Cryogenic compression equipment and boil-off gas liquefaction system including same

Abstract

This cryogenic compression equipment comprises: a compressor including a suction port for sucking a cryogenic fluid, a compression unit for compressing the cryogenic fluid to be sucked, and a discharge port for discharging the compressed fluid; and a heating device for heating the compressed fluid discharged from the discharge port.

Description

Cryogenic compression equipment and boil-off gas liquefaction system equipped with the same

[0001] The present invention relates to a cryogenic compression facility for compressing a cryogenic fluid, and a boil-off gas liquefaction system including the same.

[0002] In a storage facility having a tank for storing a cryogenic liquid such as liquefied hydrogen, a compressor is provided to compress the gas. For example, Patent Document 1 discloses a compressor that compresses boil-off gas generated in the tank of the storage facility.

[0003] Japanese Patent Application Laid-Open No. 2023-177464

[0004] In a compressor, the lower the temperature of the gas taken in, the higher the compression efficiency. However, if the temperature of the gas taken in is too low, the temperature of the compressed gas discharged from the compressor may be lower than room temperature. In such cases, low-temperature measures are required downstream of the compressor discharge port, which increases costs.

[0005] Therefore, an object of the present invention is to provide a cryogenic compression facility that can improve compression efficiency and suppress cost increases, and a boil-off gas liquefaction system equipped with the same.

[0006] The cryogenic compression equipment of the present invention comprises a compressor including an intake port for drawing in a cryogenic fluid, a compression section for compressing the drawn in cryogenic fluid, and an outlet port for discharging the compressed compressed fluid, and a heating device for heating the compressed fluid discharged from the outlet port.

[0007] According to the present invention, a cryogenic fluid is drawn into the compressor through the intake port. This improves the compression efficiency of the compressor. Furthermore, the heating device heats the compressed fluid discharged from the compressor's discharge port. This increases the temperature of the compressed fluid. This reduces the need for low-temperature measures downstream of the discharge port, thereby reducing the cost of manufacturing cryogenic compression equipment. This improves the compression efficiency of cryogenic compression equipment while minimizing the cost.

[0008] The boil-off gas liquefaction system of the present invention comprises the above-mentioned cryogenic compression equipment and a liquefier that liquefies the compressed fluid discharged from the cryogenic compression equipment, and the cryogenic compression equipment sucks in boil-off gas, which is a cryogenic fluid generated by the evaporation of a cryogenic liquid in a liquid tank that stores the cryogenic liquid.

[0009] According to the present invention, the cryogenic compression equipment sucks in boil-off gas, which is a cryogenic fluid generated by vaporizing a cryogenic liquid in a liquid tank. The cryogenic compression equipment then compresses and discharges the boil-off gas, and the liquefier liquefies the compressed boil-off gas discharged from the cryogenic compression equipment. This makes it possible to construct a boil-off gas liquefaction system that can reuse the boil-off gas. Furthermore, as described above, this makes it possible to suppress an increase in the cost of the cryogenic compression equipment, thereby enabling the construction of a cost-effective boil-off gas liquefaction system.

[0010] According to the present invention, it is possible to improve compression efficiency and suppress an increase in cost.

[0011] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

[0012] 1 is a circuit diagram showing a boil-off gas liquefaction system according to a first embodiment.

[0014] FIG. 2 is a schematic diagram showing a cryogenic fluid compression facility provided in the boil-off gas liquefaction system of FIG.

[0013] Hereinafter, a boil-off gas liquefaction system (hereinafter referred to as a "BOG liquefaction system") 1 and a cryogenic fluid compression facility (hereinafter simply referred to as a "compression facility") 11 provided therein according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the concept of direction used in the following description is used for convenience of explanation and does not limit the orientation of the configuration of the invention to that direction. Furthermore, the boil-off gas liquefaction system 1 and the compression facility 11 provided therein described below are merely one embodiment of the present invention. Therefore, the present invention is not limited to the embodiment, and additions, deletions, and modifications are possible within the scope of the spirit of the invention.

[0014] [BOG Liquefaction System] The BOG liquefaction system 1 is provided in a liquefied gas storage facility 2, such as a liquefied gas shipping or receiving terminal, or a liquefied gas transport device (e.g., a tanker). The BOG liquefaction system 1 liquefies cryogenic boil-off gas generated by evaporation of liquefied gases such as liquefied hydrogen and liquefied helium. In this disclosure, "cryogenic temperature" refers to a temperature below the condensation temperature at which air is liquefied. Note that the cryogenic temperature range may be below the condensation temperature of oxygen and is not limited to the aforementioned temperature range. In this embodiment, the liquefied gas is liquefied hydrogen.

[0015] The liquefied gas storage facility 2 includes a liquefied hydrogen tank 3. Liquefied hydrogen is stored in the liquefied hydrogen tank 3, which is an example of a liquid tank. The liquefied gas storage facility 2 loads and unloads the liquefied hydrogen stored in the liquefied hydrogen tank 3 to a loading and unloading facility (not shown). For example, when the liquefied gas storage facility 2 is a shipping terminal, the liquefied gas storage facility 2 transfers the liquefied hydrogen stored in the liquefied hydrogen tank 3 via transfer piping 4 to a loading and unloading facility, such as a transportation device, which is the destination of the shipment. When the liquefied gas storage facility 2 is a receiving terminal, the liquefied gas storage facility 2 stores the liquefied hydrogen transferred from the transportation device, which is the loading and unloading facility at the shipping source, via transfer piping 4 in the liquefied hydrogen tank 3. In addition, between the liquefied gas storage facility 2 and the loading and unloading facility, boil-off gas is transferred via BOG piping 5 so that the liquefied hydrogen being transferred also flows in the reverse direction. Boil-off gas is a gas generated by evaporation of liquefied hydrogen in the liquefied gas storage facility 2 and the loading and unloading facility. In the liquefied gas storage facility 2, boil-off gas is generated mainly in the liquefied hydrogen tank 3. The BOG piping 5 is connected to the liquefied hydrogen tank 3, and boil-off gas is guided from the liquefied hydrogen tank 3 to the BOG piping 5. More specifically, the BOG piping 5 is connected to the return gas piping 6, and the boil-off gas is transferred via the BOG piping 5 and the return gas piping 6. Note that the return gas piping 6 does not necessarily have to be connected to the BOG piping 5, and may be directly connected to the liquefied hydrogen tank 3. Boil-off gas is not limited to being generated in the liquefied hydrogen tank 3, but is generated in any location in the liquefied gas storage facility 2 where liquefied gas accumulates or flows (for example, the transfer piping 4). The BOG liquefaction system 1 liquefies the boil-off gas described above to produce liquefied hydrogen. That is, the BOG liquefaction system 1 regenerates boil-off gas into liquefied hydrogen. For example, the BOG liquefaction system 1 returns the produced liquefied hydrogen to the liquefied hydrogen tank 3. The BOG liquefaction system 1 configured in this manner includes a compression facility 11, a boil-off gas tank 12, and a liquefier 13.

[0016] [Compression Equipment] The compression equipment 11, which is an example of a cryogenic fluid compression equipment, compresses cryogenic boil-off gas. The compression equipment 11 also heats the compressed boil-off gas. As shown in Fig. 2 , the compression equipment 11 includes a compressor 21 and a heating device 22. More specifically, the compression equipment 11 further includes a suction-side pipe 23, a discharge-side pipe 24, and a downstream-side pipe 25.

[0017] The suction side pipe 23 is connected to the BOG pipe 5. The BOG pipe 5 has a vacuum insulation structure. In this embodiment, the BOG pipe 5 is a vacuum double pipe that maintains the temperature of the boil-off gas flowing therethrough at an extremely low temperature. In addition, the return gas pipe 6 and the suction side pipe 23 are connected to the BOG pipe 5 so that they branch off from each other. The suction side pipe 23 also has a vacuum insulation structure. More specifically, the suction side pipe 23 is also a vacuum double pipe. This allows the suction side pipe 23 to also maintain the temperature of the boil-off gas flowing therethrough at an extremely low temperature.

[0018] The compressor 21 compresses the cryogenic boil-off gas to generate compressed gas. At this time, the temperature of the boil-off gas increases as it is compressed. More specifically, the temperature of the compressed gas increases from a cryogenic temperature to a low temperature as a result of compression by the compressor 21. The low temperature is, for example, between -100°C and -20°C. In this embodiment, the temperature of the compressed gas is between -90°C and -70°C. In this embodiment, the compressor 21 is an LH ２ The compressor 21 is a positive displacement compressor compatible with boil-off gas (liquefied hydrogen). However, the compressor 21 is not limited to a positive displacement compressor and may be a centrifugal compressor. The compressor 21 includes an intake port 21a, a compression section 21b, and a discharge port 21c. At least the compression section 21b of the compressor 21 is vacuum insulated. In this embodiment, the intake port 21a and the compression section 21b of the compressor 21 are vacuum insulated. Therefore, the compressor 21 can withstand the use of extremely low temperature boil-off gas. The compressor 21 can compress extremely low temperature boil-off gas while suppressing liquefaction of air contained in the surrounding atmosphere.

[0019] The suction port 21a draws in cryogenic boil-off gas. More specifically, the suction port 21a is connected to the suction-side piping 23. The suction port 21a is connected to the suction-side piping 23 by, for example, a bayonet joint. The suction port 21a is also connected to the BOG piping 5 via the suction-side piping 23, and is further connected to the liquefied hydrogen tank 3 via the BOG piping 5. The boil-off gas generated in the liquefied hydrogen tank 3 is introduced to the suction port 21a via the BOG piping 5 and the suction-side piping 23.

[0020] The compression section 21b compresses the drawn-in cryogenic boil-off gas. The compression section 21b is connected to the suction-side piping 23 via the suction port 21a and draws in the cryogenic boil-off gas flowing through the suction-side piping 23. As described above, the compressor 21 is a positive displacement compressor, and the compression section 21b includes, for example, a cylinder 31, a piston 32, and a driving source 33. The cylinder 31 has, for example, a vacuum insulation structure and guides the drawn-in cryogenic boil-off gas into a bore 31a therein. The piston 32 is inserted into the bore 31a in the cylinder 31 so as to be capable of reciprocating. The driving source 33 is, for example, an electric motor and drives the piston 32 to reciprocate. The compression section 21b compresses the cryogenic boil-off gas guided to the bore 31a by reciprocating the piston 32 using the driving source 33. Furthermore, the compression increases the temperature of the boil-off gas. In this embodiment, the boil-off gas increases in temperature from cryogenic to low temperatures.

[0021] The discharge port 21c discharges compressed gas (i.e., compressed boil-off gas), which is an example of a compressed fluid. More specifically, the discharge port 21c is connected to the discharge-side piping 24, which will be described in detail later. In this embodiment, the discharge port 21c is connected to the discharge-side piping 24 by, for example, a flange joint. However, the method of connecting the discharge port 21c and the discharge-side piping 24 is not limited to a flange joint, and other joints such as a bayonet joint may also be used. The discharge port 21c discharges the boil-off gas compressed in the compression section 21b to the discharge-side piping 24.

[0022] The discharge-side pipe 24 is connected to the discharge port 21c. In this embodiment, the discharge-side pipe 24 has a heat-insulating structure. The discharge-side pipe 24 includes a pipe section 24a and a covering member 24b. The pipe section 24a is connected to the discharge port 21c. In this embodiment, the pipe section 24a is connected to the discharge port 21c by, for example, a flange joint. The low-temperature compressed gas discharged from the discharge port 21c flows through the pipe section 24a. The covering member 24b has heat-insulating properties and covers the pipe section 24a. More specifically, the covering member 24b covers the entire periphery of the pipe section 24a. The covering member 24b is made of, for example, a foamed resin having heat-insulating properties. In this embodiment, the covering member 24b is made of PUF (polyurethane foam). However, the covering member 24b is not limited to being made of PUF, and may be made of any material having heat-insulating properties. Note that the covering member 24b has lower heat-insulating properties than a vacuum double pipe. That is, the covering member 24b inputs more heat into the boil-off gas flowing inside the piping portion 24a than the vacuum double piping.

[0023] The heating device 22 heats the compressed gas discharged from the discharge port 21c. In this embodiment, the heating device 22 is provided in the discharge-side piping 24. The heating device 22 heats the low-temperature compressed gas flowing from the discharge-side piping 24. More specifically, the heating device 22 heats the boil-off gas to within the operating temperature limit range of the downstream-side piping 25, which will be described in detail later. In this embodiment, the heating device 22 heats the boil-off gas to room temperature or nearby. Room temperature is, for example, 5°C or higher and 35°C or lower. However, room temperature is just an example, and the temperature is not limited to the above-mentioned range.

[0024] The heating device 22 is a heat exchanger through which a heat medium flows. More specifically, the heating device 22 exchanges heat between the compressed gas and a heat medium (e.g., water). This heats the boil-off gas. On the other hand, the heat medium is cooled and reused in a cooler or the like. Note that the heat medium does not necessarily need to be reused, and the heat may be released into the atmosphere. The heating device 22 is not limited to a heat exchanger, and may be an electric heating coil, a heater, or the like. In this case, the heating device 22 may be attached to the exterior of the piping portion 24a of the discharge-side piping 24, for example, or embedded in the covering member 24b.

[0025] The downstream pipe 25 is connected downstream of the discharge pipe 24. In this embodiment, the downstream pipe 25 is connected downstream of the discharge pipe 24 via a heating device 22. Note that if the heating device 22 is provided on the outer circumferential surface of the discharge pipe 24, such as an electric heating coil or heater, the downstream pipe 25 may be directly connected to the discharge pipe 24. The downstream pipe 25 is a pipe whose service limit temperature range is higher than the low temperature. The service limit temperature range of the downstream pipe 25 includes room temperature. Therefore, low-temperature countermeasures for the downstream pipe 25 can be more relaxed, and the downstream pipe 25 can be manufactured at low cost. Note that, as an example of low-temperature countermeasures, for example, the low-temperature service limit temperature restrictions on the material used for the downstream pipe 25 are relaxed. Therefore, the design freedom for the downstream pipe 25 is improved, and low-cost materials can be used for the downstream pipe 25. In this embodiment, the downstream pipe 25 is a pipe made of carbon steel. Carbon steel is a material that can be used as a material for pipes through which hydrogen flows and is relatively inexpensive. The limit temperature range for use of carbon steel is -10°C to 350°C. However, the limit temperature range for use of carbon steel is not limited to the range described above. Compressed gas heated by the heating device 22, in this embodiment, compressed gas at room temperature, flows through the downstream pipe 25.

[0026] [Boil-off gas tank] As shown in Fig. 1 , the boil-off gas tank 12 stores compressed gas at room temperature. More specifically, the boil-off gas tank 12 is connected to the downstream piping 25. In this embodiment, the boil-off gas tank 12 is connected to the downstream piping 25 so as to be parallel to the liquefier 13, which will be described in detail later. Note that the boil-off gas tank 12 may be connected in series to the liquefier 13 via the downstream piping 25. The boil-off gas tank 12 temporarily stores the boil-off gas flowing through the downstream piping 25.

[0027] [Liquefier] The liquefier 13 liquefies the compressed gas discharged from the compression equipment 11. In this embodiment, the compressed gas liquefied by the liquefier 13 includes not only the compressed gas directly guided from the compression equipment 11 but also the compressed gas discharged from the compression equipment 11 and stored in the boil-off gas tank 12. The liquefier 13 is connected to the downstream piping 25. In this embodiment, the liquefier 13 is connected to the downstream piping 25 so as to be parallel to the boil-off gas tank 12. Therefore, compressed gas can be guided to the liquefier 13 directly from the compression equipment 11 or from the boil-off gas tank 12. The liquefier 13 liquefies the guided compressed gas. That is, the liquefier 13 produces liquefied hydrogen by cooling the compressed gas. The liquefier 13 is also connected to the regeneration piping 14 and is connected to the liquefied hydrogen tank 3 via the regeneration piping 14. The regeneration piping 14 has a vacuum insulation structure. In this embodiment, the regeneration piping 14 is a vacuum double piping. The liquefier 13 returns the liquefied hydrogen to the liquefied hydrogen tank 3 via a regeneration pipe 14 having a vacuum heat insulation structure, thereby regenerating the boil-off gas.

[0028] [Operation of the BOG Liquefaction System and Compression Equipment] Cryogenic boil-off gas is generated in the liquefied hydrogen tank 3, and the generated boil-off gas is discharged from the liquefied hydrogen tank 3 to the BOG piping 5. Except during loading and unloading, the BOG piping 5 is designed to flow mainly to the BOG liquefaction system 1, where the boil-off gas is regenerated. In the BOG liquefaction system 1, the boil-off gas generated in the liquefied hydrogen tank 3 is regenerated as follows. That is, the boil-off gas in the BOG piping 5 is guided to the suction side piping 23, and is sucked into the suction port 21a of the compressor 21 via the suction side piping 23. At this time, the boil-off gas is kept at a cryogenic temperature by the BOG piping 5 and the suction side piping 23, which have a vacuum insulation structure, and can be guided to the suction port 21a of the compressor 21 while still maintained at a cryogenic temperature.

[0029] In the compressor 21, the extremely low-temperature boil-off gas drawn in through the suction port 21a is compressed in the compression section 21b. That is, in the compressor 21, the drive source 33 reciprocates the piston 32, so that the extremely low-temperature boil-off gas is drawn into the bore 31a in the cylinder 31 from the suction port 21a and compressed. During compression, the extremely low-temperature boil-off gas is heated to a low temperature. The low-temperature compressed gas is then discharged from the discharge port 21c to the discharge-side pipe 24. The discharge-side pipe 24 has thermal insulation properties, which prevent the low-temperature compressed gas flowing therethrough from freezing around the discharge-side pipe 24. Meanwhile, the low-temperature compressed gas is guided to the heating device 22 via the discharge-side pipe 24.

[0030] The heating device 22 heats the low-temperature compressed gas. More specifically, the heating device 22 performs heat exchange between the low-temperature compressed gas and a heat medium. As a result, the temperature of the boil-off gas is raised to room temperature or near room temperature, and the boil-off gas is then sent to the downstream piping 25. In the downstream piping 25, the compressed gas is stored in the boil-off gas tank 12 or transferred to the liquefier 13. In the liquefier 13, the boil-off gas is regenerated into liquefied hydrogen. The liquefied hydrogen is then returned to the liquefied hydrogen tank 3.

[0031] In the compression equipment 11 of this embodiment, cryogenic boil-off gas is drawn in through the intake port 21a of the compressor 21. This improves the compression efficiency of the compressor 21. Furthermore, the heating device 22 heats the compressed gas discharged from the discharge port 21c of the compressor 21. This increases the temperature of the compressed gas. This reduces the need for low-temperature measures downstream of the discharge port 21c, thereby reducing the cost of manufacturing the compression equipment 11. This improves the compression efficiency of the compression equipment 11 and reduces the cost.

[0032] In the compression equipment 11 of this embodiment, the suction side pipe 23 is a vacuum insulated double pipe. Therefore, the boil-off gas can be drawn into the compressor 21 at a lower cryogenic temperature. This improves the compression efficiency of the compressor 21.

[0033] Furthermore, in the compression equipment 11 of this embodiment, the heating device 22 is provided on the discharge side pipe 24. Therefore, the degree of freedom in layout of the heating device 22 can be improved.

[0034] Furthermore, in the compression equipment 11 of this embodiment, the discharge-side pipe 24 includes the pipe portion 24a and the covering member 24b, which makes it possible to reduce costs related to low-temperature countermeasures.

[0035] Furthermore, in the compression equipment 11 of this embodiment, the heating device 22 heats the temperature of the compressed gas to within the operating temperature range of the downstream piping 25, which includes room temperature. This allows for easing the need for low-temperature countermeasures, thereby further reducing the cost of the compression equipment 11.

[0036] Furthermore, in the compression equipment 11 of this embodiment, the downstream piping 25 is made of carbon steel. Therefore, the cost of the downstream piping 25 can be kept low. This further reduces the cost of the compression equipment 11.

[0037] Furthermore, in the compression equipment 11 of this embodiment, the heating device 22 is a heat exchanger through which a heat medium flows, and heat is exchanged between the heat medium and the compressed gas. Therefore, the heating device 22 can absorb the cold energy in the compressed gas into the heat medium. This allows the cold energy to be reused via the heat medium.

[0038] In the BOG liquefaction system 1 of this embodiment, the compression equipment 11 sucks in cryogenic boil-off gas generated by vaporization of liquefied hydrogen in the liquefied hydrogen tank 3. The compression equipment 11 then compresses and discharges the boil-off gas, and the liquefier 13 liquefies the compressed gas discharged from the compression equipment 11. Therefore, it is possible to construct a BOG liquefaction system 1 that can reuse the boil-off gas. Furthermore, as described above, it is possible to suppress an increase in the cost of the compression equipment 11, so it is possible to construct a BOG liquefaction system 1 with reduced costs.

[0039] <Other Embodiments> In the BOG liquefaction system 1 of this embodiment, boil-off gas is cited as an example of the cryogenic fluid, but other cryogenic gases may also be used. Furthermore, the cryogenic fluid may be a mixture of liquid and gas, such as a mixture of liquefied hydrogen and boil-off gas. In the compression equipment 11 of this embodiment, the suction-side piping 23 and the suction port 21 a of the compressor 21 are connected by a bayonet joint, but they may also be connected by a flange joint, and the method of connecting the suction-side piping 23 and the suction port 21 a is not important. Furthermore, the suction-side piping 23 does not necessarily have to be a vacuum double pipe up to the end on the suction port 21 a side; the end on the suction port 21 a side and its vicinity may be a single pipe.

[0040] In the compression equipment 11 of this embodiment, the temperature of the compressed gas is raised to a low temperature by compression by the compressor 21, but it does not necessarily have to be raised to a low temperature. In this case, it is preferable that the discharge side pipe 24 is also a vacuum double pipe. However, the discharge side pipe 24 does not necessarily have to be a vacuum double pipe. Furthermore, although the compression equipment 11 of this embodiment includes a boil-off gas tank 12, it does not necessarily have to be included.

[0041] The compression equipment 11 of this embodiment does not necessarily have to be provided in the BOG liquefaction system 1, but may be applied to any equipment that requires compressing a cryogenic fluid. The compression equipment 11 does not necessarily have to transfer the compressed gas to the liquefier 13, but may supply the compressed gas to other equipment such as a power plant. Furthermore, the liquefied gas to be used is not limited to liquefied hydrogen, but may be other liquefied gases such as liquefied helium. Furthermore, the heating device 22 may be incorporated within the compressor 21 (for example, near the discharge port 21c, which is the outlet of the compression section 21b).

[0042] <Exemplary embodiment> A cryogenic compression facility in a first aspect includes a compressor including an intake port for sucking in a cryogenic fluid, a compression section for compressing the sucked in cryogenic fluid, and a discharge port for discharging the compressed compressed fluid, and a heating device for heating the compressed fluid discharged from the discharge port.

[0043] According to the above aspect, the cryogenic fluid is drawn into the suction port of the compressor. This improves the compression efficiency of the compressor. The heating device heats the compressed fluid discharged from the discharge port of the compressor. This increases the temperature of the compressed fluid. This reduces the need for low-temperature measures downstream of the discharge port, thereby reducing the cost increase when manufacturing cryogenic compression equipment. This improves the compression efficiency of the cryogenic compression equipment and reduces the cost increase.

[0044] In a second aspect, the cryogenic compression equipment of the first aspect further includes an intake side pipe connected to the intake port of the compressor, and the intake side pipe is a vacuum insulated double pipe.

[0045] According to the above aspect, the suction side piping is a vacuum insulated double piping, so that the cryogenic fluid can be drawn into the compressor at a lower cryogenic temperature, thereby improving the compression efficiency of the compressor.

[0046] In a third aspect, the cryogenic compression equipment is the cryogenic compression equipment of the first or second aspect, further comprising a discharge-side pipe connected to the discharge port of the compressor, and the heating device is provided in the discharge-side pipe.

[0047] According to the above aspect, the heating device is provided on the discharge side pipe, which makes it possible to easily install the heating device.

[0048] In a fourth aspect, in the cryogenic compression equipment of the third aspect, the discharge side piping includes a piping section connected to the discharge port, and a covering member having thermal insulation properties that covers the piping section.

[0049] According to the above aspect, the discharge-side pipe includes the pipe portion and the covering member, which makes it possible to reduce costs related to low-temperature countermeasures.

[0050] In a fifth aspect, the cryogenic compression equipment of the third or fourth aspect further includes a downstream pipe connected downstream of the discharge pipe, and the heating device heats the temperature of the compressed fluid to a temperature within the operating temperature limit range of the downstream pipe, which includes room temperature.

[0051] According to the above aspect, the heating device heats the temperature of the compressed fluid to within the operating temperature range of the downstream piping, including room temperature. This allows for mitigating the need for low-temperature countermeasures, thereby further reducing the cost of cryogenic compression equipment.

[0052] In a sixth aspect, in the cryogenic compression facility of the fifth aspect, the downstream piping is made of carbon steel.

[0053] According to the above aspect, the downstream piping is made of carbon steel, which reduces the cost of the downstream piping, thereby further reducing the cost of the cryogenic compression equipment.

[0054] In a seventh aspect of the present invention, in the cryogenic compression equipment of any one of the first to sixth aspects, the heating device is a heat exchanger through which a heat medium flows, and heat is exchanged between the heat medium and the compressed fluid.

[0055] According to the above aspect, the heating device is a heat exchanger through which a heat medium flows, and heat is exchanged between the heat medium and the compressed fluid. Therefore, the heating device can cause the cold in the compressed fluid to be absorbed by the heat medium. This allows the cold to be reused via the heat medium.

[0056] A boil-off gas liquefaction system in an eighth aspect comprises a cryogenic compression facility of any one of the first to seventh aspects and a liquefier that liquefies compressed fluid discharged from the cryogenic compression facility, and the cryogenic compression facility sucks in boil-off gas, which is a cryogenic fluid generated by vaporization of a cryogenic liquid in a liquid tank that stores the cryogenic liquid.

[0057] According to the above aspect, the cryogenic compression equipment sucks in boil-off gas, which is a cryogenic fluid generated by vaporizing a cryogenic liquid in the liquid tank. The cryogenic compression equipment then compresses and discharges the boil-off gas, and the liquefier liquefies the compressed boil-off gas discharged from the cryogenic compression equipment. Therefore, a boil-off gas liquefaction system capable of reusing the boil-off gas can be constructed. Furthermore, as described above, an increase in the cost of the cryogenic compression equipment can be suppressed, so a cost-saving boil-off gas liquefaction system can be constructed.

[0058] From the above description, many modifications and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention.

[0059] REFERENCE SIGNS LIST 1 Boil-off gas liquefaction system 3 Liquefied hydrogen tank (liquid tank) 11 Compression equipment 13 Liquefier 21 Compressor 21a Inlet 21b Compression section 21c Discharge port 22 Heating device 23 Inlet side piping 24 Discharge side piping 24a Piping section 24b Covering member 25 Downstream side piping

Claims

1. A cryogenic compression facility comprising: a compressor including an intake port for drawing in a cryogenic fluid, a compression section for compressing the drawn in cryogenic fluid, and a discharge port for discharging the compressed fluid; and a heating device for heating the compressed fluid discharged from the discharge port.

2. The cryogenic compression facility according to claim 1, further comprising a suction-side pipe connected to the suction port of the compressor, the suction-side pipe being a vacuum-insulated double pipe.

3. The cryogenic compression facility according to claim 1, further comprising a discharge-side pipe connected to the discharge port of the compressor, wherein the heating device is provided in the discharge-side pipe.

4. A cryogenic compression facility as described in claim 3, wherein the discharge side piping includes a piping section connected to the discharge port and a covering member having insulating properties that covers the piping section.

5. A cryogenic compression facility as described in claim 3, further comprising a downstream pipe connected downstream of the discharge pipe, wherein the heating device heats the temperature of the compressed fluid to within the operating temperature limit range of the downstream pipe, which includes room temperature.

6. The cryogenic compression facility of claim 5, wherein the downstream piping is made of carbon steel.

7. The cryogenic compression facility according to claim 1, wherein the heating device is a heat exchanger through which a heat medium flows, and heat is exchanged between the heat medium and the compressed fluid.

8. A boil-off gas liquefaction system comprising: a cryogenic compression facility as set forth in claim 1; and a liquefier that liquefies compressed fluid discharged from the cryogenic compression facility, wherein the cryogenic compression facility sucks in boil-off gas, which is a cryogenic fluid generated when a cryogenic liquid vaporizes in a liquid tank that stores the cryogenic liquid.

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