Indirect heat exchange liquid hydrogen vaporization system and method

Abstract

The present invention discloses an indirect heat exchange liquid hydrogen vaporization system and method, and relates to the field of liquid hydrogen vaporization equipment. The system includes a temperature-controlled vaporizer, a seawater pipeline, a liquid hydrogen pipeline, a hydrogen branch and a working fluid pipeline; the seawater pipeline is sequentially connected to a seawater stop valve, a seawater pump, a first channel of a hydrogen temperature riser and a liquid phase working fluid area of ​​the temperature-controlled vaporizer; the liquid hydrogen pipeline is connected to a temperature sensor after heat exchange with the gas phase working fluid area of ​​the temperature-controlled vaporizer, and then divided into two branches; the liquid hydrogen pipeline located upstream of the temperature-controlled vaporizer is also provided with a hydrogen branch; a working fluid pipeline inlet and a working fluid pipeline outlet are provided at the gas phase working fluid area of ​​the temperature-controlled vaporizer, and the working fluid pipeline outlet is refluxed to the working fluid pipeline outlet through the working fluid pipeline. The present invention uses seawater as a heat source for liquid hydrogen vaporization, improves the efficiency of liquid hydrogen vaporization, and reduces the volume of the liquid hydrogen vaporizer. At the same time, an intermediate heat exchange medium and a pressure control method are used to overcome typical problems such as seawater freezing, and achieve specific hydrogen temperature control.

Description

Technical Field

[0001] The present invention relates to the field of liquid hydrogen vaporization equipment, and in particular to an indirect heat exchange type liquid hydrogen vaporization system and method. Background Art

[0002] Compared with the use of high-pressure gaseous hydrogen, liquid hydrogen has the characteristics of high efficiency and controllability, low pollution, and stable quality. It has the advantages of high efficiency and low cost in storage and transportation. In terms of application, it has the advantages of small footprint of hydrogen refueling stations, low pressure, flexible hydrogen supply methods, and higher purity. The maritime transportation of liquid hydrogen must be one of the main ways of large-scale transportation of hydrogen, and it is necessary to build a safe and cheap global hydrogen transportation system. Studies predict that the global demand for low-carbon hydrogen will reach 530 million tons in 2050, of which nearly 150 million tons will be traded in the shipping market. Therefore, it is particularly urgent to develop special offshore liquid hydrogen equipment for liquid hydrogen transport ships or loading and unloading terminals.

[0003] During the marine transportation of liquid hydrogen, a stable supply of hydrogen is often required as an energy source for equipment such as fuel cells, so a vaporizer is needed to vaporize part of the liquid hydrogen. However, due to the low temperature of liquid hydrogen, conventional air-type vaporizers are bulky and not conducive to marine transportation applications. Relatively speaking, seawater temperature is relatively stable, with large heat capacity, and is an inexhaustible heat source. However, the use of seawater as a heat source for liquid hydrogen vaporization is also accompanied by heat transfer deterioration phenomena such as icing and scaling, and a liquid hydrogen vaporizer with high heat transfer efficiency needs to be designed. Summary of the invention

[0004] The purpose of the present invention is to provide an indirect heat exchange seawater vaporization system and method, which utilizes seawater as a heat source for liquid hydrogen vaporization, improves the efficiency of liquid hydrogen vaporization, and reduces the volume of the liquid hydrogen vaporizer. At the same time, an intermediate heat exchange medium and a pressure control method are used to overcome typical problems such as seawater freezing, and specific hydrogen temperature control is achieved according to the subsequent hydrogen temperature requirements.

[0005] The present invention intends to achieve the purpose of the present invention by the following technical scheme:

[0006] In a first aspect, the present invention provides an indirect heat exchange liquid hydrogen vaporization system, comprising a temperature-controlled vaporizer, a seawater pipeline, a liquid hydrogen pipeline, a hydrogen branch, and a working fluid pipeline;

[0007] The temperature-controlled vaporizer is filled with a heat-exchanging medium, and is divided into a lower liquid phase working medium area and an upper gas phase working medium area according to the state of the heat-exchanging medium; the seawater pipeline is sequentially connected to the seawater stop valve, the seawater pump, the first channel of the hydrogen temperature riser and the temperature-controlled vaporizer, and flows out of the temperature-controlled vaporizer after heat exchange with the liquid phase working medium area of ​​the temperature-controlled vaporizer; the liquid hydrogen pipeline flows out of the temperature-controlled vaporizer after heat exchange with the gas phase working medium area of ​​the temperature-controlled vaporizer and is connected to the temperature sensor, and then is divided into two branches; the first branch is connected to the constant temperature hydrogen stop valve for discharging constant temperature hydrogen; the second branch is sequentially connected to the high temperature hydrogen stop valve, the second branch is sequentially connected to the high temperature hydrogen stop valve, and ... The gas stop valve and the second channel of the hydrogen temperature riser are used to discharge high-temperature hydrogen; the liquid hydrogen pipeline located upstream of the temperature-controlled vaporizer is also provided with a hydrogen branch, which is sequentially connected to the liquid hydrogen stop valve and the second channel of the cooler and merges with the liquid hydrogen pipeline; a working fluid pipeline inlet and a working fluid pipeline outlet are provided at the gas phase working fluid area of ​​the temperature-controlled vaporizer, and the working fluid pipeline outlet flows back to the working fluid pipeline outlet through the working fluid pipeline and forms a circulation passage, and the working fluid pipeline is sequentially connected with a pressure reducing valve, the first channel of the cooler, a working fluid inlet valve, a working fluid storage tank, a working fluid outlet valve, a working fluid pump, an electric heater, and a booster valve;

[0008] The first channel and the second channel of the hydrogen temperature raiser form a heat exchange contact, and the first channel and the second channel of the cooler form a heat exchange contact.

[0009] Preferably, the hydrogen heater and cooler are both gas-liquid heat exchangers.

[0010] Preferably, the seawater pipeline and the liquid hydrogen pipeline inside the temperature-controlled vaporizer are both coil structures.

[0011] Preferably, the evaporation temperature and condensation temperature of the heat exchange medium inside the temperature-controlled evaporator are both between the seawater temperature and the liquid hydrogen temperature.

[0012] Preferably, the exterior of the liquid hydrogen pipeline and the hydrogen branch is coated with polyurethane foam material or a double-layer vacuum tube.

[0013] In a second aspect, the present invention provides a control method for the indirect heat exchange liquid hydrogen vaporization system according to any one of the first aspects, which is as follows:

[0014] All valves are closed, and the seawater pump and working fluid pump are stopped;

[0015] S1: Open the seawater stop valve and start the seawater pump. Under the action of the seawater pump, the external seawater enters the seawater pipeline and passes through the seawater stop valve, the seawater pump, and the first channel of the hydrogen heater in sequence before entering the temperature-controlled vaporizer. The liquid working medium in the liquid phase working medium area is heated by its own heat, and the seawater after heat release and cooling is discharged from the temperature-controlled vaporizer through the seawater pipeline.

[0016] S2: The liquid working fluid in the liquid working fluid zone inside the temperature-controlled vaporizer absorbs heat and vaporizes, then rises to the gaseous working fluid zone and heats the liquid hydrogen pipeline. The gaseous working fluid releases heat and condenses into liquid, and returns to the liquid working fluid zone under the action of gravity;

[0017] S3: When constant temperature hydrogen is needed, the constant temperature hydrogen stop valve is opened; the vaporized liquid hydrogen exchanges heat with the gas phase working medium area inside the temperature controlled vaporizer through the liquid hydrogen pipeline, absorbs the heat of the gaseous working medium, completes vaporization and reaches the set temperature, and then enters the subsequent hydrogen-using equipment through the constant temperature hydrogen stop valve;

[0018] When high-temperature hydrogen is needed, the high-temperature hydrogen stop valve is opened; the vaporized liquid hydrogen exchanges heat with the gas phase working medium area inside the temperature-controlled vaporizer through the liquid hydrogen pipeline, absorbs the heat of the gaseous working medium and completes vaporization, then enters the second channel of the hydrogen heater through the high-temperature hydrogen stop valve to exchange heat with the seawater pipeline, further absorbs the heat of the seawater to increase the temperature, and finally enters the subsequent hydrogen-using equipment;

[0019] S4: During the operation of the temperature-controlled vaporizer, the temperature of vaporized hydrogen in the liquid hydrogen pipeline can be indirectly controlled by adjusting its internal pressure, as follows:

[0020] When the reading of the temperature sensor is higher than the set hydrogen temperature, the liquid hydrogen stop valve, the pressure reducing valve and the working fluid inlet valve are opened; part of the liquid hydrogen in the liquid hydrogen pipeline enters the hydrogen branch, enters the second channel of the cooler through the liquid hydrogen stop valve to release the cold, and then returns to the liquid hydrogen pipeline again; at the same time, part of the gaseous working fluid in the gas phase working fluid zone of the temperature-controlled vaporizer enters the first channel of the cooler through the pressure reducing valve to absorb the cold and liquefy, and then enters the working fluid storage tank through the working fluid inlet valve for storage; when the internal pressure of the temperature-controlled vaporizer decreases, the heat input to the liquid hydrogen pipeline decreases, and the temperature of the vaporized hydrogen in the liquid hydrogen pipeline decreases; when the reading of the temperature sensor reaches the set value, the liquid hydrogen stop valve, the pressure reducing valve and the working fluid inlet valve are closed;

[0021] When the temperature sensor reading is lower than the set hydrogen temperature, open the working fluid outlet valve and the boost valve, start the working fluid pump and the electric heater; the liquid working fluid from the working fluid storage tank is vaporized by the electric heater and enters the gas phase working fluid area of ​​the temperature-controlled vaporizer, which increases the internal pressure of the temperature-controlled vaporizer, increases the heat input into the liquid hydrogen pipeline, and increases the temperature of the vaporized hydrogen in the liquid hydrogen pipeline; when the temperature sensor reading reaches the set value, close the working fluid outlet valve, the boost valve, the working fluid pump and the electric heater.

[0022] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects: using seawater as the heat exchange medium for vaporizing liquid hydrogen has the advantages of high heat exchange efficiency, stable process, small size of vaporizing device, and suitability for marine transportation; using working fluid for indirect heat exchange has the advantages of high heat exchange efficiency and stable performance, and effectively avoids unfavorable heat transfer conditions such as seawater freezing; by adjusting the pressure inside the temperature-controlled vaporizer, the condensation temperature of the gaseous working fluid is regulated, so that the hydrogen generated by the vaporization of liquid hydrogen can be discharged at a specific temperature; the vaporized hydrogen can be heated again by seawater, and the temperature can be close to the seawater temperature, thereby increasing the selectivity of subsequent hydrogen equipment for hydrogen at different temperatures.

[0023] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of an indirect heat exchange liquid hydrogen vaporization system;

[0025] In the figure: seawater pipeline 1, seawater stop valve 2, seawater pump 3, hydrogen temperature riser 4, temperature control vaporizer 5, liquid hydrogen pipeline 6, temperature sensor 7, constant temperature hydrogen stop valve 8, high temperature hydrogen stop valve 9, hydrogen branch 10, liquid hydrogen stop valve 11, cooler 12, working fluid pipeline 13, pressure reducing valve 14, working fluid inlet valve 15, working fluid storage tank 16, working fluid outlet valve 17, working fluid pump 18, electric heater 19, booster valve 20, liquid phase working fluid area 21, gas phase working fluid area 22. DETAILED DESCRIPTION

[0026] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0027] In the description of the present invention, it is to be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0028] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for the purpose of distinguishing descriptions, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0029] In the description of the present invention, it is necessary to understand that the expression "high temperature" in "high temperature hydrogen shut-off valve 9" is only used to distinguish the description purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the temperature limit of the indicated technical features.

[0030] like Figure 1 As shown, an indirect heat exchange liquid hydrogen vaporization system provided by the present invention mainly includes a seawater pipeline 1, a seawater stop valve 2, a seawater pump 3, a hydrogen temperature riser 4, a temperature control vaporizer 5, a liquid hydrogen pipeline 6, a temperature sensor 7, a constant temperature hydrogen stop valve 8, a high temperature hydrogen stop valve 9, a hydrogen branch 10, a liquid hydrogen stop valve 11, a cooler 12, a working fluid pipeline 13, a pressure reducing valve 14, a working fluid inlet valve 15, a working fluid storage tank 16, a working fluid outlet valve 17, a working fluid pump 18, an electric heater 19, a booster valve 20, a liquid phase working fluid zone 21, and a gas phase working fluid zone 22.

[0031] The hydrogen temperature increaser 4 and the cooler 12 have a first channel and a second channel inside thereof, respectively, which can form heat exchange contact.

[0032] The connection method of each component of the present invention will be described in detail below.

[0033] In the present invention, the temperature-controlled vaporizer 5 is filled with heat exchange medium, and is divided into two parts according to the state of the heat exchange medium, namely, a lower liquid phase medium area 21 and an upper gas phase medium area 22. In actual use, the medium in the liquid phase medium area 21 absorbs the heat of the seawater pipeline 1 and vaporizes, and then rises to the gas phase medium area 22; the medium in the gas phase medium area 22 absorbs the cold of the liquid hydrogen pipeline 6 and liquefies, and returns to the liquid phase medium area 21 under the action of gravity, and the cycle repeats.

[0034] In the present invention, the seawater pipeline 1 is sequentially connected to the seawater stop valve 2, the seawater pump 3, the first channel of the hydrogen temperature riser 4 and the temperature-controlled vaporizer 5, and flows out of the temperature-controlled vaporizer 5 after heat exchange with the liquid working medium area 21 of the temperature-controlled vaporizer 5. The seawater pipeline 1 can use external seawater to heat the hydrogen in the second channel of the hydrogen temperature riser 4 and the liquid working medium area 21 inside the temperature-controlled vaporizer 5.

[0035] As a preferred embodiment of the present invention, the hydrogen temperature increaser 4 is a gas-liquid heat exchanger. In order to achieve a better heat exchange effect, part of the seawater pipeline 1 located inside the temperature-controlled vaporizer 5 is a high-efficiency heat exchange structure such as a coil.

[0036] In the present invention, the liquid hydrogen pipeline 6 flows out of the temperature-controlled vaporizer 5 after heat exchange with the gas phase working medium area 22 of the temperature-controlled vaporizer 5 and is connected to the temperature sensor 7, and then is divided into two branches. The first branch is connected to the constant temperature hydrogen stop valve 8, which is used to discharge the constant temperature hydrogen. The second branch is connected in sequence to the high-temperature hydrogen stop valve 9 and the second channel of the hydrogen warmer 4, which is used to discharge the high-temperature hydrogen (the "high temperature hydrogen" here is the "high temperature" compared to the temperature of the "constant temperature hydrogen", and does not refer to a specific temperature value). In other words, the front end of the liquid hydrogen pipeline 6 is connected in sequence to the gas phase working medium area 22 of the temperature-controlled vaporizer 5 and the temperature sensor 7, and the rear end is divided into two branches: the first branch is connected to the constant temperature hydrogen stop valve 8, and the constant temperature air from the temperature-controlled vaporizer 5 is directly discharged; the second branch is connected in sequence to the high-temperature hydrogen stop valve 9 and the second channel of the hydrogen warmer 4, and the constant temperature hydrogen is heat-exchanged with seawater again to further increase its outlet temperature.

[0037] In the present invention, the liquid hydrogen pipeline 6 located upstream of the temperature-controlled vaporizer 5 is further provided with a hydrogen branch 10, which sequentially connects the liquid hydrogen stop valve 11 and the second channel of the cooler 12 and merges with the liquid hydrogen pipeline 6. In other words, the front end of the liquid hydrogen pipeline 6 is further connected with a hydrogen branch 10, which sequentially connects the liquid hydrogen stop valve 11 and the second channel of the cooler 12, and uses part of the liquid hydrogen in the liquid hydrogen pipeline 6 to cool the gaseous working medium and return it to the liquid hydrogen pipeline 6 again.

[0038] As a preferred embodiment of the present invention, the cooler 12 is a gas-liquid heat exchanger. In order to achieve a better heat exchange effect, part of the liquid hydrogen pipeline 6 located inside the temperature-controlled vaporizer 5 is a high-efficiency heat exchange structure such as a coil. The exterior of the liquid hydrogen pipeline 6 and the hydrogen branch 10 should be coated with polyurethane foam material or a double-layer vacuum tube.

[0039] In the present invention, a working fluid pipeline inlet and a working fluid pipeline outlet are provided at the gas phase working fluid zone 22 of the temperature-controlled vaporizer 5. The working fluid pipeline outlet flows back to the working fluid pipeline outlet through the working fluid pipeline 13 and forms a circulation passage. The working fluid pipeline 13 is sequentially connected with a pressure reducing valve 14, a first channel of a cooler 12, a working fluid inlet valve 15, a working fluid storage tank 16, a working fluid outlet valve 17, a working fluid pump 18, an electric heater 19, and a boost valve 20, and the pressure regulation inside the temperature-controlled vaporizer 5 can be achieved through different operating processes.

[0040] As a preferred embodiment of the present invention, the working fluid storage tank 16 is a highly insulated low-temperature storage tank.

[0041] The present invention further provides a control method using the above-mentioned indirect heat exchange liquid hydrogen vaporization system. The control method is specifically as follows:

[0042] Based on the above structure and assuming that all valves are in a closed state, the seawater pump 3, the working fluid pump 18 and other equipment are in a stopped state.

[0043] S1: Open the seawater stop valve 2 and start the seawater pump 3. Under the action of the seawater pump 3, the external seawater enters the seawater pipeline 1, and passes through the seawater stop valve 2, the seawater pump 3, and the first channel of the hydrogen temperature riser 4 in sequence, and then enters the temperature control vaporizer 5, and uses its own heat to heat the liquid working medium in the liquid phase working medium area 21, and the seawater after heat release and temperature reduction is discharged from the temperature control vaporizer 5 through the seawater pipeline 1.

[0044] S2: The liquid working medium in the liquid working medium zone 21 inside the temperature-controlled vaporizer 5 absorbs heat and vaporizes, then rises to the gaseous working medium zone 22 and heats the liquid hydrogen pipeline 6. The gaseous working medium releases heat and condenses into liquid, and returns to the liquid working medium zone 21 under the action of gravity.

[0045] S3: According to the different requirements of subsequent equipment for different hydrogen temperatures, it can be divided into two situations:

[0046] S31: When constant temperature hydrogen is needed, the constant temperature hydrogen stop valve 8 is opened. The vaporized liquid hydrogen exchanges heat with the gas phase working medium area 22 inside the temperature control vaporizer 5 through the liquid hydrogen pipeline 6, absorbs the heat of the gaseous working medium, completes vaporization and reaches the set temperature, and then enters the subsequent hydrogen-using equipment through the constant temperature hydrogen stop valve 8.

[0047] S32: When high-temperature hydrogen is needed, open the high-temperature hydrogen stop valve 9. The vaporized liquid hydrogen exchanges heat with the gas phase working medium area 22 inside the temperature-controlled vaporizer 5 through the liquid hydrogen pipeline 6, absorbs the heat of the gaseous working medium and completes vaporization, then enters the second channel of the hydrogen heater 4 through the high-temperature hydrogen stop valve 9 to exchange heat with the seawater pipeline 1, further absorbs the heat of the seawater to increase the temperature, and finally enters the subsequent hydrogen-using equipment.

[0048] S4: Operating principle of the temperature-controlled vaporizer 5: The temperature of the gaseous working medium when condensing is directly related to the internal pressure of the temperature-controlled vaporizer 5. Therefore, by adjusting the internal pressure of the temperature-controlled vaporizer 5, the temperature of the vaporized hydrogen can be indirectly controlled and the icing problem can be avoided. The specific operating method includes the following two parts:

[0049] S41: When the reading of the temperature sensor 7 is higher than the set hydrogen temperature, it is necessary to reduce the condensation temperature of the gaseous working medium, that is, to reduce the internal pressure of the temperature-controlled vaporizer 5. At this time, the liquid hydrogen stop valve 11, the pressure reducing valve 14 and the working medium inlet valve 15 can be opened. Part of the liquid hydrogen in the liquid hydrogen pipeline 6 enters the hydrogen branch 10, enters the second channel of the cooler 12 through the liquid hydrogen stop valve 11 to release the cold, and then returns to the liquid hydrogen pipeline 6 again. At the same time, part of the gaseous working medium in the gas phase working medium area 22 of the temperature-controlled vaporizer 5 enters the first channel of the cooler 12 through the pressure reducing valve 14 to absorb the cold and liquefy, and then enters the working medium storage tank 16 through the working medium inlet valve 15 for storage. When the internal pressure of the temperature-controlled vaporizer 5 is reduced, the heat input to the liquid hydrogen pipeline 6 is reduced, and the temperature of the vaporized hydrogen in the liquid hydrogen pipeline 6 is reduced. When the reading of the temperature sensor 7 reaches the set value, the liquid hydrogen stop valve 11, the pressure reducing valve 14 and the working medium inlet valve 15 are closed.

[0050] S42: When the reading of the temperature sensor 7 is lower than the set hydrogen temperature, it is necessary to increase the condensation temperature of the gaseous working medium, that is, to increase the internal pressure of the temperature-controlled vaporizer 5. At this time, the working medium outlet valve 17 and the boost valve 20 can be opened, and the working medium pump 18 and the electric heater 19 can be started. The liquid working medium from the working medium storage tank 16 is vaporized by the electric heater 19 and enters the gas phase working medium area 22 of the temperature-controlled vaporizer 5, so that the internal pressure of the temperature-controlled vaporizer 5 increases, the heat input to the liquid hydrogen pipeline 6 increases, and the temperature of the vaporized hydrogen in the liquid hydrogen pipeline 6 increases. When the reading of the temperature sensor 7 reaches the set value, the working medium outlet valve 17, the boost valve 20, the working medium pump 18 and the electric heater 19 are closed.

[0051] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. An indirect heat exchange liquid hydrogen vaporization system, characterized in that: It comprises a temperature-controlled vaporizer (5), a seawater pipeline (1), a liquid hydrogen pipeline (6), a hydrogen branch (10) and a working fluid pipeline (13); The temperature-controlled vaporizer (5) is filled with a heat exchange medium and is divided into a lower liquid phase working medium area (21) and an upper gas phase working medium area (22) according to the state of the heat exchange medium. The seawater pipeline (1) is sequentially connected to the seawater stop valve (2), the seawater pump (3), the first channel of the hydrogen temperature riser (4) and the temperature-controlled vaporizer (5). The seawater pipeline (1) exchanges heat with the liquid phase working medium area (21) of the temperature-controlled vaporizer (5) and then flows out of the temperature-controlled vaporizer (5). The liquid hydrogen pipeline (6) exchanges heat with the gas phase working medium area (22) of the temperature-controlled vaporizer (5) and then flows out of the temperature-controlled vaporizer (5) and is connected to the temperature sensor (7), and then is divided into two branches. The first branch is connected to the constant temperature hydrogen stop valve (8) for discharging constant temperature hydrogen. The second branch is sequentially connected to the high temperature hydrogen stop valve (9) and The second channel of the hydrogen temperature booster (4) is used to discharge high-temperature hydrogen; the liquid hydrogen pipeline (6) located upstream of the temperature-controlled vaporizer (5) is further provided with a hydrogen branch (10), the hydrogen branch (10) is sequentially connected to the liquid hydrogen stop valve (11) and the second channel of the cooler (12) and merges with the liquid hydrogen pipeline (6); a working fluid pipeline inlet and a working fluid pipeline outlet are provided at the gas phase working fluid region (22) of the temperature-controlled vaporizer (5), the working fluid pipeline outlet flows back to the working fluid pipeline outlet through the working fluid pipeline (13) and forms a circulation path, and the working fluid pipeline (13) is sequentially connected to the pressure reducing valve (14), the first channel of the cooler (12), the working fluid inlet valve (15), the working fluid storage tank (16), the working fluid outlet valve (17), the working fluid pump (18), the electric heater (19), and the boost valve (20); The first channel and the second channel of the hydrogen temperature raiser (4) form a heat exchange contact, and the first channel and the second channel of the cooler (12) form a heat exchange contact.

2. The indirect heat exchange liquid hydrogen vaporization system according to claim 1, characterized in that: The hydrogen temperature increaser (4) and the cooler (12) are both gas-liquid heat exchangers.

3. The indirect heat exchange liquid hydrogen vaporization system according to claim 1, characterized in that: The seawater pipeline (1) and the liquid hydrogen pipeline (6) located inside the temperature-controlled vaporizer (5) are both coil structures.

4. The indirect heat exchange liquid hydrogen vaporization system according to claim 1, characterized in that: The evaporation temperature and condensation temperature of the heat exchange medium inside the temperature-controlled evaporator (5) are both between the seawater temperature and the liquid hydrogen temperature.

5. The indirect heat exchange liquid hydrogen vaporization system according to claim 1, characterized in that: The exterior of the liquid hydrogen pipeline (6) and the hydrogen branch line (10) is coated with polyurethane foam material or a double-layer vacuum tube.

6. A control method using the indirect heat exchange liquid hydrogen vaporization system according to any one of claims 1 to 5, characterized in that: The details are as follows: All valves are in a closed state, and the seawater pump (3) and the working fluid pump (18) are in a stopped state; S1: Open the seawater stop valve (2) and start the seawater pump (3); under the action of the seawater pump (3), external seawater enters the seawater pipeline (1), passes through the seawater stop valve (2), the seawater pump (3), and the first channel of the hydrogen heater (4) in sequence, and then enters the temperature-controlled vaporizer (5), where the liquid working medium in the liquid phase working medium area (21) is heated by its own heat, and the seawater after heat release and temperature reduction is discharged from the temperature-controlled vaporizer (5) through the seawater pipeline (1); S2: The liquid working medium in the liquid working medium region (21) inside the temperature-controlled vaporizer (5) absorbs heat and vaporizes, then rises to the gaseous working medium region (22) and heats the liquid hydrogen pipeline (6); the gaseous working medium releases heat and condenses into liquid, and returns to the liquid working medium region (21) under the action of gravity; S3: When constant temperature hydrogen is required, the constant temperature hydrogen stop valve (8) is opened; the vaporized liquid hydrogen exchanges heat with the gas phase working medium area (22) inside the temperature control vaporizer (5) through the liquid hydrogen pipeline (6), absorbs the heat of the gaseous working medium, completes vaporization and reaches the set temperature, and then enters the subsequent hydrogen-using equipment through the constant temperature hydrogen stop valve (8); When high-temperature hydrogen is needed, the high-temperature hydrogen stop valve (9) is opened; the vaporized liquid hydrogen exchanges heat with the gas phase working medium area (22) inside the temperature-controlled vaporizer (5) through the liquid hydrogen pipeline (6), absorbs the heat of the gaseous working medium and completes vaporization, then passes through the high-temperature hydrogen stop valve (9) into the second channel of the hydrogen heater (4), exchanges heat with the seawater pipeline (1), further absorbs the heat of the seawater to increase the temperature, and finally enters the subsequent hydrogen-using equipment; S4: During the operation of the temperature-controlled vaporizer (5), the temperature of vaporized hydrogen in the liquid hydrogen pipeline (6) can be indirectly controlled by adjusting the internal pressure thereof, as follows: When the reading of the temperature sensor (7) is higher than the set hydrogen temperature, the liquid hydrogen stop valve (11), the pressure reducing valve (14) and the working fluid inlet valve (15) are opened; part of the liquid hydrogen in the liquid hydrogen pipeline (6) enters the hydrogen branch (10), passes through the liquid hydrogen stop valve (11) and enters the second channel of the cooler (12) to release cold energy, and then returns to the liquid hydrogen pipeline (6) again; at the same time, part of the gaseous working fluid in the gas phase working fluid zone (22) in the temperature control vaporizer (5) enters the first channel of the cooler (12) through the pressure reducing valve (14) to absorb cold energy and liquefy, and then passes through the working fluid inlet valve (15) and enters the working fluid storage tank (16) for storage; when the internal pressure of the temperature control vaporizer (5) decreases, the heat input to the liquid hydrogen pipeline (6) decreases, and the temperature of the vaporized hydrogen in the liquid hydrogen pipeline (6) decreases; when the reading of the temperature sensor (7) reaches the set value, the liquid hydrogen stop valve (11), the pressure reducing valve (14) and the working fluid inlet valve (15) are closed; When the reading of the temperature sensor (7) is lower than the set hydrogen temperature, the working fluid outlet valve (17) and the boost valve (20) are opened, and the working fluid pump (18) and the electric heater (19) are started; the liquid working fluid from the working fluid storage tank (16) is vaporized by the electric heater (19) and enters the gas phase working fluid area (22) of the temperature control vaporizer (5), so that the internal pressure of the temperature control vaporizer (5) increases, the heat input to the liquid hydrogen pipeline (6) increases, and the temperature of the vaporized hydrogen in the liquid hydrogen pipeline (6) increases; when the reading of the temperature sensor (7) reaches the set value, the working fluid outlet valve (17), the boost valve (20), the working fluid pump (18) and the electric heater (19) are closed.

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