A system and method for hydrogen liquefaction with potential recovery

Abstract

The present disclosure relates to a hydrogen liquefaction system and method capable of recovering energy, which comprises a pressure control unit, a precooling and rewarming unit, a liquid nitrogen cooling unit, a hydrogen liquefaction unit and a comprehensive heat exchange unit. The system of the present disclosure can maximize the recovery and utilization of energy in the hydrogen liquefaction process, thereby improving the utilization rate of energy.

Description

Technical Field

[0001] This application relates to the field of hydrogen liquefaction, and more specifically, to a system and method for the liquefaction of hydrogen with the potential for quantity recovery. Background Technology

[0002] With the transformation of the global energy structure and the increasing demand for clean energy, hydrogen energy, as an efficient and clean energy carrier, has received widespread attention for its development and utilization. Hydrogen energy boasts advantages such as high energy density, renewability, and environmental friendliness, and is considered an important component of future energy systems. In the hydrogen energy industry chain, the liquefaction, storage, transportation, and utilization of hydrogen are key links, and liquid hydrogen, due to its high density by weight and volume, as well as its purity, has become one of the important forms of hydrogen energy application.

[0003] Hydrogen liquefaction is the process of converting gaseous hydrogen into liquid hydrogen, which requires extremely low temperatures, typically around -253°C. At room temperature, hydrogen is usually an equilibrium mixture of 75% orthohydrogen and 25% parahydrogen. However, at low temperatures, orthohydrogen spontaneously converts to parahydrogen, releasing heat of conversion. This process is particularly important in liquid hydrogen systems because, if left uncontrolled, the natural conversion of orthohydrogen to parahydrogen can lead to liquid hydrogen evaporation and increased tank pressure, potentially causing safety hazards.

[0004] In existing hydrogen liquefaction processes, the 80K temperature zone typically includes a raw material gas path hydrogen cryogenic adsorber group and a circulating gas path hydrogen cryogenic adsorber. The 80K raw material gas path cryogenic adsorber group consists of two hydrogen cryogenic adsorbers connected in parallel, one in use and one on standby. While one is regenerating, the other can continue to operate normally without affecting the continuous operation of the hydrogen liquefaction unit. After operating for a period of time, the cryogenic adsorber is generally regenerated offline. During the regeneration process, nitrogen or hydrogen is typically used to purge the adsorber and remove impurity gases.

[0005] In liquid nitrogen cooling units, nitrogen is typically released, which involves pressure and low temperature, resulting in energy waste. Currently, hydrogen production involves not only efficient cooling technology, but also energy efficiency and safety. Although liquid hydrogen production technology has made some progress, there are still problems such as high energy consumption and complex equipment that need to be solved. Summary of the Invention

[0006] The purpose of this disclosure is to provide a system and method for hydrogen liquefaction that can recover a significant amount of energy. The system disclosed herein can maximize the energy recovery and utilization during the hydrogen liquefaction process, thereby improving energy efficiency.

[0007] To achieve the above objectives, the first aspect of this disclosure provides an energy-recovery hydrogen liquefaction system, which includes: a pressure control unit, a precooling and reheating unit, a liquid nitrogen cooling unit, a hydrogen liquefaction unit, and a comprehensive heat exchange unit; The pressure control unit is used to control system pressure and maintain system pressure stability. The precooling and reheating unit is used to heat and reheat the system during the system start-up phase to remove residual liquid hydrogen from the system, and / or to precool the raw material hydrogen when the raw material hydrogen temperature is high. The liquid nitrogen cooling unit is used to provide cooling for hydrogen liquefaction in the hydrogen liquefaction unit. The hydrogen liquefaction unit is used to liquefy gaseous hydrogen. The integrated heat exchange unit recovers the cold or heat from the hydrogen liquefaction unit and the precooling and reheating unit, and provides cold and / or heat to the hydrogen liquefaction unit and the precooling and reheating unit. It is also used to recover the cold from the hydrogen liquefaction unit.

[0008] Optionally, the pressure control unit includes a first compressor unit; The hydrogen liquefaction unit includes a first hydrogen cooler group, a second hydrogen cooler group, a purifier, a third hydrogen cooler group, a first and second hydrogen converter, a fourth hydrogen cooler group, a second and second hydrogen converter, a compressor cooler, a throttle valve, a hydrogen storage tank, and a first expander unit; the first and second hydrogen converter is disposed within the third hydrogen cooler group, and the second and second hydrogen converter is disposed within the fourth hydrogen cooler group; the compressor cooler is used to cool the compressor; The first hydrogen cooler assembly includes a first raw material hydrogen channel, a first refrigerated hydrogen channel, a second refrigerated hydrogen channel, a third refrigerated hydrogen channel, and a first liquid nitrogen refrigeration channel; The second hydrogen cooler assembly includes a second raw material hydrogen channel, a fourth refrigerated hydrogen channel, and a second liquid nitrogen refrigeration channel; The third hydrogen cooler assembly includes a third raw material hydrogen channel, a fifth refrigerated hydrogen channel, a sixth refrigerated hydrogen channel, and a seventh refrigerated hydrogen channel. The fourth hydrogen cooler assembly includes a fourth raw material hydrogen channel and an eighth cooling hydrogen channel. The outlet of the precooling and reheating unit is fluidly connected to the inlet of the first raw material hydrogen channel of the first hydrogen cooler group; the outlet of the first raw material hydrogen channel of the first hydrogen cooler group is fluidly connected to the inlet of the second raw material hydrogen channel of the second hydrogen cooler group; the outlet of the second raw material hydrogen channel of the second hydrogen cooler group is fluidly connected to the inlet of the purifier; the outlet of the purifier is fluidly connected to the inlet of the third raw material hydrogen channel of the third hydrogen cooler group; and the outlet of the raw material hydrogen channel of the third hydrogen cooler group is fluidly connected to the inlet of the third raw material hydrogen channel of the fourth hydrogen cooler group. The outlet of the precooling and reheating unit is also fluidly connected to the inlet of the first compressor unit. The outlet of the first compressor unit is fluidly connected to the inlet of the first refrigerant hydrogen channel of the first hydrogen cooler unit. The outlet of the first refrigerant hydrogen channel of the first hydrogen cooler unit is fluidly connected to the inlet of the fourth refrigerant hydrogen channel of the second hydrogen cooler unit. The outlet of the fourth refrigerant hydrogen channel of the second hydrogen cooler unit is fluidly connected to the inlet of the fifth refrigerant channel of the third hydrogen cooler unit. The outlet of the fifth refrigerant channel of the third hydrogen cooler unit is fluidly connected to the inlet of the first expander unit through a first pipeline. The outlet of the first expander unit is fluidly connected to the inlet of the sixth refrigerant hydrogen channel of the third hydrogen cooler unit. The outlet of the sixth refrigerant hydrogen channel of the third hydrogen cooler unit is fluidly connected to the inlet of the second refrigerant channel of the first hydrogen cooler unit. The outlet of the second refrigerant channel of the first hydrogen cooler unit is fluidly connected to the inlet of the first compressor unit. The outlet of the fifth refrigeration channel of the third hydrogen cooler group is also fluidly connected to the hydrogen storage tank through a second pipeline. The throttle valve is installed on the second pipeline. The liquid outlet of the hydrogen storage tank is fluidly connected to the inlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group. The outlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group is fluidly connected to the inlet of the hydrogen storage tank. The gas outlet of the hydrogen storage tank is fluidly connected to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group. The outlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group is fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group. The outlet of the third refrigeration hydrogen channel of the first hydrogen cooler group is fluidly connected to the inlet of the first compressor group. The integrated heat exchange unit includes an expander and a cold storage module, as well as a heat pump and a thermal storage module; The refrigerant inlet of the precooling and reheating unit and the refrigerant inlet of the compressor cooler are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module, and the refrigerant outlet of the precooling and reheating unit and the refrigerant outlet of the compressor cooler are each independently fluidly connected to the refrigerant inlet of the expander and cold storage module. The heat exchange medium inlet of the precooling and reheating unit and the heat exchange medium inlet of the purifier are each independently fluidly connected to the heat exchange medium outlet of the heat pump and the heat storage module, and the heat exchange medium outlet of the precooling and reheating unit and the heat exchange medium outlet of the purifier are each independently fluidly connected to the heat exchange medium inlet of the heat pump and the heat storage module.

[0009] Optionally, the integrated heat exchange unit further includes a temperature sensor, a first heat exchanger, a first valve, and a refrigerant inlet pipeline; the refrigerant inlet pipeline includes a first refrigerant inlet pipeline main line, a first refrigerant inlet pipeline branch line, and a second refrigerant inlet pipeline branch line, and the first valve is installed on the second refrigerant inlet pipeline branch line; The outlet of the first refrigerant inlet pipeline branch is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the outlet of the second refrigerant inlet pipeline branch is fluidly connected to the inlet of the heat exchange medium to be exchanged in the first heat exchanger; the outlet of the heat exchange medium to be exchanged in the first heat exchanger is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the inlet of the heat exchange medium of the first heat exchanger is fluidly connected to the outlet of the heat exchange medium of the heat pump and the heat storage module; and the outlet of the heat exchange medium of the first heat exchanger is fluidly connected to the inlet of the heat exchange medium of the heat pump and the heat storage module. Preferably, the integrated heat exchange unit further includes a second heat exchanger, a first heat exchange medium pipeline, and a second heat exchange medium pipeline; The outlet of the first heat exchange medium pipeline is in fluid communication with the heat exchange medium inlet of the heat pump and the heat storage module; the inlet of the first heat exchange medium pipeline is in fluid communication with the heat exchange medium outlet of the second heat exchanger; the outlet of the second heat exchange medium pipeline is in flow communication with the heat exchange medium inlet of the second heat exchanger; and the inlet of the second heat exchange medium pipeline is in fluid communication with the heat exchange medium outlet of the heat pump and the heat storage module. Preferably, the system includes multiple integrated heat exchange units; the multiple integrated heat exchange units are arranged in parallel or in series.

[0010] Optionally, the liquid nitrogen cooling unit includes a liquid nitrogen storage tank, a liquid nitrogen generator, and a second expander unit; The liquid outlet of the liquid nitrogen storage tank is in fluid communication with the inlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group; the outlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group is in fluid communication with the inlet of the liquid nitrogen storage tank; the gas outlet of the liquid nitrogen storage tank is in fluid communication with the inlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group; the outlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group is in fluid communication with the inlet of the second expander group; the outlet of the second expander group is in fluid communication with the refrigerant inlet of the expander and cold storage module; the refrigerant outlet of the expander and cold storage module is in fluid communication with the inlet of the liquid nitrogen generator; and the outlet of the liquid nitrogen generator is in fluid communication with the inlet of the liquid nitrogen storage tank.

[0011] Optionally, the purifier includes a first purifier and a second purifier arranged in parallel, wherein the first purifier and the second purifier are each independently provided with one or more of activated carbon, fine-pored silica gel and molecular sieve.

[0012] Optionally, the system further includes an air compression unit, which includes a third compressor unit, a compressed gas storage tank, and a screw compressor; The outlet of the third compressor unit is connected to the inlet of the compressed gas storage tank, the outlet of the compressed gas storage tank is connected to the compressed gas inlet of the screw compressor, and the gas outlet of the screw compressor is connected to the gas inlet of the precooling and reheating unit.

[0013] Optionally, the system further includes a third hydrogen cooler assembly and a second neutral hydrogen converter; the second neutral hydrogen converter is disposed in the third hydrogen cooler assembly. The hydrogen outlet of the first compressor unit is in fluid communication with the inlet of the refrigerant hydrogen passage of the second hydrogen cooler unit, and the outlet of the refrigerant hydrogen passage of the second hydrogen cooler unit is in fluid communication with the inlet of the first expander unit and with the refrigerant inlet of the third hydrogen cooler unit.

[0014] The second aspect of this disclosure provides a method for hydrogen liquefaction using the system provided in the first aspect of this disclosure, the method comprising: introducing raw material hydrogen into the precooling and reheating unit for precooling, and introducing precooled hydrogen into the hydrogen liquefaction unit for hydrogen liquefaction; The integrated heat exchange unit recovers the cold and / or heat from the hydrogen liquefaction unit and the precooling and reheating unit, and provides cold and / or heat to the hydrogen liquefaction unit and the precooling and reheating unit, and / or recovers the cold from the hydrogen liquefaction unit.

[0015] Optionally, the integrated heat exchange unit includes an expander and a cold storage module, as well as a heat pump and a thermal storage module; The refrigerant inlet of the precooling and reheating unit and the refrigerant inlet of the compressor cooler are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module, and the refrigerant outlet of the precooling and reheating unit and the refrigerant outlet of the compressor cooler are each independently fluidly connected to the refrigerant inlet of the expander and cold storage module. The heat exchange medium inlet of the precooling and reheating unit and the heat exchange medium inlet of the purifier are each independently fluidly connected to the heat exchange medium outlet of the heat pump and the heat storage module, and the heat exchange medium outlet of the precooling and reheating unit and the heat exchange medium outlet of the purifier are each independently fluidly connected to the heat exchange medium inlet of the heat pump and the heat storage module. The method includes: introducing the refrigerant from the expander and cold storage module of the integrated heat exchange unit into the precooling and reheating unit for heat exchange, and returning the refrigerant after heat exchange to the expander and cold storage module for heat recovery; The heat exchange medium of the heat pump and heat storage module of the integrated heat exchange unit is introduced into the purifier for heat exchange, and the heat exchange medium after heat exchange is returned to the heat pump and heat storage module for heat recovery.

[0016] Optionally, the integrated heat exchange unit further includes a temperature sensor, a first heat exchanger, a first valve, and a refrigerant inlet pipeline; the refrigerant inlet pipeline includes a first refrigerant inlet pipeline main line, a first refrigerant inlet pipeline branch line, and a second refrigerant inlet pipeline branch line, and the first valve is installed on the second refrigerant inlet pipeline branch line; The outlet of the first refrigerant inlet pipeline branch is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the outlet of the second refrigerant inlet pipeline branch is fluidly connected to the inlet of the heat exchange medium to be exchanged in the first heat exchanger; the outlet of the heat exchange medium to be exchanged in the first heat exchanger is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the inlet of the heat exchange medium of the first heat exchanger is fluidly connected to the outlet of the heat exchange medium of the heat pump and the heat storage module; and the outlet of the heat exchange medium of the first heat exchanger is fluidly connected to the inlet of the heat exchange medium of the heat pump and the heat storage module. The method further includes: when the temperature of the main line of the first refrigerant inlet pipeline detected by the temperature sensor is higher than the first preset temperature, opening the first valve and introducing part of the refrigerant from the branch line of the second refrigerant inlet pipeline into the first heat exchanger to exchange heat with the heat exchange medium from the heat pump and the heat storage module; The refrigerant after heat exchange is introduced into the expander and cold storage module through the branch of the first refrigerant inlet pipeline for cold energy recovery.

[0017] Optionally, the integrated heat exchange unit further includes a second heat exchanger, a first heat exchange medium pipeline, and a second heat exchange medium pipeline; The outlet of the first heat exchange medium pipeline is in fluid communication with the heat exchange medium inlet of the heat pump and the heat storage module; the inlet of the first heat exchange medium pipeline is in fluid communication with the heat exchange medium outlet of the second heat exchanger; the outlet of the second heat exchange medium pipeline is in flow communication with the heat exchange medium inlet of the second heat exchanger; and the inlet of the second heat exchange medium pipeline is in fluid communication with the heat exchange medium outlet of the heat pump and the heat storage module. The method further includes: when the initial operating temperature of the expander and the cold storage module is higher than the second preset temperature, introducing the heat exchange medium of the heat pump and the heat storage module into the second heat exchanger through the first heat exchange medium pipeline for heat exchange, and returning the heat exchange medium after heat exchange to the heat pump and the heat storage module through the second heat exchange medium pipeline.

[0018] Optionally, the pressure control unit includes a first compressor unit; The hydrogen liquefaction unit includes a first hydrogen cooler group, a second hydrogen cooler group, a purifier, a third hydrogen cooler group, a first and second hydrogen converter, a fourth hydrogen cooler group, a second and second hydrogen converter, a compressor cooler, a throttle valve, a hydrogen storage tank, and a first expander unit; the first and second hydrogen converter is disposed within the third hydrogen cooler group, and the second and second hydrogen converter is disposed within the fourth hydrogen cooler group; the compressor cooler is used to cool the compressor; The first hydrogen cooler assembly includes a first raw material hydrogen channel, a first refrigerated hydrogen channel, a second refrigerated hydrogen channel, a third refrigerated hydrogen channel, and a first liquid nitrogen refrigeration channel; The second hydrogen cooler assembly includes a second raw material hydrogen channel, a fourth refrigerated hydrogen channel, and a second liquid nitrogen refrigeration channel; The third hydrogen cooler assembly includes a third raw material hydrogen channel, a fifth refrigerated hydrogen channel, a sixth refrigerated hydrogen channel, and a seventh refrigerated hydrogen channel. The fourth hydrogen cooler assembly includes a fourth raw material hydrogen channel and an eighth cooling hydrogen channel. The outlet of the precooling and reheating unit is fluidly connected to the inlet of the first raw material hydrogen channel of the first hydrogen cooler group; the outlet of the first raw material hydrogen channel of the first hydrogen cooler group is fluidly connected to the inlet of the second raw material hydrogen channel of the second hydrogen cooler group; the outlet of the second raw material hydrogen channel of the second hydrogen cooler group is fluidly connected to the inlet of the purifier; the outlet of the purifier is fluidly connected to the inlet of the third raw material hydrogen channel of the third hydrogen cooler group; and the outlet of the third raw material hydrogen channel of the third hydrogen cooler group is fluidly connected to the inlet of the raw material hydrogen channel of the fourth hydrogen cooler group. The outlet of the precooling and reheating unit is also fluidly connected to the inlet of the first compressor unit. The outlet of the first compressor unit is fluidly connected to the inlet of the first refrigerant hydrogen channel of the first hydrogen cooler unit. The outlet of the first refrigerant hydrogen channel of the first hydrogen cooler unit is fluidly connected to the inlet of the fourth refrigerant hydrogen channel of the second hydrogen cooler unit. The outlet of the fourth refrigerant hydrogen channel of the second hydrogen cooler unit is fluidly connected to the inlet of the fifth refrigerant channel of the third hydrogen cooler unit. The outlet of the fifth refrigerant channel of the third hydrogen cooler unit is fluidly connected to the inlet of the first expander unit through a first pipeline. The outlet of the first expander unit is fluidly connected to the inlet of the sixth refrigerant hydrogen channel of the third hydrogen cooler unit. The outlet of the sixth refrigerant hydrogen channel of the third hydrogen cooler unit is fluidly connected to the inlet of the second refrigerant channel of the first hydrogen cooler unit. The outlet of the second refrigerant channel of the first hydrogen cooler unit is fluidly connected to the inlet of the first compressor unit. The outlet of the fifth refrigeration channel of the third hydrogen cooler group is also fluidly connected to the hydrogen storage tank through a second pipeline. The throttle valve is installed on the second pipeline. The liquid outlet of the hydrogen storage tank is fluidly connected to the inlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group. The outlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group is fluidly connected to the inlet of the hydrogen storage tank. The gas outlet of the hydrogen storage tank is fluidly connected to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group. The outlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group is fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group. The outlet of the third refrigeration hydrogen channel of the first hydrogen cooler group is fluidly connected to the inlet of the first compressor group. The process of introducing pre-cooled hydrogen into the hydrogen liquefaction unit for hydrogen liquefaction includes: The first portion of pre-cooled hydrogen is sequentially introduced into the first raw material hydrogen channel of the first hydrogen cooler group and the second raw material hydrogen channel of the second hydrogen cooler group for first cooling. The obtained first cooled hydrogen is then introduced into the purifier for purification to obtain purified hydrogen. The purified hydrogen is then introduced into the third raw material hydrogen channel of the third hydrogen cooler group for second cooling and a first positive and negative hydrogen conversion reaction to obtain second cooled hydrogen. The second cooled hydrogen is then introduced into the third raw material hydrogen channel of the fourth hydrogen cooler group for third cooling and a second positive and negative hydrogen conversion reaction to obtain liquefied hydrogen. The second portion of pre-cooled hydrogen is introduced into the first compressor unit for compression, and then sequentially introduced into the first refrigeration hydrogen channel of the first hydrogen cooler and the fourth refrigeration hydrogen channel of the second hydrogen cooler unit for cooling exchange. The first cooled hydrogen is introduced into the fifth refrigeration hydrogen channel of the third hydrogen cooler for cooling exchange with the raw material hydrogen. The resulting second cooled hydrogen is introduced into the first expander unit for expansion and cooling. The resulting cold hydrogen is sequentially introduced into the sixth refrigeration hydrogen channel of the third hydrogen cooler unit and the second refrigeration hydrogen channel of the first hydrogen cooler unit for cooling exchange. The cooled hydrogen is then reintroduced into the first compressor unit. The remaining portion of the second cooling hydrogen is throttled and cooled via a throttling valve on the second pipeline before being introduced into the hydrogen storage tank. The liquid hydrogen in the hydrogen storage tank is then introduced into the eighth cooling hydrogen channel of the fourth hydrogen cooler group for cooling. The cooled hydrogen is then introduced into the storage tank. The gaseous hydrogen in the storage tank is then sequentially introduced into the seventh cooling hydrogen channel of the third hydrogen cooler group and the third cooling hydrogen channel of the first hydrogen cooler group for cooling. The cooled hydrogen is then introduced into the first compressor group for compression.

[0019] Optionally, the liquid nitrogen cooling unit includes a liquid nitrogen storage tank, a liquid nitrogen generator, and a second expander unit. The liquid outlet of the liquid nitrogen storage tank is fluidly connected to the inlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group; the outlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group is fluidly connected to the inlet of the liquid nitrogen storage tank; the gas outlet of the liquid nitrogen storage tank is fluidly connected to the inlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group; the outlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group is fluidly connected to the inlet of the second expander group; the outlet of the second expander group is fluidly connected to the refrigerant inlet of the expander and cold storage module; the refrigerant outlet of the expander and cold storage module is fluidly connected to the inlet of the liquid nitrogen generator; and the outlet of the liquid nitrogen generator is fluidly connected to the inlet of the liquid nitrogen storage tank. The method further includes: introducing gaseous nitrogen from the liquid nitrogen storage tank into the first liquid nitrogen refrigeration channel of the first hydrogen cooler group for cooling exchange to obtain cooled nitrogen; introducing the cooled nitrogen into the second expander unit for expansion cooling; and introducing the obtained liquid nitrogen into the integrated heat exchange module to recover the cooling capacity. The liquid nitrogen in the liquid nitrogen storage tank is introduced into the second liquid nitrogen refrigeration channel of the second hydrogen cooler group for cooling, and the cooled nitrogen is introduced back into the liquid nitrogen storage tank.

[0020] Through the above technical solution, the hydrogen liquefaction system disclosed herein has an integrated heat exchange unit. By integrating this unit with the hydrogen liquefaction unit, the energy recovery and utilization during the hydrogen liquefaction process can be maximized, thereby improving energy utilization efficiency and reducing the energy consumption of the hydrogen liquefaction system.

[0021] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating one specific embodiment of the hydrogen liquefaction system disclosed herein.

[0023] Figure 2 This is a flowchart illustrating a specific implementation of the integrated heat exchange unit in the hydrogen liquefaction system disclosed herein.

[0024] Explanation of reference numerals in the attached figures 1. Pressure control unit; 2. Pre-cooling and reheating unit; 3. Liquid nitrogen cooling unit. 4. Hydrogen liquefaction unit; 5. Integrated heat exchange unit; 6. Air compression unit. 7. First hydrogen cooler group; 8. Second hydrogen cooler group; 9. Third hydrogen cooler group 10. Fourth Hydrogen Cooler Unit; 11. Purifier; 12. First Neutral Hydrogen Converter 13. Second neutral-to-parahydrogen converter; 14. Compressor cooler; 15. Throttling valve. 16. Hydrogen storage tank; 17. First expander unit; 18. First compressor unit 19. Liquid nitrogen storage tank; 20. Liquid nitrogen generator; 21. Second expander unit. 22. Third compressor unit; 23. Compressed gas storage tank; 24. Screw compressor 25. Expander and cold storage module; 26. Heat pump and thermal storage module; 27. Temperature sensor. 28. First heat exchanger; 29. ​​First valve; 30. Second heat exchanger 31. First heat exchange medium pipeline; 32. Second heat exchange medium pipeline Detailed Implementation The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0025] like Figure 1 As shown, the first aspect of this disclosure provides a hydrogen liquefaction system with potential energy recovery. The system includes: a pressure control unit 1, a pre-cooling and reheating unit 2, a liquid nitrogen cooling unit 3, a hydrogen liquefaction unit 4, and a comprehensive heat exchange unit 5. The pressure control unit 1 controls the system pressure and maintains a stable system pressure. The pre-cooling and reheating unit 2 heats and reheats the system during startup to remove residual liquid hydrogen, and / or pre-cools the feedstock hydrogen when its temperature is high. The liquid nitrogen cooling unit 3 provides cooling energy for hydrogen liquefaction in the hydrogen liquefaction unit. The hydrogen liquefaction unit 4 liquefies gaseous hydrogen. The comprehensive heat exchange unit 5 recovers the cooling or heating energy from the hydrogen liquefaction unit and the pre-cooling and reheating unit, and provides cooling and / or heating energy to the hydrogen liquefaction unit and the pre-cooling and reheating unit, and also recovers the cooling energy from the hydrogen liquefaction unit.

[0026] The hydrogen liquefaction system disclosed herein has an integrated heat exchange unit. By integrating this unit with the hydrogen liquefaction unit, the energy recovery and utilization during the hydrogen liquefaction process can be maximized, thereby improving energy utilization efficiency and reducing the energy consumption of the hydrogen liquefaction system.

[0027] According to this disclosure, heating and rewarming the system during the system startup phase to remove residual liquid hydrogen from the system can convert the liquid hydrogen remaining in the system into gaseous state and discharge it before the system is shut down for a long period of time, and also warm the equipment to room temperature in preparation for system startup.

[0028] In one specific embodiment, the precooling and rewarming unit can be used to heat the hydrogen in the system so that when the hydrogen liquefaction system is in the rewarming process, the hydrogen in the system is heated up to rewarm the system and the cryogenic liquid hydrogen in the system is quickly discharged.

[0029] In another specific embodiment, the precooling and reheating unit can be used to precool the feedstock hydrogen so as to precool the hydrogen gas at a high temperature under high ambient temperature conditions.

[0030] like Figure 2 As shown, in one specific embodiment of this disclosure, the pressure control unit 1 includes a first compressor group 18. Preferably, the first compressor group includes a first compressor and a second compressor arranged in series. The pressure control unit may also include a pressure gauge and a pressure regulating valve. The hydrogen liquefaction unit includes a first hydrogen cooler group 7, a second hydrogen cooler group 8, a purifier 11, a third hydrogen cooler group 9, a first neutral hydrogen converter 12, a fourth hydrogen cooler group 10, a second neutral hydrogen converter 13, a compressor cooler 14, a throttle valve 15, a hydrogen storage tank 16, and a first expander group 17. The first neutral hydrogen converter is disposed within the third hydrogen cooler group, and the second neutral hydrogen converter is disposed within the fourth hydrogen cooler group. The compressor cooler is used to cool the compressor. The first hydrogen cooler group 7 includes a first raw material hydrogen channel, a first refrigerated hydrogen channel, a second refrigerated hydrogen channel, a third refrigerated hydrogen channel, and a first liquid nitrogen refrigeration channel; the second hydrogen cooler group 8 includes a second raw material hydrogen channel, a fourth refrigerated hydrogen channel, and a second liquid nitrogen refrigeration channel; the third hydrogen cooler group 9 includes a third raw material hydrogen channel, a fifth refrigerated hydrogen channel, a sixth refrigerated hydrogen channel, and a seventh refrigerated hydrogen channel; the fourth hydrogen cooler group 10 includes a fourth raw material hydrogen channel and an eighth refrigerated hydrogen channel. The outlet of the precooling and reheating unit 2 is fluidly connected to the inlet of the first raw material hydrogen channel of the first hydrogen cooler group 7. The outlet of the first raw material hydrogen channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the second raw material hydrogen channel of the second hydrogen cooler group 8. The outlet of the second raw material hydrogen channel of the second hydrogen cooler group 8 is fluidly connected to the inlet of the purifier 11. The outlet of the purifier 11 is fluidly connected to the inlet of the third raw material hydrogen channel of the third hydrogen cooler group 9. The outlet of the third raw material hydrogen channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the raw material hydrogen channel of the fourth hydrogen cooler group 10. The outlet of the precooling and reheating unit 2 is also fluidly connected to the inlet of the first compressor unit 18. The outlet of the first compressor unit 18 is fluidly connected to the inlet of the first refrigerant hydrogen channel of the first hydrogen cooler group 7. The outlet of the first refrigerant hydrogen channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the fourth refrigerant hydrogen channel of the second hydrogen cooler group 8. The outlet of the fourth refrigerant hydrogen channel of the second hydrogen cooler group 8 is fluidly connected to the inlet of the fifth refrigerant channel of the third hydrogen cooler group 9. The outlet of the fifth refrigerant channel of the third hydrogen cooler group is fluidly connected to the inlet of the first expander unit 17 through a first pipeline. The outlet of the first expander unit 17 is fluidly connected to the inlet of the sixth refrigerant hydrogen channel of the third hydrogen cooler group 9. The outlet of the sixth refrigerant hydrogen channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the second refrigerant channel of the first hydrogen cooler group 7. The outlet of the second refrigerant channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the first compressor unit 18. The outlet of the fifth refrigeration channel of the third hydrogen cooler group 9 is also fluidly connected to the hydrogen storage tank 16 through a second pipeline. The throttle valve 15 is installed on the second pipeline. The liquid outlet of the hydrogen storage tank 16 is fluidly connected to the inlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group. The outlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group 10 is fluidly connected to the inlet of the hydrogen storage tank 16. The gas outlet of the hydrogen storage tank 16 is fluidly connected to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group 9. The outlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group 7. The outlet of the third refrigeration hydrogen channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the first compressor group 18. The integrated heat exchange unit 5 includes an expander and a cold storage module 25, as well as a heat pump and a heat storage module 26. The refrigerant inlet of the precooling and reheating unit 2 and the refrigerant inlet of the compressor cooler are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module 25, and the refrigerant outlet of the precooling and reheating unit 2 and the refrigerant outlet of the compressor cooler are each independently fluidly connected to the refrigerant inlet of the expander and cold storage module. The heat exchange medium inlet of the precooling and reheating unit 2 and the heat exchange medium inlet of the purifier 11 are each independently fluidly connected to the heat exchange medium outlet of the heat pump and heat storage module 26, and the heat exchange medium outlet of the precooling and reheating unit 2 and the heat exchange medium outlet of the purifier 11 are each independently fluidly connected to the heat exchange medium inlet of the heat pump and heat storage module 26. According to this disclosure, the compressor cooler can be anything well known to those skilled in the art, such as a chiller.

[0031] According to this disclosure, the expander and the cold storage module are equipped with devices for cold storage, which are well known to those skilled in the art and will not be described in detail here. The expander has a flow or pressure regulating device at its front end, which can continuously adjust the expander speed according to the cold storage status of the integrated heat exchange unit to control the output cooling capacity. The heat pump and the heat storage module can utilize low-grade heat to generate high-grade heat, and are equipped with devices for heat storage, such as a compressor, an expansion valve, and a heat storage medium.

[0032] According to this disclosure, the first hydrogen cooler group may include one or more coolers, preferably one cooler; the second hydrogen cooler group may include one or more coolers, preferably one cooler; the third cooler group may include one or more coolers, preferably multiple cooling units, for example, 2-6 coolers, more preferably 4 coolers, with each of the three upstream cooling units independently equipped with a first positive and negative hydrogen converter along the direction of raw material hydrogen flow; the fourth hydrogen cooler group may include one or more coolers, preferably one cooler.

[0033] According to this disclosure, the first expander unit may include multiple expanders, preferably 2-3 expanders arranged in series.

[0034] According to this disclosure, the first compressor unit may include multiple compressors, preferably including a first compressor and a second compressor arranged in series. In one specific embodiment, the outlet of the second refrigerant hydrogen passage of the first hydrogen cooler unit is in fluid communication with the inlet of the first compressor, and the outlet of the third refrigerant hydrogen passage of the first hydrogen cooler unit is in fluid communication with the inlet of the second compressor.

[0035] like Figure 2As shown, in one specific embodiment of this disclosure, the integrated heat exchange unit further includes a temperature sensor 27, a first heat exchanger 28, a first valve 29, and a refrigerant inlet pipeline; the refrigerant inlet pipeline includes a first refrigerant inlet pipeline main line, a first refrigerant inlet pipeline branch line, and a second refrigerant inlet pipeline branch line, and the first valve 29 is disposed on the second refrigerant inlet pipeline branch line; the outlet of the first refrigerant inlet pipeline branch line is fluidly connected to the refrigerant inlet of the expander and the cold storage module, the outlet of the second refrigerant inlet pipeline branch line is fluidly connected to the inlet of the heat exchange medium to be exchanged in the first heat exchanger, the outlet of the heat exchange medium to be exchanged in the first heat exchanger is fluidly connected to the refrigerant inlet of the expander and the cold storage module, the heat exchange medium inlet of the first heat exchanger is fluidly connected to the heat exchange medium outlet of the heat pump and the heat storage module, and the heat exchange medium outlet of the first heat exchanger is fluidly connected to the heat exchange medium inlet of the heat pump and the heat storage module. In this embodiment, a temperature sensor is used to determine the refrigerant temperature. When the temperature is too high, the first valve is opened to allow the refrigerant to enter the first heat exchanger for heat exchange. The heat is utilized and absorbed by the integrated heat exchange unit, further improving the energy utilization rate.

[0036] In one specific embodiment of this disclosure, the integrated heat exchange unit further includes a second heat exchanger 30, a first heat exchange medium pipeline 31, and a second heat exchange medium pipeline 32. The outlet of the first heat exchange medium pipeline 31 is in fluid communication with the heat exchange medium inlet of the heat pump and the heat storage module 26, the inlet of the first heat exchange medium pipeline 31 is in fluid communication with the heat exchange medium outlet of the second heat exchanger 30, the outlet of the second heat exchange medium pipeline 32 is in flow communication with the heat exchange medium inlet of the second heat exchanger, and the inlet of the second heat exchange medium pipeline 32 is in fluid communication with the heat exchange medium outlet of the heat pump and the heat storage module 26. Preferably, each of the first and second heat exchange medium pipelines is independently equipped with a valve. In this embodiment, when the expander and the cold storage module have excessively high initial operating temperatures, the expander and the cold storage module are in fluid communication with the heat pump and the heat storage module through the first and second heat exchange medium pipelines, and heat exchange occurs, allowing the heat pump and the heat storage module to absorb heat from the expander and the cold storage module.

[0037] To flexibly adjust the energy storage and release based on the temperature of the hydrogen liquefaction system, in one specific embodiment of this disclosure, the system includes multiple integrated heat exchange units. These multiple integrated heat exchange units are arranged in parallel or in series. When the expander and cold storage module, and / or the heat pump and thermal storage module malfunction, or when the expander and cold storage module, and / or the heat pump and thermal storage module are fully stored, the system can switch to other integrated heat exchange units to achieve continuous operation.

[0038] In one specific embodiment of this disclosure, the liquid nitrogen cooling unit includes a liquid nitrogen storage tank 19, a liquid nitrogen generator 20, and a second expander unit 21. The liquid outlet of the liquid nitrogen storage tank 19 is fluidly connected to the inlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group 8, the outlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group 8 is fluidly connected to the inlet of the liquid nitrogen storage tank 19, the gas outlet of the liquid nitrogen storage tank 19 is fluidly connected to the inlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group 7, the outlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the second expander unit 21, the outlet of the second expander unit 21 is fluidly connected to the refrigerant inlet of the expander and the cold storage module, the refrigerant outlet of the expander and the cold storage module is fluidly connected to the inlet of the liquid nitrogen generator 20, and the outlet of the liquid nitrogen generator 20 is fluidly connected to the inlet of the liquid nitrogen storage tank 19.

[0039] According to this disclosure, the purifier in the system can be installed in a cold box. To improve the flexibility of the purifier's use, in one specific embodiment of this disclosure, the purifier includes a first purifier and a second purifier connected in parallel. Each of the first and second purifiers independently contains one or more of activated carbon, fine-porous silica gel, and molecular sieves. In this disclosure, the first and second purifiers can be used interchangeably; when one purifier is used for regeneration, the other purifier can be started. After the regeneration process is complete, the purifier needs to be cooled rapidly. By employing a comprehensive heat exchange unit to recover and utilize the heat from the purifier, the energy utilization rate is improved. In one specific embodiment of this disclosure, the system further includes an air compression unit 6, which includes a third compressor unit 22, a compressed gas storage tank 23, and a screw compressor 24; the outlet of the third compressor unit 22 is connected to the inlet of the compressed gas storage tank 23, the outlet of the compressed gas storage tank 23 is connected to the compressed gas inlet of the screw compressor 24, and the gas outlet of the screw compressor is connected to the gas inlet of the precooling and reheating unit.

[0040] In one specific embodiment of this disclosure, the system further includes a liquid hydrogen tank, the gas outlet of which is fluidly connected via a third pipeline to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group, and / or fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group. In this embodiment, gaseous hydrogen from the liquid hydrogen tank can be introduced via the third pipeline for cooling exchange according to the cooling capacity requirements of the third hydrogen cooler group and the first cooler group, so as to fully utilize the cooling capacity of the gaseous hydrogen. In order to precool the liquid hydrogen tank, in one specific embodiment of this disclosure, the outlet of the fifth refrigeration channel of the third hydrogen cooler group is also fluidly connected to the inlet of the liquid hydrogen tank to precool the liquid hydrogen tank.

[0041] In one specific embodiment of this disclosure, the system further includes a PID control unit, which is used to control the recovery and release of cold and heat in the integrated heat exchange unit.

[0042] A second aspect of this disclosure provides a method for hydrogen liquefaction using the system provided in the first aspect of this disclosure. The method includes: introducing raw material hydrogen into the precooling and reheating unit for precooling, and introducing precooled hydrogen into the hydrogen liquefaction unit for hydrogen liquefaction; wherein the integrated heat exchange unit recovers the cooling and / or heating energy of the hydrogen liquefaction unit and the precooling and reheating unit, and provides cooling and / or heating energy to the hydrogen liquefaction unit and the precooling and reheating unit, and / or recovers the cooling energy of the hydrogen liquefaction unit.

[0043] The method disclosed herein can maximize the recovery and utilization of energy during the hydrogen liquefaction process, improve energy utilization efficiency, and reduce the energy consumption of the hydrogen liquefaction system.

[0044] In one specific embodiment of this disclosure, the method includes: introducing the refrigerant from the expander and cold storage module of the integrated heat exchange unit into the precooling and reheating unit for cooling exchange, and returning the cooled refrigerant to the expander and cold storage module for cold energy recovery; introducing the heat exchange medium from the heat pump and heat storage module of the integrated heat exchange unit into the purifier for heat exchange, and returning the cooled heat exchange medium to the heat pump and heat storage module for heat recovery.

[0045] In one specific embodiment of this disclosure, the method further includes: when the temperature of the main line of the first refrigerant inlet pipeline detected by the temperature sensor 27 is higher than the first preset temperature, opening the first valve 29, introducing a portion of the refrigerant from the branch line of the second refrigerant inlet pipeline into the first heat exchanger to exchange heat with the heat exchange medium from the heat pump and the heat storage module; and introducing the refrigerant after heat exchange from the branch line of the first refrigerant inlet pipeline into the expander and the cold storage module for cold energy recovery.

[0046] In one specific embodiment of this disclosure, the method further includes: when the initial operating temperature of the expander and the cold storage module is higher than the second preset temperature, introducing the heat exchange medium of the heat pump and the heat storage module into the second heat exchanger through the first heat exchange medium pipeline for heat exchange, and returning the heat exchange medium after heat exchange to the heat pump and the heat storage module through the second heat exchange medium pipeline.

[0047] In one specific embodiment of this disclosure, the process of introducing pre-cooled hydrogen into the hydrogen liquefaction unit for hydrogen liquefaction includes: sequentially introducing a first portion of pre-cooled hydrogen into the first raw material hydrogen channel of the first hydrogen cooler group and the second raw material hydrogen channel of the second hydrogen cooler group for first cooling; introducing the obtained first cooled hydrogen into the purifier for purification to obtain purified hydrogen; introducing the purified hydrogen into the third raw material hydrogen channel of the third hydrogen cooler group for second cooling and a first positive and negative hydrogen conversion reaction to obtain second cooled hydrogen; and introducing the second cooled hydrogen into the third raw material hydrogen channel of the fourth hydrogen cooler group for third cooling and a second positive and negative hydrogen conversion reaction to obtain liquefied hydrogen. The second portion of pre-cooled hydrogen is introduced into the first compressor unit for compression, and then sequentially introduced into the first refrigeration hydrogen channel of the first hydrogen cooler and the fourth refrigeration hydrogen channel of the second hydrogen cooler unit for cooling exchange. The first cooled hydrogen is introduced into the fifth refrigeration hydrogen channel of the third hydrogen cooler for cooling exchange with the raw material hydrogen. The resulting second cooled hydrogen is introduced into the first expander unit for expansion and cooling. The resulting cold hydrogen is sequentially introduced into the sixth refrigeration hydrogen channel of the third hydrogen cooler unit and the second refrigeration hydrogen channel of the first hydrogen cooler unit for cooling exchange. The cooled hydrogen is then reintroduced into the first compressor unit. The remaining portion of the second cooling hydrogen is throttled and cooled via a throttling valve on the second pipeline before being introduced into the hydrogen storage tank. The liquid hydrogen in the hydrogen storage tank is then introduced into the eighth cooling hydrogen channel of the fourth hydrogen cooler group for cooling. The cooled hydrogen is then introduced into the storage tank. The gaseous hydrogen in the storage tank is then sequentially introduced into the seventh cooling hydrogen channel of the third hydrogen cooler group and the third cooling hydrogen channel of the first hydrogen cooler group for cooling. The cooled hydrogen is then introduced into the first compressor group for compression.

[0048] In one specific embodiment of this disclosure, the method further includes: introducing gaseous nitrogen from the liquid nitrogen storage tank into the first liquid nitrogen refrigeration channel of the first hydrogen cooler group for cooling exchange to obtain cooled nitrogen; introducing the cooled nitrogen into the second expander group for expansion cooling, and introducing the obtained liquid nitrogen into the integrated heat exchange module to recover cooling capacity; introducing liquid nitrogen from the liquid nitrogen storage tank into the second liquid nitrogen refrigeration channel of the second hydrogen cooler group for cooling exchange, and introducing the cooled nitrogen back into the liquid nitrogen storage tank.

[0049] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0050] Example 1 like Figure 1As shown in the figure, this embodiment provides a process simulation diagram of a hydrogen liquefaction system that can recover a certain amount of hydrogen. The system includes: a pressure control unit 1, a precooling and reheating unit 2, a liquid nitrogen cooling unit 3, a hydrogen liquefaction unit 4, a comprehensive heat exchange unit 5, an air compression unit 6, and a compressor.

[0051] The pressure control unit 1 includes a first compressor unit 18; the hydrogen liquefaction unit includes a first hydrogen cooler unit 7, a second hydrogen cooler unit 8, a purifier, a third hydrogen cooler unit 9, a first neutral hydrogen converter 12, a fourth hydrogen cooler unit 10, a second neutral hydrogen converter 13, a compressor cooler 14, a throttle valve 15, a hydrogen storage tank 16, and a first expander unit 17; the first neutral hydrogen converter 12 is disposed within the third hydrogen cooler unit 9, and the second neutral hydrogen converter 13 is disposed within the fourth hydrogen cooler unit 10; the compressor cooler 14 is used to cool the compressor; The first hydrogen cooler group 7 includes a first raw material hydrogen channel, a first refrigerated hydrogen channel, a second refrigerated hydrogen channel, a third refrigerated hydrogen channel, and a first liquid nitrogen refrigeration channel; the second hydrogen cooler group 8 includes a second raw material hydrogen channel, a fourth refrigerated hydrogen channel, and a second liquid nitrogen refrigeration channel; the third hydrogen cooler group 9 includes a third raw material hydrogen channel, a fifth refrigerated hydrogen channel, a sixth refrigerated hydrogen channel, and a seventh refrigerated hydrogen channel; the fourth hydrogen cooler group 10 includes a fourth raw material hydrogen channel and an eighth refrigerated hydrogen channel. The outlet of the precooling and reheating unit 2 is fluidly connected to the inlet of the first raw material hydrogen channel of the first hydrogen cooler group 7. The outlet of the first raw material hydrogen channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the second raw material hydrogen channel of the second hydrogen cooler group 8. The outlet of the second raw material hydrogen channel of the second hydrogen cooler group 8 is fluidly connected to the inlet of the purifier 11. The outlet of the purifier 11 is fluidly connected to the inlet of the third raw material hydrogen channel of the third hydrogen cooler group 9. The outlet of the raw material hydrogen channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the raw material hydrogen channel of the fourth hydrogen cooler group and is fluidly connected to the raw material hydrogen inlet of the third hydrogen cooler group. The outlet of the precooling and reheating unit 2 is also fluidly connected to the inlet of the first compressor unit 18. The outlet of the first compressor unit 18 is fluidly connected to the inlet of the first refrigeration hydrogen channel of the first hydrogen cooler group 7. The outlet of the first refrigeration hydrogen channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the fourth refrigeration hydrogen channel of the second hydrogen cooler group 8. The outlet of the fourth refrigeration hydrogen channel of the second hydrogen cooler group 8 is fluidly connected to the inlet of the fifth refrigeration channel of the third hydrogen cooler group 9. The outlet of the fifth refrigeration channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the first expander unit 17 through the first pipeline. The outlet of the first expander unit 17 is fluidly connected to the inlet of the sixth refrigeration hydrogen channel of the third hydrogen cooler group 9. The outlet of the sixth refrigeration hydrogen channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the second refrigeration channel of the first hydrogen cooler group 7. The outlet of the second refrigeration channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the first compressor unit 18. The outlet of the fifth refrigeration channel of the third hydrogen cooler group 9 is also fluidly connected to the hydrogen storage tank 16 through a second pipeline. A throttle valve 15 is installed on the second pipeline. The liquid outlet of the hydrogen storage tank 16 is fluidly connected to the inlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group 10. The outlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group 10 is fluidly connected to the inlet of the hydrogen storage tank 16. The gas outlet of the hydrogen storage tank 16 is fluidly connected to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group 9. The outlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group 9 is fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group 7. The outlet of the third refrigeration hydrogen channel of the first hydrogen cooler group is fluidly connected to the inlet of the first compressor group. The integrated heat exchange unit 5 includes an expander and cold storage module 25, a heat pump and heat storage module 26, a temperature sensor 27, a first heat exchanger 28, a first valve 29, a refrigerant inlet pipeline, a second heat exchanger 30, a first heat exchange medium pipeline 31, and a second heat exchange medium pipeline 32. The first valve 29 is located on a branch of the second refrigerant inlet pipeline. The refrigerant inlet pipeline includes a main first refrigerant inlet pipeline, a branch first refrigerant inlet pipeline, and a branch second refrigerant inlet pipeline. The refrigerant inlet of the precooling and reheating unit 2 and the refrigerant inlet of the compressor cooler 14 are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module 25, and the refrigerant outlet of the precooling and reheating unit 2 and the refrigerant outlet of the compressor cooler 14 are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module 25. The heat exchange medium inlet of the precooling and reheating unit 2 and the heat exchange medium inlet of the purifier 11 are each independently connected to the heat exchange medium outlet of the heat pump and the heat storage module 16. The heat exchange medium outlet of the precooling and reheating unit 2 and the heat exchange medium outlet of the purifier 11 are each independently connected to the heat exchange medium inlet of the heat pump and the heat storage module 26. The outlet of the first heat exchange medium pipeline 31 is connected to the heat exchange medium inlet of the heat pump and the heat storage module 26. The inlet of the first heat exchange medium pipeline 31 is connected to the heat exchange medium outlet of the second heat exchanger 30. The outlet of the second heat exchange medium pipeline 32 is connected to the heat exchange medium inlet of the second heat exchanger 30. The inlet of the second heat exchange medium pipeline 32 is connected to the heat exchange medium outlet of the heat pump and the heat storage module 26.

[0052] The liquid nitrogen cooling unit includes a liquid nitrogen storage tank 19, a liquid nitrogen generator 20, and a second expander unit 21. The liquid outlet of the liquid nitrogen storage tank 19 is fluidly connected to the inlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group 8. The outlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group 8 is fluidly connected to the inlet of the liquid nitrogen storage tank 19. The gas outlet of the liquid nitrogen storage tank 19 is fluidly connected to the inlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group 7. The outlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group 7 is fluidly connected to the inlet of the second expander unit 21. The outlet of the second expander unit 21 is fluidly connected to the refrigerant inlet of the expander and cold storage module 25. The refrigerant outlet of the expander and cold storage module 25 is fluidly connected to the inlet of the liquid nitrogen generator 20. The outlet of the liquid nitrogen generator 20 is fluidly connected to the inlet of the liquid nitrogen storage tank 19.

[0053] The purifier includes a first purifier and a second purifier connected in parallel, each containing activated carbon independently.

[0054] The air compression unit includes a third compressor unit 22 and a compressed gas storage tank 23; the outlet of the third compressor unit 22 is connected to the inlet of the compressed gas storage tank 23, the outlet of the compressed gas storage tank is connected to the compressed gas inlet of the compressor, and the gas outlet of the compressor is connected to the gas inlet of the precooling and reheating unit.

[0055] The system disclosed herein can maximize the recovery and utilization of energy during the hydrogen liquefaction process, improve energy utilization efficiency, and reduce the energy consumption of the hydrogen liquefaction system.

[0056] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0058] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A hydrogen liquefaction system with potential quantity recovery, characterized in that, The system includes: a pressure control unit (1), a pre-cooling and reheating unit (2), a liquid nitrogen cooling unit (3), a hydrogen liquefaction unit (4), and a comprehensive heat exchange unit (5). The pressure control unit (1) is used to control the system pressure and maintain the system pressure stable. The precooling and reheating unit (2) is used to heat and reheat the system during the system start-up phase to remove residual liquid hydrogen in the system, and / or to precool the raw material hydrogen when the raw material hydrogen temperature is high. The liquid nitrogen cooling unit (3) is used to provide cooling for hydrogen liquefaction in the hydrogen liquefaction unit; The hydrogen liquefaction unit (4) is used to liquefy gaseous hydrogen; The integrated heat exchange unit (5) is used to recover the cold or heat of the hydrogen liquefaction unit and the precooling and reheating unit, and to provide cold and / or heat to the hydrogen liquefaction unit and the precooling and reheating unit. It is also used to recover the cold of the hydrogen liquefaction unit.

2. The hydrogen liquefaction system according to claim 1, wherein, The pressure control unit (1) includes a first compressor unit (18); The hydrogen liquefaction unit includes a first hydrogen cooler group (7), a second hydrogen cooler group (8), a purifier (11), a third hydrogen cooler group (9), a first intermediate hydrogen converter (12), a fourth hydrogen cooler group (10), a second intermediate hydrogen converter (13), a compressor cooler (14), a throttle valve (15), a hydrogen storage tank (16), and a first expander unit (17); the first intermediate hydrogen converter is located in the third hydrogen cooler group, and the second intermediate hydrogen converter is located in the fourth hydrogen cooler group; the compressor cooler is used to cool the compressor. The first hydrogen cooler group (7) includes a first raw material hydrogen channel, a first refrigerated hydrogen channel, a second refrigerated hydrogen channel, a third refrigerated hydrogen channel and a first liquid nitrogen refrigeration channel; The second hydrogen cooler assembly (8) includes a second raw material hydrogen channel, a fourth refrigerated hydrogen channel, and a second liquid nitrogen refrigeration channel; The third hydrogen cooler group (9) includes a third raw material hydrogen channel, a fifth refrigerated hydrogen channel, a sixth refrigerated hydrogen channel and a seventh refrigerated hydrogen channel; The fourth hydrogen cooler group (10) includes a fourth raw material hydrogen channel and an eighth cooling hydrogen channel; The outlet of the precooling and reheating unit (2) is fluidly connected to the inlet of the first raw material hydrogen channel of the first hydrogen cooler group (7), the outlet of the first raw material hydrogen channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the second raw material hydrogen channel of the second hydrogen cooler group (8), the outlet of the second raw material hydrogen channel of the second hydrogen cooler group (8) is fluidly connected to the inlet of the purifier (11), the outlet of the purifier (11) is fluidly connected to the inlet of the third raw material hydrogen channel of the third hydrogen cooler group (9), and the outlet of the third raw material hydrogen channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the raw material hydrogen channel of the fourth hydrogen cooler group (10). The outlet of the precooling and reheating unit (2) is also fluidly connected to the inlet of the first compressor unit (18), the outlet of the first compressor unit (18) is fluidly connected to the inlet of the first refrigeration hydrogen channel of the first hydrogen cooler group (7), the outlet of the first refrigeration hydrogen channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the fourth refrigeration hydrogen channel of the second hydrogen cooler group (8), and the outlet of the fourth refrigeration hydrogen channel of the second hydrogen cooler group (8) is fluidly connected to the inlet of the fifth refrigeration channel of the third hydrogen cooler group (9). The outlet of the fifth refrigeration channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the first expander unit (17) through the first pipeline. The outlet of the first expander unit (17) is fluidly connected to the inlet of the sixth refrigeration hydrogen channel of the third hydrogen cooler group (9). The outlet of the sixth refrigeration hydrogen channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the second refrigeration channel of the first hydrogen cooler group (7). The outlet of the second refrigeration channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the first compressor unit (18). The outlet of the fifth refrigeration channel of the third hydrogen cooler group (9) is also fluidly connected to the hydrogen storage tank (16) through the second pipeline. The throttle valve (15) is installed on the second pipeline. The liquid outlet of the hydrogen storage tank (16) is fluidly connected to the inlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group (10). The outlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group (10) is fluidly connected to the inlet of the hydrogen storage tank (16). The gas outlet of the hydrogen storage tank (16) is fluidly connected to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group (9). The outlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group (7). The outlet of the third refrigeration hydrogen channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the first compressor group (18). The integrated heat exchange unit includes an expander and a cold storage module (25), as well as a heat pump and a heat storage module (26). The refrigerant inlet of the precooling and reheating unit (2) and the refrigerant inlet of the compressor cooler (14) are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module (25), and the refrigerant outlet of the precooling and reheating unit (2) and the refrigerant outlet of the compressor cooler are each independently fluidly connected to the refrigerant inlet of the expander and cold storage module. The heat exchange medium inlet of the precooling and reheating unit (2) and the heat exchange medium inlet of the purifier (11) are each independently fluidly connected to the heat exchange medium outlet of the heat pump and heat storage module (26), and the heat exchange medium outlet of the precooling and reheating unit (2) and the heat exchange medium outlet of the purifier (11) are each independently fluidly connected to the heat exchange medium inlet of the heat pump and heat storage module (26).

3. The hydrogen liquefaction system according to claim 1, characterized in that, The integrated heat exchange unit (5) also includes a temperature sensor (27), a first heat exchanger (28), a first valve (29), and a refrigerant inlet pipeline; the refrigerant inlet pipeline includes a first refrigerant inlet pipeline main line, a first refrigerant inlet pipeline branch line, and a second refrigerant inlet pipeline branch line, and the first valve (29) is installed on the second refrigerant inlet pipeline branch line; The outlet of the first refrigerant inlet pipeline branch is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the outlet of the second refrigerant inlet pipeline branch is fluidly connected to the inlet of the heat exchange medium to be exchanged in the first heat exchanger; the outlet of the heat exchange medium to be exchanged in the first heat exchanger is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the inlet of the heat exchange medium of the first heat exchanger is fluidly connected to the outlet of the heat exchange medium of the heat pump and the heat storage module; and the outlet of the heat exchange medium of the first heat exchanger is fluidly connected to the inlet of the heat exchange medium of the heat pump and the heat storage module. Preferably, the integrated heat exchange unit further includes a second heat exchanger (30), a first heat exchange medium pipeline (31), and a second heat exchange medium pipeline (32). The outlet of the first heat exchange medium pipeline (31) is in fluid communication with the heat exchange medium inlet of the heat pump and heat storage module (26), the inlet of the first heat exchange medium pipeline (31) is in fluid communication with the heat exchange medium outlet of the second heat exchanger (30), the outlet of the second heat exchange medium pipeline (32) is in flow communication with the heat exchange medium inlet of the second heat exchanger (30), and the inlet of the second heat exchange medium pipeline (32) is in fluid communication with the heat exchange medium outlet of the heat pump and heat storage module (26). Preferably, the system includes multiple integrated heat exchange units; the multiple integrated heat exchange units are arranged in parallel or in series.

4. The hydrogen liquefaction system according to claim 2, characterized in that, The liquid nitrogen cooling unit (3) includes a liquid nitrogen storage tank (19), a liquid nitrogen generator (20), and a second expander unit (21). The liquid outlet of the liquid nitrogen storage tank (19) is fluidly connected to the inlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group (8), the outlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group (8) is fluidly connected to the inlet of the liquid nitrogen storage tank (19), the gas outlet of the liquid nitrogen storage tank (19) is fluidly connected to the inlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group (7), the outlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the second expander group (21), the outlet of the second expander group (21) is fluidly connected to the refrigerant inlet of the expander and cold storage module, the refrigerant outlet of the expander and cold storage module is fluidly connected to the inlet of the liquid nitrogen generator (20), and the outlet of the liquid nitrogen generator (20) is fluidly connected to the inlet of the liquid nitrogen storage tank (19).

5. The hydrogen liquefaction system according to claim 2, characterized in that, The purifier includes a first purifier and a second purifier arranged in parallel. Each of the first purifier and the second purifier independently contains one or more of the following: activated carbon, fine-pored silica gel, and molecular sieve.

6. The hydrogen liquefaction system according to claim 1, characterized in that, The system also includes an air compression unit (6), which includes a third compressor unit (22), a compressed gas storage tank (23), and a screw compressor (24). The outlet of the third compressor unit (22) is connected to the inlet of the compressed gas storage tank (23), the outlet of the compressed gas storage tank (23) is connected to the compressed gas inlet of the screw compressor (24), and the gas outlet of the screw compressor (24) is connected to the gas inlet of the precooling and reheating unit.

7. A method for hydrogen liquefaction using the system described in any one of claims 1-6, characterized in that, The method includes: introducing raw material hydrogen into the precooling and reheating unit for precooling, and introducing precooled hydrogen into the hydrogen liquefaction unit for hydrogen liquefaction; The integrated heat exchange unit recovers the cold and / or heat from the hydrogen liquefaction unit and the precooling and reheating unit, and provides cold and / or heat to the hydrogen liquefaction unit and the precooling and reheating unit, and / or recovers the cold from the hydrogen liquefaction unit.

8. The method according to claim 7, wherein, The integrated heat exchange unit includes an expander and a cold storage module (25), as well as a heat pump and a heat storage module (26). The refrigerant inlet of the precooling and reheating unit (2) and the refrigerant inlet of the compressor cooler (14) are each independently fluidly connected to the refrigerant outlet of the expander and cold storage module (25), and the refrigerant outlet of the precooling and reheating unit (2) and the refrigerant outlet of the compressor cooler are each independently fluidly connected to the refrigerant inlet of the expander and cold storage module. The heat exchange medium inlet of the precooling and reheating unit (2) and the heat exchange medium inlet of the purifier (11) are each independently fluidly connected to the heat exchange medium outlet of the heat pump and heat storage module (26), and the heat exchange medium outlet of the precooling and reheating unit (2) and the heat exchange medium outlet of the purifier (11) are each independently fluidly connected to the heat exchange medium inlet of the heat pump and heat storage module (26). The method includes: introducing the refrigerant from the expander and cold storage module of the integrated heat exchange unit into the precooling and reheating unit for heat exchange, and returning the refrigerant after heat exchange to the expander and cold storage module for heat recovery; The heat exchange medium of the heat pump and heat storage module of the integrated heat exchange unit is introduced into the purifier for heat exchange, and the heat exchange medium after heat exchange is returned to the heat pump and heat storage module for heat recovery.

9. The method according to claim 7, wherein, The integrated heat exchange unit (5) also includes a temperature sensor (27), a first heat exchanger (28), a first valve (29), and a refrigerant inlet pipeline; the refrigerant inlet pipeline includes a first refrigerant inlet pipeline main line, a first refrigerant inlet pipeline branch line, and a second refrigerant inlet pipeline branch line, and the first valve (29) is installed on the second refrigerant inlet pipeline branch line; The outlet of the first refrigerant inlet pipeline branch is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the outlet of the second refrigerant inlet pipeline branch is fluidly connected to the inlet of the heat exchange medium to be exchanged in the first heat exchanger; the outlet of the heat exchange medium to be exchanged in the first heat exchanger is fluidly connected to the refrigerant inlet of the expander and the cold storage module; the inlet of the heat exchange medium of the first heat exchanger is fluidly connected to the outlet of the heat exchange medium of the heat pump and the heat storage module; and the outlet of the heat exchange medium of the first heat exchanger is fluidly connected to the inlet of the heat exchange medium of the heat pump and the heat storage module. The method further includes: when the temperature of the main line of the first refrigerant inlet pipeline detected by the temperature sensor is higher than the first preset temperature, opening the first valve and introducing part of the refrigerant from the branch line of the second refrigerant inlet pipeline into the first heat exchanger to exchange heat with the heat exchange medium from the heat pump and the heat storage module; The refrigerant after heat exchange is introduced into the expander and cold storage module through the branch of the first refrigerant inlet pipeline for cold energy recovery.

10. The method according to claim 9, wherein, The integrated heat exchange unit also includes a second heat exchanger (30), a first heat exchange medium pipeline (31), and a second heat exchange medium pipeline (32). The outlet of the first heat exchange medium pipeline (31) is in fluid communication with the heat exchange medium inlet of the heat pump and heat storage module (26), the inlet of the first heat exchange medium pipeline (31) is in fluid communication with the heat exchange medium outlet of the second heat exchanger (30), the outlet of the second heat exchange medium pipeline (32) is in flow communication with the heat exchange medium inlet of the second heat exchanger (30), and the inlet of the second heat exchange medium pipeline (32) is in fluid communication with the heat exchange medium outlet of the heat pump and heat storage module (26). The method further includes: when the initial operating temperature of the expander and the cold storage module is higher than the second preset temperature, introducing the heat exchange medium of the heat pump and the heat storage module into the second heat exchanger through the first heat exchange medium pipeline for heat exchange, and returning the heat exchange medium after heat exchange to the heat pump and the heat storage module through the second heat exchange medium pipeline.

11. The method according to claim 7, wherein, The pressure control unit (1) includes a first compressor unit (18); The hydrogen liquefaction unit includes a first hydrogen cooler group (7), a second hydrogen cooler group (8), a purifier (11), a third hydrogen cooler group (9), a first intermediate hydrogen converter (12), a fourth hydrogen cooler group (10), a second intermediate hydrogen converter (13), a compressor cooler (14), a throttle valve (15), a hydrogen storage tank (16), and a first expander unit (17); the first intermediate hydrogen converter is located in the third hydrogen cooler group, and the second intermediate hydrogen converter is located in the fourth hydrogen cooler group; the compressor cooler is used to cool the compressor. The first hydrogen cooler group (7) includes a first raw material hydrogen channel, a first refrigerated hydrogen channel, a second refrigerated hydrogen channel, a third refrigerated hydrogen channel and a first liquid nitrogen refrigeration channel; The second hydrogen cooler assembly (8) includes a second raw material hydrogen channel, a fourth refrigerated hydrogen channel, and a second liquid nitrogen refrigeration channel; The third hydrogen cooler group (9) includes a third raw material hydrogen channel, a fifth refrigerated hydrogen channel, a sixth refrigerated hydrogen channel and a seventh refrigerated hydrogen channel; The fourth hydrogen cooler group (10) includes a fourth raw material hydrogen channel and an eighth cooling hydrogen channel; The outlet of the precooling and reheating unit (2) is fluidly connected to the inlet of the first raw material hydrogen channel of the first hydrogen cooler group (7), the outlet of the first raw material hydrogen channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the second raw material hydrogen channel of the second hydrogen cooler group (8), the outlet of the second raw material hydrogen channel of the second hydrogen cooler group (8) is fluidly connected to the inlet of the purifier (11), the outlet of the purifier (11) is fluidly connected to the inlet of the third raw material hydrogen channel of the third hydrogen cooler group (9), and the outlet of the third raw material hydrogen channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the raw material hydrogen channel of the fourth hydrogen cooler group (10). The outlet of the precooling and reheating unit (2) is also fluidly connected to the inlet of the first compressor unit (18), the outlet of the first compressor unit (18) is fluidly connected to the inlet of the first refrigeration hydrogen channel of the first hydrogen cooler group (7), the outlet of the first refrigeration hydrogen channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the fourth refrigeration hydrogen channel of the second hydrogen cooler group (8), and the outlet of the fourth refrigeration hydrogen channel of the second hydrogen cooler group (8) is fluidly connected to the inlet of the fifth refrigeration channel of the third hydrogen cooler group (9). The outlet of the fifth refrigeration channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the first expander unit (17) through the first pipeline. The outlet of the first expander unit (17) is fluidly connected to the inlet of the sixth refrigeration hydrogen channel of the third hydrogen cooler group (9). The outlet of the sixth refrigeration hydrogen channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the second refrigeration channel of the first hydrogen cooler group (7). The outlet of the second refrigeration channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the first compressor unit (18). The outlet of the fifth refrigeration channel of the third hydrogen cooler group (9) is also fluidly connected to the hydrogen storage tank (16) through the second pipeline. The throttle valve (15) is installed on the second pipeline. The liquid outlet of the hydrogen storage tank (16) is fluidly connected to the inlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group (10). The outlet of the eighth refrigeration hydrogen channel of the fourth hydrogen cooler group (10) is fluidly connected to the inlet of the hydrogen storage tank (16). The gas outlet of the hydrogen storage tank (16) is fluidly connected to the inlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group (9). The outlet of the seventh refrigeration hydrogen channel of the third hydrogen cooler group (9) is fluidly connected to the inlet of the third refrigeration hydrogen channel of the first hydrogen cooler group (7). The outlet of the third refrigeration hydrogen channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the first compressor group (18). The process of introducing pre-cooled hydrogen into the hydrogen liquefaction unit for hydrogen liquefaction includes: The first portion of pre-cooled hydrogen is sequentially introduced into the first raw material hydrogen channel of the first hydrogen cooler group and the second raw material hydrogen channel of the second hydrogen cooler group for first cooling. The obtained first cooled hydrogen is then introduced into the purifier for purification to obtain purified hydrogen. The purified hydrogen is then introduced into the third raw material hydrogen channel of the third hydrogen cooler group for second cooling and a first positive and negative hydrogen conversion reaction to obtain second cooled hydrogen. The second cooled hydrogen is then introduced into the third raw material hydrogen channel of the fourth hydrogen cooler group for third cooling and a second positive and negative hydrogen conversion reaction to obtain liquefied hydrogen. The second portion of pre-cooled hydrogen is introduced into the first compressor unit for compression, and then sequentially introduced into the first refrigeration hydrogen channel of the first hydrogen cooler and the fourth refrigeration hydrogen channel of the second hydrogen cooler unit for cooling exchange. The first cooled hydrogen is introduced into the fifth refrigeration hydrogen channel of the third hydrogen cooler for cooling exchange with the raw material hydrogen. The resulting second cooled hydrogen is introduced into the first expander unit through the first pipeline for expansion and cooling. The resulting cold hydrogen is sequentially introduced into the sixth refrigeration hydrogen channel of the third hydrogen cooler unit and the second refrigeration hydrogen channel of the first hydrogen cooler unit for cooling exchange. The cooled hydrogen is then reintroduced into the first compressor unit. The remaining portion of the second cooling hydrogen is throttled and cooled via a throttling valve on the second pipeline before being introduced into the hydrogen storage tank. The liquid hydrogen in the hydrogen storage tank is then introduced into the eighth cooling hydrogen channel of the fourth hydrogen cooler group for cooling. The cooled hydrogen is then introduced into the storage tank. The gaseous hydrogen in the storage tank is then sequentially introduced into the seventh cooling hydrogen channel of the third hydrogen cooler group and the third cooling hydrogen channel of the first hydrogen cooler group for cooling. The cooled hydrogen is then introduced into the first compressor group for compression.

12. The method according to claim 11, wherein, The liquid nitrogen cooling unit (3) includes a liquid nitrogen storage tank (19), a liquid nitrogen generator (20), and a second expander unit (21). The liquid outlet of the liquid nitrogen storage tank (19) is fluidly connected to the inlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group (8), the outlet of the second liquid nitrogen refrigeration channel of the second hydrogen cooler group (8) is fluidly connected to the inlet of the liquid nitrogen storage tank (19), the gas outlet of the liquid nitrogen storage tank (19) is fluidly connected to the inlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group (7), the outlet of the first liquid nitrogen refrigeration channel of the first hydrogen cooler group (7) is fluidly connected to the inlet of the second expander group (21), the outlet of the second expander group (21) is fluidly connected to the refrigerant inlet of the expander and cold storage module, the refrigerant outlet of the expander and cold storage module is fluidly connected to the inlet of the liquid nitrogen generator (20), and the outlet of the liquid nitrogen generator (20) is fluidly connected to the inlet of the liquid nitrogen storage tank (19). The method further includes: introducing gaseous nitrogen from the liquid nitrogen storage tank into the first liquid nitrogen refrigeration channel of the first hydrogen cooler group for cooling exchange to obtain cooled nitrogen; introducing the cooled nitrogen into the second expander unit for expansion cooling; and introducing the obtained liquid nitrogen into the integrated heat exchange module to recover the cooling capacity. The liquid nitrogen in the liquid nitrogen storage tank is introduced into the second liquid nitrogen refrigeration channel of the second hydrogen cooler group for cooling, and the cooled nitrogen is introduced back into the liquid nitrogen storage tank.

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