High-pressure gas hydrogen and liquid hydrogen combined filling system and method for recovering liquid hydrogen cold energy

Abstract

The invention belongs to the field of liquid hydrogen storage and filling, and discloses a high-pressure gas hydrogen and liquid hydrogen combined filling system and method for recovering liquid hydrogen cold energy, which comprises a high-pressure gas hydrogen filling system, a liquid hydrogen filling and BOG (boil-off gas) treatment system, a circulating gas cold-carrying liquid hydrogen cold energy recovery system and a hydrogen liquefaction system, high-pressure gas hydrogen and liquid hydrogen combined filling is realized by setting different liquid hydrogen supercharging pressures; liquid hydrogen cold energy recovery is achieved through heat exchange between circulating gas and liquid hydrogen; the recovered liquid hydrogen cold energy is used for hydrogen liquefaction precooling, so that the hydrogen liquefaction energy consumption cost is reduced, and liquid hydrogen self-supplement of the hydrogen refueling station is realized; liquid hydrogen cold energy is used for high-pressure gas hydrogen cooling, and high-pressure gas hydrogen filling cooling energy consumption is reduced; the high-pressure liquid hydrogen and the boil-off gas are introduced into the ejector, so that the boil-off gas is recondensed. According to the system, low-energy-consumption liquid hydrogen self-supplementation in the hydrogen refueling station can be achieved by comprehensively utilizing liquid hydrogen cold energy, and a new solution is provided for liquid hydrogen cold energy utilization and boil-off gas treatment of the liquid hydrogen refueling station.

Description

Technical Field

[0001] The present invention belongs to the field of liquid hydrogen storage and filling, and in particular relates to a high-pressure gas hydrogen and liquid hydrogen combined filling system and method for recovering liquid hydrogen cold energy. Background Art

[0002] Hydrogen fuel cells are regarded as a highly potential power source, especially in the field of transportation. To this end, the development of safe, efficient and low-energy hydrogenation technology has important engineering practical value. Hydrogenation stations mainly include high-pressure gaseous hydrogen filling and liquid hydrogen filling. Liquid hydrogen filling stations occupy a small area, have a high degree of safety and low transportation costs. With the development of the hydrogen energy industry and the advancement of hydrogen liquefaction technology, liquid hydrogen filling stations may become mainstream. At present, hydrogen storage methods in hydrogen energy vehicles include 35MPa high-pressure gas cylinder hydrogen storage, 70MPa high-pressure gas cylinder hydrogen storage, and liquid hydrogen storage. For this reason, hydrogenation stations still coexist with high-pressure gas hydrogen filling and liquid hydrogen filling. Due to the high efficiency of liquid hydrogen pressurization, low energy consumption, and multiple modes of high-pressure gas hydrogen filling and liquid hydrogen filling, it has the advantages of flexible and diverse hydrogen supply. However, liquid hydrogen filling stations need to solve problems such as liquid hydrogen storage, liquid hydrogen pressurization, boil-off gas treatment, and liquid hydrogen cold energy recovery and utilization, which are more technically difficult.

[0003] Boiling off gas (BOG) is evaporated hydrogen produced during the storage and transportation of liquid hydrogen due to factors such as heat leakage and flash evaporation. Boil-off gas can cause overpressure in liquid hydrogen storage tanks. If not resolved in a timely manner, it will pose a safety hazard to the tanks. At present, the most common way to deal with boil-off gas in hydrogen refueling stations is to discharge it directly or compress it to 45MPa for refueling. For the direct compression solution, the boil-off gas is compressed from the tank pressure of 0.1-0.2MPa to 45MPa. The pressure ratio is large, the energy consumption is high, and the amount of boil-off gas is small and unstable. Therefore, this solution is not economical in terms of energy consumption and equipment investment.

[0004] Liquid hydrogen releases a large amount of cold energy during the process of heating and gasification. The reasonable recovery of this cold energy is crucial to reducing the energy consumption of liquid hydrogen refueling stations. At present, there are many new solutions for the recovery and utilization of liquid hydrogen cold energy and the treatment of boil-off gas in liquid hydrogen refueling stations at home and abroad; for example: Chinese patent application number CN115013721A discloses a high-efficiency liquid hydrogen refueling station hydrogenation system and method, which realizes boil-off gas recondensation by pressurizing liquid hydrogen and boil-off gas separately and then mixing them, and recovers liquid hydrogen cold energy for cooling the high-pressure gas hydrogen to be filled. Chinese patent application CN108561749A discloses a mixed filling system for liquid hydrogen refueling station, which uses a compressor to compress the boil-off gas and temporarily stores it in a storage tank, and uses liquid hydrogen cold energy to reduce the boil-off gas compression temperature and the filling high-pressure gas hydrogen temperature; in the above schemes, the boil-off gas treatment scheme still uses a compressor to compress the boil-off gas, which cannot reduce the additional equipment investment caused by the boil-off gas; Chinese patent application CN117287628A discloses a liquid hydrogen booster type hydrogen refueling station and its operation method, which uses a solid cold box cold storage method to store liquid hydrogen cold energy for gas hydrogen compression and cooling and cooling the filled high-pressure gas hydrogen; but this scheme uses liquid hydrogen cold energy in a higher temperature zone, resulting in a large amount of precious low temperature zone cold energy being inefficiently used; Chinese patent CN217875296U discloses a cascade liquid hydrogen refueling station cold energy recovery system, which uses nitrogen, carbon dioxide, and ethylene glycol solution as working fluids to achieve three-level recovery of liquid hydrogen cold energy, but this scheme is complex and cannot solve the problem of liquid hydrogen cold energy application in different temperature zones, and does not propose a more suitable boil-off gas treatment scheme.

[0005] It can be seen that the existing liquid hydrogen refueling stations mostly use compressors to compress the evaporated gas for the treatment of liquid hydrogen, which requires the installation of additional dynamic machinery, resulting in high energy consumption of the overall system and causing huge energy loss. Summary of the invention

[0006] The present invention provides a high-pressure gas-hydrogen-liquid hydrogen combined filling system and method for recovering liquid hydrogen cold energy, so as to solve the technical problem that the existing liquid hydrogen refueling station mainly uses a compressor to compress the evaporated gas for the treatment of liquid hydrogen, which requires the addition of additional power machinery, resulting in high energy consumption of the overall system and causing huge energy loss.

[0007] In order to achieve the above object, the present invention adopts the following technical contents: A high-pressure gas-hydrogen and liquid-hydrogen combined filling system for recovering liquid hydrogen cold energy, comprising a high-pressure gas-hydrogen filling system, a liquid hydrogen filling and BOG treatment system, a circulating gas-cooled liquid hydrogen cold energy recovery system, and a hydrogen liquefaction system; The high-pressure gas hydrogen filling system is used to pressurize the liquid hydrogen output by the hydrogen liquefaction system to achieve high-pressure gas hydrogen filling; The liquid hydrogen filling and BOG treatment system is used to process the liquid hydrogen boil-off gas output by the hydrogen liquefaction system and realize liquid hydrogen filling; The circulating gas-cooled liquid hydrogen cold energy recovery system is used to realize liquid hydrogen cold energy recovery by exchanging heat between the circulating gas and the low-temperature and high-pressure liquid hydrogen in the high-pressure gas hydrogen filling system; The hydrogen liquefaction system is used to pre-cool the raw material high-purity hydrogen gas using the cold energy recovered by the liquid hydrogen cold energy recovery system with circulating gas cooling, and then complete the liquefaction of the raw material high-purity hydrogen gas to output liquid hydrogen; Wherein, the liquid hydrogen filling and BOG treatment system comprises: a connected ejector and a medium-pressure liquid hydrogen storage tank; The liquid hydrogen boil-off gas output by the hydrogen liquefaction system serves as the ejected fluid of the ejector; the hydrogen liquefaction system is connected to the working fluid inlet of the ejector via a low-pressure liquid hydrogen pump; The liquid hydrogen boil-off gas is mixed with the low-pressure liquid hydrogen pressurized by the hydrogen liquefaction system through the ejector, and the liquid hydrogen boil-off gas enters the medium-pressure liquid hydrogen storage tank after being condensed; The liquid hydrogen in the medium-pressure liquid hydrogen storage tank is used for liquid hydrogen filling or provides liquid hydrogen supplement for the hydrogen liquefaction system after being depressurized.

[0008] Further, the hydrogen liquefaction system includes a low-pressure liquid hydrogen storage tank, a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a sixth heat exchanger, a helium compressor unit, a stage aftercooler, a seventh heat exchanger, an eighth heat exchanger, a ninth heat exchanger, a first cryogenic helium expander, a second cryogenic helium expander and a third cryogenic helium expander; The hot side inlet of the first heat exchanger is connected to the raw material high-purity hydrogen source, and the hot side outlet of the first heat exchanger is sequentially connected to the hot side inlet of the second heat exchanger, the hot side inlet of the third heat exchanger, the hot side inlet of the fourth heat exchanger, the hot side inlet of the fifth heat exchanger, the hot side inlet of the sixth heat exchanger, the first valve and the ejector working fluid inlet; The medium-pressure liquid hydrogen storage tank is connected to the low-pressure liquid hydrogen storage tank via a throttle valve; The top of the low-pressure liquid hydrogen storage tank is connected to the ejector; The low-pressure liquid hydrogen storage tank is connected to the working fluid inlet of the ejector through a third valve and a low-pressure liquid hydrogen pump, and is also connected to the high-pressure gas hydrogen filling system; The high-pressure helium outlet of the helium compressor unit is connected to the stage aftercooler, and the stage aftercooler outlet is respectively connected to the hot side inlet of the seventh heat exchanger, the hot side inlet of the eighth heat exchanger, and the hot side inlet of the ninth heat exchanger; The hot side outlet of the seventh heat exchanger, the hot side outlet of the eighth heat exchanger, and the hot side outlet of the ninth heat exchanger are respectively connected to the inlet of the first cryogenic helium expander, the inlet of the second cryogenic helium expander, and the inlet of the third cryogenic helium expander; The first cryogenic helium expander outlet, the second cryogenic helium expander outlet, and the third cryogenic helium expander outlet are respectively connected to the cold side inlet of the fourth heat exchanger, the cold side inlet of the fifth heat exchanger, and the cold side inlet of the sixth heat exchanger; The cold side outlet of the fourth heat exchanger, the cold side outlet of the fifth heat exchanger, and the cold side outlet of the sixth heat exchanger are respectively connected to the cold side inlet of the seventh heat exchanger, the cold side inlet of the eighth heat exchanger, and the cold side inlet of the ninth heat exchanger; The cold side outlet of the seventh heat exchanger, the cold side outlet of the eighth heat exchanger, and the cold side outlet of the ninth heat exchanger are connected to the low-pressure inlet of the helium compressor unit.

[0009] Furthermore, the hot runners of the first heat exchanger, the second heat exchanger, the third heat exchanger, the fourth heat exchanger, and the fifth heat exchanger are all filled with ortho-parahydrogen conversion catalysts, and a continuous conversion method is used to catalyze the conversion of orthohydrogen into parahydrogen.

[0010] Furthermore, the high-pressure gas hydrogen filling system includes a first low-temperature liquid hydrogen pump and a second low-temperature liquid hydrogen pump respectively connected to the liquid hydrogen output end of the hydrogen liquefaction system; the first low-temperature liquid hydrogen pump is connected to the first liquid hydrogen evaporator, the first high-pressure gas storage cylinder and the filling cooling system in sequence through the liquid hydrogen cold energy recovery system cooled by the circulating gas; the second low-temperature liquid hydrogen pump is connected to the second liquid hydrogen evaporator, the second high-pressure gas storage cylinder and the filling cooler in sequence through the liquid hydrogen cold energy recovery system cooled by the circulating gas.

[0011] Furthermore, the first cryogenic liquid hydrogen pump adopts a 45MPa cryogenic liquid hydrogen pump, and the second cryogenic liquid hydrogen pump adopts a 90MPa cryogenic liquid hydrogen pump; the first high-pressure gas storage cylinder adopts a 45MPa high-pressure gas storage cylinder, and the second high-pressure gas storage cylinder adopts a 90MPa high-pressure gas storage cylinder; the filling cooling system adopts a 35MPa filling cooling system, and the filling cooler adopts a 70MPa filling cooler.

[0012] Furthermore, the 35MPa charging cooling system adopts a vapor compression refrigeration system.

[0013] Further, the liquid hydrogen cold energy recovery system with circulating gas cooling includes a circulating gas compressor, a circulating gas cooler and a cold energy recovery device; the circulating gas outlet of the circulating gas compressor is connected to the circulating gas cooler inlet, the circulating gas cooler outlet is connected to the hot side inlet of the cold energy recovery device, and the hot side outlet of the cold energy recovery device is respectively connected to the hot side inlet of the first liquid hydrogen evaporator and the hot side inlet of the second liquid hydrogen evaporator; the first liquid hydrogen evaporator is connected to the first low-temperature liquid hydrogen pump, and the second liquid hydrogen evaporator is connected to the second low-temperature liquid hydrogen pump; the cold side outlet of the first heat exchanger of the hydrogen liquefaction system is connected to the circulating gas inlet of the circulating gas compressor; the cold side outlet of the second heat exchanger is connected to the cold side inlet of the filling cooler; the cold side outlet of the filling cooler is connected to the circulating gas inlet of the circulating gas compressor; wherein, after being pressurized by the circulating gas compressor, the circulating gas enters the cold energy recovery device, the first liquid hydrogen evaporator, and the second liquid hydrogen evaporator to recover the liquid hydrogen evaporation cold energy, and then enters the hydrogen liquefaction system and the filling cooler to provide cold energy for hydrogen liquefaction precooling and high-pressure hydrogen filling cooling.

[0014] Furthermore, the circulating gas of the circulating gas compressor is an inert gas, and the inert gas is nitrogen or argon.

[0015] A working method of a high-pressure gas-hydrogen-liquid hydrogen combined filling system for recovering liquid hydrogen cold energy, based on the above-mentioned high-pressure gas-hydrogen-liquid hydrogen combined filling system for recovering liquid hydrogen cold energy, comprising: The hydrogen liquefaction system uses the cold energy recovered from the circulating gas to pre-cool the raw high-purity hydrogen, and then liquefies the raw high-purity hydrogen to output liquid hydrogen; The high-pressure gas hydrogen filling system pressurizes the liquid hydrogen output by the hydrogen liquefaction system to achieve high-pressure gas hydrogen filling; The liquid hydrogen filling and BOG treatment system processes the liquid hydrogen boil-off gas output by the hydrogen liquefaction system and realizes liquid hydrogen filling; The circulating gas-cooled liquid hydrogen cold energy recovery system realizes liquid hydrogen cold energy recovery through heat exchange between the circulating gas and the low-temperature and high-pressure liquid hydrogen in the high-pressure gas hydrogen filling system; The low-pressure liquid hydrogen pump pressurizes the low-pressure liquid hydrogen in the hydrogen liquefaction system; The liquid hydrogen boil-off gas output by the hydrogen liquefaction system is mixed with the low-pressure liquid hydrogen pressurized by the hydrogen liquefaction system through an ejector, and the liquid hydrogen boil-off gas enters the medium-pressure liquid hydrogen storage tank after condensation; Liquid hydrogen is added by using liquid hydrogen in a medium-pressure liquid hydrogen storage tank, or the liquid hydrogen is depressurized to replenish liquid hydrogen for the hydrogen liquefaction system.

[0016] Furthermore, after the high-purity hydrogen enters the hydrogen liquefaction system, it is cooled through a six-stage heat exchanger. The low-temperature and high-pressure liquid hydrogen at the hot side outlet of the hydrogen liquefaction system enters the ejector as the working fluid, where the evaporated gas is recondensed and then stored in the medium-pressure liquid hydrogen storage tank.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a high-pressure gas hydrogen and liquid hydrogen joint filling system for recovering liquid hydrogen cold energy. The system includes a high-pressure gas hydrogen filling system, a liquid hydrogen filling and BOG treatment system, a circulating gas-cooled liquid hydrogen cold energy recovery system, and a hydrogen liquefaction system. The system sets different liquid hydrogen boosting pressures to realize high-pressure gas hydrogen and liquid hydrogen joint filling; utilizes circulating gas and liquid hydrogen heat exchange to realize liquid hydrogen cold energy recovery; by using the recovered liquid hydrogen cold energy for hydrogen liquefaction precooling, the hydrogen liquefaction energy consumption cost is reduced, and the hydrogen filling station liquid hydrogen self-replenishment is realized; by using liquid hydrogen cold energy for high-pressure gas hydrogen cooling, the high-pressure gas hydrogen filling cooling energy consumption is reduced; by introducing high-pressure liquid hydrogen and boil-off gas into an ejector, boil-off gas recondensation is realized. The system can realize low-energy liquid hydrogen self-replenishment in the hydrogen filling station by comprehensively utilizing liquid hydrogen cold energy, and has the boil-off gas processing function of the liquid hydrogen filling station without adding external dynamic machinery, providing a new solution to the problems of liquid hydrogen cold energy utilization and boil-off gas processing in the liquid hydrogen filling station. The system does not need to add additional dynamic machinery, which reduces the energy consumption of the overall system.

[0018] Preferably, in the present invention, circulating gas cooling is utilized to realize efficient and low-cost recovery of liquid hydrogen cooling capacity in a liquid hydrogen refueling station, and the recovered cold energy is applied to pre-cooling of hydrogen liquefaction and cooling of 70MPa high-pressure hydrogen filling, thereby realizing comprehensive and reasonable utilization of liquid hydrogen cooling energy in a larger temperature range.

[0019] Preferably, in the present invention, the cold energy of liquid hydrogen in the liquid hydrogen refueling station is recovered and utilized in the hydrogen liquefaction pre-cooling stage, a helium reverse Brayton cryogenic refrigeration system is composed of a helium compressor unit, a stage aftercooler, etc., and the low-temperature cooling capacity obtained by expanding the high-pressure helium is used in the hydrogen liquefaction deep cooling stage, thereby realizing low-energy self-replenishment of liquid hydrogen in the liquid hydrogen refueling station, and providing an efficient and reasonable new solution for the comprehensive utilization of energy in liquid hydrogen refueling stations that use pipeline transportation as the main hydrogen source.

[0020] Preferably, in the present invention, the ejector is used as the key component for BOG pressure boosting and recondensation, the high-pressure liquid hydrogen in the hydrogen liquefaction system is used as the working fluid, and the liquid hydrogen boil-off gas is used as the ejected fluid, so that boil-off gas recondensation is achieved, and boil-off gas treatment of the liquid hydrogen refueling station is completed in a low energy consumption and low investment manner. Preferably, in the present invention, a solution is proposed for the efficient joint filling of high-pressure gaseous hydrogen and liquid hydrogen to solve the problems of efficient recovery and utilization of liquid hydrogen cooling energy and recondensation of boil-off gas in liquid hydrogen refueling stations, which has the functions of efficient recovery of liquid hydrogen cooling energy, low-energy self-replenishment of liquid hydrogen, boil-off gas recondensation, 35MPa and 70MPa high-pressure gaseous hydrogen cooling and filling, and liquid hydrogen filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural block diagram of a high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy provided by the present invention.

[0022] Reference numerals: 1. Low-pressure liquid hydrogen storage tank; 2. First cryogenic liquid hydrogen pump; 3. Second cryogenic liquid hydrogen pump; 4. First liquid hydrogen evaporator; 5. Second liquid hydrogen evaporator; 6. Cold energy recovery device; 7. First high-pressure gas storage bottle; 8. Second high-pressure gas storage bottle; 9. First outlet valve; 10. Second outlet valve; 11. First heat exchanger; 12. Second heat exchanger; 13. Third heat exchanger; 14. Fourth heat exchanger; 15. Fifth heat exchanger; 16. Sixth heat exchanger; 17. First valve; 18. Ejector; 1 9. Medium-pressure liquid hydrogen storage tank; 20. Second valve; 21. Helium compressor unit; 22. After-stage cooler; 23. Seventh heat exchanger; 24. Eighth heat exchanger; 25. Ninth heat exchanger; 26. First cryogenic helium expander; 27. Second cryogenic helium expander; 28. Third cryogenic helium expander; 29. ​​Circulating gas compressor; 30. Circulating gas cooler; 31. Filling cooler; 32. Filling cooling system; 33. Low-pressure liquid hydrogen pump; 34. Throttle valve; 35. Third valve. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Example 1 like Figure 1 As shown, this embodiment provides a high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy, including a high-pressure gas hydrogen filling system, a liquid hydrogen filling and BOG treatment system, a circulating gas-cooled liquid hydrogen cold energy recovery system, and a hydrogen liquefaction system. The specific structure is as follows: The high-pressure gas hydrogen filling system consists of a low-pressure liquid hydrogen storage tank 1, a first cryogenic liquid hydrogen pump 2, a first liquid hydrogen evaporator 4, a second cryogenic liquid hydrogen pump 3, a second liquid hydrogen evaporator 5, a cold energy recovery device 6, a first high-pressure gas storage bottle 7, a filling cooling system 32, a second high-pressure gas storage bottle 8, and a filling cooler 31. The liquid hydrogen in the low-pressure liquid hydrogen storage tank 1 is connected to the first cryogenic liquid hydrogen pump 2 and the second cryogenic liquid hydrogen pump 3, respectively. The high-pressure outlets of the first cryogenic liquid hydrogen pump 2 and the second cryogenic liquid hydrogen pump 3 are connected to the cold side inlet of the first liquid hydrogen evaporator 4 and the second liquid hydrogen evaporator 4, respectively. The cold side inlet of the evaporator 5 is connected, the cold side outlet of the first liquid hydrogen evaporator 4 is connected to the inlet of the first high-pressure gas storage bottle 7 through the first cold side flow channel of the cold energy recovery device 6, and the outlet of the first high-pressure gas storage bottle 7 can be filled with 35MPa high-pressure hydrogen through the first outlet valve 9 and the filling cooling system 33. The cold side outlet of the second liquid hydrogen evaporator 5 is connected to the inlet of the second high-pressure gas storage bottle 8 through the second cold side flow channel of the cold energy recovery device 6, and the outlet of the second high-pressure gas storage bottle 8 can be filled with 70MPa high-pressure hydrogen through the second outlet valve 10 and the filling cooler 31. The low-pressure liquid hydrogen is pressurized and evaporated and is stored in the first high-pressure gas storage cylinder 7 and the second high-pressure gas storage cylinder 8 respectively, wherein the cold energy of evaporation of liquid hydrogen is recovered by the circulating gas circulation loop in the first liquid hydrogen evaporator 4, the second liquid hydrogen evaporator 5 and the cold energy recovery device 6, and the high-pressure hydrogen in the first high-pressure gas storage cylinder 7 is cooled by the filling cooling system 32 to achieve 35MPa high-pressure hydrogen filling, and the high-pressure hydrogen in the second high-pressure gas storage cylinder 8 is cooled by the filling cooler 31 to achieve 70MPa high-pressure hydrogen filling.

[0031] The liquid hydrogen filling and BOG treatment system consists of a low-pressure liquid hydrogen storage tank 1, a low-pressure liquid hydrogen pump 33, an ejector 18, and a medium-pressure liquid hydrogen storage tank 19, wherein the liquid hydrogen in the low-pressure liquid hydrogen storage tank 1 is connected to the low-pressure liquid hydrogen pump 33 via a third valve 35, the outlet of the low-pressure liquid hydrogen pump 33 is connected to the working fluid inlet of the ejector 18, and the liquid hydrogen evaporated gas BOG enters the ejector 18 as the ejected fluid. The low-pressure liquid hydrogen is pressurized by the low-pressure liquid hydrogen pump 33 and enters the ejector as the working fluid, and is mixed with the liquid hydrogen evaporated gas BOG as the ejected fluid, and enters the medium-pressure liquid hydrogen storage tank 19 after the evaporated gas is recondensed. The liquid hydrogen in the medium-pressure liquid hydrogen storage tank 19 can be used for liquid hydrogen filling or used to supplement the liquid hydrogen in the low-pressure liquid hydrogen storage tank 1 after being depressurized by the throttle valve 34; The liquid hydrogen cold energy recovery system with circulating gas cooling is composed of a circulating gas compressor 29, a circulating gas cooler 30, a cold energy recovery device 6, a first liquid hydrogen evaporator 4, a second liquid hydrogen evaporator 5, a third heat exchanger 13, a second heat exchanger 12, a first heat exchanger 11, and a charging cooler 31. The circulating gas outlet of the circulating gas compressor 29 is connected to the inlet of the circulating gas cooler 30, the outlet of the circulating gas cooler 30 is connected to the hot side inlet of the cold energy recovery device 6, and the hot side outlet of the cold energy recovery device 6 is connected to the first The hot side inlet of the liquid hydrogen evaporator 4 and the hot side inlet of the second liquid hydrogen evaporator 5, the hot side outlet of the first liquid hydrogen evaporator 4 is connected to the cold side inlet of the third heat exchanger 13, the cold side outlet of the third heat exchanger 13 and the hot side outlet of the second liquid hydrogen evaporator 5 are connected to the cold side inlet of the second heat exchanger 12, the cold side outlet of the second heat exchanger 12 is connected to the cold side inlet of the first heat exchanger 11 and the cold side inlet of the charging cooler 31, and the cold side outlet of the first heat exchanger 11 and the cold side outlet of the charging cooler 31 are connected to the circulating gas inlet of the circulating gas compressor 29. After being pressurized by the circulating gas compressor 29, the circulating gas enters the cold energy recovery device 6, the first liquid hydrogen evaporator 4, and the second liquid hydrogen evaporator 5 to recover the cold energy of liquid hydrogen evaporation, and then enters the third heat exchanger 13, the second heat exchanger 12, the first heat exchanger 11, and the charging cooler 31 in turn to provide cold energy for hydrogen liquefaction precooling and 70MPa high-pressure hydrogen charging cooling.

[0032] The hydrogen liquefaction system is composed of a first heat exchanger 11, a second heat exchanger 12, a third heat exchanger 13, a fourth heat exchanger 14, a fifth heat exchanger 15, a sixth heat exchanger 16, a helium compressor unit 21, a stage aftercooler 22, a seventh heat exchanger 23, an eighth heat exchanger 24, a ninth heat exchanger 25, a first cryogenic helium expander 26, a second cryogenic helium expander 27, a third cryogenic helium expander 28, an ejector 18, a medium-pressure liquid hydrogen storage tank 19, a throttle valve 34, and a low-pressure liquid hydrogen storage tank 1, wherein the hot side inlet of the first heat exchanger 11 The raw material high-purity hydrogen source is connected, the hot side outlet of the first heat exchanger 11 is sequentially connected to the hot side inlet of the second heat exchanger 12, the hot side inlet of the third heat exchanger 13, the hot side inlet of the fourth heat exchanger 14, the hot side inlet of the fifth heat exchanger 15, the hot side inlet of the sixth heat exchanger 16, the first valve 17 and the working fluid inlet of the ejector 18, the ejector 18 outlet is connected to the inlet of the medium-pressure liquid hydrogen storage tank 19, the medium-pressure liquid hydrogen storage tank 19 is connected to the two outlets of the second valve 20 and the throttle valve 34, the throttle valve 34 is connected to the low-pressure liquid hydrogen storage tank 1, and the helium compressor unit 21 is connected to the second valve 20. The high-pressure helium outlet is connected to the stage aftercooler 22, and the stage aftercooler 22 outlet is respectively connected to the hot side inlet of the seventh heat exchanger 23, the hot side inlet of the eighth heat exchanger 24, and the hot side inlet of the ninth heat exchanger 25. The hot side outlet of the seventh heat exchanger 23, the hot side outlet of the eighth heat exchanger 24, and the hot side outlet of the ninth heat exchanger 25 are respectively connected to the inlet of the first cryogenic helium expander 26, the inlet of the second cryogenic helium expander 27, and the inlet of the third cryogenic helium expander 28. The outlet of the first cryogenic helium expander 26, the outlet of the second cryogenic helium expander 27, and the outlet of the third The outlet of the cryogenic helium expander 28 is respectively connected to the cold side inlet of the fourth heat exchanger 14, the cold side inlet of the fifth heat exchanger 15, and the cold side inlet of the sixth heat exchanger 16; the cold side outlet of the fourth heat exchanger 14, the cold side outlet of the fifth heat exchanger 15, and the cold side outlet of the sixth heat exchanger 16 are respectively connected to the cold side inlet of the seventh heat exchanger 23, the cold side inlet of the eighth heat exchanger 24, and the cold side inlet of the ninth heat exchanger 25; the cold side outlet of the seventh heat exchanger 23, the cold side outlet of the eighth heat exchanger 24, and the cold side outlet of the ninth heat exchanger 25 are connected to the low-pressure inlet of the helium compressor unit 21. After the high-purity hydrogen enters the hydrogen liquefaction system, it is cooled by six stages of heat exchangers in succession, wherein the low-temperature side cold energy of the first heat exchanger 11, the second heat exchanger 12, and the third heat exchanger 13 comes from the liquid hydrogen cold energy obtained by recycling the circulating gas, and the low-temperature side cold energy of the fourth heat exchanger 14, the fifth heat exchanger 15, and the sixth heat exchanger 16 comes from the cold energy obtained by helium expansion refrigeration in the reverse Brayton cycle. The low-temperature and high-pressure liquid hydrogen at the hot side outlet of the sixth heat exchanger 16 enters the ejector 18 as a working fluid, and the evaporated gas is recondensed in the ejector 18 and then enters the medium-pressure liquid hydrogen storage tank 19 for storage. The liquid hydrogen in the medium-pressure liquid hydrogen storage tank 19 can be filled with liquid hydrogen through the second valve 20, or part of it can be expanded and cooled through the throttle valve 34 and then refluxed to the low-pressure liquid hydrogen storage tank 1.

[0033] In this embodiment, in order to facilitate meeting the high-pressure hydrogen filling needs of different pressures, the first cryogenic liquid hydrogen pump 2 adopts a 45MPa cryogenic liquid hydrogen pump, and the second cryogenic liquid hydrogen pump 3 adopts a 90MPa cryogenic liquid hydrogen pump; the first high-pressure gas storage cylinder 7 adopts a 45MPa high-pressure gas storage cylinder, and the second high-pressure gas storage cylinder 8 adopts a 90MPa high-pressure gas storage cylinder; the filling cooling system 32 adopts a 35MPa filling cooling system, and the filling cooler 31 adopts a 70MPa filling cooler 31.

[0034] In the present embodiment, it should be noted that: taking the low-pressure liquid hydrogen storage tank 1 as an example, since the entire system provided in the present embodiment belongs to a complete large circulation system, the low-pressure liquid hydrogen storage tank 1 is included in the high-pressure gas hydrogen filling system and is also a component of the hydrogen liquefaction system; that is to say, the repeated components appearing in the above-mentioned two different systems are all common components, realizing the overall system circulation of the high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy.

[0035] In this embodiment, in the first liquid hydrogen evaporator 4, the second liquid hydrogen evaporator 5 and the cold energy recovery device 6, the cold energy of evaporation of high-pressure liquid hydrogen and the cold energy released by heating from the boiling point to room temperature are recovered by the circulating gas; according to the required temperature zone, the cold energy recovered from the circulating gas is successively used for hydrogen liquefaction pre-cooling and high-pressure hydrogen filling cooling in the filling cooler 31.

[0036] In this embodiment, the circulating gas is an inert gas; the inert gas may be nitrogen or argon.

[0037] In this embodiment, the filling cooling system 32 uses a vapor compression refrigeration system to cool the high-pressure hydrogen to -20°C; the filling cooler 31 uses the cold energy of the low-temperature circulating gas at the cold side outlet 12 of the second heat exchanger to cool the high-pressure hydrogen to -40°C.

[0038] In this embodiment, the boil-off gas BOG serving as the ejected fluid of the ejector 18 is drawn out from the top of the low-pressure liquid hydrogen storage tank 1; the high-pressure liquid hydrogen serving as the working fluid of the ejector 18 is composed of two parts: the high-pressure liquid hydrogen at the outlet of the sixth heat exchanger 16 and the high-pressure liquid hydrogen at the outlet of the low-pressure liquid hydrogen pump 33.

[0039] In this embodiment, the high-purity hydrogen required at the inlet of the hydrogen liquefaction system comes from hydrogen transported by a high-pressure pipeline, or is obtained by purifying and compressing low-pressure hydrogen. The hot runners of the first heat exchanger 11, the second heat exchanger 12, the third heat exchanger 13, the fourth heat exchanger 14, and the fifth heat exchanger 15 of the hydrogen liquefaction system are filled with an ortho-para-conversion catalyst, and a continuous conversion method is used to catalyze the conversion of ortho-hydrogen into para-hydrogen, and finally a high-pressure hydrogen stream with a para-hydrogen ratio of 95% is obtained at the outlet of the fifth heat exchanger 15.

[0040] In this embodiment, the liquid hydrogen in the medium-pressure liquid hydrogen storage tank 19 can be directly used for liquid hydrogen filling, or can be partially throttled by the throttle valve 34 and enter the low-pressure liquid hydrogen storage tank 1 to replenish the low-pressure liquid hydrogen therein.

[0041] Example 2 This embodiment provides an implementation method of a high-pressure gas-hydrogen-liquid hydrogen combined filling system for recovering liquid hydrogen cold energy, that is, a working method. Based on the high-pressure gas-hydrogen-liquid hydrogen combined filling system for recovering liquid hydrogen cold energy provided in Example 1, the specific implementation process is as follows: In the high-pressure gas hydrogen filling system of this embodiment, the liquid hydrogen in the low-pressure liquid hydrogen storage tank 1 enters the 45MPa low-temperature liquid hydrogen pump 2 and the 90MPa low-temperature liquid hydrogen pump 3 respectively, and enters the first liquid hydrogen evaporator 4 and the second liquid hydrogen evaporator 5 respectively after being pressurized to 45MPa and 90MPa by the low-temperature liquid hydrogen pumps. The high-pressure liquid hydrogen is gasified and heated to 213K in the first liquid hydrogen evaporator 4 and the second liquid hydrogen evaporator 5, and then further heated to 298.15K in the cold energy recovery device 6 and stored in the 45MPa high-pressure gas storage cylinder 7 and the 90MPa high-pressure gas storage cylinder 8 respectively. When 35MPa high-pressure hydrogen filling is required, the 45MPa high-pressure gas cylinder 7 opens the first outlet valve 9, and the high-pressure hydrogen enters the 35MPa filling cooling system 32, which adopts a vapor compression refrigeration cycle to cool the high-pressure hydrogen from the ambient temperature of 298.15 K to 273.15 K. After the high-pressure hydrogen is cooled to 273.15 K, 35MPa filling is performed. When 70MPa high-pressure hydrogen filling is required, the 90MPa high-pressure gas cylinder 8 opens the second outlet valve 10, and the high-pressure hydrogen enters the 70MPa filling cooler 31. The high-pressure hydrogen in the 70MPa filling cooler 31 is cooled to 233.15 K by the low-temperature circulating gas from the outlet of the second heat exchanger 12, and the high-pressure hydrogen at the outlet of the 70MPa filling cooler 31 is filled at 70 MPa.

[0042] In the liquid hydrogen cold energy recovery system with circulating gas cooling in this embodiment, the circulating gas compressor 29 pressurizes the circulating gas from 0.1 MPa to 0.2 MPa to overcome the pressure loss in the heat exchanger during the circulating gas circulation process. The high-pressure circulating gas at the outlet of the circulating gas compressor 29 is cooled to 300 K by the circulating gas cooler 30, and then enters the cold energy recovery device 6 to be cooled to 219 K by high-pressure liquid hydrogen. The circulating gas at the outlet of the cold energy recovery device 6 is divided into two streams by the splitter, with a mass ratio of 50.06% and 49.94% respectively, and enters the first liquid hydrogen evaporator 4 and the second liquid hydrogen evaporator 5 to recover liquid hydrogen cold energy respectively. The circulating gas at the outlet of the first liquid hydrogen evaporator 4 is cooled to 81.47 K, and then enters the third heat exchanger 13 to provide cold energy for hydrogen liquefaction. The circulating gas at the outlet of the second liquid hydrogen evaporator 5 is cooled to 87.85 K, and then mixed with the circulating gas at the outlet of the third heat exchanger 13 and enters the second heat exchanger 12. The low-temperature circulating gas that recovers the cold energy of liquid hydrogen exchanges heat with hydrogen in the third heat exchanger 13 and the second heat exchanger 12. The temperatures of the circulating gases at the outlets of the third heat exchanger 13 and the second heat exchanger 12 are respectively raised to 86.29K and 231K. The circulating gas at the outlet of the second heat exchanger 12 is divided into two streams by a flow splitter, with the mass proportions being 52.25% and 47.75% respectively. Stream 1 enters the first heat exchanger 11 to exchange heat with the high-pressure hydrogen at the inlet of the hydrogen liquefaction system, and stream 2 enters the 70MPa charging cooler 31 to provide cold energy for cooling the high-pressure hydrogen. The temperatures of the circulating gases at the outlets of the first heat exchanger 11 and the 70MPa charging cooler 31 are 279K and 296K respectively. The circulating gases at the outlets of the first heat exchanger 11 and the 70MPa charging cooler 31 are mixed and enter the circulating gas compressor 29 to form a circulating gas cycle.

[0043] In the hydrogen liquefaction system of this embodiment, the high-purity hydrogen required for hydrogen liquefaction comes from hydrogen transported by high-pressure pipelines, or is obtained by purifying and compressing low-pressure hydrogen. The liquid hydrogen obtained by the hydrogen liquefaction system can make up for the liquid hydrogen required for high-pressure hydrogen filling. Hydrogen liquefaction mainly consists of two parts: the precooling stage and the deep cooling stage. In the precooling stage, the hydrogen liquefaction system mainly relies on the liquid hydrogen cold energy recovered from the circulating gas to achieve cooling. The hydrogen liquefied stream exchanges heat with the low-temperature circulating gas in the first heat exchanger 11, the second heat exchanger 12, and the third heat exchanger 13, and is cooled to 268.7 K, 95 K, and 83.5 K in succession. In the deep cooling stage, the hydrogen liquefaction system mainly relies on the cold energy obtained by the expansion of low-temperature helium. The hydrogen liquefied stream exchanges heat with the expanded low-temperature helium in the fourth heat exchanger 14, the fifth heat exchanger 15, and the sixth heat exchanger 16, and is cooled to 53.15 K, 33.15 K, and 22.5 K in turn. The high-pressure liquid hydrogen at the outlet of the sixth heat exchanger 16 enters the ejector 18 as a working fluid. In the helium reverse Brayton cycle, the total pressure ratio of the helium compressor unit 21 is 10, a three-stage compression design is selected, and three-stage equal pressure ratio compression is adopted. The exhaust temperature of each compressor is 421.5 K, and the helium at the outlet of each compressor is cooled to 298.15 K by the after-stage cooler 22. The exhaust pressure of the last compressor is 1 MPa. The high-pressure helium at the outlet of the helium compressor unit 21 is divided into three streams by a flow divider, with mass proportions of 29.56%, 51.25% and 18.19% respectively, and enter the seventh heat exchanger 23, the eighth heat exchanger 24 and the ninth heat exchanger 25 respectively to exchange heat with the reflux helium, and are cooled to 77.9 K, 50 K and 34.01 K respectively, and then enter the first cryogenic helium expander 26, the second cryogenic helium expander 27 and the third cryogenic helium expander 28 respectively. The low-temperature helium at the outlet of the expander enters the fourth heat exchanger 14, the fifth heat exchanger 15 and the sixth heat exchanger 16 respectively. The low-temperature helium streams in the above three heat exchangers are heated to 76.4 K, 48.3 K and 32.0 K respectively after heat exchange with the hydrogen liquefaction streams. K, the helium at the outlets of the fourth heat exchanger 14, the fifth heat exchanger 15, and the sixth heat exchanger 16 flow into the seventh heat exchanger 23, the eighth heat exchanger 24, and the ninth heat exchanger 25 as reflux gas, respectively. The reflux gas at the outlets of the above three heat exchangers is heated to 297.3 K, and the reflux gas at the outlets of the three heat exchangers is mixed and enters the helium compressor unit 21 to realize helium circulation. In this embodiment, the high-pressure hydrogen flow channels of the first heat exchanger 11, the second heat exchanger 12, the third heat exchanger 13, the fourth heat exchanger 14, and the fifth heat exchanger 15 are filled with ortho-parahydrogen conversion catalysts, and the orthohydrogen is converted into parahydrogen in a continuous conversion manner, and finally a high-pressure hydrogen stream with a parahydrogen ratio of 95% is obtained at the outlet of the fifth heat exchanger 15.

[0044] The core component of the liquid hydrogen filling and BOG treatment system in this embodiment is the ejector 18. In this system, the low-pressure liquid hydrogen storage tank 1 is connected to the low-pressure liquid hydrogen pump 33. The low-pressure liquid hydrogen pump 33 pressurizes the liquid hydrogen to 2.5 MPa and mixes it with the high-pressure liquid hydrogen at the outlet of the sixth heat exchanger 16. The mixed stream enters the ejector 18 as the working fluid, and the BOG drawn from the top of the low-pressure liquid hydrogen storage tank 1 enters the ejector 18 as the ejected fluid. The BOG is recondensed in the ejector 18, and the liquid hydrogen at the outlet of the ejector 18 enters the medium-pressure liquid hydrogen storage tank 19 for temporary storage. The liquid hydrogen in the medium-pressure liquid hydrogen storage tank 19 can be directly used for liquid hydrogen filling after pressurization, or it can be partially throttled and depressurized by the throttle valve 34 and enter the low-pressure liquid hydrogen storage tank 1 to replenish the liquid hydrogen therein.

[0045] In order to further demonstrate the beneficial effects of this embodiment, Figure 1 The process simulation calculation was carried out, and the key operating parameters and key performance evaluation indicators are listed in Table 1. The ambient temperature was 298.15K, and the ambient pressure was 0.1MPa; the mass flow rates of 45MPa and 90MPa high-pressure hydrogen and the mass flow rates of liquefied hydrogen in the hydrogen liquefaction system were set to 100 kg / h, 100 kg / h, and 200 kg / h, respectively; nitrogen was used as the circulating gas, and the outlet pressure of the circulating gas compressor, the exhaust pressure of the helium compressor, and the outlet pressure of the cryogenic helium expander were set to 0.2 MPa, 1 MPa, and 0.1 MPa, respectively.

[0046] In this embodiment, the power of the 45MPa cryogenic liquid hydrogen pump for 35MPa high-pressure gas hydrogen filling is 19.29kW, and the 35MPa filling cooling system adopts a vapor compression refrigeration system with an average COP=3, with a power of 18.84kW; the power of the 90MPa cryogenic liquid hydrogen pump for 70MPa high-pressure gas hydrogen filling is 39.72kW. In this embodiment, the required circulating gas and helium mass flow rates are 3246 kg / h and 2113 kg / h, respectively. The ratio of the working fluid to the BOG mass flow rate of the ejector 18 is selected to be 7.5, the BOG processing flow rate is 40 kg / h, and the ejector outlet pressure is 0.74MPa. The main energy-consuming equipment of the hydrogen liquefaction system is the circulating gas compressor and the helium compressor. The sum of the power of the two is the energy consumption of the hydrogen liquefaction system. The unit mass hydrogen liquefaction energy consumption ratio is the ratio of the hydrogen liquefaction system energy consumption to the hydrogen liquefaction mass flow rate. In this embodiment, the power of the circulating gas compressor is 69.24 kW, the power of the helium compressor unit is 1125 kW, and the calculated specific energy consumption of hydrogen liquefaction is 5.972 kWh / kg.

[0047] Table 1 shows the key operating parameters and key performance evaluation indicators

[0048] In summary, the present invention provides a high-pressure gas hydrogen and liquid hydrogen combined filling system and method for recovering liquid hydrogen cold energy, which has the following advantages over existing filling measures: The high-pressure gas-hydrogen-liquid hydrogen joint filling system for recovering liquid hydrogen cold energy realizes the efficient and low-cost recovery and comprehensive application of liquid hydrogen cold capacity in liquid hydrogen filling stations through the circulating gas cooling technology. It not only uses the recovered cold energy for pre-cooling of hydrogen liquefaction and high-pressure hydrogen filling cooling, but also realizes low-energy self-replenishment of liquid hydrogen through the helium reverse Brayton cryogenic refrigeration system. At the same time, it uses the ejector to treat the boil-off gas at low cost, and innovatively proposes a high-efficiency joint filling scheme for high-pressure gas-hydrogen and liquid hydrogen, which integrates the functions of efficient recovery of liquid hydrogen cold energy, self-replenishment of liquid hydrogen, boil-off gas re-condensation, and cooling and filling of high-pressure gas-hydrogen, providing a new efficient and economical way for the comprehensive utilization of energy in liquid hydrogen filling stations.

[0049] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy, characterized in that: It includes high-pressure gas hydrogen filling system, liquid hydrogen filling and BOG treatment system, circulating gas-cooled liquid hydrogen cooling energy recovery system and hydrogen liquefaction system; The high-pressure gas hydrogen filling system is used to pressurize the liquid hydrogen output by the hydrogen liquefaction system to achieve high-pressure gas hydrogen filling; The liquid hydrogen filling and BOG treatment system is used to process the liquid hydrogen boil-off gas output by the hydrogen liquefaction system and realize liquid hydrogen filling; The circulating gas-cooled liquid hydrogen cold energy recovery system is used to realize liquid hydrogen cold energy recovery by exchanging heat between the circulating gas and the low-temperature and high-pressure liquid hydrogen in the high-pressure gas hydrogen filling system; The hydrogen liquefaction system is used to pre-cool the raw material high-purity hydrogen gas using the cold energy recovered by the liquid hydrogen cold energy recovery system with circulating gas cooling, and then complete the liquefaction of the raw material high-purity hydrogen gas to output liquid hydrogen; The liquid hydrogen filling and BOG treatment system comprises: an ejector (18) and a medium-pressure liquid hydrogen storage tank (19) connected to each other; The liquid hydrogen boil-off gas output by the hydrogen liquefaction system serves as the ejected fluid of the ejector (18); the hydrogen liquefaction system is connected to the working fluid inlet of the ejector (18) via a low-pressure liquid hydrogen pump (33); The liquid hydrogen boil-off gas is mixed with the low-pressure liquid hydrogen pressurized by the hydrogen liquefaction system through the ejector (18), and the liquid hydrogen boil-off gas enters the medium-pressure liquid hydrogen storage tank (19) after being condensed; The liquid hydrogen in the medium-pressure liquid hydrogen storage tank (19) is used for liquid hydrogen filling or, after being depressurized, provides liquid hydrogen supplementation for the hydrogen liquefaction system.

2. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 1 is characterized in that: The hydrogen liquefaction system comprises a low-pressure liquid hydrogen storage tank (1), a first heat exchanger (11), a second heat exchanger (12), a third heat exchanger (13), a fourth heat exchanger (14), a fifth heat exchanger (15), a sixth heat exchanger (16), a helium compressor unit (21), a stage aftercooler (22), a seventh heat exchanger (23), an eighth heat exchanger (24), a ninth heat exchanger (25), a first cryogenic helium expander (26), a second cryogenic helium expander (27) and a third cryogenic helium expander (28); The hot side inlet of the first heat exchanger (11) is connected to a raw material high-purity hydrogen source, and the hot side outlet of the first heat exchanger (11) is sequentially connected to the hot side inlet of the second heat exchanger (12), the hot side inlet of the third heat exchanger (13), the hot side inlet of the fourth heat exchanger (14), the hot side inlet of the fifth heat exchanger (15), the hot side inlet of the sixth heat exchanger (16), the first valve (17), and the working fluid inlet of the ejector (18); The medium-pressure liquid hydrogen storage tank (19) is connected to the low-pressure liquid hydrogen storage tank (1) via a throttle valve (34); The top of the low-pressure liquid hydrogen storage tank (1) is connected to the ejector (18); The low-pressure liquid hydrogen storage tank (1) is connected to the working fluid inlet of the ejector (18) through a third valve (35) and a low-pressure liquid hydrogen pump (33), and is also connected to the high-pressure gas hydrogen filling system; The high-pressure helium outlet of the helium compressor unit (21) is connected to the after-stage cooler (22), and the outlet of the after-stage cooler (22) is respectively connected to the hot side inlet of the seventh heat exchanger (23), the hot side inlet of the eighth heat exchanger (24), and the hot side inlet of the ninth heat exchanger (25); The hot side outlet of the seventh heat exchanger (23), the hot side outlet of the eighth heat exchanger (24), and the hot side outlet of the ninth heat exchanger (25) are respectively connected to the inlet of the first cryogenic helium expander (26), the inlet of the second cryogenic helium expander (27), and the inlet of the third cryogenic helium expander (28); The outlet of the first cryogenic helium expander (26), the outlet of the second cryogenic helium expander (27), and the outlet of the third cryogenic helium expander (28) are respectively connected to the cold side inlet of the fourth heat exchanger (14), the cold side inlet of the fifth heat exchanger (15), and the cold side inlet of the sixth heat exchanger (16); The cold side outlet of the fourth heat exchanger (14), the cold side outlet of the fifth heat exchanger (15), and the cold side outlet of the sixth heat exchanger (16) are respectively connected to the cold side inlet of the seventh heat exchanger (23), the cold side inlet of the eighth heat exchanger (24), and the cold side inlet of the ninth heat exchanger (25); The cold side outlet of the seventh heat exchanger (23), the cold side outlet of the eighth heat exchanger (24), and the cold side outlet of the ninth heat exchanger (25) are connected to the low-pressure inlet of the helium compressor unit (21).

3. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 2 is characterized in that: The hot runners of the first heat exchanger (11), the second heat exchanger (12), the third heat exchanger (13), the fourth heat exchanger (14), and the fifth heat exchanger (15) are all filled with ortho-parahydrogen conversion catalysts, and a continuous conversion method is used to catalyze the conversion of orthohydrogen into parahydrogen.

4. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 2 is characterized in that: The high-pressure gas hydrogen filling system comprises a first low-temperature liquid hydrogen pump (2) and a second low-temperature liquid hydrogen pump (3) respectively connected to the liquid hydrogen output end of the hydrogen liquefaction system; the first low-temperature liquid hydrogen pump (2) is connected in sequence to a first liquid hydrogen evaporator (4), a first high-pressure gas storage bottle (7) and a filling cooling system (32) through the liquid hydrogen cold energy recovery system cooled by the circulating gas; the second low-temperature liquid hydrogen pump (3) is connected in sequence to a second liquid hydrogen evaporator (5), a second high-pressure gas storage bottle (8) and a filling cooler (31) through the liquid hydrogen cold energy recovery system cooled by the circulating gas.

5. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 4 is characterized in that: in, The first cryogenic liquid hydrogen pump (2) adopts a 45MPa cryogenic liquid hydrogen pump, and the second cryogenic liquid hydrogen pump (3) adopts a 90MPa cryogenic liquid hydrogen pump; the first high-pressure gas storage cylinder (7) adopts a 45MPa high-pressure gas storage cylinder, and the second high-pressure gas storage cylinder (8) adopts a 90MPa high-pressure gas storage cylinder; the filling cooling system (32) adopts a 35MPa filling cooling system, and the filling cooler (31) adopts a 70MPa filling cooler (31).

6. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 5 is characterized in that: The 35MPa charging cooling system adopts a vapor compression refrigeration system.

7. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 4 is characterized in that: The circulating gas-cooled liquid hydrogen cold energy recovery system comprises a circulating gas compressor (29), a circulating gas cooler (30) and a cold energy recovery device (6); the circulating gas outlet of the circulating gas compressor (29) is connected to the inlet of the circulating gas cooler (30), the circulating gas cooler (30) outlet is connected to the hot side inlet of the cold energy recovery device (6), and the hot side outlet of the cold energy recovery device (6) is respectively connected to the hot side inlet of the first liquid hydrogen evaporator (4) and the hot side inlet of the second liquid hydrogen evaporator (5); the first liquid hydrogen evaporator (4) is connected to the first low-temperature liquid hydrogen pump (2), and the second liquid hydrogen evaporator (5) is connected to the second low-temperature liquid hydrogen pump (3); the hydrogen liquid The cold side outlet of the first heat exchanger (11) of the liquefaction system is connected to the circulating gas inlet of the circulating gas compressor (29); the cold side outlet of the second heat exchanger (12) is connected to the cold side inlet of the filling cooler (31); the cold side outlet of the filling cooler (31) is connected to the circulating gas inlet of the circulating gas compressor (29); wherein the circulating gas, after being pressurized by the circulating gas compressor (29), enters the cold energy recovery device (6), the first liquid hydrogen evaporator (4), and the second liquid hydrogen evaporator (5) to recover the cold energy of liquid hydrogen evaporation, and then enters the hydrogen liquefaction system and the filling cooler (31) to provide cold energy for hydrogen liquefaction precooling and high-pressure hydrogen filling cooling.

8. The high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 7 is characterized in that: The circulating gas of the circulating gas compressor (29) is an inert gas, which is nitrogen or argon.

9. A working method of a high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy, characterized in that: A high-pressure gas-hydrogen-liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to any one of claims 1 to 8, comprising: The hydrogen liquefaction system uses the cold energy recovered from the circulating gas to pre-cool the raw high-purity hydrogen, and then liquefies the raw high-purity hydrogen to output liquid hydrogen; The high-pressure gas hydrogen filling system pressurizes the liquid hydrogen output by the hydrogen liquefaction system to achieve high-pressure gas hydrogen filling; The liquid hydrogen filling and BOG treatment system processes the liquid hydrogen boil-off gas output by the hydrogen liquefaction system and realizes liquid hydrogen filling; The circulating gas-cooled liquid hydrogen cold energy recovery system realizes liquid hydrogen cold energy recovery through heat exchange between the circulating gas and the low-temperature and high-pressure liquid hydrogen in the high-pressure gas hydrogen filling system; The low-pressure liquid hydrogen pump (33) pressurizes the low-pressure liquid hydrogen in the hydrogen liquefaction system; The liquid hydrogen boil-off gas outputted from the hydrogen liquefaction system is mixed with the low-pressure liquid hydrogen pressurized by the hydrogen liquefaction system through an ejector, and the liquid hydrogen boil-off gas is condensed and enters the medium-pressure liquid hydrogen storage tank (19); Liquid hydrogen in the medium-pressure liquid hydrogen storage tank (19) is used for liquid hydrogen filling, or the liquid hydrogen is depressurized to replenish liquid hydrogen for the hydrogen liquefaction system.

10. The working method of the high-pressure gas hydrogen and liquid hydrogen combined filling system for recovering liquid hydrogen cold energy according to claim 9 is characterized in that: After high-purity hydrogen enters the hydrogen liquefaction system, it is cooled by six-stage heat exchangers. The low-temperature and high-pressure liquid hydrogen at the hot side outlet of the hydrogen liquefaction system enters the ejector (18) as a working fluid, and the evaporated gas is recondensed in the ejector (18) and then enters the medium-pressure liquid hydrogen storage tank (19) for storage.

Images