 요구하는 엔진(이하, '고압 엔진'이라고 함.)의 요구 압력에 맞추어 증발가스를 압축한 후 일부는 고압 엔진으로 공급하고, 다른 일부는 더 낮은 압력을 요구하는 엔진(이하, '저압 엔진'이라고 함.) 상류에 설치된 감압장치에 의해 감압시킨 후 저압 엔진으로 공급할 수 있다. 그 밖에도, 제1 열교환기(110) 및 제2 열교환기(140)에서의 재액화 효율 및 재액화량을 높이기 위하여, 증발가스를 제1 압축기(120) 또는 제2 압축기(122)에 의해 연료수요처(180)가 요구하는 압력 이상의 고압으로 압축시키고, 연료수요처(180) 상류에는 감압장치를 설치하여, 고압으로 압축된 증발가스의 압력을 연료수요처(180)가 요구하는 압력까지 낮춘 후에 연료수요처(180)로 공급할 수도 있다.Like the third embodiment, the first compressor 120 and the second compressor 122 of the present embodiment can compress the boil-off gas to the pressure required by the fuel demand 180. In addition, when the fuel demand unit 180 includes several types of engines, some of the high pressures are compressed after compressing the boil-off gas in accordance with a required pressure of an engine requiring higher pressure (hereinafter, referred to as a 'high pressure engine'). It can be supplied to the engine, and the other part can be supplied to the low pressure engine after being depressurized by a pressure reducing device installed upstream of the engine requiring a lower pressure (hereinafter referred to as a 'low pressure engine'). In addition, in order to increase the reliquefaction efficiency and the amount of reliquefaction in the first heat exchanger 110 and the second heat exchanger 140, the boil-off gas is fueled by the first compressor 120 or the second compressor 122. It is compressed to a high pressure higher than the pressure required by the customer 180, and a pressure reducing device is provided upstream of the fuel demand 180 to lower the pressure of the boiled gas compressed to a high pressure to the pressure required by the fuel demand 180, and then the fuel demand. 180 may be supplied.
본 실시예의 선박은, 제3 실시예와 마찬가지로, 연료수요처(180) 상류에 설치되어, 연료수요처(180)로 보내지는 증발가스의 유량 및 개폐를 조절하는 제11 밸브(203)를 더 포함할 수 있다.The vessel of this embodiment, like the third embodiment, further includes an eleventh valve 203 which is provided upstream of the fuel demand unit 180 and regulates the flow rate and opening and closing of the boil-off gas sent to the fuel demand unit 180. Can be.
본 실시예의 선박은, 제3 실시예와 마찬가지로, 제2 압축기(122)에 의해 압축된 증발가스를 제2 열교환기(140)에서 증발가스를 추가적으로 냉각시키는 냉매로 사용하므로, 재액화 효율 및 재액화량을 높일 수 있다.The vessel of this embodiment, like the third embodiment, uses the boil-off gas compressed by the second compressor 122 as a refrigerant for further cooling the boil-off gas in the second heat exchanger 140, so that the re-liquefaction efficiency and re- The amount of liquefaction can be increased.
본 실시예의 제1 냉각기(130)는, 제3 실시예와 마찬가지로, 제1 압축기(120) 하류에 설치되어, 제1 압축기(120)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시키며, 본 실시예의 제2 냉각기(132)는, 제3 실시예와 마찬가지로, 제2 압축기(122) 하류에 설치되어, 제2 압축기(122)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시킨다.The first cooler 130 of the present embodiment, like the third embodiment, is installed downstream of the first compressor 120 and cools the evaporated gas that passes not only the pressure but also the temperature through the first compressor 120, Similar to the third embodiment, the second cooler 132 of the present embodiment is installed downstream of the second compressor 122 to cool the evaporated gas that passes not only the pressure but also the temperature through the second compressor 122.
본 실시예의 제2 열교환기(140)는, 제3 실시예와 마찬가지로, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되어, 제1 열교환기(110)에 의해 냉각된 증발가스를 추가적으로 냉각시킨다.As in the third embodiment, the second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 and is cooled by the first heat exchanger 110. Cool additionally.
본 실시예에 의하면, 제3 실시예와 마찬가지로, 저장탱크(T)로부터 배출된 증발가스가 제1 열교환기(110)뿐만 아니라 제2 열교환기(140)에서도 추가적으로 냉각되어, 더 온도가 낮은 상태로 제1 감압장치(150)로 공급될 수 있으므로, 재액화 효율 및 재액화량이 높아지게 된다.According to this embodiment, as in the third embodiment, the boil-off gas discharged from the storage tank T is additionally cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, so that the temperature is lower. Furnace can be supplied to the first decompression device 150, the re-liquefaction efficiency and the amount of re-liquefaction is increased.
본 실시예의 냉매감압장치(160)는, 제3 실시예와 마찬가지로, 제2 열교환기(140)를 통과한 증발가스를 팽창시킨 후 다시 제2 열교환기(140)로 보낸다.The refrigerant pressure reducing device 160 according to the present embodiment expands the boil-off gas passed through the second heat exchanger 140 and sends it to the second heat exchanger 140 in the same manner as in the third embodiment.
본 실시예의 제1 감압장치(150)는, 제3 실시예와 마찬가지로, 복귀라인(L3) 상에 설치되어, 제1 열교환기(110) 및 제2 열교환기(140)에 의해 냉각된 증발가스를 팽창시킨다. 본 실시예의 제1 감압장치(150)는, 증발가스를 팽창시켜 냉각시킬 수 있는 모든 수단을 포함하며, 줄-톰슨(Joule-Thomson) 밸브 등의 팽창밸브, 또는 팽창기일 수 있다.As in the third embodiment, the first pressure reducing device 150 of the present embodiment is installed on the return line L3 and is cooled by the first heat exchanger 110 and the second heat exchanger 140. Inflate. The first pressure reducing device 150 of the present embodiment includes all means capable of expanding and cooling the boil-off gas, and may be an expansion valve such as a Joule-Thomson valve or an expander.
본 실시예의 선박은, 제3 실시예와 마찬가지로, 제1 감압장치(150) 하류의 복귀라인(L3) 상에 설치되며 제1 감압장치(150)으로부터 배출되는 기액 혼합물을 기체와 액체로 분리하는, 기액분리기(170)를 포함할 수 있다.The vessel of the present embodiment, like the third embodiment, is installed on the return line L3 downstream of the first pressure reducing device 150 and separates the gas-liquid mixture discharged from the first pressure reducing device 150 into gas and liquid. , Gas-liquid separator 170 may be included.
제3 실시예와 마찬가지로, 본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는 제1 감압장치(150)를 통과한 액체 또는 기액혼합 상태의 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는 제1 감압장치(150)를 통과한 증발가스는 기액분리기(170)로 보내져, 기체상과 액체상이 분리된다. 기액분리기(170)에 의해 분리된 액체는 복귀라인(L3)을 따라 저장탱크(T)로 복귀하고, 기액분리기(170)에 의해 분리된 기체는, 기액분리기(170)로부터 제1 열교환기(110) 상류의 제1 공급라인(L1)까지 연장되는 기체배출라인(L4)을 따라, 제1 열교환기(110)으로 공급된다.As in the third embodiment, when the vessel of this embodiment does not include the gas-liquid separator 170, the liquid or gaseous-mixed evaporated gas that has passed through the first decompression device 150 is directly sent to the storage tank T. When the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first pressure reducing device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
본 실시예의 선박이 기액분리기(170)를 포함하는 경우, 제3 실시예와 마찬가지로, 기액분리기(170)에 의해 분리되어 저장탱크(T)로 보내지는 액체의 유량을 조절하는 제7 밸브(197); 및 기액분리기(170)에 의해 분리되어 제1 열교환기(110)로 보내지는 기체의 유량을 조절하는 제8 밸브(198);를 더 포함할 수 있다.When the vessel of the present embodiment includes the gas-liquid separator 170, like the third embodiment, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T) ); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
단, 본 실시예의 선박은, 제3 실시예와는 달리, 제2 공급라인(L2) 상에 설치되는 추가압축기(124); 추가압축기(124) 하류에 설치되는 추가냉각기(134); 복귀라인(L3) 상에 설치되는 추진압축기(126); 추진압축기(126) 하류에 설치되는 추진냉각기(136); 재순환라인(L5)과 제2 공급라인(L2) 사이를 연결하는 제1 추가라인(L6); 재순환라인(L5) 상에 설치되는 제9 밸브(201); 제1 추가라인(L6) 상에 설치되는 제10 밸브(202); 및 제2 공급라인(L2)과 제2 열교환기(140) 사이의 재순환라인(L5) 상에 설치되는 제12 밸브(205);를 더 포함한다.However, the ship of this embodiment, unlike the third embodiment, the additional compressor 124 is installed on the second supply line (L2); An additional cooler 134 installed downstream of the additional compressor 124; A propulsion compressor 126 installed on the return line L3; A propulsion cooler 136 installed downstream of the propulsion compressor 126; A first additional line L6 connecting between the recirculation line L5 and the second supply line L2; A ninth valve 201 installed on the recirculation line L5; A tenth valve 202 installed on the first additional line L6; And a twelfth valve 205 installed on the recirculation line L5 between the second supply line L2 and the second heat exchanger 140.
또한, 본 실시예의 선박은, 제6 밸브를 선택적으로 포함하는 제3 실시예와는 달리, 제1 공급라인(L1)으로부터 분기된 증발가스가 제2 열교환기(140)로 보내지는 재순환라인(L5) 상에 설치되어, 증발가스의 유량 및 개폐를 조절하는 제6 밸브(196)를 필수적으로 포함한다.In addition, the ship of the present embodiment, unlike the third embodiment, which selectively includes a sixth valve, the recirculation line (2) in which the boil-off gas branched from the first supply line (L1) is sent to the second heat exchanger 140 ( It is provided on the L5), and essentially includes a sixth valve (196) for controlling the flow rate and opening and closing of the boil-off gas.
본 실시예의 추가압축기(124)는, 제2 공급라인(L2) 상의 제2 압축기(122) 상류 또는 하류에 설치되고, 제2 압축기(122)보다 더 작은 용량을 가질 수 있다. 추가압축기(124)는, 냉매감압장치(160)가 유체를 팽창시키면서 생산하는 동력에 의해 구동될 수 있으며, 추가압축기(124)의 용량은, 냉매감압장치(160)가 생산하는 동력에 의해 구동될 수 있는 용량일 수 있다. 본 실시예에서는 냉매감압장치(160)가 유체를 팽창시키면서 생산하는 동력을 추가압축기(124)에서 사용하는 경우를 예로 들어 설명하나, 냉매감압장치(160)가 생산하는 동력을 제1 압축기(120)나 제2 압축기(122)에서 사용하도록 시스템을 구성할 수도 있다.The additional compressor 124 of the present embodiment may be installed upstream or downstream of the second compressor 122 on the second supply line L2 and may have a smaller capacity than the second compressor 122. The additional compressor 124 may be driven by the power produced by the refrigerant pressure reducing device 160 while expanding the fluid, and the capacity of the additional compressor 124 may be driven by power generated by the refrigerant pressure reducing device 160. It may be a dose that can be. In this embodiment, a case in which the refrigerant reducing device 160 uses the power generated by expanding the fluid in the additional compressor 124 will be described as an example, but the power generated by the refrigerant reducing device 160 will be described as the first compressor 120. Or the system may be configured for use in the second compressor 122.
압축기의 종류에는, 고속으로 날개차를 회전시켜 원심력에 의한 에너지로 가스를 압축시키는 원심 압축기(Centrifugal Compressor), 실리더 내 피스톤의 왕복 운동으로 가스를 압축시키는 왕복동 압축기(Reciprocating Compressor), 2개의 로터의 맞물림에 의하여 가스를 압축시키는 스크류 압축기(Screw Compressor) 등이 있는데, 이 중 왕복동 압축기와 스크류 압축기는, 일정한 용적 속에 흡입된 기체를 압축시키는 용적형 압축기(Positive Displacement Compressor)에 속한다.Compressors include centrifugal compressors that rotate the vanes at high speed to compress gas with energy from centrifugal force, reciprocating compressors that compress the gas by reciprocating the piston in the cylinder, and two rotors. There is a screw compressor (Compressor) for compressing the gas by the engagement of the reciprocating compressor and the screw compressor, of which belongs to the volumetric compressor (Positive Displacement Compressor) for compressing the gas sucked in a constant volume.
본 실시예의 제1 압축기(120) 및 제2 압축기(122)는 용적형 압축기인 것이 바람직하고, 추가압축기(124)는 원심형 압축기인 것이 바람직한데, 추가압축기(124)가 제2 압축기(122) 하류에 설치되는 경우, 제2 압축기(122)는 제1 압축기(120)와 동일한 유량을 압축시키므로, 제2 공급라인(L2)을 통과한 증발가스의 질량유량은 동일하고 압력만 높아지는 효과가 발생한다. 그러나, 추가압축기(124)가 제2 압축기(122) 상류에 설치되는 경우에는, 추가압축기(124)에 의해 압축되어 밀도가 높아진 증발가스가 제2 압축기(122)에 공급되므로, 제2 압축기(122)에 공급되는 증발가스의 질량유량을 증가시킬 수 있다.Preferably, the first compressor 120 and the second compressor 122 of the present embodiment are volumetric compressors, and the additional compressor 124 is preferably a centrifugal compressor, and the additional compressor 124 is the second compressor 122. When installed downstream, the second compressor 122 compresses the same flow rate as the first compressor 120, so that the mass flow rate of the boil-off gas passing through the second supply line L2 is the same and only the pressure is increased. Occurs. However, when the additional compressor 124 is installed upstream of the second compressor 122, the second compressor 122 is supplied with the boil-off gas which is compressed by the additional compressor 124 and has a high density. The mass flow rate of the boil-off gas supplied to 122 can be increased.
즉, 추가압축기(124)가 제2 압축기(122) 상류에 설치되는 경우, 저장탱크(T)로부터 배출된 후 제2 공급라인(L2)으로 공급된 증발가스는 추가압축기(124)에 의해 압축되며 밀도가 높아지므로, 제2 압축기(122)에 같은 유량의 증발가스가 공급되어도 제2 압축기(122)로 공급되는 증발가스의 질량은 더 커지게 된다. 결국, 제2 압축기(122)에 의해 압축된 후 제2 열교환기(140)에서 냉매로 사용되는 유체의 질량이 더 커지므로, 제2 열교환기(140)에서의 재액화 효율과 재액화량을 증가시킬 수 있다. 추가압축기(124)가 제2 압축기(122) 상류에 설치되는 경우, 본 실시예를 폐루프 및 독립 개루프로 운용할 수 있을 뿐만 아니라, 제2 압축기(122)의 출구 압력을 제1 압축기(120)의 출구 압력과 동일하게 조절하여 개루프로 운용할 수도 있다.That is, when the additional compressor 124 is installed upstream of the second compressor 122, the boil-off gas supplied from the storage tank T and supplied to the second supply line L2 is compressed by the additional compressor 124. As the density increases, the mass of the boil-off gas supplied to the second compressor 122 becomes larger even if the boil-off gas of the same flow rate is supplied to the second compressor 122. As a result, since the mass of the fluid used as the refrigerant in the second heat exchanger 140 after being compressed by the second compressor 122 becomes larger, the reliquefaction efficiency and reliquefaction amount in the second heat exchanger 140 are increased. Can be increased. When the additional compressor 124 is installed upstream of the second compressor 122, the present embodiment can be operated as a closed loop and an independent open loop, and the outlet pressure of the second compressor 122 can be controlled by the first compressor ( It may be operated in an open loop by adjusting the outlet pressure of 120).
또한, 추가압축기(124)가 제2 압축기(122) 하류에 설치되는 경우, 제2 압축기(122)의 용량에 의해 질량유량이 결정되고, 추가압축기(124)는 추가적인 압력을 높이는 역할만 하게 된다. 이 역시 기존 대비 효율 향상을 기대할 수는 있으나 제한적이므로, 추가압축기(124)는 제2 압축기(122) 상류에 설치되는 것이 바람직하다. 추가압축기(124)가 제2 압축기(122) 하류에 설치되는 경우, 본 실시예는 폐루프 및 독립 개루프로 운용할 수 있고, 제1 공급라인(L1)을 통과한 증발가스와 제2 공급라인(L2)를 통과한 증발가스의 압력이 서로 다르므로, 개루프로 운용하기는 어려울 수 있다.In addition, when the additional compressor 124 is installed downstream of the second compressor 122, the mass flow rate is determined by the capacity of the second compressor 122, the additional compressor 124 only serves to increase the additional pressure. . This also can be expected to improve efficiency compared to the existing, but is limited, it is preferable that the additional compressor 124 is installed upstream of the second compressor (122). When the additional compressor 124 is installed downstream of the second compressor 122, the present embodiment may operate as a closed loop and an independent open loop, and the second supply gas and the second supply gas passed through the first supply line L1. Since the pressure of the boil-off gas passing through the line (L2) is different from each other, it may be difficult to operate in an open loop.
본 실시예에서 추가압축기(124)를 설치하는 대신, 제2 압축기(122)의 압력과 용량을 높여도 유사한 효과를 달성할 수 있다. 그러나, 압력과 용량이 더 큰 제2 압축기(122)를 사용하면 비용이 증가하게 된다는 단점이 있다.Instead of installing the additional compressor 124 in this embodiment, a similar effect can be achieved by increasing the pressure and capacity of the second compressor 122. However, there is a disadvantage in that the cost is increased by using the second compressor 122 having a larger pressure and capacity.
본 실시예에 의하면, 냉매감압장치(160)가 생산하는 동력을 활용할 수 있고, 추가압축기(124)를 추가함으로써 적은 비용으로 재액화 효율 및 재액화량을 높일 수 있다. According to this embodiment, the power generated by the refrigerant pressure reducing device 160 can be utilized, and by adding an additional compressor 124, the reliquefaction efficiency and the amount of reliquefaction can be increased at a low cost.
본 실시예의 추가냉각기(134)는, 추가압축기(124)에 의해 압축되며 압력뿐만 아니라 온도도 높아진 증발가스의 온도를 낮춘다. 추가압축기(124)가 제2 압축기(122) 상류에 설치되는 경우에는, 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132) 순으로 설치되고, 추가압축기(124)가 제2 압축기(122) 하류에 설치되는 경우에는, 제2 압축기(122), 제2 냉각기(132), 추가압축기(124), 추가냉각기(134) 순으로 설치된다.The additional cooler 134 of the present embodiment lowers the temperature of the boil-off gas compressed by the additional compressor 124 and whose temperature as well as the pressure is increased. When the additional compressor 124 is installed upstream of the second compressor 122, the additional compressor 124, the additional cooler 134, the second compressor 122, and the second cooler 132 are installed in this order. When the compressor 124 is installed downstream of the second compressor 122, the second compressor 122, the second cooler 132, the additional compressor 124, and the additional cooler 134 are installed in this order.
본 실시예의 추진압축기(126)는, 제1 공급라인(L1)을 따라 연료수요처(180)로 공급되는 증발가스의 일부를 분기시켜 제1 열교환기(110)로 보내는, 복귀라인(L3) 상에 설치되어, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되는 증발가스의 압력을 높인다. 추진압축기(126)는, 증발가스를 임계점(메탄의 경우, 대략 55 bar) 이하의 압력까지 압축시킬 수도 있고, 임계점을 초과하는 압력까지 압축시킬 수도 있으며, 본 실시예의 추진압축기(126)가 증발가스를 임계점 이상까지 압축시키는 경우, 대략 300 bar로 압축시킬 수 있다.The propulsion compressor 126 according to the present embodiment diverges a portion of the boil-off gas supplied to the fuel demand 180 along the first supply line L1 and sends it to the first heat exchanger 110 on the return line L3. Is installed in, to increase the pressure of the boil-off gas supplied to the first heat exchanger 110 along the return line (L3). The propulsion compressor 126 may compress the boil-off gas to a pressure below the critical point (approximately 55 bar in the case of methane), or may compress it to a pressure above the critical point, the propulsion compressor 126 of the present embodiment evaporates If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.
본 실시예의 추진냉각기(136)는, 추진압축기(126) 하류의 복귀라인(L3) 상에 설치되어, 추진압축기(126)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스의 온도를 낮춘다.The propulsion cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126 to lower the temperature of the boil-off gas that has passed through the propulsion compressor 126 and has risen in temperature as well as pressure.
본 실시예의 선박은, 추진압축기(126)를 더 포함하여, 재액화 과정을 거치는 증발가스의 압력을 높일 수 있으므로, 재액화량 및 재액화 효율을 높일 수 있다.The ship of this embodiment may further include a propulsion compressor 126 to increase the pressure of the boil-off gas undergoing the reliquefaction process, thereby increasing the amount of reliquefaction and reliquefaction efficiency.
도 9는 서로 다른 압력하에서 열류량에 따른 메탄의 온도 값을 각각 나타낸 그래프이다. 도 9를 참조하면, 재액화 과정을 거치는 증발가스의 압력이 높을수록, 자가열교환의 효율이 높아짐을 확인할 수 있다. 자가열교환의 자가(Self-)는 저온의 증발가스 자체를 냉각 유체로 이용하여 고온의 증발가스와 열교환 시킨다는 의미를 가진다.9 is a graph showing the temperature values of methane according to the amount of heat flow under different pressures. 9, it can be seen that the higher the pressure of the boil-off gas undergoing the reliquefaction process, the higher the efficiency of self-heat exchange. Self- of self-heat exchange means that the low-temperature evaporation gas itself is used as a cooling fluid to exchange heat with the high-temperature evaporation gas.
도 9의 (a)는, 추진압축기(126) 및 추진냉각기(136)를 포함하지 않은 경우에 제2 열교환기(140)에서의 각 유체의 상태를 나타낸 것이고, 도 9의 (b)는 추진압축기(126) 및 추진냉각기(136)를 포함하는 경우에 제2 열교환기(140)에서의 각 유체의 상태를 나타낸 것이다.FIG. 9A shows the state of each fluid in the second heat exchanger 140 when the propulsion compressor 126 and the propulsion cooler 136 are not included, and FIG. 9B shows the propulsion. In the case of including the compressor 126 and the propulsion cooler 136 shows the state of each fluid in the second heat exchanger (140).
도 9의 (a) 및 (b)의 가장 위쪽의 그래프 I는, 재순환라인(L5)을 따라 제2 열교환기(140)로 공급되는 도 5의 A지점의 유체 상태를 나타낸 것이고, 가장 아래쪽의 그래프 L은, 재순환라인(L5)을 따라 제2 열교환기(140) 및 냉매감압장치(160)를 통과한 후 냉매로 사용되기 위하여 제2 열교환기(140)로 다시 공급되는 도 5의 C지점의 유체 상태를 나타낸 것이며, 중간 부분의 그래프 K와 겹쳐져서 그려진 그래프 J는, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급되는 도 5의 E지점의 유체 상태를 나타낸 것이다.The uppermost graph I of FIGS. 9A and 9B shows the fluid state at the point A of FIG. 5 supplied to the second heat exchanger 140 along the recirculation line L5, Graph L is point C of FIG. 5 which is fed back to second heat exchanger 140 for use as a refrigerant after passing through second heat exchanger 140 and refrigerant pressure reducing device 160 along recirculation line L5. 5 is a graph illustrating a fluid state of FIG. 5, which is overlapped with a graph K of the middle portion, and is supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110. The fluid state at point E is shown.
냉매로 사용되는 유체는, 열교환 과정에서 냉열을 빼앗겨 점점 온도가 증가하므로, 그래프 L은 시간의 흐름에 따라 왼쪽으로부터 오른쪽으로 진행되고, 냉매와 열교환되어 냉각되는 유체는, 열교환 과정에서 냉매로부터 냉열을 공급받아 점점 온도가 낮아지므로, 그래프 I 및 그래프 J는 시간의 흐름에 따라 오른쪽부터 왼쪽으로 진행된다.Since the fluid used as the refrigerant loses heat from the heat exchange process and gradually increases in temperature, the graph L proceeds from left to right with time, and the fluid heat-exchanged with the refrigerant cools the heat from the refrigerant during the heat exchange process. As the temperature is getting lower and lower, the graphs I and J progress from right to left over time.
도 9의 (a) 및 (b)의 중간 부분의 그래프 K는, 그래프 I와 그래프 J를 결합하여 나타낸 것이다. 즉, 제2 열교환기(140)에서 냉매로 사용되는 유체는 그래프 L로 그려지고, 제2 열교환기(140)에서 냉매와 열교환되어 냉각되는 유체는 그래프 K로 그려진다.The graph K of the middle part of FIG.9 (a) and (b) shows the graph I and the graph J combining. That is, the fluid used as the refrigerant in the second heat exchanger 140 is drawn by the graph L, and the fluid that is cooled by heat exchange with the refrigerant in the second heat exchanger 140 is drawn by the graph K.
열교환기를 설계할 때에는, 열교환기로 공급되는(즉, 도 5의 A지점, C지점, 및 E지점) 유체의 온도 및 열류량은 고정시키고, 냉매로 사용되는 유체의 온도가 냉각되는 유체의 온도보다 높아지지 않도록(즉, 그래프 L과 그래프 K가 교차되어 그래프 L이 그래프 K보다 위쪽에 나타나지 않도록) 하면서, 대수평균온도차(LMTD; Logarithmic Mean Temperature Difference)가 최대한 작아질 수 있도록 한다.When designing a heat exchanger, the temperature and heat flow of the fluid supplied to the heat exchanger (i.e., point A, point C and point E in FIG. 5) are fixed, and the temperature of the fluid used as the refrigerant is higher than the temperature of the fluid to be cooled. Ensure that the Logarithmic Mean Temperature Difference (LMTD) is as small as possible while avoiding (ie, intersecting graph L and graph K so that graph L does not appear above graph K).
대수평균온도차(LMTD)는, 고온 유체와 저온 유체가 서로 반대 방향에서 주입되고 반대쪽에서 배출되는 열교환 방식인 대향류의 경우, 저온 유체가 열교환기를 통과하기 전의 온도를 tc1, 저온 유체가 열교환기를 통과한 후의 온도를 tc2, 고온 유체가 열교환기를 통과하기 전의 온도를 th1, 고온 유체가 열교환기를 통과한 후의 온도를 th2라고 하고, d1= th2-tc1, d2=th1-tc2라고 하였을 때, (d2-d1)/ln(d2/d1)으로 표현되는 값인데, 대수평균온도차가 작을수록 열교환기의 효율은 높아진다.Logical mean temperature difference (LMTD) is a heat exchange method in which the hot fluid and the low temperature fluid are injected in opposite directions and discharged from the opposite direction. When the temperature after tc2 and the high temperature fluid pass through the heat exchanger is th1, and the temperature after the high temperature fluid passes through the heat exchanger is th2, and d1 = th2-tc1 and d2 = th1-tc2, (d2- d1) / ln (d2 / d1), the smaller the logarithmic mean temperature difference, the higher the efficiency of the heat exchanger.
그래프 상에서 대수평균온도차(LMTD)는, 냉매로 사용되는 저온 유체(도 9의 그래프 L)와 냉매와 열교환되어 냉각되는 고온 유체(도 9의 그래프 K)의 간격으로 나타내어 지는데, 도 9의 (a)보다 도 9의 (b)가 그래프 L과 그래프 K의 간격이 더 좁게 나타남을 알 수 있다.In the graph, the logarithmic mean temperature difference LMTD is represented by the interval between the low temperature fluid (graph L of FIG. 9) used as the refrigerant and the high temperature fluid (graph K of FIG. 9) cooled by heat exchange with the refrigerant. (B) of FIG. 9 shows that the interval between the graph L and the graph K is narrower.
이러한 차이는, 둥근 원으로 표시한 지점인 그래프 J의 초기값, 즉, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급되는 도 5의 E지점의 유체의 압력이, 도 9의 (a)보다 도 9의 (b)가 더 높기 때문에 나타난다.This difference is the initial value of the graph J, the point indicated by the round circle, that is, after passing through the first heat exchanger 110 is supplied to the second heat exchanger 140 along the return line (L3) of FIG. The pressure of the fluid at the point E is shown because FIG. 9 (b) is higher than that of FIG.
즉, 시뮬레이션 결과, 추진압축기(126)를 포함하지 않는 도 9의 (a)의 경우에는, 도 5의 E지점에서의 유체는 대략 -111℃, 20bar일 수 있고, 추진압축기(126)를 포함하는 도 9의 (b)의 경우에는, 도 5의 E지점에서의 유체는 대략 -90℃, 50bar일 수 있는데, 이러한 초기 조건 하에서 대수평균온도차(LMTD)가 가장 작아질 수 있도록 열교환기를 설계하면, 재액화 과정을 거치는 증발가스의 압력이 높은 도 9의 (b)의 경우에 열교환기의 효율이 더 높아지고, 결국 시스템 전반의 재액화량 및 재액화 효율이 높아지게 된다.That is, as a result of the simulation, in the case of FIG. 9A without the propulsion compressor 126, the fluid at the point E of FIG. 5 may be approximately −111 ° C., 20 bar, and includes the propulsion compressor 126. In the case of FIG. 9 (b), the fluid at point E of FIG. 5 may be approximately −90 ° C. and 50 bar. If the heat exchanger is designed so that the logarithmic mean temperature difference (LMTD) is the smallest under these initial conditions, In the case of (b) of FIG. 9, where the pressure of the boil-off gas undergoing the reliquefaction process is high, the efficiency of the heat exchanger is higher, and the amount of reliquefaction and reliquefaction efficiency of the overall system is increased.
도 9의 (a)의 경우에는, 제2 열교환기(140)에서 냉매로 사용되는 증발가스의 유량이 대략 6401 kg/h일 때, 냉매로 사용되는 유체(그래프 L)로부터 냉매와 열교환되어 냉각되는 유체(그래프 K)로 전달되는 총 열류량은 대략 585.4 kW이며, 재액화된 증발가스의 유량은 대략 3441 kg/h이다.In the case of FIG. 9A, when the flow rate of the boil-off gas used as the refrigerant in the second heat exchanger 140 is approximately 6401 kg / h, the refrigerant is exchanged with the refrigerant from the fluid (graph L) used as the refrigerant and cooled. The total heat flow delivered to the fluid (graph K) is approximately 585.4 kW and the flow rate of the reliquefied boil-off gas is approximately 3441 kg / h.
도 9의 (b)의 경우에는, 제2 열교환기(140)에서 냉매로 사용되는 증발가스의 유량이 대략 5368 kg/h일 때, 냉매로 사용되는 유체(그래프 L)로부터 냉매와 열교환되어 냉각되는 유체(그래프 K)로 전달되는 총 열류량은 대략 545.2 kW이며, 재액화된 증발가스의 유량은 대략 4325 kg/h이다.In the case of FIG. 9B, when the flow rate of the boil-off gas used as the refrigerant in the second heat exchanger 140 is approximately 5368 kg / h, the refrigerant is exchanged with the refrigerant from the fluid (graph L) used as the refrigerant and cooled. The total heat flow delivered to the fluid (graph K) is approximately 545.2 kW, and the flow rate of the reliquefied boil-off gas is approximately 4325 kg / h.
즉, 추진압축기(126)를 포함하여 재액화 과정을 거치는 증발가스의 압력을 높이면 더 적은 냉매를 사용해도 더 많은 양의 증발가스를 재액화시킬 수 있음을 알 수 있다.That is, it can be seen that by increasing the pressure of the boil-off gas including the propulsion compressor 126 to undergo the re-liquefaction process, it is possible to re-liquefy a larger amount of boil-off gas even with less refrigerant.
이와 같이, 본 실시예의 선박은, 추진압축기(126)를 포함하므로 재액화량 및 재액화 효율을 높일 수 있고, 재액화량 및 재액화 효율을 높여 제2 압축기(122)를 구동시키지 않아도 증발가스를 모두 처리할 수 있는 경우가 증가하므로, 제2 압축기(122)의 사용 빈도를 줄일 수 있다는 장점이 있다.As described above, since the ship of the present embodiment includes the propulsion compressor 126, the reliquefaction amount and the reliquefaction efficiency can be increased, and the reliquefaction amount and the reliquefaction efficiency are increased to drive the second compressor 122 without the need to drive the second compressor 122. Since both cases can be increased, there is an advantage that the frequency of use of the second compressor 122 can be reduced.
제2 압축기(122)를 이용하여 재액화 효율을 높일 수는 있지만, 제2 압축기(122)를 구동시키는 시간이 길수록, 제1 압축기(120)가 고장난 경우를 대비한다는 리던던시(Redundancy)의 개념은 약해지게 된다. 본 실시예의 선박은, 추진압축기(126)를 포함하여 제2 압축기(122)의 사용 빈도를 줄일 수 있으므로, 리던던시의 개념을 충분히 확보할 수 있다.Although the re-liquefaction efficiency can be increased by using the second compressor 122, the concept of redundancy that the longer the time for driving the second compressor 122 is to prepare for the failure of the first compressor 120 is It will weaken. Since the ship of this embodiment can reduce the frequency of use of the second compressor 122, including the propulsion compressor 126, the concept of redundancy can be sufficiently secured.
또한, 추진압축기(126)는, 일반적으로 제1 압축기(120) 또는 제2 압축기(122)의 대략 1/2 용량을 가지는 것으로 충분하므로, 제2 압축기(122)를 구동시키지 않고 추진압축기(126)와 제1 압축기(120)만을 구동시켜 시스템을 운용하는 경우, 추진압축기(126)를 설치하지 않는 경우에 비해, 운용 비용을 절약할 수 있다.In addition, since the propulsion compressor 126 is generally sufficient to have approximately 1/2 the capacity of the first compressor 120 or the second compressor 122, the propulsion compressor 126 is driven without driving the second compressor 122. In the case of operating the system by driving only the first compressor 120 and), it is possible to save the operating cost than when the propulsion compressor 126 is not installed.
다시 도 5를 참조하면, 본 실시예의 제1 추가라인(L6)의 일측은, 냉매감압장치(160)에 의해 팽창된 후 제2 열교환기(140)를 통과한 증발가스를 제1 공급라인(L1)으로 보내는, 재순환라인(L5) 상에 연결되고, 타측은, 제3 밸브(193)와 제2 압축기(122) 사이의 제2 공급라인(L2) 상에 연결된다.Referring to FIG. 5 again, one side of the first additional line L6 according to the present embodiment may expand the evaporated gas passing through the second heat exchanger 140 after being expanded by the refrigerant pressure reducing device 160 to the first supply line. Connected to a recirculation line L5, which is sent to L1, the other side is connected to a second supply line L2 between the third valve 193 and the second compressor 122.
본 실시예의 제9 밸브(201)는, 재순환라인(L5)이 제1 압축기(120) 및 제2 압축기(122) 상류의 제1 공급라인(L1)과 만나는 지점과, 재순환라인(L5)이 제1 추가라인(L6)과 만나는 지점 사이의, 재순환라인(L5) 상에 설치된다. 또한, 본 실시예의 선박은, 제3 실시예와는 달리, 제2 압축기(122) 하류 쪽 제2 공급라인(L2)이 제1 공급라인(L1)이 아닌 재순환라인(L5)과 연결된다.The ninth valve 201 of the present embodiment has a point where the recirculation line L5 meets the first supply line L1 upstream of the first compressor 120 and the second compressor 122, and the recirculation line L5 is Between the point where it meets the 1st additional line L6, it is installed on the recycle line L5. In addition, unlike the third embodiment, the ship of the present embodiment, the second supply line (L2) downstream of the second compressor 122 is connected to the recirculation line (L5), not the first supply line (L1).
본 실시예의 제12 밸브(205)는, 제2 공급라인(L2)과 제2 열교환기(140) 사이의 재순환라인(L5) 상에 설치되어, 유체의 유량 및 개폐를 조절한다.The twelfth valve 205 of the present embodiment is installed on the recirculation line L5 between the second supply line L2 and the second heat exchanger 140 to regulate the flow rate and opening and closing of the fluid.
본 실시예의 제1 내지 제12 밸브(191, 192, 193, 194, 195, 196, 197, 198, 201, 202, 203, 205)는, 시스템 운용 상황을 사람이 직접 판단하여 수동으로 조절될 수도 있고, 미리 설정된 값에 의해 개폐되도록 자동으로 조절될 수도 있다.The first to twelfth valves 191, 192, 193, 194, 195, 196, 197, 198, 201, 202, 203, and 205 of the present embodiment may be manually adjusted by a person directly determining a system operating situation. It may be automatically adjusted to open and close by a preset value.
본 실시예의 선박의 제3 실시예와 차별되는 특징은, 냉매 사이클을 개루프뿐만 아니라 폐루프로도 운용할 수 있도록 하여, 선박의 운항 조건에 따라 재액화 시스템을 더 유연하게 사용하기 위함이며, 이하, 추가압축기(124)가 제2 압축기(122) 상류에 설치된 경우, 밸브 조절을 통해 냉매 사이클을 폐루프로 운용하는 방법 및 개루프로 운용하는 방법을 설명한다.A feature that is different from the third embodiment of the ship of this embodiment is that the refrigerant cycle can be operated not only in the open loop but also in the closed loop, so that the reliquefaction system can be used more flexibly according to the operating conditions of the ship. Hereinafter, when the additional compressor 124 is installed upstream of the second compressor 122, a method of operating a refrigerant cycle in a closed loop and a method of operating in an open loop through valve adjustment will be described.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하기 위해서, 일단, 제1 밸브(191), 제2 밸브(192), 제3 밸브(193), 제4 밸브(194), 제10 밸브(202), 및 제12 밸브(205)는 열고, 제6 밸브(196) 및 제9 밸브(201)는 닫은 상태에서 시스템을 구동시킨다.In order to operate the refrigerant cycle of the ship of this embodiment as a closed loop, once, the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the tenth valve 202 And the twelfth valve 205 open, and the sixth valve 196 and the ninth valve 201 drive the system in the closed state.
저장탱크(T)로부터 배출된 후 제2 압축기(122)에 의해 압축된 증발가스가 재순환라인(L5)으로 공급되면, 제3 밸브(193)를 닫아, 증발가스가 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194), 제12 밸브(205), 제2 열교환기(140), 냉매감압장치(160), 다시 제2 열교환기(140), 및 제10 밸브(202)를 순환하는, 폐루프의 냉매 사이클을 형성시킨다.When the boil-off gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recirculation line L5, the third valve 193 is closed to add the boil-off gas to the additional compressor 124. Cooler 134, second compressor 122, second cooler 132, fourth valve 194, twelfth valve 205, second heat exchanger 140, refrigerant pressure reducing device 160, and A closed loop refrigerant cycle is formed to circulate the second heat exchanger 140 and the tenth valve 202.
냉매 사이클을 폐루프로 구성하는 경우에는, 질소가스를 폐루프를 순환하는 냉매로 사용할 수도 있다. 이 경우, 본 실시예의 저장탱크를 포함하는 저장탱크는, 질소가스를 폐루프의 냉매 사이클 내로 도입시키는 배관을 더 포함할 수 있다.When the refrigerant cycle is configured as a closed loop, nitrogen gas may be used as the refrigerant circulating in the closed loop. In this case, the storage tank including the storage tank of the present embodiment may further include a pipe for introducing nitrogen gas into the refrigerant cycle of the closed loop.
냉매 사이클이 폐루프로 운용되는 경우, 폐루프를 순환하는 증발가스만이 제2 열교환기(140)에서의 냉매로 사용되며, 제1 압축기(120)를 통과한 증발가스는 냉매 사이클로 도입되지 못하고 연료수요처(180)로 공급되거나, 복귀라인(L3)을 따라 재액화 과정을 거치게 된다. 따라서, 재액화량이나, 연료수요처(180)에서 요구하는 증발가스량에 무관하게 일정한 유량의 증발가스가 제2 열교환기(140)의 냉매로 순환된다.When the refrigerant cycle is operated as a closed loop, only the boil-off gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the boil-off gas passing through the first compressor 120 cannot be introduced into the refrigerant cycle. It is supplied to the fuel demand 180, or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction or the amount of boil-off gas required by the fuel demand unit 180, the boil-off gas of a constant flow rate is circulated to the refrigerant of the second heat exchanger 140.
본 실시예의 냉매 사이클이 폐루프로 운용되는 경우, 개루프 또는 독립 개루프로 운용되는 경우에 비해, 재액화 과정을 거치는 증발가스와 냉매로 사용되는 증발가스 각각의 유량을 제어하기가 용이하다는 장점이 있다.When the refrigerant cycle of the present embodiment is operated in a closed loop, it is easier to control the flow rate of each of the evaporated gas that is undergoing the reliquefaction process and the evaporated gas used as the refrigerant compared to the case of operating the closed loop or the independent open loop. There is this.
또한, 본 실시예의 제1 공급라인(L1)에는 한 대의 압축기(120)만 설치되고, 제2 공급라인(L2)에는 두 대의 압축기(122, 124)가 설치되므로, 제1 공급라인(L1)을 통과한 증발가스와 제2 공급라인(L2)을 통과한 증발가스의 압력이 서로 다를 수 있다. 제1 공급라인(L1)을 통과한 증발가스와 제2 공급라인(L2)을 통과한 증발가스의 압력이 서로 다른 경우에는, 본 실시예의 냉매 사이클은 폐루프 또는 독립 폐루프로 운용되는 것이 바람직하다.In addition, since only one compressor 120 is installed in the first supply line L1 of the present embodiment, and two compressors 122 and 124 are installed in the second supply line L2, the first supply line L1. The pressure of the boil-off gas passing through and the boil-off gas passing through the second supply line L2 may be different. When the pressures of the boil-off gas passing through the first supply line L1 and the boil-off gas passing through the second supply line L2 are different from each other, the refrigerant cycle of the present embodiment is preferably operated as a closed loop or an independent closed loop. Do.
본 실시예의 선박의 냉매 사이클이 폐루프로 운용되는 경우의 증발가스의 흐름을 설명하면 다음과 같다.Referring to the flow of the boil-off gas when the refrigerant cycle of the ship of the present embodiment is operated in a closed loop as follows.
저장탱크(T)로부터 배출된 증발가스는 제1 열교환기(110)를 통과한 후 제1 압축기(120)에 의해 압축되고 제1 냉각기(130)에 의해 냉각된 후 일부는 연료수요처(180)로 보내지고, 나머지 일부는 복귀라인(L3)을 따라 재액화 과정을 거치게 된다.The boil-off gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, and a part of the fuel demand unit 180 is removed. The remaining part is subjected to the reliquefaction process along the return line (L3).
복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스는, 추진압축기(126)에 의해 압축되고 추진냉각기(136)에 의해 냉각된 후, 제1 열교환기(110)에 의해 저장탱크(T)로부터 배출된 증발가스와 열교환되어 냉각된다. 제1 열교환기(110)에 의해 냉각된 증발가스는, 제2 열교환기(140)에서 열교환되어 추가적으로 냉각된 후 제1 감압장치(150)에 의해 팽창되어 일부 또는 전부가 재액화된다.The boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled. The boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
본 실시예에서는 복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스가, 추진압축기(126)에 의해 압축된 후 제1 열교환기(110) 및 제2 열교환기(140)에서 두 번에 걸쳐 냉각되는 경우를 설명하였으나, 추진압축기(126)에 의해 압축된 증발가스는 바로 제2 열교환기(140)로 보내져 냉각된 후 제1 감압장치(150)에 의해 팽창되어 재액화될 수도 있다. 본 실시예의 냉매 사이클이 개루프 및 독립 개루프로 운용되는 경우도 동일하다.In the present embodiment, the boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and then twice in the first heat exchanger 110 and the second heat exchanger 140. Although the case of cooling has been described, the boil-off gas compressed by the propulsion compressor 126 may be directly sent to the second heat exchanger 140 to be cooled, and then expanded and re-liquefied by the first pressure reducing device 150. The same applies to the case where the refrigerant cycle of this embodiment is operated in an open loop and an independent open loop.
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는, 일부 또는 전부 재액화된 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는, 일부 또는 전부 재액화된 증발가스는 기액분리기(170)로 보내진다. 기액분리기(170)에 의해 분리된 기체는, 저장탱크(T)로부터 배출되는 증발가스와 합류되어 제1 열교환기(110)로 보내지고, 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 보내진다.When the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
한편, 냉매 사이클을 순환하는 증발가스는, 추가압축기(124)에 의해 압축되고 추가냉각기(134)에 의해 냉각된 후, 제2 압축기(122)에 의해 추가적으로 압축되고 제2 냉각기(132)에 의해 냉각되어, 재순환라인(L5)을 따라 제2 열교환기(140)로 보내진다. 추가압축기(124) 및 제2 압축기(122)를 통과한 후 제2 열교환기(140)로 보내진 증발가스는, 제2 열교환기(140)에서 1차로 열교환되어 냉각된 후 냉매감압장치(160)로 보내져 2차로 팽창되어 냉각된다.On the other hand, the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the second compressor 122 and by the second cooler 132. Cooled and sent to the second heat exchanger 140 along the recycle line (L5). After passing through the additional compressor 124 and the second compressor 122, the boil-off gas sent to the second heat exchanger 140 is first heat-exchanged by the second heat exchanger 140, and then cooled. It is sent to the secondary expansion and cooled.
본 실시예에서는 재순환라인(L5)을 따라 냉매로 사용되는 증발가스가, 제2 열교환기(140)를 1차로 통과한 후 냉매감압장치(160)를 거쳐 제2 열교환기(140)로 다시 보내지는 경우를 설명하였으나, 재순환라인(L5)을 따라 냉매로 사용되는 증발가스는, 제2 열교환기(140)를 거치지 않고 바로 냉매감압장치(160)로 보내진 후, 제2 열교환기(140)로 보내질 수 있다. 본 실시예의 냉매 사이클이 개루프 및 독립 개루프로 운용되는 경우도 동일하다.In this embodiment, the boil-off gas used as the refrigerant along the recirculation line L5 passes first through the second heat exchanger 140 and then is sent back to the second heat exchanger 140 through the refrigerant pressure reducing device 160. Although the case has been described, the evaporated gas used as the refrigerant along the recirculation line (L5) is sent directly to the refrigerant decompression device 160 without passing through the second heat exchanger 140, and then to the second heat exchanger 140. Can be sent. The same applies to the case where the refrigerant cycle of this embodiment is operated in an open loop and an independent open loop.
냉매감압장치(160)를 통과한 증발가스는 다시 제2 열교환기(140)로 보내져, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급된 증발가스; 및 추가압축기(124)와 제2 압축기(122)에 의해 압축된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 공급된 증발가스;를 냉각시키는 냉매로 사용된다. 냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 냉매로 사용된 증발가스는, 다시 추가압축기(124)로 보내져 상술한 일련의 과정을 반복한다.The evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
본 실시예의 선박의 냉매 사이클이 폐루프로 운용되는 도중, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나게 되면, 제1 밸브(191), 제2 밸브(192), 제10 밸브(202), 및 제12 밸브(205)는 닫고, 제3 밸브(193) 및 제6 밸브(196)는 열어, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스가, 제3 밸브(193), 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194) 및 제6 밸브(196)를 거쳐 연료수요처(180)로 공급되도록 한다. 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스를, 제2 열교환기(140)의 냉매로 사용할 필요가 있는 경우에는, 제9 밸브(201) 및 제12 밸브(205)를 열고 시스템을 운용할 수도 있다.If the first compressor 120 or the first cooler 130 fails while the refrigerant cycle of the ship of the present embodiment is operated in a closed loop, the first valve 191, the second valve 192, and the tenth valve 202 and the twelfth valve 205 are closed, the third valve 193 and the sixth valve 196 are opened, the evaporation passed through the first heat exchanger 110 after being discharged from the storage tank (T). The gas is connected to the third valve 193, the additional compressor 124, the additional cooler 134, the second compressor 122, the second cooler 132, the fourth valve 194 and the sixth valve 196. To be supplied to the fuel demand unit 180. When it is necessary to use the evaporated gas compressed by the additional compressor 124 and the second compressor 122 as the refrigerant of the second heat exchanger 140, the ninth valve 201 and the twelfth valve 205 are used. You can also open and operate the system.
본 실시예의 선박의 냉매 사이클을 개루프로 운용하기 위해서, 제1 밸브(191), 제2 밸브(192), 제3 밸브(193), 제4 밸브(194), 제6 밸브(196), 제9 밸브(201), 및 제12 밸브(205)는 열고, 제10 밸브(202)는 닫는다.In order to operate the refrigerant cycle of the ship of the present embodiment in an open loop, the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the sixth valve 196, The ninth valve 201 and the twelfth valve 205 are opened, and the tenth valve 202 is closed.
냉매 사이클을 폐루프로 운용하면, 냉매 사이클을 순환하는 증발가스와, 연료수요처(180)로 보내지거나 복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스가 분리된다. 반면, 냉매 사이클을 개루프로 운용하면, 제1 압축기(120)에 의해 압축된 증발가스와 제2 압축기(122)에 의해 압축된 증발가스가 합류되어, 제2 열교환기(140)에서 냉매로 사용되거나, 연료수요처(180)로 보내지거나, 복귀라인(L3)을 따라 재액화 과정을 거치게 된다.When the refrigerant cycle is operated as a closed loop, the boil-off gas circulating through the refrigerant cycle and the boil-off gas sent to the fuel demand 180 or undergoing reliquefaction along the return line L3 are separated. On the other hand, when the refrigerant cycle is operated as an open loop, the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the second compressor 122 are joined together, and the refrigerant is transferred from the second heat exchanger 140 to the refrigerant. It may be used, or may be sent to the fuel demand 180, or undergo a reliquefaction process along the return line (L3).
따라서, 냉매 사이클을 개루프로 운용하면, 재액화량 및 연료수요처(180)에서의 증발가스 요구량을 고려하여, 제2 열교환기(140)로 보내는 냉매의 유량을 유동적으로 조절할 수 있다. 특히, 연료수요처(180)에서의 증발가스 요구량이 적은 경우, 제2 열교환기(140)로 보내는 냉매의 유량을 증가시키면 재액화 효율 및 재액화량을 높일 수 있다.Therefore, when the refrigerant cycle is operated in an open loop, the flow rate of the refrigerant to be sent to the second heat exchanger 140 may be flexibly adjusted in consideration of the amount of reliquefaction and the amount of boil-off gas required by the fuel demand 180. In particular, when the amount of boil-off gas in the fuel demand unit 180 is small, increasing the flow rate of the refrigerant sent to the second heat exchanger 140 may increase the reliquefaction efficiency and the amount of reliquefaction.
본 실시예의 선박의 냉매 사이클이 개루프로 운용되는 경우의 증발가스의 흐름을 설명하면 다음과 같다.Referring to the flow of the boil-off gas when the refrigerant cycle of the ship of the present embodiment is operated in an open loop as follows.
저장탱크(T)로부터 배출된 증발가스는, 제1 열교환기(110)를 통과한 후 두 흐름으로 분기하여 일부는 제1 공급라인(L1)으로 보내지고 나머지 일부는 제2 공급라인(L2)으로 보내진다.The boil-off gas discharged from the storage tank T passes through the first heat exchanger 110 and then branches into two streams, partly to the first supply line L1, and the other part to the second supply line L2. Is sent to.
제1 공급라인(L1)으로 보내진 증발가스는, 제1 밸브(191), 제1 압축기(120), 제1 냉각기(130) 및 제2 밸브(192) 통과한 후, 일부는 제6 밸브(196) 및 제12 밸브(205)를 지나 제2 열교환기(140)로 보내지고, 다른 일부는 다시 두 흐름으로 분기한다. 두 흐름으로 분기한 증발가스 중 한 흐름은 연료수요처(180)로 보내지고, 나머지는 복귀라인(L3)을 따라 추진압축기(126)로 보내진다.The boil-off gas sent to the first supply line L1 passes through the first valve 191, the first compressor 120, the first cooler 130, and the second valve 192, and a part thereof includes a sixth valve ( 196 and twelfth valve 205 are sent to second heat exchanger 140, the other part again diverging in two flows. One stream of the boil-off gas branched into two streams is sent to the fuel demand unit 180, and the other is sent to the propulsion compressor 126 along the return line (L3).
제2 공급라인(L2)으로 보내진 증발가스는, 제3 밸브(193), 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132) 및 제4 밸브(194)를 통과한 후, 일부는 제12 밸브(205)를 지나 제2 열교환기(140)로 보내지고, 다른 일부는 제1 공급라인(L1)으로 보내진 후 두 흐름으로 분기한다. 두 흐름으로 분기한 증발가스 중 한 흐름은 연료수요처(180)로 보내지고, 나머지 흐름은 복귀라인(L3)을 따라 추진압축기(126)로 보내진다.The boil-off gas sent to the second supply line L2 includes a third valve 193, an additional compressor 124, an additional cooler 134, a second compressor 122, a second cooler 132, and a fourth valve ( After passing 194, a portion is passed through the twelfth valve 205 to the second heat exchanger 140, and another portion is sent to the first supply line L1 and branches into two flows. One stream of the boil-off gas branched into two streams is sent to the fuel demand unit 180, and the other stream is sent to the propulsion compressor 126 along the return line (L3).
설명의 편의를 위해, 제1 압축기(120)에 의해 압축된 증발가스와 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스를 분리하여 설명하였으나, 제1 압축기(120)에 의해 압축된 증발가스와 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스는, 각각 분리되어 흐르는 것이 아니라, 합류되어 제2 열교환기(140), 연료수요처(180) 또는 추진압축기(126)로 공급되는 것이다.For convenience of description, the evaporated gas compressed by the first compressor 120 and the evaporated gas compressed by the additional compressor 124 and the second compressor 122 are separated and described. The boil-off gas compressed by the boil-off gas and the boil-off gas compressed by the additional compressor 124 and the second compressor 122 are not separately flowed, but joined together to form the second heat exchanger 140, the fuel demand 180, or the propulsion. It is supplied to the compressor 126.
즉, 제2 열교환기(140)로 증발가스를 보내는 재순환라인(L5), 연료수요처(180)로 증발가스를 보내는 제1 공급라인(L1), 제1 열교환기(110)로 증발가스를 보내는 복귀라인(L3)에는, 제1 압축기(120)에 의해 압축된 증발가스와 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스가 혼합되어 흐른다.That is, the recirculation line (L5) for sending the boil-off gas to the second heat exchanger 140, the first supply line (L1) for sending the boil-off gas to the fuel demand (180), the boil-off gas to the first heat exchanger (110) In the return line L3, the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the additional compressor 124 and the second compressor 122 flow.
재순환라인(L5)을 따라 제2 열교환기(140)로 보내진 증발가스는, 제2 열교환기(140)에서 1차로 열교환되어 냉각되고, 냉매감압장치(160)에 의해 2차로 팽창되어 냉각된 후 다시 제2 열교환기(140)로 공급된다. 냉매감압장치(160)를 통과한 후 제2 열교환기(140)로 공급된 증발가스는, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급된 증발가스; 및 재순환라인(L5)을 따라 제2 열교환기(140)로 공급된, 제1 압축기(120)에 의해 압축된 증발가스와 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스가 합류된 흐름;과 열교환된다.The boil-off gas sent to the second heat exchanger 140 along the recirculation line L5 is first heat exchanged and cooled in the second heat exchanger 140, and is secondly expanded and cooled by the refrigerant pressure reducing device 160. Again supplied to the second heat exchanger (140). After passing through the refrigerant pressure reducing device 160, the boil-off gas supplied to the second heat exchanger 140 passes through the first heat exchanger 110 and then passes through the return line L3 to the second heat exchanger 140. Supplied boil-off gas; And the boil-off gas compressed by the first compressor 120 and the boil-off gas compressed by the additional compressor 124 and the second compressor 122, supplied to the second heat exchanger 140 along the recirculation line L5. Heat exchange with the joined flow.
냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 냉매로 사용된 증발가스는, 제9 밸브(201)를 지나 제1 공급라인(L1)으로 보내져, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 지난 증발가스와 합류되어, 상술한 일련의 과정을 반복한다.After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the first supply line L1 through the ninth valve 201, and is stored from the storage tank T. After the discharge, the first heat exchanger 110 is joined with the evaporated gas, and the above-described series of processes are repeated.
한편, 복귀라인(L3)을 따라 추진압축기(126)로 보내진 증발가스는, 추진압축기(124)에 의해 압축되고, 추진냉각기(134)에 의해 냉각된 후, 제1 열교환기(110)로 보내진다. 제1 열교환기(110)로 보내진 증발가스는, 제1 열교환기(110)에서 1차로 냉각되고, 제2 열교환기(140)에서 2차로 냉각된 후 제1 감압장치(150)에 의해 팽창되어 일부 또는 전부가 재액화된다.Meanwhile, the boil-off gas sent to the propulsion compressor 126 along the return line L3 is compressed by the propulsion compressor 124, cooled by the propulsion cooler 134, and then sent to the first heat exchanger 110. Lose. The boil-off gas sent to the first heat exchanger 110 is first cooled in the first heat exchanger 110, secondly cooled in the second heat exchanger 140, and then expanded by the first pressure reducing device 150. Some or all reliquefy
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는, 일부 또는 전부 재액화된 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는, 일부 또는 전부 재액화된 증발가스는 기액분리기(170)로 보내진다. 기액분리기(170)에 의해 분리된 기체는, 저장탱크(T)로부터 배출되는 증발가스와 합류되어 제1 열교환기(110)로 보내지고, 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 보내진다.When the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
본 실시예의 선박의 냉매 사이클이 개루프로 운용되는 도중, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나게 되면, 제1 밸브(191), 제2 밸브(192), 제9 밸브(201), 및 제12 밸브(205)를 닫아, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스가, 제3 밸브(193), 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194) 및 제6 밸브(196)를 거쳐 연료수요처(180)로 공급되도록 한다. 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스를, 제2 열교환기(140)의 냉매로 사용할 필요가 있는 경우에는, 제9 밸브(201) 및 제12 밸브(205)를 열고 시스템을 운용할 수도 있다.If the first compressor 120 or the first cooler 130 is broken while the refrigerant cycle of the ship of the present embodiment is operating in an open loop, the first valve 191, the second valve 192, and the ninth valve 201 and the 12th valve 205 are closed, and the boil-off gas which passed through the 1st heat exchanger 110 after discharge | emitted from the storage tank T, the 3rd valve 193, the additional compressor 124, The additional cooler 134, the second compressor 122, the second cooler 132, the fourth valve 194 and the sixth valve 196 may be supplied to the fuel demand 180. When it is necessary to use the evaporated gas compressed by the additional compressor 124 and the second compressor 122 as the refrigerant of the second heat exchanger 140, the ninth valve 201 and the twelfth valve 205 are used. You can also open and operate the system.
본 실시예의 선박은, 냉매 사이클을 개루프로 운용하면서도, 제2 압축기(122)에 의해 압축된 증발가스는 제2 열교환기(140)의 냉매로만 사용하고, 제1 압축기(120)에 의해 압축된 증발가스는, 연료수요처(180)로 보내거나 복귀라인(L3)을 따라 재액화 과정을 거치게 하고, 제2 열교환기(140)의 냉매로는 사용하지 않도록, 제2 압축기(122)와 제1 압축기(120)를 독립적으로 운용할 수도 있다. 이하, 제2 압축기(122)와 제1 압축기(120)를 독립적으로 운용하는 개루프의 냉매 사이클을 '독립 개루프'라고 한다.While the vessel of the present embodiment operates the refrigerant cycle in an open loop, the boil-off gas compressed by the second compressor 122 is used only as the refrigerant of the second heat exchanger 140 and is compressed by the first compressor 120. The evaporated gas is sent to the fuel demand unit 180 or undergoes a reliquefaction process along the return line L3, and the second compressor 122 and the second compressor 122 are not used as the refrigerant of the second heat exchanger 140. 1 compressor 120 may be operated independently. Hereinafter, the refrigerant cycle of the open loop for independently operating the second compressor 122 and the first compressor 120 is referred to as an 'independent open loop'.
본 실시예의 선박의 냉매 사이클을 독립 개루프로 운용하기 위해서, 제1 밸브(191), 제2 밸브(192), 제3 밸브(193), 제4 밸브(194), 제9 밸브(201) 및 제12 밸브(205)는 열고, 제6 밸브(196) 및 제10 밸브(202)는 닫는다. 냉매 사이클을 독립 개루프로 운용하면, 폐루프로 운용할 때에 비하여 비교적 유동적인 시스템의 운용이 가능하면서도, 개루프로 운용할 때에 비하여 시스템의 운전이 용이해 진다는 장점이 있다.In order to operate the refrigerant cycle of the ship of this embodiment as an independent open loop, the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the ninth valve 201. And the twelfth valve 205 is opened, and the sixth valve 196 and the tenth valve 202 are closed. When the refrigerant cycle is operated in an independent open loop, it is possible to operate a relatively flexible system compared to when operating in a closed loop, but it is easy to operate the system as compared to when operating in an open loop.
본 실시예의 선박의 냉매 사이클이 독립 개루프로 운용되는 경우의 증발가스의 흐름을 설명하면 다음과 같다.Referring to the flow of the boil-off gas when the refrigerant cycle of the ship of the present embodiment is operated in an independent open loop as follows.
저장탱크(T)로부터 배출된 증발가스는 제1 열교환기(110)를 통과한 후 두 흐름으로 분기하여 일부는 제1 공급라인(L1)으로 보내지고 나머지 일부는 제2 공급라인(L2)으로 보내진다. 제1 공급라인(L1)으로 보내진 증발가스는, 제1 밸브(191), 제1 압축기(120), 제1 냉각기(130) 및 제2 밸브(192)를 통과한 후 일부는 연료수요처(180)로 보내지고, 다른 일부는 복귀라인(L3)을 따라 추진압축기(126)로 보내진다.The boil-off gas discharged from the storage tank T passes through the first heat exchanger 110 and then branches into two streams, partly to the first supply line L1, and partly to the second supply line L2. Is sent. The boil-off gas sent to the first supply line L1 passes through the first valve 191, the first compressor 120, the first cooler 130, and the second valve 192, and a part of the fuel demand 180 ) And the other part to the propulsion compressor 126 along the return line (L3).
제2 공급라인(L2)으로 보내진 증발가스는, 제3 밸브(193), 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194) 및 제12 밸브(205)를 통과한 후 재순환라인(L5)을 따라 제2 열교환기(140)로 보내진다.The boil-off gas sent to the second supply line L2 may include a third valve 193, an additional compressor 124, an additional cooler 134, a second compressor 122, a second cooler 132, and a fourth valve ( After passing through the 194 and the twelfth valves 205, it is sent to the second heat exchanger 140 along the recirculation line L5.
추가압축기(124) 및 제2 압축기(122)에 의해 압축된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 보내진 증발가스는, 제2 열교환기(140)에서 1차로 열교환되어 냉각되고, 냉매감압장치(160)에 의해 2차로 팽창되어 냉각된 후 다시 제2 열교환기(140)로 공급되어, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 통해 제2 열교환기(140)로 공급된 증발가스; 및 추가압축기(124)와 제2 압축기(122)에 의해 압축된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 공급된 증발가스;를 냉각시키는 냉매로 사용된다.The boil-off gas, which is compressed by the additional compressor 124 and the second compressor 122, and then sent to the second heat exchanger 140 along the recirculation line L5, is first heat-exchanged by the second heat exchanger 140 and cooled. After the second expansion by the refrigerant pressure reducing device 160 is cooled and supplied again to the second heat exchanger 140, the second heat exchanger through the return line (L3) after passing through the first heat exchanger (110) Boil-off gas supplied to the unit 140; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5.
냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 냉매로 사용된 증발가스는, 제9 밸브(201)를 지나 제1 공급라인(L1)으로 보내져, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 지난 증발가스와 합류되어, 상술한 일련을 과정을 반복한다.After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the first supply line L1 through the ninth valve 201, and is stored from the storage tank T. After the discharge is joined with the boil-off gas passing through the first heat exchanger 110, the above-described process is repeated.
제1 압축기(120)에 의해 압축된 후 복귀라인(L3)을 따라 추진압축기(126)로 보내진 증발가스는, 추진압축기(124)에 의해 압축되고, 추진냉각기(134)에 의해 냉각된 후, 제1 열교환기(110)로 보내진다. 제1 열교환기(110)로 보내진 증발가스는, 제1 열교환기(110)에서 1차로 냉각되고, 제2 열교환기(140)에서 2차로 냉각된 후 제1 감압장치(150)에 의해 팽창되어 일부 또는 전부가 재액화된다.After being compressed by the first compressor 120, the evaporated gas sent to the propulsion compressor 126 along the return line L3 is compressed by the propulsion compressor 124 and cooled by the propulsion cooler 134. It is sent to the first heat exchanger (110). The boil-off gas sent to the first heat exchanger 110 is first cooled in the first heat exchanger 110, secondly cooled in the second heat exchanger 140, and then expanded by the first pressure reducing device 150. Some or all reliquefy
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는, 일부 또는 전부 재액화된 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는, 일부 또는 전부 재액화된 증발가스는 기액분리기(170)로 보내진다. 기액분리기(170)에 의해 분리된 기체는, 저장탱크(T)로부터 배출되는 증발가스와 합류되어 제1 열교환기(110)로 보내지고, 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 보내진다.When the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
본 실시예의 선박의 냉매 사이클이 독립 개루프로 운용되는 도중, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나게 되면, 제1 밸브(191), 제2 밸브(192), 제9 밸브(201) 및 제12 밸브(205)를 닫고, 제6 밸브(196)를 열어, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스가, 제3 밸브(193), 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194) 및 제6 밸브(196)를 거쳐 연료수요처(180)로 공급되도록 한다. 추가압축기(124) 및 제2 압축기(122)에 의해 압축된 증발가스를, 제2 열교환기(140)의 냉매로 사용할 필요가 있는 경우에는, 제9 밸브(201) 및 제12 밸브(205)를 열고 시스템을 운용할 수도 있다.If the first compressor 120 or the first cooler 130 fails while the refrigerant cycle of the ship of the present embodiment is operated in an independent open loop, the first valve 191, the second valve 192, and the ninth The valve 201 and the twelfth valve 205 are closed, the sixth valve 196 is opened, and the boil-off gas passed through the first heat exchanger 110 after being discharged from the storage tank T receives the third valve ( 193), additional compressor 124, additional cooler 134, second compressor 122, second cooler 132, fourth valve 194 and sixth valve 196 to fuel demand 180 To be supplied. When it is necessary to use the evaporated gas compressed by the additional compressor 124 and the second compressor 122 as the refrigerant of the second heat exchanger 140, the ninth valve 201 and the twelfth valve 205 are used. You can also open and operate the system.
도 6은 본 발명의 제5 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.Figure 6 is a schematic diagram showing a system for treating the boil-off gas in accordance with a fifth embodiment of the present invention.
도 6에 도시된 제5 실시예의 선박은, 도 5에 도시된 제4 실시예의 선박에 비해, 제1 추가라인(L6)을 포함하지 않고, 추가압축기(124) 및 추가냉각기(134)를 재순환라인(L5)에 설치하며, 각 라인의 연결 위치가 약간씩 변경되었다는 점에서 차이점이 존재하며, 이하에서는 차이점을 위주로 설명한다. 전술한 제4 실시예의 선박과 동일한 부재에 대하여는 자세한 설명은 생략한다.The vessel of the fifth embodiment shown in FIG. 6 does not include the first additional line L6 and recycles the additional compressor 124 and the additional cooler 134 as compared to the vessel of the fourth embodiment shown in FIG. 5. Installed in the line (L5), there is a difference in that the connection position of each line is slightly changed, the following will be mainly described the difference. Detailed description of the same members as those of the ship of the fourth embodiment is omitted.
도 6을 참조하면, 본 실시예의 선박은, 제4 실시예와 마찬가지로, 제1 열교환기(110), 제1 밸브(191), 제1 압축기(120), 제1 냉각기(130), 제2 밸브(192), 제3 밸브(193), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194), 추진압축기(126), 추진냉각기(136), 제2 열교환기(140), 냉매감압장치(160), 추가압축기(124), 추가냉각기(134), 제9 밸브(201), 제12 밸브(205), 및 제1 감압장치(150)를 포함한다.Referring to FIG. 6, the vessel of the present embodiment, like the fourth embodiment, includes the first heat exchanger 110, the first valve 191, the first compressor 120, the first cooler 130, and the second. Valve 192, third valve 193, second compressor 122, second cooler 132, fourth valve 194, propulsion compressor 126, propulsion cooler 136, second heat exchanger ( 140, a refrigerant pressure reducing device 160, an additional compressor 124, an additional cooler 134, a ninth valve 201, a twelfth valve 205, and a first pressure reducing device 150.
본 실시예의 제1 열교환기(110)는, 제4 실시예와 마찬가지로, 저장탱크(T)로부터 배출된 증발가스를 냉매로 사용하여, 복귀라인(L3)을 따라 제1 열교환기(110)로 보내진 증발가스를 냉각시킨다. 즉, 제1 열교환기(110)는, 저장탱크(T)로부터 배출된 증발가스의 냉열을 회수하여, 회수한 냉열을 복귀라인(L3)을 따라 제1 열교환기(110)로 보내진 증발가스에 공급한다. 복귀라인(L3) 상에는 증발가스의 유량 및 개폐를 조절하는 제5 밸브(195)가 설치될 수 있다.Similar to the fourth embodiment, the first heat exchanger 110 according to the present embodiment uses the evaporated gas discharged from the storage tank T as the refrigerant and goes to the first heat exchanger 110 along the return line L3. Cool the sent boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the boil-off gas discharged from the storage tank T, and recovers the collected cold heat to the boil-off gas sent to the first heat exchanger 110 along the return line L3. Supply. A fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
본 실시예의 제1 압축기(120)는, 제4 실시예와 마찬가지로, 제1 공급라인(L1) 상에 설치되어 저장탱크(T)로부터 배출된 증발가스를 압축시키고, 본 실시예의 제2 압축기(122)는, 제4 실시예와 마찬가지로, 제2 공급라인(L2) 상에 제1 압축기(120)와 병렬로 설치되어 저장탱크(T)로부터 배출된 증발가스를 압축시킨다. 제1 압축기(120)와 제2 압축기(122)는, 동일한 성능의 압축기일 수 있고, 각각 다단압축기일 수 있다.The first compressor 120 of the present embodiment, like the fourth embodiment, is installed on the first supply line L1 to compress the evaporated gas discharged from the storage tank T, and the second compressor of the present embodiment ( As in the fourth embodiment, 122 is installed in parallel with the first compressor 120 on the second supply line L2 to compress the boil-off gas discharged from the storage tank T. The first compressor 120 and the second compressor 122 may be compressors of the same performance, and may each be a multistage compressor.
본 실시예의 제1 압축기(120) 및 제2 압축기(122)는, 제4 실시예와 마찬가지로, 연료수요처(180)가 요구하는 압력으로 증발가스를 압축시킬 수 있다. 또한, 연료수요처(180)가 여러 종류의 엔진을 포함하는 경우에는, 더 높은 압력을 요구하는 엔진(이하, '고압 엔진'이라고 함.)의 요구 압력에 맞추어 증발가스를 압축한 후 일부는 고압 엔진으로 공급하고, 다른 일부는 더 낮은 압력을 요구하는 엔진(이하, '저압 엔진'이라고 함.) 상류에 설치된 감압장치에 의해 감압시킨 후 저압 엔진으로 공급할 수 있다. 그 밖에도, 제1 열교환기(110) 및 제2 열교환기(140)에서의 재액화 효율 및 재액화량을 높이기 위하여, 증발가스를 제1 압축기(120) 또는 제2 압축기(122)에 의해 연료수요처(180)가 요구하는 압력 이상의 고압으로 압축시키고, 연료수요처(180) 상류에는 감압장치를 설치하여, 고압으로 압축된 증발가스의 압력을 연료수요처(180)가 요구하는 압력까지 낮춘 후에 연료수요처(180)로 공급할 수도 있다.Like the fourth embodiment, the first compressor 120 and the second compressor 122 of the present embodiment can compress the boil-off gas to the pressure required by the fuel demand 180. In addition, when the fuel demand unit 180 includes several types of engines, some of the high pressures are compressed after compressing the boil-off gas in accordance with a required pressure of an engine requiring higher pressure (hereinafter, referred to as a 'high pressure engine'). It can be supplied to the engine, and the other part can be supplied to the low pressure engine after being depressurized by a pressure reducing device installed upstream of the engine requiring a lower pressure (hereinafter referred to as a 'low pressure engine'). In addition, in order to increase the reliquefaction efficiency and the amount of reliquefaction in the first heat exchanger 110 and the second heat exchanger 140, the boil-off gas is fueled by the first compressor 120 or the second compressor 122. It is compressed to a high pressure higher than the pressure required by the customer 180, and a pressure reducing device is provided upstream of the fuel demand 180 to lower the pressure of the boiled gas compressed to high pressure to the pressure required by the fuel demand 180, and then the fuel demand. 180 may be supplied.
본 실시예의 선박은, 제4 실시예와 마찬가지로, 연료수요처(180) 상류에 설치되어, 연료수요처(180)로 보내지는 증발가스의 유량 및 개폐를 조절하는 제11 밸브(203)를 더 포함할 수 있다.The vessel of the present embodiment, like the fourth embodiment, further includes an eleventh valve 203 which is provided upstream of the fuel demand unit 180 and controls the flow rate and opening and closing of the boil-off gas sent to the fuel demand unit 180. Can be.
본 실시예의 선박은, 제4 실시예와 마찬가지로, 제2 압축기(122)에 의해 압축된 증발가스를 제2 열교환기(140)에서 증발가스를 추가적으로 냉각시키는 냉매로 사용하므로, 재액화 효율 및 재액화량을 높일 수 있다.As in the fourth embodiment, the vessel of the present embodiment uses the evaporated gas compressed by the second compressor 122 as a refrigerant for additionally cooling the evaporated gas in the second heat exchanger 140, and thus the re-liquefaction efficiency and The amount of liquefaction can be increased.
본 실시예의 제1 냉각기(130)는, 제4 실시예와 마찬가지로, 제1 압축기(120) 하류에 설치되어, 제1 압축기(120)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시키며, 본 실시예의 제2 냉각기(132)는, 제4 실시예와 마찬가지로, 제2 압축기(122) 하류에 설치되어, 제2 압축기(122)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시킨다.The first cooler 130 of the present embodiment, like the fourth embodiment, is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 and having risen in pressure and temperature, Similar to the fourth embodiment, the second cooler 132 of the present embodiment is installed downstream of the second compressor 122 to cool the evaporated gas that passes not only the pressure but also the temperature through the second compressor 122.
본 실시예의 추진압축기(126)는, 제4 실시예와 마찬가지로, 제1 공급라인(L1)을 따라 연료수요처(180)로 공급되는 증발가스의 일부를 분기시켜 제1 열교환기(110)로 보내는, 복귀라인(L3) 상에 설치되어, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되는 증발가스의 압력을 높인다. 추진압축기(126)는, 증발가스를 임계점(메탄의 경우, 대략 55 bar) 이하의 압력까지 압축시킬 수도 있고, 임계점을 초과하는 압력까지 압축시킬 수도 있으며, 본 실시예의 추진압축기(126)가 증발가스를 임계점 이상까지 압축시키는 경우, 대략 300 bar로 압축시킬 수 있다.Similar to the fourth embodiment, the propulsion compressor 126 of the present embodiment branches a part of the boil-off gas supplied to the fuel demand 180 along the first supply line L1 and sends it to the first heat exchanger 110. Is installed on the return line (L3), to increase the pressure of the boil-off gas supplied to the first heat exchanger (110) along the return line (L3). The propulsion compressor 126 may compress the boil-off gas to a pressure below the critical point (approximately 55 bar in the case of methane), or may compress it to a pressure above the critical point. If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.
본 실시예의 추진냉각기(136)는, 제4 실시예와 마찬가지로, 추진압축기(126) 하류의 복귀라인(L3) 상에 설치되어, 추진압축기(126)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스의 온도를 낮춘다.The propulsion cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126, similar to the fourth embodiment, and passes through the propulsion compressor 126 to increase not only the pressure but also the temperature. Lower the temperature.
본 실시예의 선박은, 추진압축기(126)를 더 포함하므로, 제4 실시예와 마찬가지로, 재액화 과정을 거치는 증발가스의 압력을 높여 재액화량 및 재액화 효율을 높일 수 있고, 제2 압축기(122)의 사용 빈도를 줄일 수 있어 리던던시의 개념을 충분히 확보할 수 있으며, 추진압축기(126)를 설치하지 않는 경우에 비해 운용 비용을 절약할 수 있다.Since the ship of the present embodiment further includes a propulsion compressor 126, like the fourth embodiment, the pressure of the boil-off gas undergoing the reliquefaction process can be increased to increase the amount of reliquefaction and reliquefaction efficiency, and the second compressor ( The use frequency of 122) can be reduced, so that the concept of redundancy can be sufficiently secured, and operating costs can be saved as compared with the case where the propulsion compressor 126 is not installed.
본 실시예의 제2 열교환기(140)는, 제4 실시예와 마찬가지로, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되어, 제1 열교환기(110)에 의해 냉각된 증발가스를 추가적으로 냉각시킨다.The second heat exchanger 140 of the present embodiment, like the fourth embodiment, is supplied to the first heat exchanger 110 along the return line L3 and cooled by the first heat exchanger 110. Cool additionally.
본 실시예에 의하면, 제4 실시예와 마찬가지로, 저장탱크(T)로부터 배출된 증발가스가 제1 열교환기(110)뿐만 아니라 제2 열교환기(140)에서도 추가적으로 냉각되어, 더 온도가 낮은 상태로 제1 감압장치(150)로 공급될 수 있으므로, 재액화 효율 및 재액화량이 높아지게 된다.According to the present embodiment, as in the fourth embodiment, the evaporated gas discharged from the storage tank T is additionally cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, so that the temperature is lower. Furnace can be supplied to the first decompression device 150, the re-liquefaction efficiency and the amount of re-liquefaction is increased.
본 실시예의 냉매감압장치(160)는, 제4 실시예와 마찬가지로, 제2 열교환기(140)를 통과한 증발가스를 팽창시킨 후 다시 제2 열교환기(140)로 보낸다.The refrigerant pressure reducing device 160 according to the present embodiment expands the boil-off gas passing through the second heat exchanger 140 and sends it to the second heat exchanger 140 in the same manner as in the fourth embodiment.
본 실시예의 추가압축기(124)는, 냉매감압장치(160) 및 제2 열교환기(140)를 통과한 유체를 압축시키며, 냉매감압장치(160)가 유체를 팽창시키면서 생산하는 동력에 의해 구동된다. 즉, 본 실시예의 냉매감압장치(160)와 추가압축기(124)는 압신기(Compander, 900)를 형성할 수 있다. 추가압축기(124)는, 제2 압축기(122)보다 더 작은 용량을 가질 수 있고, 냉매감압장치(160)가 생산하는 동력에 의해 구동될 수 있는 용량일 수 있다.The additional compressor 124 of the present embodiment compresses the fluid passing through the refrigerant reducing device 160 and the second heat exchanger 140, and is driven by the power generated by the refrigerant reducing device 160 while expanding the fluid. . That is, the refrigerant pressure reducing device 160 and the additional compressor 124 of the present embodiment may form a compander 900. The additional compressor 124 may have a smaller capacity than the second compressor 122 and may be a capacity that can be driven by the power produced by the refrigerant pressure reducing device 160.
단, 본 실시예의 추가압축기(124)는, 제4 실시예와는 달리, 제2 공급라인(L2) 상에 설치되는 것이 아니라, 제2 공급라인(L2)으로부터 분기되어 냉매감압장치(160) 및 제2 열교환기(140)를 통과한 유체가, 다시 제2 공급라인(L2)으로 보내지는 재순환라인(L5) 상에 설치된다.However, unlike the fourth embodiment, the additional compressor 124 of the present embodiment is not installed on the second supply line L2, but branched from the second supply line L2 to reduce the refrigerant pressure reducing device 160. And the fluid passing through the second heat exchanger 140 is installed on the recirculation line L5 which is sent to the second supply line L2 again.
본 실시예에 의하면, 제4 실시예와 마찬가지로, 냉매감압장치(160)가 생산하는 동력을 활용할 수 있고, 제2 압축기(122)보다 더 작은 용량의 추가압축기(124)를 추가함으로써 적은 비용으로 재액화 효율 및 재액화량을 높일 수 있다. According to the present embodiment, as in the fourth embodiment, the power generated by the refrigerant pressure reducing device 160 can be utilized, and the additional compressor 124 having a smaller capacity than the second compressor 122 can be added at a low cost. Reliquefaction efficiency and amount of reliquefaction can be raised.
본 실시예의 추가냉각기(134)는, 제4 실시예와 마찬가지로, 추가압축기(124) 하류에 설치되어, 추가압축기(124)에 의해 압축되며 압력뿐만 아니라 온도도 높아진 증발가스의 온도를 낮춘다. 단, 본 실시예의 추가냉각기(134)는, 제4 실시예와는 달리, 재순환라인(L5) 상에 설치된다.The additional cooler 134 of this embodiment, like the fourth embodiment, is installed downstream of the additional compressor 124 to lower the temperature of the boil-off gas compressed by the additional compressor 124 and whose temperature as well as the pressure is increased. However, unlike the fourth embodiment, the additional cooler 134 of the present embodiment is installed on the recirculation line L5.
본 실시예에서는, 추가압축기(124)와 추가냉각기(134)를 재순환라인(L5) 상에 설치하여, 제2 열교환기(140)에서 냉매로 사용되는 유체가, 제4 실시예의 폐루프 냉매 사이클과 동일한 경로를 순환할 수 있도록 하면서도, 제1 압축기(120) 또는 제1 냉각기(130)가 고장난 경우, 제4 실시예보다 용이하게 제2 압축기(122) 및 제2 냉각기(132)를 통과한 증발가스를 연료수요처(180)에 연료로 공급할 수 있다.In this embodiment, the additional compressor 124 and the additional cooler 134 are installed on the recirculation line L5 so that the fluid used as the refrigerant in the second heat exchanger 140 is the closed loop refrigerant cycle of the fourth embodiment. When the first compressor 120 or the first cooler 130 is broken, the second compressor 122 and the second cooler 132 that pass through the second compressor 122 and the second cooler 132 are more easily than the fourth embodiment. The boil-off gas may be supplied as fuel to the fuel demand unit 180.
이하, 제1 압축기(120) 및 제1 냉각기(130)가 정상적으로 동작하는 경우를 '평상시'라고 하고, 제1 압축기(120) 또는 제1 냉각기(130)가 고장난 경우를 '비상시'라고 한다.Hereinafter, the case in which the first compressor 120 and the first cooler 130 operate normally will be referred to as 'normal', and the case where the first compressor 120 or the first cooler 130 is broken will be referred to as 'emergency'.
즉, 본 실시예에 의하면, 제2 열교환기(140)에서 냉매로 사용되는 유체가, 재순환라인(L5) 및 제2 공급라인(L2)을 따라, 추가압축기(124), 추가냉각기(134), 제2 압축기(122), 제2 냉각기(132), 제2 열교환기(140), 냉매감압장치(160), 및 다시 제2 열교환기(140)를 지난 후 다시 추가압축기(124)로 보내지므로, 제4 실시예의 폐루프 냉매 사이클과 동일한 냉매 사이클을 순환한다.That is, according to this embodiment, the fluid used as the refrigerant in the second heat exchanger 140, along the recirculation line (L5) and the second supply line (L2), the additional compressor 124, the additional cooler 134. After passing through the second compressor 122, the second cooler 132, the second heat exchanger 140, the refrigerant pressure reducing device 160, and the second heat exchanger 140 again, the second compressor 122 is sent to the additional compressor 124. Therefore, the same refrigerant cycle as the closed loop refrigerant cycle of the fourth embodiment is circulated.
한편, 제4 실시예에 의하면, 비상시 제2 공급라인(L2)을 따라 연료수요처(180)로 공급되는 증발가스는, 추가압축기(124) 및 제2 압축기(122) 모두에 의해 압축된 후 연료수요처(180)로 공급되므로, 제2 압축기(122)가 제1 압축기(120)와 동일한 성능을 가지는 경우, 비상시 제2 공급라인(L2)을 따라 연료수요처(180)로 공급되는 증발가스의 압력이, 평상시 제1 공급라인(L1)을 따라 연료수요처(180)로 공급되는 증발가스의 압력보다 높을 수 있다.On the other hand, according to the fourth embodiment, the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in an emergency is compressed by both the additional compressor 124 and the second compressor 122 and then the fuel. Since the second compressor 122 has the same performance as the first compressor 120 because it is supplied to the demand destination 180, the pressure of the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in an emergency. In this case, the pressure may be higher than the pressure of the boil-off gas supplied to the fuel demand 180 along the first supply line L1.
따라서, 제4 실시예에 의하면, 비상시 제2 공급라인(L2)을 따라 연료수요처(180)로 공급되는 증발가스의 압력을, 평상시 제1 공급라인(L1)을 따라 연료수요처(180)로 공급되는 증발가스의 압력과 동일하게 맞추기 위한, 별도의 제어가 필요하거나, 제2 압축기(122)를 리던던시로 활용하는 것이 곤란한 경우가 생길 수도 있다.Therefore, according to the fourth embodiment, the pressure of the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in an emergency is normally supplied to the fuel demand 180 along the first supply line L1. Separate control may be required to equalize the pressure of the boil-off gas, or it may be difficult to utilize the second compressor 122 as redundancy.
반면, 본 실시예에 의하면, 비상시 제2 공급라인(L2)을 따라 연료수요처(180)로 공급되는 증발가스는, 추가압축기(124)에 의해 압축되지 않고 제2 압축기(122)에 의하여만 압축된 후 연료수요처(180)로 공급되므로, 제2 압축기(122)가 제1 압축기(120)와 동일한 성능을 가지는 경우, 비상시 추가적인 압력 조절 없이 용이하게 제2 공급라인(L2)을 통해 연료수요처(180)로 증발가스를 공급할 수 있다.On the other hand, according to the present embodiment, the boil-off gas supplied to the fuel demand 180 along the second supply line L2 in the emergency is not compressed by the additional compressor 124 but compressed only by the second compressor 122. After the second compressor 122 has the same performance as the first compressor 120, since the second compressor 122 has the same performance as that of the first compressor 120, the fuel demand source (L2) can be easily provided through the second supply line L2 without additional pressure adjustment in an emergency. 180) can be supplied to the boil-off gas.
본 실시예의 제1 감압장치(150)는, 제4 실시예와 마찬가지로, 복귀라인(L3) 상에 설치되어, 제1 열교환기(110) 및 제2 열교환기(140)에 의해 냉각된 증발가스를 팽창시킨다. 본 실시예의 제1 감압장치(150)는, 증발가스를 팽창시켜 냉각시킬 수 있는 모든 수단을 포함하며, 줄-톰슨(Joule-Thomson) 밸브 등의 팽창밸브, 또는 팽창기일 수 있다.The first pressure reducing device 150 of the present embodiment, like the fourth embodiment, is installed on the return line L3 and is cooled by the first heat exchanger 110 and the second heat exchanger 140. Inflate. The first pressure reducing device 150 of the present embodiment includes all means capable of expanding and cooling the boil-off gas, and may be an expansion valve such as a Joule-Thomson valve or an expander.
본 실시예의 선박은, 제4 실시예와 마찬가지로, 제1 감압장치(150) 하류의 복귀라인(L3) 상에 설치되며 제1 감압장치(150)으로부터 배출되는 기액 혼합물을 기체와 액체로 분리하는, 기액분리기(170)를 포함할 수 있다.The vessel of this embodiment, like the fourth embodiment, is installed on the return line L3 downstream of the first pressure reducing device 150 and separates the gas-liquid mixture discharged from the first pressure reducing device 150 into gas and liquid. , Gas-liquid separator 170 may be included.
제4 실시예와 마찬가지로, 본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는 제1 감압장치(150)를 통과한 액체 또는 기액혼합 상태의 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는 제1 감압장치(150)를 통과한 증발가스는 기액분리기(170)로 보내져, 기체상과 액체상이 분리된다. 기액분리기(170)에 의해 분리된 액체는 복귀라인(L3)을 따라 저장탱크(T)로 복귀하고, 기액분리기(170)에 의해 분리된 기체는, 기액분리기(170)로부터 제1 열교환기(110) 상류의 제1 공급라인(L1)까지 연장되는 기체배출라인(L4)을 따라, 제1 열교환기(110)으로 공급된다.As in the fourth embodiment, when the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or gaseous-mixed evaporated gas that has passed through the first pressure reducing device 150 is directly sent to the storage tank T. When the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first pressure reducing device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
본 실시예의 선박이 기액분리기(170)를 포함하는 경우, 제4 실시예와 마찬가지로, 기액분리기(170)에 의해 분리되어 저장탱크(T)로 보내지는 액체의 유량을 조절하는 제7 밸브(197); 및 기액분리기(170)에 의해 분리되어 제1 열교환기(110)로 보내지는 기체의 유량을 조절하는 제8 밸브(198);를 더 포함할 수 있다.When the vessel of the present embodiment includes the gas-liquid separator 170, like the fourth embodiment, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T) ); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
단, 본 실시예의 선박은, 제4 실시예와는 달리, 제1 추가라인(L6)을 포함하지 않고, 제1 공급라인(L1)으로부터 분기한 제2 공급라인(L2)이 재순환라인(L5)이 아닌 제1 공급라인(L1)과 다시 합류된다. 또한, 재순환라인(L5)이, 제1 공급라인(L1)이 아닌 제2 냉각기(132)와 제4 밸브(194) 사이의 제2 공급라인(L2)으로부터 분기된 후, 제1 공급라인(L1)이 아닌 제3 밸브(193)와 제2 압축기(122) 사이의 제2 공급라인(L2)과 다시 합류된다.However, unlike the fourth embodiment, the ship of the present embodiment does not include the first additional line L6, and the second supply line L2 branched from the first supply line L1 is the recirculation line L5. Is joined again with the first supply line L1. In addition, after the recirculation line L5 branches from the second supply line L2 between the second cooler 132 and the fourth valve 194 instead of the first supply line L1, the first supply line ( The second supply line (L2) between the third valve (193) and the second compressor (122) instead of L1 is again joined.
또한, 본 실시예의 선박은, 제4 실시예와는 달리 제6 밸브(196)를 포함하지 않는다.In addition, the ship of this embodiment, unlike the fourth embodiment, does not include the sixth valve 196.
본 실시예에서는 제1 열교환기(110)를 포함하여, 저장탱크(T)로부터 배출된 증발가스가 제1 열교환기(110)에서 열교환된 후 제1 압축기(120) 또는 제2 압축기(122)로 공급되는 경우를 설명하였으나, 본 발명의 선박은, 제1 열교환기(110)를 포함하지 않고, 저장탱크(T)로부터 배출된 증발가스는 바로 제1 압축기(120) 또는 제2 압축기(122)로 공급되고, 복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스는, 추진압축기(126)에 의해 압축된 후 바로 제2 열교환기(140)로 보내질 수도 있다. 후술할 제6 실시예도 동일하다.In the present embodiment, including the first heat exchanger 110, the evaporated gas discharged from the storage tank (T) after the heat exchange in the first heat exchanger 110, the first compressor 120 or the second compressor 122 Although it was described that the case is supplied to the, the vessel of the present invention does not include the first heat exchanger 110, the evaporated gas discharged from the storage tank (T) is immediately the first compressor 120 or the second compressor (122). ) And the evaporated gas undergoing the reliquefaction process along the return line L3 may be sent to the second heat exchanger 140 immediately after being compressed by the propulsion compressor 126. The same applies to the sixth embodiment to be described later.
또한, 본 실시예에서는 재순환라인(L5)을 따라 순환하는 유체가 제2 열교환기(140)를 1차로 통과하고 냉매감압장치(160)에 의해 팽창된 후 다시 제2 열교환기(140)로 공급되는 경우를 설명하였으나, 본 발명의 재순환라인(L5)을 따라 순환하는 유체는, 제2 공급라인(L2)으로부터 분기된 후 바로 냉매감압장치(160)에 의해 팽창된 후 제2 열교환기(140)로 보내질 수도 있다. 후술할 제6 실시예도 동일하다.In addition, in the present embodiment, the fluid circulating along the recirculation line L5 passes through the second heat exchanger 140 firstly, is expanded by the refrigerant pressure reducing device 160, and is then supplied to the second heat exchanger 140 again. Although the case has been described, the fluid circulating along the recirculation line (L5) of the present invention, after being branched from the second supply line (L2) is expanded by the refrigerant pressure reducing device 160 immediately after the second heat exchanger (140) May be sent as). The same applies to the sixth embodiment to be described later.
본 실시예의 제1 내지 제5 밸브, 제7 내지 제9 밸브, 제11 밸브, 및 제12 밸브(191, 192, 193, 194, 195, 197, 198, 201, 203, 205)는, 시스템 운용 상황을 사람이 직접 판단하여 수동으로 조절될 수도 있고, 미리 설정된 값에 의해 개폐되도록 자동으로 조절될 수도 있다.The first to fifth valves, the seventh to ninth valves, the eleventh valves, and the twelfth valves 191, 192, 193, 194, 195, 197, 198, 201, 203, and 205 of the present embodiment operate the system. The situation may be manually adjusted by a person directly and may be automatically adjusted to be opened or closed by a preset value.
본 실시예의 냉매 사이클은 폐루프로 운용되는 것이 바람직하며, 이하, 밸브 조절을 통해 본 실시예의 냉매 사이클을 폐루프로 운용하는 방법을 설명한다.The refrigerant cycle of the present embodiment is preferably operated in a closed loop, hereinafter, a method of operating the refrigerant cycle of the present embodiment in a closed loop by adjusting a valve will be described.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하기 위해서, 일단, 제1 밸브(191), 제2 밸브(192), 제3 밸브(193), 제4 밸브(194), 제5 밸브(195), 제9 밸브(201), 및 제12 밸브(205)를 연 상태에서 시스템을 구동시킨다.In order to operate the refrigerant cycle of the ship of this embodiment as a closed loop, once, the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the fifth valve 195. ), The ninth valve 201 and the twelfth valve 205 are opened to drive the system.
저장탱크(T)로부터 배출된 후 제2 압축기(122)에 의해 압축된 증발가스가 재순환라인(L5)으로 공급되면, 제3 밸브(193) 및 제4 밸브(194)를 닫아, 증발가스가 제2 압축기(122), 제2 냉각기(132), 제12 밸브(205), 제2 열교환기(140), 냉매감압장치(160), 다시 제2 열교환기(140), 추가압축기(124), 추가냉각기(134), 및 제9 밸브(201)를 순환하는, 폐루프의 냉매 사이클을 형성시킨다.When the boil-off gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recirculation line L5, the third valve 193 and the fourth valve 194 are closed to produce the boil-off gas. Second compressor 122, second cooler 132, twelfth valve 205, second heat exchanger 140, refrigerant pressure reducing device 160, second heat exchanger 140, and additional compressor 124. And a closed loop refrigerant cycle circulating through the additional cooler 134 and the ninth valve 201.
냉매 사이클을 폐루프로 구성하는 경우에는, 질소가스를 폐루프를 순환하는 냉매로 사용할 수도 있다. 이 경우, 본 실시예의 저장탱크(T)를 포함하는 저장탱크(T)는, 질소가스를 폐루프의 냉매 사이클 내로 도입시키는 배관을 더 포함할 수 있다.When the refrigerant cycle is configured as a closed loop, nitrogen gas may be used as the refrigerant circulating in the closed loop. In this case, the storage tank T including the storage tank T of the present embodiment may further include a pipe for introducing nitrogen gas into the refrigerant cycle of the closed loop.
냉매 사이클이 폐루프로 운용되는 경우, 폐루프를 순환하는 증발가스만이 제2 열교환기(140)에서의 냉매로 사용되며, 제1 압축기(120)를 통과한 증발가스는 냉매 사이클로 도입되지 못하고 연료수요처(180)로 공급되거나, 복귀라인(L3)을 따라 재액화 과정을 거치게 된다. 따라서, 재액화량이나, 연료수요처(180)에서 요구하는 증발가스량에 무관하게 일정한 유량의 증발가스가 제2 열교환기(140)의 냉매로 순환된다.When the refrigerant cycle is operated as a closed loop, only the boil-off gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the boil-off gas passing through the first compressor 120 cannot be introduced into the refrigerant cycle. It is supplied to the fuel demand 180, or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction or the amount of boil-off gas required by the fuel demand unit 180, the boil-off gas of a constant flow rate is circulated to the refrigerant of the second heat exchanger 140.
본 실시예의 냉매 사이클이 폐루프로 운용되는 경우, 개루프 또는 독립 개루프로 운용되는 경우에 비해, 재액화 과정을 거치는 증발가스와 냉매로 사용되는 증발가스 각각의 유량을 제어하기가 용이하다는 장점이 있다.When the refrigerant cycle of the present embodiment is operated in a closed loop, it is easier to control the flow rate of each of the evaporated gas that is undergoing the reliquefaction process and the evaporated gas used as the refrigerant compared to the case of operating the closed loop or the independent open loop. There is this.
본 실시예의 선박의 냉매 사이클이 폐루프로 운용되는 경우의 증발가스의 흐름을 설명하면 다음과 같다.Referring to the flow of the boil-off gas when the refrigerant cycle of the ship of the present embodiment is operated in a closed loop as follows.
저장탱크(T)로부터 배출된 증발가스는 제1 열교환기(110)를 통과한 후 제1 압축기(120)에 의해 압축되고 제1 냉각기(130)에 의해 냉각된 후 일부는 연료수요처(180)로 보내지고, 나머지 일부는 복귀라인(L3)을 따라 재액화 과정을 거치게 된다.The boil-off gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, and a part of the fuel demand unit 180 is removed. The remaining part is subjected to the reliquefaction process along the return line (L3).
저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스는 대략 1 bar 일 수 있고, 대략 1 bar의 증발가스는 제1 압축기(120)에 의해 압축되어 대략 17 bar가 될 수 있다. 제1 압축기(120)에 의해 압축된 증발가스의 압력은, 시스템이 요구하는 재액화 성능 및 시스템의 운용 상황에 따라 달라질 수 있다.The evaporated gas passed through the first heat exchanger 110 after being discharged from the storage tank T may be about 1 bar, and about 1 bar of the evaporated gas may be compressed by the first compressor 120 so that approximately 17 bar may be Can be. The pressure of the boil-off gas compressed by the first compressor 120 may vary depending on the reliquefaction performance required by the system and the operating situation of the system.
복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스는, 추진압축기(126)에 의해 압축되고 추진냉각기(136)에 의해 냉각된 후, 제1 열교환기(110)에 의해 저장탱크(T)로부터 배출된 증발가스와 열교환되어 냉각된다. 제1 열교환기(110)에 의해 냉각된 증발가스는, 제2 열교환기(140)에서 열교환되어 추가적으로 냉각된 후 제1 감압장치(150)에 의해 팽창되어 일부 또는 전부가 재액화된다.The boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled. The boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는, 일부 또는 전부 재액화된 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는, 일부 또는 전부 재액화된 증발가스는 기액분리기(170)로 보내진다. 기액분리기(170)에 의해 분리된 기체는, 저장탱크(T)로부터 배출되는 증발가스와 합류되어 제1 열교환기(110)로 보내지고, 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 보내진다.When the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
한편, 냉매 사이클을 순환하는 증발가스는, 추가압축기(124)에 의해 압축되고 추가냉각기(134)에 의해 냉각된 후, 제2 압축기(122)에 의해 추가적으로 압축되고 제2 냉각기(132)에 의해 냉각되어, 재순환라인(L5)을 따라 제2 열교환기(140)로 보내진다. 추가압축기(124) 및 제2 압축기(122)를 통과한 후 제2 열교환기(140)로 보내진 증발가스는, 제2 열교환기(140)에서 1차로 열교환되어 냉각된 후 냉매감압장치(160)로 보내져 2차로 팽창되어 냉각된다.On the other hand, the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the second compressor 122 and by the second cooler 132. Cooled and sent to the second heat exchanger 140 along the recycle line (L5). After passing through the additional compressor 124 and the second compressor 122, the boil-off gas sent to the second heat exchanger 140 is first heat-exchanged by the second heat exchanger 140, and then cooled. It is sent to the secondary expansion and cooled.
추가압축기(124)에 의해 압축된 증발가스는 대략 2 bar일 수 있고, 대략 2 bar의 증발가스는 제2 압축기(122)에 의해 압축되어 대략 32 bar가 될 수 있다. 추가압축기(124)에 의해 압축된 증발가스의 압력 및 제2 압축기(122)에 의해 압축된 증발가스의 압력은, 시스템이 요구하는 재액화 성능 및 시스템의 운용 상황에 따라 달라질 수 있다.The boil-off gas compressed by the additional compressor 124 may be about 2 bar, and the boil-off gas of about 2 bar may be compressed by the second compressor 122 to be about 32 bar. The pressure of the boil-off gas compressed by the additional compressor 124 and the pressure of the boil-off gas compressed by the second compressor 122 may vary depending on the reliquefaction performance required by the system and the operating conditions of the system.
냉매감압장치(160)를 통과한 증발가스는 다시 제2 열교환기(140)로 보내져, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급된 증발가스; 및 추가압축기(124)와 제2 압축기(122)에 의해 압축된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 공급된 증발가스;를 냉각시키는 냉매로 사용된다. 냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 냉매로 사용된 증발가스는, 다시 추가압축기(124)로 보내져 상술한 일련의 과정을 반복한다.The evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
본 실시예의 선박의 냉매 사이클이 폐루프로 운용되는 도중, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나게 되면, 제1 밸브(191), 제2 밸브(192), 제9 밸브(201), 및 제12 밸브(205)는 닫고, 제3 밸브(193) 및 제4 밸브(194)는 열어, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스가, 제3 밸브(193), 제2 압축기(122), 제2 냉각기(132), 및 제4 밸브(194)를 거쳐 연료수요처(180)로 공급되도록 한다.If the first compressor 120 or the first cooler 130 fails while the refrigerant cycle of the ship of the present embodiment is operated in a closed loop, the first valve 191, the second valve 192, and the ninth valve are damaged. 201 and the 12th valve 205 are closed, the 3rd valve 193 and the 4th valve 194 are opened, the evaporation which passed through the 1st heat exchanger 110 after discharge | emission from the storage tank T is carried out. The gas is supplied to the fuel demand 180 through the third valve 193, the second compressor 122, the second cooler 132, and the fourth valve 194.
도 7은 본 발명의 제6 실시예에 따른 선박의 증발가스 처리 시스템을 개략적으로 나타낸 구성도이다.7 is a configuration diagram schematically showing a boil-off gas treatment system according to a sixth embodiment of the present invention.
도 7에 도시된 제6 실시예의 선박은, 도 6에 도시된 제5 실시예의 선박에 비해, 제2 추가라인(L11), 제2 추가라인(L11) 상에 설치되는 제13 밸브(206), 제3 추가라인(L12), 제3 추가라인(L12) 상에 설치되는 제14 밸브(207), 제4 추가라인(L13), 및 제4 추가라인(L13) 상에 설치되는 제15 밸브(208)를 더 포함한다는 점에서 차이점이 존재하며, 이하에서는 차이점을 위주로 설명한다. 전술한 제5 실시예의 선박과 동일한 부재에 대하여는 자세한 설명은 생략한다.The ship of the sixth embodiment shown in FIG. 7 has a second additional line L11 and a thirteenth valve 206 installed on the second additional line L11, compared to the ship of the fifth embodiment shown in FIG. 6. , The fifteenth valve 207 installed on the third additional line L12, the third additional line L12, the fourth additional line L13, and the fifteenth valve installed on the fourth additional line L13. Differences exist in that they further include (208), and the following description will focus on the differences. Detailed description of the same members as those of the ship of the fifth embodiment described above will be omitted.
도 7을 참조하면, 본 실시예의 선박은, 제5 실시예와 마찬가지로, 제1 열교환기(110), 제1 밸브(191), 제1 압축기(120), 제1 냉각기(130), 제2 밸브(192), 제3 밸브(193), 제2 압축기(122), 제2 냉각기(132), 제4 밸브(194), 추진압축기(126), 추진냉각기(136), 제2 열교환기(140), 냉매감압장치(160), 추가압축기(124), 추가냉각기(134), 제9 밸브(201), 제12 밸브(205), 및 제1 감압장치(150)를 포함한다.Referring to FIG. 7, the vessel of the present embodiment, like the fifth embodiment, includes the first heat exchanger 110, the first valve 191, the first compressor 120, the first cooler 130, and the second. Valve 192, third valve 193, second compressor 122, second cooler 132, fourth valve 194, propulsion compressor 126, propulsion cooler 136, second heat exchanger ( 140, a refrigerant pressure reducing device 160, an additional compressor 124, an additional cooler 134, a ninth valve 201, a twelfth valve 205, and a first pressure reducing device 150.
본 실시예의 제1 열교환기(110)는, 제5 실시예와 마찬가지로, 저장탱크(T)로부터 배출된 증발가스를 냉매로 사용하여, 복귀라인(L3)을 따라 제1 열교환기(110)로 보내진 증발가스를 냉각시킨다. 즉, 제1 열교환기(110)는, 저장탱크(T)로부터 배출된 증발가스의 냉열을 회수하여, 회수한 냉열을 복귀라인(L3)을 따라 제1 열교환기(110)로 보내진 증발가스에 공급한다. 복귀라인(L3) 상에는 증발가스의 유량 및 개폐를 조절하는 제5 밸브(195)가 설치될 수 있다.Similar to the fifth embodiment, the first heat exchanger 110 of the present embodiment uses the evaporated gas discharged from the storage tank T as the refrigerant, and then returns to the first heat exchanger 110 along the return line L3. Cool the sent boil-off gas. That is, the first heat exchanger 110 recovers the cold heat of the boil-off gas discharged from the storage tank T, and recovers the collected cold heat to the boil-off gas sent to the first heat exchanger 110 along the return line L3. Supply. A fifth valve 195 may be installed on the return line L3 to control the flow rate and opening and closing of the boil-off gas.
본 실시예의 제1 압축기(120)는, 제5 실시예와 마찬가지로, 제1 공급라인(L1) 상에 설치되어 저장탱크(T)로부터 배출된 증발가스를 압축시키고, 본 실시예의 제2 압축기(122)는, 제5 실시예와 마찬가지로, 제2 공급라인(L2) 상에 제1 압축기(120)와 병렬로 설치되어 저장탱크(T)로부터 배출된 증발가스를 압축시킨다. 제1 압축기(120)와 제2 압축기(122)는, 동일한 성능의 압축기일 수 있고, 각각 다단압축기일 수 있다.The first compressor 120 of the present embodiment, like the fifth embodiment, is installed on the first supply line L1 to compress the boil-off gas discharged from the storage tank T, and the second compressor of the present embodiment ( As in the fifth embodiment, 122 is installed in parallel with the first compressor 120 on the second supply line L2 to compress the boil-off gas discharged from the storage tank T. The first compressor 120 and the second compressor 122 may be compressors of the same performance, and may each be a multistage compressor.
본 실시예의 제1 압축기(120) 및 제2 압축기(122)는, 제5 실시예와 마찬가지로, 연료수요처(180)가 요구하는 압력으로 증발가스를 압축시킬 수 있다. 또한, 연료수요처(180)가 여러 종류의 엔진을 포함하는 경우에는, 더 높은 압력을 요구하는 엔진(이하, '고압 엔진'이라고 함.)의 요구 압력에 맞추어 증발가스를 압축한 후 일부는 고압 엔진으로 공급하고, 다른 일부는 더 낮은 압력을 요구하는 엔진(이하, '저압 엔진'이라고 함.) 상류에 설치된 감압장치에 의해 감압시킨 후 저압 엔진으로 공급할 수 있다. 그 밖에도, 제1 열교환기(110) 및 제2 열교환기(140)에서의 재액화 효율 및 재액화량을 높이기 위하여, 증발가스를 제1 압축기(120) 또는 제2 압축기(122)에 의해 연료수요처(180)가 요구하는 압력 이상의 고압으로 압축시키고, 연료수요처(180) 상류에는 감압장치를 설치하여, 고압으로 압축된 증발가스의 압력을 연료수요처(180)가 요구하는 압력까지 낮춘 후에 연료수요처(180)로 공급할 수도 있다.Like the fifth embodiment, the first compressor 120 and the second compressor 122 of the present embodiment can compress the boil-off gas to the pressure required by the fuel demand unit 180. In addition, when the fuel demand unit 180 includes several types of engines, some of the high pressures are compressed after compressing the boil-off gas in accordance with a required pressure of an engine requiring higher pressure (hereinafter, referred to as a 'high pressure engine'). It can be supplied to the engine, and the other part can be supplied to the low pressure engine after being depressurized by a pressure reducing device installed upstream of the engine requiring a lower pressure (hereinafter referred to as a 'low pressure engine'). In addition, in order to increase the reliquefaction efficiency and the amount of reliquefaction in the first heat exchanger 110 and the second heat exchanger 140, the boil-off gas is fueled by the first compressor 120 or the second compressor 122. It is compressed to a high pressure higher than the pressure required by the customer 180, and a pressure reducing device is provided upstream of the fuel demand 180 to lower the pressure of the boiled gas compressed to high pressure to the pressure required by the fuel demand 180, and then the fuel demand. 180 may be supplied.
본 실시예의 선박은, 제5 실시예와 마찬가지로, 연료수요처(180) 상류에 설치되어, 연료수요처(180)로 보내지는 증발가스의 유량 및 개폐를 조절하는 제11 밸브(203)를 더 포함할 수 있다.The ship of this embodiment, like the fifth embodiment, further includes an eleventh valve 203 which is provided upstream of the fuel demand unit 180 and regulates the flow rate and opening / closing of the boil-off gas sent to the fuel demand unit 180. Can be.
본 실시예의 제1 냉각기(130)는, 제5 실시예와 마찬가지로, 제1 압축기(120) 하류에 설치되어, 제1 압축기(120)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시키며, 본 실시예의 제2 냉각기(132)는, 제5 실시예와 마찬가지로, 제2 압축기(122) 하류에 설치되어, 제2 압축기(122)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스를 냉각시킨다.The first cooler 130 of the present embodiment, like the fifth embodiment, is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 and having risen in pressure and temperature, Similar to the fifth embodiment, the second cooler 132 of the present embodiment is installed downstream of the second compressor 122 to cool the evaporated gas that passes not only the pressure but also the temperature through the second compressor 122.
본 실시예의 추진압축기(126)는, 제5 실시예와 마찬가지로, 복귀라인(L3) 상에 설치되어, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되는 증발가스의 압력을 높인다. 추진압축기(126)는, 증발가스를 임계점(메탄의 경우, 대략 55 bar) 이하의 압력까지 압축시킬 수도 있고, 임계점을 초과하는 압력까지 압축시킬 수도 있으며, 본 실시예의 추진압축기(126)가 증발가스를 임계점 이상까지 압축시키는 경우, 대략 300 bar로 압축시킬 수 있다.The propulsion compressor 126 of the present embodiment, like the fifth embodiment, is installed on the return line L3 to increase the pressure of the boil-off gas supplied to the first heat exchanger 110 along the return line L3. . The propulsion compressor 126 may compress the boil-off gas to a pressure below the critical point (approximately 55 bar in the case of methane), or may compress it to a pressure above the critical point. If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.
본 실시예의 추진냉각기(136)는, 제5 실시예와 마찬가지로, 추진압축기(126) 하류의 복귀라인(L3) 상에 설치되어, 추진압축기(126)를 통과하며 압력뿐만 아니라 온도도 올라간 증발가스의 온도를 낮춘다.The propulsion cooler 136 of the present embodiment, like the fifth embodiment, is installed on the return line L3 downstream of the propulsion compressor 126 and passes through the propulsion compressor 126 to increase not only the pressure but also the temperature. Lower the temperature.
본 실시예의 선박은, 추진압축기(126)를 더 포함하므로, 제5 실시예와 마찬가지로, 재액화 과정을 거치는 증발가스의 압력을 높여 재액화량 및 재액화 효율을 높일 수 있고, 리던던시의 개념을 충분히 확보할 수 있으며, 운용 비용을 절약할 수 있다.Since the ship of the present embodiment further includes a propulsion compressor 126, similar to the fifth embodiment, the pressure of the boil-off gas undergoing the reliquefaction process can be increased to increase the amount of reliquefaction and reliquefaction, and the concept of redundancy It can be secured enough and the operating cost can be saved.
본 실시예의 제2 열교환기(140)는, 제5 실시예와 마찬가지로, 복귀라인(L3)을 따라 제1 열교환기(110)로 공급되어, 제1 열교환기(110)에 의해 냉각된 증발가스를 추가적으로 냉각시킨다.The second heat exchanger 140 of the present embodiment, like the fifth embodiment, is supplied to the first heat exchanger 110 along the return line L3 and cooled by the first heat exchanger 110. Cool additionally.
본 실시예에 의하면, 제5 실시예와 마찬가지로, 저장탱크(T)로부터 배출된 증발가스가 제1 열교환기(110)뿐만 아니라 제2 열교환기(140)에서도 추가적으로 냉각되어, 더 온도가 낮은 상태로 제1 감압장치(150)로 공급될 수 있으므로, 재액화 효율 및 재액화량이 높아지게 된다.According to this embodiment, as in the fifth embodiment, the boil-off gas discharged from the storage tank T is additionally cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, so that the temperature is lower. Furnace can be supplied to the first decompression device 150, the re-liquefaction efficiency and the amount of re-liquefaction is increased.
본 실시예의 냉매감압장치(160)는, 제5 실시예와 마찬가지로, 제2 열교환기(140)를 통과한 증발가스를 팽창시킨 후 다시 제2 열교환기(140)로 보낸다.The refrigerant pressure reducing device 160 according to the present embodiment expands the evaporated gas passing through the second heat exchanger 140 and sends it to the second heat exchanger 140 in the same manner as in the fifth embodiment.
본 실시예의 추가압축기(124)는, 제5 실시예와 마찬가지로, 재순환라인(L5) 상에 설치되어, 냉매감압장치(160) 및 제2 열교환기(140)를 통과한 유체를 압축시킨다. 또한, 본 실시예의 추가압축기(124)는, 제5 실시예와 마찬가지로, 냉매감압장치(160)가 유체를 팽창시키면서 생산하는 동력에 의해 구동되며, 냉매감압장치(160)와 추가압축기(124)는 압신기(Compander, 900)를 형성할 수 있다. 추가압축기(124)는, 제2 압축기(122)보다 더 작은 용량을 가질 수 있고, 냉매감압장치(160)가 생산하는 동력에 의해 구동될 수 있는 용량일 수 있다.The additional compressor 124 of the present embodiment, like the fifth embodiment, is installed on the recirculation line L5 to compress the fluid passing through the refrigerant pressure reducing device 160 and the second heat exchanger 140. In addition, the additional compressor 124 of the present embodiment, like the fifth embodiment, is driven by the power generated by the refrigerant pressure reducing device 160 while expanding the fluid, and the refrigerant pressure reducing device 160 and the additional compressor 124 are used. May form a compander 900. The additional compressor 124 may have a smaller capacity than the second compressor 122 and may be a capacity that can be driven by the power produced by the refrigerant pressure reducing device 160.
본 실시예에 의하면, 제5 실시예와 마찬가지로, 냉매감압장치(160)가 생산하는 동력을 활용할 수 있고, 제1 압축기(120) 또는 제2 압축기(122)보다 더 작은 용량의 추가압축기(124)를 추가함으로써 적은 비용으로 재액화 효율 및 재액화량을 높일 수 있다.According to the present embodiment, like the fifth embodiment, the additional pressure compressor 124 having a smaller capacity than that of the first compressor 120 or the second compressor 122 can be utilized, using the power generated by the refrigerant pressure reducing device 160. ) Can increase reliquefaction efficiency and reliquefaction amount at low cost.
본 실시예의 추가냉각기(134)는, 제5 실시예와 마찬가지로, 재순환라인(L5) 상의 추가압축기(124) 하류에 설치되어, 추가압축기(124)에 의해 압축되며 압력뿐만 아니라 온도도 높아진 증발가스의 온도를 낮춘다.The additional cooler 134 of this embodiment, like the fifth embodiment, is installed downstream of the additional compressor 124 on the recirculation line L5, and is compressed by the additional compressor 124, and the pressure as well as the temperature is increased. Lower the temperature.
본 실시예는, 제5 실시예와 마찬가지로, 추가압축기(124)와 추가냉각기(134)를 재순환라인(L5) 상에 설치하여, 제2 열교환기(140)에서 냉매로 사용되는 유체가, 제4 실시예의 폐루프 냉매 사이클과 동일한 경로를 순환할 수 있도록 하면서도, 제1 압축기(120) 또는 제1 냉각기(130)가 고장난 경우, 제4 실시예보다 용이하게 제2 압축기(122) 및 제2 냉각기(132)를 통과한 증발가스를 연료수요처(180)에 연료로 공급할 수 있다. 또한, 후술하는 바와 같이, 제2 압축기(122)에 의해 압축된 증발가스를 연료수요처(180)에 공급하도록 시스템을 운용하던 도중, 제2 압축기(122) 또는 제2 냉각기(132)가 고장난 경우, 제4 실시예보다 용이하게 제1 압축기(120) 및 제1 냉각기(130)를 통과한 증발가스를 연료수요처(180)에 연료로 공급할 수 있다.In the present embodiment, as in the fifth embodiment, the additional compressor 124 and the additional cooler 134 are installed on the recirculation line L5 so that the fluid used as the refrigerant in the second heat exchanger 140 is formed. While allowing the first compressor 120 or the first cooler 130 to fail while circulating the same path as the closed loop refrigerant cycle of the fourth embodiment, the second compressor 122 and the second compressor are easier than the fourth embodiment. The boil-off gas passing through the cooler 132 may be supplied as fuel to the fuel demand unit 180. In addition, as described below, when the second compressor 122 or the second cooler 132 fails while the system is operated to supply the boil-off gas compressed by the second compressor 122 to the fuel demand 180. In addition, the boil-off gas passed through the first compressor 120 and the first cooler 130 may be supplied as fuel to the fuel demand unit 180 more easily than the fourth embodiment.
본 실시예의 제1 감압장치(150)는, 제5 실시예와 마찬가지로, 복귀라인(L3) 상에 설치되어, 제1 열교환기(110) 및 제2 열교환기(140)에 의해 냉각된 증발가스를 팽창시킨다. 본 실시예의 제1 감압장치(150)는, 증발가스를 팽창시켜 냉각시킬 수 있는 모든 수단을 포함하며, 줄-톰슨(Joule-Thomson) 밸브 등의 팽창밸브, 또는 팽창기일 수 있다.As in the fifth embodiment, the first pressure reducing device 150 of the present embodiment is installed on the return line L3 and is the boil-off gas cooled by the first heat exchanger 110 and the second heat exchanger 140. Inflate. The first pressure reducing device 150 of the present embodiment includes all means capable of expanding and cooling the boil-off gas, and may be an expansion valve such as a Joule-Thomson valve or an expander.
본 실시예의 선박은, 제5 실시예와 마찬가지로, 제1 감압장치(150) 하류의 복귀라인(L3) 상에 설치되며 제1 감압장치(150)으로부터 배출되는 기액 혼합물을 기체와 액체로 분리하는, 기액분리기(170)를 포함할 수 있다.The vessel of this embodiment, like the fifth embodiment, is installed on the return line L3 downstream of the first pressure reducing device 150 and separates the gas-liquid mixture discharged from the first pressure reducing device 150 into gas and liquid. , Gas-liquid separator 170 may be included.
제5 실시예와 마찬가지로, 본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는 제1 감압장치(150)를 통과한 액체 또는 기액혼합 상태의 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는 제1 감압장치(150)를 통과한 증발가스는 기액분리기(170)로 보내져, 기체상과 액체상이 분리된다. 기액분리기(170)에 의해 분리된 액체는 복귀라인(L3)을 따라 저장탱크(T)로 복귀하고, 기액분리기(170)에 의해 분리된 기체는, 기액분리기(170)로부터 제1 열교환기(110) 상류의 제1 공급라인(L1)까지 연장되는 기체배출라인(L4)을 따라, 제1 열교환기(110)으로 공급된다.As in the fifth embodiment, when the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or gaseous-mixed evaporated gas that has passed through the first pressure reducing device 150 is directly sent to the storage tank T. When the vessel of the present embodiment includes the gas-liquid separator 170, the boil-off gas passing through the first pressure reducing device 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3, and the gas separated by the gas-liquid separator 170 passes from the gas-liquid separator 170 to the first heat exchanger ( The gas is supplied to the first heat exchanger 110 along the gas discharge line L4 extending upstream of the first supply line L1.
본 실시예의 선박이 기액분리기(170)를 포함하는 경우, 제5 실시예와 마찬가지로, 기액분리기(170)에 의해 분리되어 저장탱크(T)로 보내지는 액체의 유량을 조절하는 제7 밸브(197); 및 기액분리기(170)에 의해 분리되어 제1 열교환기(110)로 보내지는 기체의 유량을 조절하는 제8 밸브(198);를 더 포함할 수 있다.When the ship of the present embodiment includes the gas-liquid separator 170, like the fifth embodiment, the seventh valve (197) for controlling the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank (T) ); And an eighth valve 198 that controls the flow rate of the gas separated by the gas-liquid separator 170 and sent to the first heat exchanger 110.
또한, 본 실시예의 선박은, 제5 실시예와 마찬가지로, 제1 추가라인(L6)을 포함하지 않고, 제1 공급라인(L1)으로부터 분기한 제2 공급라인(L2)이 제1 공급라인(L1)과 다시 합류되며, 재순환라인(L5)이, 제2 냉각기(132)와 제4 밸브(194) 사이의 제2 공급라인(L2)으로부터 분기된 후, 제3 밸브(193)와 제2 압축기(122) 사이의 제2 공급라인(L2)과 다시 합류된다.In addition, the ship of the present embodiment, like the fifth embodiment, does not include the first additional line L6, and the second supply line L2 branched from the first supply line L1 is the first supply line ( L1) is joined again, and after the recirculation line L5 branches from the second supply line L2 between the second cooler 132 and the fourth valve 194, the third valve 193 and the second It is again joined with the second supply line L2 between the compressors 122.
단, 본 실시예의 선박은, 제5 실시예와는 달리, 제2 추가라인(L11); 제2 추가라인(L11) 상에 설치되는 제13 밸브(206); 제3 추가라인(L12); 제3 추가라인(L12) 상에 설치되는 제14 밸브(207); 제4 추가라인(L13); 및 제4 추가라인(L13) 상에 설치되는 제15 밸브(208);를 포함한다.However, the ship of this embodiment, unlike the fifth embodiment, the second additional line (L11); A thirteenth valve 206 installed on the second additional line L11; Third additional line L12; A fourteenth valve 207 installed on the third additional line L12; A fourth additional line L13; And a fifteenth valve 208 installed on the fourth additional line L13.
본 실시예의 제2 추가라인(L11)은, 추가냉각기(134)와 제9 밸브(201) 사이의 재순환라인(L5)으로부터 분기되어 제1 밸브(191)와 제1 압축기(120) 사이의 제1 공급라인(L1)으로 합류된다.The second additional line L11 of the present embodiment is branched from the recirculation line L5 between the additional cooler 134 and the ninth valve 201 and is formed between the first valve 191 and the first compressor 120. 1 is joined to the supply line (L1).
본 실시예의 제3 추가라인(L12)은, 제1 냉각기(130)와 제2 밸브(192) 사이의 제1 공급라인(L1)으로부터 분기되어 제12 밸브(205)와 제2 열교환기(140) 사이의 재순환라인(L5)으로 합류된다.The third additional line L12 of the present embodiment is branched from the first supply line L1 between the first cooler 130 and the second valve 192 to be the twelfth valve 205 and the second heat exchanger 140. Is joined to the recirculation line L5.
본 실시예의 제4 추가라인(L13)은, 제2 냉각기(132)와 제4 밸브(194) 사이의 제2 공급라인(L2)으로부터 분기되어 제5 밸브(195)와 추진압축기(126) 사이의 복귀라인(L3)으로 합류된다.The fourth additional line L13 of the present embodiment branches from the second supply line L2 between the second cooler 132 and the fourth valve 194 to between the fifth valve 195 and the propulsion compressor 126. Is joined to the return line L3.
본 실시예에 의하면, 제5 실시예와는 달리, 제1 압축기(120)와 제2 압축기(122)를 모두, 냉매 사이클에 공급되는 증발가스를 압축시키는 용도; 또는 연료수요처(180)에 공급되는 증발가스를 압축시키는 용도;로 선택하여 사용할 수 있다. 또한, 본 실시예에 의하면, 제5 실시예와는 달리, 제1 공급라인(L1)으로부터 분기되는 증발가스뿐만 아니라, 제2 공급라인(L2)으로부터 분기되는 증발가스도 선택적으로 복귀라인(L3)을 따라 재액화 과정을 거치도록 할 수 있다.According to this embodiment, unlike the fifth embodiment, both the first compressor 120 and the second compressor 122, the use of compressing the boil-off gas supplied to the refrigerant cycle; Or it can be used to select; for the purpose of compressing the boil-off gas supplied to the fuel demand (180). Further, according to the present embodiment, unlike the fifth embodiment, not only the boil-off gas branched from the first supply line L1 but also the boil-off gas branched from the second supply line L2 is selectively returned to the line L3. ) Can be followed by a reliquefaction process.
즉, 제5 실시예에 의하면, 평상시 제1 압축기(120)에 의해 압축된 증발가스는 연료수요처(180)로 보내지거나 복귀라인(L3)을 따라 재액화 과정을 거치고, 제2 압축기(122)에 의해 압축된 증발가스는 냉매 사이클을 순환시키며, 제1 압축기(120)와 제2 압축기(122)의 용도를 바꾸어 사용할 수는 없었다.That is, according to the fifth embodiment, the boil-off gas which is normally compressed by the first compressor 120 is sent to the fuel demand 180 or undergoes a reliquefaction process along the return line L3, and the second compressor 122 The compressed boil-off gas circulates through the refrigerant cycle, and the use of the first compressor 120 and the second compressor 122 cannot be changed.
반면, 본 실시예에 의하면, 제1 압축기(120) 및 제2 압축기(122) 중 어느 하나를 선택하여 연료수요처(180)나 복귀라인(L3)으로 증발가스를 공급하도록 하고, 연료수요처(180)로 증발가스를 공급하지 않는 다른 압축기에 의해 압축된 증발가스로 냉매 사이클을 순환시킬 수 있다. 따라서, 본 실시예에 의하면, 제5 실시예에 비해 시스템의 운용이 자유롭다는 장점이 있다.On the other hand, according to the present embodiment, one of the first compressor 120 and the second compressor 122 is selected to supply the boil-off gas to the fuel demand 180 or the return line L3, and the fuel demand 180 The refrigerant cycle can be circulated with the boil-off gas compressed by another compressor which does not supply boil-off gas to Therefore, according to this embodiment, there is an advantage that the operation of the system is free compared with the fifth embodiment.
본 실시예의 제1 내지 제5 밸브(195), 제7 내지 제9 밸브, 제11 밸브 내지 제15 밸브(191, 192, 193, 194, 195, 197, 198, 201, 203, 205, 206, 207, 208)는, 시스템 운용 상황을 사람이 직접 판단하여 수동으로 조절될 수도 있고, 미리 설정된 값에 의해 개폐되도록 자동으로 조절될 수도 있다.The first to fifth valves 195, the seventh to ninth valves, the eleventh to fifteenth valves 191, 192, 193, 194, 195, 197, 198, 201, 203, 205, and 206 of the present embodiment. 207 and 208 may be manually adjusted by a person directly determining a system operating situation, or may be automatically adjusted to open and close by a preset value.
본 실시예의 냉매 사이클은 폐루프로 운용되는 것이 바람직하며, 이하, 밸브 조절을 통해 본 실시예의 냉매 사이클을 폐루프로 운용하는 방법을 설명한다.The refrigerant cycle of the present embodiment is preferably operated in a closed loop, hereinafter, a method of operating the refrigerant cycle of the present embodiment in a closed loop by adjusting a valve will be described.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하고, 제1 압축기(120)에 의해 압축된 증발가스를 연료수요처(180)로 보내고, 제2 압축기(122)에 의해 압축된 증발가스로 냉매 사이클을 순환시키기 위해서, 일단, 제1 밸브(191), 제2 밸브(192), 제3 밸브(193), 제4 밸브(194), 제5 밸브(195), 제9 밸브(201), 및 제12 밸브(205)는 열고, 제13 밸브(206), 제14 밸브(207), 및 제15 밸브(208)는 닫은 상태에서 시스템을 구동시킨다.The refrigerant cycle of the ship of the present embodiment is operated as a closed loop, and the evaporated gas compressed by the first compressor 120 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122. To circulate, the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the fifth valve 195, the ninth valve 201, and The twelfth valve 205 is opened, and the thirteenth valve 206, the fourteenth valve 207, and the fifteenth valve 208 drive the system in the closed state.
저장탱크(T)로부터 배출된 후 제2 압축기(122)에 의해 압축된 증발가스가 재순환라인(L5)으로 공급되면, 제3 밸브(193) 및 제4 밸브(194)를 닫아, 증발가스가 제2 압축기(122), 제2 냉각기(132), 제12 밸브(205), 제2 열교환기(140), 냉매감압장치(160), 다시 제2 열교환기(140), 추가압축기(124), 추가냉각기(134), 및 제9 밸브(201)를 순환하는, 폐루프의 냉매 사이클을 형성시킨다.When the boil-off gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recirculation line L5, the third valve 193 and the fourth valve 194 are closed to produce the boil-off gas. Second compressor 122, second cooler 132, twelfth valve 205, second heat exchanger 140, refrigerant pressure reducing device 160, second heat exchanger 140, and additional compressor 124. And a closed loop refrigerant cycle circulating through the additional cooler 134 and the ninth valve 201.
냉매 사이클을 폐루프로 구성하는 경우에는, 질소가스를 폐루프를 순환하는 냉매로 사용할 수도 있다. 이 경우, 본 실시예의 저장탱크(T)를 포함하는 저장탱크(T)는, 질소가스를 폐루프의 냉매 사이클 내로 도입시키는 배관을 더 포함할 수 있다.When the refrigerant cycle is configured as a closed loop, nitrogen gas may be used as the refrigerant circulating in the closed loop. In this case, the storage tank T including the storage tank T of the present embodiment may further include a pipe for introducing nitrogen gas into the refrigerant cycle of the closed loop.
냉매 사이클이 폐루프로 운용되는 경우, 폐루프를 순환하는 증발가스만이 제2 열교환기(140)에서의 냉매로 사용되며, 제1 압축기(120)를 통과한 증발가스는 냉매 사이클로 도입되지 못하고 연료수요처(180)로 공급되거나, 복귀라인(L3)을 따라 재액화 과정을 거치게 된다. 따라서, 재액화량이나, 연료수요처(180)에서 요구하는 증발가스량에 무관하게 일정한 유량의 증발가스가 제2 열교환기(140)의 냉매로 순환된다.When the refrigerant cycle is operated as a closed loop, only the boil-off gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the boil-off gas passing through the first compressor 120 cannot be introduced into the refrigerant cycle. It is supplied to the fuel demand 180, or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction or the amount of boil-off gas required by the fuel demand unit 180, the boil-off gas of a constant flow rate is circulated to the refrigerant of the second heat exchanger 140.
본 실시예의 냉매 사이클이 폐루프로 운용되는 경우, 개루프 또는 독립 개루프로 운용되는 경우에 비해, 재액화 과정을 거치는 증발가스와 냉매로 사용되는 증발가스 각각의 유량을 제어하기가 용이하다는 장점이 있다.When the refrigerant cycle of the present embodiment is operated in a closed loop, it is easier to control the flow rate of each of the evaporated gas that is undergoing the reliquefaction process and the evaporated gas used as the refrigerant compared to the case of operating the closed loop or the independent open loop. There is this.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하고, 제1 압축기(120)에 의해 압축된 증발가스를 연료수요처(180)로 보내고, 제2 압축기(122)에 의해 압축된 증발가스로 냉매 사이클을 순환시키는 경우, 증발가스의 흐름을 설명하면 다음과 같다.The refrigerant cycle of the ship of the present embodiment is operated as a closed loop, and the evaporated gas compressed by the first compressor 120 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122. When circulating, the flow of the boil-off gas will be described.
저장탱크(T)로부터 배출된 증발가스는 제1 열교환기(110)를 통과한 후 제1 압축기(120)에 의해 압축되고 제1 냉각기(130)에 의해 냉각된 후 일부는 연료수요처(180)로 보내지고, 나머지 일부는 복귀라인(L3)을 따라 재액화 과정을 거치게 된다.The boil-off gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, and a part of the fuel demand unit 180 is removed. The remaining part is subjected to the reliquefaction process along the return line (L3).
저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스는 대략 1 bar 일 수 있고, 대략 1 bar의 증발가스는 제1 압축기(120)에 의해 압축되어 대략 17 bar가 될 수 있다. 제1 압축기(120)에 의해 압축된 증발가스의 압력은, 시스템이 요구하는 재액화 성능 및 시스템의 운용 상황에 따라 달라질 수 있다.The evaporated gas passed through the first heat exchanger 110 after being discharged from the storage tank T may be about 1 bar, and about 1 bar of the evaporated gas may be compressed by the first compressor 120 so that approximately 17 bar may be Can be. The pressure of the boil-off gas compressed by the first compressor 120 may vary depending on the reliquefaction performance required by the system and the operating situation of the system.
복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스는, 추진압축기(126)에 의해 압축되고 추진냉각기(136)에 의해 냉각된 후, 제1 열교환기(110)에 의해 저장탱크(T)로부터 배출된 증발가스와 열교환되어 냉각된다. 제1 열교환기(110)에 의해 냉각된 증발가스는, 제2 열교환기(140)에서 열교환되어 추가적으로 냉각된 후 제1 감압장치(150)에 의해 팽창되어 일부 또는 전부가 재액화된다.The boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled. The boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는, 일부 또는 전부 재액화된 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는, 일부 또는 전부 재액화된 증발가스는 기액분리기(170)로 보내진다. 기액분리기(170)에 의해 분리된 기체는, 저장탱크(T)로부터 배출되는 증발가스와 합류되어 제1 열교환기(110)로 보내지고, 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 보내진다.When the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
한편, 냉매 사이클을 순환하는 증발가스는, 추가압축기(124)에 의해 압축되고 추가냉각기(134)에 의해 냉각된 후, 제2 압축기(122)에 의해 추가적으로 압축되고 제2 냉각기(132)에 의해 냉각되어, 재순환라인(L5)을 따라 제2 열교환기(140)로 보내진다. 추가압축기(124) 및 제2 압축기(122)를 통과한 후 제2 열교환기(140)로 보내진 증발가스는, 제2 열교환기(140)에서 1차로 열교환되어 냉각된 후 냉매감압장치(160)로 보내져 2차로 팽창되어 냉각된다.On the other hand, the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the second compressor 122 and by the second cooler 132. Cooled and sent to the second heat exchanger 140 along the recycle line (L5). After passing through the additional compressor 124 and the second compressor 122, the boil-off gas sent to the second heat exchanger 140 is first heat-exchanged by the second heat exchanger 140, and then cooled. It is sent to the secondary expansion and cooled.
추가압축기(124)에 의해 압축된 증발가스는 대략 2 bar일 수 있고, 대략 2 bar의 증발가스는 제2 압축기(122)에 의해 압축되어 대략 32 bar가 될 수 있다. 추가압축기(124)에 의해 압축된 증발가스의 압력 및 제2 압축기(122)에 의해 압축된 증발가스의 압력은, 시스템이 요구하는 재액화 성능 및 시스템의 운용 상황에 따라 달라질 수 있다.The boil-off gas compressed by the additional compressor 124 may be about 2 bar, and the boil-off gas of about 2 bar may be compressed by the second compressor 122 to be about 32 bar. The pressure of the boil-off gas compressed by the additional compressor 124 and the pressure of the boil-off gas compressed by the second compressor 122 may vary depending on the reliquefaction performance required by the system and the operating conditions of the system.
냉매감압장치(160)를 통과한 증발가스는 다시 제2 열교환기(140)로 보내져, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급된 증발가스; 및 추가압축기(124)와 제2 압축기(122)에 의해 압축된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 공급된 증발가스;를 냉각시키는 냉매로 사용된다. 냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 냉매로 사용된 증발가스는, 다시 추가압축기(124)로 보내져 상술한 일련의 과정을 반복한다.The evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하고, 제1 압축기(120)에 의해 압축된 증발가스를 연료수요처(180)로 보내고, 제2 압축기(122)에 의해 압축된 증발가스로 냉매 사이클을 순환시키는 도중, 제1 압축기(120) 또는 제1 냉각기(130)가 고장나게 되면, 제1 밸브(191), 제2 밸브(192), 제5 밸브(195), 제9 밸브(201), 및 제12 밸브(205)는 닫고, 제3 밸브(193) 및 제4 밸브(194)는 열어, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스가, 제3 밸브(193), 제2 압축기(122), 제2 냉각기(132), 및 제4 밸브(194)를 거쳐 연료수요처(180)로 공급되도록 한다.The refrigerant cycle of the ship of the present embodiment is operated as a closed loop, and the evaporated gas compressed by the first compressor 120 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122. If the first compressor 120 or the first cooler 130 breaks down while circulating, the first valve 191, the second valve 192, the fifth valve 195, and the ninth valve 201 are damaged. And the twelfth valve 205 is closed, the third valve 193 and the fourth valve 194 are opened, and the boil-off gas passed through the first heat exchanger 110 after being discharged from the storage tank T, The third valve 193, the second compressor 122, the second cooler 132, and the fourth valve 194 may be supplied to the fuel demand 180.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하고, 제2 압축기(122)에 의해 압축된 증발가스를 연료수요처(180)로 보내고, 제1 압축기(120)에 의해 압축된 증발가스로 냉매 사이클을 순환시키기 위해서, 일단, 제1 밸브(191), 제2 밸브(192), 제3 밸브(193), 제4 밸브(194), 제13 밸브(206), 제14 밸브(207), 및 제15 밸브(208)는 열고, 제5 밸브(195), 제9 밸브(201), 및 제12 밸브(205)는 닫은 상태에서 시스템을 구동시킨다.The refrigerant cycle of the ship of this embodiment is operated in a closed loop, and the evaporated gas compressed by the second compressor 122 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the boiled gas compressed by the first compressor 120. To circulate, the first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the thirteenth valve 206, the fourteenth valve 207, and The fifteenth valve 208 is opened, and the fifth valve 195, the ninth valve 201, and the twelfth valve 205 drive the system in a closed state.
저장탱크(T)로부터 배출된 후 제1 압축기(120)에 의해 압축된 증발가스가, 제3 추가라인(L12)을 따라 재순환라인(L5)으로 공급되면, 제1 밸브(191) 및 제2 밸브(192)를 닫아, 증발가스가 제1 압축기(120), 제1 냉각기(130), 제14 밸브(207), 제2 열교환기(140), 냉매감압장치(160), 다시 제2 열교환기(140), 추가압축기(124), 추가냉각기(134), 및 제13 밸브(206)를 순환하는, 폐루프의 냉매 사이클을 형성시킨다.When the boil-off gas compressed by the first compressor 120 after being discharged from the storage tank T is supplied to the recirculation line L5 along the third additional line L12, the first valve 191 and the second By closing the valve 192, the boil-off gas is discharged into the first compressor 120, the first cooler 130, the fourteenth valve 207, the second heat exchanger 140, the refrigerant pressure reducing device 160, and the second heat exchanger. A closed loop refrigerant cycle is formed that circulates the air 140, the additional compressor 124, the additional cooler 134, and the thirteenth valve 206.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하고, 제2 압축기(122)에 의해 압축된 증발가스를 연료수요처(180)로 보내고, 제1 압축기(120)에 의해 압축된 증발가스로 냉매 사이클을 순환시키는 경우, 증발가스의 흐름을 설명하면 다음과 같다.The refrigerant cycle of the ship of this embodiment is operated in a closed loop, and the evaporated gas compressed by the second compressor 122 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the boiled gas compressed by the first compressor 120. When circulating, the flow of the boil-off gas will be described.
저장탱크(T)로부터 배출된 증발가스는 제1 열교환기(110)를 통과한 후 제2 압축기(122)에 의해 압축되고 제2 냉각기(132)에 의해 냉각된 후 일부는 연료수요처(180)로 보내지고, 나머지 일부는 제15 밸브(208)를 지나 복귀라인(L3)을 따라 재액화 과정을 거치게 된다.The boil-off gas discharged from the storage tank T passes through the first heat exchanger 110, is compressed by the second compressor 122, and is cooled by the second cooler 132, and a part of the fuel demand 180 is removed. And the remaining part is passed through the fifteenth valve 208 to the reliquefaction process along the return line (L3).
저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스는 대략 1 bar 일 수 있고, 대략 1 bar의 증발가스는 제2 압축기(122)에 의해 압축되어 대략 17 bar가 될 수 있다. 제2 압축기(122)에 의해 압축된 증발가스의 압력은, 시스템이 요구하는 재액화 성능 및 시스템의 운용 상황에 따라 달라질 수 있다.The evaporated gas passed from the storage tank T and passed through the first heat exchanger 110 may be about 1 bar, and about 1 bar of the boil-off gas may be compressed by the second compressor 122 so that approximately 17 bar Can be. The pressure of the boil-off gas compressed by the second compressor 122 may vary depending on the reliquefaction performance required by the system and the operating situation of the system.
복귀라인(L3)을 따라 재액화 과정을 거치는 증발가스는, 추진압축기(126)에 의해 압축되고 추진냉각기(136)에 의해 냉각된 후, 제1 열교환기(110)에 의해 저장탱크(T)로부터 배출된 증발가스와 열교환되어 냉각된다. 제1 열교환기(110)에 의해 냉각된 증발가스는, 제2 열교환기(140)에서 열교환되어 추가적으로 냉각된 후 제1 감압장치(150)에 의해 팽창되어 일부 또는 전부가 재액화된다.The boil-off gas undergoing the reliquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then stored by the first heat exchanger 110 by the storage tank T. It is exchanged with the boil-off gas discharged from and cooled. The boil-off gas cooled by the first heat exchanger 110 is heat-exchanged in the second heat exchanger 140 and further cooled, and is then expanded by the first pressure reducing device 150 to re-liquefy some or all.
본 실시예의 선박이 기액분리기(170)를 포함하지 않는 경우에는, 일부 또는 전부 재액화된 증발가스는 바로 저장탱크(T)로 보내지고, 본 실시예의 선박이 기액분리기(170)를 포함하는 경우에는, 일부 또는 전부 재액화된 증발가스는 기액분리기(170)로 보내진다. 기액분리기(170)에 의해 분리된 기체는, 저장탱크(T)로부터 배출되는 증발가스와 합류되어 제1 열교환기(110)로 보내지고, 기액분리기(170)에 의해 분리된 액체는 저장탱크(T)로 보내진다.When the vessel of this embodiment does not include the gas-liquid separator 170, some or all of the re-liquefied boil-off gas is sent directly to the storage tank (T), when the vessel of this embodiment includes the gas-liquid separator 170 Partially or wholly reliquefied boil-off gas is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110, and the liquid separated by the gas-liquid separator 170 is stored in the storage tank ( Sent to T).
한편, 냉매 사이클을 순환하는 증발가스는, 추가압축기(124)에 의해 압축되고 추가냉각기(134)에 의해 냉각된 후, 제1 압축기(120)에 의해 추가적으로 압축되고 제1 냉각기(130)에 의해 냉각되어, 제14 밸브(207)를 지나 재순환라인(L5)을 따라 제2 열교환기(140)로 보내진다. 추가압축기(124) 및 제1 압축기(120)를 통과한 후 제2 열교환기(140)로 보내진 증발가스는, 제2 열교환기(140)에서 1차로 열교환되어 냉각된 후 냉매감압장치(160)로 보내져 2차로 팽창되어 냉각된다.Meanwhile, the boil-off gas circulating through the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, and then further compressed by the first compressor 120 and by the first cooler 130. After cooling, the fourteenth valve 207 is sent to the second heat exchanger 140 along the recirculation line L5. After passing through the additional compressor 124 and the first compressor 120, the evaporated gas sent to the second heat exchanger 140 is first heat exchanged and cooled in the second heat exchanger 140, and then the refrigerant pressure reducing device 160 is applied. It is sent to the secondary expansion and cooled.
추가압축기(124)에 의해 압축된 증발가스는 대략 2 bar일 수 있고, 대략 2 bar의 증발가스는 제1 압축기(120)에 의해 압축되어 대략 32 bar가 될 수 있다. 추가압축기(124)에 의해 압축된 증발가스의 압력 및 제1 압축기(120)에 의해 압축된 증발가스의 압력은, 시스템이 요구하는 재액화 성능 및 시스템의 운용 상황에 따라 달라질 수 있다.The boil-off gas compressed by the additional compressor 124 may be about 2 bar, and the boil-off gas of about 2 bar may be compressed by the first compressor 120 to be about 32 bar. The pressure of the boil-off gas compressed by the additional compressor 124 and the pressure of the boil-off gas compressed by the first compressor 120 may vary depending on the reliquefaction performance required by the system and the operating conditions of the system.
냉매감압장치(160)를 통과한 증발가스는 다시 제2 열교환기(140)로 보내져, 제1 열교환기(110)를 통과한 후 복귀라인(L3)을 따라 제2 열교환기(140)로 공급된 증발가스; 및 추가압축기(124)와 제1 압축기(120)에 의해 압축된 후 재순환라인(L5)을 따라 제2 열교환기(140)로 공급된 증발가스;를 냉각시키는 냉매로 사용된다. 냉매감압장치(160)를 통과한 후 제2 열교환기(140)에서 냉매로 사용된 증발가스는, 다시 추가압축기(124)로 보내져 상술한 일련의 과정을 반복한다.The evaporated gas passing through the refrigerant pressure reducing device 160 is sent to the second heat exchanger 140 again, and passes through the first heat exchanger 110, and then is supplied to the second heat exchanger 140 along the return line L3. Evaporated gas; And a boil-off gas compressed by the additional compressor 124 and the first compressor 120 and then supplied to the second heat exchanger 140 along the recirculation line L5. After passing through the refrigerant pressure reducing device 160, the boil-off gas used as the refrigerant in the second heat exchanger 140 is sent to the additional compressor 124 again and repeats the above-described series of processes.
본 실시예의 선박의 냉매 사이클을 폐루프로 운용하고, 제2 압축기(122)에 의해 압축된 증발가스를 연료수요처(180)로 보내고, 제1 압축기(120)에 의해 압축된 증발가스로 냉매 사이클을 순환시키는 도중, 제2 압축기(122) 또는 제2 냉각기(132)가 고장나게 되면, 제3 밸브(193), 제4 밸브(194), 제13 밸브(206), 제14 밸브(207), 및 제15 밸브(208)는 닫고, 제1 밸브(191) 및 제2 밸브(192)는 열어, 저장탱크(T)로부터 배출된 후 제1 열교환기(110)를 통과한 증발가스가, 제1 밸브(191), 제1 압축기(120), 제1 냉각기(130), 및 제2 밸브(192)를 거쳐 연료수요처(180)로 공급되도록 한다.The refrigerant cycle of the ship of this embodiment is operated in a closed loop, and the evaporated gas compressed by the second compressor 122 is sent to the fuel demand unit 180, and the refrigerant cycle is compressed by the boiled gas compressed by the first compressor 120. If the second compressor 122 or the second cooler 132 fails during the circulation, the third valve 193, the fourth valve 194, the thirteenth valve 206, and the fourteenth valve 207 are damaged. , And the fifteenth valve 208 is closed, the first valve 191 and the second valve 192 are opened, and the evaporated gas passed through the first heat exchanger 110 after being discharged from the storage tank T, The first valve 191, the first compressor 120, the first cooler 130, and the second valve 192 are supplied to the fuel demand 180.
본 발명은 상기 실시예에 한정되지 않고, 본 발명의 기술적 요지를 벗어나지 아니하는 범위 내에서 다양하게 수정 또는 변형되어 실시될 수 있음은 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에 있어서 자명한 것이다.The present invention is not limited to the above embodiments, and various modifications or changes may be made without departing from the technical spirit of the present invention, which will be apparent to those of ordinary skill in the art. It is.

Claims (22)

  1. 액화가스 저장탱크를 포함하는 선박에 있어서,In a ship comprising a liquefied gas storage tank,
    상기 저장탱크로부터 배출되는 증발가스의 적어도 일부를 압축시킬 수 있는 제1 압축기;A first compressor capable of compressing at least a portion of the boil-off gas discharged from the storage tank;
    상기 저장탱크로부터 배출되는 증발가스의 다른 일부를 압축시키는 제2 압축기;A second compressor for compressing another part of the boil-off gas discharged from the storage tank;
    상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 일부를 압축시키는 추진압축기;A propelling compressor for compressing a part of the boil-off gas compressed by at least one of the first compressor and the second compressor;
    상기 추진압축기에 의해 압축된 증발가스와 상기 저장탱크로부터 배출되는 증발가스를 열교환시키는 제1 열교환기;A first heat exchanger configured to heat exchange the boil-off gas compressed by the propulsion compressor with the boil-off gas discharged from the storage tank;
    상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 다른 일부를 팽창시키는 냉매감압장치;A refrigerant reducing device for expanding another part of the boil-off gas compressed by at least one of the first compressor and the second compressor;
    상기 냉매감압장치에 의해 팽창된 유체를 냉매로하여 상기 추진압축기에 의해 압축되고 상기 제1 열교환기에서 열교환된 증발가스를 냉각시키는 제2 열교환기;A second heat exchanger configured to cool the boil-off gas compressed by the propulsion compressor and heat-exchanged in the first heat exchanger by using the fluid expanded by the refrigerant reduction device as a refrigerant;
    상기 냉매감압장치 및 상기 제2 열교환기를 통과한 냉매를 압축시키는 추가압축기; 및An additional compressor for compressing the refrigerant having passed through the refrigerant reducing device and the second heat exchanger; And
    상기 추진압축기에 의해 압축된 후 상기 제1 열교환기 및 상기 제2 열교환기에서 냉각된 유체를 팽창시키는 제1 감압장치;를 포함하고,And a first pressure reducing device that expands the fluid cooled in the first heat exchanger and the second heat exchanger after being compressed by the propulsion compressor.
    상기 추가압축기는 상기 냉매감압장치가 유체를 팽창시키면서 생산하는 동력에 의해 구동되는, 선박.The additional compressor is driven by the power that the refrigerant reducing device produces while expanding the fluid.
  2. 청구항 1에 있어서,The method according to claim 1,
    상기 추진압축기는 상기 제1 압축기에 의해 압축된 증발가스만을 압축시키되,The propulsion compressor compresses only the boil-off gas compressed by the first compressor,
    상기 냉매감압장치는 상기 제2 압축기에 의해 압축된 증발가스만을 팽창시키는 것을 특징으로 하는, 선박.The refrigerant reduction device is characterized in that for expanding only the boil-off gas compressed by the second compressor, the ship.
  3. 청구항 2에 있어서,The method according to claim 2,
    상기 추가압축기는 상기 제2 열교환기를 통과한 냉매를 압축하여 상기 제2 압축기로 보내는 것을 특징으로 하는, 선박.And the additional compressor compresses the refrigerant passing through the second heat exchanger and sends the refrigerant to the second compressor.
  4. 청구항 2에 있어서,The method according to claim 2,
    상기 추가압축기는 상기 제2 열교환기를 통과한 냉매를 압축하여 상기 제1 압축기 및 상기 제2 압축기로 보내는 것을 특징으로 하는, 선박.And the additional compressor compresses the refrigerant passing through the second heat exchanger and sends the refrigerant to the first compressor and the second compressor.
  5. 청구항 1에 있어서,The method according to claim 1,
    상기 추진압축기는 상기 제1 압축기와 상기 제2 압축기에 의해 압축된 증발가스 중 일부를 압축시키고,The propulsion compressor compresses a part of the boil-off gas compressed by the first compressor and the second compressor,
    상기 냉매감압장치는 상기 제1 압축기와 상기 제2 압축기에 의해 압축된 증발가스 중 다른 일부를 팽창시키는 것을 특징으로 하는, 선박The refrigerant reducing device is characterized in that for expanding the other part of the boil-off gas compressed by the first compressor and the second compressor, the ship
  6. 청구항 1 내지 청구항 5 중 어느 한 항에 있어서,The method according to any one of claims 1 to 5,
    상기 제2 열교환기는, 상기 냉매감압장치에 의해 팽창된 냉매로 상기 냉매감압장치를 통과하기 전의 유체를 냉각시킬 수 있는 것을 특징으로 하는, 선박.And the second heat exchanger is capable of cooling the fluid before passing through the refrigerant pressure reduction device with the refrigerant expanded by the refrigerant pressure reduction device.
  7. 청구항 1 내지 청구항 5 중 어느 한 항에 있어서,The method according to any one of claims 1 to 5,
    상기 제1 감압장치를 통과한 유체에서 액화가스와 증발가스를 분리하는 기액분리기를 더 포함하고,Further comprising a gas-liquid separator for separating the liquefied gas and the evaporated gas from the fluid passing through the first decompression device,
    상기 기액분리기에서 분리된 액화가스는 상기 저장탱크로 보내지는, 선박.The liquefied gas separated in the gas-liquid separator is sent to the storage tank.
  8. 청구항 1 내지 청구항 5 중 어느 한 항에 있어서,The method according to any one of claims 1 to 5,
    상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 다른 일부는 연료수요처로 공급되는, 선박.And the other part of the boil-off gas compressed by at least one of the first compressor and the second compressor is supplied to the fuel demand.
  9. 청구항 3에 있어서,The method according to claim 3,
    상기 냉매는 적어도 상기 추가압축기, 상기 제2 압축기, 상기 냉매감압장치 및 상기 제2 열교환기를 순환하는 폐루프 냉매 사이클을 형성하는, 선박.Said refrigerant forming a closed loop refrigerant cycle circulating at least said further compressor, said second compressor, said refrigerant reducing device and said second heat exchanger.
  10. 액화가스 저장탱크를 포함하는 선박에 있어서,In a ship comprising a liquefied gas storage tank,
    상기 저장탱크로부터 배출되는 증발가스의 적어도 일부를 압축시킬 수 있는 제1 압축기;A first compressor capable of compressing at least a portion of the boil-off gas discharged from the storage tank;
    상기 저장탱크로부터 배출되는 증발가스의 다른 일부를 압축시키는 제2 압축기;A second compressor for compressing another part of the boil-off gas discharged from the storage tank;
    상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 일부를 압축시키는 추진압축기;A propelling compressor for compressing a part of the boil-off gas compressed by at least one of the first compressor and the second compressor;
    상기 제1 압축기 또는 상기 제2 압축기 중 적어도 어느 하나에 의해 압축된 증발가스 중 다른 일부를 팽창시키는 냉매감압장치;A refrigerant reducing device for expanding another part of the boil-off gas compressed by at least one of the first compressor and the second compressor;
    상기 냉매감압장치에 의해 팽창된 유체를 냉매로하여 상기 추진압축기에 의해 압축된 증발가스를 냉각시키는 제2 열교환기;A second heat exchanger configured to cool the boil-off gas compressed by the propulsion compressor using the fluid expanded by the refrigerant reduction device as a refrigerant;
    상기 냉매감압장치 및 상기 제2 열교환기를 통과한 냉매를 압축시키는 추가압축기; 및An additional compressor for compressing the refrigerant having passed through the refrigerant reducing device and the second heat exchanger; And
    상기 추진압축기에 의해 압축된 후 상기 제2 열교환기에서 냉각된 유체를 팽창시키는 제1 감압장치;를 포함하고,And a first pressure reducing device that expands the fluid cooled in the second heat exchanger after being compressed by the propulsion compressor.
    상기 추가압축기는 상기 냉매감압장치가 유체를 팽창시키면서 생산하는 동력에 의해 구동되는, 선박.The additional compressor is driven by the power that the refrigerant reducing device produces while expanding the fluid.
  11. 액화가스를 저장하는 저장탱크를 포함하는 선박의 증발가스 처리 시스템에 있어서,In the boil-off gas treatment system including a storage tank for storing liquefied gas,
    상기 저장탱크로부터 배출되는 증발가스의 일부를 제1 압축기에 의해 압축시킨 후 연료수요처로 보내는 제1 공급라인;A first supply line compressing a part of the boil-off gas discharged from the storage tank by a first compressor and then sending the fuel to a fuel demand;
    상기 제1 공급라인으로부터 분기되어, 상기 저장탱크로부터 배출되는 증발가스의 다른 일부를 제2 압축기에 의해 압축시키는 제2 공급라인;A second supply line branched from the first supply line and compressing another portion of the boil-off gas discharged from the storage tank by a second compressor;
    상기 제1 공급라인으로부터 분기되어, 압축된 증발가스를 추진압축기에 의해 추가적으로 압축시킨 후 제1 열교환기, 제2 열교환기, 및 제1 감압장치를 통과시켜 재액화시키는 복귀라인;A return line branched from the first supply line to further compress the compressed boil-off gas by means of a propulsion compressor and then reliquefy by passing through a first heat exchanger, a second heat exchanger, and a first pressure reducing device;
    상기 제2 열교환기 및 냉매감압장치를 통과하며 냉각된 증발가스를 다시 상기 제2 열교환기로 보내 냉매로 사용하도록 하는 재순환라인; 및A recirculation line passing through the second heat exchanger and the refrigerant pressure reducing device and sending the cooled boil-off gas back to the second heat exchanger for use as a refrigerant; And
    상기 제2 압축기 상류에 설치되어 증발가스를 압축시키는 추가압축기;를 포함하고,And an additional compressor installed upstream of the second compressor to compress the boil-off gas.
    상기 추가압축기는 상기 냉매감압장치가 유체를 팽창시키면서 생산하는 동력에 의해 구동되고,The additional compressor is driven by the power produced by the refrigerant reducing device to expand the fluid,
    상기 제1 열교환기는, 상기 저장탱크로부터 배출된 증발가스를 냉매로 하여, 상기 추진압축기에 의해 압축된 후 상기 복귀라인을 따라 공급되는 증발가스를 열교환시켜 냉각시키고,The first heat exchanger is a refrigerant by using the evaporated gas discharged from the storage tank as a refrigerant, and by cooling by heat-exchanging the evaporated gas supplied along the return line after being compressed by the propulsion compressor,
    상기 제2 열교환기는, 상기 냉매감압장치를 통과한 증발가스를 냉매로 하여, 상기 재순환라인을 따라 공급되는 증발가스; 및 상기 복귀라인을 따라 공급되는 증발가스;를 둘 다 열교환시켜 냉각시키는, 선박의 증발가스 처리 시스템.The second heat exchanger includes a boil-off gas supplied along the recirculation line using the boil-off gas passed through the refrigerant reducing device as a refrigerant; And boil-off gas supplied along the return line.
  12. 청구항 11에 있어서,The method according to claim 11,
    상기 추가압축기는 상기 제2 공급라인 상에 설치되는, 선박의 증발가스 처리 시스템.The additional compressor is installed on the second supply line, the boil-off gas treatment system.
  13. 청구항 11에 있어서,The method according to claim 11,
    상기 추가압축기는 상기 냉매감압장치 및 상기 제2 열교환기 하류의 상기 재순환라인 상에 설치되는, 선박의 증발가스 처리 시스템.And the additional compressor is installed on the recirculation line downstream of the refrigerant reducing device and the second heat exchanger.
  14. 청구항 12에 있어서,The method according to claim 12,
    상기 냉매감압장치 및 상기 제2 열교환기 하류의 재순환라인과, 상기 제2 압축기 상류의 제2 공급라인 사이를 연결하는 제1 추가라인을 포함하는, 선박의 증발가스 처리 시스템.And a first additional line connecting between the refrigerant reduction device and the recirculation line downstream of the second heat exchanger and a second supply line upstream of the second compressor.
  15. 청구항 14에 있어서,The method according to claim 14,
    증발가스가 상기 추가압축기, 상기 제2 압축기, 상기 제2 열교환기, 상기 냉매감압장치, 및 다시 상기 제2 열교환기를 통과한 후, 상기 제1 추가라인을 지나 다시 상기 추가압축기로 공급되는, 폐루프의 냉매 사이클을 형성하는, 선박의 증발가스 처리 시스템.The boil-off gas is passed through the first compressor, the second compressor, the second heat exchanger, the refrigerant pressure reducing device, and again the second heat exchanger, and then supplied through the first additional line to the additional compressor again. Evaporation gas treatment system of a ship, forming a refrigerant cycle of the loop.
  16. 청구항 14에 있어서,The method according to claim 14,
    상기 제1 압축기에 의해 압축된 증발가스와 상기 제2 압축기에 의해 압축된 증발가스가 합류되어,The boil-off gas compressed by the first compressor and the boil-off gas compressed by the second compressor are joined,
    일부는 상기 복귀라인을 따라 재액화되고,Part is liquefied along the return line,
    다른 일부는 상기 재순환라인을 따라 상기 제2 열교환기, 상기 냉매감압장치, 및 다시 상기 제2 열교환기를 통과한 후, 상기 저장탱크로부터 배출되어 상기 제1 열교환기를 통과한 유체와 합류되고,The other part is passed through the second heat exchanger, the refrigerant pressure reducing device, and again the second heat exchanger along the recirculation line, and then discharged from the storage tank and joined with the fluid passing through the first heat exchanger,
    나머지 일부는 상기 연료수요처로 공급되는, 선박의 증발가스 처리 시스템.And the remaining part is supplied to the fuel demand.
  17. 청구항 14에 있어서,The method according to claim 14,
    상기 제1 압축기에 의해 압축된 증발가스는, 일부는 상기 복귀라인을 따라 재액화되고, 나머지 일부는 상기 연료수요처로 공급되고,The boil-off gas compressed by the first compressor is partially reliquefied along the return line, and the other part is supplied to the fuel demand,
    상기 제2 압축기에 의해 압축된 증발가스는, 상기 재순환라인을 따라 상기 제2 열교환기, 상기 냉매감압장치, 및 다시 상기 제2 열교환기를 통과한 후, 상기 저장탱크로부터 배출되어 상기 제1 열교환기를 통과한 유체와 합류되는, 선박의 증발가스 처리 시스템.The boil-off gas compressed by the second compressor passes through the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger along the recirculation line, and then is discharged from the storage tank to discharge the first heat exchanger. An evaporative gas treatment system for a vessel that is joined with the fluid that has passed.
  18. 청구항 13에 있어서,The method according to claim 13,
    증발가스가 상기 제2 압축기, 상기 제2 열교환기, 상기 냉매감압장치, 다시 상기 제2 열교환기, 및 상기 추가압축기를 순환하는, 폐루프의 냉매 사이클을 형성하는, 선박의 증발가스 처리 시스템.A boil-off gas treatment system for a boil-off gas forming a closed loop refrigerant cycle circulating the second compressor, the second heat exchanger, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor.
  19. 청구항 13에 있어서,The method according to claim 13,
    상기 추가압축기 하류의 재순환라인으로부터 분기되어, 상기 제1 압축기 상류의 상기 제1 공급라인과 연결되는 제2 추가라인;A second additional line branching from a recirculation line downstream of the further compressor and connected to the first supply line upstream of the first compressor;
    상기 제1 압축기 하류의 제1 공급라인으로부터 분기되어, 상기 냉매감압장치 및 상기 제2 열교환기 상류의 재순환라인과 연결되는 제3 추가라인; 및A third additional line branched from a first supply line downstream of the first compressor and connected to a recirculation line upstream of the refrigerant reducing device and the second heat exchanger; And
    상기 제2 압축기 하류의 제2 공급라인으로부터 분기되어, 상기 추진압축기 상류의 상기 복귀라인과 연결되는 제4 추가라인;A fourth additional line branching from a second supply line downstream of the second compressor and connected to the return line upstream of the propulsion compressor;
    을 포함하는, 선박의 증발가스 처리 시스템.Including, the boil off gas treatment system.
  20. 청구항 19에 있어서,The method according to claim 19,
    증발가스가 상기 제2 압축기에 의해 압축된 후, 상기 재순환라인을 따라 상기 제2 열교환기, 상기 냉매감압장치, 다시 상기 제2 열교환기, 및 상기 추가압축기를 통과하여 다시 상기 제2 압축기로 다시 공급되는, 폐루프의 냉매 사이클을 형성하는, 선박의 증발가스 처리 시스템.After the boil-off gas is compressed by the second compressor, it passes through the second heat exchanger, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor along the recirculation line and back to the second compressor. A boil-off gas treatment system for supplying a closed loop refrigerant cycle to be supplied.
  21. 청구항 19에 있어서,The method according to claim 19,
    증발가스가 상기 제1 압축기에 의해 압축된 후, 상기 제3 추가라인 및 상기 재순환라인을 따라 상기 제2 열교환기로 공급되고, 상기 냉매감압장치, 다시 상기 제2 열교환기, 및 상기 추가압축기를 통과하여, 상기 제2 추가라인을 따라 상기 제1 압축기로 다시 공급되는, 폐루프의 냉매 사이클을 형성하는, 선박의 증발가스 처리 시스템.After the boil-off gas is compressed by the first compressor, it is supplied to the second heat exchanger along the third additional line and the recirculation line, and passes through the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor. Thereby forming a closed loop refrigerant cycle which is fed back to the first compressor along the second additional line.
  22. 액화가스 저장탱크로부터 배출되는 증발가스를 둘로 분기하여, 상기 분기된 증발가스 중 한 흐름은 제1 압축기에 의해 압축시키고, 다른 흐름은 제2 압축기에 의해 압축시키고,Distilling the boil-off gas discharged from the liquefied gas storage tank into two, one of the branched boil-off gas is compressed by the first compressor, the other is compressed by the second compressor,
    상기 제1 압축기에 의해 압축된 증발가스는 추진압축기에 의해 추가적으로 압축시킨 후에 재액화시켜 상기 저장탱크로 복귀시키고,The boil-off gas compressed by the first compressor is further compressed by a propulsion compressor and then re-liquefied to return to the storage tank,
    상기 제2 압축기에 의해 압축된 증발가스는 냉매 사이클을 순환시켜 상기 제1 압축기에 의해 압축된 증발가스를 냉각시키는 냉매로 사용하고,The evaporated gas compressed by the second compressor is used as a refrigerant for circulating a refrigerant cycle to cool the evaporated gas compressed by the first compressor,
    상기 냉매 사이클을 순환하는 유체는, 추가압축기에 의해 압축된 후 상기 제2 압축기로 공급되는, 방법.And the fluid circulating in the refrigerant cycle is supplied to the second compressor after being compressed by an additional compressor.
PCT/KR2016/005139 2015-06-02 2016-05-16 Ship WO2016195279A1 (en)

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US15/579,571 US10654553B2 (en) 2015-06-02 2016-05-16 Ship with boil-off gas liquefaction system
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