JP6204609B2 - Ship - Google Patents

Description

  The present invention relates to a marine vessel, and more particularly, to a marine vessel equipped with a system for re-liquefying an evaporative gas generated inside a storage tank and remaining as an engine fuel.

  In recent years, the consumption of liquefied gas such as liquefied natural gas (liquefied natural gas, LNG) has been increasing rapidly worldwide. The liquefied gas obtained by liquefying the gas at a low temperature has an advantage that the storage and transfer efficiency is improved because the volume is greatly reduced as compared with the gas. In addition, liquefied gas such as liquefied natural gas is an environmentally friendly fuel that can remove and reduce air pollutants during the liquefaction process and emits less air pollutants during combustion.

  The liquefied natural gas is a colorless and transparent liquid obtained by cooling and liquefying natural gas mainly composed of methane to about −162 ° C., and has a volume of about 1/600 compared with natural gas. Become. Therefore, if natural gas is liquefied and transferred, very efficient transfer is possible.

  However, the liquefaction temperature of natural gas is an extremely low temperature of −162 ° C. at normal pressure, and liquefied natural gas is sensitive to temperature changes and thus evaporates immediately. Therefore, the storage tank that stores the liquefied natural gas is thermally insulated, but external heat is continuously transmitted to the storage tank, and the liquefied natural gas is continuously transferred in the storage tank during the transportation of the liquefied natural gas. Naturally vaporized and evaporative gas (Boil-Off Gas, BOG) is generated. The same applies to other low-temperature liquefied gases such as ethane.

  Evaporative gas is one of the losses and is an important issue in transportation efficiency. In addition, if evaporative gas accumulates in the storage tank, the tank internal pressure increases excessively, and in an extreme case, the tank may be damaged. Therefore, various methods for treating the evaporative gas generated in the storage tank have been studied. Recently, for evaporative gas treatment, the evaporative gas is re-liquefied and returned to the storage tank. The method of using as an energy source of fuel consumption destinations, such as an engine, is used.

  The method for re-liquefying the evaporative gas includes a refrigeration cycle using another refrigerant, a method for re-liquefying the evaporative gas by exchanging heat with the refrigerant, and a method for re-liquefying the evaporative gas itself as a refrigerant without another refrigerant. There are methods. In particular, a system that employs the latter method is referred to as a partial re-liquefaction system (PRS).

  Among general engines used in ships, engines that can use natural gas as fuel include gas fuel engines such as DFDE and ME-GI engines.

  DFDE is a four-stroke engine, adopting an Otto Cycle that injects natural gas having a relatively low pressure of about 6.5 bar into the combustion air inlet and compresses the piston as it goes up. Yes.

  The ME-GI engine is a two-stroke engine and employs a diesel cycle in which high-pressure natural gas of nearly 300 bar is directly injected into the combustion chamber near the top dead center of the piston. Recently, there has been a growing interest in ME-GI engines with better fuel efficiency and propulsion efficiency.

  An object of this invention is to provide the ship provided with the system which can exhibit the evaporative gas reliquefaction performance improved compared with the conventional partial reliquefaction system.

  According to one embodiment of the present invention for achieving the above object, in a ship having 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 part of the evaporated gas discharged from the tank; a part of the evaporated gas compressed by at least one of the first compressor and the second compressor is compressed. A propulsion compressor that performs heat exchange between the evaporative gas compressed by the propulsion compressor and the evaporative gas discharged from the storage tank; at least one of the first compressor and the second compressor A refrigerant decompression device that expands another part of the evaporated gas compressed by one of the above; a fluid expanded by the refrigerant decompression device as a refrigerant, compressed by the propulsion compressor, and A second heat exchanger that cools the evaporative gas heat-exchanged by the heat exchanger; an additional compressor that compresses the refrigerant that has passed through the refrigerant decompression device and the second heat exchanger; A first pressure reducing device that expands the fluid cooled by the first heat exchanger and the second heat exchanger; and the additional compressor is driven by the power that the refrigerant pressure reducing device produces while expanding the fluid. A ship characterized by the above is provided.

  The propulsion compressor can compress only the evaporated gas compressed by the first compressor, and the refrigerant decompression device can expand only the evaporated gas compressed by the second compressor.

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

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

  The propulsion compressor compresses a part of the evaporated gas compressed by the first compressor and the second compressor, and the refrigerant decompression device compresses by the first compressor and the second compressor. The other part in the evaporated gas can be expanded.

  The evaporative gas sent to the second heat exchanger first passes through the second heat exchanger and is expanded by the refrigerant decompression device, and then sent to the second heat exchanger again. The fluid that is expanded by the refrigerant decompression device and used as the refrigerant in the refrigerant decompression device is a fluid sent to the second heat exchanger before passing through the refrigerant decompression device; compressed by the propulsion compressor Both the evaporative gas cooled by the first heat exchanger can be cooled.

  The ship passes through the propulsion compressor, the first heat exchanger, the second heat exchanger, and the first pressure reducing device, and partially liquefied liquefied gas and evaporated gas remaining in a gaseous state. The gas-liquid separator can be further provided. 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 is the first heat. Can be sent to the exchanger.

  A part of the evaporative gas sent to the propulsion compressor may be branched upstream of the propulsion compressor and supplied at a fuel demand destination.

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

  According to another embodiment of the present invention for achieving the above object, in a ship having a liquefied gas storage tank, a first compressor capable of compressing at least part of the evaporated gas discharged from the storage tank; A second compressor for compressing another part of the evaporated gas discharged from the storage tank; a part of the evaporated gas compressed by at least one of the first compressor and the second compressor; A propulsion compressor that compresses; a refrigerant decompression device that expands another part of the evaporated gas compressed by at least one of the first compressor and the second compressor; expanded by the refrigerant decompression device; A second heat exchanger that cools the evaporated gas compressed by the propulsion compressor; and an additional compressor that compresses the refrigerant that has passed through the refrigerant decompression device and the second heat exchanger; A first pressure reducing device that expands the fluid cooled by the second heat exchanger after being compressed by the compressor; and the additional compressor is powered by the power that the refrigerant pressure reducing device produces while expanding the fluid. A ship characterized in that it is driven is provided.

  According to another embodiment of the present invention for achieving the above object, in an evaporative gas treatment system for a ship having a storage tank for storing liquefied gas, a part of the evaporative gas discharged from the storage tank is removed. A first supply line that is compressed by the first compressor and then sent to a fuel demand destination; another part of the evaporated gas that is branched from the first supply line and discharged from the storage tank is compressed by the second compressor The second supply line; the compressed evaporative gas branched from the first supply line is further compressed by the propulsion compressor, and then passed through the first heat exchanger, the second heat exchanger, and the first pressure reducing device. A return line for re-liquefaction; a recirculation line for passing evaporative gas cooled by passing through the second heat exchanger and the refrigerant pressure reducing device to the second heat exchanger and using it as a refrigerant; and the second compressor Upstream of An additional compressor installed to compress the evaporative gas, wherein the additional compressor is driven by the power produced by the refrigerant decompression device while expanding the fluid, and the first heat exchanger is discharged from the storage tank. The evaporated gas used as a refrigerant is cooled by exchanging heat of the evaporated gas compressed by the propulsion compressor and supplied along the return line, and the second heat exchanger converts the evaporated gas that has passed through the refrigerant decompression device. An evaporative gas treatment system for a ship, wherein both the evaporative gas supplied along the recirculation line and the evaporative gas supplied along the return line are cooled by exchanging heat as refrigerant. Is provided.

  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 decompression device and the second heat exchanger.

  The evaporative gas treatment system of the ship includes a first additional line connecting between the refrigerant decompression device and a recirculation line downstream of the second heat exchanger and a second supply line upstream of the second compressor. Can be provided.

  The evaporative gas processing system of the ship is configured such that the evaporative gas passes through the additional compressor, the second compressor, the second heat exchanger, the refrigerant decompression device, and the second heat exchanger again, and then the first It is possible to form a closed-loop refrigerant cycle that is supplied to the additional compressor again via an additional line.

  The evaporative gas compressed by the first compressor and the evaporative gas compressed by the second compressor merge, a part is reliquefied along the return line, and the other part is the recirculation line. Along the second heat exchanger, the refrigerant pressure reducing device and the second heat exchanger again, and then merged with the fluid discharged from the storage tank and passed through the first heat exchanger, and the remaining A portion can be supplied to the fuel consumer.

  The evaporative gas compressed by the first compressor is partially liquefied along the return line, and the remaining part is supplied at the fuel demand destination and is evaporated by the second compressor. After passing through the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger again along the recirculation line, the gas is discharged from the storage tank and passes through the first heat exchanger. Can merge with fluid.

  The ship's evaporative gas processing system has a closed-loop refrigerant cycle in which evaporative gas circulates through the second compressor, the second heat exchanger, the refrigerant decompression device, the second heat exchanger, and the additional compressor again. Can be formed.

  The ship's evaporative gas treatment system branches from a recirculation line downstream of the additional compressor and is connected to the first supply line upstream of the first compressor; the first compression line; A third additional line branched from a first supply line downstream of the machine and connected to a recirculation line upstream of the refrigerant decompression device and the second heat exchanger; a second supply downstream of the second compressor A fourth additional line branched from the line and connected to the return line upstream of the propulsion compressor.

  The evaporative gas processing system of the ship has the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger again along the recirculation line after the evaporative gas is compressed by the second compressor. In addition, a closed-loop refrigerant cycle that passes through the additional compressor and is supplied to the second compressor again can be formed.

  The evaporative gas treatment system of the ship is configured such that after evaporating gas is compressed by the first compressor, the evaporative gas is supplied to the second heat exchanger along the third additional line and the recirculation line, and the refrigerant A closed loop refrigerant cycle may be formed which passes through the decompression device, the second heat exchanger and the additional compressor again and is supplied again to the first compressor along the second additional line.

  According to another embodiment of the present invention for achieving the object, the evaporative gas discharged from the liquefied gas storage tank is branched in two, and the flow of any of the branched evaporative gas is: Compressed by the first compressor, the other flow is compressed by the second compressor, and the evaporated gas compressed by the first compressor is further compressed by the propulsion compressor and then re-liquefied and returned to the storage tank The evaporative gas compressed by the second compressor is used as a refrigerant for circulating the refrigerant cycle to cool the evaporative gas compressed by the first compressor, and the fluid circulating in the refrigerant cycle is: A method is provided that is compressed by an additional compressor and then fed to the second compressor.

  Compared with the existing partial reliquefaction system (PRS), the present invention increases the reliquefaction efficiency and reliquefaction amount because the evaporated gas is decompressed after undergoing an additional cooling process by the second heat exchanger. be able to. In particular, it is economical because most or all of the remaining evaporative gas can be reliquefied without using a refrigeration cycle that uses another refrigerant.

  In addition, according to the present invention, it is possible to fluidly control the refrigerant flow rate and the cold supply according to the discharge amount of evaporative gas, the engine load depending on the ship operating speed, and the like.

  According to one embodiment of the present invention, the pre-compressor that has already been installed is used to increase the re-liquefaction efficiency and re-liquefaction amount, thereby contributing to securing the space on board and reducing the installation cost of the additional compressor. can do. In particular, not only the evaporative gas compressed by the precompressor but also the evaporative gas compressed by the main compressor can be used as a refrigerant in the second heat exchanger and used as a refrigerant in the second heat exchanger. Since the flow rate of the evaporation gas can be increased, the reliquefaction efficiency and the reliquefaction amount can be further increased.

  According to another embodiment of the present invention, since the mass of the fluid used as the refrigerant in the second heat exchanger becomes larger after being compressed by the second compressor, the reliquefaction efficiency in the second heat exchanger is increased. It is possible to increase the amount of liquefaction and to use the power produced by the refrigerant decompression device.

  In addition, the present invention can further include a propulsion compressor to increase the pressure of the evaporative gas passing through the reliquefaction process, thereby further increasing the reliquefaction efficiency and the reliquefaction amount.

It is the block diagram which showed the conventional partial reliquefaction system schematically. It is the block diagram which showed roughly the evaporative gas processing system of the ship which concerns on 1st Example of this invention. It is the block diagram which showed roughly the evaporative gas processing system of the ship which concerns on 2nd Example of this invention. It is the block diagram which showed roughly the evaporative gas processing system of the ship which concerns on 3rd Example of this invention. It is the block diagram which showed roughly the evaporative gas processing system of the ship which concerns on 4th Example of this invention. It is the block diagram which showed roughly the evaporative gas processing system of the ship which concerns on 5th Example of this invention. It is the block diagram which showed roughly the evaporative gas processing system of the ship which concerns on 6th Example of this invention. It is the graph which showed roughly the phase change of methane by temperature and pressure. It is the graph which showed each temperature of methane by a heat flow under different pressure conditions.

  Hereinafter, the configuration and operation of a preferred embodiment 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 and applications such as a ship equipped with an engine using natural gas as fuel and a ship equipped with a liquefied gas storage tank. The following examples can be modified in various forms, and the scope of the present invention is not limited to the following examples.

  The evaporative gas treatment system of the present invention to be described later includes all kinds of ships and offshore structures equipped with storage tanks capable of storing cryogenic liquid cargo or liquefied gas, that is, liquefied natural gas carriers, liquefied ethane gas (Liquid Ethane). Gas) It can be applied to marine structures such as LNG-FPSO and LNG-FSRU, as well as ships such as LNG carrier and LNG-RV. However, in the examples described later, for the sake of explanation, liquefied natural gas of a typical cryogenic liquid cargo will be described as an example.

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

  FIG. 1 is a configuration diagram schematically showing a conventional partial reliquefaction system.

  Referring to FIG. 1, in a conventional partial reliquefaction system, evaporative gas generated and discharged in a storage tank for storing liquid cargo is transferred along a pipe and compressed by an evaporative gas compression unit (10). .

  The storage tank (T) has a hermetic barrier and a heat insulating barrier so that liquefied gas such as liquefied natural gas can be stored in a cryogenic state, but cannot completely block heat transferred from the outside, The evaporation of liquefied gas continues in the tank, and the tank internal pressure may increase. However, in order to prevent an excessive increase in the tank pressure due to such evaporative gas and maintain an appropriate level of pressure resistance, The evaporative gas is discharged and supplied to the evaporative gas compression section (10).

  The evaporative gas discharged from the storage tank and compressed by the evaporative gas compression unit (10) is referred to as a first stream, the first stream of compressed evaporative gas is divided into a second stream and a third stream, and the second stream is The third stream can be configured to be liquefied and returned to the storage tank (T), and the third stream can be configured to be supplied to a gas fuel consumption destination such as a propulsion engine or a power generation engine in the ship. In this case, the evaporative gas compression unit (10) can compress the evaporative gas up to the supply pressure of the fuel consumption destination, and the second stream is branched through all or part of the evaporative gas compression unit as necessary. Can do. Depending on the fuel requirement of the fuel consumption destination, all of the evaporated gas compressed into the third stream can be supplied, and the entire amount of the evaporated gas compressed into the second stream is supplied to the storage tank. It can also be restored. Gas fuel is consumed by high-pressure gas injection engines (for example, ME-GI engine developed by MDT) and low-pressure gas injection engines (for example, X-DF engine (Generation X-Dual Fuel engine) of Wartsila). First, DF-Generator, gas turbine, DFDE, etc. can be mentioned as examples.

  At this time, a heat exchanger (20) is installed so that the second stream of the compressed evaporative gas can be liquefied, and the evaporative gas generated from the storage tank is used as a cold heat source for the compressed evaporative gas. To do. The compressed evaporative gas whose temperature in the compression process of the evaporative gas compression unit has increased through the heat exchanger (20), that is, the second stream is cooled, generated in the storage tank, and introduced into the heat exchanger (20). The evaporated gas is heated and supplied to the evaporated gas compression section (10).

  Since the flow rate of the evaporative gas before compression is higher than the flow rate of the second stream, the second stream of compressed evaporative gas can be supplied with cold heat from the evaporative gas before compression, and at least partly liquefy. Thus, in the heat exchanger, the high-temperature evaporative gas is liquefied by exchanging heat between the low-temperature evaporative gas immediately after being discharged from the storage tank and the high-pressure evaporative gas compressed by the evaporative gas compression unit.

  The evaporated gas of the second stream that has passed through the heat exchanger (20) is further cooled while being reduced in pressure while passing through expansion means (30) such as an expansion valve and an expander, and is supplied to the gas-liquid separator (40). . The liquefied evaporative gas is separated into a gas component and a liquid component by a gas-liquid separator, the liquid component, ie, liquefied natural gas, returns to the storage tank, and the gas component, ie, evaporative gas, is discharged from the storage tank. And merged with the flow of the evaporative gas supplied to the heat exchanger (20) and the evaporative gas compressor (10), or supplied again to the heat exchanger (20) and compressed by the evaporative gas compressor (10). It can also be used as a cold heat source for exchanging heat of the high pressure vapor. Of course, it can be sent to a gas combustion unit (GCU) or the like and burned, or sent to a gas consumer (including a gas engine) to be consumed. In order to further depressurize the gas separated by the gas-liquid separator before joining the flow of the evaporating gas, another expansion means (50) can be installed.

  FIG. 2 is a block diagram schematically showing an evaporative gas treatment system for a ship according to a first embodiment of the present invention.

  Referring to FIG. 2, the system of the present embodiment receives a supply of evaporative gas (Boil Off Gas) generated from low-temperature liquid cargo stored in a storage tank, and circulates the evaporative gas as a refrigerant. It is characterized by comprising.

  For this reason, a refrigerant supply line (CSLa) for supplying evaporative gas from the storage tank to the refrigerant circulation part (300a) is provided, and a valve (400a) is provided in the refrigerant supply line so that a sufficient amount can be circulated through the refrigerant circulation part. When the evaporative gas is supplied, the refrigerant supply line (CSLa) is shut off, and the refrigerant circulation part (300a) is operated in a closed loop.

  Similar to the basic embodiment described above, the first expansion embodiment is also provided with a first compressor (100a) that compresses the evaporative gas generated from the cryogenic liquid cargo in the storage tank (T). The evaporative gas generated in the storage tank is introduced into the first compressor (100a) along the evaporative gas supply line (BLa).

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

  On the other hand, in the present embodiment, only the line for reliquefying the evaporative gas is shown, but the evaporative gas compressed by the first compressor (100a) is the propulsion engine and power generation engine of the ship or offshore structure. When the fuel consumption can be consumed as a fuel and the fuel consumption can consume the entire amount of evaporative gas, there may be no reliquefied evaporative gas. When the consumption of gas fuel is small, such as when the ship is anchored, the entire amount of evaporative gas can be supplied to the evaporative gas reliquefaction line (RLa).

  The compressed evaporated gas is supplied to the first heat exchanger (200a) along the evaporated gas reliquefaction line (RLa), and the first heat exchanger (200a) is supplied to the evaporated gas reliquefaction line (RLa) and the evaporated gas supply. Heat is exchanged between the evaporated gas provided over the line (BLa) and introduced into the first compressor (100a) and the evaporated gas compressed through at least a part of the first compressor (100a). The evaporative gas whose temperature has increased in the compression process is cooled through heat exchange with the low-temperature evaporative gas generated in the storage tank and introduced into the first compressor (100a).

  A second heat exchanger (500a) is provided downstream of the first heat exchanger (200a), and the evaporated gas that has been compressed and heat-exchanged by the first heat exchanger (200a) is supplied to the refrigerant circulation section (300a). ) Is further cooled through heat exchange with the evaporative gas circulating in the air.

  The refrigerant circulation unit (300a) includes a refrigerant compressor (310a) that compresses the evaporative gas supplied from the storage tank, a first cooler (320a) that cools the evaporative gas compressed by the refrigerant compressor, And a refrigerant decompression device (330a) for decompressing the evaporative gas cooled by the cooler (320a) and further cooling it. The refrigerant decompression device (330a) may be an expansion valve or an expander that adiabatically expands and cools the evaporated gas.

  The evaporative gas cooled through the refrigerant decompression device (330a) is supplied to the second heat exchanger (500a) as a refrigerant along the refrigerant circulation line (CCLa), and the first heat exchanger (500a) The evaporative gas is cooled through heat exchange with the evaporative gas supplied through the heat exchanger (200a). The evaporative gas in the refrigerant circulation line (CCLa) that has passed through the second heat exchanger (500a) is circulated to the refrigerant compressor (310a), and circulates through the refrigerant circulation line through the compression and cooling processes described above.

  On the other hand, the evaporative gas in the evaporative gas reliquefaction line (RLa) cooled by the second heat exchanger (500a) is depressurized via the first depressurization device (600a). The first decompressor (600a) can be an expansion valve or expander, such as a Joule-Thomson valve.

  The decompressed evaporative gas is supplied to the gas-liquid separator (700a) downstream of the first decompression device (600a) for gas-liquid separation, and the liquid separated by the gas-liquid separator (700a), that is, liquefied natural gas. Is supplied to the storage tank (T) and stored again.

  The gas separated by the gas-liquid separator (700a), that is, the evaporating gas is further reduced in pressure through the second decompression device (800a), and is introduced from the storage tank (T) into the first heat exchanger (200a). It can also be used as a cold supply source that merges with the flow of the evaporative gas or heat-exchanges the high-pressure evaporative gas that is supplied to the first heat exchanger (200a) and compressed by the first compressor (100a) again. it can. Of course, it can be sent to a gas combustion unit (GCU) or the like for combustion, or sent to a fuel demand destination (including a gas engine) for consumption.

  FIG. 3 is a configuration diagram schematically showing an evaporative gas treatment system for a ship according to a second embodiment of the present invention.

  Referring to FIG. 3, in this example, the refrigerant circulating part (300b) reduced the evaporation gas introduced from the first cooler (320b) to the refrigerant pressure reducing device (330b) by the refrigerant pressure reducing device (330b). After cooling by evaporating gas and heat exchange, the refrigerant is supplied to the refrigerant decompression device (330b).

  Since the evaporative gas is cooled while being depressurized via the refrigerant depressurization device (330b), the temperature of the evaporative gas downstream of the refrigerant depressurization device is lower than that of the evaporative gas upstream of the refrigerant depressurization device. Considering this, the evaporative gas upstream of the refrigerant decompression device is cooled by exchanging heat with the downstream evaporative gas and then introduced into the decompression device. For this reason, as shown in FIG. 3, the evaporative gas upstream of the refrigerant pressure reducing device (330b) can be supplied to the second heat exchanger (500b) (part A in FIG. 3). If necessary, another heat exchange device capable of exchanging heat between the evaporative gas upstream and downstream of the refrigerant decompression device can be additionally configured.

  As described above, the system of the present embodiment can re-liquefy and store the evaporative gas generated from the liquid cargo in the storage tank, so that the transportation rate of the liquid cargo can be increased. It is possible to reduce the amount of cargo that is wasted by burning with a gas combustion unit (GCU), etc., in order to prevent an increase in the pressure of the storage tank, especially when the amount of fuel consumed by the ship's gas consumer is small. Therefore, waste of energy can be prevented.

  Moreover, by evaporating the evaporative gas as a refrigerant and utilizing it as a cold heat source for reliquefaction of the evaporative gas, the evaporative gas can be effectively reliquefied without configuring another refrigerant cycle, Since it is not necessary to supply a separate refrigerant, it contributes to securing space in the ship and is economical. Further, when there is not enough refrigerant in the refrigerant cycle, it can be replenished from the storage tank, smooth refrigerant replenishment is performed, and the refrigerant cycle can be effectively operated.

  As described above, the evaporative gas can be re-liquefied by using the cold heat of the evaporative gas itself in multiple stages, so the configuration of the in-vessel evaporative gas processing system can be simplified and a complex evaporative gas processing apparatus can be used. Installation and operation costs can be reduced.

  FIG. 4 is a configuration diagram schematically showing an evaporative gas treatment system for a ship according to a third embodiment of the present invention.

  Referring to FIG. 4, the ship according to the present embodiment includes a first heat exchanger (110) installed downstream of the storage tank (T); a storage tank installed downstream of the first heat exchanger (110). A first compressor (120) and a second compressor (122) for compressing the evaporated gas discharged from (T); a first cooler for lowering the temperature of the evaporated gas compressed by the first compressor (120) ( 130); 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 cooler (130); a third valve (193) installed upstream of the second compressor (122); and installed downstream of the second cooler (132). The fourth valve (194); by the first heat exchanger (110) Second heat exchanger (140) for further cooling the cooled evaporative gas; Refrigerant decompression sent to the second heat exchanger (140) again after expanding the evaporative gas that has passed through the second heat exchanger (140) And a first pressure reducing device (150) for expanding the evaporated gas further cooled by the second heat exchanger (140).

  The evaporative gas naturally generated and discharged in the storage tank (T) is supplied to the fuel demand destination (180) along the first supply line (L1). The first heat exchanger (110) is installed in the first supply line (L1), and collects cold heat from the evaporated gas immediately after being discharged from the storage tank (T). The ship in the present embodiment may further include an eleventh valve (203) that is installed upstream of the fuel demand destination (180) and adjusts the flow rate and opening / closing of the evaporative gas sent to the fuel demand destination (180). .

  The first heat exchanger (110) receives the supply of the evaporative gas discharged from the storage tank (T), and converts the evaporative gas supplied to the first heat exchanger (110) along the return line (L3). Used as a cooling refrigerant. A fifth valve (195) for adjusting the flow rate and opening / closing of the evaporating gas may be installed on the return line (L3).

  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) branches from the first supply line (L1) upstream of the first compressor (120) and is connected to the first supply line (L1) downstream of the first compressor (120). The In addition, the first compressor (120) and the second compressor (122) may be installed in parallel and have the same performance.

  In general, ships are additionally provided with a second compressor (122) and a second cooler (132) in case the first compressor (120) and the first cooler (130) fail. To do. Conventionally, the second compressor (122) and the second cooler (132) are not used during normal times when the first compressor (120) or the first cooler (130) is not broken.

  That is, conventionally, in the normal state in which the first compressor (120) or the first cooler (130) has not failed, the third valve (193) upstream of the second compressor (122) and the second cooler ( 132), the fourth valve (194) downstream is closed, and the evaporated gas passes through the first compressor (120) and the first cooler (130) and is supplied to the fuel demand destination (180). If the first compressor (120) or the first cooler (130) fails, the third valve (193) upstream of the second compressor (122) and the downstream of the second cooler (132). The fourth valve (194) of the first compressor (120) is opened, the first valve (191) upstream of the first compressor (120) and the second valve (192) downstream of the first cooler (130) are closed, and the evaporated gas Passes through the second compressor (122) and the second cooler (132) to the fuel demand destination (1 0) were configured to be supplied to.

  The present invention uses the second compressor (122) and the second cooler (132) that have not been used despite being installed in a conventional ship, and increases the reliquefaction efficiency and reliquefaction amount of the evaporated gas. The evaporative gas compressed by the second compressor (122) is partly sent to the fuel consumer (180), and the other part is evaporative gas in the second heat exchanger (140). Is used as a refrigerant for further cooling.

  FIG. 8 is a graph schematically showing the phase change of methane due to temperature and pressure. Referring to FIG. 8, methane enters a supercritical fluid state at temperatures above about −80 ° C. and pressure conditions above about 55 bar. That is, in the case of methane, a state of about −80 ° C. and 55 bar becomes a critical point. The state of the supercritical fluid is a third state different from the liquid state or the gas state.

  In addition, when the pressure is higher than the critical point and the temperature is lower than the critical point, it can be in a state similar to the high-density supercritical fluid state, which is different from the general liquid state. Hereinafter, the state of the evaporated gas having a temperature below the point is referred to as a “high pressure liquid state”.

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

  When the evaporated gas sent to the first heat exchanger (110) via the return line (L3) is in a gaseous state, the temperature of the evaporated gas decreases while passing through the first heat exchanger (110). Thus, the liquid and gas can be mixed, and in the case of the supercritical fluid state, the temperature can be lowered while passing through the first heat exchanger (110), and the “high pressure liquid state” can be obtained. .

  The evaporative gas cooled by the first heat exchanger (110) has a lower temperature while passing through the second heat exchanger (140), but the evaporative gas that has passed through the first heat exchanger (110) is liquid. When the gas is in a mixed state of gas and gas, the temperature of the evaporative gas becomes lower while passing through the second heat exchanger (140) and becomes a mixed state or liquid state in which the ratio of liquid is higher. In the “liquid state”, the temperature becomes lower while passing through the second heat exchanger (140).

  In addition, even when the evaporative gas that has passed through the second heat exchanger (140) is in the “high pressure liquid state”, the evaporative gas decreases in pressure while passing through the first decompression device (150), It becomes a mixed state of liquid and gas.

  Even if the pressure of the evaporative gas is reduced to the same level (P in FIG. 8) by the first pressure reducing device (150), the temperature is lower than when the pressure is reduced in a high temperature state (X → X ′ in FIG. 8). When the pressure is reduced in the state (Y → Y ′ in FIG. 8), the liquid is in a mixed state with a higher ratio. In addition, if the temperature can be further lowered, it is theoretically possible to reliquefy the evaporated gas 100% (Z → Z ′ in FIG. 8). Therefore, if the evaporative gas is cooled once more by the second heat exchanger (140) before passing through the first pressure reducing device (150), the reliquefaction efficiency and the reliquefaction amount are increased.

  Referring to FIG. 4, in the present embodiment, the refrigerant circulation portion (300a, 300b) for further cooling the evaporative gas in the first embodiment and the second embodiment is configured as a closed loop. The difference is that the cycle is configured in an open loop.

  In the first embodiment and the second embodiment, the refrigerant circulation section (300a, 300b) is configured in a closed loop, and the evaporated gas compressed by the refrigerant compressor (310a, 310b) is sent to the second heat exchanger (500a, 500b). ), It is impossible to send it to a fuel demander and go through a reliquefaction process.

  On the other hand, in this embodiment, the refrigerant cycle is configured in an open loop, and the evaporative gas compressed by the second compressor (122) merges with the evaporative gas compressed by the first compressor (120), and then merges. A part of the evaporated gas is sent to the fuel demand destination (180), the other part is used as the refrigerant of the second heat exchanger (140) along the recirculation line (L5), and the remaining part is A liquefaction process is performed along the return line (L3).

  The recirculation line (L5) branches from the first supply line (L1) downstream of the first compressor (120) and is connected to the first supply line (L1) upstream of the first compressor (120). Line. A sixth valve (196) for adjusting the flow rate and opening / closing of the evaporative gas is provided on the recirculation line (L5) through which the evaporative gas branched from the first supply line (L1) is sent to the second heat exchanger (140). Can be installed.

  In the present embodiment in which the refrigerant cycle is configured in an open loop, the downstream line of the first compressor (120) and the second compressor (122) are compared with the first and second embodiments in which the refrigerant cycle is configured in a closed loop. ) In that the downstream line is connected. That is, in this embodiment, the second supply line (L2) downstream of the second compressor (122) is connected to the first supply line (L1) downstream of the first compressor (120), and the second compression line (L1) is connected. After the evaporative gas compressed by the compressor (122) merges with the evaporative gas compressed by the first compressor (120), the second heat exchanger (140), the fuel demand destination (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, not only the evaporative gas compressed by the first compressor (120) but also the demand from the fuel demand destination (180) increases, such as an increase in ship operating speed. The evaporative gas compressed by the second compressor (122) can also be sent to the fuel customer (180).

  However, in general, the first compressor (120) and the second compressor (122) are designed to have a capacity of about 1.2 times the amount required by the fuel consumer (180). Therefore, it is rarely necessary to send the evaporated gas compressed by the second compressor (122) beyond the capacity of the first compressor (120) to the fuel demand destination (180). Rather, the evaporative gas discharged from the storage tank (T) cannot be consumed entirely at the fuel customer (180), and the evaporative gas that must be reliquefied increases, so that a large amount of evaporative gas can be reliquefied. More often, large amounts of refrigerant are required.

  According to this embodiment, not only the evaporative gas compressed by the compressor (120) but also the evaporative gas compressed by the second compressor (122) is used as the heat exchange refrigerant in the second heat exchanger (140). Since the evaporative gas supplied to the second heat exchanger (140) along the return line (L3) through the first heat exchanger (110) can be used, more refrigerant is used. Thus, the temperature can be cooled to a lower temperature, the overall reliquefaction efficiency and the reliquefaction amount can be increased, and it is theoretically possible to reliquefy 100%.

  In general, when determining the capacity of the compressors (120, 122) installed in the ship, the capacity required for supplying evaporative gas to the fuel demand destination (180) and all of the fuel demand destination (180) Considering the capacity required to reliquefy the remaining evaporated gas that cannot be consumed, according to this embodiment, the second compressor (122) is used to increase the reliquefaction amount. Therefore, the capacity required for reliquefaction can be reduced, and a small capacity compressor (120, 122) can be installed. If the capacity of the compressor is reduced, the cost for installing and operating the apparatus can be reduced.

  In the present embodiment, not only the first valve (191) and the second valve (192) but also the third valve (in the normal state where the first compressor (120) or the first cooler (130) has not failed. 193) and the fourth valve (194) are also opened to operate all of the first compressor (120), the first cooler (130), the second compressor (122), and the second cooler (132). When the first compressor (120) or the first cooler (130) fails, it is abandoned to increase the reliquefaction efficiency and the reliquefaction amount, and the first valve (191) and the second valve (192) are closed. Thus, the system is operated only with the evaporated gas that has passed through the second compressor (122) and the second cooler (132).

  For convenience of explanation, the first compressor (120) and the first cooler (130) play a main role, and the second compressor (122) and the second cooler (132) play an auxiliary role. As described above, the first compressor (120) and the second compressor (122), the first cooler (130) and the second cooler (132) perform the same role, and play the same role for one ship. A plurality of compressors and coolers are provided, and if one of them fails, the redundancy concept is satisfied in that it can be replaced with other equipment. The same applies hereinafter.

  Therefore, even when the second compressor (122) or the second cooler (132) fails, the reliquefaction efficiency is the same as when the first compressor (120) or the first cooler (130) fails. The third valve (193) and the fourth valve (194) are closed, and only the evaporated gas that has passed through the first compressor (120) and the first cooler (130) is discarded. Operate the system.

  On the other hand, when the ship operates at such a high speed that most or all of the evaporated gas discharged from the storage tank (T) can be used as fuel for the fuel demand destination (180), the evaporated gas to be reliquefied. The amount of will be very small. Therefore, when the ship operates at a high speed, only the first compressor (120) or the second compressor (122) can be driven.

  The first compressor (120) and the second compressor (122) can compress the evaporative gas to a pressure required from the fuel demand destination (180), and the fuel demand destination (180) is driven using the evaporative gas as fuel. Engine, generator, etc. As an example, when the fuel demand destination (180) is a marine vessel propulsion engine, the first compressor (120) and the second compressor (122) can compress the evaporated gas at a pressure of about 10 to 100 bar.

  The first compressor (120) and the second compressor (122) can compress the evaporated gas at a pressure of about 150 bar to 400 bar when the fuel demand destination (180) is a ME-GI engine. If the fuel consumer (180) is DFDE, the evaporative gas can be compressed at a pressure of about 6.5 bar, and if the fuel consumer (180) is an X-DF engine, the evaporative gas can be compressed at a pressure of about 16 bar. Can be compressed.

  The fuel demand destination (180) includes various types of engines. For example, when the fuel demand destination (180) includes an X-DF engine and a DFDE, the first compressor (120) and the second compressor (122) compresses the evaporated gas to the pressure required by the X-DF engine, and installs a decompression device upstream of the DFDE so that the compressed vapor gas is compressed to the pressure required by the X-DF engine. A portion can also be supplied to the DFDE down to the pressure required by the DFDE.

  In addition, in order to increase the reliquefaction efficiency and reliquefaction amount in the first heat exchanger (110) and the second heat exchanger (140), the first compressor (120) or the second compressor (122) may be used. The evaporative gas is compressed so that the pressure of the evaporative gas exceeds the pressure required by the fuel customer (180), and a decompression device is installed upstream of the fuel customer (180). After the pressure of the evaporated gas compressed so as to exceed the pressure required by the fuel is reduced to a pressure required by the fuel customer (180), it can be supplied to the fuel customer (180).

  Meanwhile, the first compressor (120) and the second compressor (122) may each be a multistage compressor. FIG. 4 shows that one compressor (120 or 122) compresses the evaporative gas to the pressure required by the fuel customer (180), but the first compressor (120) and the second compression are shown. If the machine (122) is a multi-stage compressor, the evaporative gas can be compressed multiple times by a plurality of compression cylinders to the pressure required by the fuel customer (180).

  When the first compressor (120) and the second compressor (122) are multistage compressors, a plurality of compression cylinders are connected in series inside the first compressor (120) and the second compressor (122). A plurality of coolers may be installed downstream of the plurality of compression cylinders.

  The 1st cooler (130) of a present Example is installed in the downstream of the 1st compressor (120), and cools the evaporative gas which not only the pressure but the temperature rose by being compressed by the 1st compressor (120). To do. The 2nd cooler (132) of a present Example is installed in the downstream of the 2nd compressor (122), and cools the evaporative gas which not only the pressure but also the temperature rose by the 2nd compressor (122). To do. The first cooler (130) and the second cooler (132) can cool the evaporative gas by exchanging heat with seawater, fresh water or air flowing in from the outside.

  The second heat exchanger (140) of this embodiment is cooled by the first heat exchanger (110) and then supplied to the second heat exchanger (140) along the return line (L3). The refrigerant decompression device (160) of this 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.

  That is, the second heat exchanger (140) depressurizes the evaporative gas that passes through the first heat exchanger (110) and is supplied to the second heat exchanger (140) along the return line (L3). The evaporative gas expanded by the device (160) is heat-exchanged as a refrigerant and further cooled.

  The refrigerant decompression device (160) of the present embodiment can be various means for lowering the pressure of the fluid, and the state of the fluid immediately before passing through the refrigerant decompression device (160) and the state of the fluid immediately after passing through the refrigerant decompression device (160). May vary depending on the operating conditions of the system. However, when the refrigerant decompression device (160) is an expander, in order to prevent physical damage to the refrigerant decompression device (160), the fluid immediately before passing through the refrigerant decompression device (160) and the fluid just after passing through the refrigerant decompression device (160). Is preferably maintained in a gaseous state. The same applies hereinafter.

  The evaporative gas that has passed through the refrigerant pressure reducing device (160) and is used as the heat exchange refrigerant in the second heat exchanger (140) is the evaporative gas compressed by the first compressor (120). ), And a part of the merged evaporative gas is supplied to the second heat exchanger (140) along the recirculation line (L5), and the second heat exchanger (140). Then, the evaporative gas that has passed through the refrigerant decompression device (160) is heat-exchanged as a refrigerant, cooled, and then supplied to the refrigerant decompression device (160).

  The evaporative gas supplied from the first supply line (L1) to the second heat exchanger (140) along the recirculation line (L5) is primarily cooled from the second heat exchanger (140). After being further cooled by the refrigerant pressure reducing device (160), it is sent again to the second heat exchanger (140) and used as a refrigerant.

  That is, the evaporative gas compressed by the first compressor (120) merges with the evaporative gas compressed by the second compressor (122) and passes to the second heat exchanger (140) along the recirculation line (L5). And the evaporative gas supplied to the second heat exchanger (140) along the return line (L3) through the first heat exchanger (110); and the refrigerant decompression device (160) The evaporative gas that has passed through is used as a refrigerant to be heat-exchanged and cooled.

  The first pressure reducing device (150) of the present embodiment is installed on the return line (L3), and expands the evaporated gas cooled by the first heat exchanger (110) and the second heat exchanger (140). . The evaporative gas compressed by the first compressor (120) merges with the evaporative gas compressed by the second compressor (122), and then partially branches to perform the first heat exchange along the return line (L3). It passes through the vessel (110), the second heat exchanger (140) and the first pressure reducing device (150), and a part or all of it is reliquefied.

  The first decompressor (150) comprises all means capable of expanding and cooling the evaporating gas and can be an expansion valve or expander, such as a Joule-Thomson valve.

  The ship in the present embodiment is installed on the return line (L3) downstream of the first decompression device (150), and separates the gas-liquid mixture discharged from the first decompression device (150) into a gas component and a liquid component. A gas-liquid separator (170) can be provided.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the liquid or gas-liquid mixed vapor that has passed through the first pressure reducing device (150) is immediately sent to the storage tank (T).

  When the ship in the present embodiment includes a gas-liquid separator (170), the evaporated gas that has passed through the first pressure reducing device (150) is sent to the gas-liquid separator (170) and separated into a gas component and a liquid component. . The liquid component separated by the gas-liquid separator (170) returns to the storage tank (T) along the return line (L3), and the gas component separated by the gas-liquid separator (170) is gas-liquid separated. It is supplied to the first heat exchanger (110) along the gas discharge line (L4) extending from the vessel (170) to the first supply line (L1) upstream of the first heat exchanger (110).

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

  The first to eighth valves and the eleventh valve of this embodiment (191, 192, 193, 194, 195, 196, 197, 198, 203) are manually operated by directly judging the operation status of the system. It can be adjusted automatically so that it is opened and closed according to a preset value.

  In order to easily explain the operation of the evaporative gas reliquefaction apparatus according to one embodiment of the present invention, the main flow of the evaporative gas is defined. A flow in which evaporative gas generated in the storage tank (T) and gas discharged from the gas-liquid separator (170) are supplied to the first heat exchanger (110) is a first flow (100), and the first heat exchanger. (110) to the first compressor (120) or the second compressor (122) and then discharged from the first compressor (120) or the second compressor (122) to the fuel demand destination (180). The supplied flow is branched from the second flow (102), downstream of the first compressor (120) and the second compressor (122) from the second flow (102), and supplied to the second heat exchanger (140). The third flow (104) is branched from the second flow (102) downstream of the first compressor (120) and the second compressor (122) and supplied to the first heat exchanger (110). The fourth flow (106) from the first heat exchanger (110) to the second heat exchanger (14 The stream fed to) is defined as a fifth stream (108). The first flow (100) passes through the first heat exchanger (110) and becomes the second flow (102), and the fourth flow (106) passes through the first heat exchanger (110) and the fifth flow. (108)

  Hereinafter, with reference to FIG. 4, an operation of the apparatus for evaporating gas reliquefaction according to an embodiment of the present invention will be described.

  The vaporized gas generated in the storage tank (T) for storing the liquid liquefied gas is supplied to the first heat exchanger (110). At this time, the gaseous evaporative gas generated in the storage tank (T) merges with the gaseous evaporative gas discharged from the gas-liquid separator (170) after a certain period of time has elapsed after the operation of the system. A first flow (100) is formed. The evaporative gas finally supplied to the first heat exchanger (110) is the first flow (100).

  A 1st heat exchanger (110) collect | recovers the cold heat which the 1st flow (100) has, and plays the role which cools another evaporative gas. That is, the first heat exchanger (110) collects the cold heat of the first flow (100) and is re-supplied to the first heat exchanger (110) in the second flow (102). That is, the recovered cold is provided to the fourth stream (106).

  Accordingly, in the first heat exchanger (110), heat exchange is performed between the first flow (100) and the fourth flow (106), the first flow (100) is heated, and the fourth flow (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 then supplied to the first compressor (120) or the second compressor (122). It is compressed by the compressor (122).

  The second flow (102) in which the evaporating gas compressed by the first compressor (120) and the evaporating gas compressed by the second compressor (122) merge is partly second as the third flow (104). The refrigerant is supplied to the heat exchanger (140) as a refrigerant, and the other part is supplied to the first heat exchanger (110) as a fourth flow (106) to be cooled, and the remaining part is supplied to the fuel demand destination. (180).

  The third flow (104) supplied to the second heat exchanger (140) is discharged from the second heat exchanger (140) and expanded by the refrigerant decompression device (160), and then the second heat exchanger again. (140). At this time, the third flow (104) primarily supplied to the second heat exchanger (140) is expanded by the refrigerant decompression device (160) and then supplied again to the second heat exchanger (140). Heat exchange with the third stream (104) to be cooled. The third flow (104) that has passed through the refrigerant decompression device (160) and the second heat exchanger (140) merges with the second flow (102) discharged from the first heat exchanger (110), and It is supplied to the first compressor (120) or the second compressor (122).

  The fourth flow (106) cooled by exchanging heat with the first flow (100) in the first heat exchanger (110) is supplied to the second heat exchanger (140) as a fifth flow (108). Is done. The fifth flow (108) supplied to the second heat exchanger (140) is cooled by heat exchange with the third flow (104) that has passed through the refrigerant pressure reduction device (160), and then the first pressure reduction device ( 150). The 5th flow (108) which passed the 1st pressure reduction device (150) will be in the gas-liquid mixture state with which gas and the liquid were mixed.

  The fifth stream (108) in the gas-liquid mixture state is immediately sent to the storage tank (T) or separated into a gas component and a liquid component while passing through the gas-liquid separator (170). The liquid component separated by the gas-liquid separator (170) is supplied to the storage tank (T), and the gas component separated by the gas-liquid separator (170) is supplied again to the first heat exchanger (110). The above process is repeated.

  FIG. 5 is a block diagram schematically showing an evaporative gas treatment system for a ship according to a fourth embodiment of the present invention.

  Compared to the ship in the third embodiment shown in FIG. 4, the ship in the fourth embodiment shown in FIG. 5 has an additional compressor (124) and additional cooling installed in the second supply line (L2). A ninth valve (201), a tenth valve (202), a tenth valve (202), a propulsion compressor (126) installed in the return line (L3), and a propulsion cooler (136). 12 valves (205) and a first additional line (L6) are further provided, and a part of the line through which the evaporative gas flows is changed so that the refrigerant cycle can be operated in a closed loop or an open loop. There is a difference in the above, and the following description will focus on the difference. Detailed description of the same members as those of the ship in the third embodiment described above will be omitted.

  Referring to FIG. 5, the ship in the present embodiment is similar to the third embodiment in that the first heat exchanger (110), the first valve (191), the first compressor (120), the first cooler ( 130), second valve (192), third valve (193), second compressor (122), second cooler (132), fourth valve (194), second heat exchanger (140), refrigerant A pressure reducing device (160) and a first pressure reducing device (150) are provided.

  As in the third embodiment, the storage tank (T) of this embodiment stores liquefied gas such as liquefied natural gas and liquefied ethane gas inside, and discharges evaporative gas to the outside when the internal pressure exceeds a predetermined level. . The evaporative gas discharged from the storage tank (T) is sent to the first heat exchanger (110).

  As in the third embodiment, the first heat exchanger (110) of the present embodiment uses the evaporative gas discharged from the storage tank (T) as a refrigerant and uses the first heat exchanger (110) along the return line (L3). The evaporated gas sent by the heat exchanger (110) is cooled. That is, the first heat exchanger (110) collects the cold heat of the evaporated gas discharged from the storage tank (T), and the collected cold heat is returned to the first heat exchanger (110) along the return line (L3). The evaporative gas sent to is supplied. A fifth valve (195) for adjusting the flow rate and opening / closing of the evaporating gas may be installed on the return line (L3).

  As in the third embodiment, the first compressor (120) of the present embodiment is installed on the first supply line (L1) and compresses the evaporated gas discharged from the storage tank (T). The second compressor (122) of the example was installed in parallel with the first compressor (120) on the second supply line (L2) and discharged from the storage tank (T) as in the third embodiment. Compress the evaporative gas. The first compressor (120) and the second compressor (122) can be compressors of the same performance, or each can be a multi-stage compressor.

  The 1st compressor (120) and the 2nd compressor (122) of a present Example can compress evaporative gas to the pressure requested | required from a fuel consumer (180) similarly to a 3rd Example. Further, when the fuel demander (180) has a plurality of types of engines, the fuel gas is compressed in accordance with the required pressure of an engine that requires higher pressure (hereinafter referred to as “high pressure engine”). Later, a part is supplied to the high-pressure engine, and the other part is decompressed by a decompression device installed upstream of the engine that requires lower pressure (hereinafter referred to as “low-pressure engine”). Can be supplied. In addition, in order to increase the reliquefaction efficiency and the reliquefaction amount in the first heat exchanger (110) and the second heat exchanger (140), the evaporative gas is supplied to the first compressor (120) or the second compressor ( 122) is compressed at a pressure higher than the pressure required by the fuel consumer (180), and a decompression device is installed upstream of the fuel consumer (180), and the pressure of the evaporated gas compressed at the high pressure is used as the fuel demand. It can also be supplied to the fuel demand destination (180) after the pressure to the pressure required by the tip (180) is reduced.

  As in the third embodiment, the ship in this embodiment is installed upstream of the fuel demand destination (180), and an eleventh valve for adjusting the flow rate and opening / closing of the evaporative gas sent to the fuel demand destination (180) ( 203).

  Since the ship in the present embodiment uses the evaporative gas compressed by the second compressor (122) as a refrigerant for further cooling the evaporative gas in the second heat exchanger (140), as in the third embodiment. Reliquefaction efficiency and reliquefaction amount can be increased.

  The 1st cooler (130) of a present Example is installed in the downstream of the 1st compressor (120) similarly to 3rd Example, and not only passes through a 1st compressor (120) but a pressure. The evaporated gas whose temperature has risen is cooled. Similar to the third embodiment, the second cooler (132) of the present embodiment is installed downstream of the second compressor (122) and passes through the second compressor (122) to not only the pressure but also the temperature. Cool the raised evaporative gas.

  Similarly to the third embodiment, the second heat exchanger (140) of the present embodiment is supplied to the first heat exchanger (110) along the return line (L3), and the first heat exchanger (110) is supplied. The evaporative gas cooled by the above is further cooled.

  According to the present embodiment, as in the third embodiment, the evaporated gas discharged from the storage tank (T) is further cooled not only by the first heat exchanger (110) but also by the second heat exchanger (140). Thus, since it can be supplied to the first pressure reducing device (150) at a lower temperature, the reliquefaction efficiency and the reliquefaction amount are increased.

  Similarly to the third embodiment, the refrigerant decompression device (160) of the present embodiment expands the evaporated gas that has passed through the second heat exchanger (140), and then sends it again to the second heat exchanger (140). .

  The first decompression device (150) of the present embodiment is installed on the return line (L3) as in the third embodiment, and is formed by the first heat exchanger (110) and the second heat exchanger (140). The cooled evaporative gas is expanded. The first decompression device (150) of the present embodiment includes all means capable of expanding and cooling the evaporative gas, and may be an expansion valve or an expander such as a Joule-Thomson valve.

  As in the third embodiment, the ship in this embodiment is installed on the return line (L3) downstream of the first decompression device (150), and the gas-liquid mixture discharged from the first decompression device (150) is removed. A gas-liquid separator (170) for separating the gas component and the liquid component can be provided.

  As in the third embodiment, when the ship in this embodiment does not include the gas-liquid separator (170), the evaporated gas in the liquid state or gas-liquid mixed state that has passed through the first pressure reducing device (150) is immediately When the ship in the present embodiment is provided with the gas-liquid separator (170), the evaporated gas that has passed through the first decompression device (150) is sent to the gas-liquid separator (170). Sent and separated into gaseous and liquid components. The liquid component separated by the gas-liquid separator (170) returns to the storage tank (T) along the return line (L3), and the gas component separated by the gas-liquid separator (170) is returned to the gas-liquid separator. It is supplied to the first heat exchanger (110) along the gas discharge line (L4) extending from (170) to the first supply line (L1) upstream of the first heat exchanger (110).

  When the ship in this embodiment includes a gas-liquid separator (170), the flow rate of the liquid separated by the gas-liquid separator (170) and sent to the storage tank (T) is adjusted as in the third embodiment. A seventh valve (197); and an eighth valve (198) for adjusting the flow rate of the gas separated by the gas-liquid separator (170) and sent to the first heat exchanger (110).

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

  Further, unlike the third embodiment in which the ship in this embodiment is selectively provided with a sixth valve, the evaporated gas branched from the first supply line (L1) is supplied to the second heat exchanger (140). A sixth valve (196) that is installed on the recirculation line (L5) to be sent and adjusts the flow rate and opening / closing of the evaporative gas is essential.

  The additional compressor (124) of the present embodiment is 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 produced by the refrigerant decompression device (160) while expanding the fluid, and the capacity of the additional compressor (124) is produced by the refrigerant decompression device (160). It can be a capacity driven by power. In the present embodiment, the case where the refrigerant decompression device (160) uses the power produced while expanding the fluid in the additional compressor (124) will be described as an example, but the refrigerant decompression device (160) produces the power. The system can also be configured to use power in the first compressor (120) and the second compressor (122).

  The types of compressors include a centrifugal compressor that rotates an impeller at high speed and compresses gas by energy generated by centrifugal force, and a reciprocating compressor that compresses gas by reciprocating movement of a piston in a cylinder (Reciprocating). There are screw compressors (Screw Compressors) that compress gas by the engagement of two rotors. Among them, reciprocating compressors and screw compressors are volumes that compress the gas sucked into a certain volume. It belongs to the type of compressor (Positive Displacement Compressor).

  The first compressor (120) and the second compressor (122) of this embodiment are preferably positive displacement compressors, and the additional compressor (124) is preferably a centrifugal compressor, but the additional compressor ( 124) is installed downstream of the second compressor (122), the second compressor (122) compresses the same flow rate as the first compressor (120) and therefore passes through the second supply line (L2). The mass flow rate of the evaporated gas is the same, and the effect of increasing only the pressure 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 high density becomes the second compressor (122). Therefore, the mass flow rate of the evaporative gas supplied to the second compressor (122) can be increased.

  That is, when the additional compressor (124) is installed upstream of the second compressor (122), the evaporated gas discharged from the storage tank (T) and supplied to the second supply line (L2) is additionally compressed. Since the density is increased by being compressed by the machine (124), the mass of the evaporated gas supplied to the second compressor (122) becomes larger even if the same flow rate of the evaporated gas is supplied to the second compressor (122). . Eventually, after being compressed by the second compressor (122), the mass of the fluid used as the refrigerant in the second heat exchanger (140) becomes larger, so the reliquefaction efficiency in the second heat exchanger (140) And the amount of reliquefaction can be increased. When the additional compressor (124) is installed upstream of the second compressor (122), it can be operated not only in the closed loop and the independent open loop of this embodiment, but also in the outlet pressure of the second compressor (122). Can be adjusted in the same manner as the outlet pressure of the first compressor (120) and operated in an open loop.

  Also, 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) It will only do the role of increasing pressure. Although this can also be expected to improve efficiency compared to the prior art, it is restrictive, so the additional compressor (124) is preferably installed upstream of the second compressor (122). When the additional compressor (124) is installed downstream of the second compressor (122), in this embodiment, it can be operated in a closed loop and an independent open loop, and the evaporation that has passed through the first supply line (L1). Open loop operation can be difficult because the gas and the pressure of the evaporating gas that has passed through the second supply line (L2) are different.

  In this embodiment, a similar effect can be achieved by increasing the pressure and capacity of the second compressor (122) instead of installing the additional compressor (124). However, if the second compressor (122) having a large pressure and capacity is used, the cost increases.

  According to the present embodiment, the power produced by the refrigerant pressure reducing device (160) can be used, and by adding the additional compressor (124), the reliquefaction efficiency and the reliquefaction amount can be increased at low cost. it can.

  The additional cooler (134) of the present embodiment lowers the temperature of the evaporated gas that has been compressed by the additional compressor (124) and whose temperature has risen as well. When the additional compressor (124) is installed upstream of the second compressor (122), the additional compressor (124), the additional cooler (134), the second compressor (122), and the second cooler When the additional compressor (124) is installed downstream of the second compressor (122), the second compressor (122), the second cooler (132), and the additional compressor (124) are installed. The compressor (124) and the additional cooler (134) are installed in this order.

  The propulsion compressor (126) of the present embodiment branches a part of the evaporated gas supplied to the fuel consumer (180) along the first supply line (L1) to the first heat exchanger (110). It is installed on the return line (L3) to be sent, and the pressure of the evaporative gas supplied to the first heat exchanger (110) along the return line (L3) is increased. The propulsion compressor (126) can compress the evaporated gas to a pressure below a critical point (about 55 bar in the case of methane) and to a pressure exceeding the critical point. If the machine (126) compresses the evaporative gas above the critical point, it can be compressed to about 300 bar.

  The propulsion cooler (136) of this example was installed on the return line (L3) downstream of the propulsion compressor (126), and not only the pressure but also the temperature rose through the propulsion compressor (126). Reduce the temperature of the evaporating gas.

  The ship in the present embodiment further includes a propulsion compressor (126), and can increase the pressure of the evaporative gas passing through the reliquefaction process, so that the reliquefaction amount and the reliquefaction efficiency can be increased.

  FIG. 9 is a graph showing methane temperature values according to heat flow rates under different pressures. Referring to FIG. 9, it can be confirmed that the higher the pressure of the evaporative gas that undergoes the reliquefaction process, the higher the efficiency of self-heat exchange. The self heat exchange means that the low-temperature evaporative gas itself is used as a cooling fluid to exchange heat with the high-temperature evaporative gas.

  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 provided, and FIG. 9 (b) shows the propulsion. When the compressor (126) and the propulsion cooler (136) are provided, the state of each fluid in the second heat exchanger (140) is shown.

  The uppermost graph I in FIGS. 9A and 9B shows the fluid state at the point A in FIG. 5 supplied to the second heat exchanger 140 along the recirculation line L5. Since the lowermost graph L passes through the second heat exchanger (140) and the refrigerant pressure reducing device (160) along the recirculation line (L5) and is used as a refrigerant, the second heat exchanger (140 FIG. 5 shows the fluid state at the point C in FIG. 5 again, and a graph J drawn overlapping the graph K in the middle portion passes through the first heat exchanger (110) and returns to the return line. It shows the fluid state at point E in FIG. 5 supplied by the second heat exchanger (140) along (L3).

  Since the fluid used as the refrigerant is deprived of cold heat in the process of heat exchange and gradually rises in temperature, the graph L moves from the left side to the right side as time passes, and is fluid that is cooled by heat exchange with the refrigerant. In the process of heat exchange, the temperature gradually decreases due to the cold heat from the refrigerant, so that the graph I and the graph J are moved from the right side to the left side as time passes.

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

  When designing a heat exchanger, the temperature and heat flow of the fluid supplied to the heat exchanger (ie, point A, point C, and point E in FIG. 5) are fixed, and the fluid used as the refrigerant is fixed. The logarithm mean temperature difference (LMTD; Logarithmic) while the temperature is not higher than the temperature of the fluid being cooled (ie, the graph L and the graph K intersect and the graph L is not displayed above the graph K). (Mean Temperature Difference) is set to a minimum value.

  The logarithmic mean temperature difference (LMTD) is the temperature before the cryogenic fluid passes through the heat exchanger in the case of counter flow, which is a heat exchange system in which hot fluid and cold fluid are injected in opposite directions and discharged from opposite sides. , Tc1, the temperature after the low temperature fluid passes through the heat exchanger, tc2, the temperature before the high temperature fluid passes through the heat exchanger, th1, the temperature after the high temperature fluid passes through the heat exchanger, th2, and d1 = Th2-tc1, d2 = th1-tc2, the value is expressed by (d2-d1) / ln (d2 / d1). The smaller the logarithm average temperature difference, the higher the efficiency of the heat exchanger.

  On the graph, the logarithmic mean temperature difference (LMTD) is expressed by the interval between a low-temperature fluid used as a refrigerant (graph L in FIG. 9) and a high-temperature fluid cooled by heat exchange with the refrigerant (graph K in FIG. 9). 9A, it can be seen that the interval between the graph L and the graph K is displayed narrower in FIG. 9B.

  This difference is supplied to the second heat exchanger (140) along the return line (L3) after passing through the first heat exchanger (110) through the initial value of the graph J, which is a point indicated by a round circle. This is because the fluid pressure at point E in FIG. 5 is higher in FIG. 9B than in FIG. 9A.

  That is, as a result of the simulation, in the case of FIG. 9A without the propulsion compressor (126), the fluid at the point E in FIG. 5 is about −111 ° C. and 20 bar, and the propulsion compressor (126). 9 (b), the fluid at point E in FIG. 5 is about −90 ° C. and 50 bar, but the logarithmic mean temperature difference (LMTD) is minimized under these initial conditions. If the heat exchanger is designed so that the efficiency of the heat exchanger becomes higher in the case of FIG. 9 (b) where the pressure of the evaporative gas passing through the reliquefaction process is high, and eventually the entire system is regenerated. The amount of liquefaction and reliquefaction efficiency will increase.

  In the case of FIG. 9 (a), if the flow rate of the evaporative gas used as the refrigerant in the second heat exchanger (140) is about 6401 kg / h, the refrigerant and heat are obtained from the fluid (graph L) used as the refrigerant. The total heat flow transferred to the exchanged and cooled fluid (graph K) is about 585.4 kW, and the re-liquefied evaporative gas flow is about 3441 kg / h.

  In the case of (b) of FIG. 9, if the flow rate of the evaporative gas used as the refrigerant in the second heat exchanger (140) is about 5368 kg / h, the refrigerant and the heat from the fluid (graph L) used as the refrigerant. The total heat flow transferred to the exchanged and cooled fluid (graph K) is about 545.2 kW, and the re-liquefied evaporative gas flow is about 4325 kg / h.

  That is, when the pressure of the evaporative gas that undergoes the reliquefaction process including the propulsion compressor (126) is increased, a larger amount of the evaporative gas can be reliquefied even if less refrigerant is used.

  Thus, since the ship in a present Example is equipped with a propulsion compressor (126), it can raise the amount of reliquefaction and reliquefaction efficiency, raise the amount of reliquefaction and reliquefaction efficiency, and can improve the amount of reliquefaction and reliquefaction efficiency (122). ) Increase the number of cases where all of the evaporated gas can be processed without driving, and the frequency of use of the second compressor (122) can be reduced.

  The re-liquefaction efficiency can be increased by using the second compressor (122), but the longer the time for driving the second compressor (122), the more prepared for a failure of the first compressor (120). The concept of redundancy is reduced. Since the ship in a present Example is equipped with a propulsion compressor (126) and can reduce the usage frequency of a 2nd compressor (122), the concept of redundancy can fully be ensured.

  Further, since the propulsion compressor (126) generally has a capacity of about ½ that of the first compressor (120) or the second compressor (122), the second compressor (122) is not driven. When the system is operated by driving only the propulsion compressor (126) and the first compressor (120), the operation cost can be reduced compared to the case where the propulsion compressor (126) is not installed.

  Referring further to FIG. 5, one end of the first additional line (L6) of the present embodiment is expanded by the refrigerant pressure reducing device (160) and the evaporated gas passing through the second heat exchanger (140) is supplied to the first supply line. The other end is connected to the second supply line (L2) between the third valve (193) and the second compressor (122). The

  The ninth valve (201) of the present embodiment is configured such that the recirculation line (L5) is in contact with the first supply line (L1) upstream of the first compressor (120) and the second compressor (122), and the recirculation line (L5). The circulation line (L5) is installed on the recirculation line (L5) between the point where it contacts the first additional line (L6). Further, the ship in the present embodiment is different from the third embodiment in that the second supply line (L2) on the downstream side of the second compressor (122) is not the first supply line (L1) but the recirculation line ( L5).

  The twelfth valve (205) of the present embodiment is installed on the recirculation line (L5) between the second supply line (L2) and the second heat exchanger (140) to control the flow rate and opening / closing of the fluid. Adjust.

  The first to twelfth valves (191, 192, 193, 194, 195, 196, 197, 198, 201, 202, 203, 205) of this embodiment are manually operated by directly judging the system operation status. It can be adjusted and automatically adjusted to be opened and closed by a preset value.

  The feature of the present embodiment that differs from the third embodiment of the ship is that the refrigerant cycle can be operated not only in the open loop but also in the closed loop, and the reliquefaction system can be used more flexibly according to the operating conditions of the ship. Hereinafter, when the additional compressor (124) is installed upstream of the second compressor (122), a method of operating the refrigerant cycle in a closed loop and a method of operating in an open loop through valve adjustment Will be explained.

  In order to operate the refrigerant cycle of the ship in this embodiment in a closed loop, first, the first valve (191), the second valve (192), the third valve (193), the fourth valve (194), the tenth valve ( 202), the twelfth valve (205) is opened, and the sixth valve (196) and the ninth valve (201) are closed to drive the system.

  When the evaporated gas discharged from the storage tank (T) and compressed by the second compressor (122) is supplied to the recirculation line (L5), the third valve (193) is closed and the evaporated gas is added to the additional compressor. (124), additional cooler (134), second compressor (122), second cooler (132), fourth valve (194), twelfth valve (205), second heat exchanger (140), A closed-loop refrigerant cycle that circulates through the refrigerant decompression device (160), the second heat exchanger (140), and the tenth valve (202) is formed again.

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

  When the refrigerant cycle is operated in a closed loop, only the evaporative gas circulating in the closed loop is used as the refrigerant in the second heat exchanger (140), and the evaporative gas that has passed through the first compressor (120) is introduced into the refrigerant cycle. Instead, it is supplied to the fuel customer (180) or undergoes a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction and the amount of evaporated gas required from the fuel demand destination (180), the evaporated gas having a constant flow rate is circulated as the refrigerant of the second heat exchanger (140).

  When the refrigerant cycle of this embodiment is operated in a closed loop, the flow rates of the evaporative gas used as a refrigerant and the evaporative gas used as the refrigerant are controlled compared to the case where the refrigerant cycle is operated in an open loop or an independent open loop. There is an advantage that it is easy to do.

In the present embodiment, only one compressor (120) is installed in the first supply line (L1), and two compressors (122, 124) are installed in the second supply line (L2). Therefore, the pressure of the evaporating gas that has passed through the first supply line (L1) may be different from the pressure of the evaporating gas that has passed through the second supply line (L2). When the evaporative gas passing through the first supply line (L1) and the evaporative gas passing through the second supply line (L2) have different pressures, the refrigerant cycle of this embodiment is operated in a closed loop or an independent open loop. Is preferred.

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

  The evaporative gas discharged from the storage tank (T) passes through the first heat exchanger (110), is compressed by the first compressor (120), and is cooled by the first cooler (130). A part is sent to the fuel demand destination (180), and the remaining part goes through a reliquefaction process along the return line (L3).

  The evaporative gas that has undergone the reliquefaction process along the return line (L3) is compressed by the propulsion compressor (126) and cooled by the propulsion cooler (136), and then stored in the storage tank (110) by the first heat exchanger (110). Heat is exchanged with the evaporative gas discharged from T) and cooled. The evaporative gas cooled by the first heat exchanger (110) is heat-exchanged by the second heat exchanger (140), further cooled, and then expanded by the first decompression device (150) to be partially or completely. Is reliquefied.

  In this embodiment, the evaporative gas that has undergone the reliquefaction process along the return line (L3) is compressed by the propulsion compressor (126), and then the first heat exchanger (110) and the second heat exchanger (140). ), The evaporative gas compressed by the propulsion compressor (126) is immediately sent to the second heat exchanger (140) to be cooled, and then the first decompressor. (150) can be expanded and reliquefied. The same applies when the refrigerant cycle of this embodiment is operated in an open loop and an independent open loop.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the partially or wholly reliquefied evaporative gas is immediately sent to the storage tank (T), and the ship in the present embodiment performs the gas-liquid separation. When the vessel (170) is provided, the partially or wholly reliquefied evaporated gas is sent to the gas-liquid separator (170). The gas separated by the gas-liquid separator (170) merges with the evaporating gas discharged from the storage tank (T), is sent to the first heat exchanger (110), and is separated by the gas-liquid separator (170). The liquid is sent to the storage tank (T).

  On the other hand, the evaporative gas circulating in the refrigerant cycle is compressed by the additional compressor (124) and cooled by the additional cooler (134), and further compressed by the second compressor (122) to be compressed by the second cooler (122). 132) and sent to the second heat exchanger (140) along the recirculation line (L5). The evaporative gas passing through the additional compressor (124) and the second compressor (122) and sent to the second heat exchanger (140) is primarily heat-exchanged from the second heat exchanger (140). Then, the refrigerant is sent to the refrigerant pressure reducing device (160) and secondarily expanded and cooled.

  In this embodiment, the evaporative gas used as the refrigerant along the recirculation line (L5) first passes through the second heat exchanger (140), and then passes through the refrigerant decompression device (160), Although the case where the refrigerant is sent again to the second heat exchanger (140) has been described, the evaporative gas used as the refrigerant along the recirculation line (L5) is not directly passed through the second heat exchanger (140). After being sent to the decompression device (160), it can be sent to the second heat exchanger (140). The same applies when the refrigerant cycle of this embodiment is operated in an open loop and an independent open loop.

  The evaporated gas that has passed through the refrigerant pressure reducing device (160) is sent again to the second heat exchanger (140), passes through the first heat exchanger (110), and then passes through the return line (L3) to generate the second heat. Evaporated gas supplied to the exchanger (140); and compressed by the additional compressor (124) and the second compressor (122) and supplied to the second heat exchanger (140) along the recirculation line (L5). It is used as a refrigerant for cooling the evaporated gas. After passing through the refrigerant pressure reducing device (160), the evaporated gas used as the refrigerant in the second heat exchanger (140) is sent again to the additional compressor (124), and the above-described series of processes is repeated.

  If the first compressor (120) or the first cooler (130) breaks down while the refrigerant cycle of the ship in this embodiment is operated in a closed loop, the first valve (191), the second valve (192), The tenth valve (202) and the twelfth valve (205) are closed, the third valve (193) and the sixth valve (196) are opened, and the first heat exchanger (110) is discharged from the storage tank (T). The evaporated gas that has passed through the third valve (193), the additional compressor (124), the additional cooler (134), the second compressor (122), the second cooler (132), and the fourth valve (194) And it comprises so that it may be supplied to a fuel consumer (180) through a 6th valve (196). 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 second It is also possible to operate the system with 12 valves (205) open.

  In order to operate the ship refrigerant cycle in this embodiment in an open loop, the first valve (191), the second valve (192), the third valve (193), the fourth valve (194), the sixth valve (196) ), The ninth valve (201) and the twelfth valve (205) are opened, and the tenth valve (202) is closed.

  When the refrigerant cycle is operated in a closed loop, the evaporative gas circulating in the refrigerant cycle is separated from the evaporative gas that is sent to the fuel demand destination (180) or undergoes a reliquefaction process along the return line (L3). On the other hand, when the refrigerant cycle is operated in an open loop, the evaporative gas compressed by the first compressor (120) and the evaporative gas compressed by the second compressor (122) merge, and the second heat exchanger (140 ) As a refrigerant, sent to a fuel demand destination (180), or undergoes a reliquefaction process along the return line (L3).

  Therefore, when the refrigerant cycle is operated in an open loop, the flow rate of the refrigerant sent to the second heat exchanger (140) is fluidly adjusted in consideration of the reliquefaction amount and the evaporative gas requirements at the fuel demand destination (180). be able to. In particular, when the demand for evaporative gas from the fuel customer (180) is small, the reliquefaction efficiency and the reliquefaction amount can be increased by increasing the flow rate of the refrigerant sent to the second heat exchanger (140).

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

  The evaporative gas discharged from the storage tank (T) passes through the first heat exchanger (110) and then branches into two flows. A part of the evaporated gas is sent to the first supply line (L1), and the rest A part is sent to the second supply line (L2).

  The evaporative 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), The part passes through the sixth valve (196) and the twelfth valve (205) and is sent to the second heat exchanger (140), and the other part again branches into two flows. One of the evaporative gases branched into two flows is sent to the fuel demand destination (180), and the other is sent along the return line (L3) to the propulsion compressor (126).

  The evaporative gas sent to the second supply line (L2) is supplied from the third valve (193), the additional compressor (124), the additional cooler (134), the second compressor (122), and the second cooler (132). ) And the fourth valve (194), a part passes through the twelfth valve (205) and is sent to the second heat exchanger (140), and the other part passes through the first supply line (L1). Branch to two streams. One of the evaporative gases branched into two flows is sent to the fuel demand destination (180), and the other flow is sent to the propulsion compressor (126) along the return line (L3).

  For convenience of explanation, the evaporative gas compressed by the first compressor (120) and the evaporative gas compressed by the additional compressor (124) and the second compressor (122) have been described separately. However, the first compressor The evaporative gas compressed by (120) and the evaporative gas compressed by the additional compressor (124) and the second compressor (122) do not flow separately but join together to form the second heat exchanger ( 140), the fuel demand destination (180) or the propulsion compressor (126).

  That is, to the recirculation line (L5) for sending evaporative gas to the second heat exchanger (140), the first supply line (L1) for sending evaporative gas to the fuel demand destination (180), and the first heat exchanger (110). In the return line (L3) for sending the evaporation gas, the evaporation gas compressed by the first compressor (120) and the evaporation gas compressed by the additional compressor (124) and the second compressor (122) are mixed. Flowing.

  The evaporative gas sent to the second heat exchanger (140) along the recirculation line (L5) is primarily heat-exchanged and cooled by the second heat exchanger (140), and the refrigerant decompression device (160 ) Is secondarily expanded and cooled, and then supplied again to the second heat exchanger (140). The evaporative gas supplied to the second heat exchanger (140) through the refrigerant decompression device (160) passes through the first heat exchanger (110) and passes along the return line (L3) to the second heat exchanger. The evaporative gas supplied to (140); and the evaporative gas supplied to the second heat exchanger (140) along the recirculation line (L5) and compressed by the first compressor (120) and the additional compressor ( 124) and the flow of evaporative gas compressed by the second compressor (122) joined together;

  After passing through the refrigerant pressure reducing device (160), the evaporative gas used as the refrigerant in the second heat exchanger (140) passes through the ninth valve (201) and is sent to the first supply line (L1). The evaporative gas discharged from the storage tank (T) and passed through the first heat exchanger (110) joins, and the above-described series of processes is repeated.

  On the other hand, 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 the first heat exchange. To the vessel (110). The evaporative gas sent to the first heat exchanger (110) is primarily cooled by the first heat exchanger (110) and secondarily cooled by the second heat exchanger (140), and then the first pressure reducing device. (150) is expanded and part or all is reliquefied.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the partially or wholly reliquefied evaporative gas is immediately sent to the storage tank (T), and the ship in the present embodiment performs the gas-liquid separation. When the vessel (170) is provided, the partially or wholly reliquefied evaporative gas is sent to the gas-liquid separator (170). The gas separated by the gas-liquid separator (170) merges with the evaporating gas discharged from the storage tank (T) and is sent to the first heat exchanger (110), where it is sent by the gas-liquid separator (170). The separated liquid is sent to a storage tank (T).

  If the first compressor (120) or the first cooler (130) breaks down while the refrigerant cycle of the ship in this embodiment is operated in an open loop, the first valve (191) and the second valve (192) The 9th valve (201) and the 12th valve (205) are closed, and the evaporated gas discharged from the storage tank (T) and passed through the first heat exchanger (110) is added to the third valve (193). Fuel demand destination (180) via compressor (124), additional cooler (134), second compressor (122), second cooler (132), fourth valve (194) and sixth valve (196) It is configured to be supplied to. 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 second It is also possible to operate the system with 12 valves (205) open.

  The ship in the present embodiment uses the evaporative gas compressed by the second compressor (122) only with the refrigerant of the second heat exchanger (140) while operating the refrigerant cycle in an open loop. The evaporative gas compressed by the compressor (120) is sent to the fuel demand destination (180) or undergoes a reliquefaction process along the return line (L3), thereby serving as a refrigerant for the second heat exchanger (140). So that the second compressor (122) and the first compressor (120) can be operated independently. Hereinafter, an open-loop refrigerant cycle in which the second compressor (122) and the first compressor (120) are operated independently is referred to as an “independent open loop”.

  In order to operate the ship refrigerant cycle in this embodiment in an independent open loop, the first valve (191), the second valve (192), the third valve (193), the fourth valve (194), the ninth valve ( 201) and the twelfth valve (205) are opened, and the sixth valve (196) and the tenth valve (202) are closed. The advantage of operating the refrigerant cycle in an independent open loop is that it allows a relatively flexible system operation compared to a closed loop operation, but makes the system easier to operate than an open loop operation. There is.

  When the refrigerant cycle of the ship in this embodiment is operated in an independent open loop, the flow of the evaporative gas will be described as follows.

  The evaporative gas discharged from the storage tank (T) passes through the first heat exchanger (110), and then branches into two flows. A part is sent to the first supply line (L1), and the remaining one The part is sent to the second supply line (L2). The evaporative 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), The part is sent to the fuel demand destination (180), and the other part is sent to the propulsion compressor (126) along the return line (L3).

  The evaporative gas sent to the second supply line (L2) is supplied from the third valve (193), the additional compressor (124), the additional cooler (134), the second compressor (122), and the second cooler (132). ), After passing through the fourth valve (194) and the twelfth valve (205), it is sent to the second heat exchanger (140) along the recirculation line (L5).

  The evaporative gas compressed by the additional compressor (124) and the second compressor (122) and sent along the recirculation line (L5) to the second heat exchanger (140) is converted into the second heat exchanger (140). ) Is firstly heat-exchanged and cooled, secondarily expanded and cooled by the refrigerant decompression device (160), and then supplied again to the second heat exchanger (140). Evaporative gas passed through (110) and supplied to the second heat exchanger (140) along the return line (L3); and the recirculation line compressed by the additional compressor (124) and the second compressor (122) It is used as a refrigerant for cooling the evaporative gas supplied to the second heat exchanger (140) along (L5).

  After passing through the refrigerant pressure reducing device (160), the evaporative gas used as the refrigerant in the second heat exchanger (140) passes through the ninth valve (201) and is sent to the first supply line (L1). After being discharged from the storage tank (T), it merges with the evaporated gas that has passed through the first heat exchanger (110), and the above-described series of processes is repeated.

  After being compressed by the first compressor (120), the evaporative gas sent to the propulsion compressor (126) along the return line (L3) is compressed by the propulsion compressor (124), and the propulsion cooler (134). ) And then sent to the first heat exchanger (110). The evaporative gas sent to the first heat exchanger (110) is primarily cooled by the first heat exchanger (110) and secondarily cooled by the second heat exchanger (140), and then the first decompressor. (150) is expanded and part or all is reliquefied.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the partially or wholly reliquefied evaporative gas is immediately sent to the storage tank (T), and the ship in the present embodiment performs the gas-liquid separation. When the vessel (170) is provided, the partially or wholly reliquefied evaporated gas is sent to the gas-liquid separator (170). The gas separated by the gas-liquid separator (170) merges with the evaporated gas discharged from the storage tank (T) and is sent to the first heat exchanger (110), where it is separated by the gas-liquid separator (170). The liquid is sent to the storage tank (T).

  If the first compressor (120) or the first cooler (130) breaks down while the refrigerant cycle of the ship in this embodiment is operated in an independent open loop, the first valve (191) and the second valve (192) ), The ninth valve (201) and the twelfth valve (205) are closed, the sixth valve (196) is opened, and the vapor discharged from the storage tank (T) and passed through the first heat exchanger (110). Gases include a third valve (193), an additional compressor (124), an additional cooler (134), a second compressor (122), a second cooler (132), a fourth valve (194) and a sixth valve. (196) is configured to be supplied to the fuel customer (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 second It is also possible to operate the system with 12 valves (205) open.

  FIG. 6 is a configuration diagram schematically showing an evaporative gas treatment system for a ship according to a fifth embodiment of the present invention.

  The ship in the fifth embodiment shown in FIG. 6 does not include the first additional line (L6) as compared with the ship in the fourth embodiment shown in FIG. There is a difference in that the vessel (134) is installed in the recirculation line (L5), and the connection position of each line is changed little by little, and the difference will be mainly described below. Detailed description of the same members as those of the ship in the fourth embodiment described above will be omitted.

  Referring to FIG. 6, the ship in the present embodiment is similar to the fourth embodiment in that the first heat exchanger (110), the first valve (191), the first compressor (120), and the first cooler. (130), second valve (192), third valve (193), second compressor (122), second cooler (132), fourth valve (194), propulsion compressor (126), propulsion cooling (136), second heat exchanger (140), refrigerant decompression device (160), additional compressor (124), additional cooler (134), ninth valve (201), twelfth valve (205) and One decompression device (150) is provided.

  As in the fourth embodiment, the first heat exchanger (110) of the present embodiment uses the evaporated gas discharged from the storage tank (T) as a refrigerant, and performs the first heat along the return line (L3). The evaporated gas sent to the exchanger (110) is cooled. That is, the first heat exchanger (110) collects the cold heat of the evaporated gas discharged from the storage tank (T), and the collected cold heat is returned to the first heat exchanger (110) along the return line (L3). Supply to the sent evaporative gas. A fifth valve (195) for adjusting the flow rate and opening / closing of the evaporating gas may be installed on the return line (L3).

  As in the fourth embodiment, the first compressor (120) of the present embodiment is installed on the first supply line (L1) and compresses the evaporated gas discharged from the storage tank (T). The second compressor (122) of the example was installed in parallel with the first compressor (120) on the second supply line (L2) and discharged from the storage tank (T) as in the fourth embodiment. Compress the evaporative gas. The first compressor (120) and the second compressor (122) may be compressors having the same performance, and may be multistage compressors.

  The 1st compressor (120) and the 2nd compressor (122) of a present Example can compress evaporative gas to the pressure which a fuel consumer (180) requires similarly to a 4th Example. In addition, when the fuel demand destination (180) includes a plurality of types of engines, after the evaporation gas is compressed in accordance with the required pressure of an engine that requires a higher pressure (hereinafter referred to as “high pressure engine”). , A part is supplied to a high-pressure engine, and the other part is decompressed by a decompression device installed upstream of an engine requiring lower pressure (hereinafter referred to as a “low-pressure engine”), and then supplied to the low-pressure engine. Can be supplied. In addition, in order to increase the reliquefaction efficiency and the reliquefaction amount in the first heat exchanger (110) and the second heat exchanger (140), the evaporative gas is supplied to the first compressor (120) or the second compressor ( 122) is compressed to a pressure higher than the pressure required by the fuel consumer (180), and a decompression device is installed upstream of the fuel consumer (180), and the pressure of the evaporated gas compressed at the high pressure is used as the fuel demand. The pressure can be supplied to the fuel demand destination (180) after the pressure from the tip (180) is reduced to the required pressure.

  As in the fourth embodiment, the ship in the present embodiment is installed upstream of the fuel demand destination (180), and an eleventh valve for adjusting the flow rate and opening / closing of the evaporative gas sent to the fuel demand destination (180) ( 203).

  Since the ship in the present 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. Reliquefaction efficiency and reliquefaction amount can be increased.

  The 1st cooler (130) of a present Example is installed in the downstream of the 1st compressor (120) similarly to 4th Example, and not only a pressure is passing through the 1st compressor (120). The evaporated gas whose temperature has risen is cooled. Similar to the fourth embodiment, the second cooler (132) of the present embodiment is installed downstream of the second compressor (122), and not only the pressure while passing through the second compressor (122). The evaporated gas whose temperature has risen is cooled.

  Similar to the fourth embodiment, the propulsion compressor (126) of the present embodiment branches a part of the evaporative gas supplied to the fuel demand destination (180) along the first supply line (L1). It installs on the return line (L3) sent to 1 heat exchanger (110), and raises the pressure of the evaporation gas supplied to the 1st heat exchanger (110) along the return line (L3). The propulsion compressor (126) may compress the vaporized gas to a pressure below a critical point (about 55 bar in the case of methane) or may be compressed to a pressure exceeding the critical point. If (126) compresses the evaporative gas to above the critical point, it can be compressed to about 300 bar.

  As in the fourth embodiment, the propulsion cooler (136) of the present embodiment is installed on the return line (L3) downstream of the propulsion compressor (126), passes through the propulsion compressor (126), and has a pressure. As well as lowering the temperature of the evaporating gas, the temperature also increased.

  Since the ship in the present embodiment further includes a propulsion compressor (126), similarly to the fourth embodiment, it is possible to increase the reliquefaction amount and the reliquefaction efficiency by increasing the pressure of the evaporative gas passing through the reliquefaction process. The frequency of use of the second compressor (122) can be reduced, the concept of redundancy can be sufficiently ensured, and the operating cost can be reduced compared with the case where no propulsion compressor (126) is installed. Can do.

  Similarly to the fourth embodiment, the second heat exchanger (140) of the present embodiment is supplied to the first heat exchanger (110) along the return line (L3), and the first heat exchanger (110) is supplied. The evaporative gas cooled by the above is further cooled.

  According to the present 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). Then, since the temperature can be supplied to the first pressure reducing device (150) at a lower temperature, the reliquefaction efficiency and the reliquefaction amount are increased.

  Similarly to the fourth embodiment, the refrigerant decompression device (160) of the present embodiment expands the evaporated gas that has passed through the second heat exchanger (140) and then sends it again to the second heat exchanger (140). .

  The additional compressor (124) of the present embodiment compresses the fluid that has passed through the refrigerant decompression device (160) and the second heat exchanger (140), and the refrigerant decompression device (160) produces power while expanding the fluid. Driven by. That is, the refrigerant decompression device (160) and the additional compressor (124) of the present embodiment can form a compander (Compander, 900). The additional compressor (124) may have a smaller capacity than the second compressor (122), and may have a capacity that can be driven by the power generated by the refrigerant decompression device (160).

  However, unlike the fourth embodiment, the additional compressor (124) of the present embodiment is not installed on the second supply line (L2) but is branched from the second supply line (L2) to reduce the refrigerant pressure. The fluid that has passed through the device (160) and the second heat exchanger (140) is installed on the recirculation line (L5) that is sent to the second supply line (L2) again.

  According to the present embodiment, similar to the fourth embodiment, the power produced by the refrigerant pressure reducing device (160) can be utilized, and the additional compressor (124) having a smaller capacity than the second compressor (122). By adding, the reliquefaction efficiency and reliquefaction amount can be increased at low cost.

  As in the fourth embodiment, the additional cooler (134) of the present embodiment is installed downstream of the additional compressor (124) and is compressed by the additional compressor (124) to increase not only the pressure but also the temperature. Reduce the temperature of the evaporated gas. However, unlike the fourth embodiment, the additional cooler (134) of the present embodiment is installed on the recirculation line (L5).

  In this embodiment, the additional compressor (124) and the additional cooler (134) are installed on the recirculation line (L5), and the fluid used as the refrigerant in the second heat exchanger (140) is the fourth. Even if the first compressor (120) or the first cooler (130) fails, the second compression is easier than in the fourth embodiment while being configured to circulate through the same path as the closed-loop refrigerant cycle of the embodiment. The evaporated gas that has passed through the machine (122) and the second cooler (132) can be supplied as fuel to the fuel demand destination (180).

  Hereinafter, the time when the first compressor (120) and the first cooler (130) operate normally is referred to as "normal time", and the first compressor (120) or the first cooler (130) has failed. The case is called “emergency”.

  That is, according to the present embodiment, the fluid used as the refrigerant in the second heat exchanger (140) flows along the recirculation 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) again. After passing, it is sent again to the additional compressor (124), and therefore circulates through the same refrigerant cycle as the closed-loop refrigerant cycle of the fourth embodiment.

  Further, according to the fourth embodiment, the evaporative gas supplied to the fuel demand destination (180) along the second supply line (L2) in an emergency is supplied to the additional compressor (124) and the second compressor (122). Therefore, when the second compressor (122) has the same performance as the first compressor (120), the second supply line (L2) is used in an emergency. The pressure of the evaporative gas supplied to the fuel demand destination (180) along the first supply line (L1) along the first supply line (L1) is normally higher than the pressure of the evaporative gas supplied to the fuel demand destination (180). it can.

  Therefore, according to the fourth embodiment, the pressure of the evaporative gas supplied to the fuel demand destination (180) along the second supply line (L2) in the event of an emergency is adjusted along the first supply line (L1) during normal times. In order to match the pressure of the evaporative gas supplied to the fuel demand destination (180), another control is required, and it may be difficult to use the second compressor (122) as redundancy. May occur.

  On the other hand, according to the present embodiment, the evaporative gas supplied to the fuel consumer (180) along the second supply line (L2) in an emergency is not compressed by the additional compressor (124), and the second compressor If the second compressor (122) has the same performance as the first compressor (120) because it is compressed only by (122) and supplied to the fuel demand destination (180), there is no additional pressure adjustment in an emergency. Evaporated gas can be easily supplied to the fuel demand destination (180) via the second supply line (L2).

  The first decompression device (150) of the present embodiment is installed on the return line (L3) as in the fourth embodiment, and is cooled by the first heat exchanger (110) and the second heat exchanger (140). The evaporated gas is expanded. The first decompression device (150) of this embodiment can be an expansion valve or expander, such as a Joule-Thomson valve, with all means capable of expanding and cooling the evaporative gas.

  As in the fourth embodiment, the ship in this embodiment is installed on the return line (L3) downstream of the first decompression device (150), and the gas-liquid mixture discharged from the first decompression device (150) is removed. A gas-liquid separator (170) for separating the gas component and the liquid component can be provided.

  Similarly to the fourth embodiment, when the ship in this embodiment does not include the gas-liquid separator (170), the evaporated gas in the liquid state or the gas-liquid mixed state that has passed through the first decompression device (150) is immediately When the ship in the present embodiment is provided with the gas-liquid separator (170), the evaporated gas that has passed through the first decompression device (150) is sent to the gas-liquid separator (170). Sent and separated into gaseous and liquid components. The liquid component separated by the gas-liquid separator (170) returns to the storage tank (T) along the return line (L3), and the gas component separated by the gas-liquid separator (170) is gas-liquid separated. It is supplied to the first heat exchanger (110) along the gas discharge line (L4) extending from the vessel (170) to the first supply line (L1) upstream of the first heat exchanger (110).

  When the ship in this embodiment includes a gas-liquid separator (170), the flow rate of the liquid separated by the gas-liquid separator (170) and sent to the storage tank (T) is adjusted, as in the fourth embodiment. A seventh valve (197); and an eighth valve (198) for adjusting 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 in this embodiment does not include the first additional line (L6), and the second supply line (L2) branched from the first supply line (L1) is a recirculation line. Instead of (L5), it merges again with the first supply line (L1). In addition, after the recirculation line (L5) is branched from the second supply line (L2) between the second cooler (132) and the fourth valve (194) instead of the first supply line (L1). , Not the first supply line (L1) but the second supply line (L2) between the third valve (193) and the second compressor (122) is joined again.

  Further, unlike the fourth embodiment, the ship in this embodiment does not include the sixth valve (196).

  In the present embodiment, the first compressor (120) includes the first heat exchanger (110), and after the evaporated gas discharged from the storage tank (T) is heat-exchanged by the first heat exchanger (110). Or although the case where it supplied to the 2nd compressor (122) was demonstrated, the ship of this invention is not equipped with the 1st heat exchanger (110), and the evaporation gas discharged | emitted from the storage tank (T) is immediately. The evaporative gas supplied to the first compressor (120) or the second compressor (122) and undergoing the reliquefaction process along the return line (L3) is compressed by the propulsion compressor (126) and immediately becomes the second heat. It can also be sent to the exchanger (140). The same applies to a sixth embodiment described later.

  In the present embodiment, the fluid circulating along the recirculation line (L5) first passes through the second heat exchanger (140) and is expanded by the refrigerant decompression device (160), and then the second again. Although the case where it supplies with a heat exchanger (140) was demonstrated, the fluid which circulates along the recirculation line (L5) of this invention is branched from the 2nd supply line (L2), and is immediately refrigerant | coolant decompression apparatus (160). ) Can be sent to the second heat exchanger (140). The same applies to a sixth embodiment described later.

  The first to fifth valves, the seventh to ninth valves, the eleventh valve and the twelfth valve (191, 192, 193, 194, 195, 197, 198, 201, 203, 205) of this embodiment are A person can directly determine the operation status and adjust it manually, or automatically adjust it so that it is opened and closed according to a preset value.

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

  In order to operate the refrigerant cycle of the ship in this embodiment in a closed loop, first, the first valve (191), the second valve (192), the third valve (193), the fourth valve (194), the fifth valve ( 195), the system is driven with the ninth valve (201) and the twelfth valve (205) opened.

  When the evaporated gas discharged from the storage tank (T) and compressed by the second compressor (122) is supplied to the recirculation line (L5), the third valve (193) and the fourth valve (194) are closed. The evaporative gas flows into 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), forming a closed-loop refrigerant cycle that circulates through the additional compressor (124), the additional cooler (134), and the ninth valve (201).

  When the refrigerant cycle is configured in a closed loop, nitrogen gas can be used as a refrigerant circulating in the closed loop. In this case, the storage tank (T) of this embodiment further includes piping for introducing nitrogen gas into the closed-loop refrigerant cycle.

  When the refrigerant cycle is operated in a closed loop, only the evaporated gas circulating in the closed loop is used as a refrigerant in the second heat exchanger (140), and the evaporated gas that has passed through the first compressor (120) is introduced into the refrigerant cycle. And cannot be supplied to the fuel customer (180) or undergo a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction and the amount of evaporated gas required at the fuel demand destination (180), a constant flow rate of evaporated gas is circulated as the refrigerant of the second heat exchanger (140).

  When the refrigerant cycle of this embodiment is operated in a closed loop, the flow rates of the evaporative gas used as a refrigerant and the evaporative gas used as the refrigerant are controlled compared to the case where the refrigerant cycle is operated in an open loop or an independent open loop. There is an advantage that it is easy to do.

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

  The evaporative gas discharged from the storage tank (T) passes through the first heat exchanger (110), is compressed by the first compressor (120), and is cooled by the first cooler (130). A part is sent to the fuel demand destination (180), and the remaining part goes through a reliquefaction process along the return line (L3).

  The evaporated gas discharged from the storage tank (T) and passed through the first heat exchanger (110) is about 1 bar, and the evaporated gas of about 1 bar is compressed by the first compressor (120) to about 17 bar. Can be. The pressure of the evaporative gas compressed by the first compressor (120) is variable depending on the reliquefaction performance required by the system and the operation status of the system.

  The evaporative gas that has undergone the reliquefaction process along the return line (L3) is compressed by the propulsion compressor (126) and cooled by the propulsion cooler (136), and then stored in the storage tank by the first heat exchanger (110). Heat is exchanged with the evaporating gas discharged from (T) to cool. The evaporative gas cooled by the first heat exchanger (110) is heat-exchanged by the second heat exchanger (140), further cooled, and then expanded by the first decompression device (150). Reliquefied.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the partially or wholly reliquefied evaporative gas is immediately sent to the storage tank (T), and the ship in the present embodiment performs the gas-liquid separation. When the vessel (170) is provided, the partially or wholly reliquefied evaporative gas is sent to the gas-liquid separator (170). The gas separated by the gas-liquid separator (170) merges with the evaporated gas discharged from the storage tank (T) and is sent to the first heat exchanger (110), where it is separated by the gas-liquid separator (170). The liquid is sent to the storage tank (T).

  On the other hand, the evaporative gas circulating in the refrigerant cycle is compressed by the additional compressor (124) and cooled by the additional cooler (134), and further compressed by the second compressor (122) to be compressed by the second cooler (122). 132) and sent to the second heat exchanger (140) along the recirculation line (L5). The evaporative gas sent to the second heat exchanger (140) through the additional compressor (124) and the second compressor (122) is primarily heat-exchanged by the second heat exchanger (140). Then, the refrigerant is sent to the refrigerant pressure reducing device (160) and secondarily expanded and cooled.

  The evaporative gas compressed by the additional compressor (124) is about 2 bar, and the evaporative gas of about 2 bar is compressed by the second compressor (122) to about 32 bar. The pressure of the evaporative gas compressed by the additional compressor (124) and the pressure of the evaporative gas compressed by the second compressor (122) are variable depending on the reliquefaction performance required by the system and the operation status of the system. It is.

  The evaporated gas that has passed through the refrigerant decompression device (160) is sent again to the second heat exchanger (140), passes through the first heat exchanger (110), and passes through the return line (L3) to perform the second heat exchange. Evaporative gas supplied to the condenser (140); and compressed by the additional compressor (124) and the second compressor (122) and supplied to the second heat exchanger (140) along the recirculation line (L5). It is used as a refrigerant for cooling the evaporated gas. The evaporative gas that has passed through the refrigerant pressure reducing device (160) and used as the refrigerant in the second heat exchanger (140) is sent again to the additional compressor (124), and the above-described series of processes is repeated.

  If the first compressor (120) or the first cooler (130) breaks down while the refrigerant cycle of the ship in this embodiment is operated in a closed loop, the first valve (191), the second valve (192), The ninth valve (201) and the twelfth valve (205) are closed, the third valve (193) and the fourth valve (194) are opened, and the first heat exchanger (110) is discharged from the storage tank (T). The evaporated gas that has passed through the gas passes through the third valve (193), the second compressor (122), the second cooler (132), and the fourth valve (194) and is supplied to the fuel demand destination (180). Configure as follows.

  FIG. 7 is a configuration diagram schematically showing an evaporative gas treatment system for a ship according to a sixth embodiment of the present invention.

  The ship in the sixth embodiment shown in FIG. 7 is installed on the second additional line (L11) and the second additional line (L11) as compared to the ship in the fifth embodiment shown in FIG. On the thirteenth valve (206), the third additional line (L12), the fourteenth valve (207), the fourth additional line (L13) and the fourth additional line (L13) installed on the third additional line (L12) There is a difference further provided with a fifteenth valve (208) installed in the above, and the difference will be mainly described below. Detailed description of the same members as those of the ship of the fifth embodiment described above will be omitted.

  Referring to FIG. 7, the ship in the present embodiment is similar to the fifth embodiment in that the first heat exchanger (110), the first valve (191), the first compressor (120), the first cooler ( 130), second valve (192), third valve (193), second compressor (122), second cooler (132), fourth valve (194), propulsion compressor (126), propulsion cooler (136), second heat exchanger (140), refrigerant decompression device (160), additional compressor (124), additional cooler (134), ninth valve (201), twelfth valve (205) and first A decompressor (150) is provided.

  As in the fifth embodiment, the first heat exchanger (110) of the present embodiment uses the evaporative gas discharged from the storage tank (T) as a refrigerant and uses the first heat exchanger (110) along the return line (L3). The evaporated gas sent by the heat exchanger (110) is cooled. That is, the first heat exchanger (110) collects the cold heat of the evaporated gas discharged from the storage tank (T), and the collected cold heat is returned to the first heat exchanger (110) along the return line (L3). The evaporative gas sent to is supplied. A fifth valve (195) for adjusting the flow rate and opening / closing of the evaporating gas may be installed on the return line (L3).

  As in the fifth embodiment, the first compressor (120) of the present embodiment is installed on the first supply line (L1) and compresses the evaporated gas discharged from the storage tank (T). The second compressor (122) of the example was installed in parallel with the first compressor (120) on the second supply line (L2) and discharged from the storage tank (T) as in the fifth embodiment. Compress the evaporative gas. The first compressor (120) and the second compressor (122) are compressors having the same performance, and are multistage compressors.

  The 1st compressor (120) and the 2nd compressor (122) of a present Example can compress evaporative gas to the pressure which a fuel consumer (180) requires similarly to 5th Example. Further, when the fuel demand destination (180) includes a plurality of types of engines, after the evaporated gas is compressed in accordance with the required pressure of an engine that requires a higher pressure (hereinafter referred to as “high pressure engine”). , A part is supplied to a high-pressure engine, and the other part is decompressed by a decompression device installed upstream of an engine that requires lower pressure (hereinafter referred to as “low-pressure engine”), and then the low-pressure engine. Can be supplied to. In addition, in order to increase the reliquefaction efficiency and the reliquefaction amount in the first heat exchanger (110) and the second heat exchanger (140), the evaporative gas is supplied to the first compressor (120) or the second compressor ( 122) is compressed at a pressure higher than the pressure required by the fuel consumer (180), and a decompression device is installed upstream of the fuel consumer (180), and the pressure of the evaporated gas compressed at the high pressure is reduced to the fuel consumer. After the pressure is reduced to the pressure required by (180), the fuel can be supplied to the customer (180).

  As in the fifth embodiment, the ship in the present embodiment is installed upstream of the fuel demand destination (180), and an eleventh valve for adjusting the flow rate and opening / closing of the evaporative gas sent to the fuel demand destination (180) ( 203).

  The 1st cooler (130) of a present Example is installed in the downstream of the 1st compressor (120) similarly to 5th Example, and not only pressure is passing through the 1st compressor (120). The evaporated gas whose temperature has risen is cooled. As in the fifth embodiment, the second cooler (132) of the present embodiment is installed downstream of the second compressor (122), and not only the pressure while passing through the second compressor (122). The evaporated gas whose temperature has risen is cooled.

  The propulsion compressor (126) of the present embodiment is installed on the return line (L3) and supplied to the first heat exchanger (110) along the return line (L3) as in the fifth embodiment. Increase evaporative gas pressure. The propulsion compressor (126) can compress the evaporated gas to a pressure below a critical point (about 55 bar in the case of methane) and to a pressure exceeding the critical point. If the machine (126) compresses the evaporative gas above the critical point, it can be compressed to about 300 bar.

  As in the fifth embodiment, the propulsion cooler (136) of the present embodiment is installed on the return line (L3) downstream of the propulsion compressor (126) and passes through the propulsion compressor (126). Reduce the temperature of the evaporating gas that has risen not only in pressure but also in temperature.

  Since the ship in the present embodiment further includes a propulsion compressor (126), similarly to the fifth embodiment, it is possible to increase the reliquefaction amount and the reliquefaction efficiency by increasing the pressure of the evaporative gas passing through the reliquefaction process. Therefore, the concept of redundancy can be sufficiently secured, and the operation cost can be reduced.

  Similarly to the fifth embodiment, the second heat exchanger (140) of the present embodiment is supplied to the first heat exchanger (110) along the return line (L3), and the first heat exchanger (110) The evaporative gas cooled by the above is further cooled.

  According to the present embodiment, as in the fifth embodiment, the evaporated gas discharged from the storage tank (T) is further cooled not only by the first heat exchanger (110) but also by the second heat exchanger (140). Thus, since it can be supplied to the first pressure reducing device (150) at a lower temperature, the reliquefaction efficiency and the reliquefaction amount are increased.

  Similarly to the fifth embodiment, the refrigerant decompression device (160) of the present embodiment expands the evaporated gas that has passed through the second heat exchanger (140), and then sends it again to the second heat exchanger (140). .

  The additional compressor (124) of this example was installed on the recirculation line (L5) and passed through the refrigerant pressure reducing device (160) and the second heat exchanger (140), as in the fifth example. Compress the fluid. Further, the additional compressor (124) of the present embodiment is driven by the power produced by the refrigerant decompression device (160) while expanding the fluid, as in the fifth embodiment, and is added to the refrigerant decompression device (160). The machine (124) can form a compander (Compander, 900). The additional compressor (124) may have a smaller capacity than the second compressor (122) and a capacity that can be driven by the power produced by the refrigerant pressure reducing 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 capacity is smaller than that of the first compressor (120) or the second compressor (122). By adding the additional compressor (124), the reliquefaction efficiency and reliquefaction amount can be increased at low cost.

  As in the fifth embodiment, the additional cooler (134) of this embodiment is installed downstream of the additional compressor (124) on the recirculation line (L5) and is compressed by the additional compressor (124). Reduce the temperature of the evaporating gas that has risen not only in pressure but also in temperature.

  In this embodiment, as in the fifth embodiment, the additional compressor (124) and the additional cooler (134) are installed on the recirculation line (L5), and are used as refrigerant in the second heat exchanger (140). When the first compressor (120) or the first cooler (130) fails while allowing the fluid to be used to circulate in the same path as the closed-loop refrigerant cycle of the fourth embodiment, from the fourth embodiment The evaporative gas that has passed through the second compressor (122) and the second cooler (132) can be easily supplied as fuel to the fuel customer (180). Further, as described later, while operating the system to supply the evaporated gas compressed by the second compressor (122) to the fuel demand destination (180), the second compressor (122) or the second compressor (122) is operated. When the second cooler (132) fails, the evaporated gas that has passed through the first compressor (120) and the first cooler (130) is supplied as fuel to the fuel demand destination (180) more easily than in the fourth embodiment. can do.

  As in the fifth embodiment, the first pressure reducing device (150) of the present embodiment is installed on the return line (L3) by the first heat exchanger (110) and the second heat exchanger (140). The cooled evaporative gas is expanded. The first decompression device (150) of the present embodiment includes all means capable of expanding and cooling the evaporative gas, and may be an expansion valve or an expander such as a Joule-Thomson valve.

  As in the fifth embodiment, the ship in this embodiment is installed on the return line (L3) downstream of the first decompression device (150), and the gas-liquid mixture discharged from the first decompression device (150) is removed. A gas-liquid separator (170) for separating the gas component and the liquid component can be provided.

  Similarly to the fifth embodiment, when the ship in this embodiment does not include the gas-liquid separator (170), the evaporated gas in the liquid state or the gas-liquid mixed state that has passed through the first pressure reducing device (150) is immediately When the ship in the present embodiment is provided with a gas-liquid separator (170), the evaporated gas that has passed through the first decompression device (150) is sent to the gas-liquid separator (170). And separated into a gas component and a liquid component. The liquid component separated by the gas-liquid separator (170) returns to the storage tank (T) along the return line (L3), and the gas component separated by the gas-liquid separator (170) 170) is supplied to the first heat exchanger (110) along a gas discharge line (L4) extending from the first heat exchanger (110) to the first supply line (L1) upstream of the first heat exchanger (110).

  When the ship in this embodiment includes a gas-liquid separator (170), the flow rate of the liquid separated by the gas-liquid separator (170) and sent to the storage tank (T) is adjusted, as in the fifth embodiment. A seventh valve (197); and an eighth valve (198) for adjusting the flow rate of the gas separated by the gas-liquid separator (170) and sent to the first heat exchanger (110).

  Moreover, the ship in a present Example does not contain a 1st additional line (L6) similarly to 5th Example, and the 2nd supply line (L2) branched from the 1st supply line (L1) is a 1st supply line. (L1) and the recirculation line (L5) branch from the second supply line (L2) between the second cooler (132) and the fourth valve (194), and then the third valve ( 193) and the second supply line (L2) between the second compressor (122).

  However, the ship in this embodiment differs from the fifth embodiment in the second additional line (L11); the thirteenth valve (206) installed on the second additional line (L11); the 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 this embodiment is branched from the recirculation line (L5) between the additional cooler (134) and the ninth valve (201), and the first valve (191) and the first valve It merges with the 1st supply line (L1) between compressors (120).

  The third additional line (L12) of this embodiment is branched from the first supply line (L1) between the first cooler (130) and the second valve (192), and the twelfth valve (205). Join the recirculation line (L5) between the second heat exchanger (140).

  The fourth additional line (L13) of this embodiment is branched from the second supply line (L2) between the second cooler (132) and the fourth valve (194), and the fifth valve (195). Join the return line (L3) to the propulsion compressor (126).

  According to this embodiment, unlike the fifth embodiment, both the first compressor (120) and the second compressor (122) are used to compress the evaporated gas supplied to the refrigerant cycle; The use of compressing the evaporative gas supplied to (180) can be selectively used. Further, according to the present embodiment, unlike the fifth embodiment, not only the evaporative gas branched from the first supply line (L1) but also the evaporative gas branched from the second supply line (L2) is selectively used. A reliquefaction process can be performed along the return line (L3).

  That is, according to the fifth embodiment, the evaporative gas compressed by the first compressor (120) at normal times is sent to the fuel demand destination (180) or undergoes a reliquefaction process along the return line (L3). The evaporative gas compressed by the second compressor (122) circulates through the refrigerant cycle, and the applications of the first compressor (120) and the second compressor (122) can be changed with each other. There wasn't.

  On the other hand, according to the present embodiment, either the first compressor (120) or the second compressor (122) is selected, and the evaporated gas is supplied to the fuel demand destination (180) or the return line (L3). Thus, the refrigerant cycle can be circulated by the evaporative gas compressed by another compressor that does not supply the evaporative gas to the fuel demand destination (180). Therefore, according to the present embodiment, there is an advantage that the operation of the system is free as compared with the fifth embodiment.

The first to fifth valves of the present embodiment, the seventh to ninth valve, 11 valve, second 15 valve (191,192,193,194,195,197,198,201,203,205,206, 207, 208) can be adjusted manually so that a person directly determines the operating status of the system and manually adjusts it so as to be opened and closed by a preset value.

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

  The refrigerant cycle of the ship in the present embodiment is operated in a closed loop, the evaporated gas compressed by the first compressor (120) is sent to the fuel demand destination (180), and the evaporation compressed by the second compressor (122) In order to circulate the refrigerant cycle with gas, first, the first valve (191), the second valve (192), the third valve (193), the fourth valve (194), the fifth valve (195), the ninth valve (201) and the twelfth valve (205) are opened, and the thirteenth valve (206), the fourteenth valve (207) and the fifteenth valve (208) are closed to drive the system.

  When the evaporated gas discharged from the storage tank (T) and compressed by the second compressor (122) is supplied to the recirculation line (L5), the third valve (193) and the fourth valve (194) are closed. The evaporative gas is discharged from the second compressor (122), the second cooler (132), the twelfth valve (205), the second heat exchanger (140), the refrigerant pressure reducing device (160), and the second heat exchanger again. (140), an additional compressor (124), an additional cooler (134), and a ninth valve (201) are circulated to form a closed loop refrigerant cycle.

  When the refrigerant cycle is configured in a closed loop, nitrogen gas can be used as a refrigerant circulating in the closed loop. In this case, the storage tank (T) of the present embodiment can further include piping for introducing nitrogen gas into the closed-loop refrigerant cycle.

  When the refrigerant cycle is operated in a closed loop, only the evaporated gas circulating in the closed loop is used as a refrigerant in the second heat exchanger (140), and the evaporated gas that has passed through the first compressor (120) is introduced into the refrigerant cycle. Cannot be supplied to the fuel customer (180) or undergo a reliquefaction process along the return line (L3). Therefore, regardless of the amount of reliquefaction and the amount of evaporated gas required at the fuel demand destination (180), a constant flow rate of evaporated gas is circulated as the refrigerant of the second heat exchanger (140).

  When the refrigerant cycle of the present embodiment is operated in a closed loop, compared to the case where the refrigerant cycle is operated in an open loop or an independent open loop, the control of the respective flow rates of the evaporative gas used as a refrigerant and the evaporative gas used as the refrigerant Has the advantage of being easy.

  The refrigerant cycle of the ship in this embodiment is operated in a closed loop, the evaporated gas compressed by the first compressor (120) is sent to the fuel demand destination (180), and the evaporated gas compressed by the second compressor (122) When the refrigerant cycle is circulated, the flow of the evaporative gas will be described as follows.

  The evaporative gas discharged from the storage tank (T) passes through the first heat exchanger (110), is compressed by the first compressor (120), and is cooled by the first cooler (130). A part is sent to the fuel demand destination (180), and the remaining part goes through a reliquefaction process along the return line (L3).

  The evaporated gas discharged from the storage tank (T) and passed through the first heat exchanger (110) is about 1 bar, and the evaporated gas of about 1 bar is compressed by the first compressor (120) to about 17 bar. Become. The pressure of the evaporative gas compressed by the first compressor (120) is variable depending on the reliquefaction performance required from the system and the operation status of the system.

  The evaporative gas that has undergone the reliquefaction process along the return line (L3) is compressed by the propulsion compressor (126) and cooled by the propulsion cooler (136), and then stored in the storage tank by the first heat exchanger (110). Heat is exchanged with the evaporating gas discharged from (T) to cool. The evaporative gas cooled by the first heat exchanger (110) is heat-exchanged by the second heat exchanger (140) and further cooled, and then expanded by the first decompression device (150) to be partially or completely. Is reliquefied.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the partially or wholly reliquefied evaporative gas is immediately sent to the storage tank (T), and the ship in the present embodiment performs the gas-liquid separation. When the vessel (170) is provided, the partially or wholly reliquefied evaporative gas is sent to the gas-liquid separator (170). The gas separated by the gas-liquid separator (170) merges with the evaporated gas discharged from the storage tank (T) and is sent to the first heat exchanger (110), where it is separated by the gas-liquid separator (170). The liquid is sent to the storage tank (T).

  On the other hand, the evaporative gas circulating in the refrigerant cycle is compressed by the additional compressor (124) and cooled by the additional cooler (134), and further compressed by the second compressor (122) to be compressed by the second cooler (122). 132) and sent to the second heat exchanger (140) along the recirculation line (L5). The evaporative gas sent to the second heat exchanger (140) through the additional compressor (124) and the second compressor (122) is primarily heat-exchanged by the second heat exchanger (140). Then, the refrigerant is sent to the refrigerant pressure reducing device (160) and secondarily expanded and cooled.

  The evaporative gas compressed by the additional compressor (124) is about 2 bar, and the evaporative gas of about 2 bar is compressed by the second compressor (122) to about 32 bar. The pressure of the evaporative gas compressed by the additional compressor (124) and the pressure of the evaporative gas compressed by the second compressor (122) are variable depending on the reliquefaction performance required by the system and the operation status of the system. It is.

  The evaporated gas that has passed through the refrigerant decompression device (160) is sent again to the second heat exchanger (140), passes through the first heat exchanger (110), and passes through the return line (L3) to perform the second heat exchange. Evaporative gas supplied in the condenser (140); and compressed by the additional compressor (124) and the second compressor (122) and supplied to the second heat exchanger (140) along the recirculation line (L5). It is used as a refrigerant for cooling the evaporated gas. The evaporative gas that has passed through the refrigerant pressure reducing device (160) and used as the refrigerant in the second heat exchanger (140) is sent again to the additional compressor (124), and the above-described series of processes is repeated.

  The refrigerant cycle of the ship in the present embodiment is operated in a closed loop, the evaporated gas compressed by the first compressor (120) is sent to the fuel demand destination (180), and the evaporation compressed by the second compressor (122) If the first compressor (120) or the first cooler (130) fails while circulating the refrigerant cycle with gas, the first valve (191), the second valve (192), the fifth valve (195), The ninth valve (201) and the twelfth valve (205) are closed, the third valve (193) and the fourth valve (194) are opened, and the first heat exchanger (110) is discharged from the storage tank (T). The evaporative gas that has passed through is supplied to the fuel demand destination (180) through the third valve (193), the second compressor (122), the second cooler (132), and the fourth valve (194). Configure.

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

  When the evaporated gas discharged from the storage tank (T) and compressed by the first compressor (120) is supplied to the recirculation line (L5) along the third additional line (L12), the first valve ( 191) and the second valve (192) are closed, and the evaporating gas becomes the first compressor (120), the first cooler (130), the fourteenth valve (207), the second heat exchanger (140), the refrigerant pressure reduction. A closed loop refrigerant cycle is circulated through the device (160), again the second heat exchanger (140), the additional compressor (124), the additional cooler (134) and the thirteenth valve (206).

  The refrigerant cycle of the ship in the present embodiment is operated in a closed loop, the evaporated gas compressed by the second compressor (122) is sent to the fuel demand destination (180), and the evaporation compressed by the first compressor (120) When the refrigerant cycle is circulated with gas, the flow of the evaporative gas will be described as follows.

  The evaporative gas discharged from the storage tank (T) passes through the first heat exchanger (110), is compressed by the second compressor (122), and is cooled by the second cooler (132). , A part is sent to the fuel customer (180), and the remaining part passes through the fifteenth valve (208) and undergoes a reliquefaction process along the return line (L3).

  Evaporated gas discharged from the storage tank (T) and passed through the first heat exchanger (110) is about 1 bar, and about 1 bar of evaporated gas is compressed by the second compressor (122) to about 17 bar. . The pressure of the evaporative gas compressed by the second compressor (122) is variable depending on the reliquefaction performance required by the system and the operation status of the system.

  The evaporative gas that has undergone the reliquefaction process along the return line (L3) is compressed by the propulsion compressor (126) and cooled by the propulsion cooler (136), and then stored in the storage tank by the first heat exchanger (110). Heat is exchanged with the evaporating gas discharged from (T) to cool. The evaporative gas cooled by the first heat exchanger (110) is subjected to heat exchange by the second heat exchanger (140) and further cooled, and then expanded by the first decompression device (150), and a part or all of it is expanded. Reliquefied.

  When the ship in the present embodiment does not include the gas-liquid separator (170), the partially or wholly reliquefied evaporative gas is immediately sent to the storage tank (T), and the ship in the present embodiment performs the gas-liquid separation. When the vessel (170) is provided, the partially or wholly reliquefied evaporated gas is sent to the gas-liquid separator (170). The gas separated by the gas-liquid separator (170) merges with the evaporating gas discharged from the storage tank (T), is sent to the first heat exchanger (110), and is separated by the gas-liquid separator (170). The liquid is sent to the storage tank (T).

  On the other hand, the evaporative gas circulating in the refrigerant cycle is compressed by the additional compressor (124) and cooled by the additional cooler (134), and then further compressed by the first compressor (120) to become the first cooler ( 130) and passed through the fourteenth valve (207) and sent to the second heat exchanger (140) along the recirculation line (L5). The evaporative gas sent to the second heat exchanger (140) through the additional compressor (124) and the first compressor (120) is primarily heat-exchanged by the second heat exchanger (140). Then, the refrigerant is sent to the refrigerant pressure reducing device (160) and secondarily expanded and cooled.

  The evaporative gas compressed by the additional compressor (124) is about 2 bar, and the evaporative gas of about 2 bar is compressed by the first compressor (120) to about 32 bar. The pressure of the evaporative gas compressed by the additional compressor (124) and the pressure of the evaporative gas compressed by the first compressor (120) are variable depending on the reliquefaction performance required by the system and the operation status of the system. It is.

  The evaporated gas that has passed through the refrigerant decompression device (160) is sent again to the second heat exchanger (140), passes through the first heat exchanger (110), and passes through the return line (L3) to perform the second heat exchange. Evaporative gas supplied in the condenser (140); and compressed by the additional compressor (124) and the first compressor (120) and supplied to the second heat exchanger (140) along the recirculation line (L5). It is used as a refrigerant for cooling the evaporated gas. The evaporative gas that has passed through the refrigerant pressure reducing device (160) and used as the refrigerant in the second heat exchanger (140) is sent again to the additional compressor (124), and the above-described series of processes is repeated.

  The refrigerant cycle of the ship in the present embodiment is operated in a closed loop, the evaporated gas compressed by the second compressor (122) is sent to the fuel demand destination (180), and the evaporation compressed by the first compressor (120) If the second compressor (122) or the second cooler (132) fails while circulating the refrigerant cycle through the gas, the third valve (193), the fourth valve (194), the thirteenth valve (206), The fourteenth valve (207) and the fifteenth valve (208) are closed, the first valve (191) and the second valve (192) are opened, and the first heat exchanger (110) is discharged from the storage tank (T). The evaporative gas that has passed through 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). Configure.

  The present invention is not limited to the above-described embodiments, and those having ordinary knowledge in the technical field to which the present invention belongs can be implemented with various changes or modifications within the scope not exceeding the technical gist of the present invention. It is self-evident.

Claims (22)

In a ship equipped with a liquefied gas storage tank,
A first compressor capable of compressing at least part of the evaporated gas discharged from the storage tank;
A second compressor for compressing another part of the evaporated gas discharged from the storage tank;
A propulsion compressor that compresses a portion 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 decompression device that expands another part of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A second heat exchanger that cools the evaporative gas compressed by the propulsion compressor and heat-exchanged by the first heat exchanger using the fluid expanded by the refrigerant decompression device as a refrigerant;
An additional compressor that compresses the refrigerant that has passed through the refrigerant decompression device and the second heat exchanger; and a fluid that is compressed by the propulsion compressor and cooled by the first heat exchanger and the second heat exchanger. A first decompression device for expansion;
The said additional compressor is driven by the motive power which the said refrigerant decompression device produces, expanding a fluid, The ship characterized by the above-mentioned. The propulsion compressor compresses only the evaporated gas compressed by the first compressor,
The ship according to claim 1, wherein the refrigerant decompression device expands only the evaporative gas compressed by the second compressor.   The ship according to claim 2, wherein the additional compressor compresses the refrigerant that has passed through the second heat exchanger and sends the compressed refrigerant to the second compressor.   The ship according to claim 2, wherein the additional compressor compresses the refrigerant that has passed through the second heat exchanger and sends the compressed refrigerant to the first compressor and the second compressor. The propulsion compressor compresses a part of the evaporated gas compressed by the first compressor and the second compressor,
The ship according to claim 1, wherein the refrigerant decompression device expands another part of the evaporated gas compressed by the first compressor and the second compressor.   The said 2nd heat exchanger can cool the fluid before passing through the said refrigerant | coolant decompression device with the refrigerant | coolant expanded by the said refrigerant | coolant decompression device, It is any one of Claim 1 thru | or 5 characterized by the above-mentioned. Ship. A gas-liquid separator that separates the liquefied gas and the evaporated gas from the fluid that has passed through the first decompression device;
The ship according to any one of claims 1 to 5, wherein the liquefied gas separated by the gas-liquid separator is sent to the storage tank.   6. The other part of the evaporative gas compressed by at least one of the first compressor and the second compressor is supplied to a fuel demand destination. A ship according to any one of the above.   The marine vessel according to claim 3, wherein the refrigerant circulates through at least the additional compressor, the second compressor, the refrigerant decompression device, and the second heat exchanger to form a closed loop refrigerant cycle. . In a ship equipped with a liquefied gas storage tank,
A first compressor capable of compressing at least part of the evaporated gas discharged from the storage tank;
A second compressor for compressing another part of the evaporated gas discharged from the storage tank;
A propulsion compressor that compresses a portion of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A refrigerant decompression device that expands another part of the evaporated gas compressed by at least one of the first compressor and the second compressor;
A second heat exchanger that cools the evaporative gas compressed by the propulsion compressor using the fluid expanded by the refrigerant decompression device as a refrigerant;
An additional compressor that compresses the refrigerant that has passed through the refrigerant decompression device and the second heat exchanger; and a first decompression device that expands the fluid compressed by the propulsion compressor and cooled by the second heat exchanger; With
The said additional compressor is driven by the motive power which the said refrigerant decompression device produces, expanding a fluid, The ship characterized by the above-mentioned. In a ship's evaporative gas treatment system having a storage tank for storing liquefied gas,
A first supply line for sending a part of the evaporated gas discharged from the storage tank to a fuel demand destination after being compressed by a first compressor;
A second supply line branched from the first supply line and compressing another part of the evaporated gas discharged from the storage tank by a second compressor;
A return line branched from the first supply line and further compressed by a propulsion compressor and then re-liquefied by passing through the first heat exchanger, the second heat exchanger, and the first pressure reducing device. ;
A recirculation line for passing evaporative gas cooled by passing through the second heat exchanger and the refrigerant pressure reducing device to the second heat exchanger and using it as a refrigerant; and installed upstream of the second compressor. An additional compressor for compressing the evaporative gas;
The additional compressor is driven by the power produced by the refrigerant decompression device while expanding the fluid,
The first heat exchanger uses the evaporated gas discharged from the storage tank as a refrigerant, heats the evaporated gas compressed by the propulsion compressor and supplied along the return line, and cools it,
The second heat exchanger uses both the evaporative gas that has passed through the refrigerant decompression device as a refrigerant, the evaporative gas that is supplied along the recirculation line; and the evaporative gas that is supplied along the return line; An evaporative gas treatment system for a ship, characterized in that heat is exchanged for cooling.   The evaporative gas treatment system for a ship according to claim 11, wherein the additional compressor is installed on the second supply line.   The said additional compressor is installed on the said recirculation line downstream of the said refrigerant | coolant decompression device and the said 2nd heat exchanger, The evaporative gas processing system of the ship of Claim 11 characterized by the above-mentioned.   The first and second additional lines that connect between the refrigerant decompression device and the recirculation line downstream of the second heat exchanger and the second supply line upstream of the second compressor. 12. The ship's evaporative gas treatment system according to 12.   After evaporating gas passes through the additional compressor, the second compressor, the second heat exchanger, the refrigerant decompression device, and the second heat exchanger again, the first additional line passes again, 15. The ship's evaporative gas treatment system according to claim 14, wherein the ship's evaporative gas treatment system is supplied to an additional compressor to form a closed-loop refrigerant cycle. The evaporative gas compressed by the first compressor and the evaporative gas compressed by the second compressor merge,
A portion is reliquefied along the return line,
The other part passes through the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger again along the recirculation line, and then is discharged from the storage tank to be the first heat exchange. The fluid that has passed through the vessel
15. The evaporative gas treatment system for a ship according to claim 14, wherein the remaining part is supplied to the fuel demand destination. The evaporative gas compressed by the first compressor is partly reliquefied along the return line, and the remaining part is supplied at the fuel demand destination.
The evaporative gas compressed by the second compressor passes through the second heat exchanger, the refrigerant pressure reducing device, and the second heat exchanger again along the recirculation line, and then is discharged from the storage tank. The ship evaporative gas treatment system according to claim 14, wherein the evaporative gas treatment system merges with the fluid that has passed through the first heat exchanger.   The evaporative gas circulates through the second compressor, the second heat exchanger, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor again to form a closed-loop refrigerant cycle. The ship's evaporative gas treatment system according to claim 13. A second additional line branched from a recirculation line downstream of the additional compressor and connected to the first supply line upstream of the first compressor;
A third additional line branched from a first supply line downstream of the first compressor and connected to a recirculation line upstream of the refrigerant decompression device and the second heat exchanger; and of the second compressor The ship's evaporative gas treatment system according to claim 13, further comprising: a fourth additional line branched from a downstream second supply line and connected to the return line upstream of the propulsion compressor.   After evaporating gas is compressed by the second compressor, it passes through the second heat exchanger, the refrigerant pressure reducing device, the second heat exchanger, and the additional compressor along the recirculation line. The ship evaporative gas treatment system according to claim 19, wherein the second compressor is supplied again to form a closed-loop refrigerant cycle.   After the evaporative gas is compressed by the first compressor, the evaporative gas is supplied to the second heat exchanger along the third additional line and the recirculation line, and the refrigerant pressure reducing device is again supplied to the second heat exchange. The ship of claim 19, wherein the vessel is passed through a compressor and the additional compressor and is supplied again to the first compressor along the second additional line to form a closed-loop refrigerant cycle. Evaporative gas treatment system. The evaporation gas discharged from the liquefied gas storage tank is branched into two, one flow of the branched evaporation gas is compressed by the first compressor, and the other flow is compressed by the second compressor,
The evaporative gas compressed by the first compressor is further compressed by a propulsion compressor, then reliquefied and returned to the storage tank,
The evaporative gas compressed by the second compressor is used as a refrigerant for circulating the refrigerant cycle and cooling the evaporative gas compressed by the first compressor,
The fluid circulating in the refrigerant cycle is compressed by an additional compressor and supplied to the second compressor.

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