Cooling device and cooling method

Abstract

To provide a cooling device and a cooling method that can reduce compression power for cooling raw material gas.SOLUTION: A cooling device comprises: a gas introduction part for receiving compressed raw material gas from a raw material gas supply source; a first expansion part for expanding a first portion of the raw material gas; a first heat exchange part for cooling a second portion of the raw material gas by the first portion whose temperature has been decreased by expansion; and a compression part for compressing the first portion whose temperature has been increased by heat exchange, and merging it into the raw material gas received from the gas introduction part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a cooling device and a cooling method.

Background Art

[0002] Techniques for cooling raw material gas are known. For example, Patent Document 1 discloses an apparatus for liquefying hydrogen gas by cooling hydrogen gas obtained by electrolyzing water stored in a water tank with an electrolyzer through heat exchange with a refrigerant circulating in a refrigeration cycle. The refrigeration cycle uses helium gas as a refrigerant gas and consists of a Brayton cycle including a compressor for compressing helium gas, a radiator for removing heat during compression, and an expansion turbine for adiabatically expanding high-pressure helium gas to generate helium gas at a temperature below the hydrogen liquefaction temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a cooling device such as that of Patent Document 1, there is a problem that the compression power of the compressor is large as the power for cooling the raw material gas.

[0005] An object of the present disclosure is to provide a cooling device and a cooling method capable of reducing the compression power for cooling the raw material gas.

Means for Solving the Problems

[0006] To achieve the above object, the cooling device of the present disclosure includes a gas introduction part that receives compressed source gas from a source gas supply source, a first expansion part that expands a first portion of the source gas, a first heat exchange part that cools a second portion of the source gas with the first portion whose temperature has been lowered by expansion, and a compression part that compresses the first portion whose temperature has risen by heat exchange and merges it into the source gas received from the gas introduction part.

[0007] Further, the cooling method of the present disclosure includes a step of receiving compressed source gas from a source gas supply source, a step of expanding a first portion of the source gas, a step of cooling a second portion of the source gas with the first portion whose temperature has been lowered by expansion, and a step of compressing the first portion whose temperature has risen and merging it into the source gas received from the source gas supply source.

[0008] Also, the cooling device of the present disclosure includes a gas introduction part that receives compressed source gas from a source gas supply source, a refrigeration cycle that has a compression part and an expansion part and circulates a refrigerant, a heat exchange part that cools the source gas with the refrigerant of the refrigeration cycle, and an auxiliary expansion part that assists the compression power of the compression part of the refrigeration cycle by expanding the source gas.

[0009] Further, the cooling method of the present disclosure includes a step of receiving compressed source gas from a source gas supply source, a step of cooling the source gas with the refrigerant of a refrigeration cycle that has a compression part and an expansion part and circulates a refrigerant, and a step of assisting the compression power of the compression part of the refrigeration cycle by expanding the source gas.

[0010] Further, the cooling device of the present disclosure includes a refrigeration cycle having a gas introduction part that receives raw material gas from a raw material gas supply source, a compression part that compresses the raw material gas, and an expansion part that expands the compressed raw material gas, and a booster valve that compresses a second part of the raw material gas by the expansion energy of the first part of the raw material gas and sends the expanded first part to the compression part, and a heat exchange part that cools the second part compressed by the booster valve with the raw material gas flowing through the refrigeration cycle.

[0011] Further, the cooling method of the present disclosure includes a step of receiving raw material gas from a raw material gas supply source, a step of compressing a second part of the raw material gas by the expansion energy of the first part of the raw material gas by a booster valve, and a step of cooling the second part compressed by the booster valve with the raw material gas flowing through a refrigeration cycle having a compression part that compresses the raw material gas and an expansion part that expands the compressed raw material gas, and a step of compressing the first part expanded by the booster valve by the compression part.

Advantages of the Invention

[0012] According to the present disclosure, it is possible to provide a cooling device and a cooling method capable of reducing the compression power for cooling the raw material gas.

Brief Description of the Drawings

[0013]

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Embodiments for Carrying Out the Invention

[0014] Hereinafter, with reference to the drawings, preferred embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited by this embodiment, and when there are multiple embodiments, those configured by combining each embodiment are also included. In addition, the constituent elements in the embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within the so-called equivalent range.

[0015] [First Embodiment] FIG. 1 is a schematic configuration diagram showing a cooling device 1 according to the first embodiment. In the first embodiment, the cooling device 1 is configured as a liquefaction device that cools and liquefies the raw material gas 90. Further, the cooling device 1 of the first embodiment shown in FIG. 1 is configured based on a Claude cycle.

[0016] The cooling device 1 liquefies the raw material gas 90 by cooling the raw material gas 90 to the liquefaction temperature. The raw material gas 90 becomes a liquefied gas when liquefied. The raw material gas 90 is, for example, a low-boiling-point gas. Examples of the low-boiling-point gas include, but are not particularly limited to, hydrogen gas, oxygen gas, nitrogen gas, etc. Hydrogen gas becomes liquid hydrogen at a liquefaction temperature of about -253°C under standard atmospheric pressure. Oxygen gas becomes liquid oxygen at a liquefaction temperature of about -183°C under standard atmospheric pressure. Nitrogen gas becomes liquid nitrogen at a liquefaction temperature of about -196°C under standard atmospheric pressure. The cooling device 1 does not necessarily have to liquefy the raw material gas 90.

[0017] (Cooling Device) The cooling device 1 includes a gas introduction part 2, an expansion part, a heat exchange part, and a compression part 8. The expansion part includes a first expansion part 3 and a second expansion part 4. The heat exchange part includes a first heat exchange part 5, a second heat exchange part 6, and a third heat exchange part 7. The cooling device 1 configured as a liquefaction device includes an expansion valve 21 and a liquid tank 22 for storing the liquefied gas obtained by liquefying the raw material gas 90. Further, in the example of FIG. 1, the cooling device 1 includes a refrigeration cycle 30 that cools the raw material gas 90 with a refrigerant 35.

[0018] The gas introduction part 2 receives the compressed raw material gas 90 from the raw material gas supply source 23. That is, in the first embodiment, the gas introduction part 2 receives the high-pressure raw material gas that has been pre-compressed. The pressure P1 of the raw material gas 90 in the gas introduction part 2 is greater than the atmospheric pressure. The pressure P1 is, for example, 0.5 MPa or more, preferably 1 MPa or more. The pressure P1 is, for example, about 3 MPa.

[0019] The raw material gas supply source 23 that supplies the compressed raw material gas 90 can use, for example, a high-pressure gas tank or a pressure accumulator such as an accumulator. Further, the cooling device 1 can include a raw material gas generation device 50 (see FIG. 2) described later as the raw material gas supply source 23.

[0020] The gas introduction part 2 is connected to the second expansion part 4 through the flow path 11. The flow path 11 passes through the third heat exchange part 7 and the second heat exchange part 6 in this order. The second expansion part 4 is connected to the first expansion part 3 and the expansion valve 21 respectively by the branched flow path 12. That is, the flow path 12 branches into two, the flow path 13A and the flow path 13B. The flow path 12 divides the raw material gas 90 into two, the first part 91 and the second part 92, by the branching. The flow path 13A is connected to the first expansion part 3. The flow path 13A supplies the first part 91 of the raw material gas 90 to the first expansion part 3. The flow path 13B is connected to the expansion valve 21. The flow path 13B passes through the second heat exchange part 6 and the first heat exchange part 5 in this order. The flow path 13B supplies the second part 92 of the raw material gas 90 to the expansion valve 21 after passing through the second heat exchange part 6 and the first heat exchange part 5.

[0021] The first expansion part 3 is connected to a return flow path 16 that connects from the liquid tank 22 to the compression part 8 via the flow path 14. The expansion valve 21 is connected to the liquid tank 22 by the flow path 15. The return flow path 16 connects the liquid tank 22 and the compression part 8. The return flow path 16 passes through the first heat exchange part 5 and the third heat exchange part 7 in this order. The compression part 8 is connected to the flow path 11 by the flow path 17. The compression part 8 is connected between the gas introduction part 2 and the third heat exchange part 7 in the flow path 11.

[0022] The refrigeration cycle 30 includes a circulation flow path 33 that connects the compression part 31 and the expansion part 32. The circulation flow path 33 circulates the refrigerant 35 between the compression part 31 and the expansion part 32. The circulation flow path 33 passes through the third heat exchange part 7.

[0023] The first expansion part 3 and the second expansion part 4 each include an expansion turbine. The first expansion part 3 and the second expansion part 4 lower the temperature by expanding the inflowing raw material gas 90.

[0024] The first expansion section 3 expands the first portion 91 of the raw material gas 90. That is, the first expansion section 3 receives and expands the first portion 91 among the raw material gas 90 that is divided into the first portion 91 and the second portion 92 by the branched flow path 12. Since the second portion 92 is not supplied to the first expansion section 3, the first expansion section 3 does not expand the second portion 92. The first expansion section 3 expands the first portion 91 and supplies the first portion 91 whose temperature has decreased due to the expansion from the flow path 14 to the return flow path 16.

[0025] The second expansion section 4 is provided upstream of the first expansion section 3. The second expansion section 4 receives and expands the raw material gas 90 before it is divided by the flow path 12. The second expansion section 4 expands the raw material gas 90 received from the flow path 11 and supplies the raw material gas 90 whose temperature has decreased due to the expansion to the flow path 12.

[0026] Thus, the cooling device 1 expands and reduces the temperature of the high-pressure raw material gas 90 received from the gas introduction section 2 in two stages by the first expansion section 3 and the second expansion section 4. The second expansion section 4 expands the raw material gas 90 to a pressure P2 lower than the pressure P1. The first expansion section 3 further expands the first portion 91 of the raw material gas 90 after the expansion by the second expansion section 4. The second expansion section 4 expands the first portion 91 to a pressure P3 lower than the pressure P2.

[0027] The first heat exchange section 5, the second heat exchange section 6, and the third heat exchange section 7 each include a heat exchanger that performs heat exchange between a plurality of fluids. The first heat exchange section 5, the second heat exchange section 6, and the third heat exchange section 7 each have one or more high-temperature side flow paths through which a high-temperature side fluid flows and one or more low-temperature side flow paths through which a low-temperature side fluid flows. The first heat exchange section 5, the second heat exchange section 6, and the third heat exchange section 7 cool the fluid flowing through the high-temperature side flow path by transferring the heat of the fluid flowing through the high-temperature side flow path to the fluid flowing through the low-temperature side flow path. The first heat exchange section 5 and the second heat exchange section 6 each have an ortho-para conversion section 40. The ortho-para conversion section 40 includes a catalyst for promoting the ortho-para conversion of the raw material gas 90 (hydrogen). The catalyst of the ortho-para conversion section 40 is provided in a passage portion through which the raw material gas 90 flows so as to contact the raw material gas 90.

[0028] The first heat exchange section 5 is disposed across the flow path 13B and the return flow path 16. In the first heat exchange section 5, the flow path 13B is the high-temperature side flow path and the return flow path 16 is the low-temperature side flow path. The first heat exchange section 5 performs heat exchange between the second portion 92 of the raw material gas 90 flowing through the flow path 13B and the raw material gas 90 flowing through the return flow path 16. The first heat exchange section 5 cools the second portion 92 of the raw material gas 90 after expansion by the second expansion section 4 with the first portion 91 after expansion by the second expansion section 4 and the first expansion section 3. That is, the second portion 92 of the raw material gas 90 after expansion by the second expansion section 4 flows through the flow path 13B. The low-temperature first portion 91 of the raw material gas 90 after expansion by the first expansion section 3 and the low-temperature raw material gas 90 from the liquid tank 22 flow through the return flow path 16. Thereby, the first heat exchange section 5 cools the second portion 92 of the raw material gas 90 with the return gas including the first portion 91.

[0029] The expansion valve 21 expands the second portion 92 cooled by the first heat exchanger 5 to liquefy at least a part of the second portion 92. The expansion valve 21 is composed of, for example, a Joule-Thomson valve. The expansion valve 21 cools by expanding the second portion 92 of the raw material gas 90. At least a part of the second portion 92 that has passed through the expansion valve 21 liquefies. Therefore, the fluid flowing through the flow path 15 becomes a gas-liquid mixed phase state of the vapor-phase raw material gas 90 (second portion 92) and the liquid-phase liquefied gas. The raw material gas 90 and the liquefied gas flow into the liquid tank 22 and separate inside the liquid tank 22. The vapor-phase raw material gas 90 that has flowed into the liquid tank 22 and the raw material gas 90 generated (vaporized) inside the liquid tank 22 flow into the return flow path 16 due to the negative pressure of the compression section 8.

[0030] The second heat exchanger 6 is disposed across the flow path 11 and the flow path 13B. In the second heat exchanger 6, the flow path 11 is the high-temperature side flow path and the flow path 13B is the low-temperature side flow path. The second heat exchanger 6 performs heat exchange between the raw material gas 90 flowing through the flow path 11 and the second portion 92 flowing through the flow path 13B. That is, the raw material gas 90 before expansion by the second expansion section 4 flows through the flow path 11. The second portion 92 of the raw material gas 90 whose temperature has decreased due to expansion in the second expansion section 4 flows through the flow path 13B. Thereby, the second heat exchanger 6 cools the raw material gas 90 before expansion by the second expansion section 4 with the second portion 92 of the raw material gas 90 after expansion by the second expansion section 4.

[0031] Note that in the flow path 13B, the second heat exchanger 6 is disposed on the upstream side of the first heat exchanger 5, that is, at a position closer to the branching point. Therefore, the first heat exchanger 5 cools the second portion 92 that has passed through the second heat exchanger 6 with the first portion 91 expanded by the first expansion section 3.

[0032] The third heat exchanger 7 is disposed across the flow path 11, the return flow path 16, and the circulation flow path 33. The third heat exchanger 7 performs heat exchange between the raw material gas 90 flowing through the flow path 11, the raw material gas 90 flowing through the return flow path 16, and the refrigerant flowing through the circulation flow path 33. Thereby, the third heat exchanger 7 cools the raw material gas 90 with the refrigerant 35.

[0033] Note that the third heat exchanger 7 is passed through by both the high-pressure side portion 33A and the low-pressure side portion 33B of the circulation flow path 33. Therefore, the third heat exchanger 7 cools the high-temperature and high-pressure refrigerant flowing through the high-pressure side portion 33A with the low-temperature and low-pressure refrigerant flowing through the low-pressure side portion 33B in the refrigeration cycle 30. Accordingly, in the third heat exchanger 7, the flow path 11 and the high-pressure side portion 33A are high-temperature side flow paths, and the return flow path 16 and the low-pressure side portion 33B are low-temperature side flow paths. The raw material gas 90 received from the gas introduction portion 2 into the flow path 11 is cooled not only by the raw material gas 90 flowing through the return flow path 16 but also by the refrigerant 35 of the refrigeration cycle 30, enabling effective cooling. As a result, the capacity of the compression portion 8 can be reduced.

[0034] The compression portion 8 includes a compressor having a compression mechanism and a motor for driving the compression mechanism. The compression method of the compressor is not particularly limited. Examples of the compressor include a positive displacement type and a turbo type compressor. The compression portion 8 increases the pressure by compressing the introduced raw material gas 90. The compression portion 8 includes a cooling mechanism for removing the heat of the raw material gas 90 accompanying the compression. The cooling method of the cooling mechanism is not particularly limited, but for example, it is a water-cooled type.

[0035] The compression portion 8 receives the raw material gas 90 via the return flow path 16. The compression portion 8 compresses the raw material gas 90 received from the return flow path 16 and sends it out to the flow path 11 via the flow path 17. In the return flow path 16, a return gas including a first portion 91 that has merged from the first expansion portion 3 into the return flow path 16 via the flow path 14 and the raw material gas 90 of the liquid tank 22 flows. The return gas flowing through the return flow path 16 passes through the first heat exchanger 5 and the third heat exchanger 7 and then flows into the compression portion 8. The compression portion 8 compresses the return gas (the first portion 91 and the raw material gas 90 from the liquid tank 22) whose temperature has risen due to heat exchange and merges it with the raw material gas 90 received from the gas introduction portion 2.

[0036] The compression section 8 compresses the raw material gas 90 received from the return flow path 16 to the pressure P1 in the gas introduction section 2 and sends it out to the flow path 11. In the first embodiment, in the gas introduction section 2, the raw material gas 90 pre-compressed to the pressure P1 at which expansion by the second expansion section 4 and the first expansion section 3 is possible is introduced. The compression section 8 compresses the raw material gas 90 (return gas) at a pressure lower than the pressure of the raw material gas 90 received by the gas introduction section 2. That is, the compression section 8 compresses only the low-pressure raw material gas 90 (return gas) flowing through the return flow path 16 without compressing the raw material gas 90 received by the gas introduction section 2. For this reason, the capacity of the compression section 8 can be reduced as compared with the case of compressing the total amount of the raw material gas 90 received by the gas introduction section 2 and the raw material gas 90 flowing through the return flow path 16.

[0037] The compression section 31 and the expansion section 32 included in the refrigeration cycle 30 each have the same configuration as the compression section 8 and the expansion sections (the first expansion section 3, the second expansion section 4) on the raw material gas 90 side. The refrigeration cycle 30 compresses the refrigerant 35 by the compression section 31, cools it by the cooling mechanism included in the compression section 31 and the third heat exchange section 7 in the high-pressure side portion 33A, and then expands it by the expansion section 32 to generate a low-temperature and low-pressure refrigerant 35. The refrigeration cycle 30 supplies the low-temperature and low-pressure refrigerant to the third heat exchange section 7 in the low-pressure side portion 33B to cool the raw material gas 90 flowing through the flow path 11.

[0038] The refrigerant 35 used in the refrigeration cycle 30 is not particularly limited as long as it can cool the raw material gas 90 flowing through the flow path 11, and is, for example, nitrogen gas. The compression section 31 of the refrigeration cycle 30 compresses the refrigerant 35 to about 0.8 MPa, for example. The expansion section 32 expands the refrigerant 35 to about 0.1 MPa.

[0039] (Cooling method) Next, the cooling method according to the first embodiment will be described.

[0040] The cooling method according to the first embodiment includes a step of receiving the compressed raw material gas 90 from the raw material gas supply source 23. That is, the gas introduction section 2 receives the raw material gas 90 compressed to the pressure P1 from the raw material gas supply source 23. The gas introduction section 2 passes the received raw material gas 90 through the third heat exchange section 7 and the second heat exchange section 6 in the flow path 11 in order, and supplies it to the second expansion section 4. The pressure P1 is, for example, about 3 MPa.

[0041] The third heat exchange section 7 primarily cools the raw material gas 90 flowing through the flow path 11 from the gas introduction section 2 with the refrigerant of the refrigeration cycle 30 and the low-temperature and low-pressure raw material gas 90 flowing through the return flow path 16. The second heat exchange section 6 secondarily cools the raw material gas 90 in the flow path 11 that has been primarily cooled by the third heat exchange section 7 with the second portion 92 (the raw material gas after expansion by the second expansion section 4) of the raw material gas 90 flowing through the flow path 13B.

[0042] The second expansion section 4 expands the raw material gas 90 from the flow path 11 and supplies it to the flow path 12. The second expansion section 4 expands the received raw material gas 90 at the pressure P1 to a pressure P2 lower than the pressure P1. The raw material gas 90 from the second expansion section 4 is divided into two, a first portion 91 and a second portion 92, in the flow path 12. The first portion 91 of the raw material gas 90 flows into the first expansion section 3 through the flow path 13A. The second portion 92 of the raw material gas 90 passes through the second heat exchange section 6 and the first heat exchange section 5 in order in the flow path 13B and flows into the expansion valve 21.

[0043] The cooling method according to the first embodiment includes a step of expanding the first portion 91 of the raw material gas 90. That is, the first expansion section 3 expands the first portion 91 of the raw material gas 90 from the flow path 13A and supplies it to the return flow path 16 through the flow path 14. The first expansion section 3 expands the received first portion 91 of the raw material gas 90 at the pressure P2 to a pressure P3 lower than the pressure P2. The pressure P3 is, for example, about 0.1 MPa.

[0044] The cooling method according to the first embodiment includes a step of cooling the second portion 92 of the raw material gas 90 with the first portion 91 whose temperature has been lowered by expansion. That is, the first heat exchange section 5 cools the medium-temperature and medium-pressure second portion 92 of the raw material gas 90 flowing through the flow path 13B with the low-temperature and low-pressure first portion 91 (and the raw material gas 90 from the liquid tank 22) flowing through the return flow path 16.

[0045] The expansion valve 21 expands the second portion 92 of the raw material gas 90 at a low temperature and medium pressure (pressure P2) cooled by the first heat exchange section 5. The expansion valve 21 expands and cools the second portion 92 at pressure P2 to pressure P3, and liquefies at least a part of the second portion 92. As a result, liquefied gas is generated from the raw material gas 90 and flows into the liquid tank 22 through the flow path 17. The raw material gas 90 at a low temperature and low pressure (pressure P3) in the liquid tank 22 flows into the return flow path 16.

[0046] The return flow path 16 receives the first portion 91 from the first expansion section 3 and the raw material gas 90 from the liquid tank 22, passes them through the first heat exchange section 5 and the third heat exchange section 7 in sequence, uses them for cooling the raw material gas 90, and then sends them to the compression section 8.

[0047] The cooling method according to the first embodiment includes a step of compressing the temperature-risen first portion 91 and merging it with the raw material gas 90 received from the raw material gas supply source 23. That is, the compression section 8 receives the return gas at pressure P3 including the first portion 91 and the raw material gas 90 from the liquid tank 22 from the return flow path 16 and compresses it to pressure P1. After removing the heat generated by compression with a cooling mechanism, the compression section 8 merges the return gas compressed to pressure P1 from the flow path 17 into the raw material gas 90 in the flow path 11.

[0048] As described above, a part of the raw material gas 90 received by the gas introduction section 2 is liquefied and stored in the liquid tank 22. Among the raw material gas 90 received by the gas introduction section 2, the remaining portion that is not liquefied is sent from the return flow path 16 to the compression section 8, returned to the pressure P1 of the gas introduction section 2, and merged with the raw material gas 90 received by the gas introduction section 2. As a result, as the raw material gas 90 circulates through the flow paths of the cooling device 1, the raw material gas 90 is liquefied sequentially in parts.

[0049] (Raw material gas supply source) FIG. 2 is a diagram showing a configuration example of a raw material gas supply source 23 according to the first embodiment. In the example of FIG. 2, the cooling device 1 further includes a raw material gas generation device 50 that generates a raw material gas 90 from a raw material liquid 95 as the raw material gas supply source 23 and supplies the generated raw material gas 90 to the gas introduction section 2.

[0050] In the first embodiment, hydrogen gas is exemplified as the raw material gas 90. The raw material gas generation device 50 generates hydrogen gas, which is the raw material gas 90, using water as the raw material liquid 95. The raw material gas generation device 50 is a water electrolysis device that generates hydrogen gas and oxygen gas by electrolyzing water.

[0051] The raw material gas generation device 50 includes a raw material liquid tank 51, a pressurizing section 52, a raw material gas generation section 53, and a gas delivery path 54. The raw material gas generation section 53 includes a gas-liquid separator 56 and an electrolysis device 57.

[0052] The raw material liquid tank 51 stores the raw material liquid 95. The raw material liquid tank 51 stores water as the raw material liquid 95.

[0053] The pressurizing section 52 includes a liquid pump. The pressurizing section 52 is connected to the raw material liquid tank 51 and the gas-liquid separator 56 via a pipe 55. The pressurizing section 52 pressurizes and supplies the raw material liquid 95 stored in the raw material liquid tank 51 to the raw material gas generation section 53. The pressurizing section 52 compresses the raw material gas 90 by pressurizing and supplying the raw material liquid 95 to the raw material gas generation section 53. The pressurizing section 52 includes a first pump 52A and a second pump 52B. The first pump 52A pressurizes and supplies the raw material liquid 95 stored in the raw material liquid tank 51 to the first separator 56A of the gas-liquid separator 56. The second pump 52B pressurizes and supplies the raw material liquid 95 stored in the raw material liquid tank 51 to the second separator 56B of the gas-liquid separator 56.

[0054] The gas-liquid separator 56 separates the raw material gas 90 generated from the raw material liquid 95 and the raw material liquid 95. The gas-liquid separator 56 includes a first separator 56A and a second separator 56B. The first separator 56A separates the raw material gas 90 (hydrogen gas) generated from the raw material liquid 95 from the raw material liquid 95. The second separator 56B separates the oxygen gas as the by-product gas 96 generated from the raw material liquid 95 from the raw material liquid 95. The raw material gas 90 (hydrogen gas) in the first separator 56A is compressed by the raw material liquid 95 pressurized and supplied from the first pump 52A. The by-product gas 96 (oxygen gas) in the second separator 56B is compressed by the raw material liquid 95 pressurized and supplied from the second pump 52B.

[0055] The electrolysis device 57 electrolyzes the raw material liquid 95 to generate the raw material gas 90. The electrolysis device 57 electrolyzes water as the raw material liquid 95 to generate hydrogen gas as the raw material gas 90 and oxygen gas as the by-product gas 96.

[0056] The gas delivery path 54 is connected to the gas-liquid separator 56 and the gas introduction part 2, and sends out the raw material gas 90 generated in the gas-liquid separator 56 to the gas introduction part 2. The gas delivery path 54 includes a first line 54A and a second line 54B. The first line 54A connects the first separator 56A and the gas introduction part 2. The first line 54A allows the raw material gas 90 to flow through. The second line 54B connects the second separator 56B and the liquefaction treatment part 70. The second line 54B allows the by-product gas 96 to flow through.

[0057] Back pressure valves 58A and 58B and pressure regulating valves 59A and 59B are provided in the first line 54A and the second line 54B. The back pressure valves 58A and 58B are arranged on the upstream side (the gas-liquid separator 56 side) of the pressure regulating valves 59A and 59B. The back pressure valves 58A and 58B maintain the pressure of the gas (raw material gas 90, by-product gas 96) from the gas-liquid separator 56 constant. The pressure regulating valves 59A and 59B adjust the pressure of the gas (raw material gas 90, by-product gas 96) led out from the first line 54A and the second line 54B to a set value.

[0058] In the embodiment, the gas (raw material gas 90, by-product gas 96) in the gas-liquid separator 56 is compressed by the pressurization supply of the raw material liquid 95 by the pressurization unit 52. The back pressure valves 58A and 58B adjust the gas pressure to the set pressure by releasing the pressure when the gas pressure in the first separator 56A and the second separator 56B exceeds the set value. The pressure regulating valves 59A and 59B adjust the gas passing through the back pressure valves 58A and 58B to a desired supply pressure. Therefore, in the embodiment, the first pump 52A of the pressurization unit 52 pressurizes the raw material gas 90 to the set pressure Ps0 of the back pressure valve 58A. The set pressure Ps0 is higher than the pressure P1 supplied to the gas introduction unit 2. The set pressure Ps0 is not particularly limited, but is, for example, about 30 MPa. The pressure regulating valve 59A adjusts the pressure of the raw material gas 90 to the pressure P1 supplied to the gas introduction unit 2. Thereby, the raw material gas generation device 50 introduces the raw material gas 90 adjusted to the pressure P1 into the gas introduction unit 2.

[0059] In the example of FIG. 2, the cooling device 1 can cool and liquefy the by-product gas 96 in the same manner as the raw material gas 90 by the liquefaction processing unit 70. The raw material gas generation device 50 introduces the by-product gas 96 compressed to the pressure Ps1 into the liquefaction processing unit 70 of the by-product gas 96. The second pump 52B of the pressurization unit 52 pressurizes the by-product gas 96 to the set pressure Ps1 of the back pressure valve 58B. The pressure regulating valve 59B reduces the pressure of the by-product gas 96 to the pressure supplied to the liquefaction processing unit 70. The supply pressure of the by-product gas 96 is, for example, about 0.1 MPa.

[0060] (Liquefaction processing unit) FIG. 3 is a schematic configuration diagram showing the liquefaction processing unit 70 of the by-product gas 96. The liquefaction processing unit 70 includes a by-product gas flow path 71, a refrigeration cycle 72, heat exchange units 73 and 74, and a liquid tank 75 for the by-product gas 96. In this example, the by-product gas 96 is oxygen gas as described above.

[0061] The by-product gas flow path 71 receives the by-product gas 96 from the raw material gas generation device 50 and sends it to the liquid tank 75.

[0062] The refrigeration cycle 72 includes a compression section 76, an expansion section 77, and a refrigerant circulation flow path 78. The refrigeration cycle 72 has the same configuration as the refrigeration cycle 30 shown in FIG. 1. The refrigerant is, for example, nitrogen gas. The refrigeration cycle 72 compresses the refrigerant by the compression section 76, cools it by a cooling mechanism provided in the compression section 76 and a heat exchange section 73 in the high-pressure side portion 78A, and then expands it by the expansion section 77 to generate a low-temperature and low-pressure refrigerant. The compression section 76 compresses the refrigerant to about 0.8 MPa, and the expansion section 77 expands the refrigerant to about 0.1 MPa. The refrigeration cycle 72 supplies the low-temperature and low-pressure refrigerant to the heat exchange section 74 and the heat exchange section 73 in the low-pressure side portion 78B in sequence.

[0063] The heat exchange section 73 primarily cools the by-product gas 96 flowing through the by-product gas flow path 71 with the refrigerant of the refrigeration cycle 30. The heat exchange section 74 secondarily cools the by-product gas 96 in the by-product gas flow path 71 that has been primarily cooled by the heat exchange section 73 with the refrigerant of the refrigeration cycle 30. The heat exchange section 74 liquefies at least a part of the by-product gas 96 by the secondary cooling. Thereby, the liquefaction processing section 70 generates a liquefied gas (liquid oxygen) of the by-product gas 96 and sends it to the liquid tank 75.

[0064] With such a configuration, in the first embodiment, the cooling device 1 generates hydrogen gas at a high pressure (pressure P1) and oxygen gas generated by electrolysis using water as the raw material liquid 95. The cooling device 1 cools the hydrogen gas at a high pressure (pressure P1) as the raw material gas 90 to generate liquid hydrogen. The cooling device 1 cools the oxygen gas as the by-product gas 96 to generate liquid oxygen.

[0065] [First Modification Example of the First Embodiment] FIG. 4 is a schematic configuration diagram showing a cooling device 1A according to a first modification of the first embodiment. In the cooling device 1A, compared with the cooling device 1 of the first embodiment shown in FIG. 1, a refrigeration cycle 30 and a third heat exchange section 7 are not provided. Further, in the cooling device 1 of FIG. 1, an example in which a two-stage expansion section including a first expansion section 3 and a second expansion section 4 is provided is shown, but in the cooling device 1A of FIG. 4, a one-stage expansion in which only the first expansion section 3 is provided is performed. Therefore, the cooling device 1A is not provided with the second expansion section 4 and the second heat exchange section 6.

[0066] The flow path 11 passes through the heat exchange section 81 and the heat exchange section 82 in order from the gas introduction section 2, and branches into a branch path 83A and a branch path 83B. The branch path 83A is connected to the first expansion section 3. The branch path 83B passes through the first heat exchange section 5 and is connected to the expansion valve 21. The heat exchange section 81, the heat exchange section 82, and the first heat exchange section 5 each have an ortho-para conversion section 40.

[0067] The discharge port of the first expansion section 3 is connected to the return flow path 16 from the liquid tank 22 via the flow path 14. The expansion valve 21 is connected to the liquid tank 22 via the flow path 15. After the return flow path 16 merges with the flow path 14, it passes through the first heat exchange section 5, the heat exchange section 82, and the heat exchange section 81 in order and is connected to the compression section 8. The discharge port of the compression section 8 is connected to a position between the gas introduction section 2 of the flow path 11 and the heat exchange section 81 via the flow path 17.

[0068] Thereby, the first expansion section 3 expands the first portion 91 of the raw material gas 90 supplied from the branch path 83A. The first heat exchange section 5 cools the second portion 92 of the raw material gas 90 supplied from the branch path 83B with the return gas flowing through the return flow path 16. The return gas flowing through the return flow path 16 includes the first portion 91 whose temperature has decreased due to the expansion by the first expansion section 3 and the raw material gas 90 from the liquid tank 22. The compression section 8 compresses the return gas including the first portion 91 whose temperature has risen due to heat exchange and merges it with the raw material gas 90 received from the gas introduction section 2.

[0069] [Second Modification of the First Embodiment] FIG. 5 is a schematic configuration diagram showing a cooling device 1B according to a second modification of the first embodiment. In the cooling device 1B, instead of the heat exchange section 81 of the cooling device 1A shown in FIG. 4, a refrigeration cycle 30 and a third heat exchange section 7 are provided. The third heat exchange section 7 straddles a flow path 11 and a return flow path 16 between the gas introduction section 2 and the heat exchange section 82. The third heat exchange section 7 cools the source gas 90 flowing through the flow path 11 with the refrigerant 35 of the refrigeration cycle 30. Since the cooling device 1B can effectively reduce the temperature of the source gas 90 by pre-cooling using the refrigeration cycle 30, the compression power in the compression section 8 can be reduced compared to the cooling device 1A shown in FIG. 4.

[0070] [Second Embodiment] FIG. 6 is a schematic configuration diagram showing a cooling device 101 according to the second embodiment. In the second embodiment, similar to the first embodiment, the cooling device 101 is configured as a liquefaction device that cools and liquefies the source gas 90, but the method for reducing the prime mover power is different.

[0071] The cooling device 101 according to the second embodiment includes a gas introduction section 102, a refrigeration cycle 103, a heat exchange section 104, and an auxiliary expansion section 105. Further, the cooling device 101 includes a cooling section 106 using a second refrigerant 192. The heat exchange section 104 includes a heat exchanger 107, a heat exchanger 108, and a heat exchanger 109.

[0072] The gas introduction section 102 receives the compressed source gas 90 from the source gas supply source 23. The source gas 90 is, for example, a low-boiling point gas. The low-boiling point gas is, for example, hydrogen gas. The pressure of the source gas 90 is pressure P11. The pressure P11 is greater than atmospheric pressure, for example, 0.5 MPa or more, preferably 1 MPa or more. The pressure P11 is, for example, about 30 MPa. The gas introduction section 102 sends the source gas 90 into the flow path 111.

[0073] The flow path 111 passes through the heat exchanger 107, the heat exchanger 108, and the heat exchanger 109 in order from the gas introduction section 102 and is connected to the auxiliary expansion section 105.

[0074] The refrigeration cycle 103 is composed of a gas refrigeration cycle using the same low-boiling point gas (hydrogen) as the raw material gas 90 as the refrigerant 191. The refrigeration cycle 103 includes a compression section 121, a cooling mechanism 122, an expansion section 123, and a circulation flow path 124 connecting these. The expansion section 123 includes an expansion valve 125 and an expansion turbine 126. Further, the circulation flow path 124 passes through the heat exchanger 107, the heat exchanger 108, and the heat exchanger 109. The refrigeration cycle 103 compresses the refrigerant 191 by the compression section 121 and removes the heat of the refrigerant 191 whose temperature has risen due to compression by the cooling mechanism 122. The cooling mechanism 122 is, for example, water-cooled. The refrigeration cycle 103 liquefies the refrigerant 191 by expanding the low-temperature and high-pressure gaseous refrigerant 191 (refrigerant hydrogen gas) by the expansion turbine 126 and the expansion valve 125, respectively. The refrigeration cycle 103 cools the raw material gas 90 (raw material hydrogen gas) by heat-exchanging the liquid-phase refrigerant 191 (refrigerant liquid hydrogen) with the raw material gas 90 in the heat exchanger 107 and the heat exchanger 109.

[0075] The cooling section 106 includes a storage tank 131 for storing the liquid-phase second refrigerant 192, a refrigerant supply path 132 for supplying the liquid-phase second refrigerant 192 to the storage tank 131, and a refrigerant discharge path 133 for discharging the gaseous second refrigerant 192 generated in the storage tank 131. The refrigerant discharge path 133 passes through the heat exchanger 107. The second refrigerant 192 is, for example, nitrogen.

[0076] The heat exchange section 104 cools the raw material gas 90 with the refrigerant 191 of the refrigeration cycle 103. Further, the heat exchange section 104 cools the raw material gas 90 with the second refrigerant 192 of the cooling section 106. The heat exchange section 104 cools the raw material gas 90 in three stages by the heat exchanger 107, the heat exchanger 108, and the heat exchanger 109.

[0077] The heat exchanger 107 cools the raw material gas 90 by heat exchange between the raw material gas 90 (raw material hydrogen gas), the refrigerant 191 (refrigerant hydrogen) of the refrigeration cycle 103, and the gaseous second refrigerant 192 (refrigerant nitrogen gas) of the cooling section 106.

[0078] The heat exchanger 108 is provided inside the storage tank 131 of the cooling unit 106 and is immersed in the liquid-phase second refrigerant 192. A catalyst section 134 for promoting the ortho-para conversion of the raw material hydrogen is provided in the passage portion through which the raw material gas 90 of the heat exchanger 108 flows. The heat exchanger 108 cools the raw material gas 90 (raw material hydrogen gas) and the refrigerant 191 (refrigerant hydrogen) of the refrigeration cycle 103 by the liquid-phase second refrigerant 192 in the storage tank 131. Inside the storage tank 131, the second refrigerant 192 vaporizes due to the heat received from the heat exchanger 108 and is discharged from the refrigerant discharge passage 133. The gaseous second refrigerant 192 flowing through the refrigerant discharge passage 133 is used for heat exchange in the heat exchanger 107 in the previous stage.

[0079] The heat exchanger 109 cools the raw material gas 90 by heat exchange between the raw material gas 90 (raw material hydrogen gas) and the refrigerant 191 of the refrigeration cycle 103. A catalyst section 134 for promoting the ortho-para conversion of the raw material hydrogen is provided in the passage portion through which the raw material gas 90 of the heat exchanger 109 flows.

[0080] The auxiliary expansion section 105 receives the raw material gas 90 that has passed through the heat exchange section 104 and been cooled via the flow path 111. In the second embodiment, the raw material gas 90 is introduced into the gas introduction section 102 in a state compressed to the pressure P11, cooled in the heat exchange section 104, and then supplied to the auxiliary expansion section 105. The auxiliary expansion section 105 expands the raw material gas 90 at the pressure P11. The auxiliary expansion section 105 assists the compression power of the compression section 121 of the refrigeration cycle 103 by expanding the raw material gas 90. Further, in the cooling device 101 configured as a liquefaction device, the auxiliary expansion section 105 assists the compression power of the compression section 121 by expanding the raw material gas 90 that has passed through the heat exchange section 104 from the gas introduction section 102 and been cooled, and liquefies at least a part of the raw material gas 90 by lowering the temperature of the raw material gas 90. The auxiliary expansion section 105 liquefies, for example, all of the raw material gas 90 introduced from the flow path 111.

[0081] Here, the compression part 121 of the refrigeration cycle 103 includes a compression turbine 127 that compresses the refrigerant 191 by rotation, and a drive part 128 that rotationally drives the compression turbine 127. The drive part 128 is, for example, an electric motor and is connected to the rotation shaft 129 of the compression turbine 127. The compression part 121 is a turbo compressor that compresses the refrigerant 191 when the drive part 128 rotates the compression turbine 127.

[0082] The auxiliary expansion part 105 includes an expansion turbine 113 connected to the compression turbine 127. The expansion turbine 113 is connected to the rotation shaft 129 of the compression turbine 127 and rotates integrally with the compression turbine 127. The auxiliary expansion part 105 expands the received raw material gas 90 at pressure P11 to a pressure P12 lower than the pressure P11 and rotationally drives the expansion turbine 113. The compression power for rotationally driving the compression turbine 127 is reduced by the amount of rotational power applied to the expansion turbine 113. The auxiliary expansion part 105 is connected to the discharge path 112. The liquefied gas (liquid hydrogen) expanded and liquefied to the pressure P12 is sent to the discharge path 112. The pressure P12 is, for example, about 0.1 MPa. In this case, the auxiliary expansion part 105 receives the raw material gas 90 at a pressure of 30 MPa and a temperature of -250°C and generates liquid hydrogen at a pressure of 0.1 MPa and a temperature of -253°C by expansion. The discharge path 112 supplies liquid hydrogen to, for example, a liquid tank or equipment that uses liquefied gas.

[0083] Note that the cooling device 101 according to the second embodiment may further include a raw material gas generation device 50 that generates the raw material gas 90 from the raw material liquid 95 and supplies the generated raw material gas 90 to the gas introduction part 102 as the raw material gas supply source 23. That is, as shown in FIG. 2, a raw material gas generation device 50 having a raw material gas generation part 53 and a pressurization part 52 that compresses the raw material gas 90 by pressurizing and supplying the raw material liquid 95 to the raw material gas generation part 53 may be connected to the gas introduction part 102 as the raw material gas supply source 23.

[0084] (Cooling method) Next, the cooling method according to the second embodiment will be described.

[0085] The cooling method according to the second embodiment includes a step of receiving the compressed raw material gas 90 from the raw material gas supply source 23. That is, the gas introduction part 102 receives the raw material gas 90 compressed to the pressure P11 from the raw material gas supply source 23. The gas introduction part 102 supplies the received raw material gas 90 to the auxiliary expansion part 105 by passing it through the heat exchangers 107, 108, and 109 in order in the flow path 111.

[0086] The cooling method according to the second embodiment includes a step of cooling the raw material gas 90 with the refrigerant 191 of the refrigeration cycle 103 that has the compression part 121 and the expansion part 123 and circulates the refrigerant 191. That is, the refrigeration cycle 103 passes the high-pressure gas-phase refrigerant 191 compressed in the compression part 121 and heat-removed in the cooling mechanism 122 through the heat exchangers 107, 108, and 109 in order. The expansion part 123 (expansion turbine 126 and expansion valve 125) liquefies the refrigerant 191 by expanding the low-temperature and high-pressure refrigerant hydrogen gas. The refrigeration cycle 103 cools the raw material gas 90 by heat-exchanging the liquid-phase refrigerant 191 (refrigerant liquid hydrogen) with the raw material gas 90 in the heat exchangers 107 and 109.

[0087] The heat exchanger 107 cools the raw material gas 90 in the flow path 111 and the gas-phase refrigerant 191 (refrigerant hydrogen gas) in the circulation flow path 124 with the gas-phase second refrigerant 192 (refrigerant nitrogen gas) sent from the cooling part 106 to the refrigerant discharge path 133 and the liquid-phase refrigerant 191 (refrigerant liquid hydrogen) of the refrigeration cycle 103.

[0088] The heat exchanger 108 cools the raw material gas 90 in the flow path 111 and the gas-phase refrigerant 191 (refrigerant hydrogen gas) in the circulation flow path 124 with the liquid-phase second refrigerant 192 (liquefied nitrogen) stored in the storage tank 131.

[0089] The heat exchanger 109 cools the raw material gas 90 in the flow path 111 and the refrigerant 191 before expansion with the liquid-phase refrigerant 191 (refrigerant liquid hydrogen) of the refrigeration cycle 103.

[0090] The cooling method according to the second embodiment includes a step of assisting the compression power of the compression unit 121 of the refrigeration cycle 103 by expanding the raw material gas 90. That is, the auxiliary expansion unit 105 expands the raw material gas 90 at a low temperature and high pressure (pressure P11) received from the flow path 111. The auxiliary expansion unit 105 rotationally drives the expansion turbine 113 by expanding the raw material gas 90, and assists the compression power of the compression unit 121 (compression turbine 127) connected to the expansion turbine 113. Then, the auxiliary expansion unit 105 lowers the temperature by expanding the raw material gas 90 from the pressure P11 to the pressure P12 (<P11), and liquefies the raw material gas 90 due to the temperature drop. As a result, the raw material gas 90 becomes a liquefied gas (liquid hydrogen) and is sent out from the lead-out path 112.

[0091] [Modification Example of the Second Embodiment] FIG. 7 is a schematic configuration diagram showing a cooling device 101A according to a modification example of the second embodiment. In the cooling device 101A, the connection of the flow path 111 to the auxiliary expansion unit 105 is different from that of the cooling device 101 of the second embodiment shown in FIG. 6. Further, the cooling device 101A in FIG. 7 further includes an expansion valve 140 that expands and liquefies the raw material gas 90.

[0092] In the cooling device 101A of FIG. 7, the flow path 111 passes through the auxiliary expansion unit 105 from the gas introduction unit 102, then passes through the heat exchange unit 104 (heat exchangers 107, 108, and 109), and is connected to the expansion valve 140.

[0093] The auxiliary expansion part 105 receives the raw material gas 90 before it is cooled by the heat exchange part 104. The raw material gas 90 is introduced into the gas introduction part 102 in a state compressed to the pressure P11 and is supplied directly (without passing through the heat exchange part 104) to the auxiliary expansion part 105. The auxiliary expansion part 105 expands the raw material gas 90 at the pressure P11 to the pressure P13. The auxiliary expansion part 105 assists the compression power of the compression part 121 of the refrigeration cycle 103 by expanding the raw material gas 90. Also, the auxiliary expansion part 105 lowers the temperature of the raw material gas 90 by expanding the raw material gas 90. In this way, the auxiliary expansion part 105 expands the raw material gas 90 received from the gas introduction part 102, thereby assisting the compression power of the compression part 121 and lowering the temperature of the raw material gas 90 and sending it to the heat exchange part 104. The pressure P11 is, for example, about 30 MPa, and the pressure P13 is, for example, greater than 0.1 MPa and about 1 MPa or less. The auxiliary expansion part 105 receives the raw material gas 90 at about 20°C, for example, and lowers the temperature of the raw material gas 90 to about -50°C by expansion.

[0094] Thus, in the cooling device 101 of the second embodiment shown in FIG. 6, the auxiliary expansion part 105 is arranged at the rear stage of the heat exchange part 104 and functions to liquefy by expanding the raw material gas 90. However, in the cooling device 101A according to the modified example, the auxiliary expansion part 105 is arranged at the front stage of the heat exchange part 104 and functions to precool the raw material gas 90 introduced into the device.

[0095] On the other hand, in both the cooling device 101 of the second embodiment shown in FIG. 6 and the cooling device 101A according to the modified example, the expansion turbine 113 is rotationally driven by expanding the raw material gas 90, and the point of assisting the compression power of the compression part 121 (compression turbine 127) connected to the expansion turbine 113 is the same.

[0096] In the cooling device 101A according to the modified example, the raw material gas 90 in a state expanded to the pressure P13 by the auxiliary expansion part 105 passes through the heat exchanger 107, the heat exchanger 108, and the heat exchanger 109 in sequence, is cooled, and then is supplied to the expansion valve 140.

[0097] The expansion valve 140 expands the raw material gas 90 (raw material hydrogen gas). The expansion valve 140 is composed of, for example, a Joule-Thomson valve. The expansion valve 140 cools the raw material gas 90 at pressure P13 by expanding it to pressure P14 (<P13), and liquefies the gaseous raw material gas 90. The expansion valve 140 is connected to the outlet passage 112. The expansion valve 140 sends out the liquefied gas obtained by liquefying the raw material gas 90 to the outlet passage 112. For example, the expansion valve 140 expands the raw material gas 90 at about 1 MPa to about 0.1 MPa and cools it to the liquefaction temperature (about -253°C).

[0098] Other configurations of the cooling device 101A according to the modified example are the same as those of the cooling device 101 according to the second embodiment.

[0099] [Third Embodiment] FIG. 8 is a schematic configuration diagram showing a cooling device 201 according to the third embodiment. In the third embodiment, similar to the first and second embodiments, the cooling device 201 is configured as a liquefaction device that cools and liquefies the raw material gas 90, but the method for reducing the prime mover power is different.

[0100] The cooling device 201 according to the third embodiment includes a gas introduction part 202, a refrigeration cycle 203, a pressure increasing valve 204, and a heat exchange part 205. Further, the cooling device 201 configured as a liquefaction device for the raw material gas 90 further includes an expansion valve 221 and a liquid tank 222. The heat exchange part 205 includes a heat exchanger 206, a heat exchanger 207, and a heat exchanger 208. The cooling device 201 according to the third embodiment is a cycle provided with a pressure increasing valve 204 based on the Brayton cycle.

[0101] The gas introduction part 202 receives the raw material gas 90 from the raw material gas supply source 23. In the cooling device 201 according to the third embodiment, the raw material gas 90 received by the gas introduction part 202 may be pre-compressed or may not be compressed. In the example of FIG. 8, the gas introduction part 202 receives the uncompressed raw material gas 90. The pressure of the raw material gas 90 is set to a pressure P21 equivalent to the atmospheric pressure (about 0.1 MPa). The gas introduction part 202 is connected to the compression part 231 of the refrigeration cycle 203 through the flow path 211.

[0102] The refrigeration cycle 203 includes a compression section 231 that compresses the raw material gas 90 and an expansion section 232 that expands the compressed raw material gas 90. In the example of FIG. 8, the expansion section 232 includes a first expansion section 233 and a second expansion section 234. The refrigeration cycle 203 has a circulation flow path 235 that circulates the raw material gas 90 through the compression section 231 and the expansion section 232. In the third embodiment, the refrigeration cycle 203 circulates a part of the raw material gas 90 as a refrigerant and cools the other part of the raw material gas 90 as a cooling target.

[0103] The circulation flow path 235 includes a high-pressure side portion 236A that leads from the compression section 231 to the expansion section 232 and a low-pressure side portion 236B that leads from the expansion section 232 to the compression section 231.

[0104] The compression section 231 includes a compressor having a compression mechanism and a motor that drives the compression mechanism. The compression method of the compressor is not particularly limited. The compression section 231 includes a cooling mechanism for removing the heat of the raw material gas 90 accompanying compression. The cooling method of the cooling mechanism is not particularly limited, but for example, it is a water-cooled type. The compression section 231 receives the raw material gas 90 from the gas introduction section 202 through the flow path 211. Also, the compression section 231 receives the circulating raw material gas 90 from the low-pressure side portion 236B of the circulation flow path 235. Further, the compression section 231 receives the raw material gas 90 discharged from the pressure increasing valve 204 through the exhaust path 215. The compression section 231 compresses the raw material gas 90 received from these respective parts and sends it out to the flow path 212. The compression section 231 compresses the raw material gas 90 to a pressure P22 higher than the pressure P21.

[0105] The flow path 212 is a branched flow path that branches into two, namely the flow path 213 and the high-pressure side portion 236A (circulation flow path 235). The flow path 212 divides the high-pressure raw material gas 90 compressed by the compression unit 231 into two parts, namely the object to be cooled and the refrigerant, and supplies them to the flow path 213 and the high-pressure side portion 236A of the refrigeration cycle 203 respectively. The flow path 213 is connected to the booster valve 204. The flow path 213 supplies the raw material gas 90 to be cooled to the booster valve 204. The raw material gas 90 serving as the refrigerant is supplied to the high-pressure side portion 236A of the refrigeration cycle 203. Therefore, the compression unit 231 supplies a part of the compressed raw material gas 90 to the booster valve 204 and circulates the remaining part of the compressed raw material gas 90 in the refrigeration cycle 203.

[0106] The high-pressure side portion 236A branches into a high-pressure flow path 237 connected to the first expansion portion 233 and a high-pressure flow path 238 connected to the second expansion portion 234. The high-pressure side portion 236A branches into the high-pressure flow path 237 and the high-pressure flow path 238 at a branch point between the heat exchanger 206 and the heat exchanger 207. The high-pressure flow path 237 passes through the heat exchanger 207 and the heat exchanger 208 and is connected to the first expansion portion 233. The high-pressure flow path 238 is directly connected to the second expansion portion 234 (without passing through the heat exchange portion) from the branch point.

[0107] The first expansion portion 233 and the second expansion portion 234 include expansion turbines. The first expansion portion 233 and the second expansion portion 234 lower the temperature by expanding the inflowing raw material gas 90.

[0108] The first expansion portion 233 expands the raw material gas 90 received from the high-pressure flow path 237 and sends it out to the low-pressure side portion 236B. The low-pressure side portion 236B is connected to the compression unit 231 from the first expansion portion 233 by passing through the heat exchanger 208, the heat exchanger 207, and the heat exchanger 206 in sequence. The second expansion portion 234 expands the raw material gas 90 received from the high-pressure flow path 238 and sends it out to the connection path 239. The connection path 239 is connected to the low-pressure side portion 236B from the second expansion portion 234. The connection path 239 is connected to the low-pressure side portion 236B at a connection position between the heat exchanger 208 and the heat exchanger 207.

[0109] The refrigeration cycle 203 cools the source gas 90, which becomes the refrigerant sent from the compression unit 231 to the high-pressure side portion 236A, in the heat exchanger 206 and then divides and supplies it to the first expansion unit 233 and the second expansion unit 234. The refrigeration cycle 203 expands and reduces the temperature of the source gas 90 cooled by the heat exchanger 207 and the heat exchanger 208 in the first expansion unit 233 and then passes it as the refrigerant through the heat exchanger 208, the heat exchanger 207, and the heat exchanger 206 in this order. Further, the refrigeration cycle 203 expands and reduces the temperature of the source gas 90 in the second expansion unit 234 and then merges it into the low-pressure side portion 236B via the connection path 239 and passes it through the heat exchanger 207 and the heat exchanger 206 in this order. The refrigeration cycle 203 cools the source gas 90 passing through the high-pressure side portion 236A and the source gas 90 to be cooled (the second portion B2 described later) by the low-temperature and low-pressure source gas 90 flowing through the low-pressure side portion 236B.

[0110] The pressure boosting valve 204 is a device that divides the supplied fluid and compresses the other fluid using the energy of the pressure of one fluid. The pressure boosting valve 204 is connected to the flow path 213, the flow path 214, and the exhaust path 215. The pressure boosting valve 204 receives the source gas 90 to be cooled from the flow path 213. The pressure boosting valve 204 compresses the second portion B2 of the source gas 90 by the expansion energy of the first portion B1 of the received source gas 90. The pressure boosting valve 204 expands the first portion B1 to a pressure P23 lower than the pressure P22. The pressure boosting valve 204 compresses the second portion B2 to a pressure P24 higher than the pressure P22. The pressure boosting valve 204 sends out the compressed second portion B2 to the flow path 214. The flow path 214 is connected to the expansion valve 221 through the heat exchanger 206, the heat exchanger 207, and the heat exchanger 208. The pressure boosting valve 204 sends out the expanded first portion B1 to the exhaust path 215. Thereby, the pressure boosting valve 204 sends the expanded first portion B1 to the compression unit 231.

[0111] The first portion B1 discharged from the pressure increasing valve 204 is compressed in the compression section 231 together with the raw material gas 90 introduced from the gas introduction section 202 into the compression section 231 and the raw material gas 90 returned from the low-pressure side portion 236B to the compression section 231, and is sent out to the flow path 212. The raw material gas 90 including the first portion B1 is compressed by the compression section 231 and returned to the original pressure P22. A part of the raw material gas 90 to be cooled among the raw material gas 90 sent out from the compression section 231 is sent to the pressure increasing valve 204 via the flow path 213. In this way, the pressure increasing valve 204 compresses the second portion B2 by the first portion B1 among the raw material gas 90 compressed to the predetermined pressure P22 by the compression section 231, and the compression section 231 recompresses the first portion B1 expanded by the pressure increasing valve 204 to the predetermined pressure P22 and supplies it to the pressure increasing valve 204.

[0112] The heat exchangers 206, 207, and 208 each perform heat exchange between a plurality of fluids. The heat exchangers 206, 207, and 208 each have one or more high-temperature side flow paths through which a high-temperature side fluid flows and one or more low-temperature side flow paths through which a low-temperature side fluid flows. The heat exchangers 206, 207, and 208 cool the fluid flowing through the high-temperature side flow path by transferring the heat of the fluid flowing through the high-temperature side flow path to the fluid flowing through the low-temperature side flow path. The heat exchangers 206, 207, and 208 each have an ortho-para conversion section 240 including a catalyst for promoting the ortho-para conversion of the raw material gas 90 (hydrogen). The catalyst of the ortho-para conversion section 240 is provided in the passage portion through which the raw material gas 90 flows so as to contact the raw material gas 90.

[0113] The heat exchangers 206, 207, and 208 are respectively arranged across the high-pressure side portion 236A and the low-pressure side portion 236B of the circulation flow path 235 and the flow path 214. The heat exchangers 206, 207, and 208 cool the source gas 90 (the high-pressure second portion B2 to be cooled) flowing through the flow path 214 by the source gas 90 (the low-temperature and low-pressure source gas 90 that functions as a refrigerant) flowing through the low-pressure side portion 236B. In this way, the heat exchange section 205 (the heat exchangers 206, 207, and 208) cools the second portion B2 compressed by the booster valve 204 with the source gas 90 flowing through the refrigeration cycle 203. Also, the heat exchangers 206, 207, and 208 cool the source gas 90 flowing through the high-pressure side portion 236A by the source gas 90 flowing through the low-pressure side portion 236B of the circulation flow path 235.

[0114] The expansion valve 221 is connected to the flow path 214 and the flow path 216. The expansion valve 221 receives the second portion B2 of the source gas 90 compressed by the compression section 231 and the booster valve 204 via the flow path 214. The second portion B2 is cooled by the heat exchange section 205 to a low-temperature and high-pressure state during the process of flowing through the flow path 214. The expansion valve 221 expands the second portion B2 cooled by the heat exchange section 205 to liquefy at least a part of the second portion B2. The expansion valve 221 is composed of, for example, a Joule-Thomson valve. The expansion valve 221 cools by expanding the second portion B2 of the source gas 90. At least a part of the second portion B2 that has passed through the expansion valve 221 liquefies. Therefore, the fluid flowing through the flow path 216 becomes a gas-liquid mixed phase state of the gaseous source gas 90 (the second portion B2) and the liquid-phase liquefied gas.

[0115] The flow path 216 connects the expansion valve 221 and the liquid tank 222. The liquid tank 222 receives the source gas 90 and the liquefied gas via the flow path 216. The source gas 90 and the liquefied gas flow into the liquid tank 222 and separate inside the liquid tank 222. The gaseous source gas 90 that has flowed into the liquid tank 222 and the source gas 90 generated (vaporized) inside the liquid tank 222 flow into the gas flow path 217.

[0116] (Cooling Method) Next, the cooling method according to the third embodiment will be described.

[0117] The cooling method according to the third embodiment includes a step of receiving the raw material gas 90 from the raw material gas supply source 23. That is, the gas introduction unit 202 receives the raw material gas 90 from the raw material gas supply source 23. The gas introduction unit 202 supplies the received raw material gas 90 to the compression unit 231 through the flow path 211.

[0118] The compression unit 231 compresses the raw material gas 90 supplied from the flow path 211 and sends it out to the flow path 212. The compression unit 231 compresses the raw material gas 90 at the pressure P21 to a pressure P22 greater than the pressure P21. The pressure P21 is, for example, about 0.1 MPa. The pressure P22 is, for example, about 0.8 MPa. The flow path 212 divides the high-pressure raw material gas 90 compressed by the compression unit 231 into the cooling target and the refrigerant, and supplies them to the flow path 213 and the high-pressure side portion 236A of the refrigeration cycle 203, respectively. The flow path 213 supplies the raw material gas 90 to be cooled to the pressure increasing valve 204.

[0119] The cooling method according to the third embodiment includes a step of compressing the second portion B2 of the raw material gas 90 by the expansion energy of the first portion B1 of the raw material gas 90 by the pressure increasing valve 204. The pressure increasing valve 204 divides the raw material gas 90 received from the flow path 213 into a first portion B1 and a second portion B2, and compresses the second portion B2 by expanding the first portion B1. The pressure increasing valve 204 expands the first portion B1 to the pressure P23 (<P22) and sends it out to the exhaust path 215, and compresses the second portion B2 to the pressure P24 (>P22) and sends it out to the flow path 214. The pressure P23 is, for example, about 0.1 MPa. The pressure P24 is, for example, about 1.6 MPa.

[0120] The cooling method according to the third embodiment includes a step of cooling the second portion B2 compressed by the pressure increasing valve 204 with the raw material gas 90 flowing through the refrigeration cycle 203 having a compression unit 231 that compresses the raw material gas 90 and an expansion unit 232 that expands the compressed raw material gas 90. That is, in the refrigeration cycle 203, the high-pressure gas-phase raw material gas 90 compressed by the compression unit 231 and heat-removed in the cooling mechanism is sequentially passed through the heat exchanger 206, the heat exchanger 207, and the heat exchanger 208 for cooling. The expansion unit 232 (the first expansion unit 233 and the second expansion unit 234) reduces the temperature by expanding the raw material gas 90 at a low temperature and high pressure (pressure P22). The outlet pressures of the first expansion unit 233 and the second expansion unit 234 are, for example, about 0.1 MPa. The refrigeration cycle 203 sequentially passes the low-temperature and low-pressure raw material gas 90 as a refrigerant through the heat exchanger 208, the heat exchanger 207, and the heat exchanger 206. The heat exchanger 206, the heat exchanger 207, and the heat exchanger 208 cool the raw material gas 90 (the second portion B2) flowing through the flow path 214 with the low-temperature and low-pressure raw material gas 90 of the refrigeration cycle 203. The flow path 214 supplies the cooled raw material gas 90 (the second portion B2) to the expansion valve 221.

[0121] The expansion valve 221 liquefies at least a part of the second portion B2 by expanding the second portion B2 of the raw material gas 90. The expansion valve 221 sends a fluid in a gas-liquid mixed phase state of the gas-phase raw material gas 90 (the second portion B2) and the liquid-phase liquefied gas to the liquid tank 222 through the flow path 216. Thereby, the cooling device 201 as a liquefaction device stores the generated liquefied gas (liquid hydrogen) in the liquid tank 222.

[0122] And the cooling method according to the third embodiment includes a step of compressing the first portion B1 expanded by the pressure increasing valve 204 with the compression unit 231. That is, the first portion B1 used for compressing the second portion B2 by the pressure increasing valve 204 is supplied to the compression unit 231 via the exhaust passage 215. The first portion B1, the compressed first portion B1, together with the raw material gas 90 from the gas introduction unit 202 and the raw material gas 90 from the low-pressure side portion 236B of the circulation passage 235, is compressed to the pressure P22. The compressed raw material gas 90 is split again into two in the flow passage 212 and supplied to the flow passage 213 and the high-pressure side portion 236A of the refrigeration cycle 203.

[0123] Therefore, in the third embodiment, the circulation of the raw material gas 90 by the refrigeration cycle 203 and the circulation of the raw material gas 90 (the first portion B1) between the compression unit 231 and the pressure increasing valve 204 are performed. By the circulation of the raw material gas 90 (the first portion B1) between the compression unit 231 and the pressure increasing valve 204, the raw material gas 90 (the second portion B2) to be cooled is compressed in two stages. In the third embodiment, in addition to the compression by the compression unit 231 (compression to the pressure P22), the compression by the pressure increasing valve 204 (compression to the pressure P24) is performed. Therefore, compared with the case of compressing to the pressure P24 only by the compression unit 231, the compression power in the compression unit 231 is reduced by the amount of compression work by the pressure increasing valve 204. Since the pressure increasing valve 204 performs compression without a drive source such as a motor, the energy consumed for compression is reduced by the amount of work of the pressure increasing valve 204.

[0124] [First Modification of the Third Embodiment] FIG. 9 is a schematic configuration diagram showing a cooling device 201A according to the first modification of the third embodiment. In the cooling device 201A, a pressure increasing valve is added to the cooling device 201 of the third embodiment shown in FIG. 8.

[0125] In the cooling device 201A according to the first modification example, the pressure increasing valve 204 includes a first pressure increasing valve 311 that increases the pressure of the raw material gas 90 compressed by the compression unit 231, and a second pressure increasing valve 312 that increases the pressure of the raw material gas 90 whose pressure has been increased by the first pressure increasing valve 311. In the cooling device 201A, the raw material gas 90 compressed by the compression unit 231 is increased in pressure in two stages by the first pressure increasing valve 311 and the second pressure increasing valve 312. Therefore, compared with the case of increasing the pressure with a single pressure increasing valve, the outlet pressure of the compression unit 231 can be lowered, and accordingly, the compression power of the compression unit 231 can be reduced.

[0126] In the cooling device 201A according to the first modification example, the gas introduction unit 202 receives the compressed raw material gas 90 from the raw material gas supply source 23. The pressure of the raw material gas 90 in the gas introduction unit 202 is the pressure P31. The pressure P31 is, for example, about 3 MPa.

[0127] The first pressure increasing valve 311 is connected to the flow path 211, the flow path 213, the flow path 313, and the exhaust path 314. The first pressure increasing valve 311 receives the raw material gas 90 pre-compressed from the gas introduction unit 202 through the flow path 211. The first pressure increasing valve 311 receives the raw material gas 90 compressed from the compression unit 231 through the flow path 213. The first pressure increasing valve 311 compresses the raw material gas 90 from the compression unit 231 by the expansion energy of the raw material gas 90 compressed from the gas introduction unit 202. The compression unit 231 compresses the raw material gas 90 to the pressure P32. The first pressure increasing valve 311 compresses the raw material gas 90 compressed to the pressure P32 to the pressure P33 (>P32). The pressure P32 is, for example, about 0.5 MPa. The pressure P33 is, for example, about 0.8 MPa.

[0128] The first pressure increasing valve 311 supplies the raw material gas 90 compressed to the pressure P33 to the second pressure increasing valve 312 through the flow path 313. The first pressure increasing valve 311 sends the expanded raw material gas 90 to the compression unit 231 through the exhaust path 314. The outlet pressure in the exhaust path 314 is, for example, about 0.1 MPa.

[0129] The second supercharging valve 312 is connected to the flow path 313, the exhaust path 215, and the flow path 214. The second supercharging valve 312 divides the raw material gas 90 supercharged by the first supercharging valve 311 into a first portion B1 and a second portion B2, and compresses the second portion B2 by the expansion energy of the first portion B1. The second supercharging valve 312 compresses the second portion B2 of the raw material gas 90 to a pressure P34 (>P33). The pressure P34 is, for example, about 1.6 MPa.

[0130] The second supercharging valve 312 sends the raw material gas 90 (second portion B2) compressed to the pressure P34 to the expansion valve 221 via the flow path 214. The second supercharging valve 312 sends the expanded raw material gas 90 (first portion B1) to the compression section 231 via the exhaust path 215. The outlet pressure in the exhaust path 215 is, for example, about 0.1 MPa.

[0131] The compression section 231 receives and compresses the raw material gas 90 supplied from the first supercharging valve 311 via the exhaust path 314, the raw material gas 90 (first portion B1) supplied from the second supercharging valve 312 via the exhaust path 215, and the raw material gas 90 supplied from the low-pressure side portion 236B of the circulation flow path 235. The compression section 231 branches the raw material gas 90 compressed to the pressure P32 in the flow path 212 and sends it to the first supercharging valve 311 and the high-pressure side portion 236A of the refrigeration cycle 203.

[0132] Other configurations of the cooling device 201A according to the first modification are the same as those of the cooling device 201 according to the third embodiment.

[0133] [Second Modification of the Third Embodiment] FIG. 10 is a schematic configuration diagram showing a cooling device 201B according to the second modification of the third embodiment. In the cooling device 201B, a cooling section 321 is added to the cooling device 201 of the third embodiment shown in FIG. 8.

[0134] The cooling device 201B according to the second modification includes a cooling unit 321 that cools the raw material gas 90 using the refrigerant 322. The cooling unit 321 supplies the low-temperature refrigerant 322 to the heat exchange unit 205 and cools the second portion B2 of the raw material gas 90 sent out from the pressure increasing valve 204. In the example of FIG. 10, the cooling unit 321 includes a refrigerant tank 323. The refrigerant tank 323 is connected to the refrigerant flow path 324. The refrigerant flow path 324 passes through the heat exchanger 325 of the heat exchange unit 205. The refrigerant 322 is not particularly limited, but when cooling hydrogen gas as the raw material gas 90, for example, it is nitrogen (liquefied nitrogen). The refrigerant tank 323 stores liquefied nitrogen as the refrigerant 322 and circulates the liquefied nitrogen through the refrigerant flow path 324.

[0135] The heat exchange unit 205 includes the heat exchanger 325 in addition to the heat exchangers 206, 207, and 208. The heat exchanger 325 is arranged in the front stage of the heat exchanger 206. The heat exchanger 325 is arranged so as to straddle the flow path 214 through which the second portion B2 sent out from the pressure increasing valve 204 flows, the circulation flow path 235 (the high-pressure side portion 236A and the low-pressure side portion 236B), and the refrigerant flow path 324. The heat exchanger 325 pre-cools the raw material gas 90 flowing through the flow path 214 and the circulation flow path 235 by the refrigerant 322 flowing through the refrigerant flow path 324. Thereby, since the temperature of the raw material gas 90 in the refrigeration cycle 203 can be lowered, the load of the compression unit 231 can be reduced. The heat exchanger 325 has an ortho-para conversion unit 240, similar to the heat exchangers 206, 207, and 208.

[0136] In addition, in this second modification, instead of providing the refrigerant tank 323 in the cooling unit 321, a refrigeration cycle using the refrigerant 322 may be provided.

[0137] Other configurations of the cooling device 201B according to the second modification are the same as those of the cooling device 201 according to the third embodiment.

[0138] [Third Modification of the Third Embodiment] FIG. 11 is a schematic configuration diagram showing a cooling device 201C according to a third modification of the third embodiment. In the cooling device 201 of the third embodiment shown in FIG. 8, an example is shown in which the high-pressure side portion 236A of the circulation flow path 235 is branched into two, and a parallel two-stage cycle in which the first expansion portion 233 and the second expansion portion 234 are provided in parallel. However, in the cooling device 201C shown in FIG. 11, the high-pressure side portion 236A of the circulation flow path 235 is a non-branched flow path, and a series two-stage cycle in which the first expansion portion 233 and the second expansion portion 234 are provided in series is adopted.

[0139] In the cooling device 201C according to the third modification, the high-pressure side portion 236A of the circulation flow path 235 is composed of a first flow path 331 connecting the compression portion 231 and the second expansion portion 234, and a second flow path 332 connecting the second expansion portion 234 and the first expansion portion 233. Therefore, the high-pressure side portion 236A connects the second expansion portion 234 and the first expansion portion 233 in series without branching.

[0140] A heat exchanger 206 is disposed in the first flow path 331. The high-pressure raw material gas 90 that branches from the flow path 212 and flows into the refrigeration cycle 203 (first flow path 331) is cooled in the heat exchanger 206 and then supplied to the second expansion portion 234. The second expansion portion 234 performs first-stage expansion on the raw material gas 90 received from the first flow path 331. The second expansion portion 234 supplies the raw material gas 90 whose temperature has decreased due to expansion to the first expansion portion 233 via the second flow path 332.

[0141] A heat exchanger 208 is disposed in the second flow path 332. The medium-pressure raw material gas 90 that flows into the second flow path 332 from the second expansion portion 234 is cooled in the heat exchanger 208 and then supplied to the first expansion portion 233. The first expansion portion 233 performs second-stage expansion on the raw material gas 90 received from the second flow path 332. The first expansion portion 233 sends out the raw material gas 90 whose temperature has decreased due to expansion to the low-pressure side portion 236B of the circulation flow path 235.

[0142] In the cooling device 201C according to the third modification example, the second expansion part 234 and the first expansion part 233 are arranged in series, and since it is not necessary to merge the raw material gas 90 from the second expansion part 234 into the low-pressure side part 236B, the heat exchanger 207 and the connection path 239 are not provided. The heat exchange part 205 includes two heat exchangers, namely the heat exchanger 206 and the heat exchanger 208. The low-temperature and low-pressure raw material gas 90 flowing from the first expansion part 233 into the low-pressure side part 236B sequentially passes through the heat exchanger 208 and the heat exchanger 206, cools the raw material gas 90 flowing through the high-pressure side part 236A and the raw material gas 90 (the second part B2) flowing through the flow path 214, and then is returned to the compression part 231.

[0143] Other configurations of the cooling device 201B according to the third modification example are the same as those of the cooling device 201 according to the third embodiment.

[0144] [Fourth Modification Example of the Third Embodiment] FIG. 12 is a schematic configuration diagram showing a cooling device 201D according to the fourth modification example of the third embodiment. In the cooling device 201C shown in FIG. 11, an example is shown in which the refrigeration cycle 203 is a series two-stage cycle in which the first expansion part 233 and the second expansion part 234 are provided in series in the circulation flow path 235. However, in the cooling device 201D according to the fourth modification example, while providing a refrigeration cycle 203 with only one-stage expansion part, the raw material gas 90 is pre-cooled by a cooling part 321 using the refrigerant 322.

[0145] In the cooling device 201D according to the fourth modification example, the refrigeration cycle 203 includes a single-stage expansion part 232. The expansion part receives the high-pressure raw material gas 90 from the high-pressure side part 236A of the circulation flow path 235, expands it, and sends out the raw material gas 90 whose temperature has decreased due to the expansion to the low-pressure side part 236B.

[0146] The cooling device 201D includes a cooling part 321 that cools the raw material gas 90 using the refrigerant 322. The configuration of the cooling part 321 is the same as that of the second modification example.

[0147] The heat exchange unit 205 includes a heat exchanger 208 and a heat exchanger 325. The heat exchanger 208 cools the source gas 90 flowing through the high-pressure side portion 236A and the source gas 90 (second portion B2) sent from the pressure increasing valve 204 to the flow path 214 by the low-temperature and low-pressure source gas 90 sent from the single-stage expansion portion 232 to the low-pressure side portion 236B.

[0148] The heat exchanger 325 is arranged in front of the heat exchanger 208. The heat exchanger 325 precools the source gas 90 flowing through the flow path 214 and the circulation flow path 235 by the refrigerant 322 flowing through the refrigerant flow path 324.

[0149] In this fourth modification, similar to the second modification, instead of providing the refrigerant tank 323 in the cooling portion 321, a refrigeration cycle using the refrigerant 322 may be provided.

[0150] Other configurations of the cooling device 201D according to the fourth modification are the same as those of the cooling device 201 according to the third embodiment.

[0151] [Fifth Modification of the Third Embodiment] FIG. 13 is a schematic configuration diagram showing a cooling device 201E according to a fifth modification of the third embodiment. The cooling device 201E according to the fifth modification changes the expansion portion 232 of the fourth modification shown in FIG. 12 from a single stage to a series two-stage configuration of a first expansion portion 233 and a second expansion portion 234.

[0152] In the cooling device 201E according to the fifth modification, the high-pressure side portion 236A of the circulation flow path 235 is composed of a first flow path 331 connecting the compression portion 231 and the second expansion portion 234, and a second flow path 332 connecting the second expansion portion 234 and the first expansion portion 233. Therefore, the high-pressure side portion 236A connects the second expansion portion 234 and the first expansion portion 233 in series without branching. The configuration of the expansion portion 232 is the same as that of the third modification shown in FIG. 11.

[0153] The high-pressure raw material gas 90 sent from the compression section 231 to the high-pressure side portion 236A of the refrigeration cycle 203 is precooled by the refrigerant 322 in the cooling section 321 in the heat exchanger 325, then cooled in the heat exchanger 206, and supplied to the second expansion section 234. The medium-pressure raw material gas 90 that has been expanded in the second expansion section 234 and whose temperature has decreased is cooled in the heat exchanger 208 and supplied to the first expansion section 233. The low-pressure raw material gas 90 that has been expanded in the first expansion section 233 and whose temperature has decreased is sent out to the low-pressure side portion 236B of the refrigeration cycle 203. The low-temperature and low-pressure raw material gas 90 flowing from the first expansion section 233 into the low-pressure side portion 236B sequentially adds the heat exchangers 208 and 206, cools the raw material gas 90 flowing through the high-pressure side portion 236A and the raw material gas 90 (second portion B2) flowing through the flow path 214, and then is returned to the compression section 231.

[0154] Other configurations of the cooling device 201E according to the fifth modification are the same as those of the cooling device 201D according to the fourth modification.

[0155] [Sixth Modification of the Third Embodiment] FIG. 14 is a schematic configuration diagram showing a cooling device 201F according to the sixth modification of the third embodiment. In the cooling device 201F, unlike the cooling device 201 of the third embodiment based on the Brayton cycle, it is based on the Claude cycle.

[0156] In the cooling device 201F according to the sixth modification, the booster valve 204 is incorporated into a part of the refrigeration cycle 203. The compression section 231 and the booster valve 204 are connected in series by a flow path 341 without branching. In the circulation flow path 235 of the refrigeration cycle 203, a compression section 231, a booster valve 204, an expansion section 232, an expansion valve 221, and a liquid tank 222 are provided. Also, a heat exchange section 205 is arranged in the circulation flow path 235. The heat exchange section 205 includes a heat exchanger 206, a heat exchanger 207, and a heat exchanger 208.

[0157] The circulation flow path 235 includes a flow path 341 connecting the compression section 231 and the pressure increasing valve 204, a branched flow path 342 connecting the pressure increasing valve 204 with the expansion section 232 and the expansion valve 221, a flow path 343 connecting the expansion valve 221 and the liquid tank 222, and a return flow path 344 connecting the liquid tank 222 and the compression section 231.

[0158] A flow path 345 from the gas introduction section 202 is connected to the return flow path 344. The raw material gas 90 received by the gas introduction section 202 is an uncompressed, non-compressed gas. The flow path 345 is connected to the return flow path 344 at a position between the compression section 231 and the heat exchanger 206. The raw material gas 90 supplied to the gas introduction section 202 merges with the raw material gas 90 flowing in the return flow path 344 and is supplied to the compression section 231.

[0159] The compression section 231 receives the low-pressure raw material gas 90 from the return flow path 344, compresses it, and sends the high-pressure raw material gas 90 to the flow path 341. The compression section 231 supplies all of the compressed raw material gas 90 to the pressure increasing valve 204. The pressure P41 at the outlet of the compression section 231 is, for example, about 0.8 MPa.

[0160] In addition to the flow path 341 and the flow path 342, the pressure increasing valve 204 is connected to the exhaust path 346. The pressure increasing valve 204 receives the medium-pressure raw material gas 90 from the compression section 231 via the flow path 341. The pressure increasing valve 204 compresses the second portion B2 of the raw material gas 90 by the expansion energy of the first portion B1 of the received raw material gas 90. The pressure increasing valve 204 sends the compressed high-pressure second portion B2 to the flow path 342. The pressure P42 of the second portion B2 at the outlet of the pressure increasing valve 204 is, for example, about 1.6 MPa. The pressure increasing valve 204 sends the expanded low-pressure first portion B1 to the exhaust path 346. Thereby, the pressure increasing valve 204 sends the expanded first portion B1 to the compression section 231. The pressure P43 of the first portion B1 at the outlet of the pressure increasing valve 204 is, for example, about 0.1 MPa.

[0161] The flow path 342 branches into a high-pressure flow path 237 and a high-pressure flow path 238 at a branch point between the heat exchanger 206 and the heat exchanger 207. The high-pressure flow path 237 passes through the heat exchanger 207 and the heat exchanger 208 and is connected to the expansion valve 221. The high-pressure flow path 238 is directly connected to the expansion section 232 from the branch point (without passing through the heat exchange section). Therefore, a part C1 of the second portion B2 of the raw material gas 90 pressurized by the pressure increasing valve 204 is supplied to the expansion section 232, and the remainder C2 of the second portion B2 is supplied to the expansion valve 221 through the heat exchanger 207 and the heat exchanger 208.

[0162] The expansion section 232 receives the medium-pressure raw material gas 90 (second portion B2) through the high-pressure flow path 238. The expansion section 232 expands a part C1 of the second portion B2 of the raw material gas 90 pressurized by the pressure increasing valve 204. The outlet pressure of the expansion section 232 is, for example, about 0.1 MPa. The expansion section 232 expands the raw material gas 90 received from the high-pressure flow path 238 to lower the temperature and sends it to the connection path 239. The connection path 239 is connected to the return flow path 344 at a connection position between the heat exchanger 207 and the heat exchanger 208.

[0163] Therefore, a part C1 of the second portion B2 that has been expanded by the expansion section 232 and has a lower temperature and lower pressure is sent through the connection path 239 to the return flow path 344 and passes through the heat exchanger 207. In the heat exchanger 207, the remainder C2 sent to the high-pressure flow path 237 is cooled by a part C1 of the second portion B2 sent to the high-pressure flow path 238 among the second portion B2 of the raw material gas 90 pressurized by the pressure increasing valve 204. In this way, the heat exchange section 205 cools the remainder C2 of the second portion B2 with a part C1 of the second portion B2 expanded by the expansion section 232.

[0164] The expansion valve 221 receives the low-temperature medium-pressure raw material gas 90 (remainder C2 of the second portion B2) cooled in the heat exchange section 205 through the high-pressure flow path 237. The expansion valve 221 expands the second portion B2 cooled by the heat exchange section 205 to liquefy at least a part of the second portion B2. The outlet pressure of the expansion valve 221 is, for example, about 0.1 MPa. The second portion B2 that has passed through the expansion valve 221 is stored in the liquid tank 222 in a gas-liquid mixed phase state.

[0165] The gaseous raw material gas 90 that has flowed into the liquid tank 222 and the return gas containing the (vaporized) raw material gas 90 generated within the liquid tank 222 flow through the return flow path 344, cool the raw material gas 90 (the remainder C2 of the second part B2) in the high-pressure flow path 237 in the heat exchanger 208, and then merge with the raw material gas 90 from the expansion part 232 at the connection position with the connection path 239. The merged return gas cools the raw material gas 90 (the remainder C2 of the second part B2) in the high-pressure flow path 237 by passing through the heat exchanger 207, and cools the raw material gas 90 (the second part B2) in the flow path 342 by passing through the heat exchanger 206. The return gas that has passed through the heat exchanger 206 merges with the raw material gas 90 from the flow path 345 and is supplied to the compression part 231.

[0166] Other configurations of the cooling device 201F according to the sixth modification example are the same as those of the cooling device 201 according to the third embodiment.

[0167] [Seventh Modification Example of the Third Embodiment] FIG. 15 is a schematic configuration diagram showing a cooling device 201G according to the seventh modification example of the third embodiment. In the cooling device 201G, a cooling part 321 is added to the cooling device 201F according to the sixth modification example of FIG. 14.

[0168] The cooling device 201G according to the seventh modification example includes a cooling part 321 that cools the raw material gas 90 using a refrigerant 322. The cooling part 321 supplies the low-temperature refrigerant 322 to the heat exchange part 205 and cools the second part B2 of the raw material gas 90 sent out from the pressure increasing valve 204. The configuration of the cooling part 321 is the same as that of the second modification example shown in FIG. 10.

[0169] The heat exchange section 205 includes a heat exchanger 325 in addition to the heat exchangers 206, 207, and 208. The heat exchanger 325 is arranged in the upstream stage of the heat exchanger 206. The heat exchanger 325 is arranged so as to straddle a flow path 342 through which a second portion B2 sent out from the pressure increasing valve 204 flows and a return flow path 344. The heat exchanger 325 pre-cools the raw material gas 90 flowing through the flow path 342 and the return flow path 344 by the refrigerant 322 flowing through the refrigerant flow path 324. Thereby, since the temperature of the raw material gas 90 in the refrigeration cycle 203 can be decreased, the load on the compression section 231 can be reduced.

[0170] In addition, in this seventh modification, instead of providing the refrigerant tank 323 in the cooling section 321, a refrigeration cycle using the refrigerant 322 may be provided.

[0171] Other configurations of the cooling device 201G according to the seventh modification are the same as those of the cooling device 201F according to the sixth modification.

[0172] [Effects of the present embodiment] The cooling device according to the first aspect includes a gas introduction section 2 that receives the compressed raw material gas 90 from the raw material gas supply source 23, a first expansion section 3 that expands a first portion 91 of the raw material gas 90, a first heat exchange section 5 that cools a second portion 92 of the raw material gas 90 with the first portion 91 whose temperature has been decreased by expansion, and a compression section 8 that compresses the first portion 91 whose temperature has increased by heat exchange and merges it with the raw material gas 90 received from the gas introduction section 2.

[0173] According to the cooling device according to the first aspect, the pre-compressed source gas 90 is divided into a first portion 91 and a second portion 92, and the second portion 92 is cooled by the first portion 91 whose temperature has been lowered by expansion, thereby cooling the source gas 90. Then, the first portion 91 whose temperature has risen by heat exchange is compressed by the compression section 8 and merged into the source gas 90 received from the gas introduction section 2. Therefore, the compression section 8 only needs to compress a part of the source gas 90 received from the gas introduction section 2. For this reason, compared with the case of receiving the non-compressed (low-pressure) source gas 90 from the source gas supply source 23 and compressing the entire amount of the received source gas 90, the compression power for cooling the source gas 90 can be reduced.

[0174] The cooling device according to the second aspect is the cooling device according to the first aspect, and further includes a second expansion section 4 provided in front of the first expansion section 3. The first expansion section 3 further expands the first portion 91 of the source gas 90 after expansion by the second expansion section 4, and the first heat exchange section 5 cools the second portion 92 of the source gas 90 after expansion by the second expansion section 4 with the first portion 91. Thereby, the pre-compressed source gas 90 can be expanded in two stages by the second expansion section 4 and the first expansion section 3 to generate the first portion 91 at a low temperature and low pressure. By cooling the second portion 92 with the generated first portion 91 at a low temperature and low pressure, the cooling performance of the source gas 90 (the second portion 92) can be improved.

[0175] The cooling device according to the third aspect is the cooling device according to the second aspect, and further includes a second heat exchange section 6 that cools the source gas 90 before expansion by the second expansion section 4 with the second portion 92 of the source gas 90 after expansion by the second expansion section 4. The first heat exchange section 5 cools the second portion 92 that has passed through the second heat exchange section 6 with the first portion 91 expanded by the first expansion section 3. Thereby, the cooling performance of the source gas 90 (the second portion 92) can be improved by two-stage heat exchange in the first heat exchange section 5 and the second heat exchange section 6.

[0176] The cooling device according to the fourth aspect is the cooling device according to any one of the first to third aspects, and further includes an expansion valve 21 that expands the second portion 92 cooled by the first heat exchange portion 5 and liquefies at least a part of the second portion 92. Thereby, the expansion valve 21 can liquefy the raw material gas 90. Since a large compression power is required for liquefying a low-boiling point gas such as hydrogen, the effect of reducing the compression power for cooling the raw material gas 90 by the cooling device according to this aspect is particularly effectively obtained.

[0177] The cooling device according to the fifth aspect is the cooling device according to any one of the first to fourth aspects, and further includes a third heat exchange portion 7 that cools the raw material gas 90 with the refrigerant 35. Thereby, the cooling effect of the raw material gas 90 can be improved by heat exchange with the refrigerant 35 in the third heat exchange portion 7. As a result, the compression power required to obtain a desired cooling effect for the raw material gas 90 can be reduced by cooling using the refrigerant 35.

[0178] The cooling device according to the sixth aspect is the cooling device according to any one of the first to fifth aspects, and further includes a raw material gas generation device 50 that generates the raw material gas 90 from the raw material liquid and supplies the generated raw material gas 90 to the gas introduction portion 2. The raw material gas generation device 50 includes a raw material gas generation portion 53 and a pressurization portion 52 that compresses the raw material gas 90 by pressurizing and supplying the raw material liquid 95 to the raw material gas generation portion 53. Thereby, when generating the raw material gas 90 from the raw material liquid 95, the raw material gas 90 compressed by the pressurized supply of the raw material liquid 95 by the pressurization portion 52 can be obtained. The pressurization portion 52 can be configured by a liquid pump or the like for pressurizing and supplying the raw material liquid 95, and the power required to obtain the pre-compressed raw material gas 90 can be reduced as compared with the case of compressing the gaseous raw material gas 90 with a compression turbine or the like.

[0179] The cooling method according to the seventh aspect includes a step of receiving the compressed raw material gas 90 from the raw material gas supply source 23, a step of expanding the first portion 91 of the raw material gas 90, a step of cooling the second portion 92 of the raw material gas 90 with the first portion 91 whose temperature has been lowered by expansion, and a step of compressing the first portion 91 whose temperature has risen and merging it with the raw material gas 90 received from the raw material gas supply source 23.

[0180] According to the cooling method according to the seventh aspect, the pre-compressed raw material gas 90 can be divided into a first portion 91 and a second portion 92, and the raw material gas 90 can be cooled by cooling the second portion 92 with the first portion 91 whose temperature has been lowered by expansion. Then, since the first portion 91 whose temperature has risen by heat exchange is compressed and merged with the raw material gas 90 received from the raw material gas supply source 23, only a part of the received raw material gas 90 needs to be compressed. Therefore, compared with the case of receiving the non-compressed (low-pressure) raw material gas 90 from the raw material gas supply source 23 and compressing the entire amount of the received raw material gas 90, the compression power for cooling the raw material gas 90 can be reduced.

[0181] The cooling device according to the eighth aspect includes a gas introduction portion 102 that receives the compressed raw material gas 90 from the raw material gas supply source 23, a refrigeration cycle 103 that has a compression portion 121 and an expansion portion 123 and circulates the refrigerant 191, a heat exchange portion 104 that cools the raw material gas 90 with the refrigerant 191 of the refrigeration cycle 103, and an auxiliary expansion portion 105 that assists the compression power of the compression portion 121 of the refrigeration cycle 103 by expanding the raw material gas 90.

[0182] According to the cooling device according to the eighth aspect, in the cooling device 101 that has a compression portion 121 and an expansion portion 123 and cools the raw material gas 90 by the refrigeration cycle 103 that circulates the refrigerant 191, the compression power of the compression portion 121 can be reduced by only the power obtained by expanding the pre-compressed raw material gas 90. Therefore, compared with the case of receiving the non-compressed (low-pressure) raw material gas 90 from the raw material gas supply source 23 and compressing the refrigerant 191 without power assist from the auxiliary expansion portion 105, the compression power for cooling the raw material gas 90 can be reduced.

[0183] The cooling device according to the ninth aspect is the cooling device according to the eighth aspect, wherein the auxiliary expansion part 105 expands the raw material gas 90 cooled by passing through the heat exchange part 104 from the gas introduction part 102, thereby assisting the compression power of the compression part 121 and liquefying at least a part by lowering the temperature of the raw material gas 90. Thereby, not only the compression power of the compression part 121 is assisted by the expansion of the raw material gas 90 by the auxiliary expansion part 105, but also the liquefaction of the raw material gas 90 can be performed.

[0184] The cooling device according to the tenth aspect is the cooling device according to the eighth aspect, wherein the auxiliary expansion part 105 expands the raw material gas 90 received from the gas introduction part 102, thereby assisting the compression power of the compression part 121 and sending the raw material gas 90 to the heat exchange part 104 after lowering the temperature. Thereby, not only the compression power of the compression part 121 is assisted by the expansion of the raw material gas 90 by the auxiliary expansion part 105, but also the process of pre-cooling the raw material gas 90 before the cooling of the raw material gas 90 by the heat exchange part 104 can be performed.

[0185] The cooling device according to the eleventh aspect is the cooling device according to any one of the eighth aspect to the tenth aspect, wherein the compression part 121 includes a compression turbine 127 that compresses the refrigerant 191 by rotation, and the auxiliary expansion part 105 includes an expansion turbine 113 connected to the compression turbine 127. Thereby, the compression power of the compression turbine 127 can be directly assisted by the rotational power recovered by the expansion of the raw material gas 90 in the expansion turbine 113. Therefore, the auxiliary expansion part 105 can perform power assistance with high energy efficiency.

[0186] The cooling device according to the twelfth aspect is a cooling device according to any one of the eighth to eleventh aspects, further comprising a raw material gas generation device 50 that generates a raw material gas 90 from a raw material liquid 95 and supplies the generated raw material gas 90 to a gas introduction unit 102. The raw material gas generation device 50 includes a raw material gas generation unit 53 and a pressurization unit 52 that compresses the raw material gas 90 by pressurizing and supplying the raw material liquid 95 to the raw material gas generation unit 53. Thereby, when generating the raw material gas 90 from the raw material liquid 95, the pressurized raw material gas 90 compressed by the pressurized supply of the raw material liquid 95 by the pressurization unit 52 can be obtained. The pressurization unit 52 can be composed of a liquid pump or the like for pressurizing and supplying the raw material liquid 95, and can reduce the power required to obtain the pre-compressed raw material gas 90 as compared with the case of compressing the gaseous raw material gas 90 with a compression turbine or the like.

[0187] The cooling method according to the thirteenth aspect includes a step of receiving a compressed raw material gas 90 from a raw material gas supply source 23, a step of cooling the raw material gas 90 with a refrigerant 191 of a refrigeration cycle 103 having a compression unit 121 and an expansion unit 123 and circulating the refrigerant 191, and a step of assisting the compression power of the compression unit 121 of the refrigeration cycle 103 by expanding the raw material gas 90.

[0188] According to the cooling method according to the thirteenth aspect, when cooling the raw material gas 90 by the refrigeration cycle 103 having the compression unit 121 and the expansion unit 123 and circulating the refrigerant 191, the compression power of the compression unit 121 can be reduced by the amount of power obtained by expanding the pre-compressed raw material gas 90. Therefore, compared with the case of receiving an uncompressed (low-pressure) raw material gas 90 from the raw material gas supply source 23 and compressing the refrigerant 191 without power assist by expanding the raw material gas 90, the compression power for cooling the raw material gas 90 can be reduced.

[0189] The cooling device according to the 14th aspect includes a gas introduction unit 202 that receives a raw material gas 90 from a raw material gas supply source 23, a compression unit 231 that compresses the raw material gas 90, an expansion unit 232 that expands the compressed raw material gas 90, a refrigeration cycle 203 having these components, a booster valve 204 that compresses a second portion B2 of the raw material gas 90 by the expansion energy of a first portion B1 of the raw material gas 90 and sends the expanded first portion B1 to the compression unit 231, and a heat exchange unit 205 that cools the second portion B2 compressed by the booster valve 204 with the raw material gas 90 flowing through the refrigeration cycle 203.

[0190] According to the cooling device according to the 14th aspect, the compression of the raw material gas 90 can be performed in a multi-stage manner, including compression by the compression unit 231 and compression by the booster valve 204. Since the booster valve 204 compresses the second portion B2 using the expansion energy of the first portion B1 of the raw material gas 90, compression can be performed without external power. Therefore, the compression work by the compression unit 231 can be reduced by the amount of compression work by the booster valve 204. Accordingly, compared with the case where the raw material gas 90 is compressed to a desired pressure only by the compression unit 231 without using the booster valve 204, the compression power for cooling the raw material gas 90 can be reduced.

[0191] The cooling device according to the 15th aspect is the cooling device according to the 14th aspect, wherein the booster valve 204 compresses the second portion B2 by the first portion B1 among the raw material gas 90 compressed to a predetermined pressure P22 by the compression unit 231, and the compression unit 231 recompresses the first portion B1 expanded by the booster valve 204 to the predetermined pressure P22 and supplies it to the booster valve 204. Thereby, the first portion B1 used for compressing the second portion B2 in the booster valve 204 can be recompressed by the compression unit 231 and circulated and supplied to the booster valve 204. Therefore, it is not necessary to generate a loss of the raw material gas 90 associated with the compression of the raw material gas 90 (second portion B2) by the booster valve 204.

[0192] The cooling device according to the 16th aspect is the cooling device according to the 14th aspect or the 15th aspect, wherein the pressure boosting valve 204 includes a first pressure boosting valve 311 that boosts the raw material gas 90 compressed by the compression unit 231, and a second pressure boosting valve 312 that boosts the raw material gas 90 boosted by the first pressure boosting valve 311. Thereby, since the raw material gas 90 can be compressed in multiple stages by the first pressure boosting valve 311 and the second pressure boosting valve 312, the compression work by the compression unit 231 can be further reduced.

[0193] The cooling device according to the 17th aspect is the cooling device according to any one of the 14th aspect to the 16th aspect, wherein the compression unit 231 supplies a part of the compressed raw material gas 90 to the pressure boosting valve 204, and circulates the remaining part of the compressed raw material gas 90 in the refrigeration cycle 203. Thereby, a path for circulating a part of the raw material gas 90 to the pressure boosting valve 204 side and a path for circulating the remaining part of the raw material gas 90 in the refrigeration cycle 203 can be separately constructed. Thereby, it is possible to easily optimize the flow state such as the flow rate of the raw material gas 90 in each path.

[0194] The cooling device according to the 18th aspect is the cooling device according to any one of the 14th aspect to the 16th aspect, wherein the compression unit 231 supplies all of the compressed raw material gas 90 to the pressure boosting valve 204, the expansion unit 232 expands a part C1 of the second part B2 of the raw material gas 90 boosted by the pressure boosting valve 204, and the heat exchange unit 205 cools the remaining part C2 of the second part B2 by the part C1 of the second part B2 expanded by the expansion unit 232. Thereby, the remaining part C2 of the second part B2 can be effectively cooled by the part C1 of the second part B2 whose temperature has been lowered by expansion. As a result, the cooling performance of the cooling device 201 can be improved.

[0195] The cooling device according to the 19th aspect is the cooling device according to any one of the 14th to 18th aspects, and further includes an expansion valve 221 that expands the second portion B2 cooled by the heat exchange portion 205 and liquefies at least a part of the second portion B2. Thereby, the raw material gas 90 can be liquefied by the expansion valve 221. Since a large amount of compression power is required for liquefying a low-boiling point gas such as hydrogen, the effect of reducing the compression power for cooling the raw material gas 90 by the cooling device 201 according to this aspect is particularly effectively obtained.

[0196] The cooling method according to the 20th aspect includes a step of receiving the raw material gas 90 from the raw material gas supply source 23, a step of compressing the second portion B2 of the raw material gas 90 by the expansion energy of the first portion B1 of the raw material gas 90 by the pressure increasing valve 204, a compression portion 231 that compresses the raw material gas 90, and an expansion portion 232 that expands the compressed raw material gas 90. A step of cooling the second portion B2 compressed by the pressure increasing valve 204 with the raw material gas 90 flowing through the refrigeration cycle 203, and a step of compressing the first portion B1 expanded by the pressure increasing valve 204 by the compression portion 231.

[0197] According to the cooling method according to the 20th aspect, the compression of the raw material gas 90 can be performed in a multi-stage manner, including compression by the compression portion 231 and compression by the pressure increasing valve 204. Since the pressure increasing valve 204 compresses the second portion B2 using the expansion energy of the first portion B1 of the raw material gas 90, compression can be performed without external power. Therefore, the compression work by the compression portion 231 can be reduced by the amount of compression work by the pressure increasing valve 204. Therefore, compared with the case where the raw material gas 90 is compressed to a desired pressure only by the compression portion 231 without using the pressure increasing valve 204, the compression power for cooling the raw material gas 90 can be reduced.

Explanation of Reference Numerals

[0198] 1, 1A, 1B, 101, 101A, 201, 201A, 201B, 201C, 201D, 201E, 201F, 201G Cooling device 2, 102, 202 Gas introduction part 3 First expansion part 4 Second Expansion Section 5 First Heat Exchange Section 6 Second Heat Exchange Section 7 Third Heat Exchange Section 8 Compression Section 21 Expansion Valve 23 Source of Feed Gas 35 Refrigerant 50 Feed Gas Generation Device 52 Pressurization Section 53 Feed Gas Generation Section 90 Feed Gas 91 First Portion 92 Second Portion 95 Feed Liquid 103, 203 Refrigeration Cycle 104, 205 Heat Exchange Section 105 Auxiliary Expansion Section 113 Expansion Turbine 121 Compression Section 123 Expansion Section 127 Compression Turbine 191 Refrigerant 204 Boosting Valve 221 Expansion Valve 231 Compression Section 232 Expansion Section 311 First Boosting Valve 312 Second Boosting Valve B1 First Portion B2 Second Portion C1 One Part C2 Remaining Portion

Claims

1. A gas introduction section that receives the compressed source gas from a source gas supply source, a first expansion section that expands a first portion of the source gas, a first heat exchange section that cools a second portion of the source gas with the first portion whose temperature has been lowered by expansion, and a compression section that compresses the first portion whose temperature has risen by heat exchange and merges it with the source gas received from the gas introduction section, comprising a cooling device. Cooling device.

2. Further comprising a second expansion section provided upstream of the first expansion section, wherein the first expansion section further expands the first portion of the source gas after expansion by the second expansion section, and the first heat exchange section cools the second portion of the source gas after expansion by the second expansion section with the first portion, the cooling device according to Claim 1. The cooling device according to Claim 1.

3. Further comprising a second heat exchange section that cools the source gas before expansion by the second expansion section with the second portion of the source gas after expansion by the second expansion section, wherein the first heat exchange section cools the second portion that has passed through the second heat exchange section with the first portion expanded by the first expansion section, the cooling device according to Claim 2. The cooling device according to Claim 2.

4. Further comprising an expansion valve that expands the second portion cooled by the first heat exchange section to liquefy at least a part of the second portion, the cooling device according to any one of Claims 1 to 3. The cooling device according to any one of Claims 1 to 3.

5. Further comprising a third heat exchange section that cools the source gas with a refrigerant, the cooling device according to any one of Claims 1 to 3. The cooling device according to any one of Claims 1 to 3.

6. Further comprising a source gas generation device that generates the source gas from a source liquid and supplies the generated source gas to the gas introduction section, wherein the source gas generation device has a source gas generation section and a pressurization section that compresses the source gas by pressurizing and supplying the source liquid to the source gas generation section, the cooling device according to any one of Claims 1 to 3. The cooling device according to any one of Claims 1 to 3.

7. A step of receiving the compressed source gas from a source gas supply source, a step of expanding a first portion of the source gas, a step of cooling a second portion of the source gas with the first portion whose temperature has been lowered by expansion, and a step of compressing the first portion whose temperature has risen and merging it with the source gas received from the source gas supply source, comprising a cooling method. Cooling method.

8. A gas introduction section that receives the compressed source gas from a source gas supply source, A refrigeration cycle having a compression section and an expansion section for circulating a refrigerant, a heat exchange section for cooling the raw material gas with the refrigerant of the refrigeration cycle, and an auxiliary expansion section for assisting the compression power of the compression section of the refrigeration cycle by expanding the raw material gas. Cooling device.

9. The auxiliary expansion section expands the raw material gas that has passed through the heat exchange section from the gas introduction section and has been cooled, thereby assisting the compression power of the compression section and liquefying at least a part of the raw material gas by lowering the temperature of the raw material gas. The cooling device according to claim 8.

10. The auxiliary expansion section expands the raw material gas received from the gas introduction section, thereby assisting the compression power of the compression section and sending the raw material gas with its temperature lowered to the heat exchange section. The cooling device according to claim 8.

11. The compression section includes a compression turbine that compresses the refrigerant by rotation, and the auxiliary expansion section includes an expansion turbine connected to the compression turbine. The cooling device according to any one of claims 8 to 10.

12. The apparatus further includes a raw material gas generation device that generates the raw material gas from a raw material liquid and supplies the generated raw material gas to the gas introduction section, wherein the raw material gas generation device has a raw material gas generation section and a pressurization section that compresses the raw material gas by pressurizing and supplying the raw material liquid to the raw material gas generation section. The cooling device according to any one of claims 8 to 10.

13. Receiving compressed raw material gas from a raw material gas supply source; Cooling the raw material gas with the refrigerant of a refrigeration cycle having a compression section and an expansion section for circulating the refrigerant; And assisting the compression power of the compression section of the refrigeration cycle by expanding the raw material gas. Cooling method.

14. A gas introduction section for receiving raw material gas from a raw material gas supply source, a refrigeration cycle having a compression section for compressing the raw material gas and an expansion section for expanding the compressed raw material gas, a pressure increasing valve that compresses a second portion of the raw material gas by the expansion energy of a first portion of the raw material gas and sends the expanded first portion to the compression section, And a heat exchange section for cooling the second portion compressed by the pressure increasing valve with the raw material gas flowing through the refrigeration cycle. Cooling device.

15. The pressure increasing valve compresses the second part by the first part among the raw material gas compressed to a predetermined pressure by the compression part, The compression part recompresses the first part expanded by the pressure increasing valve to the predetermined pressure and supplies it to the pressure increasing valve. The cooling device according to claim 14.

16. The pressure increasing valve includes a first pressure increasing valve that increases the pressure of the raw material gas compressed by the compression part, and a second pressure increasing valve that increases the pressure of the raw material gas increased by the first pressure increasing valve. The cooling device according to claim 14.

17. The compression part supplies a part of the compressed raw material gas to the pressure increasing valve and circulates the remaining part of the compressed raw material gas in the refrigeration cycle. The cooling device according to claim 14.

18. The compression part supplies all of the compressed raw material gas to the pressure increasing valve. The expansion part expands a part of the second part of the raw material gas increased in pressure by the pressure increasing valve. The heat exchange part cools the remaining part of the second part by a part of the second part expanded by the expansion part. The cooling device according to claim 14.

19. The cooling device further includes an expansion valve that expands the second part cooled by the heat exchange part to liquefy at least a part of the second part. The cooling device according to any one of claims 14 to 18.

20. A step of receiving raw material gas from a raw material gas supply source; A step of compressing a second part of the raw material gas by the expansion energy of a first part of the raw material gas by a pressure increasing valve; A step of cooling the second part compressed by the pressure increasing valve by the raw material gas flowing through a refrigeration cycle having a compression part that compresses the raw material gas and an expansion part that expands the compressed raw material gas; A step of compressing the first part expanded by the pressure increasing valve by the compression part. A cooling method.

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