TW201925707A - BOG recondenser and LNG supply system provided with same - Google Patents
BOG recondenser and LNG supply system provided with same Download PDFInfo
- Publication number
- TW201925707A TW201925707A TW107119866A TW107119866A TW201925707A TW 201925707 A TW201925707 A TW 201925707A TW 107119866 A TW107119866 A TW 107119866A TW 107119866 A TW107119866 A TW 107119866A TW 201925707 A TW201925707 A TW 201925707A
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- Prior art keywords
- refrigerant
- gas
- condenser
- heat exchange
- liquefied natural
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- 239000003507 refrigerant Substances 0.000 claims description 210
- 239000007789 gas Substances 0.000 claims description 143
- 239000003949 liquefied natural gas Substances 0.000 claims description 111
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 101
- 239000007788 liquid Substances 0.000 claims description 47
- 229910052757 nitrogen Inorganic materials 0.000 claims description 47
- 238000001704 evaporation Methods 0.000 claims description 35
- 238000009833 condensation Methods 0.000 claims description 9
- 230000005494 condensation Effects 0.000 claims description 9
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 9
- 230000001105 regulatory effect Effects 0.000 claims description 6
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 44
- 238000001816 cooling Methods 0.000 abstract description 4
- 239000012535 impurity Substances 0.000 abstract description 4
- 239000002826 coolant Substances 0.000 abstract 2
- 230000008020 evaporation Effects 0.000 description 17
- 239000007791 liquid phase Substances 0.000 description 9
- 239000012071 phase Substances 0.000 description 7
- 238000007710 freezing Methods 0.000 description 4
- 230000008014 freezing Effects 0.000 description 4
- 238000007711 solidification Methods 0.000 description 4
- 230000008023 solidification Effects 0.000 description 4
- 238000012546 transfer Methods 0.000 description 3
- 239000003570 air Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003915 liquefied petroleum gas Substances 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000009835 boiling Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 238000007712 rapid solidification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Classifications
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- 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
- F25J1/0221—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 the cold stored in an external cryogenic component in an open refrigeration loop
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- 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
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/004—Details of vessels or of the filling or discharging of vessels for large storage vessels not under pressure
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- 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
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/02—Special adaptations of indicating, measuring, or monitoring equipment
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- 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
- F17C13/00—Details of vessels or of the filling or discharging of vessels
- F17C13/04—Arrangement or mounting of valves
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- 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
- F17C9/04—Recovery of thermal energy
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- 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
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- 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
- F25J1/0244—Operation; Control and regulation; Instrumentation
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- 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
- F25J1/0244—Operation; Control and regulation; Instrumentation
- F25J1/0256—Safety aspects of operation
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- 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
- F25J1/0258—Construction and layout of liquefaction equipments, e.g. valves, machines vertical layout of the equipments within in the cold box
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- 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
- F25J1/0262—Details of the cold heat exchange system
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- 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
- F17C2250/00—Accessories; Control means; Indicating, measuring or monitoring of parameters
- F17C2250/01—Intermediate tanks
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- 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
- F17C2260/00—Purposes of gas storage and gas handling
- F17C2260/03—Dealing with losses
- F17C2260/031—Dealing with losses due to heat transfer
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- 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
- F17C2265/00—Effects achieved by gas storage or gas handling
- F17C2265/03—Treating the boil-off
- F17C2265/032—Treating the boil-off by recovery
- F17C2265/033—Treating the boil-off by recovery with cooling
- F17C2265/034—Treating the boil-off by recovery with cooling with condensing the gas phase
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- 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
- F17C2270/00—Applications
- F17C2270/01—Applications for fluid transport or storage
- F17C2270/0102—Applications for fluid transport or storage on or in the water
- F17C2270/0105—Ships
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- 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
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/04—Mixing or blending of fluids with the feed stream
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- 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
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/40—Air or oxygen enriched air, i.e. generally less than 30mol% of O2
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- 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
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/42—Nitrogen
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- 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
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/62—Separating low boiling components, e.g. He, H2, N2, Air
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- 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
- F25J2245/00—Processes or apparatus involving steps for recycling of process streams
- F25J2245/42—Processes or apparatus involving steps for recycling of process streams the recycled stream being nitrogen
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- 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
- F25J2250/00—Details related to the use of reboiler-condensers
- F25J2250/02—Bath type boiler-condenser using thermo-siphon effect, e.g. with natural or forced circulation or pool boiling, i.e. core-in-kettle heat exchanger
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- 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
- F25J2250/00—Details related to the use of reboiler-condensers
- F25J2250/10—Boiler-condenser with superposed stages
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- 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
- F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
- F25J2290/62—Details of storing a fluid in a tank
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
Description
本發明係關於一種用以將液化天然氣之蒸發氣體再冷凝之蒸發氣體再冷凝裝置及具備其的液化天然氣供給系統。 The present invention relates to an evaporation gas recondensing device for recondensing an evaporated gas of liquefied natural gas and a liquefied natural gas supply system therewith.
於儲藏如液化天然氣(Liquefied Natural Gas,LNG)或液化石油氣(Liquefied Petroleum Gas,LPG)般之低溫液體之情形時，一般而言使用將藉由來自外部之自然熱輸入等而氣化後之蒸發氣體(Boil-off Gas,BOG)再次液化、冷凝之再冷凝裝置(亦稱為再冷凝器Recondenser)。 In the case of storing a cryogenic liquid such as Liquefied Natural Gas (LNG) or Liquefied Petroleum Gas (LPG), it is generally used after being vaporized by natural heat input from the outside or the like. A recondensing device (also known as a recondenser Recondenser) that liquefies and condenses the boil-off gas (BOG).
已知有如下方法：將自儲藏液化天然氣之儲槽產生之蒸發氣體藉由與如液態氮或液態空氣般之極低溫冷媒之熱交換而再冷凝之後，向液化天然氣緩衝槽返送(例如專利文獻1)。 There is known a method in which an evaporating gas generated from a storage tank for storing liquefied natural gas is recondensed by heat exchange with a cryogenic refrigerant such as liquid nitrogen or liquid air, and then returned to a liquefied natural gas buffer tank (for example, patent document) 1).
[先前技術文獻] [Previous Technical Literature]
[專利文獻] [Patent Literature]
[專利文獻1]日本特開2002-295799號公報 [Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-295799
於使液態氮為冷媒之蒸發氣體之再冷凝裝置中，通常液態氮與 自液化天然氣緩衝槽產生之蒸發氣體之熱交換係於單一之再冷凝器內進行。因此，存在如下問題：於再冷凝器內，於溫度相對較高之蒸發氣體與極低溫之液態氮之間會進行急遽之熱交換，作為蒸發氣體內之主成分之甲烷或雜質會凝固而使配管堵塞。 In a recondensing device that uses liquid nitrogen as a vaporizing gas for a refrigerant, usually liquid nitrogen and The heat exchange of the boil-off gas from the liquefied natural gas buffer tank is carried out in a single recondenser. Therefore, there is a problem in that in the recondenser, heat exchange between the vaporized gas having a relatively high temperature and the liquid nitrogen at a very low temperature is performed, and methane or impurities which are main components in the vaporized gas are solidified. The piping is clogged.
又，若將再冷凝器內之蒸發氣體過度冷卻則再冷凝器內會成為負壓，再冷凝器有變形或產生故障之虞。為了減少變形或故障，必須形成為強度較高之耐壓構造，但此種設計自構件之選定、構造之複雜度之觀點而言並不容易。 Further, if the evaporation gas in the recondenser is excessively cooled, the inside of the condenser becomes a negative pressure, and the condenser is deformed or malfunctions. In order to reduce deformation or failure, it is necessary to form a high-strength pressure-resistant structure, but such a design is not easy from the viewpoint of the selection of components and the complexity of construction.
鑒於上述實際情況，於本發明中，目的在於提供一種減少由作為主成分之甲烷或雜質所致之再冷凝裝置內之配管之堵塞的液化天然氣再冷凝裝置及液化天然氣再冷凝方法。 In view of the above circumstances, it is an object of the present invention to provide a liquefied natural gas recondensing device and a liquefied natural gas recondensing method for reducing clogging of piping in a recondensing device caused by methane or impurities as a main component.
(發明1) (Invention 1)
本發明之蒸發氣體再冷凝裝置係一種將自液化天然氣緩衝槽內之液化天然氣氣化後之蒸發氣體(BOG)再冷凝之蒸發氣體再冷凝裝置，且具備：蒸發氣體導出配管，其將蒸發氣體自液化天然氣緩衝槽導出；第一冷凝器，其使自上述蒸發氣體導出配管傳送之蒸發氣體冷卻至第一溫度；第一氣體供給部，其將上述第一冷凝器內之氣體自上述第一冷凝器導出；第一返送配管，其將上述第一冷凝器內之液化天然氣自上述第一冷凝器返送至上述液化天然氣緩衝槽；第二冷凝器，其將自上述第一氣體供給部傳送之蒸發氣體冷卻至較上述第一溫度低之第二溫度；及第二返送配管，其將上述第二冷凝器內之液化天然氣自上述第二冷凝器返 送至上述液化天然氣緩衝槽；且上述蒸發氣體再冷凝裝置進一步具備冷媒控制手段，該冷媒控制手段對向上述第一冷凝器傳送之第一冷媒及/或向上述第二冷凝器傳送之第二冷媒之送入量及/或溫度進行控制。 The evaporating gas recondensing device of the present invention is an evaporating gas recondensing device for recondensing boil-off gas (BOG) vaporized from liquefied natural gas in a liquefied natural gas buffer tank, and is provided with an evaporating gas discharge pipe which will evaporate gas Deriving from a liquefied natural gas buffer tank; a first condenser that cools the boil-off gas delivered from the evaporating gas outlet piping to a first temperature; and a first gas supply unit that supplies the gas in the first condenser from the first a first outlet pipe for returning the liquefied natural gas in the first condenser from the first condenser to the liquefied natural gas buffer tank; and a second condenser that is to be transferred from the first gas supply unit Cooling gas is cooled to a second temperature lower than the first temperature; and a second return pipe is configured to return the liquefied natural gas in the second condenser from the second condenser And the evaporating gas recondensing device further includes a refrigerant control means for transmitting the first refrigerant to the first condenser and/or the second to the second condenser The amount of refrigerant delivered and/or temperature is controlled.
液化天然氣之蒸發氣體主要包含甲烷與氮作為成分，為了甲烷之冷凝，例如需要如液態氮或液態空氣般之低溫冷媒。然而，該等冷媒會成為較甲烷之固化點低之溫度，故而直接將蒸發氣體導入至以液態氮或液態空氣為冷媒之第二冷凝器存在導致甲烷固化之可能性。 The evaporating gas of the liquefied natural gas mainly contains methane and nitrogen as components, and for the condensation of methane, for example, a low-temperature refrigerant such as liquid nitrogen or liquid air is required. However, these refrigerants may be at a lower temperature than the solidification point of methane, so that direct introduction of the boil-off gas into the second condenser in which liquid nitrogen or liquid air is used as a refrigerant causes the possibility of solidification of methane.
為了緩和該第二冷凝器中之甲烷之固化，於本發明中，於第一冷凝器中使蒸發氣體中之甲烷之一部分冷凝，使導入至第二冷凝器之蒸發氣體中之氮濃度上升。藉此，可有效地使甲烷之凝固點下降，結果變得容易防止第二冷凝器中之甲烷固化。即，於第二冷凝器中，即便將蒸發氣體冷卻至第二溫度而甲烷亦不會固化。 In order to alleviate the solidification of methane in the second condenser, in the present invention, one of the methane in the boil-off gas is partially condensed in the first condenser to increase the concentration of nitrogen in the boil-off gas introduced into the second condenser. Thereby, the freezing point of methane can be effectively lowered, and as a result, it is easy to prevent methane from solidifying in the second condenser. That is, in the second condenser, even if the evaporation gas is cooled to the second temperature, methane does not solidify.
又，根據本發明，蒸發氣體係於第一冷凝器中冷卻至第一溫度。第一溫度係較第二溫度高之溫度，故而無於第一冷凝器內甲烷固化之顧慮。 Further, according to the present invention, the boil-off gas system is cooled to a first temperature in the first condenser. The first temperature is higher than the second temperature, so there is no concern that the methane in the first condenser is solidified.
根據以上，根據本發明，於第一冷凝器及第二冷凝器之任一者中甲烷均不會固化，能夠使蒸發氣體再冷凝。 As described above, according to the present invention, methane is not solidified in any of the first condenser and the second condenser, and the evaporated gas can be recondensed.
(發明2) (Invention 2)
本發明之蒸發氣體再冷凝裝置又可為，上述第一冷凝器具備第一熱交換部，上述第二冷凝器具備第二熱交換部，自上述第二熱交換部導出之冷媒之至少一部分導入至上述第一熱交換部。 In the evaporated gas recondensing device of the present invention, the first condenser may include a first heat exchange unit, and the second condenser may include a second heat exchange unit, and at least a part of the refrigerant derived from the second heat exchange unit may be introduced. To the first heat exchange unit.
雖可於第一熱交換部與第二熱交換部中使用不同之冷媒，但將於第二熱交換部中進行了熱交換之冷媒導入至第一熱交換部進一步進行熱交換亦可。根據該構成，經由第二熱交換部之後之冷媒藉由與第二冷凝器內之蒸發 氣體之熱交換而使溫度上升至既定之溫度。該冷媒導入至第一熱交換部，與第一冷凝器內之蒸發氣體進一步進行熱交換，藉此，溫度進一步上升。 Although a different refrigerant may be used in the first heat exchange unit and the second heat exchange unit, the refrigerant that has undergone heat exchange in the second heat exchange unit may be introduced into the first heat exchange unit to further perform heat exchange. According to this configuration, the refrigerant passing through the second heat exchange unit is evaporated by evaporation in the second condenser The heat exchange of the gas causes the temperature to rise to a predetermined temperature. The refrigerant is introduced into the first heat exchange unit, and further exchanges heat with the vaporized gas in the first condenser, whereby the temperature is further increased.
根據以上，第一熱交換部之溫度必然較第二熱交換部高，故而溫度控制容易。又，能夠更有效地使用冷媒之冷熱能。 According to the above, the temperature of the first heat exchange unit is inevitably higher than that of the second heat exchange unit, so that temperature control is easy. Moreover, the cold heat energy of the refrigerant can be used more effectively.
(發明3) (Invention 3)
上述冷媒控制手段亦可具備：冷媒緩衝槽，其儲留冷媒；位準指示調節計及第二冷媒流量調整閥，其等對供給至上述冷媒緩衝槽之上述冷媒之導入量進行控制；循環路徑，其使冷媒自上述冷媒緩衝槽經由上述第二冷凝器之第二熱交換部而返回至上述冷媒緩衝槽；第一冷媒流量調整閥，其配置於上述第二熱交換部與上述冷媒緩衝槽之間之上述循環路徑；第一冷媒返送路徑，其將上述冷媒自上述冷媒緩衝槽向上述第一冷凝器之第一熱交換部傳送；第二壓力指示調整計，其測定自上述第二冷凝器排出之含有氮氣之排出氣體之壓力；及控制部，其基於上述第二壓力指示調整計之測定值對上述冷媒流量調整閥進行控制。 The refrigerant control means may further include: a refrigerant buffer tank that stores a refrigerant; a level indicating regulator and a second refrigerant flow rate adjusting valve that control the amount of introduction of the refrigerant supplied to the refrigerant buffer tank; And returning the refrigerant from the refrigerant buffer tank to the refrigerant buffer tank via the second heat exchange unit of the second condenser; and the first refrigerant flow rate adjustment valve is disposed in the second heat exchange unit and the refrigerant buffer tank a circulation path between the first refrigerant returning path for transferring the refrigerant from the refrigerant buffer tank to a first heat exchange unit of the first condenser; and a second pressure indicating adjuster for measuring the second condensation The pressure of the exhaust gas containing nitrogen gas discharged from the device; and a control unit that controls the refrigerant flow rate adjusting valve based on the measured value of the second pressure indicating adjuster.
上述冷媒控制手段進一步具備配置於上述第一冷媒返送流路之第一冷媒壓力調整閥亦可。 The refrigerant control means may further include a first refrigerant pressure adjusting valve disposed in the first refrigerant return flow path.
上述冷媒壓力調整閥以按照固定壓力(或固定範圍之壓力、既定之壓力)送入冷媒之方式控制閥開度亦可。閥開度係基於藉由配置於第一冷媒返送流路之第一壓力指示調整計而測定出之壓力之測定值進行控制。 The refrigerant pressure regulating valve may control the valve opening degree in such a manner that the refrigerant is supplied to the refrigerant according to a fixed pressure (or a fixed range pressure or a predetermined pressure). The valve opening degree is controlled based on the measured value of the pressure measured by the first pressure indicating adjuster disposed in the first refrigerant return flow path.
向上述第二冷凝器之第二熱交換器傳送之冷媒係自上述冷媒緩衝槽內之上述冷媒之液相部傳送。 The refrigerant sent to the second heat exchanger of the second condenser is transferred from the liquid phase portion of the refrigerant in the refrigerant buffer tank.
向上述第一冷凝器之第一熱交換器傳送之冷媒係自上述冷媒緩衝槽內之上述冷媒之氣相部之至少一部分傳送。 The refrigerant transferred to the first heat exchanger of the first condenser is transferred from at least a portion of the gas phase portion of the refrigerant in the refrigerant buffer tank.
認為於第二熱交換部中，於每當蒸發氣體與冷媒進行熱交換時，導入至第二冷凝器之蒸發氣體之量急遽地減少，或者將過剩之冷媒供給至第二熱交換部之情形時，第二冷凝器內之壓力降低至大氣壓以下(成為負壓)。壓力之降低係於使用液態氮或液態空氣等與蒸發氣體之溫度差較大之溶媒之情形時特別明顯。若第二冷凝器內之壓力成為大氣壓以下，則有空氣自外部混入而與蒸發氣體及/或液化天然氣爆炸性地反應，或冷凝器本身變形，而成為裝置產生故障之原因之虞。 It is considered that in the second heat exchange unit, the amount of the boil-off gas introduced into the second condenser is drastically reduced or the excess refrigerant is supplied to the second heat exchange unit every time the heat exchange between the vaporized gas and the refrigerant is performed. At this time, the pressure in the second condenser is lowered to below atmospheric pressure (becomes a negative pressure). The pressure drop is particularly noticeable when a solvent having a large temperature difference from the vaporized gas such as liquid nitrogen or liquid air is used. When the pressure in the second condenser becomes equal to or lower than atmospheric pressure, air is mixed from the outside to react explosively with the boil-off gas and/or the liquefied natural gas, or the condenser itself is deformed, which may cause the malfunction of the apparatus.
於本發明中，可根據第二熱交換部之內之壓力，調整導入至第二熱交換部之冷媒量，抑制第二冷凝器內成為負壓之現象。即，可以如下方式進行調整：於利用配置於第二排氣配管之第二壓力指示調整計測定出之壓力較預先規定之第一壓力閾值(設為P1)低之情形時，使第二冷媒流量調整閥之開度減少，於第二熱交換部之壓力較第二溫度閾值(設為P2，P2為較P1高之壓力)高之情形時使第二冷媒流量調整閥之開度增加。 In the present invention, the amount of the refrigerant introduced into the second heat exchange unit can be adjusted according to the pressure in the second heat exchange unit, and the phenomenon in which the inside of the second condenser becomes a negative pressure can be suppressed. In other words, the second refrigerant may be adjusted when the pressure measured by the second pressure indicating adjuster disposed in the second exhaust pipe is lower than a predetermined first pressure threshold (set to P1). The opening degree of the flow rate adjusting valve is decreased, and the opening degree of the second refrigerant flow rate adjusting valve is increased when the pressure of the second heat exchange unit is higher than the second temperature threshold (P2, P2 is higher than P1).
藉由將第二冷媒流量調整閥關閉或使閥之開度減少，而使第二熱交換部內之冷媒之壓力上升。其結果，第二熱交換部內之冷媒於第二冷媒送出流路內自第二熱交換部向冷媒緩衝槽之方向逆流。藉此，能夠使冷媒與第二熱交換部內之蒸發氣體之傳熱面積減少，並抑制熱交換。藉由該控制，能夠防止第二冷凝器中之負壓之產生。 The pressure of the refrigerant in the second heat exchange unit is increased by closing the second refrigerant flow rate adjusting valve or reducing the opening degree of the valve. As a result, the refrigerant in the second heat exchange unit flows back from the second heat exchange unit to the refrigerant buffer tank in the second refrigerant supply flow path. Thereby, the heat transfer area of the refrigerant in the refrigerant and the second heat exchange unit can be reduced, and heat exchange can be suppressed. By this control, the generation of the negative pressure in the second condenser can be prevented.
如以上般，根據本發明，藉由調整第二冷媒流量調整閥之開度，可抑制第二冷凝器內成為負壓之現象，且可抑制由來自外部之空氣等之混 入引起之爆炸或冷凝器之變形。進一步，藉由防止外部氣體混入，亦可抑制混入之外部氣體冷凝而使液化天然氣中之雜質增加之現象。 As described above, according to the present invention, by adjusting the opening degree of the second refrigerant flow rate adjusting valve, it is possible to suppress the phenomenon of the negative pressure in the second condenser, and it is possible to suppress the mixing of the air or the like from the outside. Into the resulting explosion or deformation of the condenser. Further, by preventing the intrusion of external air, it is possible to suppress the condensation of the external air mixed and increase the impurities in the liquefied natural gas.
(發明4) (Invention 4)
於本發明之蒸發氣體再冷凝裝置中，上述冷媒可為液態氮及/或液態空氣。 In the evaporated gas recondensing device of the present invention, the refrigerant may be liquid nitrogen and/or liquid air.
冷媒較理想的是具有較蒸發氣體冷凝溫度低之液化溫度。作為具有較蒸發氣體冷凝溫度低之液化溫度之流體可列舉液態氮及液態空氣。液態氮由於為低活性且不可燃，故而當使用於處理可燃性之液化天然氣之設備中時於安全上尤其適合。液態氮必須將氮自空氣分離，相對於此，液態空氣不需要分離操作，故而於能量上較為有利。因此，將液態空氣而並非液態氮用作冷媒亦可。 The refrigerant preferably has a liquefaction temperature lower than the condensation temperature of the vaporized gas. As the fluid having a liquefaction temperature lower than the condensation temperature of the vaporized gas, liquid nitrogen and liquid air can be cited. Liquid nitrogen is particularly suitable for safety when used in equipment for treating flammable liquefied natural gas because it is low in activity and non-flammable. Liquid nitrogen must separate nitrogen from the air. In contrast, liquid air does not require a separation operation and is therefore advantageous in terms of energy. Therefore, it is also possible to use liquid air instead of liquid nitrogen as a refrigerant.
藉由使蒸發氣體與液態氮熱交換，進一步讓液態氮與液態空氣熱交換而冷卻、再液化後再利用亦可。 By exchanging heat between the boil-off gas and the liquid nitrogen, the liquid nitrogen can be further exchanged by heat exchange with the liquid air, and then re-liquefied and reused.
使液態氮與液態空氣之混合物為冷媒亦可。 A mixture of liquid nitrogen and liquid air may be used as a refrigerant.
(發明5) (Invention 5)
於本發明之蒸發氣體再冷凝裝置之冷媒為氮之情形時，可具有於上述第二冷凝器內之壓力成為預先規定之下限界值以下時，將上述第一冷媒送出流路內之氮氣導入至上述第二冷凝器內之壓力控制用氮導入路徑。 In the case where the refrigerant in the evaporating gas recondensing device of the present invention is nitrogen, when the pressure in the second condenser is equal to or lower than a predetermined lower limit value, the nitrogen gas in the first refrigerant sending flow path may be introduced. The pressure control nitrogen introduction path to the second condenser.
根據該發明，於第二冷凝器內之壓力成為預先規定之下限值(設為PTH，例如為1.00bar)以下之情形時，將用作冷媒之氮氣導入至第二冷凝器內，可防止第二冷凝器內成為負壓。雖可單獨地具備該負壓防止對策，但作為於具備上述發明3所示之負壓防止對策時，即便有發明3之應對但仍會成為低於上述下限值之壓力之情形時的預備性對策而具備亦可。於該情形時，較發明3中之第一壓力閾值P1而上述下限值PTH成為較低之壓力值。 According to the invention, the pressure within the second condenser become below a predetermined value (set P TH, for example 1.00bar) less the case when, as the refrigerant of nitrogen gas introduced into the second condenser, may be The inside of the second condenser is prevented from becoming a negative pressure. In addition to the negative pressure prevention measures described in the third aspect of the invention, it is possible to prepare the negative pressure prevention measures as described in the third aspect of the invention, even if the pressure of the invention is not lower than the lower limit value. It is also possible to take measures. In this case, the lower limit value P TH is lower than the first pressure threshold P1 in the third invention.
(發明7) (Invention 7)
本發明之液化天然氣儲藏系統具備：如發明1至發明6中任一項之蒸發氣體再冷凝裝置；液化天然氣槽，其儲藏液化天然氣；液化天然氣槽蒸發氣體排出配管，其將上述液化天然氣槽內之蒸發氣體導入至上述液化天然氣緩衝槽；及液化天然氣緩衝槽液化天然氣排出配管，其將上述液化天然氣緩衝槽內之液化天然氣之液相之至少一部分返送至上述液化天然氣槽內。 The liquefied natural gas storage system of the present invention comprises: the evaporated gas recondensing device according to any one of Inventions 1 to 6; a liquefied natural gas tank storing the liquefied natural gas; and a liquefied natural gas tank evaporating gas discharge pipe, which is disposed in the liquefied natural gas tank The evaporating gas is introduced into the liquefied natural gas buffer tank; and the liquefied natural gas buffer tank liquefied natural gas discharge piping returns at least a part of the liquid phase of the liquefied natural gas in the liquefied natural gas buffer tank to the liquefied natural gas tank.
亦能夠於已自液化天然氣船等接收液化天然氣之液化天然氣槽直接安裝用以使液化天然氣再冷凝之冷凝器，使再冷凝蒸發氣體直接返送至液化天然氣槽。另一方面，亦可使再冷凝蒸發氣體先由液化天然氣緩衝槽接收，然後利用泵等自液化天然氣緩衝槽返送至液化天然氣槽。液化天然氣緩衝槽具有確保泵之NPSH(Net Positive Suction Head，淨有效吸水頭)之功能。又，具有如下功能：於將再冷凝蒸發氣體自該液化天然氣緩衝槽向液化天然氣槽返送時，藉由使液化天然氣槽內之氣相部分由液化天然氣緩衝槽接收，而使液化天然氣槽之壓力上升減少。 It is also possible to directly install a condenser for recondensing the liquefied natural gas in a liquefied natural gas tank that has received liquefied natural gas from a liquefied natural gas carrier, and to directly return the recondensed evaporated gas to the liquefied natural gas tank. On the other hand, the recondensed boil-off gas may be first received by the liquefied natural gas buffer tank and then returned to the liquefied natural gas tank from a liquefied natural gas buffer tank by means of a pump or the like. The LNG buffer tank has the function of ensuring the pump's NPSH (Net Positive Suction Head). Moreover, the function of: when the recondensed boil-off gas is returned from the liquefied natural gas buffer tank to the liquefied natural gas tank, the pressure of the liquefied natural gas tank is made by receiving the gas phase portion in the liquefied natural gas tank from the liquefied natural gas buffer tank. The increase is reduced.
1‧‧‧蒸發氣體再冷凝裝置 1‧‧‧Boiling gas recondensing unit
11‧‧‧蒸發氣體導出配管 11‧‧‧Evaporation gas export piping
12‧‧‧液化天然氣緩衝槽 12‧‧‧ LNG buffer tank
13‧‧‧冷媒緩衝槽 13‧‧‧Refrigerant buffer tank
21‧‧‧第一冷媒流量調整閥 21‧‧‧First refrigerant flow adjustment valve
22‧‧‧第二冷媒流量調整閥 22‧‧‧Second refrigerant flow adjustment valve
23‧‧‧排氣壓力調整閥 23‧‧‧Exhaust pressure regulating valve
25‧‧‧冷媒壓力調整閥 25‧‧‧Refrigerant pressure regulating valve
33‧‧‧液化天然氣槽 33‧‧‧LNG tank
111‧‧‧第一冷凝器 111‧‧‧First condenser
112‧‧‧第一熱交換部 112‧‧‧First Heat Exchange Department
113‧‧‧第一返送配管 113‧‧‧First return piping
114‧‧‧第一氣體供給部 114‧‧‧First Gas Supply Department
115‧‧‧第一冷媒返送流路 115‧‧‧The first refrigerant return flow path
116‧‧‧第一冷媒送出流路 116‧‧‧The first refrigerant delivery channel
211‧‧‧第二冷凝器 211‧‧‧second condenser
212‧‧‧第二熱交換部 212‧‧‧Second Heat Exchange Department
213‧‧‧第二返送配管 213‧‧‧Second return piping
214‧‧‧第二排氣配管 214‧‧‧Second exhaust piping
215‧‧‧第二冷媒返送流路 215‧‧‧Second refrigerant return flow path
216‧‧‧第二冷媒送出流路 216‧‧‧Second refrigerant delivery flow path
301‧‧‧位準指示調整計 301‧‧‧ Quasi-instruction adjustment meter
302‧‧‧第一壓力指示調整計 302‧‧‧First pressure indicator adjustment meter
303‧‧‧運算部 303‧‧‧ Computing Department
304‧‧‧第一壓力指示調整計 304‧‧‧First Pressure Indicator Adjustment Meter
305‧‧‧第三壓力指示調整計 305‧‧‧ Third pressure indicator adjustment meter
401‧‧‧泵 401‧‧‧ pump
圖1係表示實施形態1之蒸發氣體再冷凝裝置之構成例之圖。 Fig. 1 is a view showing a configuration example of an evaporating gas recondensing device of the first embodiment.
圖2係表示實施形態2之蒸發氣體再冷凝裝置之構成例之圖。 Fig. 2 is a view showing a configuration example of an evaporation gas recondensing device of the second embodiment.
圖3係表示實施形態3之蒸發氣體再冷凝裝置之構成例之圖。 Fig. 3 is a view showing a configuration example of an evaporation gas recondensing device of the third embodiment.
圖4係表示實施形態4之液化天然氣儲藏系統之構成例之圖。 Fig. 4 is a view showing a configuration example of a liquefied natural gas storage system according to a fourth embodiment.
圖5係表示實施例1之蒸發氣體再冷凝裝置之構成及資料測定部位之圖。 Fig. 5 is a view showing the configuration of a vaporized gas recondensing device of the first embodiment and a data measuring portion.
以下對本發明之幾個實施形態進行說明。以下將說明之實施形 態係說明本發明之一例者。本發明並不受以下之實施形態任何限定，亦包含於不變更本發明之主旨之範圍中實施之各種變形形態。再者，並未限定以下將說明之構成全部為本發明必須之構成。 Several embodiments of the present invention will be described below. The following will describe the implementation The state illustrates one example of the invention. The present invention is not limited to the embodiments described below, and various modifications may be made without departing from the spirit and scope of the invention. Furthermore, the configurations described below are not necessarily all the necessary configurations of the present invention.
(實施形態1) (Embodiment 1)
參照圖1對實施形態1之蒸發氣體再冷凝裝置進行說明。 The evaporated gas recondensing device of the first embodiment will be described with reference to Fig. 1 .
蒸發氣體再冷凝裝置1具有液化天然氣緩衝槽12、第一冷凝器111、及第二冷凝器211。第一冷凝器111具有第一熱交換部112。第二冷凝器211具有第二熱交換部212。 The boil-off gas recondensing device 1 has a liquefied natural gas buffer tank 12, a first condenser 111, and a second condenser 211. The first condenser 111 has a first heat exchange portion 112. The second condenser 211 has a second heat exchange portion 212.
液化天然氣緩衝槽12只要為具有可儲藏液化天然氣之構造者即可，自液化天然氣船等直接接收液化天然氣亦可，為暫時保存使從自液化天然氣船接收液化天然氣之液化天然氣槽(未圖示)產生之蒸發氣體再冷凝後所得之再冷凝蒸發氣體的緩衝槽亦可。 The liquefied natural gas buffer tank 12 may be a structure capable of storing liquefied natural gas, and may directly receive liquefied natural gas from a liquefied natural gas ship or the like, and may temporarily store liquefied natural gas tanks for receiving liquefied natural gas from a liquefied natural gas ship (not shown). The buffer tank for recondensing the evaporated gas obtained by re-condensing the generated vaporized gas may also be used.
於液化天然氣緩衝槽12內產生之蒸發氣體自蒸發氣體導出配管11向第一冷凝器111導入。向第一冷凝器111導入之蒸發氣體之至少一部分藉由於第一熱交換部112內與冷媒之熱交換，而冷卻至第一溫度(例如-152℃)，並再冷凝。上述第一溫度只要為蒸發氣體之一部分會再冷凝之溫度，且為不會產生甲烷之急遽固化之溫度即可，例如只要為-162℃至-150℃之範圍即可。 The boil-off gas generated in the liquefied natural gas buffer tank 12 is introduced into the first condenser 111 from the boil-off gas outlet pipe 11. At least a portion of the boil-off gas introduced into the first condenser 111 is cooled to a first temperature (for example, -152 ° C) by heat exchange with the refrigerant in the first heat exchange portion 112, and is further condensed. The first temperature may be a temperature at which a part of the vaporized gas is recondensed, and may be a temperature at which no rapid solidification of methane occurs, and may be, for example, a range of -162 ° C to -150 ° C.
如圖1所示，第一冷凝器111與第二冷凝器211亦可並列地設置於液化天然氣緩衝槽12之上部。於該情形時，第一氣體供給部114亦可為將自第一冷凝器111導出之氣體向第二冷凝器211導入之氣體供給配管。 As shown in FIG. 1, the first condenser 111 and the second condenser 211 may be disposed side by side in the upper portion of the liquefied natural gas buffer tank 12. In this case, the first gas supply unit 114 may be a gas supply pipe that introduces the gas derived from the first condenser 111 into the second condenser 211.
於本發明中，又，第一冷凝器111與第二冷凝器211亦可串聯地配置於液化天然氣緩衝槽12之上部(未圖示)。於該情形時，第一氣體供給部114位於第一冷凝器111與第二冷凝器211之中間部。 In the present invention, the first condenser 111 and the second condenser 211 may be disposed in series above the liquefied natural gas buffer tank 12 (not shown). In this case, the first gas supply portion 114 is located at an intermediate portion between the first condenser 111 and the second condenser 211.
於本發明中，液化天然氣緩衝槽12只要為供給、儲藏液化天然氣之儲槽則 並不特別限定，為進行液化天然氣之一次儲藏之儲槽亦可，為於進行液化天然氣之一次儲藏之儲槽中進行暫時儲藏以供於第一冷凝器及/或第二冷凝器中冷凝之蒸發氣體返送之緩衝槽亦可。 In the present invention, the liquefied natural gas buffer tank 12 is only required to supply and store a liquefied natural gas storage tank. The storage tank for performing the primary storage of the liquefied natural gas may be temporarily stored in a storage tank for performing primary storage of the liquefied natural gas for condensation in the first condenser and/or the second condenser. The buffer tank for returning the vaporized gas may also be used.
於第一冷凝器111內再冷凝後之蒸發氣體經由第一返送配管113而向液化天然氣緩衝槽12返送。導入至第一冷凝器111之蒸發氣體中之於第一冷凝器111內未冷凝之部分自第一氣體供給部114向第二冷凝器211導入。向第二冷凝器211導入之蒸發氣體藉由經由第一冷凝器111，而較液化天然氣緩衝槽12內之蒸發氣體含有更多氮成分。 The boil-off gas recondensed in the first condenser 111 is returned to the liquefied natural gas buffer tank 12 via the first return pipe 113. A portion of the boil-off gas introduced into the first condenser 111 that is not condensed in the first condenser 111 is introduced from the first gas supply unit 114 to the second condenser 211. The boil-off gas introduced into the second condenser 211 passes through the first condenser 111, and the vaporized gas in the liquefied natural gas buffer tank 12 contains more nitrogen components.
向第二冷凝器211導入之蒸發氣體之至少一部分於第二熱交換部212與冷媒進行熱交換，藉此冷卻至第二溫度(例如-185℃)，並再冷凝。第二溫度只要為較上述第一溫度低，且可充分使蒸發氣體再冷凝之溫度即可，例如只要為-190℃至-182℃之範圍即可。由於第二熱交換部212內之蒸發氣體含有較多氮成分，故而藉由液化天然氣之凝固點下降之效果而使得即便為較作為純粹之液化天然氣之凝固點之-182℃低之溫度亦不會凝固。再冷凝後之蒸發氣體經由第二返送配管213而向液化天然氣緩衝槽12返送。 At least a portion of the boil-off gas introduced into the second condenser 211 is heat-exchanged with the refrigerant in the second heat exchange portion 212, thereby being cooled to a second temperature (for example, -185 ° C), and recondensed. The second temperature may be a temperature lower than the first temperature and sufficient to recondense the evaporated gas, and may be, for example, in the range of -190 ° C to -182 ° C. Since the boil-off gas in the second heat exchange unit 212 contains a large amount of nitrogen, the effect of lowering the freezing point of the liquefied natural gas does not cause solidification even at a temperature lower than -182 ° C which is a freezing point of pure liquefied natural gas. . The recondensed vaporized gas is returned to the liquefied natural gas buffer tank 12 via the second return pipe 213.
於第二熱交換部212中使用之冷媒自第二冷媒緩衝槽501導入至第二熱交換部212，於與第二冷凝器211內之蒸發氣體進行熱交換之後經由第二冷媒送出流路216而向第一熱交換部112導入。向第一熱交換部112導入之冷媒進一步與第一冷凝器111內之蒸發氣體進行熱交換。冷媒之溫度於第二熱交換部212中以上述第二溫度與蒸發氣體進行熱交換之後，上升至較上述第二溫度高之上述第一溫度。具有第一溫度之冷媒於第一冷凝器111內之第一熱交換部112中與蒸發氣體進行熱交換。 The refrigerant used in the second heat exchange unit 212 is introduced into the second heat exchange unit 212 from the second refrigerant buffer tank 501, and is exchanged with the vaporized gas in the second condenser 211, and then sent to the flow path 216 via the second refrigerant. The introduction is performed to the first heat exchange unit 112. The refrigerant introduced into the first heat exchange unit 112 further exchanges heat with the vaporized gas in the first condenser 111. The temperature of the refrigerant is exchanged with the boil-off gas at the second temperature in the second heat exchange unit 212, and then rises to the first temperature higher than the second temperature. The refrigerant having the first temperature exchanges heat with the boil-off gas in the first heat exchange portion 112 in the first condenser 111.
冷媒只要於第一溫度及第二溫度中為液體狀態或氣體狀態即可，例如可使用氮、空氣、氮與空氣之混合體。於使用氮作為冷媒之情形時， 冷媒之氮係以液體狀態向第二熱交換部212導入。液態氮於第二熱交換部212中與蒸發氣體進行熱交換之後，經由第二冷媒送出流路216而向第一熱交換部112導入。冷媒雖可以液體狀態向第一熱交換部112導入，以冷媒之一部分或全部氣化之狀態向第一熱交換部112導入亦可。於第一熱交換部111中進行了熱交換之後，成為冷媒之一部分或全部氣化之狀態。該冷媒雖可廢棄，但再次冷卻後液化，並再利用亦可。 The refrigerant may be in a liquid state or a gas state at the first temperature and the second temperature, and for example, a mixture of nitrogen, air, nitrogen, and air may be used. When using nitrogen as a refrigerant, The nitrogen of the refrigerant is introduced into the second heat exchange unit 212 in a liquid state. The liquid nitrogen is heat-exchanged with the boil-off gas in the second heat exchange unit 212, and then introduced into the first heat exchange unit 112 via the second refrigerant supply flow path 216. The refrigerant may be introduced into the first heat exchange unit 112 in a liquid state, and may be introduced into the first heat exchange unit 112 in a state in which one or all of the refrigerant is vaporized. After heat exchange is performed in the first heat exchange unit 111, it is in a state in which part or all of the refrigerant is vaporized. Although the refrigerant can be discarded, it can be liquefied after being cooled again and reused.
(實施形態2) (Embodiment 2)
參照圖2對實施形態2之蒸發氣體再冷凝裝置2進行說明。由於與實施形態1之蒸發氣體再冷凝裝置1相同之符號之要素具有相同之功能，故而省略其說明。 The evaporated gas recondensing device 2 of the second embodiment will be described with reference to Fig. 2 . Since the elements of the same reference numerals as those of the evaporated gas recondensing device 1 of the first embodiment have the same functions, the description thereof will be omitted.
如圖2所示，於第一熱交換部112中使用之冷媒與於第二熱交換部212中使用之冷媒亦可不同。於該情形時，於第一熱交換部112內流通之第一冷媒之溫度控制為上述第一溫度，於第二熱交換部212內流通之第二冷媒之溫度控制為上述第二溫度。 As shown in FIG. 2, the refrigerant used in the first heat exchange unit 112 may be different from the refrigerant used in the second heat exchange unit 212. In this case, the temperature of the first refrigerant flowing through the first heat exchange unit 112 is controlled to the first temperature, and the temperature of the second refrigerant flowing through the second heat exchange unit 212 is controlled to the second temperature.
第一冷媒係自第一冷媒緩衝槽503經由第一冷媒流路504而傳送至第一冷凝器111中之第一熱交換部112。第一冷媒藉由設置於第一冷媒緩衝槽503之溫度調整機構(未圖示)而控制為既定之溫度亦可。藉由設置於第一冷媒流路504之流量計(未圖示)而控制第一冷媒之流量以使第一熱交換部112內成為第一溫度亦可。 The first refrigerant is transferred from the first refrigerant buffer tank 503 to the first heat exchange unit 112 in the first condenser 111 via the first refrigerant flow path 504. The first refrigerant may be controlled to a predetermined temperature by a temperature adjustment mechanism (not shown) provided in the first refrigerant buffer tank 503. The flow rate of the first refrigerant is controlled by a flow meter (not shown) provided in the first refrigerant flow path 504 so that the inside of the first heat exchange unit 112 becomes the first temperature.
同樣地，第二冷媒係自第二冷媒緩衝槽501經由第二冷媒流路502而傳送至第二冷凝器211中之第二熱交換部212。第二冷媒藉由設置於第二冷媒緩衝槽501之溫度調整機構(未圖示)而控制為既定之溫度亦可。藉由設置於第二冷媒流路502之流量計(未圖示)而控制第二冷媒之流量以使第二熱交換部212內成為第二溫度亦可。 Similarly, the second refrigerant is transferred from the second refrigerant buffer tank 501 to the second heat exchange portion 212 of the second condenser 211 via the second refrigerant flow path 502. The second refrigerant may be controlled to a predetermined temperature by a temperature adjustment mechanism (not shown) provided in the second refrigerant buffer tank 501. The flow rate of the second refrigerant is controlled by a flow meter (not shown) provided in the second refrigerant flow path 502 so that the inside of the second heat exchange unit 212 becomes the second temperature.
(實施形態3) (Embodiment 3)
參照圖3對實施形態3之蒸發氣體再冷凝裝置3進行說明。由於與實施形態1之蒸發氣體再冷凝裝置1、實施形態2之蒸發氣體再冷凝裝置2相同之符號之要素具有相同之功能，故而省略其說明。 The evaporated gas recondensing device 3 of the third embodiment will be described with reference to Fig. 3 . Since the elements of the same reference numerals as those of the evaporated gas recondensing device 1 of the first embodiment and the evaporated gas recondensing device 2 of the second embodiment have the same functions, the description thereof will be omitted.
雖可自第二熱交換部212向第一熱交換部112直接導入冷媒，如圖3所示，經由冷媒緩衝槽13而導入亦可。 The refrigerant may be directly introduced into the first heat exchange unit 112 from the second heat exchange unit 212, and may be introduced through the refrigerant buffer tank 13 as shown in FIG.
自第二熱交換部212導出之冷媒自第二冷媒送出流路216導入至冷媒緩衝槽13。導入至冷媒緩衝槽13之冷媒中之液相部分儲留於冷媒緩衝槽13之下方，自第二冷媒返送流路215再次向第二熱交換部212傳送。導入至冷媒緩衝槽13之冷媒中之氣相部分儲留於冷媒緩衝槽13之上方，自第一冷媒返送流路115向第一熱交換部112傳送。 The refrigerant derived from the second heat exchange unit 212 is introduced into the refrigerant buffer tank 13 from the second refrigerant delivery flow path 216. The liquid phase portion of the refrigerant introduced into the refrigerant buffer tank 13 is stored below the refrigerant buffer tank 13, and is again transferred from the second refrigerant return flow path 215 to the second heat exchange portion 212. The gas phase portion of the refrigerant introduced into the refrigerant buffer tank 13 is stored above the refrigerant buffer tank 13, and is transported from the first refrigerant return flow path 115 to the first heat exchange portion 112.
冷媒於冷媒緩衝槽13內冷卻而使一部分被液化亦可。冷媒之冷卻使用例如液態空氣或液態氮亦可。雖可使用液態氮作為冷媒，液態氮之冷卻使用液態氮亦可，但使用液態空氣亦可。 The refrigerant may be cooled in the refrigerant buffer tank 13 to be partially liquefied. The cooling of the refrigerant may be carried out using, for example, liquid air or liquid nitrogen. Although liquid nitrogen can be used as the refrigerant, liquid nitrogen can be cooled by liquid nitrogen, but liquid air can also be used.
冷媒先導入至冷媒緩衝槽13，與循環之冷媒混合而供給至第二熱交換部212。系統內之冷媒量係藉由位準指示計301而指示，若冷媒量減少則打開第二冷媒流調整閥22並追加冷媒。 The refrigerant is first introduced into the refrigerant buffer tank 13, mixed with the circulating refrigerant, and supplied to the second heat exchange unit 212. The amount of refrigerant in the system is indicated by the level indicator 301. When the amount of refrigerant decreases, the second refrigerant flow regulating valve 22 is opened and the refrigerant is added.
若藉由於熱交換部212內與蒸發氣體進行熱交換，而使冷媒之一部分氣化，則就冷媒之氣相部分而言，自第二冷媒送出流路216而使冷媒緩衝槽13中之氣相部之壓力上升，自冷媒緩衝槽13之下方將冷媒之液相部分推出。被推出之冷媒自第二冷媒返送流路215向第二熱交換部212導入。因此，冷媒緩衝槽13與第二熱交換部212之間之冷媒之移動可不使用泵等之動力而實施。 When a part of the refrigerant is vaporized by heat exchange with the boil-off gas in the heat exchange unit 212, the gas phase of the refrigerant is sent from the second refrigerant to the flow path 216 to make the gas in the refrigerant buffer tank 13 The pressure of the phase rises, and the liquid phase portion of the refrigerant is pushed out from below the refrigerant buffer tank 13. The introduced refrigerant is introduced into the second heat exchange unit 212 from the second refrigerant return flow path 215. Therefore, the movement of the refrigerant between the refrigerant buffer tank 13 and the second heat exchange unit 212 can be performed without using the power of a pump or the like.
於第二冷媒送出流路216配置有第一冷媒流量調整閥21。第一冷媒流量調整閥21通常以全開狀態運用。 The first refrigerant flow rate adjustment valve 21 is disposed in the second refrigerant delivery flow path 216. The first refrigerant flow rate adjustment valve 21 is normally operated in a fully open state.
若於第二熱交換部212中因蒸發氣體過度冷凝等而使第二熱交換部212內之蒸發氣體壓力降低，則第二熱交換部212內之壓力相對於大氣壓成為負壓。藉此會導致大氣混入第二熱交換部212內之蒸發氣體從而造成污染，或會導致第二熱交換部212之損壞。 When the pressure of the vaporized gas in the second heat exchange unit 212 is lowered by the excessive condensation of the evaporated gas in the second heat exchange unit 212, the pressure in the second heat exchange unit 212 becomes a negative pressure with respect to the atmospheric pressure. Thereby, the atmosphere is mixed into the vaporized gas in the second heat exchange portion 212 to cause contamination, or the second heat exchange portion 212 may be damaged.
為了解決該問題，利用第一壓力指示調整計304偵測第二熱交換部212內之蒸發氣體壓力，於判斷為由運算部303偵測出之蒸發氣體側壓力低於閾值之情形時，進行將第一冷媒流量調整閥21關閉之控制。 In order to solve this problem, the first pressure indicating adjuster 304 detects the evaporation gas pressure in the second heat exchange unit 212, and when it is determined that the evaporation gas side pressure detected by the calculation unit 303 is lower than the threshold value, The control of closing the first refrigerant flow rate adjusting valve 21 is performed.
此處，第一壓力指示調整計304配置於第二排氣配管214上，第二排氣配管214之壓力成為與第二熱交換部212內部之壓力同等之壓力，故而能夠藉由第一壓力指示調整計304而檢測第二熱交換部212內之壓力。 Here, the first pressure indicating adjuster 304 is disposed on the second exhaust pipe 214, and the pressure of the second exhaust pipe 214 is equal to the pressure inside the second heat exchange portion 212, so that the first pressure can be utilized. The regulator 304 is instructed to detect the pressure in the second heat exchange unit 212.
藉由將第一冷媒流量調整閥21關閉之控制，而於第二熱交換部212內藉由熱交換而產生之蒸發氣體蓄積於第二熱交換部212之上部，因其壓力而將液冷媒推回至冷媒緩衝槽13。於是，可使第二熱交換部212中之熱交換停止，結果可使蒸發氣體之進一步冷凝停止，防止第二熱交換部212內之蒸發氣體壓力成為負壓。若第二熱交換部212內之冷媒之液相部分自第二冷媒返送流路向冷媒緩衝槽13逆流，則第二熱交換部212內之冷媒之液面降低。其結果，第二熱交換部212內之蒸發氣體與液相之冷媒之傳熱面積減少，可抑制蒸發氣體過度冷卻之現象。於第二熱交換部212內之溫度上升之情形時可使第一冷媒流量調整閥21之開度上升，使第二熱交換部212內之冷媒之液面上升，使蒸發氣體溫度降低。 By controlling the first refrigerant flow rate adjusting valve 21 to be closed, the vaporized gas generated by the heat exchange in the second heat exchange unit 212 is accumulated in the upper portion of the second heat exchange unit 212, and the liquid refrigerant is pressurized by the pressure. Push back to the refrigerant buffer tank 13. Then, the heat exchange in the second heat exchange portion 212 can be stopped, and as a result, further condensation of the vaporized gas can be stopped, and the pressure of the vaporized gas in the second heat exchange portion 212 can be prevented from becoming a negative pressure. When the liquid phase portion of the refrigerant in the second heat exchange unit 212 flows back from the second refrigerant return flow path to the refrigerant buffer tank 13, the liquid level of the refrigerant in the second heat exchange unit 212 is lowered. As a result, the heat transfer area of the evaporation gas in the second heat exchange unit 212 and the refrigerant in the liquid phase is reduced, and the phenomenon that the evaporation gas is excessively cooled can be suppressed. When the temperature in the second heat exchange unit 212 rises, the opening degree of the first refrigerant flow rate adjustment valve 21 can be increased, and the liquid level of the refrigerant in the second heat exchange unit 212 can be raised to lower the temperature of the evaporation gas.
第二熱交換部212之溫度既可藉由檢測第二熱交換部212之壁面之溫度或內部之冷媒溫度而測定，藉由檢測自第二熱交換部212排出之廢棄氮氣之溫度而取得亦可。 The temperature of the second heat exchange unit 212 can be measured by detecting the temperature of the wall surface of the second heat exchange unit 212 or the temperature of the internal refrigerant, and detecting the temperature of the waste nitrogen gas discharged from the second heat exchange unit 212. can.
冷媒必須以如於第二熱交換部212中蒸發氣體不固化之溫度下運用，其溫 度控制較佳為考慮了冷媒之氣液平衡之壓力控制。因此，以控制第二熱交換部212之運轉壓力之方式，藉由測定與調整第一冷媒供給流路115之壓力之第一壓力指示調整計302，而將冷媒壓力調整閥25開閉。 The refrigerant must be applied at a temperature such as that the evaporation gas in the second heat exchange portion 212 is not solidified, and the temperature thereof is used. The degree of control is preferably a pressure control in consideration of the gas-liquid equilibrium of the refrigerant. Therefore, the refrigerant pressure adjusting valve 25 is opened and closed by measuring the first pressure indicating adjuster 302 that adjusts the pressure of the first refrigerant supply flow path 115 so as to control the operating pressure of the second heat exchange unit 212.
以控制第二熱交換部212內之蒸發氣體壓力之方式，藉由第三壓力指示調整計305而將排氣壓力調整閥23開閉。 The exhaust pressure regulating valve 23 is opened and closed by the third pressure indicating adjustment meter 305 so as to control the pressure of the evaporation gas in the second heat exchange unit 212.
如以上所述，藉由控制第二冷媒流量調整閥21，即便於蒸發氣體之熱量變動較大之情形時亦可迅速地進行溫度調節，有效地使蒸發氣體再冷凝。 As described above, by controlling the second refrigerant flow rate adjusting valve 21, even when the heat of the vaporized gas fluctuates greatly, the temperature can be quickly adjusted to effectively condense the evaporated gas.
於第二冷媒送出流路216配置有第二冷媒流量調節閥21。於第二熱交換部212之溫度較預先規定之既定之溫度T1(於本實施形態中為-182℃)降低之情形時，或於第二熱交換部212內之壓力較預先規定之既定之壓力P1(於本實施形態中為4bar)降低之情形時，可將第二冷媒流量調節閥21關閉，或使開度減少而使第二熱交換部212內之冷媒之氣相部之壓力上升。藉此，第二熱交換部212內之冷媒之液相部分自第二冷媒返送流路向冷媒緩衝槽13逆流，第二熱交換部212內之冷媒之液面降低。其結果，第二熱交換部212內中之蒸發氣體與液相之冷媒之傳熱面積減少，可抑制蒸發氣體過度地冷卻之現象。於第二熱交換部212內之溫度上升之情形時，可使第二冷媒流量調整閥21之開度上升，使第二熱交換部212內之冷媒之液面上升，使蒸發氣體溫度降低。 The second refrigerant flow control valve 21 is disposed in the second refrigerant delivery flow path 216. When the temperature of the second heat exchange unit 212 is lower than a predetermined temperature T1 (in the present embodiment, -182 ° C), or the pressure in the second heat exchange unit 212 is predetermined. When the pressure P1 (4 bar in the present embodiment) is lowered, the second refrigerant flow rate adjusting valve 21 may be closed, or the opening degree may be decreased to increase the pressure of the gas phase portion of the refrigerant in the second heat exchange portion 212. . Thereby, the liquid phase portion of the refrigerant in the second heat exchange unit 212 flows back from the second refrigerant return flow path to the refrigerant buffer tank 13, and the liquid level of the refrigerant in the second heat exchange unit 212 is lowered. As a result, the heat transfer area of the evaporation gas in the second heat exchange unit 212 and the refrigerant in the liquid phase is reduced, and the phenomenon that the evaporation gas is excessively cooled can be suppressed. When the temperature in the second heat exchange unit 212 rises, the opening degree of the second refrigerant flow rate adjustment valve 21 can be increased, and the liquid level of the refrigerant in the second heat exchange unit 212 can be raised to lower the temperature of the evaporation gas.
上述既定之壓力P1只要為大氣壓以上即可，第二冷凝器211內之壓力降低至大氣壓以下，可抑制產生冷凝器之變形或故障。 The predetermined pressure P1 may be equal to or higher than atmospheric pressure, and the pressure in the second condenser 211 may be lowered to below atmospheric pressure to suppress deformation or failure of the condenser.
第二熱交換部212之溫度既可藉由檢測第二熱交換部212之壁面之溫度或內部之冷媒溫度而測定，藉由檢測自第二熱交換部212排出之廢棄氮氣之溫度而取得亦可。 The temperature of the second heat exchange unit 212 can be measured by detecting the temperature of the wall surface of the second heat exchange unit 212 or the temperature of the internal refrigerant, and detecting the temperature of the waste nitrogen gas discharged from the second heat exchange unit 212. can.
於第二冷凝器211內之壓力較預先規定之既定之壓力P1進一步降低並到達至下限值之情形時(設為下限值PTH，下限值PTH為較P1低之壓力)， 將自第一熱交換部112排出之冷媒(於本實施形態中為氮氣)導入至第二冷凝器212。P0只要為較P1低且較大氣壓高之值即可，於本實施形態中為4bar。藉由配置於第二排氣配管214之壓力計而檢測第二冷凝器211內之壓力，於經檢測出之壓力較PTH低之情形時，將第四冷媒流量調整閥24打開而使第一冷媒送出流路116內之氮氣經由第二排氣配管214，導入至第二冷凝器211內。藉此，可防止第二冷凝器211進一步成為負壓。 When the pressure in the second condenser 211 is further lowered than the predetermined pressure P1 which is predetermined and reaches the lower limit value (set to the lower limit value P TH , the lower limit value P TH is a pressure lower than P1), The refrigerant (nitrogen gas in the present embodiment) discharged from the first heat exchange unit 112 is introduced into the second condenser 212. P0 may be a value lower than P1 and a higher atmospheric pressure, and is 4 bar in this embodiment. The pressure in the second condenser 211 is detected by a pressure gauge disposed in the second exhaust pipe 214. When the detected pressure is lower than the P TH , the fourth refrigerant flow rate adjusting valve 24 is opened to make the first The nitrogen gas in the refrigerant supply flow path 116 is introduced into the second condenser 211 via the second exhaust pipe 214. Thereby, the second condenser 211 can be prevented from further becoming a negative pressure.
(實施形態4) (Embodiment 4)
參照圖4對實施形態4之液化天然氣儲藏系統4進行說明。由於與實施形態1~3之蒸發氣體再冷凝裝置1~3相同之符號之要素具有相同之功能，故而省略其說明。 The liquefied natural gas storage system 4 of the fourth embodiment will be described with reference to Fig. 4 . Since the elements of the same reference numerals as those of the evaporated gas recondensing apparatuses 1 to 3 of the first to third embodiments have the same functions, the description thereof will be omitted.
實施形態4之液化天然氣儲藏系統4具有接收移送來之液化天然氣之液化天然氣槽33、及接收液化天然氣槽內之蒸發氣體之液化天然氣緩衝槽12。液化天然氣槽33內之蒸發氣體一次性地儲留於液化天然氣緩衝槽12，然後藉由實施形態1之液化天然氣冷凝裝置1而再冷凝。再冷凝後儲留於液化天然氣緩衝槽12內之再冷凝蒸發氣體藉由泵401而向液化天然氣槽33返送。若自液化天然氣緩衝槽12接收再冷凝蒸發氣體，則液化天然氣槽33內之液相(LNG)之容積增加，氣相(BOG)部分之壓力上升。於在液化天然氣槽33設置測定液化天然氣槽內之壓力之壓力計(未圖示)，液化天然氣槽33內之壓力較既定之閾值(例如1.1bar)高之情形時，進行控制以於液化天然氣緩衝槽12內接收液化天然氣槽33內之蒸發氣體亦可。 The liquefied natural gas storage system 4 of the fourth embodiment has a liquefied natural gas tank 33 that receives the transferred liquefied natural gas, and a liquefied natural gas buffer tank 12 that receives the evaporated gas in the liquefied natural gas tank. The vaporized gas in the liquefied natural gas tank 33 is once stored in the liquefied natural gas buffer tank 12, and then recondensed by the liquefied natural gas condensing unit 1 of the first embodiment. The recondensed boil-off gas stored in the liquefied natural gas buffer tank 12 after recondensation is returned to the liquefied natural gas tank 33 by the pump 401. When the re-condensed boil-off gas is received from the liquefied natural gas buffer tank 12, the volume of the liquid phase (LNG) in the liquefied natural gas tank 33 increases, and the pressure in the gas phase (BOG) portion rises. When a pressure gauge (not shown) for measuring the pressure in the liquefied natural gas tank is provided in the liquefied natural gas tank 33, and the pressure in the liquefied natural gas tank 33 is higher than a predetermined threshold (for example, 1.1 bar), control is performed to liquefy natural gas. The vaporized gas in the liquefied natural gas tank 33 may be received in the buffer tank 12.
(實施例1) (Example 1)
使用實施形態3之蒸發氣體再冷凝裝置3，藉由模擬而證實儲藏含有甲烷80重量%與氮20重量%之液化天然氣作為原料之情形時之各部中之壓力(barA)、溫度(℃)、流量(kg/h)、甲烷濃度(重量%)及氮濃度(重量 %)。冷媒使用液態氮。 Using the evaporated gas recondensing device 3 of the third embodiment, the pressure (barA), temperature (° C.) in each portion when storing liquefied natural gas containing 80% by weight of methane and 20% by weight of nitrogen as a raw material was confirmed by simulation. Flow rate (kg/h), methane concentration (% by weight) and nitrogen concentration (weight) %). The refrigerant uses liquid nitrogen.
(結果) (result)
若自液化天然氣槽對液化天然氣緩衝槽12以11,740kg/h之流量供給液化天然氣之蒸發氣體(-150℃，1.2barA)，則圖5中之各部A~F、a~e之壓力(barA)、溫度(℃)、流量(kg/h)、甲烷濃度(重量%)及氮濃度(重量%)獲得表1所示之結果。 If the liquefied natural gas tank supplies the liquefied natural gas evaporating gas (-150 ° C, 1.2 bar A) to the liquefied natural gas buffer tank 12 at a flow rate of 11,740 kg / h, the pressure of each part A ~ F, a ~ e in Figure 5 (barA The temperature (°C), the flow rate (kg/h), the methane concentration (% by weight), and the nitrogen concentration (% by weight) were obtained as shown in Table 1.
圖5中之各部A~F係測定蒸發氣體之溫度等之部位，圖5中之各部a~e係測定冷媒氮之溫度等之部位。圖5中之各部A~F、a~e之位置如下所述。 In each of the parts A to F in Fig. 5, the temperature of the evaporating gas is measured, and the parts a to e in Fig. 5 are measured at the temperature of the refrigerant nitrogen or the like. The positions of the respective parts A to F and a to e in Fig. 5 are as follows.
A之位置為來自液化天然氣槽(未圖示)之蒸發氣體即將導入至液化天然氣緩衝槽12之前。A之位置中之測定結果與蒸發氣體導出配管11中之部位(圖5中之(A)所示)之測定結果同等。 The position of A is that the vaporized gas from the liquefied natural gas tank (not shown) is to be introduced before the liquefied natural gas buffer tank 12. The measurement result in the position of A is equivalent to the measurement result of the portion (shown as (A) in Fig. 5) in the evaporated gas discharge pipe 11.
B之位置處於第一氣體供給部114，為第一冷凝器111與第二冷凝器211之間。 The position of B is in the first gas supply unit 114 and is between the first condenser 111 and the second condenser 211.
C之位置處於第一返送配管113，為第一冷凝器111與液化天然氣緩衝槽12之間。 The position of C is in the first return pipe 113 between the first condenser 111 and the liquefied natural gas buffer tank 12.
D之位置處於第二排氣配管214，為第二冷凝器211之上部出口部分。 The position of D is in the second exhaust pipe 214, which is the upper outlet portion of the second condenser 211.
E之位置處於第二返送配管213，為第二冷凝器211與液化天然氣緩衝槽12之間。 The position of E is between the second return pipe 213 and the second condenser 211 and the liquefied natural gas buffer tank 12.
F之位置為液化天然氣緩衝槽12之底部出口部分，為液化天然氣緩衝槽12與液化天然氣槽(未圖示)之間。 The position of F is the bottom outlet portion of the liquefied natural gas buffer tank 12, which is between the liquefied natural gas buffer tank 12 and the liquefied natural gas tank (not shown).
a之位置為即將使冷媒之液態氮導入至冷媒緩衝槽13之前，為配置於冷媒緩衝槽13之前段之壓力調整器22與冷媒緩衝槽13之間。 The position of a is between the pressure regulator 22 and the refrigerant buffer tank 13 disposed before the refrigerant buffer tank 13 just before the liquid nitrogen of the refrigerant is introduced into the refrigerant buffer tank 13.
b之位置處於第二冷媒返送流路215，為冷媒緩衝槽13與第二熱交換部212 之間。 The position of b is in the second refrigerant return flow path 215, which is the refrigerant buffer tank 13 and the second heat exchange portion 212. between.
c之位置處於第二冷媒送出流路216，為第二熱交換部212與第一冷媒流量調整閥21之間。 The position of c is in the second refrigerant delivery flow path 216 between the second heat exchange unit 212 and the first refrigerant flow rate adjustment valve 21.
d之位置處於第一冷媒返送流路115，為冷媒緩衝槽13與第一熱交換部112之間。 The position of d is in the first refrigerant return flow path 115, and is between the refrigerant buffer groove 13 and the first heat exchange portion 112.
e之位置為第一熱交換部112之出口部分。 The position of e is the exit portion of the first heat exchange portion 112.
根據實施例1之結果，於第一冷凝器111及第二冷凝器211之任一者中均不會使甲烷凝固，可將液化天然氣之蒸發氣體再冷凝。液化天然氣中之氮濃度於已自液化天然氣槽導入至液化天然氣緩衝槽12時為20.0重量%，相對於此，於已自第二冷凝器211返送至液化天然氣緩衝槽12時，氮濃度為20.6重量%(圖5中之E)。因此，甲烷之凝固點於不包含氮之情形時為-182℃，相對於此，於包含20.6重量%之氮之情形時降低至-186℃。因此，即便冷卻至-182℃而甲烷亦不會凝固，可以液體狀態返送至液化天然氣緩衝槽12。 According to the result of Example 1, methane is not solidified in either of the first condenser 111 and the second condenser 211, and the vaporized gas of the liquefied natural gas can be recondensed. The nitrogen concentration in the liquefied natural gas is 20.0% by weight when it is introduced into the liquefied natural gas buffer tank 12 from the liquefied natural gas tank. In contrast, when the nitrogen concentration has been returned from the second condenser 211 to the liquefied natural gas buffer tank 12, the nitrogen concentration is 20.6. % by weight (E in Figure 5). Therefore, the freezing point of methane is -182 ° C in the case where nitrogen is not contained, whereas it is lowered to -186 ° C in the case of containing 0.26% by weight of nitrogen. Therefore, even if it is cooled to -182 ° C, methane does not solidify, and it can be returned to the liquefied natural gas buffer tank 12 in a liquid state.
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| CN104913593B (en) * | 2015-05-15 | 2018-07-24 | 新地能源工程技术有限公司 | A kind of liquefied technique of BOG and device |
| CN204678802U (en) * | 2015-05-15 | 2015-09-30 | 新地能源工程技术有限公司 | The device that a kind of rich nitrogen BOG liquefies |
| CN205090722U (en) * | 2015-10-26 | 2016-03-16 | 成都华气厚普机电设备股份有限公司 | Marine BOG of LNG is liquefying plant again |
| CN105486031A (en) * | 2016-01-07 | 2016-04-13 | 惠生（南通）重工有限公司 | Natural gas liquefying system used for FLNG (floating liquefied natural gas) and liquefying method thereof |
| CN105758113A (en) * | 2016-03-04 | 2016-07-13 | 浙江大学常州工业技术研究院 | Fluctuating inlet heat exchange system and fluctuating inlet heat exchange method |
| CN106122756A (en) * | 2016-08-16 | 2016-11-16 | 中科赛德（北京）科技有限公司 | A kind of liquefied natural gas tank car reclaiming BOG |
| WO2018096187A2 (en) * | 2017-02-14 | 2018-05-31 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Lng production system equipped with recondenser |
| CN210374297U (en) * | 2019-06-21 | 2020-04-21 | 武汉市燃气热力规划设计院有限公司 | BOG cold energy utilization system for natural gas liquefaction storage base |
-
2018
- 2018-06-08 TW TW107119866A patent/TWI712769B/en active
- 2018-06-08 TW TW107207727U patent/TWM572423U/en unknown
- 2018-10-05 JP JP2018189601A patent/JP7228983B2/en active Active
- 2018-11-06 CN CN201880071430.9A patent/CN111344528B/en active Active
- 2018-11-06 WO PCT/EP2018/080252 patent/WO2019101502A1/en active Application Filing
- 2018-11-06 KR KR1020207016115A patent/KR20200090798A/en not_active Application Discontinuation
- 2018-11-06 SG SG11202003922UA patent/SG11202003922UA/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| CN111344528B (en) | 2022-02-01 |
| KR20200090798A (en) | 2020-07-29 |
| JP2019095055A (en) | 2019-06-20 |
| SG11202003922UA (en) | 2020-06-29 |
| JP7228983B2 (en) | 2023-02-27 |
| TWI712769B (en) | 2020-12-11 |
| TWM572423U (en) | 2019-01-01 |
| CN111344528A (en) | 2020-06-26 |
| WO2019101502A1 (en) | 2019-05-31 |
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