Liquid hydrogen refueling system

Abstract

This invention provides a liquid hydrogen refueling system, including a liquid hydrogen storage tank with a first liquid outlet and a return gas outlet; a plunger pump with an inlet, a second liquid outlet, and a return port; the inlet of the plunger pump is connected to the first liquid outlet of the liquid hydrogen storage tank via a first pipeline, and the return port of the plunger pump is connected to the return gas outlet of the liquid hydrogen storage tank via a second pipeline; the second liquid outlet of the plunger pump is used to communicate with liquid hydrogen application equipment; a third pipeline is connected to the second pipeline and is disposed on the surface of the first pipeline to recover hydrogen from the return port of the plunger pump and the liquid hydrogen storage tank to precool the first pipeline; by recovering hydrogen from the return port of the plunger pump and using flash vapor from the liquid hydrogen storage tank as a precooling medium through the third pipeline to precool the first pipeline, it is beneficial to utilize the cooling capacity of hydrogen in a timely manner, which can significantly reduce the discharge of liquid hydrogen for precooling, reduce liquid hydrogen loss, and shorten the precooling time.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen refueling equipment technology, and mainly to a liquid hydrogen refueling system. Background Technology

[0002] Before starting, the cryogenic plunger pump for liquid hydrogen needs to be pre-cooled. However, the pumps in the hydrogen refueling station need to be stopped and started dozens of times a day depending on the refueling load. Each time, new liquid hydrogen is introduced to complete the pre-cooling process, which results in a lot of waste. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a liquid hydrogen refueling system that can effectively reduce the pre-cooling time before the plunger pump is started and improve the utilization rate of hydrogen energy.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] One technical solution of this application proposes a liquid hydrogen refueling system, comprising:

[0006] The liquid hydrogen storage tank is equipped with a first liquid outlet and a gas return outlet;

[0007] A plunger pump is provided with an inlet, a second outlet, and a reflux port. The inlet of the plunger pump is connected to the first outlet of the liquid hydrogen storage tank through a first pipeline. The reflux port of the plunger pump is connected to the gas return port of the liquid hydrogen storage tank through a second pipeline. The second outlet of the plunger pump is used to connect to liquid hydrogen application equipment.

[0008] A third pipeline, connected to the second pipeline, is disposed on the surface of the first pipeline to pre-cool the first pipeline by recovering hydrogen from the return port of the plunger pump and the liquid hydrogen storage tank.

[0009] According to one technical solution of this application, the liquid hydrogen refueling system further includes a first outer tube, the first pipeline is installed in the cavity of the first outer tube, a sandwich is formed between the first pipeline and the first outer tube, and the third pipeline is at least partially located in the sandwich.

[0010] According to one technical solution of this application, the liquid hydrogen refueling system further includes a second outer tube, the second pipeline being installed in the cavity of the second outer tube, and a sandwich is formed between the second pipeline and the second outer tube.

[0011] According to one technical solution of this application, the interlayer is a vacuum interlayer.

[0012] According to one technical solution of this application, a first switching valve is provided on the second pipeline. The first switching valve is connected to the second pipeline between the return gas port of the liquid hydrogen storage tank and the connection node between the third pipeline and the second pipeline, so as to communicate with the return gas port of the liquid hydrogen storage tank along the second pipeline.

[0013] According to one technical solution of this application, a second switching valve is provided on the second pipeline. The second switching valve is connected to the second pipeline between the return port of the plunger pump and the connection node between the third pipeline and the second pipeline, so as to communicate with the return port of the plunger pump along the second pipeline.

[0014] According to one technical solution of this application, the liquid hydrogen refueling system further includes a vent valve, which is installed on the second pipeline. When the pipeline pressure of the second pipeline exceeds a threshold, the vent valve opens to release the hydrogen gas in the second pipeline.

[0015] According to one technical solution of this application, the vent valve is connected to the second pipeline between the second switching valve and the return port of the plunger pump.

[0016] According to one technical solution of this application, the liquid hydrogen refueling system further includes a temperature measuring device, which is provided at the reflux port of the plunger pump and is used to measure the temperature at the reflux port of the plunger pump.

[0017] According to one technical solution of this application, the first pipeline is further provided with a third switching valve, which is used to control the opening and closing of the first pipeline.

[0018] Beneficial effects:

[0019] This application proposes a liquid hydrogen refueling system. The first outlet of the liquid hydrogen storage tank is connected to the inlet of a plunger pump, and the return port of the plunger pump is connected to the return gas port of the liquid hydrogen storage tank, forming a medium circulation flow between the liquid hydrogen storage tank and the plunger pump, achieving liquid hydrogen reflux. The second outlet of the plunger pump is used to connect to liquid hydrogen application equipment, thereby transporting hydrogen from the liquid hydrogen storage tank to the liquid hydrogen application equipment, realizing liquid hydrogen refueling. By connecting a third pipeline to the second pipeline and placing the third pipeline on the surface of the first pipeline, the third pipeline recovers hydrogen from the return port of the plunger pump and uses flash vapor from the liquid hydrogen storage tank as a precooling medium to precool the first pipeline. This facilitates timely utilization of cooling capacity, reduces production energy consumption, and can maintain the low temperature state of the first pipeline for a longer period. Before the plunger pump is restarted next time, the discharge of liquid hydrogen used for precooling can be significantly reduced, minimizing liquid hydrogen loss and reducing precooling time. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a liquid hydrogen refueling system according to an embodiment of this application;

[0021] The correspondence between the reference numerals and the component names is as follows:

[0022] 1. Liquid hydrogen storage tank, 101. First liquid outlet, 102. Gas return port;

[0023] 2-plunger pump, 201 inlet, 202 second outlet, 203 reflux port;

[0024] 31 First pipeline, 32 First outer pipeline;

[0025] 41 Second pipe, 42 Second outer pipe;

[0026] 51 Third pipeline;

[0027] 6. First switching valve;

[0028] 7. Second switching valve;

[0029] 8. Vent valve;

[0030] 9. Temperature measuring device;

[0031] 10. Third switching valve. Detailed Implementation

[0032] This invention provides a liquid hydrogen refueling system. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the scope of protection of the invention.

[0033] In the description of this invention, it should be understood that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In a liquid hydrogen refueling system, the cryogenic plunger pump 2 primarily functions to transport liquid hydrogen from the storage tank to downstream equipment or systems. Specifically, the cryogenic plunger pump 2 utilizes the reciprocating motion of a plunger within the pump chamber to draw liquid hydrogen from the storage tank and discharge it, thus achieving liquid hydrogen transport. Before starting the cryogenic plunger pump 2, pre-cooling is required to ensure the liquid hydrogen temperature within the pump chamber reaches a suitable level. The pump 2 can only be started after the temperature at the return port 102 is checked and deemed acceptable. After the cryogenic plunger pump 2 stops operating, the liquid hydrogen remaining in the inlet pipe will heat up and vaporize. Before the next startup, new liquid hydrogen needs to be introduced into the pipe to complete the re-pre-cooling process.

[0036] Currently, the pumps in hydrogen refueling stations need to be stopped and started dozens of times a day depending on the refueling load. Each time, new liquid hydrogen is introduced to complete the recooling process, which results in a lot of waste.

[0037] Based on this, embodiments of this application propose a liquid hydrogen refueling system, including a liquid hydrogen storage tank 1, a plunger pump 2, a first pipeline 31, a second pipeline 41, and a third pipeline 51.

[0038] Please refer to the appendix. Figure 1 The liquid hydrogen storage tank 1 is provided with a first liquid outlet 101 and a return gas outlet 102; the plunger pump 2 is provided with a liquid inlet 201, a second liquid outlet 202 and a return port 203. The liquid inlet 201 of the plunger pump 2 is connected to the first liquid outlet 101 of the liquid hydrogen storage tank 1 through a first pipeline 31, and the return port 203 of the plunger pump 2 is connected to the return gas outlet 102 of the liquid hydrogen storage tank 1 through a second pipeline 41. The second liquid outlet 202 of the plunger pump 2 is used to connect with liquid hydrogen application equipment.

[0039] By connecting the first outlet 101 of the liquid hydrogen storage tank 1 to the inlet 201 of the plunger pump 2, and connecting the return port 203 of the plunger pump 2 to the return gas port 102 of the liquid hydrogen storage tank 1, the second outlet 202 of the plunger pump 2 is used to connect to the liquid hydrogen application equipment, thereby transporting the hydrogen in the liquid hydrogen storage tank 1 to the liquid hydrogen application equipment, realizing the filling and return of liquid hydrogen. In this way, the liquid hydrogen filling system can fill liquid hydrogen more efficiently, while avoiding the waste and leakage of liquid hydrogen, and improving the safety and reliability of the system.

[0040] The third pipeline 51 is connected to the second pipeline 41 and is disposed on the surface of the first pipeline 31 to recover the hydrogen from the return port 203 of the plunger pump 2 and the liquid hydrogen storage tank 1 to pre-cool the first pipeline 31.

[0041] In the liquid hydrogen refueling system, the first pipeline 31 connects the liquid hydrogen storage tank 1 and the plunger pump 2, serving as the inlet channel for the plunger pump 2. During the flow of liquid hydrogen from the storage tank 1 through the first pipeline 31 to the plunger pump 2, heat is generated due to the flow and friction, causing the temperature of the first pipeline 31 to rise. This temperature rise may lead to vaporization of the liquid hydrogen within the first pipeline 31, thus affecting the refueling efficiency and system stability.

[0042] Therefore, the third pipeline 51 is connected to the second pipeline 41. Since the second pipeline 41 connects the return port 203 of the plunger pump 2 and the return gas port 102 of the liquid hydrogen storage tank 1, the second pipeline 41 can transport the hydrogen at the return port of the plunger pump 2 to the gas phase layer in the liquid hydrogen storage tank 1. In this way, the hydrogen at the return port 203 of the plunger pump 2 and the flash vapor evaporated above the liquid hydrogen storage tank 1 can be recovered and utilized through the setting of the third pipeline 51, thereby precooling the first pipeline 31.

[0043] Specifically, liquid hydrogen flows from liquid hydrogen storage tank 1 to plunger pump 2 through first pipeline 31. Most of the liquid hydrogen is delivered to the hydrogen-using equipment by the plunger pump, while the remaining hydrogen is returned to liquid hydrogen storage tank 1 through plunger pump 2's return port 203 under the action of plunger pump 2. In this way, the setting of third pipeline 51 can effectively recover the hydrogen at plunger pump 2's return port 203 as a cold source to pre-cool the first pipeline 31.

[0044] On the other hand, as liquid hydrogen is stored in the tank, its pressure gradually decreases with increasing temperature. As the pressure decreases, the boiling point of liquid hydrogen also decreases, causing the initially liquid hydrogen to evaporate and form a flash vapor layer above the liquid hydrogen storage tank 1. Driven by the pressure difference, the flash vapor above the liquid hydrogen storage tank 1 enters the third pipe 51. Since the third pipe 51 is located on the surface of the first pipe 31, it can effectively pre-cool the first pipe 31. In this way, not only can the hydrogen retained in the second pipe 41 and the low-temperature flash vapor in the liquid hydrogen storage tank 1 be used as a cold source to cool the first pipe 31, improving the utilization efficiency of hydrogen cooling capacity and reducing the pre-cooling time of the first pipe 31, but also reducing the amount of hydrogen evaporated in the liquid hydrogen storage tank 1, thereby avoiding threats to the storage and safety of the liquid hydrogen storage tank 1.

[0045] Understandably, by designing the connection between the third pipeline 51 and the second pipeline 41, the hydrogen from the return port 203 of the plunger pump 2 and the flash vapor above the liquid hydrogen storage tank 1 can be cleverly utilized as a cold source. This facilitates the timely utilization of cooling capacity, reduces production energy consumption, and can maintain the low temperature state of the plunger pump 2 inlet pipeline, i.e., the first pipeline 31, for a longer period of time. In this way, pre-cooling may not be necessary before the plunger pump 2 is started again, and the discharge of liquid hydrogen for pre-cooling can be greatly reduced, minimizing liquid hydrogen loss.

[0046] More specifically, the input end of the third pipeline 51 is connected to the second pipeline 41, and the output end of the third pipeline 51 is connected to the hydrogen-using equipment. In this way, the first pipeline 31 is pre-cooled and its cooling capacity is fully utilized. Then, it is directly delivered to the hydrogen-using equipment at the end, reducing liquid hydrogen loss and fully realizing the utilization of hydrogen.

[0047] In some embodiments, a first outer tube 32 is further included, and a first conduit 31 is installed within the cavity of the first outer tube 32, forming a sandwich between the first conduit 31 and the first outer tube 32. The third conduit 51 is at least partially located within the sandwich. By installing the first conduit 31 within the cavity of the first outer tube 32, the first conduit 31 and the third conduit 51 are less susceptible to interference and damage from the external environment under the protection of the first outer tube 32, thereby improving the stability and reliability of the system.

[0048] Furthermore, a sandwich structure is formed between the first pipe 31 and the first outer pipe 32. The sandwich effectively isolates the first pipe 31 and the third pipe 51 installed in the sandwich from the external environment, playing a good heat preservation role. This not only reduces the heat loss of liquid hydrogen during transportation and storage, but also improves the pre-cooling effect of the third pipe 51 on the first pipe 31, thereby improving the storage efficiency and stability of liquid hydrogen.

[0049] Preferably, the third pipe 51 located in the interlayer is spirally wound around the outer surface of the first pipe 31, which increases the area of ​​the third pipe surrounding the second pipe, thereby effectively improving the precooling effect.

[0050] To give a more detailed example, the third pipe 51, which is wound around the outer surface of the first pipe 31, uses a heat exchange coil, which has a better pre-cooling effect.

[0051] In some embodiments, the liquid hydrogen refueling system further includes a second outer pipe 42, with a second conduit 41 installed within the cavity of the second outer pipe 42, forming a sandwich between the second conduit 41 and the second outer pipe 42. This sandwich structure effectively isolates the second conduit 41 from heat exchange with the external environment, thereby reducing heat loss from the second conduit 41 between the plunger pump 2 return port 203 and the liquid hydrogen storage tank 1, thus providing good insulation.

[0052] More specifically, a vacuum jacket is formed between the first pipe 31 and the first outer pipe 32, and a vacuum jacket is also formed between the second pipe 41 and the second outer pipe 42. The vacuum jacket has excellent thermal insulation properties, effectively preventing heat transfer between the pipes within the vacuum jacket and the outside environment, reducing energy consumption, and providing efficient heat preservation. In a liquid hydrogen refueling system, the vacuum jacket reduces heat exchange between liquid hydrogen and the external environment, improving the storage efficiency and stability of liquid hydrogen. Furthermore, the vacuum jacket design also reduces the evaporation and leakage of liquid hydrogen, minimizing environmental impact.

[0053] In some embodiments, a first switching valve 6 is provided on the second pipeline 41. The first switching valve 6 is connected to the second pipeline 41 between the return port 102 of the liquid hydrogen storage tank 1 and the connection node between the third pipeline 51 and the second pipeline 41, so as to communicate with the return port 102 of the liquid hydrogen storage tank 1 along the second pipeline 41.

[0054] Please refer to Figure 1 The third pipeline 51 is connected to the second pipeline 41 to form a connection node. By setting the first switch valve 6 between the return gas port 102 of the liquid hydrogen storage tank 1 and the connection node, the flow rate and direction of liquid hydrogen can be controlled and adjusted more conveniently, thereby controlling the source of cooling energy for the third pipeline 51.

[0055] Specifically, when the first switching valve 6 is closed, it prevents flash vapor in the liquid hydrogen storage tank 1 from entering the third pipeline 51. At this time, the medium in the third pipeline 51 originates from the return port 203 of the plunger pump 2. For example, when the flash vapor level in the liquid hydrogen storage tank 1 is low, when the temperature at the return port 203 of the plunger pump 2 reaches the acceptable temperature, or in other situations (such as a leak in the third pipeline 51) where it is not necessary to use the flash vapor in the liquid hydrogen storage tank 1 to pre-cool the first pipeline 31, this can be achieved by closing the first switching valve 6. Moreover, the flow rate of flash vapor from the liquid hydrogen storage tank 1 to the third pipeline 51 can be controlled by adjusting the opening degree of the first switching valve 6, thereby achieving precise control over the flow rate of the medium in the third pipeline 51 and the pre-cooling process of the second pipeline 41.

[0056] Furthermore, the presence of the first switching valve 6 can increase the safety of the liquid hydrogen refueling system. If the second pipeline 41 malfunctions or leaks during the liquid hydrogen refueling process, the first switching valve 6 can be quickly closed to cut off the flow of liquid hydrogen and prevent the accident from escalating.

[0057] In some embodiments, a second switching valve 7 is provided on the second pipeline 41. The second switching valve 7 is connected to the second pipeline 41 between the return port 203 of the plunger pump 2 and the connection node between the third pipeline 51 and the second pipeline 41, so as to communicate with the return port 203 of the plunger pump 2 along the second pipeline 41. The third pipeline 51 is connected to the second pipeline 41 to form a connection node. By providing the second switching valve 7 between the return port 203 of the plunger pump 2 and the connection node, the opening of the second switching valve 7 allows the hydrogen at the return port 203 of the plunger pump 2 to communicate with the second pipeline 41 along the return port 203 of the plunger pump 2, thereby flowing to the third pipeline 51. The closing of the second switching valve 7 correspondingly disconnects the communication between the return port 203 of the plunger pump 2 and the second pipeline 41. Moreover, in actual use, the opening degree of the second switching valve 7 can be adjusted according to actual needs, thereby achieving precise control of the hydrogen return flow to the third pipeline 51.

[0058] Specifically, this application includes both a first switching valve 6 and a second switching valve 7. The connection node formed by the third pipeline 51 and the second pipeline 41 is located between the first switching valve 6 and the second switching valve 7. Thus, by controlling the opening and closing of the first switching valve 6 and the second switching valve 7, the source of the medium in the third pipeline 51 can be controlled. For example, by controlling the first switching valve 6 to open and the second switching valve 7 to close, the cooling medium in the third pipeline 51 comes from the flash vapor in the liquid hydrogen storage tank 1; by controlling the first switching valve 6 to close and the second switching valve 7 to open, the cooling medium in the third pipeline 51 comes from the return port 203 of the plunger pump 2. Furthermore, by controlling the opening degree of the first switching valve 6 and the second switching valve 7, the flow rate of the cooling medium in the third pipeline 51 is controlled, thereby controlling the pre-cooling speed and effect on the first pipeline 31.

[0059] In some embodiments, the liquid hydrogen refueling system further includes a vent valve 8, which is disposed on the second pipeline 41. When the pipeline pressure of the second pipeline 41 exceeds a threshold, the vent valve 8 opens to release hydrogen gas from the second pipeline 41. By providing a vent valve 8 on the second pipeline 41, the pressure of the hydrogen gas in the second pipeline 41 can be regulated.

[0060] Specifically, when the pressure in the second pipeline 41 exceeds a threshold, the vent valve 8 can be opened to release some of the hydrogen gas in the second pipeline 41, thereby reducing the pressure in the second pipeline 41 and maintaining stable system operation. In this way, the vent valve 8 provides a safety protection function. During liquid hydrogen refueling, if the pressure in the second pipeline 41 is too high, it may damage the system or cause a safety accident. By setting up the vent valve 8, hydrogen gas can be released in a timely manner when the pressure is too high, reducing the pressure and thus protecting the safety of the liquid hydrogen refueling system and reducing safety risks to operators.

[0061] The vent valve 8 also plays a role in mitigating cavitation in the plunger pump 2. When the plunger pump 2 is running, uneven gas intake and exhaust can lead to a vacuum inside the pump, causing liquid vaporization and the formation of bubbles. These bubbles can burst under high pressure, creating shock waves that damage the components of the plunger pump 2, thus causing cavitation. By using the vent valve 8, hydrogen gas on the second pipeline 41 is released into the atmosphere, reducing the gas pressure in the second pipeline 41. This reduces the formation and bursting of bubbles, thereby mitigating the damage caused by cavitation to the plunger pump 2.

[0062] Specifically, the vent valve 8 is connected to the second pipeline 41 between the second switching valve 7 and the return port 203 of the plunger pump 2. In this way, the vent valve 8 is located on the upstream pipeline of the second switching valve 7, and the opening and closing states of the second switching valve 7 will not have a venting effect on the vent valve 8, further improving the safety and stability of the liquid hydrogen refueling system.

[0063] In some embodiments, the liquid hydrogen refueling system further includes a temperature measuring device 9. The temperature measuring device 9 is located at the return port 203 of the plunger pump 2 and is used to measure the temperature of the return port 203. By providing the temperature measuring device 9, the temperature at the return port 203 of the plunger pump 2 can be monitored in real time, thereby understanding the flow state of liquid hydrogen in the pipeline and the operating status of the plunger pump 2. Thus, by monitoring the temperature, it can be determined whether the temperature of the return port 203 of the plunger pump 2 has reached the qualified starting temperature of the plunger pump 2, and the plunger pump 2 can be started based on the temperature measured by the temperature measuring device 9, ensuring the safe operation of the liquid hydrogen refueling system.

[0064] To give a more detailed example, the temperature measuring device 9 is a temperature gauge.

[0065] In some embodiments, the first pipeline 31 is further provided with a third switching valve 10, which is used to control the opening and closing of the first pipeline 31. In this way, by operating the opening and closing of the third switching valve 10, the flow of liquid hydrogen can be cut off under certain circumstances, or the third switching valve 10 can be opened to allow liquid hydrogen to flow from the liquid hydrogen storage tank 1 to the plunger pump 2.

[0066] Moreover, operators can control the flow rate and volume of liquid hydrogen according to actual needs, meeting different refueling requirements and improving the accuracy and efficiency of the liquid hydrogen refueling process.

[0067] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A liquid hydrogen refueling system, characterized in that, include: The liquid hydrogen storage tank is equipped with a first liquid outlet and a gas return outlet; A plunger pump is provided with an inlet, a second outlet, and a reflux port. The inlet of the plunger pump is connected to the first outlet of the liquid hydrogen storage tank through a first pipeline. The reflux port of the plunger pump is connected to the gas return port of the liquid hydrogen storage tank through a second pipeline. The second outlet of the plunger pump is used to connect to liquid hydrogen application equipment. The third pipeline is connected to the second pipeline and is disposed on the surface of the first pipeline to pre-cool the first pipeline by recovering hydrogen from the return port of the plunger pump and the liquid hydrogen storage tank. The second pipeline is equipped with a first switching valve, which is connected to the second pipeline between the return port of the liquid hydrogen storage tank and the connection node of the third pipeline and the second pipeline, so as to communicate with the return port of the liquid hydrogen storage tank along the second pipeline. The second pipeline is provided with a second switching valve, which is connected to the second pipeline between the return port of the plunger pump and the connection node between the third pipeline and the second pipeline, so as to communicate with the return port of the plunger pump along the second pipeline; The liquid hydrogen refueling system also includes a first outer tube, the first pipeline being installed in the cavity of the first outer tube, a sandwich formed between the first pipeline and the first outer tube, and the third pipeline being at least partially located within the sandwich.

2. The liquid hydrogen refueling system according to claim 1, characterized in that, Also includes: The second outer tube, the second pipeline is installed in the cavity of the second outer tube, and a sandwich is formed between the second pipeline and the second outer tube.

3. The liquid hydrogen refueling system according to claim 1 or 2, characterized in that, The interlayer is a vacuum interlayer.

4. The liquid hydrogen refueling system according to claim 1, characterized in that, Also includes: A vent valve is provided on the second pipeline. When the pipeline pressure in the second pipeline exceeds a threshold, the vent valve opens to release hydrogen gas from the second pipeline.

5. The liquid hydrogen refueling system according to claim 4, characterized in that, The vent valve is connected to the second pipeline between the second switching valve and the return port of the plunger pump.

6. The liquid hydrogen refueling system according to claim 1, characterized in that, Also includes: A temperature measuring device is provided at the reflux port of the plunger pump, and the temperature measuring device is used to measure the temperature at the reflux port of the plunger pump.

7. The liquid hydrogen refueling system according to claim 1, characterized in that, The first pipeline is also equipped with a third switching valve, which is used to control the opening and closing of the first pipeline.

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