KR101675879B1 - Device and method for re-liquefying BOG - Google Patents

Device and method for re-liquefying BOG Download PDF

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Publication number
KR101675879B1
KR101675879B1 KR1020150097087A KR20150097087A KR101675879B1 KR 101675879 B1 KR101675879 B1 KR 101675879B1 KR 1020150097087 A KR1020150097087 A KR 1020150097087A KR 20150097087 A KR20150097087 A KR 20150097087A KR 101675879 B1 KR101675879 B1 KR 101675879B1
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South Korea
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gas
supplied
stage compressor
evaporation
evaporation gas
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KR1020150097087A
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Korean (ko)
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신현준
문영식
최동규
안수경
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대우조선해양 주식회사
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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
    • F17C5/00—Methods or apparatus for filling containers with liquefied, solidified, or compressed gases under pressures
    • F17C5/02—Methods or apparatus for filling containers with liquefied, solidified, or compressed gases under pressures for filling with liquefied gases
    • 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
    • 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
    • F17C7/00—Methods or apparatus for discharging liquefied, solidified, or compressed gases from pressure vessels, not covered by another subclass
    • F17C7/02—Discharging liquefied gases
    • F17C7/04—Discharging liquefied gases 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
    • 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
    • F17C2227/00—Transfer of fluids, i.e. method or means for transferring the fluid; Heat exchange with the fluid
    • F17C2227/01—Propulsion of the fluid
    • F17C2227/0128—Propulsion of the fluid with pumps or compressors
    • F17C2227/0171—Arrangement
    • F17C2227/0185—Arrangement comprising several pumps or compressors
    • 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
    • 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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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Ocean & Marine Engineering (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)

Abstract

Disclosed is an evaporation gas re-liquefaction apparatus and method.
According to the present invention, it is possible to reduce the consumption of energy required for liquefying the evaporation gas while achieving the original purpose of re-liquefying the evaporation gas in the evaporation gas remelting apparatus.
In addition, when the present invention is applied to a floating suspension using liquefied gas as a fuel, the liquefied gas can be vaporized and supplied to an engine without using a separate vaporizer, thereby simplifying the facility of the floating suspension.
According to an aspect of the present invention, there is provided an apparatus for liquefying a vaporized gas, the apparatus comprising: a tank in which liquefied gas is stored; Heat exchange means provided downstream of the tank; A multi-stage compressor provided downstream of the heat exchange unit and compressing a part of the evaporated gas discharged from the heat exchange unit; A first expansion means which is provided downstream of the heat exchange means and which decompresses a part of the evaporation gas that has passed through the multi-stage compressor and the heat exchange means to cool it to generate a gas-liquid mixture; And a gas-liquid separator provided downstream of the first expansion means and separating the gas-liquid mixture discharged from the first expansion means into a liquid; Wherein the multi-stage compressor includes a plurality of compressors provided in series, and the heat exchange means exchanges heat between the evaporation gas supplied from the tank and the gas-liquid separator and the evaporation gas supplied from the multi-stage compressor, And the remaining evaporation gas excluding the amount of the cooled evaporated gas that is supplied to the first expansion means through the multi-stage compressor and the heat exchange means is supplied to the plurality of compression sections of the multi-stage compressor And is supplied to any one of the downstream side.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a device and method for re-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for re-liquefying an evaporation gas, and more particularly, to an apparatus and a method for re-liquefying an evaporation gas by recovering cold and heat of the evaporation gas.

In the case of transporting a gas containing a hydrocarbon as a main component through the sea, it is necessary to liquefy the gas because it becomes too bulky when it is transported in a gaseous state.

In order to prevent the liquefied gas from evaporating due to heat exchange with the outside, various kinds of heat insulating structures are provided in the tank for storing the liquefied gas in the liquefied gas transportation line for transporting the liquefied gas.

However, since it is impossible to completely insulate from the outside, the evaporation of the liquefied gas is constantly generated in the tank storing the liquefied gas, and the liquefied gas thus evaporated is called the boil off gas. When the evaporation gas accumulates in the tank, the pressure inside the tank increases and the generation of the evaporation gas is further accelerated. Therefore, it is necessary to discharge the evaporation gas to the outside or re-liquefy and return to the tank again.

As a method of liquefying the evaporation gas, there is a method of liquefying the evaporation gas by transferring cold heat to the evaporation gas by using a separate refrigerant such as nitrogen, a method of recovering the cold heat of the evaporation gas without re- . Particularly, the method of recovering the cold heat of the evaporation gas without the separate refrigerant to re-liquefy the evaporation gas can reduce the equipment for liquefaction of the evaporation gas and can save the energy consumption required for liquefaction of the evaporation gas .

Nevertheless, even in the method of re-liquefying the evaporation gas by using the cold of the evaporation gas, it is still required to energize the compressor to compress the evaporation gas in order to liquefy the evaporation gas. Therefore, it is necessary to reduce the energy supplied to the compressor or the like for evaporative gas compression in the evaporative gas re-liquefaction facility.

Accordingly, it is an object of the present invention to provide an evaporation gas remelting apparatus and method which attains the original purpose of re-liquefying the evaporation gas while reducing the consumption of energy required for re-liquefaction of the evaporation gas.

According to an aspect of the present invention, there is provided an apparatus for liquefying a vaporized gas, the apparatus comprising: a tank in which liquefied gas is stored; Heat exchange means provided downstream of the tank; A multi-stage compressor disposed downstream of the heat exchange unit and compressing the evaporated gas discharged from the heat exchange unit; A first expansion means which is provided downstream of the heat exchange means and which decompresses a part of the evaporation gas that has passed through the multi-stage compressor and the heat exchange means to cool it to generate a gas-liquid mixture; And a gas-liquid separator provided downstream of the first expansion means and separating the gas-liquid mixture discharged from the first expansion means into a liquid; Wherein the multi-stage compressor includes a plurality of compressors provided in series, and the heat exchange means exchanges heat between the evaporation gas supplied from the tank and the gas-liquid separator and the evaporation gas supplied from the multi-stage compressor, And the remaining evaporation gas excluding the amount of the cooled evaporated gas that is supplied to the first expansion means through the multi-stage compressor and the heat exchange means is supplied to the plurality of compression sections of the multi-stage compressor There is provided an evaporation gas remelting device which is supplied to any one of the downstream.

The heat exchanging unit exchanges heat between the evaporating gas discharged from the tank and the evaporating gas discharged from the gas-liquid separator with the evaporating gas discharged from the multi-stage compressor to cool the evaporating gas discharged from the multi-stage compressor. An intermediate cooler for further cooling the evaporated gas supplied through the multi-stage compressor and the heat recovery unit; And a second expansion means provided between the heat recovery unit and the intercooler to reduce the pressure of a part of the evaporation gas supplied to the intercooler to cool the intercooler; And an evaporator which is supplied to the intermediate cooler without being supplied to the second expansion means among the evaporation gas cooled by the second expansion means and the evaporative gas supplied to the intermediate cooler among the evaporated gases supplied to the intermediate cooler, Gas can be heat-exchanged in the intermediate cooler.

The heat exchange unit may include a multi-stream heat exchanger; And a third expansion means provided upstream of the multi-stream heat exchanger; The multi-stream heat exchanger heat-exchanges the evaporated gas discharged from the tank and the evaporated gas discharged from the gas-liquid separator with the evaporated gas discharged from the multi-stage compressor to cool the evaporated gas discharged from the multi-stage compressor , Some of the evaporated gas passing through the multi-stage compressor and the multi-stream heat exchanger is cooled through the third expansion means, and then supplied to the multi-stream heat exchanger again, so that the evaporated gas discharged from the multi-stage compressor can be cooled by heat exchange .

The multi-stage compressor may be a four-stage compressor.

The evaporation gas other than the amount of evaporation gas that has passed through the multi-stage compressor and the heat exchange means, supplied to the first expansion means, may be supplied downstream of the first-stage compression section of the multi-stage compressor.

The pressure of the evaporation gas supplied downstream of the first-stage compressing portion may be 2 to 5 bar.

A vaporizer provided between the heat exchange means and the first expansion means for vaporizing the liquefied gas by exchanging heat between the evaporation gas supplied from the heat exchange means to the first expansion means and the liquefied gas supplied through another path; And a fuel supply source supplied with the liquefied gas vaporized in the vaporizer; As shown in FIG.

The liquefied gas supplied through the other path may be any one of ethane, ethylene, propylene, and LPG.

The evaporation gas may be any one of ethane, ethylene, propylene, and LPG.

According to another aspect of the present invention, there is provided a method of liquefying a vaporized gas in a vessel for transporting liquefied gas, the method comprising: a four-stage compressor for compressing the evaporated gas discharged from a tank storing a liquefied gas; And the evaporation gas discharged after being compressed by the four-stage compressor is cooled by heat exchange with evaporation gas discharged from the tank, and then a part or all of the refrigerant is supplied to the downstream of the first- Is provided.

According to the present invention, it is possible to reduce the consumption of energy required for liquefying the evaporation gas while achieving the original purpose of re-liquefying the evaporation gas in the evaporation gas remelting apparatus.

In addition, when the present invention is applied to a floating suspension using liquefied gas as a fuel, the liquefied gas can be vaporized and supplied to an engine without using a separate vaporizer, thereby simplifying the facility of the floating suspension.

1 is a configuration diagram of an evaporation gas remelting apparatus according to a first embodiment of the present invention.
2 is a configuration diagram of an evaporation gas remelting apparatus according to a second embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention will be described with reference to the embodiments shown in the drawings, but it is to be understood that various modifications and equivalent embodiments may be made by those skilled in the art without departing from the scope of the present invention. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

1 is a configuration diagram of an evaporation gas remelting apparatus according to a first embodiment of the present invention.

As used herein, the 'evaporative gas' may be any one of ethane, ethylene, propylene, and LPG.

As shown in FIG. 1, the apparatus for liquefying vaporized gas according to the first embodiment of the present invention comprises a tank 1 for storing a liquefied gas and discharging evaporated gas generated from the liquefied gas, A compressor 10 for compressing the gas, and a heat exchanging means 100 provided between the tank 1 and the compressor 10. In the heat exchange means (100), the evaporation gas discharged from the tank (1) and the evaporation gas discharged from the compressor (10) heat exchange and the evaporation gas discharged from the compressor (10) is cooled. The compressor 10 may be a multi-stage compressor or a four-stage compressor. When the compressor 10 is a four-stage compressor, the compressor 10 includes a first compression section 12, a second compression section 14, a third compression section 16, And a fourth compression unit (18). Downstream of the first to fourth compression units 12, 14, 16, and 18, a cooler 20 for intermediate cooling the evaporation gas may be provided.

The pressure of the evaporation gas downstream of the first compression section 12 may be 2 to 5 bar, for example 3.5 bar and the pressure of the evaporation gas downstream of the second compression section 14 may be 10 to 15 bar, for example 12 bar. Further, the pressure of the evaporation gas downstream of the third compression section 16 may be 25 to 35 bar, for example, 30.5 bar, the pressure of the evaporation gas downstream of the fourth compression section 18 may be 75 to 90 bar, For example, 83.5 bar.

Downstream of the heat exchange means 100 are a first expansion means 30 for decompressing and cooling a part of the evaporation gas which has passed through the compressor 10 and the heat exchange means 100 to generate a vapor-liquid mixture from the evaporation gas, And a gas-liquid separator (40) provided downstream of the expansion means (30) for separating the gas-liquid mixture into a gas and a liquid. The liquid in the liquid discharged from the gas-liquid separator 40 returns to the tank 1 and the gas joins the evaporated gas discharged from the tank 1 through the re-supply line L4 and is returned to the heat exchanging means 100 .

The tank 1, the compressor 10, the heat exchanging means 100, the first expansion means 30 and the gas-liquid separator 40 are arranged in such a manner that the evaporation gas discharged from the tank 1 is re- Liquefying line L1 that provides a path to return to the first liquefaction line L1.

In the apparatus for liquefying vaporized gas according to the first embodiment of the present invention, the heat exchanging means 100 exchanges heat between the evaporated gas discharged from the tank 1 and the evaporated gas discharged from the compressor 10, An intermediate cooler 112 provided downstream of the heat recovery unit 110 and supplied with the evaporated gas cooled by the heat recovery unit 110, a heat recovery unit 110 disposed downstream of the heat recovery unit 110, And a second expansion device (not shown) provided between the recovery unit 110 and the intercooler 112 for decompressing and cooling some of the evaporation gas supplied from the heat recovery unit 110 to the intercooler 112 and supplying the decompressed gas to the intercooler 112 (114). That is, some of the evaporated gas supplied from the heat recovery unit 110 to the intercooler 112 passes through the second expansion means 114 provided on the bypass line L2 and the remainder passes through the re-liquefaction line L1 To the intercooler 112. [0050]

On the other hand, the evaporated gas that has passed through the second expansion means 114 and the intermediate cooler 112 flows into the compressor 10. At this time, when the compressor 10 is a multi-stage compressor, the evaporation gas that has passed through the second expansion means 114 and the intercooler 112 passes through the compressor supply line L3, And is supplied to any one of them downstream. At this time, if the compressor 10 is a four-stage compressor, the evaporation gas may be supplied to the first compression section 12, or downstream of the second compression section 14.

1, when the evaporation gas re-liquefying apparatus according to the first embodiment of the present invention is installed in a floating suspended body using liquefied gas as fuel, it is preferable that an inter-cooler 112 and a first expansion means 30 A vaporizer 50 may be provided. The vaporizer 50 is configured to vaporize and supply the liquefied gas from the fuel tank 3 storing the liquefied gas as fuel to the fuel consumer 2 such as an engine. At this time, the evaporation gas supplied from the intercooler 112 to the first expansion means 30 along the re-liquefaction line L1 is supplied from the vaporizer 50 to the fuel consumer 2 from the fuel tank 3, So as to vaporize the liquefied gas supplied from the fuel tank 3 to the fuel consumer 2.

The fuel supplied from the fuel tank 3 to the vaporizer 50 may be selected from the group consisting of ethane, ethylene, propylene, and LPG (Liquefied Petroleum Gas). Therefore, when there are a plurality of fuel tanks 3, the types of fuel stored in the respective fuel tanks 3 may be all the same or may be different from each other. Also, the types of fuel stored in some tanks of the fuel tank 3 may be the same, and the fuel stored in the remaining tanks may be different.

Hereinafter, the operation of the evaporation gas remelting apparatus according to the first embodiment of the present invention will be described with reference to FIG.

The evaporated gas discharged from the tank 1 passes through the heat recovery unit 110 and is supplied to the compressor 10 and compressed. The evaporated gas compressed and discharged in the compressor (10) is again supplied to the heat recovery unit (110). In the heat recovery unit 110, the evaporated gas discharged from the compressor 10 is exchanged with the evaporated gas discharged from the tank 1 and supplied to the heat recovery unit 110, and the evaporated gas discharged from the compressor 10 is cooled . At this time, the pressure of the evaporation gas discharged from the compressor 10 may be 40 to 100 bar, and the temperature of the evaporation gas cooled by the heat recovery unit 110 as the evaporation gas discharged from the compressor 10 may be in the range of -10 to + Lt; / RTI >

Some of the evaporated gas cooled and discharged in the heat recovery unit 110 is supplied to the second expansion means 114 provided on the bypass line L2, is reduced in pressure and cooled and then supplied to the intercooler 112, And the remainder is directly supplied to the intercooler 112 via the refueling line L1. At this time, heat exchange occurs in the intermediate cooler 112. That is, the evaporation gas supplied to the intercooler 112 through the second expansion means 114 provided on the bypass line L2 is supplied to the intercooler 112 through the re-liquefaction line L1 Thereby cooling the evaporated gas. The evaporated gas passing through the second expansion means 114 and the intercooler 112 is supplied to the compressor 10 through the compressor supply line L3.

On the other hand, the evaporated gas cooled in the intercooler 112 is heat-exchanged with the liquefied gas supplied from the fuel tank 3 to the fuel consumer 2 as described above in the vaporizer 50 via the refueling line L1, The liquefied gas supplied from the tank 3 to the fuel consumer 2 is vaporized. Thereafter, the evaporation gas is supplied to the first expansion means (30) and is depressurized and cooled. Through this process, the evaporation gas becomes a gas-liquid mixture. The gas-liquid mixture thus produced is supplied to the gas-liquid separator 40 and is separated into gas and liquid. The liquid returns to the tank 1 and the gas joins the evaporative gas supplied from the tank 1 to the heat recovery unit 110 through the re-supply line L4, and then repeats the above-described process.

2 is a configuration diagram of an evaporation gas remelting apparatus according to a second embodiment of the present invention.

1 and the reference numerals shown in Fig. 2 are the same. Therefore, the difference from FIG. 1 will be mainly described.

2, the apparatus for liquefying vaporized gas according to the second embodiment of the present invention includes a multi-stream heat exchanger (not shown) provided between a tank 1 and a compressor 10 as heat exchange means 100 120), and a third expansion means (122) provided upstream of the multi-stream heat exchanger (120).

1, the pressure of the evaporation gas downstream of the first compression section 12 may be 2 to 5 bar, for example, 3.5 bar, and the pressure of the evaporation gas downstream of the second compression section 14 may be 10 to 20 bar, 15 bar, for example 12 bar. Further, the pressure of the evaporation gas downstream of the third compression section 16 may be 25 to 35 bar, for example, 30.5 bar, the pressure of the evaporation gas downstream of the fourth compression section 18 may be 75 to 90 bar, For example, 83.5 bar.

Similarly, the fuel tank 3 may be plural, and the fuel supplied from the fuel tank 3 to the vaporizer 50 may be selected from the group consisting of ethane, ethylene, propylene, and LPG (Liquefied Petroleum Gas). Therefore, when there are a plurality of fuel tanks 3, the types of fuel stored in the respective fuel tanks 3 may be all the same or may be different from each other. Also, the types of fuel stored in some tanks of the fuel tank 3 may be the same, and the fuel stored in the remaining tanks may be different.

Hereinafter, the operation of the evaporative gas remelting apparatus according to the second embodiment of the present invention will be described with reference to FIG. 2, focusing on differences from the first embodiment of the present invention shown in FIG.

The evaporated gas supplied from the tank 1 to the compressor 10 through the multi-stream heat exchanger 120, compressed, and then discharged is supplied to the multi-stream heat exchanger 120 again. Primary heat exchange occurs in the multi-stream heat exchanger (120). That is, the evaporated gas discharged from the tank 1 and supplied to the multi-stream heat exchanger 120 and the evaporated gas supplied from the compressor 10 are heat-exchanged, and the evaporated gas supplied from the compressor 10 is cooled. This is because the evaporated gas discharged from the tank 1 is at a cryogenic temperature close to the boiling point while the evaporated gas supplied from the compressor 10 is heated at a relatively high temperature due to compression in the compressor 10.

A part of the evaporated gas cooled in the multi-stream heat exchanger 120 passes through the vaporizer 50, the first expansion means 30 and the gas-liquid separator 40, and performs the same process as the first embodiment of the present invention described above It goes through. The remaining evaporation gas excluding the amount of evaporated gas cooled in the multi-stream heat exchanger 120, which is supplied to the evaporator 50, is supplied to the third expansion means 122, decompressed and cooled, 120. At this time, in the multi-stream heat exchanger 120, secondary heat exchange occurs. That is, since the evaporated gas supplied to the multi-stream heat exchanger 120 through the third expansion means 122 is relatively low in temperature, the refrigerant is heat-exchanged with the evaporated gas supplied from the compressor 10 to the multi-stream heat exchanger 120, (10) to the multi-stream heat exchanger (120).

That is, the evaporated gas discharged from the compressor 10 and supplied to the multi-stream heat exchanger 120 is cooled (a) by evaporation gas discharged from the tank 1 and supplied to the multi-stream heat exchanger 120 (B) is cooled (secondary heat exchange) by the evaporation gas decompressed and cooled by the third expansion means 122.

The temperature of the evaporation gas supplied to the multi-stream heat exchanger 120 after passing through the third expansion means 122 is lower than the temperature of the evaporation gas discharged from the tank 1 and supplied to the multi-stream heat exchanger 120 The evaporated gas discharged from the compressor 10 and supplied to the multi-stream heat exchanger 120 for efficient cooling in the multi-stream heat exchanger 120 can be cooled by sequentially performing the primary heat exchange and the secondary heat exchange. have.

1 - tank
2 - Fuel Demand Side
3 - Fuel tank
10 - Multistage compressor
12 - first compression section
14 - the second compression section
16 - the third compression section
18 - fourth compression section
20 - Cooler
30 - first expansion means
40 - gas-liquid separator
50 - Vaporizer
100 - heat exchange means
110 - Heat recovery unit
112 - Intermediate cooler
114 - a second expansion means
120 - Multi-stream heat exchanger
122 - a third expansion means
L1 - Re-liquefaction line
L2 - Bypass line
L3 - compressor supply line
L4 - Re-supply line

Claims (10)

An evaporation gas remelting device provided in a ship for transporting liquefied gas,
A tank in which liquefied gas is stored;
Heat exchange means provided downstream of the tank;
A multi-stage compressor disposed downstream of the heat exchange unit and compressing the evaporated gas discharged from the heat exchange unit;
A first expansion means which is provided downstream of the heat exchange means and which decompresses a part of the evaporation gas that has passed through the multi-stage compressor and the heat exchange means to cool it to generate a gas-liquid mixture; And
A gas-liquid separator provided downstream of the first expansion means and separating the gas-liquid mixture discharged from the first expansion means into gas and liquid; / RTI >
Wherein the multi-stage compressor includes a plurality of compressors provided in series,
The heat exchange means exchanges heat between the evaporation gas supplied from the tank and the gas-liquid separator and the evaporation gas supplied from the multi-stage compressor, thereby cooling the evaporation gas supplied from the multi-stage compressor,
Stage compressing unit, and the remaining evaporation gas excluding the amount of the evaporated gas cooled through the multi-stage compressor and the heat exchanging unit, supplied to the first expansion unit, is supplied downstream of any one of the plurality of compression units of the multi-
Evaporating gas remelting device. The method according to claim 1,
The heat exchanging means
A heat recovery unit for heat-exchanging the evaporated gas discharged from the tank and the evaporated gas discharged from the gas-liquid separator with the evaporated gas discharged from the multi-stage compressor to cool the evaporated gas discharged from the multi-stage compressor;
An intermediate cooler for further cooling the evaporated gas supplied through the multi-stage compressor and the heat recovery unit; And
A second expansion means provided between the heat recovery unit and the intercooler to decompress and cool part of the evaporation gas supplied to the intercooler; / RTI >
The evaporation gas supplied to the intermediate cooler is supplied to the intermediate cooler without being supplied to the second expansion means among the evaporation gas cooled by the second expansion means and the evaporative gas supplied to the intermediate cooler among the evaporated gases supplied to the intermediate cooler, Heat exchanger in the cooler,
Evaporating gas remelting device. The method according to claim 1,
The heat exchanging unit includes:
Multi-stream heat exchanger; And
A third expansion means provided upstream of the multi-stream heat exchanger; / RTI >
In the multi-stream heat exchanger,
Stage compressor, the evaporation gas discharged from the tank and the evaporation gas discharged from the gas-liquid separator are exchanged with the evaporation gas discharged from the multi-stage compressor to cool the evaporation gas discharged from the multi-stage compressor,
Wherein a part of the evaporated gas passing through the multi-stage compressor and the multi-stream heat exchanger is cooled through the third expansion means and then supplied to the multi-stream heat exchanger again to cool the evaporated gas discharged from the multi-
Evaporating gas remelting device. The method according to claim 1,
Wherein the multi-stage compressor is a four-stage compressor,
Evaporating gas remelting device. The method of claim 4,
Stage compressing unit of the multi-stage compressor, and the remaining evaporation gas excluding the amount of the evaporation gas that has passed through the multi-stage compressor and the heat exchanging unit, supplied to the first expansion unit,
Evaporating gas remelting device. The method of claim 5,
Wherein the pressure of the evaporation gas supplied downstream of the first-stage compressing portion is 2 to 5 bar,
Evaporating gas remelting device. The method according to claim 1,
A vaporizer provided between the heat exchange means and the first expansion means for vaporizing the liquefied gas by exchanging heat between the evaporation gas supplied from the heat exchange means to the first expansion means and the liquefied gas supplied through another path; And
A fuel consumer that receives the liquefied gas vaporized in the vaporizer; ≪ / RTI >
Evaporating gas remelting device. The method of claim 7,
Wherein the liquefied gas supplied through the other path is any one of ethane, ethylene, propylene, and LPG,
Evaporating gas remelting device. The method according to claim 1,
Wherein the evaporation gas is any one of ethane, ethylene, propylene, and LPG,
Evaporating gas remelting device. A method for re-liquefying a vaporized gas in a vessel for transporting liquefied gas,
The evaporation gas discharged from the tank storing the liquefied gas is supplied to a multi-stage compressor for compressing,
Cooling the compressed evaporated gas with the evaporated gas discharged from the tank,
At least a part of the cooled evaporated gas is branched and decompressed,
The cooled evaporated gas is further cooled with the decompressed evaporated gas,
The further cooled evaporation gas is decompressed and cooled to form a gas-liquid mixture,
The gas-liquid mixture is subjected to gas-liquid separation to supply cold gas of the separated gas to the compressed evaporative gas,
Wherein the reduced-pressure evaporation gas further cooled by the evaporation gas is supplied downstream of any one of the plurality of compression sections of the multi-stage compressor.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190064784A (en) * 2017-12-01 2019-06-11 대우조선해양 주식회사 Fuel Gas Supply System and Method for a Ship
KR20220043277A (en) 2020-09-29 2022-04-05 (주)테크니컬코리아 Boil-off gas reliquefaction apparatus
KR102499137B1 (en) 2021-08-11 2023-02-13 (주)테크니컬코리아 Boil-off gas reliquefaction system

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Publication number Priority date Publication date Assignee Title
KR20150062841A (en) * 2013-11-29 2015-06-08 현대중공업 주식회사 Treatment system of liquefied gas

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
KR20150062841A (en) * 2013-11-29 2015-06-08 현대중공업 주식회사 Treatment system of liquefied gas

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190064784A (en) * 2017-12-01 2019-06-11 대우조선해양 주식회사 Fuel Gas Supply System and Method for a Ship
KR102376276B1 (en) * 2017-12-01 2022-03-18 대우조선해양 주식회사 Fuel Gas Supply System and Method for a Ship
KR20220043277A (en) 2020-09-29 2022-04-05 (주)테크니컬코리아 Boil-off gas reliquefaction apparatus
KR102499137B1 (en) 2021-08-11 2023-02-13 (주)테크니컬코리아 Boil-off gas reliquefaction system

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