Liquid hydrogen pressurization system and liquid hydrogen pressurization method

Abstract

The invention provides a liquid hydrogen pressurization system. Comprising a liquid hydrogen storage tank (1), a throttling liquid hydrogen pipeline (2), a throttling valve (3), a throttling liquid hydrogen pipeline (4), a supercooling heat exchanger (5), a throttling hydrogen pipeline (6), a liquid hydrogen booster pump (7), a high-pressure and low-temperature hydrogen pipeline (9), a low-temperature and high-pressure hydrogen application system (10), a hydrogen discharge pipeline (11), a hydrogen discharge system (12), a supercooling liquid hydrogen pipeline (14), a liquid hydrogen pipeline (15), a low-temperature and high-pressure one-way valve (16), a discharge one-way valve (17) and a liquid hydrogen storage tank outlet switch valve (18). A small amount of liquid hydrogen is used for throttling and cooling, saturated liquid hydrogen entering an inlet of the liquid hydrogen booster pump (7) is supercooled by 0.5 K to 1 K, the gas content of inlet liquid of the liquid hydrogen booster pump (7) can be greatly reduced, even full-liquid suction can be achieved, the piston volume efficiency of the liquid hydrogen booster pump (7) is improved, and compression power consumption is reduced. In addition, the invention further provides a liquid hydrogen pressurization method.

Description

Technical Field

[0001] The present application relates to the field of refrigeration and cryogenic technology, and in particular to a liquid hydrogen pressurization system and a liquid hydrogen pressurization method. Background Art

[0002] Liquid hydrogen is one of the important forms of hydrogen energy utilization. A liquid hydrogen refueling station is a facility that effectively utilizes liquid hydrogen and can provide fuel for hydrogen fuel vehicles. In mature processes abroad, gaseous hydrogen is usually reduced to 20K for liquefaction in a liquid hydrogen plant, and then transported to a liquid hydrogen tank truck through a cryogenic transmission pipeline. The liquid hydrogen is then transported to a hydrogen refueling station by a liquid hydrogen tank truck, and then transported to a liquid hydrogen storage tank in the station through a cryogenic transmission pipeline and stored. At present, liquid hydrogen storage and gas hydrogen refueling stations need to provide 35 / 70MPa high-pressure gas hydrogen to hydrogen fuel cell vehicles, and the power consumption required for liquid compression is lower than that for gas compression. Therefore, liquid hydrogen refueling stations usually use liquid hydrogen booster pumps to pressurize 1-3bar liquid hydrogen in the liquid hydrogen storage tank to the pressure required for refueling, and then after gasification and rewarming, they reach the temperature and pressure conditions required for refueling.

[0003] The liquid hydrogen booster pump used in the liquid hydrogen refueling station is a reciprocating piston pump. The liquid hydrogen at the inlet of the liquid hydrogen pump is usually in a saturated state and enters the compression chamber directly through the inlet valve. The cross-sectional area at the inlet valve becomes smaller, the flow rate increases, the dynamic pressure increases and the static pressure decreases. At the same time, the existence of flow loss makes the pressure entering the compression chamber lower than the saturation pressure, and the liquid hydrogen is partially vaporized, resulting in a decrease in the amount of liquid entering the compression chamber, reducing the volumetric efficiency of the pump. In severe cases, the pump cannot absorb liquid hydrogen. Summary of the invention

[0004] In view of this, it is necessary to provide a liquid hydrogen pressurizing system and a liquid hydrogen pressurizing method with high pump volumetric efficiency in order to address the technical defect of low pump volumetric efficiency in the prior art.

[0005] To solve the above problems, this application adopts the following technical solutions:

[0006] One of the purposes of the present application is to provide a liquid hydrogen pressurizing system, comprising: a liquid hydrogen storage tank (1), a throttling liquid hydrogen pipeline (2), a throttling valve (3), a throttling liquid hydrogen pipeline (4), a subcooling heat exchanger (5), a throttling hydrogen pipeline (6), a liquid hydrogen booster pump (7), a high-pressure low-temperature hydrogen pipeline (9), a low-temperature and high-pressure hydrogen application system (10), a hydrogen discharge pipeline (11), a hydrogen discharge system (12), a subcooling liquid hydrogen pipeline (14), a liquid hydrogen pipeline (15), a low-temperature and high-pressure one-way valve (16), a discharge one-way valve (17) and a liquid hydrogen storage tank outlet switch valve (18), wherein:

[0007] The liquid hydrogen stored in the liquid hydrogen storage tank (1) is discharged from the liquid outlet, a part of the liquid hydrogen enters the supercooling heat exchanger (5) through the liquid hydrogen pipeline (15) and obtains supercooled liquid hydrogen through heat exchange, the supercooled liquid hydrogen enters the liquid hydrogen booster pump (7) through the supercooled liquid hydrogen pipeline (14) and forms high-pressure and low-temperature hydrogen in the liquid hydrogen booster pump (7), and the high-pressure and low-temperature hydrogen enters the low-temperature and high-pressure hydrogen application system (10) through the high-pressure and low-temperature hydrogen pipeline (9);

[0008] Another part of the liquid hydrogen passes through the throttling liquid hydrogen pipeline (2) and enters the throttling valve (3) to be throttled and form low-temperature saturated gas-liquid two-phase hydrogen. The gas-liquid two-phase hydrogen enters the supercooling heat exchanger (5). When the supercooling heat exchanger (5) supercools the liquid hydrogen in the liquid hydrogen pipeline (15), the liquid phase hydrogen in the gas-liquid two-phase hydrogen absorbs heat and becomes gaseous hydrogen. After absorbing heat and heating in the supercooling heat exchanger (5), the gaseous hydrogen enters the throttling hydrogen pipeline (6) and then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) to cool the motor. After the gaseous hydrogen is further heated by the motor cooling unit (19), it is discharged through the hydrogen discharge pipeline (11) and enters the hydrogen discharge system (12).

[0009] In some of the embodiments, a booster pump cooling jacket (8) is further included, and the booster pump cooling jacket (8) is a cooling circuit integrated in the housing of the liquid hydrogen booster pump (7).

[0010] In some of the embodiments, the gaseous hydrogen absorbs heat and heats up in the subcooling heat exchanger (5) before entering the throttling hydrogen pipeline (6), and then the gaseous hydrogen enters the booster pump cooling jacket (8) and further absorbs the heat generated by the compression of the liquid hydrogen booster pump (7) and heats up further before entering the motor cooling unit (19) of the liquid hydrogen booster pump (7) through the hydrogen pipeline (13).

[0011] In some of the embodiments, the liquid hydrogen storage tank (1) is a cryogenic storage tank with a vacuum multi-layer insulation structure, and the working pressure is in the range of 1 to 5 bar.

[0012] In some of the embodiments, the throttling liquid hydrogen pipeline (2), the throttling liquid hydrogen pipeline (4), the throttling hydrogen gas pipeline (6), the hydrogen gas pipeline (13), the subcooled liquid hydrogen pipeline (14) and the liquid hydrogen pipeline (15) are all cryogenic fluid transmission pipelines with a vacuum multi-layer insulation structure.

[0013] In some embodiments, the vacuum multi-layer thermal insulation structure cryogenic fluid transmission pipeline is a metal hard pipe or a metal soft pipe, and a cryogenic joint can be installed in the middle of the vacuum multi-layer thermal insulation structure cryogenic fluid transmission pipeline as needed.

[0014] In some of the embodiments, the throttle valve (3) is a cryogenic throttle valve that uses liquid hydrogen temperature. The cryogenic throttle valve is manual, pneumatic or electric, and is an explosion-proof structure that complies with hydrogen environments.

[0015] In some of the embodiments, the subcooling heat exchanger (5) is a two-stream low-temperature heat exchanger in the form of a plate-fin type, a shell and tube type, or a sleeve and tube type, and the material of the subcooling heat exchanger (5) is aluminum.

[0016] In some of the embodiments, the liquid hydrogen booster pump (7) is a piston-type single-stage or multi-stage reciprocating booster pump, which can boost the inlet pressure in the range of 1 to 3 bar to various pressures below 90 MPa.

[0017] In some of the embodiments, the low-temperature and high-pressure hydrogen application system (10) includes a high-pressure gasifier, a high-pressure gas storage tank and a hydrogenator, the hydrogen exhaust pipeline (11) is a single-layer pipeline at room temperature, and the hydrogen exhaust system (12) is a hydrogen exhaust system of a liquid hydrogen refueling station.

[0018] The second object of the present application is to provide a liquid hydrogen pressurizing method of the liquid hydrogen pressurizing system, comprising the following steps:

[0019] The liquid hydrogen stored in the liquid hydrogen storage tank (1) is discharged from the liquid outlet, a part of the liquid hydrogen enters the supercooling heat exchanger (5) through the liquid hydrogen pipeline (15) and obtains supercooled liquid hydrogen through heat exchange, the supercooled liquid hydrogen enters the liquid hydrogen booster pump (7) through the supercooled liquid hydrogen pipeline (14) and forms high-pressure and low-temperature hydrogen in the liquid hydrogen booster pump (7), and the high-pressure and low-temperature hydrogen enters the low-temperature and high-pressure hydrogen application system (10) through the high-pressure and low-temperature hydrogen pipeline (9);

[0020] Another part of the liquid hydrogen passes through the throttling liquid hydrogen pipeline (2) and enters the throttling valve (3) to be throttled and form low-temperature saturated gas-liquid two-phase hydrogen. The gas-liquid two-phase hydrogen enters the supercooling heat exchanger (5). When the supercooling heat exchanger (5) supercools the liquid hydrogen in the liquid hydrogen pipeline (15), the liquid phase hydrogen in the gas-liquid two-phase hydrogen absorbs heat and becomes gaseous hydrogen. After absorbing heat and heating in the supercooling heat exchanger (5), the gaseous hydrogen enters the throttling hydrogen pipeline (6) and then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) to cool the motor. After the gaseous hydrogen is further heated by the motor cooling unit (19), it is discharged through the hydrogen discharge pipeline (11) and enters the hydrogen discharge system (12).

[0021] In some embodiments, the following steps are also included:

[0022] The gaseous hydrogen absorbs heat and is heated in the subcooling heat exchanger (5) before entering the throttling hydrogen pipeline (6). Subsequently, the gaseous hydrogen enters the booster pump cooling jacket (8) and further absorbs the heat generated by the compression of the liquid hydrogen booster pump (7) and is further heated. The gaseous hydrogen then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) through the hydrogen pipeline (13).

[0023] This application adopts the above technical solution, and its beneficial effects are as follows:

[0024] The liquid hydrogen boosting system and liquid hydrogen boosting method provided in the present application use a small amount of liquid hydrogen for throttling and cooling to supercool the saturated liquid hydrogen entering the inlet of the liquid hydrogen boosting pump (7) by 0.5K to 1K, so that the gas content of the liquid inlet of the liquid hydrogen boosting pump (7) can be greatly reduced or even all liquid can be inhaled, thereby improving the piston volumetric efficiency of the liquid hydrogen boosting pump (7) and reducing compression power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic diagram of the structure of the liquid hydrogen boosting system provided in Example 1 of the present invention.

[0027] Figure 2 This is a schematic diagram of the structure of the liquid hydrogen boosting system provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0029] In the description of the present application, it should be understood that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0031] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0032] Example 1

[0033] See also Figure 1 , which is a schematic diagram of the structure of the liquid hydrogen boosting system provided in this embodiment 1, comprising: a liquid hydrogen storage tank (1), a throttling liquid hydrogen pipeline (2), a throttling valve (3), a throttling liquid hydrogen pipeline (4), a subcooling heat exchanger (5), a throttling hydrogen pipeline (6), a liquid hydrogen boosting pump (7), a high-pressure low-temperature hydrogen pipeline (9), a low-temperature high-pressure hydrogen application system (10), a hydrogen discharge pipeline (11), a hydrogen discharge system (12), a subcooling liquid hydrogen pipeline (14), a liquid hydrogen pipeline (15), a low-temperature high-pressure check valve (16), a discharge check valve (17) and a liquid hydrogen storage tank outlet switch valve (18). The following describes in detail the connection relationship of each component and its implementation method.

[0034] In this embodiment, the liquid hydrogen storage tank (1) is a cryogenic storage tank with a vacuum multi-layer insulation structure, and the working pressure is in the range of 1 to 5 bar.

[0035] In this embodiment, the throttling liquid hydrogen pipeline (2), the throttling liquid hydrogen pipeline (4), the throttling hydrogen gas pipeline (6), the hydrogen gas pipeline (13), the supercooled liquid hydrogen pipeline (14) and the liquid hydrogen pipeline (15) are all cryogenic fluid transmission pipelines with a vacuum multi-layer insulation structure.

[0036] In this embodiment, the throttling liquid hydrogen pipeline (2), the throttling valve (3), the throttling liquid hydrogen pipeline (4), the subcooling heat exchanger (5), the throttling hydrogen pipeline (6) and the booster pump cooling jacket (8) constitute the liquid inlet subcooling system of the liquid hydrogen booster pump (7), so that the liquid hydrogen inlet of the liquid hydrogen booster pump (7) is subcooled by 0.5K to 1K.

[0037] In this embodiment, the vacuum multi-layer thermal insulation structure cryogenic fluid transmission pipeline is a metal hard pipe or a metal soft pipe, and a cryogenic joint can be installed in the middle of the vacuum multi-layer thermal insulation structure cryogenic fluid transmission pipeline as needed.

[0038] In this embodiment, the throttle valve (3) is a cryogenic throttle valve that uses liquid hydrogen temperature. The cryogenic throttle valve is manual, pneumatic or electric, and is an explosion-proof structure that meets the requirements of a hydrogen environment.

[0039] In this embodiment, the subcooling heat exchanger (5) is a two-stream low-temperature heat exchanger in the form of a plate-fin type, a shell and tube type, or a sleeve and tube type, and the material of the subcooling heat exchanger (5) is aluminum.

[0040] In this embodiment, the liquid hydrogen booster pump (7) is a piston-type single-stage or multi-stage reciprocating booster pump, which can boost the inlet pressure in the range of 1 to 3 bar to various pressures below 90 MPa.

[0041] In this embodiment, the low temperature and high pressure hydrogen application system (10) comprises a high pressure gasifier, a high pressure gas storage tank and a hydrogenator. The hydrogen discharge pipeline (11) is a single layer pipeline at room temperature. The hydrogen discharge system (12) is a hydrogen discharge system of a liquid hydrogen refueling station.

[0042] The liquid hydrogen boosting system provided in the above-mentioned embodiment 1 of the present application works as follows:

[0043] The liquid hydrogen stored in the liquid hydrogen storage tank (1) is discharged from the liquid outlet, a part of the liquid hydrogen enters the supercooling heat exchanger (5) through the liquid hydrogen pipeline (15) and obtains supercooled liquid hydrogen through heat exchange, the supercooled liquid hydrogen enters the liquid hydrogen booster pump (7) through the supercooled liquid hydrogen pipeline (14) and forms high-pressure and low-temperature hydrogen in the liquid hydrogen booster pump (7), and the high-pressure and low-temperature hydrogen enters the low-temperature and high-pressure hydrogen application system (10) through the high-pressure and low-temperature hydrogen pipeline (9);

[0044] Another part of the liquid hydrogen passes through the throttling liquid hydrogen pipeline (2) and enters the throttling valve (3) to be throttled and form low-temperature saturated gas-liquid two-phase hydrogen. The gas-liquid two-phase hydrogen enters the supercooling heat exchanger (5). When the supercooling heat exchanger (5) supercools the liquid hydrogen in the liquid hydrogen pipeline (15), the liquid phase hydrogen in the gas-liquid two-phase hydrogen absorbs heat and becomes gaseous hydrogen. After absorbing heat and heating in the supercooling heat exchanger (5), the gaseous hydrogen enters the throttling hydrogen pipeline (6) and then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) to cool the motor. After the gaseous hydrogen is further heated by the motor cooling unit (19), it is discharged through the hydrogen discharge pipeline (11) and enters the hydrogen discharge system (12).

[0045] The liquid hydrogen boosting system provided in Example 1 of the present application uses a small amount of liquid hydrogen for throttling and cooling to supercool the saturated liquid hydrogen entering the inlet of the liquid hydrogen boosting pump (7) by 0.5K to 1K, so that the gas content of the liquid inlet of the liquid hydrogen boosting pump (7) can be greatly reduced or even all liquid can be inhaled, thereby improving the piston volumetric efficiency of the liquid hydrogen boosting pump (7) and reducing compression power consumption.

[0046] Example 2

[0047] See also Figure 2 , which is a schematic diagram of the structure of the liquid hydrogen boosting system provided in Example 2 of the present application, comprising: a liquid hydrogen storage tank (1), a throttling liquid hydrogen pipeline (2), a throttling valve (3), a throttling liquid hydrogen pipeline (4), a subcooling heat exchanger (5), a throttling hydrogen pipeline (6), a liquid hydrogen boosting pump (7), a boosting pump cooling jacket (8), a high-pressure low-temperature hydrogen pipeline (9), a low-temperature high-pressure hydrogen application system (10), a hydrogen discharge pipeline (11), a hydrogen discharge system (12), a hydrogen pipeline (13), a subcooling liquid hydrogen pipeline (14), a liquid hydrogen pipeline (15), a low-temperature high-pressure check valve (16), a discharge check valve (17) and a liquid hydrogen storage tank outlet switch valve (18). The following describes in detail the connection relationship of each component and its implementation method.

[0048] The difference from Example 1 is that this embodiment also includes a boost pump cooling jacket (8), and the boost pump cooling jacket (8) is a cooling circuit integrated in the casing of the liquid hydrogen boost pump (7). The specific implementation methods of other components can be found in Example 1 and will not be repeated here.

[0049] The liquid hydrogen boosting system provided in the above-mentioned embodiment 2 of the present application works as follows:

[0050] The liquid hydrogen stored in the liquid hydrogen storage tank (1) is discharged from the liquid outlet, a part of the liquid hydrogen enters the supercooling heat exchanger (5) through the liquid hydrogen pipeline (15) and obtains supercooled liquid hydrogen through heat exchange, the supercooled liquid hydrogen enters the liquid hydrogen booster pump (7) through the supercooled liquid hydrogen pipeline (14) and forms high-pressure and low-temperature hydrogen in the liquid hydrogen booster pump (7), and the high-pressure and low-temperature hydrogen enters the low-temperature and high-pressure hydrogen application system (10) through the high-pressure and low-temperature hydrogen pipeline (9);

[0051] Another part of the liquid hydrogen passes through the throttling liquid hydrogen pipeline (2) and enters the throttling valve (3) to be throttled and form low-temperature saturated gas-liquid two-phase hydrogen. The gas-liquid two-phase hydrogen enters the subcooling heat exchanger (5). When the subcooling heat exchanger (5) subcools the liquid hydrogen in the liquid hydrogen pipeline (15), the liquid phase hydrogen in the gas-liquid two-phase hydrogen absorbs heat and becomes gaseous hydrogen. The gaseous hydrogen absorbs heat and heats up in the subcooling heat exchanger (5) and enters the throttling hydrogen pipeline (6). Subsequently, the gaseous hydrogen enters the booster pump cooling jacket (8) and further absorbs the heat generated by the compression of the liquid hydrogen booster pump (7) and further heats up. Then, the gaseous hydrogen enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) through the hydrogen pipeline (13). After the gaseous hydrogen is further heated by the motor cooling unit (19), it is discharged through the hydrogen discharge pipeline (11) and enters the hydrogen discharge system (12).

[0052] The liquid hydrogen boosting system provided in Example 2 of the present application uses a small amount of liquid hydrogen for throttling and cooling to supercool the saturated liquid hydrogen entering the inlet of the liquid hydrogen boosting pump (7) by 0.5K to 1K, which can greatly reduce the gas content of the liquid inlet of the liquid hydrogen boosting pump (7) or even allow full liquid to be inhaled, thereby improving the piston volumetric efficiency of the liquid hydrogen boosting pump (7) and reducing compression power consumption. It can be understood that the various technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above are only preferred embodiments of the present application, and only specifically describe the technical principles of the present application. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application, and other specific implementation methods of the present application that can be associated with the technicians in this field without creative work, should be included in the scope of protection of the present application.

Claims

1. A liquid hydrogen pressurizing system, characterized in that: include: Liquid hydrogen storage tank (1), throttling liquid hydrogen pipeline (2), throttling valve (3), throttling liquid hydrogen pipeline (4), subcooling heat exchanger (5), throttling hydrogen pipeline (6), liquid hydrogen booster pump (7), high-pressure low-temperature hydrogen pipeline (9), low-temperature high-pressure hydrogen application system (10), hydrogen discharge pipeline (11), hydrogen discharge system (12), subcooling liquid hydrogen pipeline (14), liquid hydrogen pipeline (15), low-temperature high-pressure check valve (16), discharge check valve (17) and liquid hydrogen storage tank outlet switch valve (18), wherein: The liquid hydrogen stored in the liquid hydrogen storage tank (1) is discharged from the liquid outlet, a part of the liquid hydrogen enters the supercooling heat exchanger (5) through the liquid hydrogen pipeline (15) and obtains supercooled liquid hydrogen through heat exchange, the supercooled liquid hydrogen enters the liquid hydrogen booster pump (7) through the supercooled liquid hydrogen pipeline (14) and forms high-pressure and low-temperature hydrogen in the liquid hydrogen booster pump (7), and the high-pressure and low-temperature hydrogen enters the low-temperature and high-pressure hydrogen application system (10) through the high-pressure and low-temperature hydrogen pipeline (9); Another part of the liquid hydrogen passes through the throttling liquid hydrogen pipeline (2) and enters the throttling valve (3) to be throttled and form low-temperature saturated gas-liquid two-phase hydrogen. The gas-liquid two-phase hydrogen enters the supercooling heat exchanger (5). When the supercooling heat exchanger (5) supercools the liquid hydrogen in the liquid hydrogen pipeline (15), the liquid phase hydrogen in the gas-liquid two-phase hydrogen absorbs heat and becomes gaseous hydrogen. After absorbing heat and heating in the supercooling heat exchanger (5), the gaseous hydrogen enters the throttling hydrogen pipeline (6) and then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) to cool the motor. After the gaseous hydrogen is further heated by the motor cooling unit (19), it is discharged through the hydrogen discharge pipeline (11) and enters the hydrogen discharge system (12).

2. The liquid hydrogen pressurizing system according to claim 1, characterized in that: It also includes a booster pump cooling jacket (8), which is a cooling circuit integrated in the housing of the liquid hydrogen booster pump (7).

3. The liquid hydrogen pressurizing system according to claim 2, characterized in that: The gaseous hydrogen absorbs heat and is heated in the subcooling heat exchanger (5) before entering the throttling hydrogen pipeline (6). Subsequently, the gaseous hydrogen enters the booster pump cooling jacket (8) and further absorbs the heat generated by the compression of the liquid hydrogen booster pump (7) and is further heated. The gaseous hydrogen then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) through the hydrogen pipeline (13).

4. The liquid hydrogen pressurizing system according to claim 1, characterized in that: The liquid hydrogen storage tank (1) is a low-temperature storage tank with a vacuum multi-layer insulation structure, and the working pressure is in the range of 1 to 5 bar.

5. The liquid hydrogen pressurizing system according to claim 1, characterized in that: The throttling liquid hydrogen pipeline (2), the throttling liquid hydrogen pipeline (4), the throttling hydrogen gas pipeline (6), the hydrogen gas pipeline (13), the supercooled liquid hydrogen pipeline (14) and the liquid hydrogen pipeline (15) are all cryogenic fluid transmission pipelines using a vacuum multi-layer thermal insulation structure.

6. The liquid hydrogen pressurizing system according to claim 5, characterized in that: The vacuum multi-layer thermal insulation structure cryogenic fluid transmission pipeline is a metal hard pipe or a metal hose, and a cryogenic joint can be installed in the middle of the vacuum multi-layer thermal insulation structure cryogenic fluid transmission pipeline as needed.

7. The liquid hydrogen pressurizing system according to claim 1, characterized in that: The throttle valve (3) is a low-temperature throttle valve that uses liquid hydrogen temperature. The low-temperature throttle valve is manual, pneumatic or electric, and is an explosion-proof structure that meets the requirements of a hydrogen environment.

8. The liquid hydrogen pressurizing system according to claim 1, characterized in that: The subcooling heat exchanger (5) is a two-stream low-temperature heat exchanger in the form of a plate-fin type, a shell-and-tube type, or a sleeve-and-tube type. The material of the subcooling heat exchanger (5) is aluminum.

9. The liquid hydrogen pressurizing system according to claim 1, characterized in that: The liquid hydrogen booster pump (7) is a piston-type single-stage or multi-stage reciprocating booster pump, which can boost the inlet pressure within the range of 1 to 3 bar to various pressures below 90 MPa.

10. The liquid hydrogen pressurizing system according to claim 1, characterized in that: The low-temperature and high-pressure hydrogen application system (10) comprises a high-pressure gasifier, a high-pressure gas storage tank and a hydrogenator, the hydrogen exhaust pipeline (11) is a single-layer pipeline at room temperature, and the hydrogen exhaust system (12) is a hydrogen exhaust system of a liquid hydrogen refueling station.

11. A liquid hydrogen pressurizing method of a liquid hydrogen pressurizing system according to claim 1, characterized in that: The steps include: The liquid hydrogen stored in the liquid hydrogen storage tank (1) is discharged from the liquid outlet, a part of the liquid hydrogen enters the supercooling heat exchanger (5) through the liquid hydrogen pipeline (15) and obtains supercooled liquid hydrogen through heat exchange, the supercooled liquid hydrogen enters the liquid hydrogen booster pump (7) through the supercooled liquid hydrogen pipeline (14) and forms high-pressure and low-temperature hydrogen in the liquid hydrogen booster pump (7), and the high-pressure and low-temperature hydrogen enters the low-temperature and high-pressure hydrogen application system (10) through the high-pressure and low-temperature hydrogen pipeline (9); Another part of the liquid hydrogen passes through the throttling liquid hydrogen pipeline (2) and enters the throttling valve (3) to be throttled and form low-temperature saturated gas-liquid two-phase hydrogen. The gas-liquid two-phase hydrogen enters the supercooling heat exchanger (5). When the supercooling heat exchanger (5) supercools the liquid hydrogen in the liquid hydrogen pipeline (15), the liquid phase hydrogen in the gas-liquid two-phase hydrogen absorbs heat and becomes gaseous hydrogen. After absorbing heat and heating in the supercooling heat exchanger (5), the gaseous hydrogen enters the throttling hydrogen pipeline (6) and then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) to cool the motor. After the gaseous hydrogen is further heated by the motor cooling unit (19), it is discharged through the hydrogen discharge pipeline (11) and enters the hydrogen discharge system (12).

12. The liquid hydrogen pressurizing method of the liquid hydrogen pressurizing system according to claim 1, characterized in that: The following steps are also included: The gaseous hydrogen absorbs heat and is heated in the subcooling heat exchanger (5) before entering the throttling hydrogen pipeline (6). Subsequently, the gaseous hydrogen enters the booster pump cooling jacket (8) and further absorbs the heat generated by the compression of the liquid hydrogen booster pump (7) and is further heated. The gaseous hydrogen then enters the motor cooling unit (19) of the liquid hydrogen booster pump (7) through the hydrogen pipeline (13).

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