KR101805498B1 - Vessel - Google Patents

Abstract

A ship comprising a liquefied gas storage tank is disclosed.
The vessel comprising: a first compressor capable of compressing at least a portion of the evaporative gas discharged from the storage tank; A second compressor for compressing another portion of the evaporative gas discharged from the storage tank; A propulsion compressor for compressing a part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A first heat exchanger for exchanging heat between the evaporated gas compressed by the propulsion compressor and the evaporated gas discharged from the storage tank; A refrigerant pressure reducing device for expanding another part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger that compresses the evaporated gas compressed by the propulsion compressor and heat-exchanged in the first heat exchanger, using the fluid expanded by the refrigerant decompression device as a refrigerant; An additional compressor for compressing the refrigerant having passed through the refrigerant decompressor and the second heat exchanger; And a first decompression device for expanding the fluid cooled in the first heat exchanger and the second heat exchanger after being compressed by the propulsion compressor, wherein the additional compressor further comprises: As shown in Fig.

Description

Ship {Vessel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ship, and more particularly, to a ship including a system for re-liquefying remaining evaporative gas used as fuel of an engine among evaporative gases generated in a storage tank.

In recent years, consumption of liquefied gas such as Liquefied Natural Gas (LNG) has been rapidly increasing worldwide. The liquefied gas obtained by liquefying the gas at a low temperature has an advantage of being able to increase the storage and transport efficiency because the volume becomes very small as compared with the gas. In addition, liquefied natural gas, including liquefied natural gas, can be removed as an eco-friendly fuel with less air pollutant emissions during combustion because air pollutants can be removed or reduced during the liquefaction process.

Liquefied natural gas is a colorless transparent liquid obtained by cooling methane-based natural gas to about -162 ° C and liquefying it, and it has a volume of about 1/600 of that of natural gas. Therefore, when the natural gas is liquefied and transported, it can be transported very efficiently.

However, since the liquefaction temperature of natural gas is a cryogenic temperature of -162 ° C at normal pressure, liquefied natural gas is sensitive to temperature changes and is easily evaporated. As a result, the storage tank storing the liquefied natural gas is subjected to heat insulation, but the external heat is continuously transferred to the storage tank. Therefore, in the transportation of liquefied natural gas, the liquefied natural gas is naturally vaporized continuously in the storage tank, -Off Gas, BOG) occurs. This also applies to other low temperature liquefied gases such as ethane.

Evaporation gas is a kind of loss and is an important issue in transport efficiency. Further, when the evaporation gas accumulates in the storage tank, the internal pressure of the tank may rise excessively, and there is a risk that the tank may be damaged. Accordingly, various methods for treating the evaporative gas generated in the storage tank have been studied. Recently, a method of re-liquefying the evaporated gas and returning it to the storage tank for treating the evaporated gas, a method of returning the evaporated gas to the storage tank And a method of using it as an energy source of a consuming place.

As a method for re-liquefying the evaporation gas, there is a method of re-liquefying the evaporation gas by heat exchange with the refrigerant by providing a refrigeration cycle using a separate refrigerant, and a method of re-liquefying the evaporation gas by using the evaporation gas itself as a refrigerant . Particularly, the system adopting the latter method is called a Partial Re-liquefaction System (PRS).

On the other hand, among the engines used in ships, there are gas fuel engines such as DFDE and ME-GI engines which can use natural gas as fuel.

The DFDE adopts the Otto Cycle, which consists of four strokes, and injects natural gas with a relatively low pressure of about 6.5 bar into the combustion air inlet, compressing the piston as it rises.

The ME-GI engine consists of two strokes and employs a diesel cycle in which high pressure natural gas at around 300 bar is injected directly into the combustion chamber at the top of the piston. In recent years, there is a growing interest in ME-GI engines with better fuel efficiency and propulsion efficiency.

An object of the present invention is to provide a ship including a system capable of exhibiting enhanced evaporative gas re-liquefaction performance as compared with a conventional partial liquefaction system.

According to an aspect of the present invention, there is provided a ship including a liquefied gas storage tank, comprising: a first compressor capable of compressing at least a part of evaporative gas discharged from the storage tank; A second compressor for compressing another portion of the evaporative gas discharged from the storage tank; A propulsion compressor for compressing a part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A first heat exchanger for exchanging heat between the evaporated gas compressed by the propulsion compressor and the evaporated gas discharged from the storage tank; A refrigerant pressure reducing device for expanding another part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger that compresses the evaporated gas compressed by the propulsion compressor and heat-exchanged in the first heat exchanger, using the fluid expanded by the refrigerant decompression device as a refrigerant; An additional compressor for compressing the refrigerant having passed through the refrigerant decompressor and the second heat exchanger; And a first decompression device for expanding the fluid cooled in the first heat exchanger and the second heat exchanger after being compressed by the propulsion compressor, wherein the additional compressor further comprises: The ship being driven by a power to drive the ship.

The propulsion compressor compresses only the evaporated gas compressed by the first compressor, and the refrigerant depressurizing device may expand only the evaporated gas compressed by the second compressor.

The additional compressor can compress the refrigerant that has passed through the second heat exchanger and send it to the second compressor.

The additional compressor may compress the refrigerant that has passed through the second heat exchanger and direct it to the first compressor and the second compressor.

Wherein the propulsion compressor compresses a portion of the evaporated gas compressed by the first compressor and the second compressor and the refrigerant depressurizing device expands another portion of the evaporated gas compressed by the first compressor and the second compressor, .

The evaporated gas sent to the second heat exchanger passes through the second heat exchanger firstly, is expanded by the refrigerant depressurizing device, and then sent to the second heat exchanger. After being expanded by the refrigerant depressurizing device, Wherein the fluid used as the refrigerant in the first heat exchanger is a fluid sent to the second heat exchanger before passing through the refrigerant decompression device; And the evaporation gas cooled by the first heat exchanger after being compressed by the propulsion compressor.

The ship is further provided with a gas-liquid separator which separates the partially re-liquefied liquefied gas passing through the propulsion compressor, the first heat exchanger, the second heat exchanger and the first decompression device and the evaporated gas remaining in the gaseous state And the liquefied gas separated by the gas-liquid separator is sent to the storage tank, and the evaporated gas separated by the gas-liquid separator can be sent to the first heat exchanger.

A portion of the evaporative gas sent to the propulsion compressor can be diverted upstream of the propulsion compressor and fed to the fuel consumer.

The vessel may form a closed loop refrigerant cycle in which evaporated gas circulates through the second compressor, the refrigerant depressurization device, the second heat exchanger, and the additional compressor.

According to another aspect of the present invention, there is provided a ship including a liquefied gas storage tank, comprising: a first compressor capable of compressing at least a part of evaporative gas discharged from the storage tank; A second compressor for compressing another portion of the evaporative gas discharged from the storage tank; A propulsion compressor for compressing a part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A refrigerant pressure reducing device for expanding another part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A second heat exchanger that uses the fluid expanded by the refrigerant pressure reducing device as a refrigerant to cool the evaporated gas compressed by the propelling compressor; An additional compressor for compressing the refrigerant having passed through the refrigerant decompressor and the second heat exchanger; And a first decompression device for expanding the fluid cooled in the second heat exchanger after being compressed by the propulsion compressor, wherein the additional compressor is driven by a power generated by expanding the fluid in the refrigerant decompression device , Ships are provided.

According to another aspect of the present invention, there is provided an evaporative gas processing system for a ship including a storage tank for storing a liquefied gas, wherein a part of the evaporative gas discharged from the storage tank is supplied by a first compressor A first supply line for compressing and then sending the fuel to a fuel consumer; A second supply line that branches from the first supply line and compresses another part of the evaporated gas discharged from the storage tank by a second compressor; A return line branched from the first supply line, further compressing the compressed evaporated gas by a propulsion compressor, and then passing through the first heat exchanger, the second heat exchanger, and the first decompressor to re- A recirculation line for passing the cooled evaporated gas through the second heat exchanger and the refrigerant decompression device to the second heat exchanger so as to be used as a refrigerant; And an additional compressor installed upstream of the second compressor for compressing the evaporation gas, wherein the additional compressor is driven by a power produced by expanding the fluid of the refrigerant decompression device, and the first heat exchanger is a compressor And the second heat exchanger is configured to cool the evaporation gas passing through the refrigerant decompression device by using the evaporation gas discharged from the tank as a refrigerant, Evaporation gas supplied as a refrigerant along the recycle line; And an evaporation gas supplied along the return line are cooled by heat exchange with each other.

The additional compressor may be installed on the second supply line.

The additional compressor may be installed on the recirculation line downstream of the refrigerant depressurization device and the second heat exchanger.

The evaporative gas treatment system of the ship may include a first additional line connecting between a recirculation line downstream of the refrigerant depressurization device and the second heat exchanger and a second supply line upstream of the second compressor.

The evaporative gas treatment system of the ship is characterized in that the evaporative gas passes through the first additional line after passing through the additional compressor, the second compressor, the second heat exchanger, the refrigerant decompression device and again the second heat exchanger And again to the additional compressor, to form a closed loop refrigerant cycle.

The evaporated gas compressed by the first compressor and the evaporated gas compressed by the second compressor are combined so that a part is re-liquefied along the return line and the other part is re-liquefied along the return line and the second heat exchanger, After passing through the refrigerant decompression apparatus and the second heat exchanger, the refrigerant is discharged from the storage tank, merged with the fluid passing through the first heat exchanger, and the remaining part can be supplied to the fuel consumer.

Wherein some of the evaporated gas compressed by the first compressor is re-liquefied along the return line and the remaining part is supplied to the fuel consumer, and the evaporated gas compressed by the second compressor flows along the recycle line After passing through the second heat exchanger, the refrigerant pressure reducing device, and again the second heat exchanger, the refrigerant can be merged with the fluid discharged from the storage tank and passed through the first heat exchanger.

The ship's evaporative gas treatment system forms a closed loop refrigerant cycle in which evaporative gas circulates through the second compressor, the second heat exchanger, the refrigerant depressurization device, the second heat exchanger, and the additional compressor again can do.

The ship's evaporative gas treatment system further comprising: a second additional line branching from the recycle line downstream of the further compressor and connected to the first supply line upstream of the first compressor; A third addition line branching from a first supply line downstream of the first compressor and connected to a recirculation line upstream of the refrigerant decompressor and the second heat exchanger; And a fourth additional line that branches from a second supply line downstream of the second compressor and is connected to the return line upstream of the propulsion compressor.

The evaporative gas treatment system of the ship is characterized in that after the evaporation gas is compressed by the second compressor, the second heat exchanger, the refrigerant depressurization device, the second heat exchanger and the further compressor And is again supplied back to the second compressor to form a closed loop refrigerant cycle.

Wherein the evaporation gas treatment system of the ship is supplied to the second heat exchanger along the third additional line and the recirculation line after the evaporation gas is compressed by the first compressor, A heat exchanger, and the additional compressor, and back to the first compressor along the second additional line.

According to another aspect of the present invention, there is provided a method for controlling a flow rate of a refrigerant in a liquefied gas storage tank, the method comprising: dividing an evaporated gas discharged from a liquefied gas storage tank into two, 2 compressor, the evaporated gas compressed by the first compressor is further compressed by a propulsion compressor, and then re-liquefied and returned to the storage tank, and the evaporated gas compressed by the second compressor is cooled by a refrigerant cycle Wherein the refrigerant is circulated to cool the evaporated gas compressed by the first compressor, and the fluid circulating the refrigerant cycle is compressed by the additional compressor and then supplied to the second compressor.

Compared with the existing partial liquefaction system (PRS), the present invention is capable of increasing the liquefaction efficiency and the liquefaction amount because the evaporation gas is reduced in pressure after being further cooled by the second heat exchanger. In particular, it is economical to re-cure most or all of the remaining evaporated gas without using a refrigeration cycle using a separate refrigerant.

Further, according to the present invention, it is possible to flexibly control the refrigerant flow rate and the cooling / heating supply according to the engine load depending on the discharge amount of the evaporation gas and the operating speed of the ship.

According to the embodiment of the present invention, since the re-liquefaction efficiency and the amount of liquefaction are increased by using the existing extra compressor, it contributes to securing the space inside the ship and further reduces the cost for installing the compressor . Particularly, not only the evaporation gas compressed by the extra compressor but also the evaporation gas compressed by the main compressor can be used as the refrigerant in the second heat exchanger, thereby increasing the flow rate of the evaporation gas used as the refrigerant in the second heat exchanger It is possible to further increase the liquefaction efficiency and the liquefaction amount.

According to another embodiment of the present invention, since the mass of the fluid used as the refrigerant in the second heat exchanger after being compressed by the second compressor is larger, the efficiency of re-liquefaction in the second heat exchanger and the amount of re- And the power produced by the refrigerant decompression device can be utilized.

In addition, the present invention further includes a propelling compressor, so that the pressure of the evaporative gas passing through the re-liquefaction process can be increased, so that the re-liquefaction efficiency and the amount of liquefaction can be further increased.

1 is a schematic view showing a conventional partial remelting system.
FIG. 2 is a schematic view showing a system for processing an evaporative gas of a ship according to a first embodiment of the present invention.
FIG. 3 is a schematic view showing a system for processing an evaporative gas of a ship according to a second embodiment of the present invention.
4 is a schematic view showing a system for processing an evaporative gas of a ship according to a third embodiment of the present invention.
5 is a schematic view showing a system for processing an evaporative gas of a ship according to a fourth embodiment of the present invention.
FIG. 6 is a schematic view showing a system for processing an evaporative gas of a ship according to a fifth embodiment of the present invention.
FIG. 7 is a schematic view showing a system for processing an evaporative gas of a ship according to a sixth embodiment of the present invention.
8 is a graph schematically illustrating the phase change of methane with temperature and pressure.
9 is a graph showing the temperature values of methane according to the heat flow rate under different pressures, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The ship of the present invention can be applied to various applications such as a ship equipped with an engine using natural gas as fuel and a ship including a liquefied gas storage tank. In addition, the following examples can be modified in various forms, and the scope of the present invention is not limited to the following examples.

Systems for the treatment of the evaporative gas to be described below of the present invention include all types of ships and marine structures, such as liquefied natural gas carriers, liquefied ethane gas carriers, and the like, with storage tanks capable of storing low temperature liquid cargo or liquefied gas, It can be applied to marine structures such as LNG FPSO and LNG FSRU as well as ships such as LNG RV. However, in the following embodiments, liquefied natural gas, which is a typical low temperature liquid cargo, will be described as an example for convenience of explanation.

The fluid in each line of the present invention may be in any one of a liquid state, a gas-liquid mixed state, a gas state, and a supercritical fluid state, depending on operating conditions of the system.

1 is a schematic view showing a conventional partial remelting system.

Referring to FIG. 1, in the conventional partial remanufacturing system, the evaporated gas generated and discharged from the storage tank storing the liquid cargo is conveyed along the pipe and compressed by the evaporated gas compression unit 10.

The storage tank (T) has sealing and thermal barrier to store liquefied gas such as liquefied natural gas at a cryogenic temperature, but it can not completely block the heat transmitted from the outside, and the evaporation of the liquefied gas is continuous And the tank internal pressure can be raised. In order to prevent excessive increase of the tank pressure due to the evaporated gas and to maintain an appropriate level of internal pressure, the evaporated gas inside the storage tank is discharged to the evaporated gas compression unit 10 Supply.

When the evaporated gas discharged from the storage tank and compressed by the evaporation gas compression unit 10 is referred to as a first stream, the first stream of the compressed evaporative gas is divided into the second stream and the third stream, and the second stream is liquefied To the storage tank T, and the third stream may be configured to be supplied to a gas fuel consuming destination such as a propulsion engine or a power generation engine onboard the ship. In this case, in the evaporation gas compression unit 10, the evaporation gas can be compressed to the supply pressure of the fuel consumption source, and the second stream can be branched through all or a part of the evaporation gas compression unit if necessary. All of the evaporated gas compressed in the third stream may be supplied according to the amount of fuel required by the fuel consumption point, or the entire amount of the compressed evaporated gas may be returned to the storage tank. Gas fuel consumption may include a high pressure gas injection engine (e.g., ME-GI engine developed by MDT) and a low pressure gas injection engine (e.g., Wartsila X-DF engine ), DF Generator, gas turbine, DFDE, and the like.

At this time, the heat exchanger 20 is installed to liquefy the second stream of the compressed evaporated gas, and the evaporated gas generated in the storage tank is used as a cold heat source of the compressed evaporated gas. The compressed evaporated gas, that is, the second stream, which has risen in temperature during the compression process in the evaporated gas compressor, is cooled while passing through the heat exchanger 20, and the evaporated gas generated in the storage tank and introduced into the heat exchanger 20 is heated And is supplied to the evaporation gas compression unit 10.

Since the flow rate of the evaporated gas before compression is greater than the flow rate of the second stream, the second stream of compressed evaporated gas may be at least partially liquefied by receiving cold heat from the evaporated gas before being compressed. Thus, in the heat exchanger, the low-temperature evaporation gas immediately after being discharged from the storage tank is heat-exchanged with the high-pressure evaporation gas compressed by the evaporation gas compression unit to liquefy the high-pressure evaporation gas.

The evaporated gas of the second stream passing through the heat exchanger 20 is further cooled while being decompressed while passing through the expansion means 30 such as an expansion valve or an expander and is supplied to the gas-liquid separator 40. The liquid component, that is, the liquefied natural gas, is returned to the storage tank, and the gaseous component, that is, the evaporation gas is discharged from the storage tank to be separated from the heat exchanger 20 and the evaporation gas Is utilized as a cold / hot supply source that joins the evaporation gas flow to the evaporation gas flow supplied to the compression section (10) or is supplied to the heat exchanger (20) again to heat the evaporation gas in the high pressure state compressed by the evaporation gas compression section . Of course, it may be sent to a gas combustion unit (GCU) or the like, or it may be consumed by sending it to a gas consumption source (including a gas engine). Further expansion means (50) for further depressurizing the gas separated in the gas-liquid separator before joining the evaporative gas stream may be further provided.

FIG. 2 is a schematic view showing a system for processing an evaporative gas of a ship according to a first embodiment of the present invention.

Referring to FIG. 2, the system of the present embodiment is characterized in that a refrigerant circulation unit 300a which is supplied with boil off gas generated from low-temperature liquid refrigerant stored in a storage tank and circulates the evaporated gas to the refrigerant is formed .

And a refrigerant supply line (CSLa) for supplying evaporation gas from the storage tank to the refrigerant circulation part (300a). The valve (400a) is provided in the refrigerant supply line, and a sufficient amount of evaporation gas The refrigerant supply line CSLa is cut off and the refrigerant circulation unit 300a is operated as a closed loop.

As in the above-described basic embodiment, the first expanded embodiment also includes the first compressor 100a that compresses the evaporative gas generated from the low-temperature liquid cargo in the storage tank T. The evaporated gas generated in the storage tank is introduced into the first compressor 100a along the evaporation gas supply line BLa.

The storage tank (T) of the present embodiment is made of an independent type tank in which the load of the liquid cargo is not directly applied to the heat insulating layer, or a membrane type tank in which the load of the cargo is directly applied to the heat insulating layer . In the case of an independent tank type tank, it is also possible to use it as a pressure vessel designed to withstand a pressure of 2 barg or more.

However, the evaporated gas compressed by the first compressor 100a may be supplied to the fuel consuming area including the propulsion engine of the ship or the marine structure and the engine for power generation, And there may be no evaporative gas to be re-liquefied when the fuel consumption amount can consume the entire amount of the evaporated gas. When the consumption of the gaseous fuel is low or absent, such as when the ship is anchored, the entire amount of the evaporated gas may be supplied to the re-liquefaction line RLa.

The compressed evaporated gas is supplied to the first heat exchanger 200a along the evaporation gas re-liquefaction line RLa. The first heat exchanger 200a is connected to the evaporation gas re-liquefaction line RLa and the evaporation gas supply line BLa, So as to heat exchange the evaporated gas to be introduced into the first compressor 100a and the compressed evaporated gas through at least a part of the first compressor 100a. The evaporated gas whose temperature has increased in the compression process is cooled through heat exchange with the low temperature evaporated gas which is generated in the storage tank and is to be introduced into the first compressor 100a.

The second heat exchanger 500a is provided downstream of the first heat exchanger 200a and the evaporated gas heat-exchanged in the first heat exchanger 200a after the compression is heat-exchanged with the evaporative gas circulating in the refrigerant circulation unit 300a And further cooled.

The refrigerant circulation unit 300a includes a refrigerant compressor 310a for compressing the evaporation gas supplied from the storage tank, a first cooler 320a for cooling the evaporated gas compressed in the refrigerant compressor, And a refrigerant decompression device 330a for decompressing and further cooling the cooled evaporated gas. The refrigerant decompressor 330a may be an expansion valve or an expander for cooling the evaporation gas by thermally expanding the gas.

The evaporated gas cooled through the refrigerant decompressor 330a is supplied to the second heat exchanger 500a as a refrigerant along the refrigerant circulation line CCLa to be supplied to the first heat exchanger 200a in the second heat exchanger 500a Thereby cooling the evaporated gas through heat exchange with the supplied evaporated gas. The evaporated gas of the refrigerant circulation line (CCLa) through the second heat exchanger (500a) is circulated to the refrigerant compressor (310a), and circulates through the refrigerant circulation line through the above-described compression and cooling process.

Meanwhile, the evaporation gas of the evaporation gas re-liquefaction line (RLa) cooled by the second heat exchanger (500a) is decompressed through the first decompressor (600a). The first decompressor 600a may be an expansion valve, such as a Joule-Thomson valve, or an expander.

Liquid separated from the gas-liquid separator 700a, that is, the liquefied natural gas, is supplied to the storage tank T, and the liquid stored in the gas-liquid separator 700a is supplied to the gas-liquid separator 700a downstream of the first decompressor 600a Restored.

The gas separated from the gas-liquid separator 700a, that is, the evaporated gas is further depressurized via the second decompressor 800a, and the evaporated gas is introduced into the first heat exchanger 200a from the storage tank T, It may be utilized as a cold heat source that joins the gas flow or is again supplied to the first heat exchanger 200a to heat-exchange the compressed high-pressure evaporated gas in the first compressor 100a. Of course, it may be sent to a gas combustion unit (GCU) or the like, or it may be consumed by sending it to a fuel demanding place (including a gas engine).

FIG. 3 is a schematic view showing a system for processing an evaporative gas of a ship according to a second embodiment of the present invention.

3, the present embodiment differs from the first embodiment in that the evaporation gas to be introduced from the first cooler 320b to the refrigerant decompressor 330b in the refrigerant circulating unit 300b is subjected to heat exchange with the decompressed gas in the refrigerant decompressor 330b And then supplied to the refrigerant pressure-reducing device 330b.

Since the evaporation gas is cooled while being decompressed through the refrigerant decompressor 330b, the temperature of the evaporation gas downstream of the refrigerant decompression device is lower than the temperature of the evaporation gas upstream of the refrigerant decompression device. In this embodiment, Is cooled by heat exchange with the downstream evaporation gas, and then introduced into the decompression apparatus. 3, the second heat exchanger 500b can supply evaporative gas upstream of the refrigerant decompressor 330b (part A of FIG. 3). A separate heat exchanger capable of exchanging heat with the evaporation gas upstream and downstream of the refrigerant decompressor may be additionally provided.

As described above, the system of the present embodiments can re-liquefy and store the evaporated gas generated from the storage tank liquid cargo, thereby increasing the transportation rate of the liquid cargo. In particular, even when the consumption of fuel on the in-ship gas consumer is low, the amount of wasted cargo can be reduced or eliminated by burning in a gas combustion unit (GCU) in order to prevent the pressure rise of the storage tank, .

In addition, since the evaporation gas is circulated through the refrigerant and utilized as a heat source for re-liquefying the evaporated gas, the evaporated gas can be effectively re-liquefied without constructing a separate refrigerant cycle, and it is not necessary to supply a separate refrigerant. It contributes to secure space and is economical. In addition, if the refrigerant in the refrigerant cycle is insufficient, the refrigerant can be replenished from the storage tank to smoothly replenish the refrigerant, and the refrigerant cycle can be effectively operated.

In this way, the evaporation gas can be re-liquefied by using the cold and hot of the evaporation gas itself in multiple steps, and the system configuration for treating the evaporation gas on board can be simplified, and the cost required for installing and operating the apparatus for complicated evaporation gas processing Can be saved.

4 is a schematic view showing a system for processing an evaporative gas of a ship according to a third embodiment of the present invention.

Referring to FIG. 4, the ship of this embodiment includes a first heat exchanger 110 installed downstream of the storage tank T; A first compressor (120) and a second compressor (122) installed downstream of the first heat exchanger (110) and compressing the evaporated gas discharged from the storage tank (T); A first cooler 130 for lowering the temperature of the evaporated gas compressed by the first compressor 120; A second cooler 132 for lowering the temperature of the evaporated gas compressed by the second compressor 122; A first valve (191) installed upstream of the first compressor (120); A second valve 192 installed downstream of the first cooler 130; A third valve (193) installed upstream of the second compressor (122); A fourth valve 194 installed downstream of the second cooler 132; A second heat exchanger (140) for further cooling the evaporated gas cooled by the first heat exchanger (110); A refrigerant decompression device 160 that expands the evaporated gas that has passed through the second heat exchanger 140 and then sends it to the second heat exchanger 140; And a first decompression device (150) for expanding the evaporated gas further cooled by the second heat exchanger (140).

The evaporated gas, which is naturally generated in the storage tank T and then discharged, is supplied to the fuel consumer 180 along the first supply line L1. The first heat exchanger (110) is installed in the first supply line (L1) to recover cold and heat from the evaporated gas immediately after being discharged from the storage tank (T). The ship of the present embodiment may further include an eleventh valve (203) installed upstream of the fuel demanding place (180) for controlling the flow rate and opening and closing of the evaporating gas sent to the fuel demanding place (180).

The first heat exchanger 110 is used as a refrigerant to cool the evaporation gas supplied to the first heat exchanger 110 along the return line L3 by receiving the evaporation gas discharged from the storage tank T. [ On the return line L3, a fifth valve 195 for regulating the flow rate and opening / closing of the evaporation gas may be installed.

The first compressor (120) and the second compressor (122) compress the evaporated gas that has passed through the first heat exchanger (110). The first compressor 120 is installed on the first supply line L1 and the second compressor 122 is installed on the second supply line L2. The second supply line L2 is branched from the first supply line L1 upstream of the first compressor 120 and connected to the first supply line L1 downstream of the first compressor 120. [ Also, the first compressor 120 and the second compressor 122 may be installed in parallel and may be compressors having the same performance.

Generally, a second compressor (122) and a second cooler (132) are additionally provided to the ship in case the first compressor (120) and the first cooler (130) fail. Conventionally, the second compressor 122 and the second cooler 132 are not used in a normal state in which the first compressor 120 or the first cooler 130 fails.

That is, conventionally, when the first compressor 120 or the first cooler 130 fails, the third valve 193 upstream of the second compressor 122 and the fourth valve 193 downstream of the second cooler 132, The valve 194 is closed so that the evaporated gas passes through the first compressor 120 and the first cooler 130 to be supplied to the fuel consumer 180 and the first compressor 120 or the first cooler 130 The third valve 193 upstream of the second compressor 122 and the fourth valve 194 downstream of the second cooler 132 are opened and the first valve 191 upstream of the first compressor 120 is opened, And the second valve 192 downstream of the first cooler 130 are closed to allow the evaporated gas to pass through the second compressor 122 and the second cooler 132 to be supplied to the fuel consumer 180.

The present invention is for increasing the liquefaction efficiency and re-liquefaction capacity of the evaporative gas using the second compressor (122) and the second cooler (132) And the other part is used as a refrigerant for additionally cooling the evaporation gas in the second heat exchanger 140. The second heat exchanger 140 is provided in the second heat exchanger 140,

8 is a graph schematically illustrating the phase change of methane with temperature and pressure. Referring to FIG. 8, methane enters a supercritical fluid state at a temperature of approximately -80 占 폚 or higher and a pressure of approximately 55 bar or higher. That is, in the case of methane, the critical point is about -80 ° C, 55 bar. The supercritical fluid state is a third state different from the liquid state or gas state.

On the other hand, if the temperature is lower than the critical point at a pressure higher than the critical point, the state of the supercritical fluid may be similar to that of the supercritical fluid, which is different from the general liquid state. , Hereinafter referred to as "high pressure liquid state ".

The evaporated gas compressed by the first compressor 120 or the second compressor 122 may be in a gaseous state or in a supercritical fluid state depending on the degree of compression.

When the evaporated gas sent to the first heat exchanger 110 through the return line L3 is in a gaseous state, the evaporated gas passes through the first heat exchanger 110 and the temperature is lowered to become a mixed state of the liquid and the gas And in the supercritical fluid state, the temperature can be lowered through the first heat exchanger 110 to become "high-pressure liquid state ".

The temperature of the evaporated gas cooled by the first heat exchanger 110 is lowered as it passes through the second heat exchanger 140. When the evaporated gas passing through the first heat exchanger 110 is mixed with the liquid and the gas State, the evaporated gas passes through the second heat exchanger 140 and becomes lower in temperature and becomes a mixed state or a liquid state in which the ratio of the liquid becomes higher. In the case of the "high pressure liquid state ", the second heat exchanger The temperature is lowered while passing through the heat exchanger 140.

Also, even when the evaporated gas that has passed through the second heat exchanger 140 is in the "high-pressure liquid state ", the evaporated gas passes through the first decompressor 150 and becomes low in pressure, .

Even if the evaporation gas is lowered to the same degree (P in FIG. 8) by the first decompression device 150, the temperature is lower than that in the case where the temperature is higher (Y - > Y 'in Fig. 8), the ratio of the liquid becomes higher. In addition, if the temperature can be lowered, the evaporation gas can theoretically be 100% re-liquefied (Z → Z 'in FIG. 8). Therefore, if the evaporated gas is further cooled by the second heat exchanger 140 before passing through the first decompressor 150, the re-liquefaction efficiency and the liquefaction amount can be increased.

Referring to FIG. 4 again, this embodiment is different from the first embodiment and the second embodiment in that refrigerant circulation parts 300a and 300b for further cooling the evaporation gas are constituted by a closed loop, Loop configuration.

In the first and second embodiments, the refrigerant circulation units 300a and 300b are constituted by closed loops, and the evaporated gas compressed by the refrigerant compressors 310a and 310b flows through the second heat exchangers 500a and 500b, And can not be sent to the fuel consumer, nor can it go through the liquefaction process.

On the other hand, in the present embodiment, the refrigerant cycle is configured as an open loop so that the evaporated gas compressed by the second compressor 122 is merged with the evaporated gas compressed by the first compressor 120, A part of the refrigerant is sent to the fuel consumer 180 and the other part is used as the refrigerant in the second heat exchanger 140 along the recycle line L5 and the remaining part is subjected to the liquefaction process along the return line L3.

The recycle line L5 is a line branched from the first supply line L1 downstream of the first compressor 120 and connected to the first supply line L1 upstream of the first compressor 120. [ A sixth valve 196 for regulating the flow rate and opening and closing of the evaporation gas may be installed on the recycle line L5 where the evaporated gas branched from the first supply line L1 is sent to the second heat exchanger 140 .

The present embodiment in which the refrigerant cycle is formed as an open loop is different from the first and second embodiments in which the refrigerant cycle is constituted by a closed loop and the downstream line of the first compressor 120 and the downstream line of the second compressor 122 are connected There is a big difference. That is, in this embodiment, the second supply line L 2 downstream of the second compressor 122 is connected to the first supply line L 1 downstream of the first compressor 120, The compressed evaporated gas is combined with the evaporated gas compressed by the first compressor 120 and then sent to the second heat exchanger 140, the fuel consumer 180, or the first heat exchanger 110. The present embodiment includes all other modifications in which the downstream line of the first compressor 120 and the downstream line of the second compressor 122 are connected.

Therefore, according to the present embodiment, when the demanded amount at the fuel demanding place 180 increases, for example, the ship's operating speed increases, not only the evaporated gas compressed by the first compressor 120 but also the evaporated gas compressed by the second compressor 122, Can also be sent to the fuel consumer.

Generally, however, since the first compressor 120 and the second compressor 122 are designed to have a capacity approximately 1.2 times the amount required in the fuel consumer 180, the capacity of the first compressor 120 is exceeded And the evaporated gas compressed by the second compressor 122 is not required to be sent to the fuel demanding unit 180. Rather, if the evaporated gas discharged from the storage tank T can not be consumed by the fuel consumer 180 and the evaporative gas to be re-liquefied increases, a large amount of refrigerant is required to re-liquefy a large amount of evaporated gas More frequent.

According to the present embodiment, not only the evaporated gas compressed by the first compressor 120 but also the evaporated gas compressed by the second compressor 122 can be used as the refrigerant for heat exchange in the second heat exchanger 140 The evaporated gas supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 can be cooled to a lower temperature by using more refrigerant, Liquefaction efficiency and liquefaction amount can be increased, and theoretically, 100% liquefaction is possible.

Generally, when determining the capacities of the compressors 120 and 122 installed on the ship, the capacity required for supplying the evaporative gas to the fuel consumer station 180 and the evaporative gas remaining not consumed in the fuel consumer station 180 are re- However, according to the present embodiment, since the amount of liquefaction can be increased by using the second compressor 122, the capacity required for re-liquefaction can be reduced, and a small capacity compressor 120 , 122 can be installed. Reducing the capacity of the compressor has the advantage of saving both equipment installation and operating costs.

In this embodiment, the first valve 191 and the second valve 192 as well as the third valve 193 and the fourth valve 193, as well as the first valve 191 and the second valve 192, The valve 194 is also opened to energize both the first compressor 120, the first cooler 130, the second compressor 122 and the second cooler 132 so that the first compressor 120 or the first cooler 132, The first valve 191 and the second valve 192 are closed and the second compressor 122 and the second cooler 132 are closed by closing the first valve 191 and the second valve 192. In this case, The system is operated only by the evaporated gas that has passed through the evaporator.

The first compressor 120 and the first cooler 130 serve as a main part and the second compressor 122 and the second cooler 132 serve as an auxiliary part. The compressor (120) and the second compressor (122), the first cooler (130) and the second cooler (132) have the same role, and two or more compressors and coolers It satisfies the concept of redundancy in that one can be replaced by another if it fails. Hereinafter, the same applies.

Therefore, even when the second compressor 122 or the second cooler 132 fails, the re-liquefaction efficiency and the amount of liquefaction can be increased as well as the case where the first compressor 120 or the first cooler 130 fails The third valve 193 and the fourth valve 194 are closed and the system is operated only by the evaporated gas that has passed through the first compressor 120 and the first cooler 130.

On the other hand, when the ship is operated at a high speed such that most or all of the evaporative gas discharged from the storage tank T can be used as fuel for the fuel consumer 180, the amount of the evaporative gas to be re- Or disappear. Accordingly, when the ship is operated at a high speed, either the first compressor 120 or the second compressor 122 may be driven.

The first compressor 120 and the second compressor 122 can compress the evaporation gas at a pressure required by the fuel consumer 180. The fuel consumer 180 can be an engine, have. For example, when the fuel consumer 180 is an engine for propelling a ship, the first compressor 120 and the second compressor 122 can compress the evaporation gas to a pressure of approximately 10 to 100 bar.

The first compressor 120 and the second compressor 122 can compress the evaporation gas to a pressure of approximately 150 bar to 400 bar when the fuel consumer 180 is an ME-GI engine, Is DFDE, the evaporation gas can be compressed to a pressure of approximately 6.5 bar, and if the fuel consumer 180 is an X-DF engine, the evaporation gas can be compressed to a pressure of approximately 16 bar.

The first compressor 120 and the second compressor 122 may include a plurality of different types of engines such as X, DF, and DFDE. In the case where the fuel demanding unit 180 includes the X-DF engine and the DFDE, - DFDE compresses the vapor to the required pressure and DFDE is installed upstream of the DFDE to reduce the pressure of the compressed vapor to the pressure required by the X-DF engine. .

In addition, in order to increase the liquefaction efficiency and the liquefaction amount in the first heat exchanger 110 and the second heat exchanger 140, the first compressor 120 or the second compressor 122 may be operated to supply the evaporation gas The evaporation gas is compressed so that the pressure exceeds the pressure demanded by the fuel consumer 180 and a decompression device is installed upstream of the fuel consumer 180 so that the pressure of the compressed evaporated gas The pressure may be supplied to the fuel demanding place 180 after lowering the pressure to a pressure required by the fuel demanding place 180. [

Meanwhile, the first compressor 120 and the second compressor 122 may be multi-stage compressors, respectively. 4 shows that the first compressor 120 and the second compressor 122 compress the evaporated gas to a pressure required by the fuel consumer 180 by one compressor 120 or 122, The evaporation gas can be compressed several times by the plurality of compression cylinders to the pressure required by the fuel consumer 180. [

When the first compressor 120 and the second compressor 122 are multi-stage compressors, a plurality of compression cylinders may be installed in series in the first compressor 120 and the second compressor 122, And a plurality of coolers may be installed downstream thereof, respectively.

The first cooler 130 of the present embodiment is installed downstream of the first compressor 120 and is cooled by the first compressor 120 to cool not only the pressure but also the temperature of the evaporated gas, (132) is installed downstream of the second compressor (122), and is compressed by the second compressor (122) to cool not only the pressure but also the temperature of the evaporated gas. The first cooler 130 and the second cooler 132 can cool the evaporated gas through heat exchange with seawater, fresh water, or air introduced from the outside.

The second heat exchanger 140 of this embodiment further cools the evaporation gas supplied to the second heat exchanger 140 along the return line L3 after being cooled by the first heat exchanger 110, Exemplary refrigerant pressure reducing device 160 inflates the evaporated gas that has passed through the second heat exchanger 140, and then sends it to the second heat exchanger 140 again.

That is, the second heat exchanger 140 supplies the evaporated gas supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 to the refrigerant pressure-reducing device 160 Exchanges the evaporated gas expanded by the refrigerant with the refrigerant, and further cools it.

The refrigerant pressure reducing device 160 of this embodiment may be various means for lowering the pressure of the fluid. The state of the fluid just before passing through the refrigerant depressurization device 160 and the state of the fluid just after passing through the refrigerant pressure- Can vary. However, when the refrigerant pressure-reducing device 160 is an inflator, in order to prevent physical damage to the refrigerant pressure-reducing device 160, the fluid just before passing through the refrigerant pressure-reducing device 160 and the fluid just after passing through the refrigerant pressure- . Hereinafter, the same applies.

The evaporation gas used as the refrigerant for the heat exchange in the second heat exchanger 140 after passing through the refrigerant decompression device 160 is compressed by the second compressor 122 by the second compressor 122, A part of the combined vaporized gas is supplied to the second heat exchanger 140 along the recycle line L5 and the refrigerant passed through the refrigerant decompressor 160 in the second heat exchanger 140 Exchanged with the refrigerant and then supplied to the refrigerant decompressor 160. [0064]

The evaporated gas supplied from the first supply line L1 to the second heat exchanger 140 along the recycle line L5 is primarily cooled by the second heat exchanger 140 and supplied to the refrigerant decompressor 160 And then sent back to the second heat exchanger 140 to be used as a refrigerant.

That is, the evaporated gas compressed by the first compressor 120 is merged with the evaporated gas compressed by the second compressor 122, and then supplied to the second heat exchanger 140 along the recycle line L5; And the evaporation gas supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 are both supplied to the refrigerant decompressor 160 through the refrigerant decompressor 160, And is cooled by heat exchange.

The first decompression device 150 of the present embodiment is installed on the return line L3 to expand the evaporation gas cooled by the first heat exchanger 110 and the second heat exchanger 140. [ The evaporated gas compressed by the first compressor (120) is combined with the evaporated gas compressed by the second compressor (122) and then partially branched, and flows along the return line (L3) to the first heat exchanger 2 heat exchanger 140 and the first decompressor 150 to partially or totally re-liquefy.

The first decompression device 150 includes all means capable of expanding and cooling the evaporation gas, and may be an expansion valve, such as a Joule-Thomson valve, or an expander.

The vessel of the present embodiment has a gas-liquid separator 170 installed on a return line L3 downstream of the first decompressor 150 and separating the gas-liquid mixture discharged from the first decompressor 150 into gas and liquid .

When the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or the gas-liquid mixed vaporized gas that has passed through the first decompressor 150 is directly sent to the storage tank T.

When the vessel of the present embodiment includes the gas-liquid separator 170, the vaporized gas that has passed through the first decompressor 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3 and the gas separated by the gas-liquid separator 170 flows from the gas-liquid separator 170 to the first heat exchanger 110 to the first heat exchanger 110 along a gas discharge line L4 extending to the first supply line L1 upstream of the first heat exchanger 110. [

A seventh valve 197 for regulating the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank T when the ship of this embodiment includes the gas-liquid separator 170; And an eighth valve (198) for controlling the flow rate of the gas separated by the gas-liquid separator (170) and sent to the first heat exchanger (110).

(191, 192, 193, 194, 195, 196, 197, 198, 203) of the first to eighth valves and the eleventh valve of this embodiment can be manually adjusted And may be automatically adjusted to be opened or closed by a preset value.

The main flow of the evaporating gas is defined to facilitate the operation of the apparatus for evaporating gas re-liquefaction according to an embodiment of the present invention. The flow of the evaporated gas generated in the storage tank T and the gas discharged from the gas-liquid separator 170 is supplied to the first heat exchanger 110 in the first flow 100, the first heat exchanger 110, The flow that is discharged from the first compressor 120 or the second compressor 122 after being supplied to the compressor 120 or the second compressor 122 and supplied to the fuel consumer 180 is referred to as a second flow 102, The flow branched from the second flow 102 to the second heat exchanger 140 downstream of the compressor 120 and the second compressor 122 is referred to as the third flow 104, the first compressor 120, The flow branching from the second flow 102 downstream of the compressor 122 and supplied to the first heat exchanger 110 is referred to as the fourth flow 106 and the flow from the first heat exchanger 110 to the second heat exchanger 140 The supplied flow is defined as the fifth flow 108. The first stream 100 passes through the first heat exchanger 110 and becomes the second stream 102 while the fourth stream 106 passes through the first heat exchanger 110 and the fifth stream 108 do.

Hereinafter, the operation of the apparatus for evaporating gas re-liquefaction according to an embodiment of the present invention will be described with reference to FIG.

The gaseous evaporative gas generated in the storage tank T for storing the liquefied gas in a liquid state is supplied to the first heat exchanger 110. At this time, the gaseous evaporation gas generated in the storage tank T meets the gaseous evaporation gas discharged from the gas-liquid separator 170 after a certain period of time has elapsed from the operation of the system to form the first stream 100 do. Ultimately, the evaporated gas supplied to the first heat exchanger 110 is the first flow 100.

The first heat exchanger 110 collects cold heat of the first flow 100 and cools the other evaporation gas. That is, the first heat exchanger 110 recovers the cold heat of the first stream 100 and supplies it to the first heat exchanger 110 of the second stream 102, that is, (106).

Thus, in the first heat exchanger 110, heat exchange occurs between the first stream 100 and the fourth stream 106 such that the first stream 100 is heated and the fourth stream 106 is cooled. The heated first stream 100 becomes the second stream 102 and the cooled fourth stream 106 becomes the fifth stream 108. [

The second stream 102 discharged from the first heat exchanger 110 is supplied to the first compressor 120 or the second compressor 122 and is supplied to the first compressor 120 or the second compressor 122 by the first compressor 120 or the second compressor 122 Compressed.

The second stream 102, in which the evaporated gas compressed by the first compressor 120 and the evaporated gas compressed by the second compressor 122 are combined, is partly discharged through the second heat exchanger 140 And the other part is supplied to the first heat exchanger 110 as the fourth flow 106 to be cooled and the remaining part is supplied to the fuel consuming place 180. [

The third flow 104 supplied to the second heat exchanger 140 is discharged from the second heat exchanger 140 and expanded in the refrigerant pressure reducing device 160 and then supplied to the second heat exchanger 140. The third stream 104 supplied to the second heat exchanger 140 is supplied to the third heat exchanger 140 after being expanded in the refrigerant decompressor 160 and then supplied to the second heat exchanger 140. [ And cooled. The third stream 104 that has passed through the refrigerant decompressor 160 and the second heat exchanger 140 merges with the second stream 102 discharged from the first heat exchanger 110 and flows through the first compressor 120 ) Or the second compressor (122).

The fourth stream 106 cooled by the heat exchange in the first heat exchanger 110 with the first stream 100 becomes the fifth stream 108 and is supplied to the second heat exchanger 140. The fifth stream 108 supplied to the second heat exchanger 140 is cooled by heat exchange with the third stream 104 that has passed through the refrigerant depressurizing device 160 and then passes through the first pressure reducing device 150 Is expanded. The fifth stream 108, which has passed through the first decompression device 150, becomes a vapor-liquid mixture state in which gas and liquid are mixed.

The fifth stream 108 in the vapor-liquid mixture state is immediately sent to the storage tank T or separated into gas and liquid as it passes through the gas-liquid separator 170. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T. The gas separated by the gas-liquid separator 170 is supplied again to the first heat exchanger 110 to repeat the above processes.

5 is a schematic view showing a system for processing an evaporative gas of a ship according to a fourth embodiment of the present invention.

The ship of the fourth embodiment shown in Fig. 5 is different from the ship of the third embodiment shown in Fig. 4 in that an additional compressor 124 and an additional cooler 134 installed in the second supply line L2, A tenth valve 202, a twelfth valve 205, and a first additional line (not shown), as well as a propulsion compressor 126 and a propellant cooler 136, L6), and the refrigerant cycle may be operated as a closed loop or an open loop by modifying a part of the line through which the evaporation gas flows, and there is a difference therebetween. Hereinafter, do. The detailed description of the same members as those of the ship of the third embodiment will be omitted.

5, the vessel of the present embodiment includes a first heat exchanger 110, a first valve 191, a first compressor 120, a first cooler 130, a second The first valve 192, the third valve 193, the second compressor 122, the second cooler 132, the fourth valve 194, the second heat exchanger 140, the refrigerant pressure reducing device 160, 1 decompression device 150, as shown in FIG.

The storage tank T of this embodiment stores therein liquefied natural gas such as liquefied natural gas or liquefied ethane gas, and discharges the evaporated gas to the outside when the internal pressure becomes equal to or higher than a predetermined pressure, as in the third embodiment. The evaporated gas discharged from the storage tank (T) is sent to the first heat exchanger (110).

The first heat exchanger 110 of the present embodiment uses the evaporation gas discharged from the storage tank T as the refrigerant and flows along the return line L3 to the first heat exchanger 110 Cool the evaporated gas sent. That is, the first heat exchanger 110 recovers the cold heat of the evaporated gas discharged from the storage tank T and supplies the recovered cold heat to the evaporated gas sent to the first heat exchanger 110 along the return line L3 Supply. On the return line L3, a fifth valve 195 for regulating the flow rate and opening / closing of the evaporation gas may be installed.

The first compressor (120) of this embodiment is provided on the first supply line (L1) to compress the evaporated gas discharged from the storage tank (T) in the same manner as in the third embodiment, 122 are installed in parallel with the first compressor 120 on the second supply line L2 to compress the evaporated gas discharged from the storage tank T as in the third embodiment. The first compressor (120) and the second compressor (122) may be compressors having the same performance, and each may be a multi-stage compressor.

The first compressor 120 and the second compressor 122 of this embodiment can compress the evaporation gas to the pressure required by the fuel demanding place 180 as in the third embodiment. When the fuel demanding unit 180 includes various kinds of engines, the evaporating gas is compressed in accordance with the required pressure of the engine requiring a higher pressure (hereinafter referred to as a "high-pressure engine"), Pressure engine provided downstream of the engine (hereinafter referred to as a " low-pressure engine ") which supplies the engine to the engine and the other part that requires a lower pressure. In addition, in order to increase the re-liquefaction efficiency and the liquefaction amount in the first heat exchanger 110 and the second heat exchanger 140, the evaporation gas is supplied to the first compressor (120) or the second compressor (122) A pressure reducing device is provided upstream of the fuel demanding place 180 and the pressure of the evaporating gas compressed at a high pressure is lowered to a pressure required by the fuel demanding place 180, (180).

The vessel of the present embodiment further includes an eleventh valve 203 provided upstream of the fuel demanding place 180 for controlling the flow rate and opening and closing of the evaporating gas sent to the fuel demanding place 180 .

As in the third embodiment, since the ship of this embodiment uses the evaporated gas compressed by the second compressor 122 as a refrigerant for further cooling the evaporated gas in the second heat exchanger 140, The amount of liquefaction can be increased.

As in the third embodiment, the first cooler 130 of this embodiment is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 and not only the pressure but also the temperature, The second cooler 132 of this embodiment is installed downstream of the second compressor 122 and cools the evaporated gas passing through the second compressor 122 as well as the pressure as well as the temperature, as in the third embodiment.

The second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 in the same manner as the third embodiment and is supplied with the evaporation gas cooled by the first heat exchanger 110 Lt; / RTI >

According to this embodiment, as in the third embodiment, the evaporated gas discharged from the storage tank T is further cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, It is possible to supply the first decompression device 150 with the re-liquefaction efficiency and the liquefaction amount.

The refrigerant pressure reducing device 160 of the present embodiment inflates the evaporation gas that has passed through the second heat exchanger 140 and then sends it to the second heat exchanger 140 as in the third embodiment.

The first decompression device 150 of the present embodiment is provided on the return line L3 in the same manner as the third embodiment and is provided with the evaporation gas cooled by the first heat exchanger 110 and the second heat exchanger 140 Lt; / RTI > The first decompression device 150 of the present embodiment includes all means capable of expanding and cooling the evaporation gas and may be an expansion valve such as a Joule-Thomson valve or an expander.

The vessel of this embodiment is provided on the return line L3 downstream of the first decompressor 150 and separates the gas-liquid mixture discharged from the first decompressor 150 into gas and liquid, as in the third embodiment , And a gas-liquid separator (170).

When the vessel of the present embodiment does not include the gas-liquid separator 170, the liquid or the gas-liquid mixed vaporized gas that has passed through the first decompressor 150 is directly sent to the storage tank T as in the third embodiment When the ship of this embodiment includes the gas-liquid separator 170, the evaporated gas that has passed through the first decompressor 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3 and the gas separated by the gas-liquid separator 170 flows from the gas-liquid separator 170 to the first heat exchanger 110 to the first heat exchanger 110 along a gas discharge line L4 extending to the first supply line L1 upstream of the first heat exchanger 110. [

The seventh valve 197 (hereinafter, referred to as " 197 ") for regulating the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank T as in the third embodiment, ); And an eighth valve (198) for controlling the flow rate of the gas separated by the gas-liquid separator (170) and sent to the first heat exchanger (110).

However, the ship of this embodiment is different from the third embodiment in that the additional compressor 124 installed on the second supply line L2; An additional cooler 134 installed downstream of the additional compressor 124; A propulsion compressor (126) installed on the return line (L3); A propellant cooler 136 installed downstream of the propulsion compressor 126; A first additional line L6 connecting between the recycle line L5 and the second supply line L2; A ninth valve 201 installed on the recirculation line L5; A tenth valve (202) installed on the first additional line (L6); And a twelfth valve (205) installed on the recycle line (L5) between the second supply line (L2) and the second heat exchanger (140).

Also, unlike the third embodiment, which selectively includes the sixth valve, the ship of the present embodiment has a recirculation line (not shown) in which the evaporated gas branched from the first supply line L1 is sent to the second heat exchanger 140 L5) and includes a sixth valve (196) for regulating the flow rate and opening and closing of the evaporation gas.

The additional compressor 124 of the present embodiment may be installed upstream or downstream of the second compressor 122 on the second supply line L2 and may have a smaller capacity than the second compressor 122. [ The additional compressor 124 can be driven by the power generated by the refrigerant pressure reducing device 160 while expanding the fluid and the capacity of the additional compressor 124 is driven by the power generated by the refrigerant pressure reducing device 160 Lt; / RTI > The power generated by the refrigerant pressure-reducing device 160 by the refrigerant pressure-reducing device 160 is used in the additional compressor 124. However, the power generated by the refrigerant pressure-reducing device 160 is supplied to the first compressor 120 ) Or the second compressor (122).

Types of compressors include a Centrifugal Compressor that rotates a wing car at high speed to compress gas with energy by centrifugal force, a Reciprocating Compressor that compresses gas by reciprocating movement of the piston in the cylinder, A reciprocating compressor and a screw compressor belong to a positive displacement compressor which compresses a gas sucked in a certain volume.

It is preferred that the first compressor 120 and the second compressor 122 of the present embodiment are positive displacement compressors and that the additional compressors 124 are centrifugal compressors, The second compressor 122 compresses the same flow rate as that of the first compressor 120 so that the effect that the mass flow rate of the evaporation gas passing through the second supply line L2 is the same and the pressure only becomes high Occurs. However, when the additional compressor 124 is installed upstream of the second compressor 122, the evaporated gas compressed by the additional compressor 124 and having a higher density is supplied to the second compressor 122, It is possible to increase the mass flow rate of the evaporation gas supplied to the evaporator.

That is, when the additional compressor 124 is installed upstream of the second compressor 122, the evaporated gas supplied to the second supply line L2 after being discharged from the storage tank T is compressed by the additional compressor 124 So that the mass of the evaporated gas supplied to the second compressor 122 becomes larger even if the evaporated gas of the same flow rate is supplied to the second compressor 122. As a result, since the mass of the fluid used as the refrigerant in the second heat exchanger 140 after being compressed by the second compressor 122 becomes larger, the re-liquefaction efficiency and the liquefaction amount in the second heat exchanger 140 . In the case where the additional compressor 124 is installed upstream of the second compressor 122, it is possible to operate the present embodiment in a closed loop and in an independent open loop, as well as to control the outlet pressure of the second compressor 122 to the first compressor 120) and may be operated in an open loop.

Further, when the additional compressor 124 is installed downstream of the second compressor 122, the mass flow rate is determined by the capacity of the second compressor 122, and the additional compressor 124 only serves to increase the additional pressure . It is also preferable that the additional compressor 124 is installed upstream of the second compressor 122 because it is expected to increase the efficiency compared to the conventional one but is limited. If an additional compressor 124 is installed downstream of the second compressor 122, the present embodiment can operate in a closed loop and a separate open loop, and the evaporated gas passing through the first feed line L1 and the second feed Since the pressure of the evaporating gas passing through the line L2 is different from each other, it may be difficult to operate as an open loop.

A similar effect can be achieved by increasing the pressure and capacity of the second compressor 122 instead of installing the additional compressor 124 in this embodiment. However, the use of the second compressor 122, which has a larger pressure and a larger capacity, has a disadvantage that the cost is increased.

According to this embodiment, the power produced by the refrigerant decompressor 160 can be utilized, and the additional compressor 124 can be added to increase the re-liquefaction efficiency and the liquefaction amount at a low cost.

The additional cooler 134 of the present embodiment lowers the temperature of the evaporated gas, which is compressed by the additional compressor 124 and which has increased temperature as well as pressure. In the case where the additional compressor 124 is installed upstream of the second compressor 122, the additional compressor 124, the additional cooler 134, the second compressor 122, and the second cooler 132 are installed in this order, When the compressor 124 is installed downstream of the second compressor 122, the second compressor 122, the second cooler 132, the additional compressor 124, and the additional cooler 134 are installed in this order.

The propulsion compressor 126 of the present embodiment is provided with a return line L3 on which a portion of the evaporation gas supplied to the fuel demanding unit 180 is branched along the first supply line L1 to the first heat exchanger 110 And increases the pressure of the evaporation gas supplied to the first heat exchanger 110 along the return line L3. The propulsion compressor 126 may compress the evaporation gas to a pressure below a critical point (in the case of methane, up to about 55 bar), to a pressure exceeding the critical point, and the propulsion compressor 126 of this embodiment evaporates If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.

The propulsion cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126 and passes through the propulsion compressor 126 and lowers the temperature of the evaporated gas as well as the pressure.

The ship of the present embodiment further includes the propelling compressor 126 to increase the pressure of the evaporative gas undergoing the re-liquefaction process, thereby increasing the amount of liquefaction and re-liquefaction efficiency.

9 is a graph showing the temperature values of methane according to the heat flow rate under different pressures, respectively. Referring to FIG. 9, it can be seen that the higher the pressure of the evaporative gas passing through the re-liquefaction process, the higher the efficiency of the self-heat exchange. Self-heat exchanger (Self-) means that heat exchange with high-temperature evaporation gas by using low-temperature evaporation gas itself as cooling fluid.

9 (a) shows the state of each fluid in the second heat exchanger 140 when the propulsion compressor 126 and the propulsion cooler 136 are not included, and Fig. 9 (b) Compressor 126, and propellant cooler 136, respectively, in the second heat exchanger 140. As shown in FIG.

The uppermost graph I in Figures 9 (a) and 9 (b) shows the fluid state at point A in Figure 5 fed into the second heat exchanger 140 along the recycle line L5, The graph L is a graph showing the refrigerant pressure at the point C in FIG. 5, which is fed back to the second heat exchanger 140 for use as a refrigerant after passing through the second heat exchanger 140 and the refrigerant pressure reducing device 160 along the recirculation line L5 The graph J overlapped with the graph K of the middle portion shows the state of the fluid of the second heat exchanger 140, which is supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110, Of the fluid.

Since the fluid used as the refrigerant is deprived of the cold heat during the heat exchange process and the temperature gradually increases, the graph L advances from the left to the right according to the passage of time, and the fluid cooled by heat exchange with the refrigerant is cooled from the refrigerant in the heat exchange process Since the temperature is gradually decreased due to the supply, the graph I and the graph J proceed from right to left as time passes.

A graph K in the middle part of FIGS. 9A and 9B is a combination of the graph I and the graph J. In FIG. That is, the fluid used as the refrigerant in the second heat exchanger 140 is drawn in a graph L, and the fluid cooled by heat exchange with the refrigerant in the second heat exchanger 140 is drawn in the graph K.

In designing the heat exchanger, the temperature and the heat flow of the fluid supplied to the heat exchanger (i.e., the points A, C, and E in FIG. 5) are fixed and the temperature of the fluid used as the refrigerant is higher than the temperature of the fluid So that the logarithmic mean temperature difference (LMTD) can be minimized while preventing the graph L from crossing the graph K so that the graph L does not appear above the graph K.

The logarithmic mean temperature difference (LMTD) is the temperature difference between the low-temperature fluid and the low-temperature fluid in the opposite direction and the opposite direction. In the case of countercurrent flow, the low-temperature fluid passes through the heat exchanger And the temperature after the high-temperature fluid has passed through the heat exchanger is th2 and d1 = th2-tc1, d2 = th1-tc2, d1) / ln (d2 / d1). As the logarithmic mean temperature difference is smaller, the efficiency of the heat exchanger increases.

The logarithmic mean temperature difference (LMTD) on the graph is represented by the interval between the low temperature fluid used as the coolant (graph L in FIG. 9) and the high temperature fluid cooled by heat exchange with the coolant (graph K in FIG. 9) 9 (b) shows that the interval between the graph L and the graph K is narrower than the interval between the graph L and the graph K.

5, which is supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110, is the initial value of the graph J, The pressure of the fluid at the point E appears because the pressure of the fluid at point E is higher than that of FIG. 9 (a).

That is, as a result of the simulation, in the case of Fig. 9 (a) which does not include the propulsion compressor 126, the fluid at point E in Fig. 5 may be approximately -111 캜, 20 bar and includes the propulsion compressor 126 In the case of FIG. 9 (b), the fluid at point E in FIG. 5 may be approximately -90.degree. C., 50 bar. If the heat exchanger is designed so that the logarithmic mean temperature difference (LMTD) , The efficiency of the heat exchanger becomes higher in the case of FIG. 9 (b) in which the pressure of the evaporative gas passing through the re-liquefaction process is high. As a result, the re-liquefaction amount and the re-

9A, when the flow rate of the evaporation gas used as the refrigerant in the second heat exchanger 140 is approximately 6401 kg / h, the refrigerant is heat-exchanged with the refrigerant from the fluid (graph L) (Graph K) is approximately 585.4 kW and the flow rate of the re-liquefied vapor is approximately 3441 kg / h.

9B, when the flow rate of the evaporative gas used as the refrigerant in the second heat exchanger 140 is approximately 5368 kg / h, the refrigerant is heat-exchanged with the refrigerant from the fluid (graph L) (Graph K) is approximately 545.2 kW, and the flow rate of the re-liquefied evaporation gas is approximately 4325 kg / h.

That is, it can be seen that, by increasing the pressure of the evaporation gas passing through the re-liquefaction process including the propelling compressor 126, a larger amount of evaporation gas can be re-liquefied even with a smaller amount of refrigerant.

Since the ship of this embodiment includes the propelling compressor 126, it is possible to increase the amount of liquefaction and re-liquefaction efficiency, increase the amount of liquefaction and re-liquefaction, It is possible to reduce the frequency of use of the second compressor 122.

The concept of redundancy in which the first compressor 120 is broken is considered as the longer the time for driving the second compressor 122 is longer than the second compressor 122, It becomes weak. The ship of the present embodiment can reduce the frequency of use of the second compressor 122 including the propulsion compressor 126, and therefore, the concept of redundancy can be sufficiently secured.

Further, since the propulsion compressor 126 is generally sufficient to have approximately one-half capacity of the first compressor 120 or the second compressor 122, the propulsion compressor 126 ) And the first compressor 120 to operate the system, the operation cost can be saved as compared with the case where the propulsion compressor 126 is not installed.

Referring again to FIG. 5, one side of the first additional line L6 of the present embodiment is connected to a first supply line (not shown) which is expanded by the refrigerant pressure-reducing device 160 and then passed through the second heat exchanger 140 L1 and the other side is connected on the second supply line L2 between the third valve 193 and the second compressor 122. [

The ninth valve 201 of the present embodiment has a point where the recycle line L5 meets the first supply line L1 upstream of the first compressor 120 and the second compressor 122 and the point where the recycle line L5 Is installed on the recycle line (L5) between the point where it meets the first additional line (L6). The ship of this embodiment is different from the third embodiment in that the second supply line L2 on the downstream side of the second compressor 122 is connected to the recycle line L5 rather than the first supply line L1.

The twelfth valve 205 of this embodiment is installed on the recirculation line L5 between the second supply line L2 and the second heat exchanger 140 to regulate the flow rate and opening and closing of the fluid.

The first to twelfth valves 191, 192, 193, 194, 195, 196, 197, 198, 201, 202, 203 and 205 of the present embodiment may be manually controlled And may be automatically adjusted to be opened or closed by a preset value.

The difference from the third embodiment of the present invention is that the refrigerant cycle can be operated not only as an open loop but also as a closed loop to more flexibly use the re-liquefaction system according to the operating conditions of the ship, Hereinafter, when the additional compressor 124 is installed upstream of the second compressor 122, a method of operating the refrigerant cycle as a closed loop and a method of operating the refrigerant cycle as an open loop through valve control will be described.

The first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the tenth valve 202 And the twelfth valve 205 are opened and the sixth valve 196 and the ninth valve 201 are closed.

When the evaporated gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recycle line L5, the third valve 193 is closed and the evaporated gas is supplied to the additional compressor 124, The second compressor 122, the second cooler 132, the fourth valve 194, the twelfth valve 205, the second heat exchanger 140, the refrigerant pressure reducing device 160, 2 heat exchanger (140), and the tenth valve (202).

When the refrigerant cycle is constituted by a closed loop, nitrogen gas may be used as the refrigerant circulating in the closed loop. In this case, the storage tank including the storage tank of the present embodiment may further include a pipe for introducing the nitrogen gas into the refrigerant cycle of the closed loop.

When the refrigerant cycle is operated as a closed loop, only the evaporated gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the evaporated gas passing through the first compressor 120 is not introduced into the refrigerant cycle It is supplied to the fuel consumer station 180 or is subjected to a liquefaction process along the return line L3. Therefore, the evaporation gas at a constant flow rate is circulated to the refrigerant of the second heat exchanger 140 irrespective of the re-liquefaction amount or the evaporation gas amount required by the fuel demanding unit 180. [

It is easy to control the flow rate of each of the evaporation gas subjected to the re-liquefaction process and the evaporation gas used as the refrigerant, compared with the case where the refrigerant cycle of this embodiment is operated as a closed loop, .

Since only one compressor 120 is installed in the first supply line L1 and two compressors 122 and 124 are provided in the second supply line L2 of the present embodiment, And the pressure of the evaporation gas passing through the second supply line L2 may be different from each other. When the pressure of the evaporation gas passing through the first supply line L1 and the pressure of the evaporation gas passing through the second supply line L2 are different, the refrigerant cycle of the present embodiment is preferably operated as a closed loop or an independent closed loop Do.

The flow of the evaporative gas in the case where the refrigerant cycle of the ship of this embodiment is operated as a closed loop will be described as follows.

The evaporated gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, And the remainder is subjected to a re-liquefaction process along the return line L3.

The evaporative gas passing through the re-liquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then supplied to the storage tank T by the first heat exchanger 110. [ Exchanged with the evaporated gas discharged from the evaporator. The evaporated gas cooled by the first heat exchanger (110) is heat-exchanged in the second heat exchanger (140), is further cooled, and then expanded by the first decompressor (150) to partially or totally re-liquefy.

In the present embodiment, the evaporative gas passing through the re-liquefaction process along the return line L3 is compressed by the propelling compressor 126, and then, in the first heat exchanger 110 and the second heat exchanger 140, However, the evaporated gas compressed by the propelling compressor 126 may be directly sent to the second heat exchanger 140, cooled, and then expanded and re-liquefied by the first decompressor 150. The same applies to the case where the refrigerant cycle of this embodiment is operated as an open loop and an independent open loop.

In the case where the ship of this embodiment does not include the gas-liquid separator 170, the evaporated gas partially or totally re-liquefied is directly sent to the storage tank T. When the ship of this embodiment includes the gas-liquid separator 170 The evaporated gas partially or totally re-liquefied is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T).

On the other hand, the evaporative gas circulating the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, then further compressed by the second compressor 122 and further compressed by the second cooler 132 Cooled, and sent to the second heat exchanger 140 along the recycle line L5. The evaporated gas sent to the second heat exchanger 140 after passing through the additional compressor 124 and the second compressor 122 is firstly heat-exchanged and cooled by the second heat exchanger 140, So that it is expanded and cooled secondarily.

In this embodiment, the evaporation gas used as the refrigerant along the recycle line L5 is sent back to the second heat exchanger 140 via the second heat exchanger 140 after passing through the second heat exchanger 140 The evaporated gas used as the refrigerant along the recycle line L5 is sent directly to the refrigerant depressurization device 160 without passing through the second heat exchanger 140 and then sent to the second heat exchanger 140 Can be sent. The same applies to the case where the refrigerant cycle of this embodiment is operated as an open loop and an independent open loop.

The evaporated gas that has passed through the refrigerant decompressor 160 is again sent to the second heat exchanger 140 and then supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 Evaporated gas; And the evaporation gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recycle line L5. The evaporated gas used as the refrigerant in the second heat exchanger 140 after passing through the refrigerant decompressor 160 is again sent to the additional compressor 124 and repeats the above-described series of processes.

When the first compressor (120) or the first cooler (130) breaks down while the refrigerant cycle of the ship of this embodiment is operated as a closed loop, the first valve (191), the second valve The first valve 202 and the twelfth valve 205 are closed and the third valve 193 and the sixth valve 196 are opened to discharge the vaporized vapor that has passed through the first heat exchanger 110 after being discharged from the storage tank T The gas is circulated through the third valve 193, the additional compressor 124, the additional cooler 134, the second compressor 122, the second cooler 132, the fourth valve 194 and the sixth valve 196 So that it is supplied to the fuel demanding unit 180. When it is necessary to use the evaporated gas compressed by the additional compressor 124 and the second compressor 122 as the refrigerant of the second heat exchanger 140, the ninth valve 201 and the twelfth valve 205, To open the system and operate the system.

The first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the sixth valve 196, the second valve 193, The ninth valve 201 and the twelfth valve 205 are opened and the tenth valve 202 is closed.

When the refrigerant cycle is operated as a closed loop, the evaporating gas circulating the refrigerant cycle is separated from the evaporating gas that is sent to the fuel consumer 180 or is subjected to the re-liquefaction process along the return line L3. On the other hand, when the refrigerant cycle is operated as an open loop, the evaporated gas compressed by the first compressor 120 and the evaporated gas compressed by the second compressor 122 are combined, and the refrigerant is introduced into the second heat exchanger 140 Or is sent to the fuel consumer 180, or is re-liquefied along the return line L3.

Therefore, when the refrigerant cycle is operated as an open loop, the flow rate of the refrigerant to be sent to the second heat exchanger 140 can be flexibly controlled in consideration of the amount of resolidification and the amount of evaporation gas required at the fuel consumption site 180. Particularly, when the amount of evaporation gas required in the fuel consumption site 180 is small, the re-liquefaction efficiency and the amount of liquefaction can be increased by increasing the flow rate of the refrigerant sent to the second heat exchanger 140.

The flow of the evaporative gas in the case where the refrigerant cycle of the ship of this embodiment is operated as an open loop will be described as follows.

The evaporated gas discharged from the storage tank T is branched into two flows after passing through the first heat exchanger 110 and a part thereof is sent to the first supply line L1 and the remaining part is supplied to the second supply line L2, Lt; / RTI >

The evaporated gas sent to the first feed line L1 passes through the first valve 191, the first compressor 120, the first cooler 130 and the second valve 192, 196 and the twelfth valve 205 to the second heat exchanger 140 and the other part branches again into two flows. One of the evaporative gases branched off into the two flows is sent to the fuel consumer 180 and the remainder is sent to the propulsion compressor 126 along the return line L3.

The evaporated gas sent to the second feed line L2 is supplied to the third valve 193 via the third valve 193, the additional compressor 124, the additional cooler 134, the second compressor 122, the second cooler 132, 194, a portion is passed through the twelfth valve 205 to the second heat exchanger 140 and the other portion is sent to the first supply line L1 and then branches to two flows. One of the evaporated gases that diverted into two flows is sent to the fuel consumer 180 and the remaining stream is sent to the propulsion compressor 126 along the return line L3.

For convenience of explanation, the evaporated gas compressed by the first compressor 120 and the evaporated gas compressed by the additional compressor 124 and the second compressor 122 are separately described. However, in the first compressor 120, The evaporated gas compressed by the second compressor 122 and the additional compressor 124 and the evaporated gas compressed by the second compressor 122 do not flow separately but merge and flow into the second heat exchanger 140, And is supplied to the compressor 126.

That is, a recycle line L5 for sending the evaporation gas to the second heat exchanger 140, a first supply line L1 for sending the evaporation gas to the fuel consumer 180, and a second supply line L1 for sending the evaporation gas to the first heat exchanger 110 In the return line L3, the evaporated gas compressed by the first compressor 120 and the evaporated gas compressed by the additional compressor 124 and the second compressor 122 are mixed and flowed.

The evaporated gas sent to the second heat exchanger 140 along the recycle line L5 is firstly heat-exchanged and cooled by the second heat exchanger 140 and is expanded by the refrigerant depressurization device 160 to be secondarily cooled And then supplied to the second heat exchanger 140 again. The evaporated gas supplied to the second heat exchanger 140 after passing through the refrigerant decompressor 160 flows through the first heat exchanger 110 and then flows to the second heat exchanger 140 along the return line L3 The supplied evaporating gas; And the evaporator gas compressed by the first compressor 120 and the evaporator gas compressed by the additional compressor 124 and the second compressor 122, which are supplied to the second heat exchanger 140 along the recycle line L5, Is heat exchanged with the combined flow.

The evaporated gas used as the refrigerant in the second heat exchanger 140 after passing through the refrigerant decompressor 160 is sent to the first supply line L1 through the ninth valve 201 and is discharged from the storage tank T After the gas is discharged, the gas is merged with the evaporated gas passing through the first heat exchanger 110, and the above-described series of steps is repeated.

Meanwhile, the evaporated gas sent to the propulsion compressor 126 along the return line L3 is compressed by the propulsion compressor 124, cooled by the propulsion cooler 134, and then sent to the first heat exchanger 110 Loses. The evaporated gas sent to the first heat exchanger 110 is firstly cooled by the first heat exchanger 110 and cooled by the second heat exchanger 140 and then expanded by the first decompressor 150 Some or all of it is re-liquefied.

In the case where the ship of this embodiment does not include the gas-liquid separator 170, the evaporated gas partially or totally re-liquefied is directly sent to the storage tank T. When the ship of this embodiment includes the gas-liquid separator 170 The evaporated gas partially or totally re-liquefied is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T).

When the first compressor (120) or the first cooler (130) fails while the refrigerant cycle of the ship of this embodiment is operated as an open loop, the first valve (191), the second valve (192) The second valve 201 and the twelfth valve 205 are closed so that the evaporated gas that has been discharged from the storage tank T and then passed through the first heat exchanger 110 flows through the third valve 193, The second compressor 122, the second cooler 132, the fourth valve 194, and the sixth valve 196 to the fuel demanding place 180. The additional cooler 134, the second compressor 122, the second cooler 132, When it is necessary to use the evaporated gas compressed by the additional compressor 124 and the second compressor 122 as the refrigerant of the second heat exchanger 140, the ninth valve 201 and the twelfth valve 205, To open the system and operate the system.

The ship of the present embodiment uses the evaporator gas compressed by the second compressor 122 only as the refrigerant of the second heat exchanger 140 while operating the refrigerant cycle in an open loop, The evaporated gas is supplied to the second compressor 122 and the second compressor 122 so as to be sent to the fuel consumer 180 or to be re-liquefied along the return line L3 and not used as the refrigerant of the second heat exchanger 140. [ 1 compressors 120 may be operated independently. Hereinafter, an open loop refrigerant cycle for independently operating the second compressor 122 and the first compressor 120 is referred to as an 'independent open loop'.

The first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the ninth valve 201, and the ninth valve 201 in order to independently operate the refrigerant cycle of the ship of this embodiment. And the twelfth valve (205) are opened, and the sixth valve (196) and the tenth valve (202) are closed. When the refrigerant cycle is operated as an independent open loop, it is possible to operate a relatively fluid system as compared with the closed loop operation, and it is advantageous in that the system can be operated more easily than when the open loop is operated.

The flow of the evaporative gas in the case where the refrigerant cycle of the ship of this embodiment is operated in the independent open loop will be described as follows.

After passing through the first heat exchanger 110, the evaporation gas discharged from the storage tank T is branched into two flows, a part of which is sent to the first supply line L1 and a part of which is supplied to the second supply line L2 . The evaporated gas sent to the first supply line L1 passes through the first valve 191, the first compressor 120, the first cooler 130 and the second valve 192, And the other part is sent to the propulsion compressor 126 along the return line L3.

The evaporated gas sent to the second feed line L2 is supplied to the third valve 193 via the third valve 193, the additional compressor 124, the additional cooler 134, the second compressor 122, the second cooler 132, 194 and the twelfth valve 205 and then to the second heat exchanger 140 along the recirculation line L5.

The evaporated gas that has been compressed by the additional compressor 124 and the second compressor 122 and then sent to the second heat exchanger 140 along the recycle line L5 is first heat exchanged in the second heat exchanger 140 to be cooled The refrigerant is expanded by the refrigerant decompression device 160 to be cooled and then supplied to the second heat exchanger 140. After passing through the first heat exchanger 110 and then through the return line L3, The evaporation gas supplied to the unit 140; And the evaporation gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recycle line L5.

The evaporated gas used as the refrigerant in the second heat exchanger 140 after passing through the refrigerant decompressor 160 is sent to the first supply line L1 through the ninth valve 201 and is discharged from the storage tank T And then merged with the evaporated gas passing through the first heat exchanger 110, and the above-described series of steps is repeated.

The evaporated gas which is compressed by the first compressor 120 and then sent to the propulsion compressor 126 along the return line L3 is compressed by the propulsion compressor 124 and cooled by the propulsion cooler 134, And is sent to the first heat exchanger 110. The evaporated gas sent to the first heat exchanger 110 is firstly cooled by the first heat exchanger 110 and cooled by the second heat exchanger 140 and then expanded by the first decompressor 150 Some or all of it is re-liquefied.

In the case where the ship of this embodiment does not include the gas-liquid separator 170, the evaporated gas partially or totally re-liquefied is directly sent to the storage tank T. When the ship of this embodiment includes the gas-liquid separator 170 The evaporated gas partially or totally re-liquefied is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T).

When the first compressor (120) or the first cooler (130) fails, the first valve (191), the second valve (192), the ninth valve The valve 201 and the twelfth valve 205 are closed and the sixth valve 196 is opened so that the evaporated gas that has been discharged from the storage tank T and then passed through the first heat exchanger 110 flows into the third valve 193), the additional compressor 124, the additional cooler 134, the second compressor 122, the second cooler 132, the fourth valve 194 and the sixth valve 196 to the fuel consumer 180 . When it is necessary to use the evaporated gas compressed by the additional compressor 124 and the second compressor 122 as the refrigerant of the second heat exchanger 140, the ninth valve 201 and the twelfth valve 205, To open the system and operate the system.

FIG. 6 is a schematic view showing a system for processing an evaporative gas of a ship according to a fifth embodiment of the present invention.

The ship of the fifth embodiment shown in Fig. 6 does not include the first additional line L6 and the additional compressor 124 and the additional cooler 134 are recirculated (as compared to the ship of the fourth embodiment shown in Fig. 5) There is a difference in that the connection positions of the respective lines are slightly changed, and the difference will be mainly described below. A detailed description of the same components as those of the ship of the fourth embodiment will be omitted.

Referring to FIG. 6, the ship of the present embodiment is provided with a first heat exchanger 110, a first valve 191, a first compressor 120, a first cooler 130, A third valve 193, a second compressor 122, a second cooler 132, a fourth valve 194, a propelling compressor 126, a propellant cooler 136, a second heat exchanger (not shown) 140, a refrigerant decompressor 160, an additional compressor 124, an additional cooler 134, a ninth valve 201, a twelfth valve 205, and a first decompressor 150.

The first heat exchanger 110 of the present embodiment is configured such that the evaporation gas discharged from the storage tank T is used as the refrigerant and flows along the return line L3 to the first heat exchanger 110 Cool the evaporated gas sent. That is, the first heat exchanger 110 recovers the cold heat of the evaporated gas discharged from the storage tank T and supplies the recovered cold heat to the evaporated gas sent to the first heat exchanger 110 along the return line L3 Supply. On the return line L3, a fifth valve 195 for regulating the flow rate and opening / closing of the evaporation gas may be installed.

The first compressor (120) of this embodiment is provided on the first supply line (L1) to compress the evaporated gas discharged from the storage tank (T) in the same manner as in the fourth embodiment, 122 are provided in parallel with the first compressor 120 on the second supply line L2 to compress the evaporated gas discharged from the storage tank T as in the fourth embodiment. The first compressor (120) and the second compressor (122) may be compressors having the same performance, and each may be a multi-stage compressor.

The first compressor 120 and the second compressor 122 of this embodiment can compress the evaporation gas to the pressure required by the fuel consumer 180 as in the fourth embodiment. When the fuel demanding unit 180 includes various kinds of engines, the evaporating gas is compressed in accordance with the required pressure of the engine requiring a higher pressure (hereinafter referred to as a "high-pressure engine"), Pressure engine provided downstream of the engine (hereinafter referred to as a " low-pressure engine ") which supplies the engine to the engine and the other part that requires a lower pressure. In addition, in order to increase the re-liquefaction efficiency and the liquefaction amount in the first heat exchanger 110 and the second heat exchanger 140, the evaporation gas is supplied to the first compressor (120) or the second compressor (122) A pressure reducing device is provided upstream of the fuel demanding place 180 and the pressure of the evaporating gas compressed at a high pressure is lowered to a pressure required by the fuel demanding place 180, (180).

The vessel of the present embodiment further includes an eleventh valve 203 provided upstream of the fuel demanding place 180 for controlling the flow rate and opening and closing of the evaporating gas sent to the fuel demanding place 180 .

Since the ship of this embodiment uses the evaporated gas compressed by the second compressor 122 as a refrigerant for further cooling the evaporated gas in the second heat exchanger 140 as in the fourth embodiment, The amount of liquefaction can be increased.

The first cooler 130 of the present embodiment is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 as well as the pressure as well as the temperature, The second cooler 132 of the present embodiment is installed downstream of the second compressor 122 in the same manner as the fourth embodiment and cools the evaporated gas passing through the second compressor 122 as well as the pressure as well as the temperature.

The propulsion compressor 126 of the present embodiment branches a part of the evaporation gas supplied to the fuel consumption source 180 along the first supply line L1 to the first heat exchanger 110 as in the fourth embodiment , And is installed on the return line (L3) to raise the pressure of the evaporation gas supplied to the first heat exchanger (110) along the return line (L3). The propulsion compressor 126 may compress the evaporation gas to a pressure below a critical point (in the case of methane, up to about 55 bar), to a pressure exceeding the critical point, and the propulsion compressor 126 of this embodiment evaporates If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.

The propellant cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126 in the same manner as the fourth embodiment and passes through the propellant compressor 126 and the evaporation gas Lt; / RTI >

Since the ship of the present embodiment further includes the propulsion compressor 126, it is possible to increase the pressure of the evaporation gas subjected to the re-liquefaction process to increase the amount of re-liquefaction and the re-liquefaction efficiency as in the fourth embodiment, 122 can be reduced and the concept of redundancy can be sufficiently ensured and the operation cost can be saved as compared with the case where the propulsion compressor 126 is not installed.

The second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 in the same manner as in the fourth embodiment and is supplied to the evaporation gas cooled by the first heat exchanger 110 Lt; / RTI >

According to this embodiment, as in the fourth embodiment, the evaporated gas discharged from the storage tank T is further cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, It is possible to supply the first decompression device 150 with the re-liquefaction efficiency and the liquefaction amount.

The refrigerant pressure reducing device 160 of the present embodiment inflates the evaporation gas that has passed through the second heat exchanger 140 and sends it to the second heat exchanger 140 again as in the fourth embodiment.

The additional compressor 124 of the present embodiment compresses the fluid that has passed through the refrigerant pressure reducing device 160 and the second heat exchanger 140 and is driven by the power that the refrigerant pressure reducing device 160 produces while inflating the fluid . That is, the refrigerant decompressor 160 and the additional compressor 124 of the present embodiment can form a compressor 900. The additional compressor 124 may have a smaller capacity than the second compressor 122 and may be a capacity that can be driven by the power produced by the refrigerant decompression device 160. [

Unlike the fourth embodiment, the additional compressor 124 of the present embodiment is not installed on the second supply line L2 but branched from the second supply line L2 to be connected to the refrigerant pressure- And the fluid that has passed through the second heat exchanger 140 are installed on the recycle line L5 to be sent again to the second supply line L2.

According to the present embodiment, as in the fourth embodiment, the power produced by the refrigerant decompressor 160 can be utilized, and by adding the additional compressor 124 having a capacity smaller than that of the second compressor 122, The re-liquefaction efficiency and the amount of re-liquefaction can be increased.

The additional cooler 134 of this embodiment is installed downstream of the additional compressor 124 and is compressed by the additional compressor 124 to lower the temperature of the evaporated gas as well as the pressure as well as the pressure. However, the additional cooler 134 of this embodiment is provided on the recirculation line L5, unlike the fourth embodiment.

In this embodiment, the additional compressor 124 and the additional cooler 134 are installed on the recycle line L5 so that the fluid used as the refrigerant in the second heat exchanger 140 is supplied to the closed loop refrigerant cycle The first compressor 120 or the first cooler 130 can be circulated through the second compressor 122 and the second cooler 132 more easily than the fourth embodiment when the first compressor 120 or the first cooler 130 fails. So that the evaporated gas can be supplied as fuel to the fuel demanding unit 180.

Hereinafter, the case where the first compressor 120 and the first cooler 130 operate normally is referred to as 'normal', and the case where the first compressor 120 or the first cooler 130 fails is referred to as 'emergency'.

That is, according to the present embodiment, the fluid used as the refrigerant in the second heat exchanger 140 flows along the recycle line L5 and the second supply line L2 to the additional compressor 124, the additional cooler 134, The second compressor 122, the second cooler 132, the second heat exchanger 140, the refrigerant pressure reducing device 160 and the second heat exchanger 140 to the additional compressor 124 again So that the same refrigerant cycle as that of the closed-loop refrigerant cycle of the fourth embodiment is circulated.

On the other hand, according to the fourth embodiment, the evaporative gas supplied to the fuel consumer 180 along the second supply line L2 in an emergency is compressed by both the additional compressor 124 and the second compressor 122, When the second compressor 122 has the same performance as the first compressor 120, the pressure of the evaporative gas supplied to the fuel consumer 180 along the second supply line L2 in an emergency May be higher than the pressure of the evaporative gas supplied to the fuel consumer 180 along the first supply line L1.

Therefore, according to the fourth embodiment, the pressure of the evaporative gas supplied to the fuel consumer 180 along the second supply line L2 in an emergency is supplied to the fuel consumer 180 along the first supply line L1 normally There is a case where it is difficult to utilize the second compressor 122 as the redundancy.

According to the present embodiment, the evaporative gas supplied to the fuel consumer 180 along the second supply line L2 in an emergency can be compressed only by the second compressor 122 without being compressed by the additional compressor 124 When the second compressor 122 has the same performance as that of the first compressor 120, it is possible to easily supply the fuel to the fuel consumer via the second supply line L2 without further pressure regulation in an emergency 180). ≪ / RTI >

The first decompression device 150 of the present embodiment is provided on the return line L3 in the same manner as the fourth embodiment and is provided with the evaporation gas cooled by the first heat exchanger 110 and the second heat exchanger 140 Lt; / RTI > The first decompression device 150 of the present embodiment includes all means capable of expanding and cooling the evaporation gas and may be an expansion valve such as a Joule-Thomson valve or an expander.

As in the fourth embodiment, the vessel of this embodiment is provided on the return line L3 downstream of the first decompressor 150 and separates the gas-liquid mixture discharged from the first decompressor 150 into gas and liquid , And a gas-liquid separator (170).

When the vessel of the present embodiment does not include the gas-liquid separator 170, the evaporated gas in the liquid or gas-liquid mixed state that has passed through the first decompressor 150 is directly sent to the storage tank T When the ship of this embodiment includes the gas-liquid separator 170, the evaporated gas that has passed through the first decompressor 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3 and the gas separated by the gas-liquid separator 170 flows from the gas-liquid separator 170 to the first heat exchanger 110 to the first heat exchanger 110 along a gas discharge line L4 extending to the first supply line L1 upstream of the first heat exchanger 110. [

The seventh valve 197 (hereinafter, referred to as " 197 ") which regulates the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank T, similarly to the fourth embodiment, ); And an eighth valve (198) for controlling the flow rate of the gas separated by the gas-liquid separator (170) and sent to the first heat exchanger (110).

However, unlike the fourth embodiment, the ship of the present embodiment does not include the first additional line L6 and the second supply line L2 branched from the first supply line L1 is connected to the recirculation line L5 ) And the first supply line (L1). The recycle line L5 is branched from the second supply line L2 between the second cooler 132 and the fourth valve 194 rather than the first supply line L1 and then flows through the first supply line L1 L1) and the second supply line (L2) between the third valve (193) and the second compressor (122).

In addition, the ship of the present embodiment does not include the sixth valve 196 unlike the fourth embodiment.

In this embodiment, the evaporated gas discharged from the storage tank T, including the first heat exchanger 110, is heat-exchanged in the first heat exchanger 110, and then the first compressor 120 or the second compressor 122, The vessel of the present invention does not include the first heat exchanger 110 and the evaporated gas discharged from the storage tank T is directly supplied to the first compressor 120 or the second compressor 122 And the evaporative gas passing through the re-liquefaction process along the return line L3 may be sent to the second heat exchanger 140 after being compressed by the propelling compressor 126. [ The sixth embodiment to be described later is also the same.

In this embodiment, the fluid circulating along the recirculation line L5 is firstly passed through the second heat exchanger 140, expanded by the refrigerant decompressor 160, and then supplied to the second heat exchanger 140 The fluid circulating along the recirculation line L5 of the present invention is expanded by the refrigerant pressure reducing device 160 after branched from the second supply line L2 and then circulated through the second heat exchanger 140 ≪ / RTI > The sixth embodiment to be described later is also the same.

The first to fifth valves, seventh to ninth valves, eleventh valves and twelfth valves (191, 192, 193, 194, 195, 197, 198, 201, 203, 205) The situation may be manually adjusted by the person himself or may be automatically adjusted to be opened or closed by a predetermined value.

The refrigerant cycle of the present embodiment is preferably operated as a closed loop. Hereinafter, a method of operating the refrigerant cycle of the present embodiment as a closed loop through valve control will be described.

The first valve 191, the second valve 192, the third valve 193, the fourth valve 194 and the fifth valve 195 ), The ninth valve 201, and the twelfth valve 205 are opened.

When the evaporated gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recycle line L5, the third valve 193 and the fourth valve 194 are closed, The second compressor 122, the second cooler 132, the twelfth valve 205, the second heat exchanger 140, the refrigerant pressure reducing device 160, the second heat exchanger 140, the additional compressor 124, The additional cooler 134, and the ninth valve 201. The refrigerant cycle of the closed loop,

When the refrigerant cycle is constituted by a closed loop, nitrogen gas may be used as the refrigerant circulating in the closed loop. In this case, the storage tank T including the storage tank T of the present embodiment may further include a pipe for introducing the nitrogen gas into the refrigerant cycle of the closed loop.

When the refrigerant cycle is operated as a closed loop, only the evaporated gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the evaporated gas passing through the first compressor 120 is not introduced into the refrigerant cycle It is supplied to the fuel consumer station 180 or is subjected to a liquefaction process along the return line L3. Therefore, the evaporation gas at a constant flow rate is circulated to the refrigerant of the second heat exchanger 140 irrespective of the re-liquefaction amount or the evaporation gas amount required by the fuel demanding unit 180. [

It is easy to control the flow rate of each of the evaporation gas subjected to the re-liquefaction process and the evaporation gas used as the refrigerant, compared with the case where the refrigerant cycle of this embodiment is operated as a closed loop, .

The flow of the evaporative gas in the case where the refrigerant cycle of the ship of this embodiment is operated as a closed loop will be described as follows.

The evaporated gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, And the remainder is subjected to a re-liquefaction process along the return line L3.

The evaporated gas that has passed through the first heat exchanger 110 after being discharged from the storage tank T may be approximately 1 bar and approximately 1 bar of evaporated gas is compressed by the first compressor 120 to approximately 17 bar . The pressure of the evaporated gas compressed by the first compressor 120 may vary depending on the re-liquefaction performance required by the system and the operating conditions of the system.

The evaporative gas passing through the re-liquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then supplied to the storage tank T by the first heat exchanger 110. [ Exchanged with the evaporated gas discharged from the evaporator. The evaporated gas cooled by the first heat exchanger (110) is heat-exchanged in the second heat exchanger (140), is further cooled, and then expanded by the first decompressor (150) to partially or totally re-liquefy.

In the case where the ship of this embodiment does not include the gas-liquid separator 170, the evaporated gas partially or totally re-liquefied is directly sent to the storage tank T. When the ship of this embodiment includes the gas-liquid separator 170 The evaporated gas partially or totally re-liquefied is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T).

On the other hand, the evaporative gas circulating the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, then further compressed by the second compressor 122 and further compressed by the second cooler 132 Cooled, and sent to the second heat exchanger 140 along the recycle line L5. The evaporated gas sent to the second heat exchanger 140 after passing through the additional compressor 124 and the second compressor 122 is firstly heat-exchanged and cooled by the second heat exchanger 140, So that it is expanded and cooled secondarily.

The evaporation gas compressed by the additional compressor 124 may be approximately 2 bar and the evaporation gas approximately 2 bar may be compressed by the second compressor 122 to approximately 32 bar. The pressure of the evaporated gas compressed by the additional compressor 124 and the pressure of the evaporated gas compressed by the second compressor 122 may vary depending on the remapping performance required by the system and the operating conditions of the system.

The evaporated gas that has passed through the refrigerant decompressor 160 is again sent to the second heat exchanger 140 and then supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 Evaporated gas; And the evaporation gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recycle line L5. The evaporated gas used as the refrigerant in the second heat exchanger 140 after passing through the refrigerant decompressor 160 is again sent to the additional compressor 124 and repeats the above-described series of processes.

When the first compressor (120) or the first cooler (130) fails while the refrigerant cycle of the ship of this embodiment is operated as a closed loop, the first valve (191), the second valve (192) The first valve 201 and the twelfth valve 205 are closed and the third valve 193 and the fourth valve 194 are opened so as to be discharged from the storage tank T and then evaporated through the first heat exchanger 110 The gas is supplied to the fuel consumer 180 via the third valve 193, the second compressor 122, the second cooler 132, and the fourth valve 194. [

FIG. 7 is a schematic view showing a system for processing an evaporative gas of a ship according to a sixth embodiment of the present invention.

The ship of the sixth embodiment shown in Fig. 7 has a second additional line L11, a thirteenth valve 206 installed on the second additional line L11 as compared with the ship of the fifth embodiment shown in Fig. 6, The seventh additional line L13, and the seventh additional line L13 provided on the third additional line L12, the seventh additional line L12, the seventh additional line L13, (208), and the difference will be mainly described below. A detailed description of the same members as those of the ship of the fifth embodiment will be omitted.

7, the ship of the present embodiment is provided with a first heat exchanger 110, a first valve 191, a first compressor 120, a first cooler 130, a second A third valve 193, a second compressor 122, a second cooler 132, a fourth valve 194, a propelling compressor 126, a propellant cooler 136, a second heat exchanger (not shown) 140, a refrigerant decompressor 160, an additional compressor 124, an additional cooler 134, a ninth valve 201, a twelfth valve 205, and a first decompressor 150.

The first heat exchanger 110 of the present embodiment uses the evaporation gas discharged from the storage tank T as the refrigerant and supplies it to the first heat exchanger 110 along the return line L3 Cool the evaporated gas sent. That is, the first heat exchanger 110 recovers the cold heat of the evaporated gas discharged from the storage tank T and supplies the recovered cold heat to the evaporated gas sent to the first heat exchanger 110 along the return line L3 Supply. On the return line L3, a fifth valve 195 for regulating the flow rate and opening / closing of the evaporation gas may be installed.

The first compressor (120) of this embodiment is provided on the first supply line (L1) to compress the evaporated gas discharged from the storage tank (T) in the same manner as in the fifth embodiment, 122 are provided in parallel with the first compressor 120 on the second supply line L2 to compress the evaporated gas discharged from the storage tank T as in the fifth embodiment. The first compressor (120) and the second compressor (122) may be compressors having the same performance, and each may be a multi-stage compressor.

The first compressor 120 and the second compressor 122 of this embodiment can compress the evaporation gas at the pressure required by the fuel consumer 180 as in the fifth embodiment. When the fuel demanding unit 180 includes various kinds of engines, the evaporating gas is compressed in accordance with the required pressure of the engine requiring a higher pressure (hereinafter referred to as a "high-pressure engine"), Pressure engine provided downstream of the engine (hereinafter referred to as a " low-pressure engine ") which supplies the engine to the engine and the other part that requires a lower pressure. In addition, in order to increase the re-liquefaction efficiency and the liquefaction amount in the first heat exchanger 110 and the second heat exchanger 140, the evaporation gas is supplied to the first compressor (120) or the second compressor (122) A pressure reducing device is provided upstream of the fuel demanding place 180 and the pressure of the evaporating gas compressed at a high pressure is lowered to a pressure required by the fuel demanding place 180, (180).

The vessel of the present embodiment further includes an eleventh valve 203 provided upstream of the fuel demanding place 180 for controlling the flow rate and the opening and closing of the evaporating gas sent to the fuel demanding place 180 .

The first cooler 130 of the present embodiment is installed downstream of the first compressor 120 to cool the evaporated gas passing through the first compressor 120 as well as the pressure as well as the temperature, The second cooler 132 of the present embodiment is installed downstream of the second compressor 122, and passes through the second compressor 122 to cool not only the pressure but also the temperature of the evaporated gas, as in the fifth embodiment.

The propulsion compressor 126 of this embodiment is installed on the return line L3 to increase the pressure of the evaporation gas supplied to the first heat exchanger 110 along the return line L3 as in the fifth embodiment . The propulsion compressor 126 may compress the evaporation gas to a pressure below a critical point (in the case of methane, up to about 55 bar), to a pressure exceeding the critical point, and the propulsion compressor 126 of this embodiment evaporates If the gas is compressed to above the critical point, it can be compressed to approximately 300 bar.

The propulsive cooler 136 of this embodiment is installed on the return line L3 downstream of the propulsion compressor 126 and passes through the propulsion compressor 126 as well as the pressure and the evaporation gas Lt; / RTI >

Since the ship of the present embodiment further includes the propelling compressor 126, it is possible to increase the amount of liquefied gas and raise the liquefaction efficiency by raising the pressure of the evaporative gas undergoing the liquefaction process as in the fifth embodiment, It is possible to secure enough, and the operation cost can be saved.

The second heat exchanger 140 of the present embodiment is supplied to the first heat exchanger 110 along the return line L3 in the same manner as the fifth embodiment and is supplied to the first heat exchanger 110, Lt; / RTI >

According to the present embodiment, as in the fifth embodiment, the evaporated gas discharged from the storage tank T is further cooled not only in the first heat exchanger 110 but also in the second heat exchanger 140, It is possible to supply the first decompression device 150 with the re-liquefaction efficiency and the liquefaction amount.

As in the fifth embodiment, the refrigerant pressure reducing device 160 of the present embodiment expands the evaporated gas that has passed through the second heat exchanger 140, and then sends it to the second heat exchanger 140 again.

The additional compressor 124 of this embodiment is disposed on the recirculation line L5 to compress the fluid that has passed through the refrigerant pressure reducing device 160 and the second heat exchanger 140, as in the fifth embodiment. Further, the additional compressor 124 of this embodiment is driven by the power generated by expanding the fluid in the refrigerant depressurization device 160, and the refrigerant depressurization device 160 and the additional compressor 124, similar to the fifth embodiment, A compander 900 may be formed. The additional compressor 124 may have a smaller capacity than the second compressor 122 and may be a capacity that can be driven by the power produced by the refrigerant decompression device 160. [

According to the present embodiment, as in the fifth embodiment, the power produced by the refrigerant pressure-reducing device 160 can be utilized and the additional compressor 124 (124) having a smaller capacity than the first compressor 120 or the second compressor 122 ), It is possible to increase the re-liquefaction efficiency and the amount of re-liquefaction at a low cost.

The additional cooler 134 of the present embodiment is installed downstream of the additional compressor 124 on the recycle line L5 and is compressed by the additional compressor 124 as well as the pressure, Lt; / RTI >

In this embodiment, as in the fifth embodiment, the additional compressor 124 and the additional cooler 134 are provided on the recycle line L5 so that the fluid used as the coolant in the second heat exchanger 140 is supplied to the It is possible to circulate the same route as the closed-loop refrigerant cycle of the fourth embodiment, and the first compressor 120 or the first cooler 130 fails, the second compressor 122 and the second compressor The evaporated gas that has passed through the cooler 132 can be supplied as fuel to the fuel consumer 180. When the second compressor 122 or the second cooler 132 fails in operation while the system is being operated to supply the evaporated gas compressed by the second compressor 122 to the fuel consumer 180 as described later , It is possible to supply the evaporative gas, which has passed through the first compressor (120) and the first cooler (130), to the fuel demanding place (180) more easily than the fourth embodiment.

The first decompression device 150 of the present embodiment is provided on the return line L3 in the same manner as the fifth embodiment and is provided with the evaporation gas cooled by the first heat exchanger 110 and the second heat exchanger 140 Lt; / RTI > The first decompression device 150 of the present embodiment includes all means capable of expanding and cooling the evaporation gas and may be an expansion valve such as a Joule-Thomson valve or an expander.

As in the fifth embodiment, the vessel of this embodiment is provided on the return line L3 downstream of the first decompressor 150 and separates the gas-liquid mixture discharged from the first decompressor 150 into gas and liquid , And a gas-liquid separator (170).

When the vessel of the present embodiment does not include the gas-liquid separator 170, the evaporated gas in the liquid or gas-liquid mixed state that has passed through the first decompressor 150 is directly sent to the storage tank T When the ship of this embodiment includes the gas-liquid separator 170, the evaporated gas that has passed through the first decompressor 150 is sent to the gas-liquid separator 170 to separate the gas phase and the liquid phase. The liquid separated by the gas-liquid separator 170 returns to the storage tank T along the return line L3 and the gas separated by the gas-liquid separator 170 flows from the gas-liquid separator 170 to the first heat exchanger 110 to the first heat exchanger 110 along a gas discharge line L4 extending to the first supply line L1 upstream of the first heat exchanger 110. [

Liquid separator 170. The seventh valve 197, which regulates the flow rate of the liquid separated by the gas-liquid separator 170 and sent to the storage tank T, ); And an eighth valve (198) for controlling the flow rate of the gas separated by the gas-liquid separator (170) and sent to the first heat exchanger (110).

The ship of the present embodiment does not include the first additional line L6 and the second supply line L2 branched from the first supply line L1 is connected to the first supply line L1 and the recycle line L5 is branched from the second supply line L2 between the second cooler 132 and the fourth valve 194 and thereafter the third valve 193 and the second And then rejoins the second supply line (L2) between the compressors (122).

However, unlike the fifth embodiment, the ship of this embodiment has a second additional line L11; A thirteenth valve (206) installed on the second additional line (L11); A third additional line L12; A fourteenth valve (207) installed on the third additional line (L12); A fourth additional line L13; And a fifteenth valve (208) installed on the fourth additional line (L13).

The second additional line L11 of the present embodiment is branched from the recirculation line L5 between the additional cooler 134 and the ninth valve 201 and is branched from the first valve 191 and the first compressor 120 1 supply line L1.

The third additional line L12 of the present embodiment is branched from the first supply line L1 between the first cooler 130 and the second valve 192 and connected to the twelfth valve 205 and the second heat exchanger 140 To the recirculation line L5.

The fourth additional line L13 of the present embodiment is branched from the second supply line L2 between the second cooler 132 and the fourth valve 194 and flows between the fifth valve 195 and the propulsion compressor 126 To the return line L3.

According to the present embodiment, unlike the fifth embodiment, both the first compressor 120 and the second compressor 122 are used for compressing the evaporative gas supplied to the refrigerant cycle; Or to compress the evaporative gas supplied to the fuel demanding unit 180. [ According to the present embodiment, unlike the fifth embodiment, not only the evaporation gas branched from the first supply line L1 but also the evaporation gas branched from the second supply line L2 is also selectively supplied to the return line L3 The liquefaction process can be performed.

That is, according to the fifth embodiment, the evaporated gas compressed by the first compressor 120 in the normal state is sent to the fuel consumer 180 or is re-liquefied along the return line L3, The first compressor 120 and the second compressor 122 can not be used differently from each other because the evaporated gas compressed by the first compressor 120 circulates the refrigerant cycle.

According to the present embodiment, the first compressor 120 and the second compressor 122 are selected to supply the evaporative gas to the fuel consumer 180 or the return line L3, The refrigerant cycle can be circulated with the evaporated gas compressed by another compressor which does not supply the evaporated gas to the evaporator. Therefore, according to the present embodiment, there is an advantage that the system can be operated more freely than the fifth embodiment.

The seventh to ninth valves, the eleventh to fifteenth valves 191, 192, 193, 194, 195, 197, 198, 201, 203, 205, 206, 207, and 208 may be manually adjusted by a person directly determining the system operation status, or may be automatically adjusted to be opened or closed by a predetermined value.

The refrigerant cycle of the present embodiment is preferably operated as a closed loop. Hereinafter, a method of operating the refrigerant cycle of the present embodiment as a closed loop through valve control will be described.

The refrigerant cycle of the ship of this embodiment is operated as a closed loop and the evaporated gas compressed by the first compressor 120 is sent to the fuel consumer 180 and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122 The first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the fifth valve 195, the ninth valve 201, The twelfth valve 205 is opened and the thirteenth valve 206, the fourteenth valve 207 and the fifteenth valve 208 are driven in a closed state.

When the evaporated gas compressed by the second compressor 122 after being discharged from the storage tank T is supplied to the recycle line L5, the third valve 193 and the fourth valve 194 are closed, The second compressor 122, the second cooler 132, the twelfth valve 205, the second heat exchanger 140, the refrigerant pressure reducing device 160, the second heat exchanger 140, the additional compressor 124, The additional cooler 134, and the ninth valve 201. The refrigerant cycle of the closed loop,

When the refrigerant cycle is constituted by a closed loop, nitrogen gas may be used as the refrigerant circulating in the closed loop. In this case, the storage tank T including the storage tank T of the present embodiment may further include a pipe for introducing the nitrogen gas into the refrigerant cycle of the closed loop.

When the refrigerant cycle is operated as a closed loop, only the evaporated gas circulating in the closed loop is used as the refrigerant in the second heat exchanger 140, and the evaporated gas passing through the first compressor 120 is not introduced into the refrigerant cycle It is supplied to the fuel consumer station 180 or is subjected to a liquefaction process along the return line L3. Therefore, the evaporation gas at a constant flow rate is circulated to the refrigerant of the second heat exchanger 140 irrespective of the re-liquefaction amount or the evaporation gas amount required by the fuel demanding unit 180. [

It is easy to control the flow rate of each of the evaporation gas subjected to the re-liquefaction process and the evaporation gas used as the refrigerant, compared with the case where the refrigerant cycle of this embodiment is operated as a closed loop, .

The refrigerant cycle of the ship of this embodiment is operated as a closed loop and the evaporated gas compressed by the first compressor 120 is sent to the fuel consumer 180 and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122 The flow of the evaporating gas will be described as follows.

The evaporated gas discharged from the storage tank T is compressed by the first compressor 120 after passing through the first heat exchanger 110 and cooled by the first cooler 130, And the remainder is subjected to a re-liquefaction process along the return line L3.

The evaporated gas that has passed through the first heat exchanger 110 after being discharged from the storage tank T may be approximately 1 bar and approximately 1 bar of evaporated gas is compressed by the first compressor 120 to approximately 17 bar . The pressure of the evaporated gas compressed by the first compressor 120 may vary depending on the re-liquefaction performance required by the system and the operating conditions of the system.

The evaporative gas passing through the re-liquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then supplied to the storage tank T by the first heat exchanger 110. [ Exchanged with the evaporated gas discharged from the evaporator. The evaporated gas cooled by the first heat exchanger (110) is heat-exchanged in the second heat exchanger (140), is further cooled, and then expanded by the first decompressor (150) to partially or totally re-liquefy.

In the case where the ship of this embodiment does not include the gas-liquid separator 170, the evaporated gas partially or totally re-liquefied is directly sent to the storage tank T. When the ship of this embodiment includes the gas-liquid separator 170 The evaporated gas partially or totally re-liquefied is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T).

On the other hand, the evaporative gas circulating the refrigerant cycle is compressed by the additional compressor 124 and cooled by the additional cooler 134, then further compressed by the second compressor 122 and further compressed by the second cooler 132 Cooled, and sent to the second heat exchanger 140 along the recycle line L5. The evaporated gas sent to the second heat exchanger 140 after passing through the additional compressor 124 and the second compressor 122 is firstly heat-exchanged and cooled by the second heat exchanger 140, So that it is expanded and cooled secondarily.

The evaporation gas compressed by the additional compressor 124 may be approximately 2 bar and the evaporation gas approximately 2 bar may be compressed by the second compressor 122 to approximately 32 bar. The pressure of the evaporated gas compressed by the additional compressor 124 and the pressure of the evaporated gas compressed by the second compressor 122 may vary depending on the remapping performance required by the system and the operating conditions of the system.

The evaporated gas that has passed through the refrigerant decompressor 160 is again sent to the second heat exchanger 140 and then supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 Evaporated gas; And the evaporation gas compressed by the additional compressor 124 and the second compressor 122 and then supplied to the second heat exchanger 140 along the recycle line L5. The evaporated gas used as the refrigerant in the second heat exchanger 140 after passing through the refrigerant decompressor 160 is again sent to the additional compressor 124 and repeats the above-described series of processes.

The refrigerant cycle of the ship of this embodiment is operated as a closed loop and the evaporated gas compressed by the first compressor 120 is sent to the fuel consumer 180 and the refrigerant cycle is compressed by the evaporated gas compressed by the second compressor 122 The first valve 191, the second valve 192, the fifth valve 195, the ninth valve 201, and the second valve 191 when the first compressor 120 or the first cooler 130 fails, And the twelfth valve 205 are closed and the third valve 193 and the fourth valve 194 are opened to allow the evaporated gas that has been discharged from the storage tank T and then passed through the first heat exchanger 110 And is supplied to the fuel consumer 180 via the third valve 193, the second compressor 122, the second cooler 132, and the fourth valve 194.

The refrigerant cycle of the ship of the present embodiment is operated in a closed loop, the evaporated gas compressed by the second compressor 122 is sent to the fuel consumer 180, the refrigerant cycle is compressed by the evaporated gas compressed by the first compressor 120, The first valve 191, the second valve 192, the third valve 193, the fourth valve 194, the thirteenth valve 206, the fourteenth valve 207, and the first valve 191, The fifteenth valve 208 is opened and the fifth valve 195, the ninth valve 201 and the twelfth valve 205 are driven in a closed state.

When the evaporated gas compressed by the first compressor 120 after being discharged from the storage tank T is supplied to the recycle line L5 along the third additional line L12, the first valve 191 and the second valve The valve 192 is closed so that the evaporated gas flows through the first compressor 120, the first cooler 130, the fourteenth valve 207, the second heat exchanger 140, the refrigerant decompressor 160, To form a closed loop refrigerant cycle that circulates the compressor (140), the additional compressor (124), the additional cooler (134), and the thirteenth valve (206).

The refrigerant cycle of the ship of the present embodiment is operated in a closed loop, the evaporated gas compressed by the second compressor 122 is sent to the fuel consumer 180, the refrigerant cycle is compressed by the evaporated gas compressed by the first compressor 120, The flow of the evaporating gas will be described as follows.

The evaporated gas discharged from the storage tank T is compressed by the second compressor 122 after passing through the first heat exchanger 110 and cooled by the second cooler 132, And the remaining part is subjected to a liquefaction process along the return line L3 through the fifteenth valve 208. [

The evaporated gas that has passed through the first heat exchanger 110 after being discharged from the storage tank T may be approximately 1 bar and approximately 1 bar of evaporated gas is compressed by the second compressor 122 to approximately 17 bar . The pressure of the evaporated gas compressed by the second compressor 122 may vary depending on the re-liquefaction performance required by the system and the operating conditions of the system.

The evaporative gas passing through the re-liquefaction process along the return line L3 is compressed by the propulsion compressor 126 and cooled by the propulsion cooler 136 and then supplied to the storage tank T by the first heat exchanger 110. [ Exchanged with the evaporated gas discharged from the evaporator. The evaporated gas cooled by the first heat exchanger (110) is heat-exchanged in the second heat exchanger (140), is further cooled, and then expanded by the first decompressor (150) to partially or totally re-liquefy.

In the case where the ship of this embodiment does not include the gas-liquid separator 170, the evaporated gas partially or totally re-liquefied is directly sent to the storage tank T. When the ship of this embodiment includes the gas-liquid separator 170 The evaporated gas partially or totally re-liquefied is sent to the gas-liquid separator 170. The gas separated by the gas-liquid separator 170 is combined with the evaporated gas discharged from the storage tank T and sent to the first heat exchanger 110. The liquid separated by the gas-liquid separator 170 is supplied to the storage tank T).

On the other hand, the evaporative gas circulating in the refrigerant cycle is compressed further by the additional compressor 124 and cooled by the additional cooler 134, then further compressed by the first compressor 120 and further compressed by the first cooler 130 Cooled, passed through the fourteenth valve 207, and sent to the second heat exchanger 140 along the recycle line L5. The evaporated gas sent to the second heat exchanger 140 after passing through the additional compressor 124 and the first compressor 120 is firstly heat-exchanged and cooled by the second heat exchanger 140, So that it is expanded and cooled secondarily.

The evaporated gas compressed by the additional compressor 124 may be approximately 2 bar, and approximately 2 bar of evaporated gas may be compressed by the first compressor 120 to approximately 32 bar. The pressure of the evaporated gas compressed by the additional compressor 124 and the pressure of the evaporated gas compressed by the first compressor 120 may vary depending on the re-liquefaction performance required by the system and the operating conditions of the system.

The evaporated gas that has passed through the refrigerant decompressor 160 is again sent to the second heat exchanger 140 and then supplied to the second heat exchanger 140 along the return line L3 after passing through the first heat exchanger 110 Evaporated gas; And the evaporation gas compressed by the additional compressor 124 and the first compressor 120 and then supplied to the second heat exchanger 140 along the recycle line L5. The evaporated gas used as the refrigerant in the second heat exchanger 140 after passing through the refrigerant decompressor 160 is again sent to the additional compressor 124 and repeats the above-described series of processes.

The refrigerant cycle of the ship of the present embodiment is operated in a closed loop, the evaporated gas compressed by the second compressor 122 is sent to the fuel consumer 180, the refrigerant cycle is compressed by the evaporated gas compressed by the first compressor 120, The third valve 193, the fourth valve 194, the thirteenth valve 206, the fourteenth valve 207, and the seventh valve 207 when the second compressor 122 or the second cooler 132 fails, And the fifteenth valve 208 are closed and the first valve 191 and the second valve 192 are opened so that the evaporated gas that has passed through the first heat exchanger 110 after being discharged from the storage tank T, And is supplied to the fuel consumer 180 via the first valve 191, the first compressor 120, the first cooler 130, and the second valve 192.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. It is.

100a, 100b, 120: first compressors 200a, 200b, 110: first heat exchanger
300a, 300b: refrigerant circulation units 310a, 310b: refrigerant compressor
320a, 320b, 130: first cooler 330a, 330b, 160: refrigerant pressure reducing device
400a, 400b, 191 to 198, 201 to 203, 205 to 208: valves
500a, 500b, 140: second heat exchanger 600a, 600b, 150: first decompression device
700a, 700b, 170: gas-liquid separator 800a, 800b: second decompression device
122: second compressor 132: second cooler
124: additional compressor 134: additional cooler
126: propulsion compressor 136: propulsion cooler
180: Fuel Demand Source 900: Compressor

Claims (22)

In a vessel including a liquefied gas storage tank,
A first compressor capable of compressing at least a part of evaporative gas discharged from the storage tank;
A second compressor for compressing another portion of the evaporative gas discharged from the storage tank;
A propulsion compressor for compressing a part of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A refrigerant pressure reducing device for expanding another part of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A second heat exchanger that uses the fluid expanded by the refrigerant pressure reducing device as a refrigerant to cool the evaporated gas compressed by the propelling compressor;
An additional compressor for compressing the refrigerant having passed through the refrigerant decompressor and the second heat exchanger; And
And a first decompression device for compressing the fluid cooled in the second heat exchanger after being compressed by the propulsion compressor,
Wherein the additional compressor is driven by a power generated by the refrigerant pressure reducing device while expanding the fluid,
Wherein the additional compressor compresses the refrigerant that has passed through the second heat exchanger and sends it to the second compressor. The method according to claim 1,
Further comprising a first heat exchanger for cooling the evaporation gas compressed by the propulsion compressor by heat-exchanging the evaporation gas discharged from the storage tank with refrigerant,
The second heat exchanger further compresses the evaporated gas cooled by the first heat exchanger after being compressed by the propelling compressor,
Wherein the first decompressor expands the fluid cooled in the first heat exchanger and the second heat exchanger after being compressed by the propulsion compressor. In a vessel including a liquefied gas storage tank,
A first compressor capable of compressing at least a part of evaporative gas discharged from the storage tank;
A second compressor for compressing another portion of the evaporative gas discharged from the storage tank;
A propulsion compressor for compressing a part of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A refrigerant pressure reducing device for expanding another part of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A second heat exchanger that uses the fluid expanded by the refrigerant pressure reducing device as a refrigerant to cool the evaporated gas compressed by the propelling compressor;
An additional compressor for compressing the refrigerant having passed through the refrigerant decompressor and the second heat exchanger; And
And a first decompression device for compressing the fluid cooled in the second heat exchanger after being compressed by the propulsion compressor,
Wherein the additional compressor is driven by a power generated by the refrigerant pressure reducing device while expanding the fluid,
Wherein the additional compressor compresses the refrigerant that has passed through the second heat exchanger and sends it to the first compressor and the second compressor. The method of claim 3,
Further comprising a first heat exchanger for cooling the evaporation gas compressed by the propulsion compressor by heat-exchanging the evaporation gas discharged from the storage tank with refrigerant,
The second heat exchanger further compresses the evaporated gas cooled by the first heat exchanger after being compressed by the propelling compressor,
Wherein the first decompressor expands the fluid cooled in the first heat exchanger and the second heat exchanger after being compressed by the propulsion compressor. The method according to any one of claims 1 to 4,
The propulsion compressor compresses only the evaporated gas compressed by the first compressor,
Wherein the refrigerant pressure reducing device expands only the evaporated gas compressed by the second compressor. The method according to any one of claims 1 to 4,
Wherein the second heat exchanger is capable of cooling the fluid before passing through the refrigerant depressurizing device by the refrigerant expanded by the refrigerant depressurizing device. The method according to any one of claims 1 to 4,
Further comprising a gas-liquid separator for separating the liquefied gas and the evaporated gas from the fluid that has passed through the first decompression device,
And the liquefied gas separated from the gas-liquid separator is sent to the storage tank. The method according to any one of claims 1 to 4,
Wherein another portion of the evaporated gas compressed by at least one of the first compressor and the second compressor is supplied to the fuel consumer. The method according to any one of claims 1 to 4,
Wherein the refrigerant forms a closed loop refrigerant cycle that circulates through at least the additional compressor, the second compressor, the refrigerant decompressor, and the second heat exchanger. delete 1. An evaporative gas treatment system for a ship comprising a storage tank for storing liquefied gas,
A first supply line for compressing a part of the evaporation gas discharged from the storage tank by a first compressor and sending the compressed gas to a fuel demanding place;
A second supply line that branches from the first supply line and compresses another part of the evaporated gas discharged from the storage tank by a second compressor;
A return line branched from the first supply line, further compressing the compressed evaporated gas by a propulsion compressor, and then passing through the first heat exchanger, the second heat exchanger, and the first decompressor to re-
A recirculation line for passing the cooled evaporated gas through the second heat exchanger and the refrigerant decompression device to the second heat exchanger so as to be used as a refrigerant; And
And an additional compressor installed upstream of the second compressor to compress the evaporated gas,
Wherein the additional compressor is driven by a power generated by the refrigerant pressure reducing device while expanding the fluid,
Wherein the first heat exchanger is configured to cool the evaporation gas discharged from the storage tank as a refrigerant by heat exchange with the evaporation gas supplied through the return line after being compressed by the propulsion compressor,
Wherein the second heat exchanger includes: evaporative gas supplied through the recirculation line, the evaporation gas having passed through the refrigerant decompression device as a refrigerant; And an evaporation gas supplied along the return line are cooled by heat exchange,
Wherein the additional compressor compresses the refrigerant that has passed through the second heat exchanger and sends it to the second compressor or to the first compressor and the second compressor. The method of claim 11,
Wherein the additional compressor is installed on the second supply line. The method of claim 11,
Wherein said additional compressor is installed on said recirculation line downstream of said refrigerant depressurization device and said second heat exchanger. The method of claim 12,
And a first additional line connecting a recirculation line downstream of the refrigerant decompressor and the second heat exchanger and a second supply line upstream of the second compressor. 15. The method of claim 14,
Wherein after the evaporated gas has passed through said additional compressor, said second compressor, said second heat exchanger, said refrigerant decompression device and again said second heat exchanger, Wherein the vessel forms a refrigerant cycle of the vessel. 15. The method of claim 14,
The evaporated gas compressed by the first compressor and the evaporated gas compressed by the second compressor are combined,
Some are re-liquefied along the return line,
The other part of the refrigerant passes through the second heat exchanger, the refrigerant decompression device and again the second heat exchanger along the recirculation line, is merged with the fluid discharged from the storage tank and passed through the first heat exchanger,
And the remaining portion is supplied to the fuel demanding site. 15. The method of claim 14,
A part of the evaporated gas compressed by the first compressor is re-liquefied along the return line, and the remaining part is supplied to the fuel demanding place,
Wherein the evaporated gas compressed by the second compressor passes through the second heat exchanger, the refrigerant decompressor, and again the second heat exchanger along the recirculation line, and then is discharged from the storage tank and flows into the first heat exchanger Wherein the vapor is combined with the passed fluid. 14. The method of claim 13,
Wherein the refrigerant cycle forms a closed-loop refrigerant cycle in which evaporated gas circulates through the second compressor, the second heat exchanger, the refrigerant depressurization device, the second heat exchanger, and the additional compressor. 1. An evaporative gas treatment system for a ship comprising a storage tank for storing liquefied gas,
A first supply line for compressing a part of the evaporation gas discharged from the storage tank by a first compressor and sending the compressed gas to a fuel demanding place;
A second supply line that branches from the first supply line and compresses another part of the evaporated gas discharged from the storage tank by a second compressor;
A return line branching from the first supply line, further compressing the compressed evaporated gas by a propulsion compressor, and then passing through a second heat exchanger and a first decompression device to re-liquefy;
A recirculation line for passing the cooled evaporated gas through the second heat exchanger and the refrigerant decompression device to the second heat exchanger so as to be used as a refrigerant;
An additional compressor installed upstream of the second compressor to compress the evaporated gas;
A second addition line branching from the recycle line downstream of the further compressor and connected to the first supply line upstream of the first compressor;
A third addition line branching from a first supply line downstream of the first compressor and connected to a recirculation line upstream of the refrigerant decompressor and the second heat exchanger; And
And a fourth additional line that branches from a second supply line downstream of the second compressor and is connected to the return line upstream of the propulsion compressor,
Wherein the additional compressor is driven by a power generated by the refrigerant pressure reducing device while expanding the fluid,
Wherein the second heat exchanger includes: evaporative gas supplied through the recirculation line, the evaporation gas having passed through the refrigerant decompression device as a refrigerant; And an evaporation gas supplied along the return line are cooled by heat exchange,
Wherein said additional compressor is installed on said recirculation line downstream of said refrigerant depressurization device and said second heat exchanger. The method of claim 19,
After the evaporation gas has been compressed by the second compressor, the refrigerant passes through the second heat exchanger, the refrigerant decompression device, the second heat exchanger, and the additional compressor again along the recirculation line and back to the second compressor Wherein the refrigerant cycle of the closed loop of the ship is supplied. The method of claim 19,
The evaporated gas is compressed by the first compressor and then supplied to the second heat exchanger along the third additional line and the recirculation line and passes through the refrigerant depressurization device again the second heat exchanger and the additional compressor Wherein the second additional line is fed back to the first compressor along the second additional line to form a closed loop refrigerant cycle. The method according to any one of claims 19 to 21,
Wherein the return line further compresses the compressed evaporated gas by the propulsion compressor and then passes through the first heat exchanger, the second heat exchanger, and the first decompressor to re-
Wherein the first heat exchanger uses the evaporated gas discharged from the storage tank as a refrigerant to heat the evaporated gas supplied through the return line after being compressed by the propelling compressor to cool the evaporated gas.

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