Liquid hydrogen filling system and control method

Abstract

This invention relates to a liquid hydrogen refueling system and control method. The system includes a storage tank composed of an inner tank and an outer tank. The interlayer between the inner and outer tanks is in a high vacuum state. Liquid hydrogen is contained in the inner tank. A refueling gun is connected to the bottom of the inner tank via a refueling pipeline. A first shut-off valve is provided on the refueling pipeline. A refueling pump is provided on the refueling pipeline between the first shut-off valve and the refueling gun. A transfer port is connected to the refueling pipeline between the refueling pump and the first shut-off valve via a transfer pipeline. A second shut-off valve is provided on the transfer pipeline. A return gas gun and a balance port are correspondingly connected to the top of the inner tank via a return gas pipeline and a pressure balance pipeline. A third shut-off valve is provided on the return gas pipeline, and a fourth shut-off valve is provided on the pressure balance pipeline. The system has the advantages of simple structure, strong versatility, good safety, and high reliability. The method has the advantages of simple process, convenient operation, and safety and reliability.

Description

Technical Field

[0001] This invention relates to a liquid hydrogen refueling technology, specifically to a liquid hydrogen refueling system with transfer and refueling functions, and a control method for the system. Background Technology

[0002] Compared to gaseous hydrogen, liquid hydrogen has advantages such as lower transportation costs, higher energy density, and smaller footprint. Hydrogen refueling stations, as refueling points for hydrogen-powered vehicles, are the central link in the utilization and development of hydrogen energy. Due to the relatively late start of the hydrogen energy industry, my country's current hydrogen refueling stations are mainly high-pressure gaseous hydrogen stations. However, with the rapid development of the hydrogen energy industry, liquid hydrogen will become the main direction for large-scale hydrogen energy utilization in the future, and the market demand for liquid hydrogen refueling stations will gradually increase. Currently, liquid hydrogen refueling technology in this field is not yet mature, especially lacking liquid hydrogen refueling technology that can simultaneously adapt to the needs of multiple scenarios, including transfer and refueling. Summary of the Invention

[0003] The purpose of this invention is to provide a liquid hydrogen refueling system and control method. The system has the advantages of simple structure, strong versatility, good safety and high reliability; the method has the advantages of simple process, convenient operation and safety and reliability.

[0004] To address the aforementioned problems in the prior art, this invention provides a liquid hydrogen refueling system, comprising a storage tank composed of an inner tank and an outer tank. The interlayer between the inner and outer tanks is in a high vacuum state. Liquid hydrogen is contained in the inner tank. A refueling gun is connected to the bottom of the inner tank via a refueling pipeline extending from the outer tank. A first shut-off valve is provided on the refueling pipeline. A refueling pump is provided on the refueling pipeline between the first shut-off valve and the refueling gun. A transfer port is connected to the refueling pipeline between the refueling pump and the first shut-off valve via a transfer pipeline. A second shut-off valve is provided on the transfer pipeline. A return gas gun and a balance port are correspondingly connected to the top of the inner tank via a return gas pipeline extending from the outer tank and a pressure balance pipeline. A third shut-off valve is provided on the return gas pipeline, and a fourth shut-off valve is provided on the pressure balance pipeline.

[0005] Furthermore, the present invention provides a liquid hydrogen refueling system, wherein a first check valve is provided on the refueling pipeline between the refueling pump and the refueling gun, a fifth shut-off valve is provided on the refueling pipeline between the first check valve and the refueling gun, a sixth shut-off valve is provided on the return gas pipeline between the third shut-off valve and the return gas gun, the return gas pipeline between the sixth shut-off valve and the third shut-off valve is connected to the refueling pipeline between the first check valve and the fifth shut-off valve through a bypass pipeline, and a seventh shut-off valve is provided on the bypass pipeline.

[0006] Furthermore, in a liquid hydrogen refueling system of the present invention, the refueling pipeline between the fifth shut-off valve and the bypass pipeline is connected to the return gas pipeline between the sixth shut-off valve and the return gas gun via a pressure regulating pipeline, and a pressure regulating valve is provided on the pressure regulating pipeline.

[0007] Furthermore, in a liquid hydrogen refueling system of the present invention, the pressure regulating pipeline between the pressure regulating valve and the return gas pipeline is connected to a return gas seat through a residual liquid recovery pipeline, and a second one-way valve is provided on the residual liquid recovery pipeline.

[0008] Furthermore, the present invention provides a liquid hydrogen refueling system, wherein a liquid hydrogen flow meter is provided on the refueling pipeline between the fifth shut-off valve and the pressure regulating pipeline, and a hydrogen flow meter is provided on the return gas pipeline between the return gas gun and the sixth shut-off valve.

[0009] Furthermore, the present invention provides a liquid hydrogen refueling system, wherein the first, second, third, and fourth shut-off valves are manual shut-off valves, and the fifth, sixth, and seventh shut-off valves are pneumatic shut-off valves.

[0010] Based on the same concept, the present invention also provides a control method for the above-mentioned liquid hydrogen refueling system, comprising the following steps:

[0011] S1. In the initial state, the first shut-off valve, the second shut-off valve, the third shut-off valve, the fourth shut-off valve, the fifth shut-off valve, the sixth shut-off valve, and the seventh shut-off valve are closed.

[0012] S2. After connecting the filling gun and return gas gun to the filling port and return gas port of the vehicle-mounted liquid hydrogen cylinder, open the first shut-off valve, the third shut-off valve, the fifth shut-off valve and the sixth shut-off valve, and start the filling pump.

[0013] S3. After the liquid hydrogen in the vehicle liquid hydrogen cylinder is filled to the required level, stop the filling pump, close the first shut-off valve, and remove the return gas gun from the vehicle liquid hydrogen cylinder and return it to its original position.

[0014] S4. Remove the refueling gun from the vehicle-mounted liquid hydrogen cylinder and insert it into the return gas seat. After the residual liquid hydrogen in the refueling line has vaporized, close the third, fifth, and sixth shut-off valves, and remove the refueling gun from the return gas seat and return it to its original position.

[0015] Optionally, the control method for a liquid hydrogen refueling system of the present invention further includes the following steps:

[0016] S5-1. After connecting the transfer port and balance port to the liquid hydrogen transfer vehicle's liquid filling port and return gas port, open the first shut-off valve, the second shut-off valve, and the fourth shut-off valve, and open the liquid hydrogen transfer vehicle's booster vaporizer.

[0017] S6-1. After the liquid hydrogen in the storage tank is added to meet the requirements, shut off the booster vaporizer of the liquid hydrogen transfer vehicle, and disconnect the transfer port and balance port from the liquid hydrogen transfer vehicle after closing the first stop valve, the second stop valve and the fourth stop valve.

[0018] Optionally, the control method for a liquid hydrogen refueling system of the present invention further includes the following steps:

[0019] S5-2. After connecting the transfer port and balance port to the liquid hydrogen transfer vehicle's liquid filling port and return gas port, open the second, fourth, third, and seventh shut-off valves and start the filling pump.

[0020] S6-2. After the liquid hydrogen in the storage tank is added to meet the requirements, stop the filling pump, and disconnect the transfer port and balance port from the liquid hydrogen transfer vehicle after closing the second, fourth, third and seventh shut-off valves.

[0021] Furthermore, the present invention provides a control method for a liquid hydrogen refueling system, wherein the filling port of the vehicle-mounted liquid hydrogen cylinder is an interface for adding liquid hydrogen into the vehicle-mounted liquid hydrogen cylinder, and the venting port of the vehicle-mounted liquid hydrogen cylinder is an interface for discharging hydrogen gas from the vehicle-mounted liquid hydrogen cylinder; the filling port of the liquid hydrogen transfer vehicle is an interface for discharging liquid hydrogen from the liquid hydrogen transfer vehicle, and the venting port of the liquid hydrogen transfer vehicle is an interface for introducing hydrogen gas into the liquid hydrogen transfer vehicle.

[0022] Compared with existing technologies, the liquid hydrogen refueling system and control method of this invention have the following advantages: This invention uses a storage tank composed of an inner tank and an outer tank, wherein the interlayer between the inner and outer tanks is in a high-vacuum state. Liquid hydrogen is contained in the inner tank. The bottom of the inner tank is connected to a refueling gun via a refueling pipeline extending from the outer tank. A first shut-off valve is installed on the refueling pipeline. A refueling pump is installed on the refueling pipeline between the first shut-off valve and the refueling gun. The refueling pipeline between the refueling pump and the first shut-off valve is connected to a transfer port via a transfer pipeline. A second shut-off valve is installed on the transfer pipeline. The top of the inner tank is connected to a return gas gun and a balance port via a return gas pipeline extending from the outer tank and a pressure balance pipeline, respectively. A third shut-off valve is installed on the return gas pipeline, and a fourth shut-off valve is installed on the pressure balance pipeline. This constitutes a liquid hydrogen refueling system that is simple in structure, highly versatile, safe, and reliable. This invention utilizes a storage tank composed of an inner and outer tank, maintaining a high vacuum in the space between them to prevent heat exchange between the liquid hydrogen in the inner tank and the external environment, thus ensuring safety and reliability. The system also features a filling pipeline for refilling onboard liquid hydrogen cylinders, with a return gas pipeline ensuring filling efficiency and stability. Furthermore, the system includes a transfer pipeline for transferring liquid hydrogen from a liquid hydrogen transfer vehicle to the storage tank, with a pressure balancing pipeline ensuring transfer efficiency and stability. Therefore, this invention provides a liquid hydrogen filling system that simultaneously performs both filling and transfer functions, solving the problem that existing technologies cannot simultaneously adapt to multiple filling and transfer scenarios. The specific process for adding and transferring liquid hydrogen is as follows: Initially, close the first, second, third, and fourth shut-off valves; connect the filling nozzle and return nozzle to the filling port and return port of the vehicle-mounted liquid hydrogen cylinder, respectively; then open the first and third shut-off valves and start the filling pump; once the liquid hydrogen in the vehicle-mounted liquid hydrogen cylinder reaches the required level, stop the filling pump, close the first and third shut-off valves, and remove the filling nozzle and return nozzle from the vehicle-mounted liquid hydrogen cylinder. This completes the process of adding liquid hydrogen to the vehicle-mounted liquid hydrogen cylinder. The process of adding liquid hydrogen to the tank involves: After connecting the transfer port and balance port to the liquid hydrogen transfer vehicle's filling port and return port respectively, opening the first, second, and fourth shut-off valves and the liquid hydrogen transfer vehicle's booster vaporizer; once the liquid hydrogen in the storage tank reaches the required level, closing the liquid hydrogen transfer vehicle's booster vaporizer, and then disconnecting the transfer port and balance port from the liquid hydrogen transfer vehicle after closing the first, second, and fourth shut-off valves. This completes the process of transferring liquid hydrogen from the liquid hydrogen transfer vehicle to the storage tank. It should be noted that the filling gun and return gas gun are existing technologies in the field, both having an on / off function; that is, they automatically open when inserted into their corresponding interfaces and automatically close when removed. The control method for the liquid hydrogen filling system provided by this invention has the advantages of simple process, convenient operation, and safety and reliability.

[0023] The following detailed description of a liquid hydrogen refueling system and control method according to the present invention, with reference to the accompanying drawings, illustrates the specific embodiments. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a liquid hydrogen refueling system according to the present invention. Detailed Implementation

[0025] First, it should be noted that the directional terms such as up, down, left, right, front, and back used in this invention are merely descriptions based on the accompanying drawings for ease of understanding, and are not intended to limit the technical solution or the scope of protection claimed in this invention.

[0026] like Figure 1 The embodiment of the liquid hydrogen refueling system of the present invention shown includes a storage tank 1 composed of an inner tank 11 and an outer tank 12, wherein the interlayer between the inner tank 11 and the outer tank 12 is in a high vacuum state, and liquid hydrogen is contained in the inner tank 11. The bottom of the inner tank 11 is connected to a refueling gun 21 via a refueling pipeline 2 extending from the outer tank 12. A first shut-off valve 22 is installed on the refueling pipeline 2. A refueling pump 23 is installed on the refueling pipeline 2 between the first shut-off valve 22 and the refueling gun 21. The refueling pipeline 2 between the refueling pump 23 and the first shut-off valve 22 is connected to a transfer port 31 via a transfer pipeline 3, and a second shut-off valve 32 is installed on the transfer pipeline 3. The top of the inner tank 11 is connected to a return gas gun 41 and a balance port 51 respectively via a return gas pipeline 4 and a pressure balance pipeline 5 extending from the outer tank 12. A third shut-off valve 42 is installed on the return gas pipeline 4, and a fourth shut-off valve 52 is installed on the pressure balance pipeline 5.

[0027] The above configuration constitutes a liquid hydrogen refueling system that is simple in structure, highly versatile, safe, and reliable. This invention uses a storage tank 1 composed of an inner tank 11 and an outer tank 12, with the interlayer between the inner and outer tanks maintained in a high-vacuum state. This reduces heat exchange between the liquid hydrogen in the inner tank 11 and the external environment, ensuring safety and reliability. The refueling pipeline 2 enables the system to refuel onboard liquid hydrogen cylinders, and the return gas pipeline 4 ensures refueling efficiency and stability. The transfer pipeline 3 enables the system to transfer liquid hydrogen from a liquid hydrogen transfer vehicle to the storage tank 1, and the pressure balancing pipeline 4 ensures transfer efficiency and stability. As can be seen from the above analysis, the liquid hydrogen refueling system provided by this invention simultaneously possesses refueling and transfer functions, solving the problem that existing technologies cannot simultaneously adapt to the needs of multiple refueling and transfer scenarios. The specific process of filling and transferring is as follows: In the initial state, the first shut-off valve 22, the second shut-off valve 32, the third shut-off valve 42, and the fourth shut-off valve 52 are closed; after connecting the filling gun 21 and the return gas gun 41 to the filling port and return gas port of the vehicle-mounted liquid hydrogen cylinder, the first shut-off valve 22 and the third shut-off valve 42 are opened and the filling pump 23 is started. The liquid hydrogen in the inner tank 11 will enter the vehicle-mounted liquid hydrogen cylinder through the filling pipeline 2, and the hydrogen in the vehicle-mounted liquid hydrogen cylinder will enter the inner tank 11 through the return gas pipeline 4; when the liquid hydrogen in the vehicle-mounted liquid hydrogen cylinder is filled to the required level, the filling pump 23 is stopped, the first shut-off valve 22 and the third shut-off valve 42 are closed, and the filling gun 21 and the return gas gun 41 are pulled out of the vehicle-mounted liquid hydrogen cylinder and returned to their original positions. This completes the process of filling the vehicle-mounted liquid hydrogen cylinder with liquid hydrogen. After connecting the transfer port 31 and the balance port 51 to the liquid hydrogen transfer vehicle's filling port and return port, open the first shut-off valve 22, the second shut-off valve 32, the fourth shut-off valve 52, and the liquid hydrogen transfer vehicle's booster vaporizer. The liquid hydrogen in the liquid hydrogen transfer vehicle will enter the inner tank 11 through the transfer pipeline 3 and the filling pipeline 2, and the hydrogen in the inner tank 11 will enter the liquid hydrogen transfer vehicle through the pressure balance pipeline 5. When the liquid hydrogen in the storage tank 1 is filled to the required level, close the booster vaporizer of the liquid hydrogen transfer vehicle, and disconnect the transfer port 31 and the balance port 51 from the liquid hydrogen transfer vehicle after closing the first shut-off valve 22, the second shut-off valve 32, and the fourth shut-off valve 52. This completes the process of transferring liquid hydrogen into the storage tank 1 using the liquid hydrogen transfer vehicle. It should be noted that the filling gun 21 and the return air gun 41 are existing technologies in the field, and their structure and connection method are well known to those skilled in the art. Both have a switching function, that is, they automatically turn on when inserted into the corresponding interface and automatically turn off when pulled out of the corresponding interface.It should also be noted that vehicle-mounted liquid hydrogen cylinders and liquid hydrogen transfer vehicles are existing technologies in this field, and their structures and connection methods are well known to those skilled in the art. The filling port of the vehicle-mounted liquid hydrogen cylinder refers to the interface for adding liquid hydrogen into the cylinder, while the venting port refers to the interface for venting hydrogen gas from the cylinder. During the process of adding liquid hydrogen to the vehicle-mounted liquid hydrogen cylinder, the venting port is connected to the inner tank 11 through the venting pipe 4, thus achieving pressure balance between the inner tank 11 and the vehicle-mounted liquid hydrogen cylinder, effectively preventing pressure loss due to liquid hydrogen accumulation. Excessive pressure inside the hydrogen cylinder affects refueling efficiency and safety. The filling port of the liquid hydrogen transfer vehicle is the interface for discharging liquid hydrogen from the vehicle, while the return port is the interface for introducing hydrogen into the vehicle. During the process of transferring liquid hydrogen from the liquid hydrogen transfer vehicle to the storage tank 1, the return port of the liquid hydrogen transfer vehicle is connected to the inner tank 11 through the pressure balance pipeline 5, thus achieving pressure balance between the inner tank 11 and the liquid hydrogen transfer vehicle. This effectively prevents excessive pressure in the inner tank 11 from affecting refueling efficiency and safety.

[0028] As an optimization, this specific embodiment installs a first check valve 24 on the filling pipeline 2 between the filling pump 23 and the filling gun 21. This prevents liquid hydrogen from flowing back into the storage tank 1 from the on-board liquid hydrogen cylinder and the filling pipeline 2 during the filling process, thus improving safety and reliability. Simultaneously, this specific embodiment installs a fifth shut-off valve 25 on the filling pipeline 2 between the first check valve 24 and the filling gun 21, and a sixth shut-off valve 43 on the return gas pipeline 4 between the third shut-off valve 42 and the return gas gun 41. The return gas pipeline 4 between the sixth shut-off valve 43 and the third shut-off valve 42 is connected to the filling pipeline 2 between the first check valve 24 and the fifth shut-off valve 25 via a bypass pipeline 6, and a seventh shut-off valve 61 is installed on the bypass pipeline 6. This setup improves system safety and ease of maintenance through the fifth shut-off valve 25 and the sixth shut-off valve 43, and enhances system functionality and practicality through the bypass line 6 and the seventh shut-off valve 61. For liquid hydrogen transfer vehicles without self-pressurization capabilities, i.e., those without a pressurized vaporizer, the bypass line 6 can be used to transfer liquid hydrogen to storage tank 1. The specific process is as follows: In the initial state, the fifth shut-off valve 25, the sixth shut-off valve 43, and the seventh shut-off valve 61 are closed; when transferring liquid hydrogen to storage tank 1, after aligning the transfer port 31 and the balance port 51 with the liquid filling port and return gas port of the liquid hydrogen transfer vehicle, the second shut-off valve is opened. 32. The third shut-off valve 42, the fourth shut-off valve 52, and the seventh shut-off valve 61 are connected, and the filling pump 23 is started. The liquid hydrogen in the liquid hydrogen transfer vehicle will enter the inner tank 11 in sequence through the transfer pipeline 3, the filling pipeline 2, the bypass pipeline 6, and the return gas pipeline 4. The hydrogen in the inner tank 11 will enter the liquid hydrogen transfer vehicle through the pressure balance pipeline 5. When the liquid hydrogen in the storage tank 1 is filled to the required level, the filling pump 23 is stopped, and after closing the second shut-off valve 32, the third shut-off valve 42, the fourth shut-off valve 52, and the seventh shut-off valve 61, the connection between the transfer port 31 and the balance port 51 and the liquid hydrogen transfer vehicle is disconnected. This completes the process of transferring liquid hydrogen to the storage tank 1 through the bypass pipeline 6. It should be noted that after adding the fifth shut-off valve 25 and the sixth shut-off valve 43, when adding liquid hydrogen to the vehicle-mounted liquid hydrogen cylinder, the fifth shut-off valve 25 and the sixth shut-off valve 43 should be opened after the first shut-off valve 22 and the third shut-off valve 42 are opened, and the fifth shut-off valve 25 and the sixth shut-off valve 43 should be closed after the filling is completed.

[0029] As an optimization, this specific embodiment connects the filling pipeline 2 between the fifth shut-off valve 25 and the bypass pipeline 6 to the return gas pipeline 4 between the sixth shut-off valve 43 and the return gas gun 41 via the pressure regulating pipeline 7, and installs a pressure regulating valve 71 on the pressure regulating pipeline 7. This configuration ensures that during the process of filling the vehicle-mounted liquid hydrogen cylinder with liquid hydrogen via the filling pipeline 2 and the return gas pipeline 4, when the pressure in the filling pipeline 2 becomes too high, the pressure regulating valve 71 will automatically open. The hydrogen in the filling pipeline 2 will then sequentially pass through the pressure regulating pipeline 7 and the return gas pipeline 4 into the inner tank 11, instead of entering the vehicle-mounted liquid hydrogen cylinder via the filling pipeline 2 and the filling gun 21, thus achieving pressure regulation and improving safety and stability. As an optimization, this specific embodiment also connects the pressure regulating pipeline 7 between the pressure regulating valve 71 and the return gas pipeline 4 to the return gas seat 81 via the residual liquid recovery pipeline 8, and installs a second one-way valve 82 on the residual liquid recovery pipeline 8. This system allows for the recovery of residual liquid hydrogen in the filling line 2 via the residual liquid recovery line 8 when filling the vehicle-mounted liquid hydrogen cylinder with liquid hydrogen through the filling line 2 and the return line 4. This improves economy, practicality, and safety. The specific process is as follows: After connecting the filling nozzle 21 and the return line 41 to the filling port and return port of the vehicle-mounted liquid hydrogen cylinder, open the first shut-off valve 22, the third shut-off valve 42, the fifth shut-off valve 25, and the sixth shut-off valve 43, and start the filling pump 23; when the liquid hydrogen in the vehicle-mounted liquid hydrogen cylinder... After the required level is reached, first stop the filling pump 23, close the first shut-off valve 22, and remove the return gas gun 41 from the vehicle-mounted liquid hydrogen cylinder and return it to its original position. Then, remove the filling gun 21 from the vehicle-mounted liquid hydrogen cylinder and insert it into the return gas seat 81. After the residual liquid hydrogen in the filling pipeline 2 is vaporized and flows sequentially through the residual liquid recovery pipeline 8, the pressure regulating pipeline 7, and the return gas pipeline 4 into the inner tank 11, close the third shut-off valve 42, the fifth shut-off valve 25, and the sixth shut-off valve 43, and remove the filling gun 21 from the return gas seat 81 and return it to its original position. This structure and control method not only realizes the vaporization and recovery of the liquid hydrogen remaining in the filling pipeline 2, but also effectively prevents pipeline pressure buildup, improving safety and reliability.

[0030] In practical applications, to facilitate intuitive monitoring of liquid hydrogen and hydrogen flow rates, this invention includes a liquid hydrogen flow meter 26 on the filling pipeline 2 between the fifth shut-off valve 25 and the pressure regulating pipeline 7, and a hydrogen flow meter 44 on the return pipeline 4 between the return gas gun 41 and the sixth shut-off valve 43. To improve ease of operation and safety, this invention employs manual shut-off valves for the first shut-off valve 22, second shut-off valve 32, third shut-off valve 42, and fourth shut-off valve 52 for on-site control, while using pneumatic shut-off valves for the fifth shut-off valve 25, sixth shut-off valve 43, and seventh shut-off valve 61 for remote control.

[0031] Based on the same concept, the present invention also provides a control method for the liquid hydrogen refueling system, specifically including the following steps:

[0032] S1. In the initial state, the first shut-off valve 22, the second shut-off valve 32, the third shut-off valve 42, the fourth shut-off valve 52, the fifth shut-off valve 25, the sixth shut-off valve 43, and the seventh shut-off valve 61 are closed.

[0033] S2. After connecting the filling gun 21 and the return gas gun 41 to the filling port and return gas port of the vehicle-mounted liquid hydrogen cylinder, open the first shut-off valve 22, the third shut-off valve 42, the fifth shut-off valve 25 and the sixth shut-off valve 43, and start the filling pump 23.

[0034] S3. After the liquid hydrogen in the vehicle liquid hydrogen cylinder is filled to the required level, stop the filling pump 23, close the first shut-off valve 22, and remove the return gas gun 41 from the vehicle liquid hydrogen cylinder and return it to its original position.

[0035] S4. Remove the refueling nozzle 21 from the vehicle-mounted liquid hydrogen cylinder and insert it into the return gas seat 81. After the residual liquid hydrogen in the refueling line 2 has vaporized, close the third shut-off valve 42, the fifth shut-off valve 25, and the sixth shut-off valve 43, and remove the refueling nozzle 21 from the return gas seat 81. After this step, the liquid hydrogen remaining in the refueling line 2 will vaporize and enter the storage tank 1 sequentially through the residual liquid recovery line 8, the pressure regulating line 7, and the return gas line 4, thus achieving both vaporization and recovery of residual liquid hydrogen and preventing pressure buildup in the pipeline.

[0036] This completes the process of refilling the vehicle-mounted liquid hydrogen tank with liquid hydrogen in a single operation.

[0037] For liquid hydrogen transfer vehicles equipped with self-pressurization capabilities, i.e., liquid hydrogen transfer vehicles equipped with pressurized vaporizers, the present invention uses steps S5-1 and S6-1 to transfer liquid hydrogen into storage tank 1:

[0038] S5-1. After connecting the transfer port 31 and the balance port 51 to the liquid hydrogen transfer vehicle's liquid filling port and return gas port, open the first shut-off valve 22, the second shut-off valve 32 and the fourth shut-off valve 52, and open the liquid hydrogen transfer vehicle's booster vaporizer.

[0039] S6-1. Once the liquid hydrogen in storage tank 1 has reached the required level, shut off the booster vaporizer of the liquid hydrogen transfer vehicle. After closing the first shut-off valve 22, the second shut-off valve 32, and the fourth shut-off valve 52, disconnect the transfer port 31 and the balance port 51 from the liquid hydrogen transfer vehicle. This completes the process of transferring liquid hydrogen to storage tank 1 using the booster vaporizer of the liquid hydrogen transfer vehicle.

[0040] For liquid hydrogen transfer vehicles that do not have self-pressurization capabilities, i.e., liquid hydrogen transfer vehicles without a pressurized vaporizer, the present invention uses steps S5-2 and S6-2 to transfer liquid hydrogen to storage tank 1:

[0041] S5-2. After connecting the transfer port 31 and balance port 51 to the liquid hydrogen transfer vehicle's liquid filling port and return gas port, open the second shut-off valve 32, the fourth shut-off valve 52, the third shut-off valve 42 and the seventh shut-off valve 61, and start the filling pump 23.

[0042] S6-2. Once the liquid hydrogen in storage tank 1 has reached the required level, stop the filling pump 23, and disconnect the transfer port 31 and balance port 51 from the liquid hydrogen transfer vehicle after closing the second stop valve 32, the fourth stop valve 52, the third stop valve 42, and the seventh stop valve 61. This completes the process of transferring liquid hydrogen to storage tank 1 using the filling pump 23.

[0043] The control method for the liquid hydrogen refueling system provided by this invention has the advantages of simple process, convenient operation, and safety and reliability.

[0044] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Various modifications made by those skilled in the art based on the technical solutions of the present invention without departing from the design concept of the present invention should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A liquid hydrogen refueling system, characterized in that, The storage tank (1) consists of an inner tank (11) and an outer tank (12). The interlayer between the inner tank (11) and the outer tank (12) is in a high vacuum state. Liquid hydrogen is contained in the inner tank (11). The bottom of the inner tank (11) is connected to a filling gun (21) through a filling pipe (2) extending out of the outer tank (12). A first shut-off valve (22) is provided on the filling pipe (2). A filling pump (23) is provided on the filling pipe (2) between the first shut-off valve (22) and the filling gun (21). (23) The filling pipeline (2) between the first shut-off valve (22) and the filling pipeline (3) is connected to the filling port (31) through the filling pipeline (3). The filling pipeline (3) is equipped with a second shut-off valve (32). The top of the inner tank (11) is connected to the return gas gun (41) and the balance port (51) through the return gas pipeline (4) extending out of the outer tank (12) and the pressure balance pipeline (5). The return gas pipeline (4) is equipped with a third shut-off valve (42), and the pressure balance pipeline (5) is equipped with a fourth shut-off valve (52). A first check valve (24) is provided on the filling pipeline (2) between the filling pump (23) and the filling gun (21). A fifth shut-off valve (25) is provided on the filling pipeline (2) between the first check valve (24) and the filling gun (21). A sixth shut-off valve (43) is provided on the return pipeline (4) between the third shut-off valve (42) and the return air gun (41). The return pipeline (4) between the sixth shut-off valve (43) and the third shut-off valve (42) is connected to the filling pipeline between the first check valve (24) and the fifth shut-off valve (25) via a bypass pipeline (6). The pipeline (2) is connected, and a seventh shut-off valve (61) is provided on the bypass pipeline (6); the filling pipeline (2) between the fifth shut-off valve (25) and the bypass pipeline (6) is connected to the return gas pipeline (4) between the sixth shut-off valve (43) and the return gas gun (41) through the pressure regulating pipeline (7), and a pressure regulating valve (71) is provided on the pressure regulating pipeline (7); the pressure regulating pipeline (7) between the pressure regulating valve (71) and the return gas pipeline (4) is connected to a return gas seat (81) through the residual liquid recovery pipeline (8), and a second one-way valve (82) is provided on the residual liquid recovery pipeline (8).

2. The liquid hydrogen refueling system according to claim 1, characterized in that, A liquid hydrogen flow meter (26) is installed on the filling pipeline (2) between the fifth shut-off valve (25) and the pressure regulating pipeline (7), and a hydrogen flow meter (44) is installed on the return gas pipeline (4) between the return gas gun (41) and the sixth shut-off valve (43).

3. A liquid hydrogen refueling system according to claim 1, characterized in that, The first shut-off valve (22), the second shut-off valve (32), the third shut-off valve (42) and the fourth shut-off valve (52) are manual shut-off valves, and the fifth shut-off valve (25), the sixth shut-off valve (43) and the seventh shut-off valve (61) are pneumatic shut-off valves.

4. A control method for the liquid hydrogen refueling system according to claim 1, characterized in that, Includes the following steps: S1. In the initial state, the first shut-off valve (22), the second shut-off valve (32), the third shut-off valve (42), the fourth shut-off valve (52), the fifth shut-off valve (25), the sixth shut-off valve (43), and the seventh shut-off valve (61) are closed; S2. After connecting the filling gun (21) and return gas gun (41) to the filling port and return gas port of the vehicle liquid hydrogen cylinder respectively, open the first shut-off valve (22), the third shut-off valve (42), the fifth shut-off valve (25) and the sixth shut-off valve (43), and start the filling pump (23). S3. When the liquid hydrogen in the vehicle liquid hydrogen cylinder is filled to meet the requirements, stop the filling pump (23), close the first shut-off valve (22), and pull the return gas gun (41) out of the vehicle liquid hydrogen cylinder and put it back in place. S4. Pull the filling gun (21) out of the vehicle-mounted liquid hydrogen cylinder and insert it into the return gas seat (81). After the liquid hydrogen remaining in the filling pipeline (2) is vaporized, close the third shut-off valve (42), the fifth shut-off valve (25) and the sixth shut-off valve (43), and pull the filling gun (21) out of the return gas seat (81) and put it back in place.

5. The control method for the liquid hydrogen refueling system according to claim 4, characterized in that, It also includes the following steps: S5-1. After connecting the transfer port (31) and balance port (51) to the liquid hydrogen transfer vehicle's liquid filling port and return gas port, open the first shut-off valve (22), the second shut-off valve (32) and the fourth shut-off valve (52), and open the liquid hydrogen transfer vehicle's booster vaporizer. S6-1. When the liquid hydrogen in the storage tank (1) is added to meet the requirements, the booster vaporizer of the liquid hydrogen transfer vehicle is turned off, and after the first shut-off valve (22), the second shut-off valve (32) and the fourth shut-off valve (52) are closed, the transfer port (31) and the balance port (51) are disconnected from the liquid hydrogen transfer vehicle.

6. The control method for the liquid hydrogen refueling system according to claim 4, characterized in that, It also includes the following steps: S5-2. After connecting the transfer port (31) and balance port (51) to the liquid hydrogen transfer vehicle's liquid filling port and return gas port, open the second shut-off valve (32), the fourth shut-off valve (52), the third shut-off valve (42) and the seventh shut-off valve (61), and start the filling pump (23). S6-2. When the liquid hydrogen in the storage tank (1) is added to meet the requirements, stop the filling pump (23), and disconnect the transfer port (31) and balance port (51) from the liquid hydrogen transfer vehicle after closing the second stop valve (32), the fourth stop valve (52), the third stop valve (42) and the seventh stop valve (61).

7. The control method for the liquid hydrogen refueling system according to claim 5, characterized in that, The filling port of the vehicle-mounted liquid hydrogen cylinder refers to the interface for adding liquid hydrogen to the vehicle-mounted liquid hydrogen cylinder, and the venting port of the vehicle-mounted liquid hydrogen cylinder refers to the interface for venting hydrogen from the vehicle-mounted liquid hydrogen cylinder; the filling port of the liquid hydrogen transfer vehicle refers to the interface for venting liquid hydrogen from the liquid hydrogen transfer vehicle, and the venting port of the liquid hydrogen transfer vehicle refers to the interface for introducing hydrogen into the liquid hydrogen transfer vehicle.

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