Cold recovery device for recovering cold from liquefied hydrogen source, and hydrogen supply station comprising the same

Abstract

To provide a cold recovery device that recovers cold (coldness) in a process of vaporizing liquefied hydrogen to obtain hydrogen gas, and supplies the cold (coldness) as cooling means for cooling compressed hydrogen gas before it is supplied to a fuel cell vehicle.SOLUTION: A cold recovery device 3 includes recovery means which is connected to a liquefied hydrogen evaporator 13 that evaporates liquefied hydrogen derived from a liquefied nitrogen source provided at a hydrogen supply station, and which recovers cold generated when the liquefied hydrogen evaporates. The recovery means is configured to cool a first refrigerant in a buffer tank 21 that stores the first refrigerant for a precooler 17 for cooling compressed hydrogen gas supplied from a dispenser 18 at the hydrogen supply station.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cold energy recovery device that recovers cold energy from a liquefied hydrogen source, and a hydrogen supply station equipped with the same. [Background technology]

[0002] At a Hydrogen Refueling Station, the hydrogen gas to be filled into a Fuel Cell Vehicle must be cooled to around -40°C. This is defined in the ISO protocol for hydrogen refueling stations. Currently, brine and freon freezers are used to cool to -40°C. Hydrogen supply stations that use liquefied hydrogen (LH2) as the hydrogen (H2) source vaporize the liquefied hydrogen to room temperature, then cool the compressed hydrogen gas in a dispenser. These steps result in a loss of cold energy.

[0003] In Fig. 3 of Patent Document 1, it is disclosed that the cold energy (coldness) of the liquefied hydrogen is recovered in the first heat exchanger 3, but the cold energy (coldness) is dissipated to the outside in the second heat exchanger 15. In other words, the cold energy is dissipated to the outside and is not effectively used.

[0004] Patent Document 2 discloses a configuration in which the heat transfer liquid cooled in the first heat exchanger (11) is sent as cold to the second heat exchanger (25), hydrogen sent from the buffer (19) is cooled, and the cooled hydrogen gas is supplied to a fuel cell vehicle. The heat transfer liquid is circulated and sent to the first heat exchanger (11). Patent Document 2 discloses a configuration in which the heat transfer liquid is used in the second heat exchanger (25) to cool hydrogen. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2023-517439 [Patent Document 2] US Patent Publication US2023 / 0213148 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventionally (for example, Patent Document 1), the cold energy contained in liquefied hydrogen has not been recovered and has not been used effectively. This is equivalent to not recovering the energy input during the production of liquefied hydrogen. From an ecological perspective and from the perspective of the SDGs, we must devise ways to recover energy that can be recovered. The latent heat of vaporization of liquefied hydrogen at atmospheric pressure is 446 kJ / kg, and if 5 kg is filled into each fuel cell vehicle, 2,230 kJ of energy is lost. If sensible heat is included, even more energy is lost. Recovering even a portion of this lost energy will contribute to the SDGs. In addition, Patent Document 2 is configured to use only the heat transfer liquid as the cooling medium immediately before filling, and has issues such as the difference in timing between storing in the buffer and filling with hydrogen, and inflexibility in installation.

[0007] The present disclosure provides a cold energy recovery device that recovers cold energy (coldness) in the process of vaporizing liquefied hydrogen to obtain hydrogen gas, and supplies the cold energy (coldness) as a cooling means for cooling compressed hydrogen gas before it is supplied to a fuel cell vehicle. The present invention also provides a hydrogen supply station equipped with the cold heat recovery device. We also provide a cold heat recovery device that can be retrofitted to existing hydrogen station facilities. [Means for solving the problem]

[0008] The cold heat recovery device (3) of the present disclosure is a recovery means connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen derived from a liquefied hydrogen source provided in the hydrogen supply station and that recovers a portion of the cold energy of the liquefied hydrogen; The recovery means is configured to cool the first refrigerant in a buffer tank (21) that stores a first refrigerant of a precooler (17) for cooling compressed hydrogen gas supplied from a dispenser (18) of the hydrogen supply station. The recovery means is The system may further include a heat pipe (32) connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen and having a working fluid (31) that recovers cold energy generated when the liquefied hydrogen is evaporated. The heat pipes (32, 32b) are extended to a buffer tank (21) that stores a first refrigerant of the precooler (17), and the cold of the working fluid (31) is supplied to the buffer tank (21) to cool the first refrigerant in the buffer tank (21). Examples of the working fluid (31) include fluorocarbon-based, silicon-based, and neon-based fluids. The working fluid (31) moves depending on the temperature difference between both ends (32a, 32b) of the heat pipe (32). Therefore, the working fluid (31) moves automatically when cooling is required, so a control unit or a control mechanism for controlling the movement of the working fluid (31) may or may not be provided. The liquefied hydrogen evaporator may be, for example, an air-heated type. The air-heated type evaporator may have, for example, an aluminum star fin. One end (32a) of the heat pipe (32) may be connected to the aluminum star fin. The other end (32b) of the heat pipe (32) may be provided on the outer wall of the buffer tank (21).

[0009] The recovery means is a thermoelectric conversion element (36) connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen and that recovers cold heat generated when the liquefied hydrogen is evaporated; a cooling Peltier element (37) to which electric power generated by the thermoelectric conversion element (36) is transmitted via a power transmission line (L5) and which is connected to a buffer tank (21) that stores a first refrigerant of the precooler (17); The device may include: The recovery means is A controller (38) may be provided that controls the transmission of the electric power generated by the thermoelectric conversion element (36) to the cooling Peltier element (37) (for example, the timing and duration of power transmission). The thermoelectric conversion element (36) generates electricity by the cold generated when the liquefied hydrogen is vaporized. The electricity is sent to the cooling Peltier element (37). The cooling Peltier element (37) generates cold, which cools the first refrigerant in the buffer tank (21). The liquefied hydrogen evaporator (13) may be, for example, an air-heated type evaporator. The air-heated type evaporator may have, for example, an aluminum star fin. The thermoelectric conversion element (36) may be connected to the aluminum star fin. The cooling Peltier element (37) may be provided on a wall surface of the buffer tank.

[0010] The hydrogen supply station (A1, B1) of the present disclosure is A liquefied hydrogen storage tank (11) for storing liquefied hydrogen (for example, at a temperature of −253° C.); A piping line (L1) for discharging liquefied hydrogen from the liquefied hydrogen storage tank (11); a liquefied hydrogen pump (12) provided in the piping line (L1) for sending liquefied hydrogen to a downstream stage and for increasing the pressure of the liquefied hydrogen to a constant pressure (e.g., 40 MPa); a liquefied hydrogen evaporator (13) provided in the piping line (L1) downstream of the liquefied hydrogen pump (12) and configured to vaporize liquefied hydrogen (for example, at a hydrogen gas pressure of 40 MPa to 82 MPa); a pressure accumulator unit (14) for storing hydrogen gas (for example, hydrogen gas having a pressure of 40 MPa to 82 MPa) vaporized in the liquefied hydrogen evaporator (13); a compressor (15) that compresses the hydrogen gas discharged from the pressure accumulator unit (14) to a predetermined pressure (e.g., 82 MPa or more); a high-pressure accumulator unit (16) for storing the hydrogen gas compressed by the compressor (15); a precooler (17) for cooling the compressed hydrogen gas discharged from the high-pressure accumulator unit (16) to a predetermined temperature (e.g., −40° C.); a dispenser (18) that delivers the compressed hydrogen gas cooled by the precooler (17) (cooled compressed hydrogen gas) to a hydrogen tank of a fuel cell vehicle; a refrigerant piping line (L2) for supplying a first refrigerant to the precooler (17); a buffer tank (21) provided in the refrigerant piping line (L2) for storing the first refrigerant; a liquid transfer pump (P1) for transferring the first refrigerant from the buffer tank (21) to the precooler (17); a heat exchanger (22) for cooling the first refrigerant discharged from the buffer tank (21); a refrigerant cooling piping line (L3) for returning the first refrigerant discharged from the buffer tank (21) and cooled in the heat exchanger (22) to the buffer tank (21); a liquid transfer pump (P2) provided in the refrigerant cooling piping line (L3) for transferring the first refrigerant; a refrigerator (23) that supplies a second refrigerant for cooling the first refrigerant in the heat exchanger (22); The above-mentioned cold heat recovery device (3), The device may include:

[0011] The hydrogen supply stations (A2, B2) may include a hydrogen compressor (121) instead of the liquefied hydrogen pump (12). In this configuration, the liquefied hydrogen evaporator (13) is provided in the piping line (L1) and vaporizes the liquefied hydrogen (for example, hydrogen gas pressure is 0.3 MPa to 1.2 MPa). The hydrogen compressor (121) is provided in the piping line (L1) downstream of the liquefied hydrogen evaporator (13) and compresses the hydrogen gas vaporized in the liquefied hydrogen evaporator (13) to a predetermined pressure. The compressed hydrogen gas is sent to the pressure accumulator unit (14) and stored therein. In this configuration, the compressor (15) and the high-pressure accumulator unit (16) may be omitted or may be provided.

[0012] The pressure accumulator unit (14) may be, for example, a pressure accumulator such as a tank, a buffer, a cylinder, etc. Two or more pressure accumulators may be provided. The high-pressure accumulator unit (16) may be, for example, an accumulator such as a tank, a buffer, a cylinder, etc. Two or more accumulators may be provided.

[0013] (effect) (1) The cold energy produced when liquefied hydrogen is vaporized can be used as part of the cold energy required to cool the brine in a fluorocarbon refrigerator. This is expected to contribute to energy savings in the fluorocarbon refrigerator. (2) It can also contribute from an ecological perspective and from the perspective of the SDGs. (3) Since it can utilize cold energy, it can contribute to reducing operating costs. (4) The system can be retrofitted to existing hydrogen supply station equipment. (5) By maintaining the use of a freon refrigerator, the hydrogen cooling function during refilling can be secured while the cold energy can be used to cool the brine in the freon refrigerator. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating an example of a hydrogen supply station according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of another hydrogen supply station according to the first embodiment. [Diagram 3] FIG. 11 is a diagram illustrating an example of a hydrogen supply station according to a second embodiment. [Figure 4] FIG. 11 is a diagram showing an example of another hydrogen supply station according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Several embodiments of the present invention will be described below. The embodiments described below are merely examples of the present invention. The present invention is not limited to the following embodiments, and includes various modified forms that are implemented within the scope of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0016] (Embodiment 1) The hydrogen supply station A1 of the first embodiment will be described with reference to FIG. The hydrogen supply station A1 is a pump-type station. The liquefied hydrogen storage tank 11 stores liquefied hydrogen (for example, at a temperature of −253° C.). The piping line L1 is a piping line for drawing out the liquefied hydrogen from the liquefied hydrogen storage tank 11. The piping line L1 leads to a subcooler 17. The piping line L1 may be provided with a pressure gauge, a thermometer, a control valve, etc. (not shown). The liquefied hydrogen pump 12 is provided in the piping line L1. The liquefied hydrogen pump 12 sends the liquid hydrogen to the downstream liquefied hydrogen evaporator 13, and increases the pressure of the liquid hydrogen to a constant pressure (for example, 40 MPa).

[0017] The liquefied hydrogen evaporator 13 is provided in the piping line L1 downstream of the liquefied hydrogen pump 12. The liquefied hydrogen evaporator 13 vaporizes liquefied hydrogen (for example, hydrogen gas pressure is 40 MPa to 82 MPa). In this embodiment, it is an air-heated evaporator. The pressure accumulator unit 14 stores the hydrogen gas (for example, hydrogen gas pressure is 40 MPa to 82 MPa) vaporized in the liquefied hydrogen evaporator 13. The pressure accumulator unit 14 may be provided with a thermometer and a pressure gauge. Gate valves may be provided in the piping line L1 downstream and upstream of the pressure accumulator unit 14, and pressure accumulators for storing hydrogen gas sent from the evaporator 13 can be set. In addition, a pressure accumulator for sending hydrogen gas to the compressor 15 is set.

[0018] The compressor 15 compresses the hydrogen gas delivered from any one of the pressure accumulators in the pressure accumulator unit 14 to a predetermined pressure (for example, 82 MPa or more). The high-pressure accumulator unit 16 stores the hydrogen gas compressed by the compressor 15 (compressed hydrogen gas). The high-pressure accumulator unit 16 may be provided with a thermometer and a pressure gauge. Gate valves may be provided in the piping line L1 downstream and upstream of the high-pressure accumulator unit 16, and accumulators for storing the hydrogen gas sent from the compressor 15 can be set. In addition, an accumulator for sending hydrogen gas to the subcooler 17 is set.

[0019] The subcooler 17 cools the compressed hydrogen gas derived from any of the accumulators in the high-pressure accumulator unit 16 to a predetermined temperature (for example, −40° C.). The dispenser 18 delivers the compressed hydrogen gas cooled in the precooler 17 (cooled compressed hydrogen gas) to the hydrogen tank of the fuel cell vehicle. In response to a supply request from the dispenser 18, hydrogen gas is sent from the high-pressure accumulator unit 16 to the subcooler 17, where the cooled hydrogen gas is supplied to the hydrogen tank from the nozzle of the dispenser.

[0020] The buffer tank 21 is provided in the refrigerant piping line L2 and stores the first refrigerant. The refrigerant piping line L2 is a circulation line that supplies the first refrigerant to the precooler 17 from the buffer tank 21 and returns it to the buffer tank 21. The liquid transfer pump P1 is provided in the refrigerant piping line L2. The liquid transfer pump P1 sends the first refrigerant from the buffer tank 21 to the precooler 17 and returns it to the buffer tank 21. In the precooler 17, the compressed hydrogen gas is cooled to a predetermined temperature (for example, -40°C) by the cold of the first refrigerant.

[0021] The heat exchanger 22 cools the first refrigerant discharged from the buffer tank 21. The refrigerant cooling piping line L3 is a circulation line that sends the first refrigerant discharged from the buffer tank 21 to the heat exchanger 22 and returns the cooled first refrigerant to the buffer tank 21. The liquid feed pump P2 is provided in the refrigerant cooling piping line L3. The liquid feed pump P2 sends the first refrigerant from the buffer tank 21 to the heat exchanger 22 and returns it to the buffer tank 21. The refrigerator 23 supplies a second refrigerant for cooling the first refrigerant in the heat exchanger 22 .

[0022] The cold heat recovery device 3 is connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen, and has a heat pipe 32 having a working fluid 31 that recovers the cold heat generated when the liquefied hydrogen is evaporated. The heat pipe 32 is extended to the buffer tank 21 that stores the first refrigerant of the precooler 17, and the cold of the working fluid 31 is supplied to the buffer tank 21 to cool the first refrigerant in the buffer tank 21. Examples of the working fluid 31 include fluorocarbon, silicon, and neon. The working liquid 31 is configured to move depending on the temperature difference between both ends (32a, 32b) of the heat pipe 32. Therefore, since the working liquid 31 moves automatically when cooling is required, a control unit or control mechanism for controlling the movement of the working liquid 31 may or may not be provided. The liquefied hydrogen evaporator 13 has, for example, an aluminum star fin, and one end 32a of the heat pipe 32 is connected to the aluminum star fin. The other end 32b of the heat pipe 32 is provided on the outer wall of the buffer tank 21.

[0023] (Another embodiment of the first embodiment) Fig. 2 shows a hydrogen supply station A2 according to another embodiment. Components with the same reference numerals as those in Fig. 1 have the same functions, and therefore their explanation will be omitted. The hydrogen supply station A2 is a compressor type station. The hydrogen supply station A2 is equipped with a hydrogen compressor 121 instead of the liquefied hydrogen pump 12. The liquefied hydrogen evaporator 13 is provided in the piping line L1 and vaporizes liquefied hydrogen (for example, hydrogen gas pressure is 0.3 MPa to 1.2 MPa). The hydrogen compressor 121 is provided in the piping line L1 downstream of the liquefied hydrogen evaporator 13 and compresses the hydrogen gas vaporized in the liquefied hydrogen evaporator 13 to a predetermined pressure. The compressed hydrogen gas is sent to and stored in the pressure accumulator unit 14. In this configuration, the compressor 15 and the high-pressure pressure accumulator unit 16 are omitted. The cold heat recovery device 3 is the same as that in the hydrogen supply station A1.

[0024] (Embodiment 2) Fig. 3 shows a hydrogen supply station B1 of embodiment 2. Components with the same reference numerals as those in Fig. 1 have the same functions, and therefore will not be described. The hydrogen supply station B1 is a pump-type station similar to the hydrogen supply station A1 of embodiment 1, and has the same basic configuration, but differs in the cold heat recovery device 3. The thermoelectric conversion element 36 receives cold energy and generates electric power. The thermoelectric conversion element 36 is connected to the liquefied hydrogen evaporator 13 that evaporates the liquefied hydrogen, and recovers the cold energy generated when the liquefied hydrogen is evaporated. The cooling Peltier element 37 receives electric power and generates cold heat. The electric power generated by the thermoelectric conversion element 36 is sent to the cooling Peltier element 37 via the power transmission line L5. The cooling Peltier element 37 is connected to the buffer tank 21 that stores the first refrigerant of the precooler 17. The first refrigerant in the buffer tank 21 is cooled by the generated cold heat. The controller 38 controls the transmission (for example, the timing and duration of power transmission) of the power generated by the thermoelectric conversion element 36 to the cooling Peltier element 37. The controller 38 may have a battery for storing power, and may store the power generated by the thermoelectric conversion element 36. The controller 38 may control the power of the battery to be sent to the cooling Peltier element 37 as necessary.

[0025] The thermoelectric conversion element 36 generates electricity by the cold generated when the liquefied hydrogen is evaporated, and the electricity is sent to the cooling Peltier element 37, which generates cold and cools the first refrigerant in the buffer tank 21. The liquefied hydrogen evaporator 13 may have, for example, an aluminum star fin, and the thermoelectric conversion element 36 may be connected to the aluminum star fin. The cooling Peltier element 37 may be provided on the wall surface of the buffer tank 21.

[0026] (Another embodiment of the second embodiment) Fig. 4 shows a hydrogen supply station B2 according to another embodiment. Components with the same reference numerals as those in Fig. 3 have the same functions, and therefore their explanation will be omitted. The hydrogen supply station B2 is a compressor type station. The hydrogen supply station B2 is equipped with a hydrogen compressor 121 instead of the liquefied hydrogen pump 12. The liquefied hydrogen evaporator 13 is provided in the piping line L1 and vaporizes liquefied hydrogen (for example, hydrogen gas pressure is 0.3 MPa to 1.2 MPa). The hydrogen compressor 121 is provided in the piping line L1 downstream of the liquefied hydrogen evaporator 13 and compresses the hydrogen gas vaporized in the liquefied hydrogen evaporator 13 to a predetermined pressure. The compressed hydrogen gas is sent to and stored in the pressure accumulator unit 14. In this configuration, the compressor 15 and the high-pressure pressure accumulator unit 16 are omitted. The cold heat recovery device 3 is the same as that in the hydrogen supply station B1. [Explanation of symbols]

[0027] 1 Hydrogen supply system 11 Liquid hydrogen storage tank 12 Liquid hydrogen pump 13 Liquid hydrogen evaporator 14 Accumulator Unit 15 Compressor 16 High Pressure Accumulator Unit 17 Pre-cooler 18 Dispenser 21 Buffer Tank 22 Heat exchanger 23 Refrigeration Machine 3. Cold and heat recovery equipment 31 Hydraulic Fluid 32 Heat Pipe

Claims

1. a recovery means connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen derived from a liquefied hydrogen source provided in the hydrogen supply station and that recovers cold energy generated when the liquefied hydrogen is evaporated; the recovery means cools the first refrigerant in a buffer tank that stores a first refrigerant of a precooler for cooling the compressed hydrogen gas supplied from a dispenser of the hydrogen supply station; Cold and heat recovery device.

2. The recovery means is The heat pipe is connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen and has a working fluid that recovers cold heat generated when the liquefied hydrogen is evaporated. The cold heat recovery device according to claim 1 .

3. The recovery means is a thermoelectric conversion element connected to a liquefied hydrogen evaporator that evaporates liquefied hydrogen and that recovers a portion of the cold energy of the liquefied hydrogen; a cooling Peltier element to which the electric power generated by the thermoelectric conversion element is transmitted via a power transmission line and which is connected to a buffer tank that stores a first refrigerant of a precooler; Equipped with The cold heat recovery device according to claim 1 .

4. The cold heat recovery device according to any one of claims 1 to 3, a liquefied hydrogen storage tank for storing liquefied hydrogen; a liquefied hydrogen pump that sends liquefied hydrogen to a downstream stage and pressurizes the liquefied hydrogen to a constant pressure; a liquefied hydrogen evaporator for vaporizing the liquefied hydrogen; a pressure accumulator unit for storing the hydrogen gas vaporized by the liquefied hydrogen evaporator; a precooler that cools the compressed hydrogen gas discharged from the pressure accumulator unit to a predetermined temperature; A dispenser that delivers the compressed hydrogen gas cooled by the precooler to a hydrogen tank of a fuel cell vehicle; A refrigerant piping line for supplying a first refrigerant to the precooler; a buffer tank provided in the refrigerant piping line and configured to store the first refrigerant; a heat exchanger for cooling the first refrigerant discharged from the buffer tank; a refrigerant cooling piping line for returning the first refrigerant discharged from the buffer tank and cooled by the heat exchanger to the buffer tank; a refrigerator that supplies a second refrigerant for cooling the first refrigerant in the heat exchanger; Equipped with Hydrogen refueling station.

5. The cold heat recovery device according to any one of claims 1 to 3, a liquefied hydrogen storage tank for storing liquefied hydrogen; a liquefied hydrogen evaporator for vaporizing the liquefied hydrogen; a compressor that compresses the hydrogen gas vaporized in the liquefied hydrogen evaporator; a pressure accumulator unit for storing the hydrogen gas compressed by the compressor; a precooler that cools the compressed hydrogen gas discharged from the pressure accumulator unit to a predetermined temperature; A dispenser that delivers the compressed hydrogen gas cooled by the precooler to a hydrogen tank of a fuel cell vehicle; A refrigerant piping line for supplying a first refrigerant to the precooler; a buffer tank provided in the refrigerant piping line and configured to store the first refrigerant; a heat exchanger for cooling the first refrigerant discharged from the buffer tank; a refrigerant cooling piping line for returning the first refrigerant discharged from the buffer tank and cooled by the heat exchanger to the buffer tank; a refrigerator that supplies a second refrigerant for cooling the first refrigerant in the heat exchanger; Equipped with Hydrogen refueling station.

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