A dual-pressure liquid hydrogen hydrogen refueling station system and its usage method

Abstract

The present invention discloses a liquid hydrogen refueling station technology field, and particularly relates to a dual-pressure liquid hydrogen refueling station system and a method for using the same. The refueling station system includes: a liquid hydrogen pump for the station, an autoclave, a mixer, an air heat exchanger, an electric heater, a liquid hydrogen storage tank, a medium-pressure hydrogen storage tank, a high-pressure hydrogen storage tank, a heat exchanger with cold storage, a mass flow distributor, a 70MPa hydrogen distributor, and a 35MPa hydrogen distributor. In the present invention, a low-pressure liquid hydrogen pump is used to circulate liquid hydrogen through a heat exchanger with cold storage to store a portion of the cold energy and then inject it into the autoclave. The liquid hydrogen in the autoclave is gasified and pressurized using constant volume heating. Different pipelines are used to distribute the low-temperature hydrogen and the hydrogen after gasification and heating to quickly reach the target filling temperature. Compared with traditional liquid hydrogen pressurization and gasification technology, the outlet pressure of the liquid hydrogen pump is reduced, and the system has the advantages of low energy consumption, low initial cost investment, and short feedback time of the pre-cooling system, and has 70MPa and 35MPa filling capabilities.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid hydrogen refueling stations, and in particular relates to a dual-pressure liquid hydrogen refueling station system and a method for using the same. Background Art

[0002] With the significant acceleration of the global hydrogen fuel cell vehicle (FCV) marketization process, hydrogen refueling stations (HRS), as a link between hydrogen consumption (such as FCV) and production, have become more open to the public. At present, most of the mainstream hydrogen refueling stations in China use 35MPa normal temperature high pressure hydrogen, while most of the international hydrogen refueling stations use 70MPa and liquid hydrogen refueling stations. The density of liquid hydrogen is 70.8kg / m 3 Its density is much higher than that of gaseous hydrogen, thus overcoming the limitations of gaseous hydrogen storage capacity and high pressure within the same volume. Storing liquid hydrogen at hydrogen refueling stations can further increase the station's daily refueling capacity, enabling the refueling of more hydrogen-powered vehicles. Liquid hydrogen refueling stations, with their advantages of small footprint and high transfer efficiency, are the mainstream method for hydrogen refueling stations abroad, especially heavy-duty stations.

[0003] At present, liquid hydrogen refueling stations mainly use a pressurized gasification system. This system first uses a liquid hydrogen pump to pressurize liquid hydrogen (~0.1MPa, ~20K) to 90~100MPa (~45K). After pressurization, the hydrogen has reached a supercritical state. It can be considered that pressurization and "gasification" occur simultaneously in this process; then, under the condition of constant pressure, the temperature of the supercritical hydrogen is raised to the temperature required by the hydrogen refueling station (>273K) through a heater and stored in a buffer tank; finally, the high-pressure hydrogen is injected into the vehicle from the buffer tank. In order to ensure the filling rate and final filling rate during the filling process, the high-pressure hydrogen usually needs to be pre-cooled to -40℃. Compared with the traditional method of gasification followed by pressurization, the liquid hydrogen pressurization and gasification system uses a liquid hydrogen pump instead of a compressor to reduce energy consumption to a certain extent. However, this process still has problems such as high energy consumption, high requirements for the liquid hydrogen booster pump outlet parameters to reach 90MPa, and long standby time of the pre-cooling system, resulting in low filling efficiency. At the same time, high-pressure liquid hydrogen pump equipment mostly relies on foreign imports, which limits the application and promotion of domestic 70MPa liquid hydrogen refueling stations.

[0004] Therefore, there is an urgent need for a dual-pressure liquid hydrogen refueling station system that has both 35MPa and 70MPa refueling capacities without using high-pressure liquid hydrogen pump equipment, can meet the hydrogen refueling needs of multiple scenarios, achieve efficient use of liquid hydrogen, reduce the long standby time of the pre-cooling system, improve refueling efficiency, and reduce hydrogen residual. Summary of the Invention

[0005] The object of the present invention is to provide a dual-pressure liquid hydrogen refueling station system, comprising:

[0006] The station is equipped with a liquid hydrogen storage tank, a cryogenic pump, a mass flow distributor, a heat exchanger, a constant volume temperature and pressure boosting device, a 70MPa hydrogen distributor, a gasification temperature raising device and a 35MPa hydrogen distributor, characterized in that:

[0007] The constant volume temperature increasing and pressurizing device comprises an autoclave, a medium pressure hydrogen storage tank and a high pressure hydrogen storage tank connected in parallel, the autoclave is provided with a first electric heater, a fourth control valve and a fifth control valve are provided at the input end and the output end of the autoclave respectively, a sixth control valve and a seventh control valve are provided at the input end and the output end of the medium pressure hydrogen storage tank respectively, and an eighth control valve and a ninth control valve are provided at the input end and the output end of the high pressure hydrogen storage tank respectively; and the input ends of the autoclave, the medium pressure hydrogen storage tank and the high pressure hydrogen storage tank connected in parallel intersect at a first intersection through a pipeline, and the output ends of the autoclave, the medium pressure hydrogen storage tank and the high pressure hydrogen storage tank connected in parallel intersect at a second intersection through a pipeline;

[0008] The gasification and temperature-raising device comprises an air heat exchanger, a second electric heater, and a mixer connected in series through a pipeline, and an eleventh control valve is provided between the second electric heater and the mixer;

[0009] The station liquid hydrogen storage tank, the cryogenic pump, the first control valve and the mass flow distributor are sequentially connected in series through pipelines;

[0010] The first output end of the mass flow distributor is connected to the cold side of the heat exchanger, the third control valve, and the first intersection in sequence through a pipeline, forming an input path of the heat exchanger; the second intersection is connected to the hot side of the heat exchanger, the tenth control valve, and the 70MPa hydrogen distributor in sequence through a pipeline, forming an output path of the heat exchanger;

[0011] The second output end of the mass flow distributor is connected in series with the gasification and temperature raising device, the twelfth control valve and the 35MPa hydrogen distributor through a pipeline.

[0012] The heat exchanger is provided with a cold storage device; and the first control valve, the second control valve and the mixer are sequentially connected in series through pipelines.

[0013] Furthermore, the first control valve, the second control valve and the mixer are sequentially connected in series through a pipeline.

[0014] The present invention also discloses a method for using the dual-pressure liquid hydrogen refueling station system, which is characterized by comprising the following steps:

[0015] S1: Open the first control valve to transfer the liquid hydrogen at a temperature of -253°C and a pressure of 35 MPa stored in the station's liquid hydrogen storage tank to the mass flow distributor through the cryogenic pump;

[0016] S2: The mass flow distributor injects a fixed amount of liquid hydrogen into the cold side of the heat exchanger, opens the third and fourth control valves, closes the fifth, sixth, seventh, eighth, and ninth control valves, and injects all the fixed amount of liquid hydrogen into the autoclave;

[0017] S3: closing the third control valve and the fourth control valve, and turning on the first electric heater to gasify the liquid hydrogen in the autoclave to achieve constant volume, temperature, and pressure increase;

[0018] S4: When the pressure in the autoclave is greater than or equal to the low-pressure threshold, the fourth control valve and the sixth control valve are opened to fill the medium-pressure hydrogen storage tank, and the first electric heater is continued to be turned on to further increase the pressure in the autoclave;

[0019] S5: When the pressure in the autoclave is greater than or equal to the medium pressure threshold, the sixth control valve is closed, the eighth control valve is opened, the high-pressure hydrogen storage tank is filled, and the first electric heater is continued to be turned on to further increase the pressure in the autoclave;

[0020] S6: When the pressure in the autoclave is greater than or equal to the high-pressure threshold, closing the first electric heater, the fourth control valve, and the eighth control valve to complete the filling preparation;

[0021] S7: When filling a 70MPa-class on-board hydrogen storage tank, by adjusting the opening and closing of the fifth control valve, the seventh control valve, and the ninth control valve, a tank body with a gas hydrogen pressure greater than or equal to the medium pressure threshold is selected from the autoclave, the medium-pressure hydrogen storage tank, and the high-pressure hydrogen storage tank, and the gas hydrogen in the selected tank body is injected into the hot side of the heat exchanger through a pipeline. When the gas hydrogen temperature in the hot side of the heat exchanger is less than or equal to -40°C, the tenth control valve is opened to inject the gas hydrogen into the 70MPa hydrogen distributor, thereby filling the 70MPa-class on-board hydrogen storage tank with gas hydrogen;

[0022] S8: When the gaseous hydrogen pressure in the tank selected in S7 is less than the medium pressure threshold, S7 is repeated to select a tank with a gaseous hydrogen pressure greater than or equal to the medium pressure threshold again, and the 70MPa-class on-board hydrogen storage tank is filled with gaseous hydrogen; when the gaseous hydrogen pressure in the autoclave, the medium-pressure hydrogen storage tank, and the high-pressure hydrogen storage tank are all less than the medium pressure threshold, S1-S6 are repeated to complete the filling preparation again;

[0023] S9: When filling the 35MPa-class on-board hydrogen storage tank, the mass flow distributor injects a fixed amount of liquid hydrogen into the air heat exchanger for gasification and temperature increase to form gaseous hydrogen; the gaseous hydrogen enters the second electric heater through the pipeline for further heating, and the eleventh control valve is opened to allow the gaseous hydrogen to enter the mixer; when the temperature of the gaseous hydrogen in the mixer is less than or equal to -40°C, the twelfth control valve is opened to inject the gaseous hydrogen into the 35MPa hydrogen distributor to fill the 35MPa-class on-board hydrogen storage tank;

[0024] S10: When the mass flow distributor is insufficient in liquid hydrogen, S1 is repeatedly executed to replenish the mass flow distributor with liquid hydrogen.

[0025] The low pressure threshold is 35 MPa, the medium pressure threshold is 67 MPa, and the low pressure threshold is 90 MPa.

[0026] The heat exchanger is provided with a cold storage device;

[0027] After the mass flow distributor injects a fixed amount of liquid hydrogen into the cold side of the heat exchanger in S2 and before all the fixed amount of liquid hydrogen is injected into the autoclave, the method further includes: storing the cold energy of the liquid hydrogen in the heat exchanger in the cold storage device;

[0028] When the gaseous hydrogen in the selected tank is injected into the hot side of the heat exchanger through the pipeline in S7, the cold storage device of the heat exchanger is used to cool the gaseous hydrogen in the hot side of the heat exchanger.

[0029] The first control valve, the second control valve and the mixer are connected in series in sequence through pipelines;

[0030] When the gaseous hydrogen in S9 enters the mixer, the second control valve is opened to inject liquid hydrogen into the mixer through the pipeline to cool the gaseous hydrogen in the mixer.

[0031] The technical problem to be solved by the present invention is: to reduce the outlet pressure of the cryogenic pump and break the limitation of only using foreign high-pressure liquid hydrogen pumps; the cold energy of traditional liquid hydrogen refueling stations cannot be fully utilized. In addition to liquid hydrogen gasification, hydrogen needs to be pre-cooled again during refueling, which results in high energy consumption. At the same time, the pre-cooling system has a long response time to meet hydrogen refueling needs, and the hydrogen refueling station suffers losses due to standby time.

[0032] Based on the above problems, the patent of this invention proposes a dual-pressure liquid hydrogen refueling station system and its use method, which supports the refueling of two types of on-board hydrogen storage tanks, 35MPa and 70MPa. The liquid hydrogen is gasified and pressurized by constant volume heating, and only a cryogenic pump (low-pressure liquid hydrogen pump) is needed to achieve a refueling capacity of 70MPa; at the same time, the cryogenic pump is used to mix the low-temperature liquid hydrogen and the gasified and heated hydrogen through different pipelines to achieve the refueling requirement of -40℃, so that the pre-cooling system can respond to the hydrogen refueling demand in a relatively short time, and realize the rapid refueling of the 35MPa on-board hydrogen storage tank.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1) A heat exchanger with cold storage is used to store part of the cold capacity of the liquid hydrogen, and the hydrogen is heated and heated in an autoclave to achieve constant volume and pressure boosting. A cryogenic pump is used to circulate and boost the low-pressure hydrogen after each hydrogenation, greatly reducing hydrogen waste. The hydrogen refueling station system proposed in this invention can have a hydrogenation capacity of 70MPa without the need for a high-pressure compressor, while fully utilizing the cold capacity of the liquid hydrogen, effectively reducing the operating energy consumption of the entire station.

[0035] 2) A cryogenic pump is used to directly pass hydrogen through an air heat exchanger and an electric heater to vaporize and heat it. At the same time, low-temperature hydrogen is mixed with the vaporized and heated hydrogen from another pipeline in a mixer. The mass flow rates of the two routes are adjusted by a control valve to achieve the target filling temperature. This allows for direct filling of the on-board hydrogen storage tank, further reducing the response time of the pre-cooling system when hydrogen refueling is required.

[0036] 3) The hydrogenation system has both 35MPa and 70MPa hydrogenation capacities, which can meet the hydrogenation needs of multiple scenarios. When the hydrogenation pressure requirements are not met in the autoclave and high-pressure hydrogen storage tank, a mass flow distributor can be used to distribute a portion of the mass liquid hydrogen into the autoclave, and the autoclave, medium-pressure hydrogen storage tank and high-pressure hydrogen storage tank are circulated again to fill the autoclave, medium-pressure hydrogen storage tank and high-pressure hydrogen storage tank until the pressure requirement for continuous filling of the on-board hydrogen storage tank is reached. The low-pressure gas in the hydrogen storage tank can be pressurized in the next hydrogenation cycle, effectively improving the problem of residual hydrogen in the hydrogen storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a connection structure diagram of a dual-pressure liquid hydrogen refueling station system of the present invention;

[0038] In the figure: 1-station liquid hydrogen storage tank, 2-cryogenic pump, 3-first control valve, 4-second control valve, 5-mass flow distributor, 6-heat exchanger, 7-third control valve, 8-first electric heater, 9-fourth control valve, 10-autoclave, 11-fifth control valve, 12-seventh control valve, 13-medium-pressure hydrogen storage tank, 14-sixth control valve, 15-ninth control valve, 16-high-pressure hydrogen storage tank, 17-eighth control valve, 18-tenth control valve, 19-70MPa hydrogen distributor, 20-air heat exchanger, 21-second electric heater, 22-eleventh control valve, 23-mixer, 24-twelfth control valve, 25-35MPa hydrogen distributor, 26-first intersection, 27-second intersection. DETAILED DESCRIPTION

[0039] The present invention provides a dual-pressure liquid hydrogen refueling station system, which is further described in detail below with reference to the accompanying drawings.

[0040] like Figure 1 The present invention disclosed herein discloses a dual-pressure liquid hydrogen refueling station system, comprising:

[0041] The station includes a liquid hydrogen storage tank 1, a cryogenic pump 2, a mass flow distributor 5, a heat exchanger 6, a constant volume temperature and pressure boosting device, a 70MPa hydrogen distributor 19, a gasification temperature raising device, and a 35MPa hydrogen distributor 25.

[0042] The constant volume temperature increasing and pressurizing device includes a hot pressurizing tank 10, a medium pressure hydrogen storage tank 13 and a high pressure hydrogen storage tank 16 connected in parallel, the hot pressurizing tank 10 is provided with a first electric heater 8, a fourth control valve 9 and a fifth control valve 11 are provided at the input end and the output end of the hot pressurizing tank 10 respectively, a sixth control valve 14 and a seventh control valve 12 are provided at the input end and the output end of the medium pressure hydrogen storage tank 13 respectively, and an eighth control valve 17 and a ninth control valve 15 are provided at the input end and the output end of the high pressure hydrogen storage tank 16 respectively; and the input ends of the hot pressurizing tank 10, the medium pressure hydrogen storage tank 13 and the high pressure hydrogen storage tank 16 connected in parallel intersect at a first intersection 26 through a pipeline, and the output ends of the hot pressurizing tank 10, the medium pressure hydrogen storage tank 13 and the high pressure hydrogen storage tank 16 connected in parallel intersect at a second intersection 27 through a pipeline;

[0043] The gasification and heating device includes an air heat exchanger 20, a second electric heater 21 and a mixer 23 connected in series through a pipeline, and an eleventh control valve 22 is provided between the second electric heater 21 and the mixer 23;

[0044] The station liquid hydrogen storage tank 1, the cryogenic pump 2, the first control valve 3 and the mass flow distributor 5 are sequentially connected in series through pipelines;

[0045] The first output end of the mass flow distributor 5 is connected to the cold side of the heat exchanger 6, the third control valve 7, and the first intersection 26 in sequence through a pipeline, forming an input path of the heat exchanger 6; the second intersection 27 is connected to the hot side of the heat exchanger 6, the tenth control valve 18, and the 70 MPa hydrogen distributor 19 in sequence through a pipeline, forming an output path of the heat exchanger 6;

[0046] The second output end of the mass flow distributor 5 is connected in series with the gasification and temperature raising device, the twelfth control valve 24 and the 35 MPa hydrogen distributor 25 through a pipeline.

[0047] The mass flow distributor 5 distributes hydrogen of different mass flow rates in two directions to meet the hydrogen mass flow requirements of each pipeline.

[0048] In this embodiment, the low pressure threshold is 35 MPa, the medium pressure threshold is 67 MPa, and the low pressure threshold is 90 MPa. The dual-pressure liquid hydrogen refueling station system supports refueling of two types of on-board hydrogen storage tanks, 35 MPa and 70 MPa. The specific method of use includes the following steps:

[0049] (1) Refueling preparation process

[0050] S1: Open the first control valve 3 to transfer the liquid hydrogen at a temperature of -253°C and a pressure of 35 MPa stored in the station liquid hydrogen storage tank 1 to the mass flow distributor 5 through the cryogenic pump 2;

[0051] S2: The mass flow distributor 5 injects a fixed amount of liquid hydrogen into the cold side of the heat exchanger 6, opens the third control valve 7 and the fourth control valve 9, closes the fifth control valve 11, the sixth control valve 14, the seventh control valve 12, the eighth control valve 17 and the ninth control valve 15, and injects all the fixed amount of liquid hydrogen into the autoclave 10;

[0052] S3: closing the third control valve 7 and the fourth control valve 9, and turning on the first electric heater 8 to gasify the liquid hydrogen in the autoclave 10, thereby achieving constant volume, temperature, and pressure increase;

[0053] S4: When the pressure in the autoclave 10 is greater than or equal to the low-pressure threshold, the fourth control valve 9 and the sixth control valve 14 are opened to fill the medium-pressure hydrogen storage tank 13, and the first electric heater 8 is continued to be turned on to further increase the pressure in the autoclave 10;

[0054] S5: When the pressure in the autoclave 10 is greater than or equal to the medium pressure threshold, the sixth control valve 14 is closed, the eighth control valve 17 is opened, the high-pressure hydrogen storage tank 16 is filled, and the first electric heater 8 is continued to be turned on to further increase the pressure in the autoclave 10;

[0055] S6: When the pressure in the autoclave 10 is greater than or equal to the high-pressure threshold, the first electric heater 8, the fourth control valve 9 and the eighth control valve 17 are closed to complete the filling preparation;

[0056] In this embodiment, the station liquid hydrogen storage tank 1 uses the cryogenic pump 2 to transfer liquid hydrogen at a temperature of -253°C and a pressure of about 35 MPa through the heat exchanger 6 for heat exchange, and then injects it into the autoclave 10. The third control valve 7 and the fourth control valve 9 are opened, and the fifth control valve 11, the sixth control valve 14, the seventh control valve 12, the eighth control valve 17 and the ninth control valve 15 are closed. The mass flow distributor 5 only distributes a certain amount of liquid hydrogen into the autoclave 10. When a certain mass is reached, the third control valve 7 is closed and the liquid hydrogen is discharged. Turn on the first electric heater 8 to gasify the liquid hydrogen to achieve constant volume and temperature increase. The autoclave is electrically heated to gasify the liquid hydrogen and the temperature reaches about -160°C. When the pressure reaches 35MPa, open the sixth control valve 14 to start filling the medium-pressure hydrogen storage tank 13. When the pressure reaches 67MPa, close the sixth control valve 14 and open the eighth control valve 17 to start filling the high-pressure hydrogen storage tank 16. When the pressure reaches 90MPa, close the eighth control valve 17. After completing the above process, you can start preparing to fill the on-board hydrogen storage tank.

[0057] In this embodiment, a cryogenic pump 2 (i.e., a low-pressure liquid hydrogen pump) is used to inject liquid hydrogen into an autoclave 10 through a heat exchanger 6. Constant-volume heating is used to vaporize and pressurize the liquid hydrogen within the autoclave 10. Different pipelines are used to distribute the low-temperature hydrogen and the vaporized and heated hydrogen to quickly reach the target filling temperature. Compared to traditional liquid hydrogen pressurization and vaporization technology, this eliminates the need for high-pressure liquid hydrogen pumps and reduces the outlet pressure of the liquid hydrogen pump. This technology offers advantages such as low energy consumption, low initial investment costs, and a short pre-cooling system feedback time. Furthermore, it boasts filling capacities of 70 MPa and 35 MPa, meeting the needs of multiple hydrogen refueling scenarios.

[0058] In this embodiment, when the gaseous hydrogen in the autoclave 10, the medium-pressure hydrogen storage tank 13 and the high-pressure hydrogen storage tank 16 does not meet the hydrogenation pressure requirement, the mass flow distributor 5 can be used to distribute a certain amount of liquid hydrogen into the autoclave 10, and the autoclave 10, the medium-pressure hydrogen storage tank 13 and the high-pressure hydrogen storage tank 16 are circulated and filled again until the pressure requirement for continuous filling of the on-board hydrogen storage tank is reached, and the low-pressure gaseous hydrogen in the hydrogen storage tank can be pressurized in the next hydrogenation cycle, which can effectively improve the problem of residual hydrogen in the hydrogen storage tank.

[0059] (2) Filling the 70MPa onboard hydrogen storage tank

[0060] S7: When filling a 70MPa-class on-board hydrogen storage tank, by adjusting the opening and closing of the fifth control valve 11, the seventh control valve 12, and the ninth control valve 15, a tank body with a hydrogen pressure greater than or equal to the medium pressure threshold is selected from the autoclave 10, the medium-pressure hydrogen storage tank 13, and the high-pressure hydrogen storage tank 16, and the hydrogen in the selected tank body is injected into the hot side of the heat exchanger 6 through a pipeline. When the hydrogen temperature in the hot side of the heat exchanger 6 is less than or equal to -40°C, the tenth control valve 18 is opened to inject the hydrogen into the 70MPa hydrogen distributor 19, thereby filling the 70MPa-class on-board hydrogen storage tank with hydrogen;

[0061] S8: When the gaseous hydrogen pressure in the tank selected in S7 is less than the medium pressure threshold, S7 is repeated to select a tank with a gaseous hydrogen pressure greater than or equal to the medium pressure threshold again, and the 70MPa-level on-board hydrogen storage tank is filled with gaseous hydrogen; when the gaseous hydrogen pressure in the autoclave 10, the medium-pressure hydrogen storage tank 13, and the high-pressure hydrogen storage tank 16 are all less than the medium pressure threshold, S1-S6 are repeated to complete the filling preparation again;

[0062] In this embodiment, when the hydrogen fuel cell vehicle arrives at the hydrogen refueling station, the autoclave 10 is first used to start filling the on-board hydrogen storage tank. At this time, the fifth control valve 11 is opened to flow through the heat exchanger 6 to make the hydrogen reach -40°C, and then enter the 70MPa hydrogen distributor 19 to fill the on-board hydrogen storage tank; when the pressure in the autoclave 10 is not sufficient to fill the on-board hydrogen storage tank, that is, when the hydrogen pressure in the tank is less than the medium pressure threshold, the medium pressure hydrogen storage tank 13 is used, and the fifth control valve is closed at this time. 11 Open the seventh control valve 12 so that the temperature of the hydrogen flowing through the heat exchanger 6 is -40°C, and the onboard hydrogen storage tank continues to be filled through the 70MPa distributor. When the pressure in the medium-pressure hydrogen storage tank 13 is not sufficient to fill the onboard hydrogen storage tank, the high-pressure hydrogen storage tank 16 is used. At this time, the seventh control valve 12 is closed and the ninth control valve 15 is opened. The temperature of the hydrogen flowing through the heat exchanger 6 is -40°C, and the onboard hydrogen storage tank continues to be filled through the 70MPa distributor until the onboard hydrogen storage tank reaches the target filling degree. When the pressure in the hydrogen storage tank is low, the circulating liquid hydrogen is constant volume, heated and pressurized.

[0063] In this embodiment, when filling the on-board hydrogen storage tank, hydrogen is discharged sequentially from the autoclave 10, the medium-pressure hydrogen storage tank 13, and the high-pressure hydrogen storage tank 16, and then enters the distributor after being pre-cooled by the heat exchanger, thereby achieving a filling capacity of 70 MPa.

[0064] In an optional embodiment, to improve safety, when the pressure in the on-board hydrogen storage tank is low, the medium-pressure hydrogen storage tank 13 is preferentially used to fill the 70MPa-level on-board hydrogen storage tank, so that the air pressure in the on-board hydrogen storage tank gradually increases. When the pressure in the on-board hydrogen storage tank increases, the high-pressure hydrogen storage tank 16 is used to fill the 70MPa-level on-board hydrogen storage tank through valve control, thereby increasing the filling speed.

[0065] (3) Filling the 35MPa onboard hydrogen storage tank

[0066] S9: When filling the 35MPa-class on-board hydrogen storage tank, the mass flow distributor 5 injects a fixed amount of liquid hydrogen into the air heat exchanger 20 for gasification and temperature increase to form gaseous hydrogen; the gaseous hydrogen enters the second electric heater 21 through the pipeline for further heating, and the eleventh control valve 22 is opened to allow the gaseous hydrogen to enter the mixer 23; when the temperature of the gaseous hydrogen in the mixer 23 is less than or equal to -40°C, the twelfth control valve 24 is opened to inject the gaseous hydrogen into the 35MPa hydrogen distributor 25, thereby filling the 35MPa-class on-board hydrogen storage tank;

[0067] S10: When the mass flow distributor 5 is insufficient in liquid hydrogen, S1 is repeatedly executed to replenish the mass flow distributor 5 with liquid hydrogen.

[0068] In this embodiment, when it is necessary to fill the 35MPa-level on-board hydrogen storage tank: the cryogenic pump 2 pumps the liquid hydrogen directly to the air heat exchanger 20 through the pipeline, and then enters the second electric heater 21 for further heating after vaporization, and then reaches the mixer 23. When the hydrogen temperature in the mixer 23 reaches -40°C, it passes through the 35MPa hydrogen distributor 25 to fill the on-board hydrogen storage tank.

[0069] In an optional embodiment, while filling the 35MPa-level on-board hydrogen storage tank, the mass flow distributor 5 is used to distribute part of the liquid hydrogen to the autoclave 10 that needs to be replenished with liquid hydrogen, and the constant volume heating, gasification and pressurization are circulated to simultaneously meet the hydrogenation needs of multiple scenarios, reduce the long standby time of the pre-cooling system, and improve the filling efficiency.

[0070] In an optional embodiment, a cold storage device is provided in the heat exchanger 6 , and the first control valve 3 , the second control valve 4 and the mixer 23 are sequentially connected in series through pipelines.

[0071] After the mass flow distributor 5 injects a fixed amount of liquid hydrogen into the cold side of the heat exchanger 6 in S2 and before all the fixed amount of liquid hydrogen is injected into the autoclave 10, the process further includes: storing the cold energy of the liquid hydrogen in the heat exchanger 6 in the cold storage device;

[0072] When the gaseous hydrogen in the selected tank is injected into the hot side of the heat exchanger 6 through the pipeline in S7, the cold storage device of the heat exchanger 6 is used to cool the gaseous hydrogen on the hot side of the heat exchanger 6.

[0073] In this embodiment, a cryogenic pump 2 is used to circulate liquid hydrogen through a heat exchanger 6 with a cold storage device, and after storing a portion of the cold energy of the liquid hydrogen, it is injected into the autoclave 10. When the gaseous hydrogen in the autoclave 10, the medium-pressure hydrogen storage tank 13, and the high-pressure hydrogen storage tank 16 flows through the heat exchanger 6 with a cold storage device, the cold energy stored in the cold storage device is used to accelerate the pre-cooling process, so that the temperature of the gaseous hydrogen reaches -40°C more quickly.

[0074] In this embodiment, a portion of the liquid hydrogen cooling capacity is first stored using a heat exchanger 6 with cold storage, and then enters the autoclave 10 to heat and increase the temperature of the hydrogen to achieve constant volume and pressure boosting. The low-pressure hydrogen after each hydrogenation can be circulated and pressurized using a cryogenic pump 2, greatly reducing the waste of hydrogen. The hydrogen refueling station system proposed in this embodiment can have a hydrogenation capacity of 70MPa without a high-pressure compressor, while fully utilizing the cooling capacity of the liquid hydrogen, greatly reducing the operating energy consumption of the entire station, and can effectively reduce the long standby time of the pre-cooling system, thereby improving the refueling efficiency.

[0075] The first control valve 3 , the second control valve 4 and the mixer 23 are sequentially connected in series through pipelines.

[0076] When the gaseous hydrogen in S9 enters the mixer 23 , the second control valve 4 is opened to inject liquid hydrogen into the mixer 23 through the pipeline to cool the gaseous hydrogen in the mixer 23 .

[0077] In this embodiment, when it is necessary to refuel a 35MPa hydrogen fuel cell vehicle, the cryogenic pump 2 is used to divide the hydrogen into two paths, one of which flows through the air heat exchanger 20 for heating and gasification, and then flows into the second electric heater 21 for secondary heating, and the temperature reaches about 290K. The other path uses the cryogenic pump 2 to pump low-temperature liquid hydrogen of the same pressure into the pipeline and mix it with hydrogen of about 290k at the mixer 23. The hydrogen mass flow rates in the two paths are adjusted by the eleventh control valve 22 and the second control valve 4 so that the hydrogen temperature at the mixer 32 reaches -40°C faster. Finally, the hydrogen fuel cell vehicle is refueled through the 35MPa hydrogen distributor, thereby achieving the purpose of directly refueling the on-board hydrogen storage tank, which can further reduce the response time of the precooling system when there is a need for hydrogen refueling, further improve the response speed of hydrogen refueling demand, and improve the refueling efficiency.

[0078] In an optional embodiment, the heat exchanger 6 is provided with a cold storage device, which is connected in series with the first control valve (3), the second control valve (4) and the mixer (23) through pipelines and can be implemented separately, which will not be described in detail here.

Claims

1. A method for using a dual-pressure liquid hydrogen refueling station system, characterized in that: The steps include: S1: Open the first control valve (3) to transfer the liquid hydrogen stored in the station liquid hydrogen storage tank (1) at a temperature of -253°C and a pressure of 35 MPa to the mass flow distributor (5) through the cryogenic pump (2); S2: The mass flow distributor (5) injects a fixed amount of liquid hydrogen into the cold side of the heat exchanger (6), opens the third control valve (7) and the fourth control valve (9), closes the fifth control valve (11), the sixth control valve (14), the seventh control valve (12), the eighth control valve (17) and the ninth control valve (15), and injects all the fixed amount of liquid hydrogen into the autoclave (10); S3: closing the third control valve (7) and the fourth control valve (9), and turning on the first electric heater (8) to gasify the liquid hydrogen in the autoclave (10) to achieve constant volume, temperature, and pressure increase; S4: When the pressure in the autoclave (10) is greater than or equal to the low-pressure threshold, the fourth control valve (9) and the sixth control valve (14) are opened to fill the medium-pressure hydrogen storage tank (13), and the first electric heater (8) is continued to be opened to increase the pressure in the autoclave (10); S5: When the pressure in the autoclave (10) is greater than or equal to the medium pressure threshold, the sixth control valve (14) is closed, the eighth control valve (17) is opened, the high-pressure hydrogen storage tank (16) is filled, and the first electric heater (8) is continued to be opened to increase the pressure in the autoclave (10); S6: When the pressure in the autoclave (10) is greater than or equal to the high-pressure threshold, the first electric heater (8), the fourth control valve (9) and the eighth control valve (17) are closed to complete the filling preparation; S7: When filling a 70MPa-class on-board hydrogen storage tank, by adjusting the opening and closing of the fifth control valve (11), the seventh control valve (12) and the ninth control valve (15), a tank body with a gas hydrogen pressure greater than or equal to the medium pressure threshold is selected from the autoclave (10), the medium pressure hydrogen storage tank (13) and the high pressure hydrogen storage tank (16), and the gas hydrogen in the selected tank body is injected into the hot side of the heat exchanger (6) through a pipeline. When the gas hydrogen temperature in the hot side of the heat exchanger (6) is less than or equal to -40°C, the tenth control valve (18) is opened to inject the gas hydrogen into the 70MPa hydrogen distributor (19), thereby filling the 70MPa-class on-board hydrogen storage tank with gas hydrogen; S8: When the gaseous hydrogen pressure in the tank selected in S7 is less than the medium pressure threshold, S7 is repeated to select a tank whose gaseous hydrogen pressure is greater than or equal to the medium pressure threshold again, and the 70MPa-level on-board hydrogen storage tank is filled with gaseous hydrogen; when the gaseous hydrogen pressure in the autoclave (10), the medium pressure hydrogen storage tank (13) and the high pressure hydrogen storage tank (16) are all less than the medium pressure threshold, S1-S6 are repeated to complete the filling preparation again; S9: When filling the 35MPa-class on-board hydrogen storage tank, the mass flow distributor (5) injects a fixed amount of liquid hydrogen into the air heat exchanger (20) for gasification and temperature increase to form gaseous hydrogen; the gaseous hydrogen enters the second electric heater (21) through the pipeline for further heating, and the eleventh control valve (22) is opened to allow the gaseous hydrogen to enter the mixer (23); when the temperature of the gaseous hydrogen in the mixer (23) is less than or equal to -40°C, the twelfth control valve (24) is opened to inject the gaseous hydrogen into the 35MPa hydrogen distributor (25), thereby filling the 35MPa-class on-board hydrogen storage tank; S10: When the liquid hydrogen in the mass flow distributor (5) is insufficient, repeating S1 to replenish the liquid hydrogen for the mass flow distributor (5); A fourth control valve (9) and a fifth control valve (11) are respectively provided at the input end and the output end of the autoclave (10); a sixth control valve (14) and a seventh control valve (12) are respectively provided at the input end and the output end of the medium-pressure hydrogen storage tank (13); and an eighth control valve (17) and a ninth control valve (15) are respectively provided at the input end and the output end of the high-pressure hydrogen storage tank (16); The gasification temperature raising device is connected to the eleventh control valve (22) via the second electric heater (21); The mass flow distributor (5) is connected to the third control valve (7) and the tenth control valve (18) via the heat exchanger (6), and is connected to the twelfth control valve (24) via the gasification temperature raising device; The first control valve (3), the second control valve (4) and the mixer (23) are sequentially connected in series via a pipeline.

2. The method for using the dual-pressure liquid hydrogen refueling station system according to claim 1, characterized in that: After the mass flow distributor (5) injects a fixed amount of liquid hydrogen into the cold side of the heat exchanger (6) in S2, and before all the fixed amount of liquid hydrogen is injected into the autoclave (10), the method further includes: storing the cold energy of the liquid hydrogen in the heat exchanger (6) in a cold storage device; When the gaseous hydrogen in the selected tank is injected into the hot side of the heat exchanger (6) through the pipeline in S7, the cold storage device of the heat exchanger (6) is used to cool the gaseous hydrogen on the hot side of the heat exchanger (6).

3. The method for using the dual-pressure liquid hydrogen refueling station system according to claim 1, characterized in that: The low pressure threshold is 35 MPa, the medium pressure threshold is 67 MPa, and the low pressure threshold is 90 MPa.

4. The method for using the dual-pressure liquid hydrogen refueling station system according to claim 1, characterized in that: When the gaseous hydrogen in S9 enters the mixer (23), the second control valve (4) is opened to inject liquid hydrogen into the mixer (23) through the pipeline to cool the gaseous hydrogen in the mixer (23).

5. A dual-pressure liquid hydrogen refueling station system, using the method for using a dual-pressure liquid hydrogen refueling station system as claimed in claim 1, characterized in that: include: The station comprises a liquid hydrogen storage tank (1), a cryogenic pump (2), a mass flow distributor (5), a heat exchanger (6), a constant volume temperature raising and pressurizing device, a 70 MPa hydrogen distributor (19), a gasification temperature raising device and a 35 MPa hydrogen distributor (25), characterized in that: The constant volume temperature increasing and pressurizing device comprises a parallel connected autoclave (10), a medium pressure hydrogen storage tank (13) and a high pressure hydrogen storage tank (16), wherein the autoclave (10) is provided with a first electric heater (8); the input ends of the parallel connected autoclave (10), the medium pressure hydrogen storage tank (13) and the high pressure hydrogen storage tank (16) intersect at a first intersection (26) through a pipeline, and the output ends of the parallel connected autoclave (10), the medium pressure hydrogen storage tank (13) and the high pressure hydrogen storage tank (16) intersect at a second intersection (27) through a pipeline; The gasification and temperature-raising device comprises an air heat exchanger (20), a second electric heater (21), and a mixer (23) connected in series via a pipeline, and an eleventh control valve (22) is provided between the second electric heater (21) and the mixer (23); The station liquid hydrogen storage tank (1), the cryogenic pump (2), the first control valve (3) and the mass flow distributor (5) are sequentially connected in series through a pipeline; The first output end of the mass flow distributor (5) is connected to the cold side of the heat exchanger (6), the third control valve (7), and the first intersection (26) in sequence through a pipeline, forming an input path of the heat exchanger (6); the second intersection (27) is connected to the hot side of the heat exchanger (6), the tenth control valve (18), and the 70MPa hydrogen distributor (19) in sequence through a pipeline, forming an output path of the heat exchanger (6); The second output end of the mass flow distributor (5) is sequentially connected in series with the gasification temperature raising device, the twelfth control valve (24) and the 35MPa hydrogen distributor (25) through a pipeline.

6. The dual-pressure liquid hydrogen refueling station system according to claim 5, characterized in that: A cold storage device is provided in the heat exchanger (6).

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