Liquid hydrogen bottle testing device and testing method thereof

Abstract

The invention relates to the technical field of liquid hydrogen bottle performance testing, in particular to a liquid hydrogen bottle testing device and a testing method thereof.The liquid hydrogen bottle testing device comprises a pressurizing pipeline, a liquid hydrogen pipeline, a liquid hydrogen testing bottle, a discharging pipeline, a vacuumizing pipeline, a vacuumizing stop valve, a vacuum pump, a heat insulation layer, a temperature sensor, an exhaust pipe, a gas collector, a safety valve and a protection cabin. According to the method, the mode that pressurization is conducted firstly and then liquid hydrogen is gradually injected is provided, and the high liquid hydrogen consumption and dangerousness of a traditional mode that the liquid hydrogen is filled firstly and then pressurization is conducted can be effectively reduced; a liquid hydrogen receiving tank driven by pressure and gravity is arranged at the bottom of the liquid hydrogen test bottle to receive a liquid hydrogen medium after the structure is invalid, so that the influence of the liquid hydrogen medium on the whole test device is effectively prevented; a temperature sensor is arranged on the heat insulation layer to indirectly warn the strength of the liquid hydrogen test bottle in an early warning mode, multiple sets of exhaust pipes are arranged to prevent the phenomenon of overpressure explosion caused by vaporization of liquid hydrogen in the heat insulation layer when the structure fails, and meanwhile the vacuum pump and the vacuumizing pipeline are combined, so that the heat protection capacity of the heat insulation layer can be effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen cylinder performance testing technology, and in particular to a liquid hydrogen cylinder testing device and testing method. Background Technology

[0002] Liquid hydrogen, with its high energy density and zero carbon emissions, has become an ideal clean energy source for aerospace and transportation. As a key device for storing liquid hydrogen, liquid hydrogen cylinders need to operate long-term in extreme environments, including ultra-low temperatures of -253°C and internal pressures (typically operating at 4-10 bar, with higher design verification pressures). Unlike traditional compressed hydrogen cylinders, liquid hydrogen cylinders not only withstand high pressures but also face drastic temperature changes and potential thermal stress challenges, placing extreme demands on the mechanical properties, sealing performance, and durability of liquid hydrogen cylinder materials.

[0003] Strength testing is the most important means of verifying the structural integrity of composite liquid hydrogen cylinders. On one hand, it ensures safety during use: strength tests (such as burst tests) directly verify the cylinder's ultimate load-bearing capacity under pressures far exceeding its operating pressure, ensuring it meets the "leak before bursting" safety design principle. This is crucial for preventing catastrophic failures and protecting personal and property safety. On the other hand, it verifies performance and optimizes design: through cyclic testing (such as tens of thousands of pressure alternation tests according to standard requirements) and ultimate burst tests, defects in materials, structural design, or manufacturing processes can be exposed, providing key data support for optimized design and ensuring product reliability throughout its entire lifecycle.

[0004] Therefore, strength testing of liquid hydrogen cylinders is a crucial link between advanced design and safe application. However, existing strength testing methods for liquid hydrogen cylinders have limitations such as high risk and large quantities of liquid hydrogen used, posing a serious challenge to the entire process of testing liquid hydrogen cylinders. Summary of the Invention

[0005] The purpose of this invention is to provide a liquid hydrogen cylinder testing device and method. By pressurizing before filling, the danger of liquid hydrogen strength testing is reduced. At the same time, a temperature sensor is set in the insulation layer of the liquid hydrogen test cylinder to indirectly test the strength of the storage tank, and an exhaust pipe is used to prevent overpressure from occurring inside the insulation layer. In addition, a pressure-driven liquid hydrogen receiving tank is set to receive the liquid hydrogen medium after structural failure, which greatly reduces the testing danger.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A liquid hydrogen cylinder testing device includes a pressurization pipeline, a liquid hydrogen pipeline, a liquid hydrogen test cylinder, a discharge pipeline, a vacuum pipeline, a vacuum shut-off valve, a vacuum pump, an insulation layer, a temperature sensor, an exhaust pipe, a gas collector, a safety valve, and a protective chamber. The pressurization pipeline is connected to a helium cylinder group at its front end and splits into three branches at its rear end. The first branch is connected to the first helium shut-off valve and the protective chamber in sequence. The second branch is connected to the second helium shut-off valve and the liquid hydrogen supply tank in sequence. The third branch is connected to the third helium shut-off valve and the liquid hydrogen test cylinder in sequence. The pressurization pipeline provides high-pressure helium to all three components. The liquid hydrogen pipeline is connected to the liquid hydrogen supply tank and the first liquid hydrogen valve at the front end, and splits into two branches at the rear end. The first branch is connected to the liquid hydrogen test bottle, and the second branch is connected to the second liquid hydrogen valve and the liquid hydrogen receiving tank in sequence. The liquid hydrogen pipeline provides liquid hydrogen medium to the liquid hydrogen test bottle and can quickly transfer the liquid hydrogen inside to the liquid hydrogen receiving tank when the liquid hydrogen test bottle structure fails. The front end of the discharge pipeline is divided into three branches. The first branch is connected to the liquid hydrogen receiving tank and the first exhaust valve in sequence. The second branch is connected to the liquid hydrogen test bottle and the second exhaust valve in sequence. The third branch is connected to the protective chamber and the back pressure valve in sequence. Then the three branches are merged and connected to the vaporizer to heat up with the flowing medium inside the pipeline, and finally discharged at high altitude. The vacuum pipeline is connected in sequence to the protective chamber, the vacuum shut-off valve and the vacuum pump, and the vacuum pipeline can evacuate the protective chamber.

[0007] As a further description of the above technical solution: The liquid hydrogen cylinder testing device includes a pressurization pipeline, a liquid hydrogen pipeline, a liquid hydrogen test cylinder, a discharge pipeline, a vacuum pipeline, a vacuum shut-off valve, a vacuum pump, an insulation layer, a temperature sensor, an exhaust pipe, a gas collector, a safety valve, and a protective chamber. The front end of the pressurization pipeline is connected to a helium cylinder group, and the rear end is divided into three branches. The first branch is connected to the first helium shut-off valve and the protective chamber in sequence. The second branch is connected to the second helium shut-off valve and the liquid hydrogen supply tank in sequence. The third branch is connected to the third helium shut-off valve and the liquid hydrogen test cylinder in sequence. The pressurization pipeline provides high-pressure helium to the three components. The liquid hydrogen pipeline is connected to the liquid hydrogen supply tank and the first liquid hydrogen valve at the front end, and splits into two branches at the rear end. The first branch is connected to the liquid hydrogen test bottle, and the second branch is connected to the second liquid hydrogen valve and the liquid hydrogen receiving tank in sequence. The liquid hydrogen pipeline provides liquid hydrogen medium to the liquid hydrogen test bottle and can quickly transfer the liquid hydrogen inside to the liquid hydrogen receiving tank when the liquid hydrogen test bottle structure fails. The front end of the discharge pipeline is divided into three branches. The first branch is connected to the liquid hydrogen receiving tank and the first exhaust valve in sequence. The second branch is connected to the liquid hydrogen test bottle and the second exhaust valve in sequence. The third branch is connected to the protective chamber and the back pressure valve in sequence. Then the three branches are merged and connected to the vaporizer to heat up with the flowing medium inside the pipeline, and finally discharged at high altitude. The vacuum pipeline is connected in sequence to the protective chamber, the vacuum shut-off valve and the vacuum pump, and the vacuum pipeline can evacuate the protective chamber.

[0008] As a further description of the above technical solution: The liquid hydrogen test bottle is equipped with an insulation layer on the outside, and the insulation layer is equipped with a through-type exhaust pipe. Multiple exhaust pipes converge to the gas collector and are connected to the entire protective chamber through a safety valve. When the liquid hydrogen test bottle structure fails and liquid hydrogen is generated, the vaporized liquid hydrogen can enter the protective chamber through the exhaust pipe, gas collector and safety valve.

[0009] As a further description of the above technical solution: Temperature sensors are installed on both sides of the exhaust pipe and connected to the controller via signal lines. When liquid hydrogen test bottle fails and liquid hydrogen is generated, the temperature difference between the temperature sensors on both sides of the exhaust pipe will increase rapidly, enabling rapid judgment of structural failure.

[0010] As a further description of the above technical solution: Multiple exhaust pipes are installed from top to bottom along the axial direction of the liquid hydrogen test bottle, and the liquid level inside the liquid hydrogen test bottle can be determined based on the value of the temperature sensor.

[0011] As a further description of the above technical solution: The liquid hydrogen pipeline and its valves must be insulated.

[0012] As a further description of the above technical solution: The vacuum pump is arranged in a multi-stage series configuration to improve the vacuum level inside the protective chamber.

[0013] As a further description of the above technical solution: A method for testing liquid hydrogen cylinders, comprising the following steps: S100, Vacuuming stage: Open the evacuation shut-off valve and start the vacuum pump. Under the action of the vacuum pump, the inside of the protective chamber reaches a vacuum state, which allows the insulation layer to be equipped with multiple exhaust pipes to still maintain a high-performance insulation state. Then close the evacuation shut-off valve and the vacuum pump. S200, Strength Testing Phase: The second helium shut-off valve, the first liquid hydrogen valve, and the second vent valve are opened. High-pressure helium from the helium cylinder group first enters the liquid hydrogen supply tank. Driven by pressure, the liquid hydrogen inside the liquid hydrogen supply tank enters the liquid hydrogen test bottle through the first liquid hydrogen valve. The hydrogen generated during the filling process is discharged at high altitude through the second vent valve and the vaporizer. The liquid level inside the liquid hydrogen test bottle is monitored using a temperature sensor. When the liquid level reaches 1 / 3 of the height, the first liquid hydrogen valve and the second vent valve are closed. The third helium shut-off valve is opened to raise the internal pressure of the liquid hydrogen test bottle to the pressure required for the strength test, and a strength test is conducted. Since the liquid hydrogen inside the test bottle is relatively small at this time, the impact of structural failure is also relatively small. Subsequently, the third helium shut-off valve is closed. The system involves opening the first liquid hydrogen valve and the second vent valve, then adding liquid hydrogen to the test bottle again. When the liquid level reaches 2 / 3 of the height, the first liquid hydrogen valve and the second vent valve are closed, and the third helium shut-off valve is opened to raise the internal pressure of the liquid hydrogen test bottle to the pressure required for the strength test, conducting a second strength test. Finally, the third helium shut-off valve is closed, the first liquid hydrogen valve and the second vent valve are opened, and liquid hydrogen is added to the test bottle again. When the liquid level reaches 3 / 3 of the height, the first liquid hydrogen valve and the second vent valve are closed, and the third helium shut-off valve is opened to raise the internal pressure of the liquid hydrogen test bottle to the pressure required for the strength test, conducting a third strength test. By gradually increasing the liquid level, the strength test of the liquid hydrogen test bottle is completed, and the test results are more comprehensive. S300, Structural Failure Handling Stage: When the liquid hydrogen test bottle experiences structural failure, firstly, close the second and third helium shut-off valves, the first liquid hydrogen valve, and the second exhaust valve. The liquid hydrogen flowing out due to the structural failure first enters the insulation layer. Due to the high temperature of the protective chamber, the liquid hydrogen will rapidly vaporize and enter the gas collector through the exhaust pipe. When the pressure inside the gas collector exceeds the set pressure of the safety valve, hydrogen gas rapidly enters the protective chamber. Simultaneously, the first helium shut-off valve is opened, and high-pressure helium gas enters the protective chamber, mixing with the vaporized hydrogen gas to jointly increase the pressure inside the protective chamber. When the pressure exceeds the working pressure of the back pressure valve, the mixture is reheated through the vaporizer and then discharged. Subsequently, under the action of the back pressure valve, the structurally failed liquid hydrogen test bottle will reach a high-pressure state together with the inside of the protective chamber. At this time, the second liquid hydrogen valve and the first exhaust valve are opened, and the remaining liquid hydrogen inside the liquid hydrogen test bottle will rapidly enter the liquid hydrogen receiving tank under the action of pressure and gravity, safely handling the remaining liquid hydrogen and eliminating the safety risks of the liquid hydrogen test bottle. Finally, the strength test of the liquid hydrogen test bottle is completed.

[0014] As a further description of the above technical solution: Before operating step S100, ensure that the test system has been replaced and that all valves are closed.

[0015] As a further description of the above technical solution: The liquid level height added in step S200 can be determined according to the actual situation.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This invention proposes a method of first pressurizing and then gradually adding liquid hydrogen, which effectively reduces the high liquid hydrogen consumption and risks associated with the traditional method of filling the tank with liquid hydrogen first and then pressurizing. A pressure- and gravity-driven liquid hydrogen receiving tank is installed at the bottom of the liquid hydrogen test bottle to receive the liquid hydrogen medium after structural failure, effectively preventing the liquid hydrogen medium from affecting the overall testing device. A temperature sensor is installed in the insulation layer to indirectly warn of the liquid hydrogen test bottle's strength, and multiple sets of vent pipes are installed to prevent overpressure explosions caused by the vaporization of liquid hydrogen inside the insulation layer in the event of structural failure. Combined with a vacuum pump and vacuum extraction pipeline, the thermal protection capability of the insulation layer can be effectively guaranteed. Attached Figure Description

[0017] Figure 1 This is a test system architecture diagram of a liquid hydrogen bottle testing device proposed in this invention; Figure 2 This is a flowchart illustrating the workflow of a liquid hydrogen bottle testing device according to the present invention.

[0018] Legend: 1. Pressurization pipeline; 2. Helium cylinder group; 3. First helium shut-off valve; 4. Second helium shut-off valve; 5. Third helium shut-off valve; 6. Liquid hydrogen pipeline; 7. Liquid hydrogen supply tank; 8. First liquid hydrogen valve; 9. Liquid hydrogen test bottle; 10. Second liquid hydrogen valve; 11. Liquid hydrogen receiving tank; 12. Discharge pipeline; 13. First exhaust valve; 14. Second exhaust valve; 15. Back pressure valve; 16. Vacuumer; 17. Vacuum pump pipeline; 18. Vacuum shut-off valve; 19. Vacuum pump; 20. Insulation layer; 21. Temperature sensor; 22. Exhaust pipe; 23. Gas collector; 24. Safety valve; 25. Protective chamber; 26. Signal line; 27. Controller. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 and Figure 2The present invention provides a technical solution: a liquid hydrogen cylinder testing device, comprising a pressurization pipeline 1, a liquid hydrogen pipeline 6, a liquid hydrogen test bottle 9, an exhaust pipeline 12, a vacuum pipeline 17, a vacuum shut-off valve 18, a vacuum pump 19, an insulation layer 20, a temperature sensor 21, an exhaust pipe 22, a gas collector 23, a safety valve 24, and a protective chamber 25. The front end of the pressurization pipeline 1 is connected to a helium cylinder group 2, and the rear end is divided into three branches. The first branch is connected in sequence to the first helium shut-off valve 3 and the protective chamber 25. The second branch is connected in sequence to the second helium shut-off valve 4 and the liquid hydrogen supply tank 7. The third branch is connected in sequence to the third helium shut-off valve 5 and the liquid hydrogen test bottle 9. The pressurization pipeline 1 provides high-pressure helium to the three components. The front end of the liquid hydrogen pipeline 6 is connected to the liquid hydrogen supply tank 7 and the first liquid hydrogen valve 8, and the rear end is divided into two branches. The first branch is connected to the liquid hydrogen test bottle 9, and the second branch is connected to the second liquid hydrogen valve 10 and the liquid hydrogen receiving tank 11 in sequence. The liquid hydrogen pipeline 6 provides liquid hydrogen medium to the liquid hydrogen test bottle 9, and can quickly transfer the liquid hydrogen inside the liquid hydrogen test bottle 9 to the liquid hydrogen receiving tank 11 when the liquid hydrogen test bottle 9 fails. The front end of the discharge pipeline 12 is divided into three branches. The first branch is connected to the liquid hydrogen receiving tank 11 and the first exhaust valve 13 in sequence. The second branch is connected to the liquid hydrogen test bottle 9 and the second exhaust valve 14 in sequence. The third branch is connected to the protective chamber 25 and the back pressure valve 15 in sequence. Then the three branches are merged and connected to the vaporizer 16. As the medium inside the pipeline heats up, the discharge is finally carried out at high altitude. The vacuum line 17 is connected in sequence to the protective chamber 25, the vacuum shut-off valve 18 and the vacuum pump 19. The vacuum line 17 can evacuate the protective chamber 25.

[0021] Specifically, such as Figure 1 As shown, the liquid hydrogen test bottle 9 is located at the upper part of the protective chamber 25, and the liquid hydrogen receiving tank 11 is located at the lower part of the protective chamber 25. When the liquid hydrogen test bottle 9 fails, the remaining liquid hydrogen can enter the liquid hydrogen receiving tank 11 through the liquid hydrogen pipeline 6 and the second liquid hydrogen valve 10 under the combined action of pressure and gravity.

[0022] Specifically, such as Figure 1 As shown, the liquid hydrogen test bottle 9 is equipped with an insulation layer 20 on the outside. The insulation layer 20 is equipped with a through-type exhaust pipe 22. Multiple exhaust pipes 22 converge to the gas collector 23 and are connected to the entire protective chamber 25 through the safety valve 24. When the liquid hydrogen test bottle 9 fails and produces liquid hydrogen, the vaporized liquid hydrogen can enter the protective chamber 25 through the exhaust pipe 22, the gas collector 23 and the safety valve 24, thus preventing an overpressure explosion between the liquid hydrogen test bottle 9 and the insulation layer 20.

[0023] Specifically, such as Figure 1As shown, temperature sensors 21 are installed on both sides of the exhaust pipe 22 and connected to the controller 27 via signal lines 26. When liquid hydrogen test bottle 9 fails and produces liquid hydrogen, the temperature difference between the temperature sensors 21 on both sides of the exhaust pipe 22 will increase rapidly, enabling rapid judgment of structural failure.

[0024] Specifically, such as Figure 1 As shown, multiple exhaust pipes 22 are arranged from top to bottom along the axial direction of the liquid hydrogen test bottle 9, which can determine the liquid level inside the liquid hydrogen test bottle 9 based on the value of the temperature sensor 21.

[0025] Specifically, such as Figure 1 As shown, liquid hydrogen pipeline 6 and its valves must be insulated to prevent liquid hydrogen from vaporizing and generating two-phase flow.

[0026] Specifically, such as Figure 1 As shown, the vacuum pump 19 adopts a multi-stage series arrangement to improve the vacuum level inside the protective chamber 25.

[0027] Specifically, such as Figure 1 and Figure 2 As shown, a liquid hydrogen cylinder testing method based on the above-mentioned liquid hydrogen cylinder testing device includes the following steps: Before testing, ensure that the test system has been replaced and that all valves are closed.

[0028] (1) Vacuuming stage: Open the vacuum shut-off valve 18 and start the vacuum pump 19. Under the action of the vacuum pump 19, the interior of the protective chamber 25 reaches a vacuum state, which can ensure that the insulation layer 20 is equipped with multiple exhaust pipes 22 to maintain a high-performance insulation state. Then close the vacuum shut-off valve 18 and the vacuum pump 19. (2) Strength test stage: Open the second helium shut-off valve 4, the first liquid hydrogen valve 8, and the second exhaust valve 14. High-pressure helium from helium cylinder group 2 first enters the liquid hydrogen supply tank 7. Driven by pressure, the liquid hydrogen inside the liquid hydrogen supply tank 7 enters the liquid hydrogen test bottle 9 through the first liquid hydrogen valve 8. The hydrogen generated during the filling process passes through the second exhaust valve 14 and the vaporizer 16 in sequence and is discharged at high altitude. The liquid level inside the liquid hydrogen test bottle 9 is monitored by the temperature sensor 21. When the liquid level reaches 1 / 3 of the height, the first liquid hydrogen valve 8 and the second exhaust valve 14 are closed. The third helium shut-off valve 5 is opened to raise the internal pressure of the liquid hydrogen test bottle 9 to the pressure required for the strength test. A strength test is conducted. Since there is less liquid hydrogen inside the liquid hydrogen test bottle 9 at this time, the impact of structural failure is also smaller. Subsequently, the third helium shut-off valve 5 is closed and the first liquid hydrogen valve 8 is opened. The second exhaust valve 14 is used to refill liquid hydrogen into the liquid hydrogen test bottle 9. When the liquid level reaches 2 / 3 of the height, the first liquid hydrogen valve 8 and the second exhaust valve 14 are closed, and the third helium shut-off valve 5 is opened to raise the internal pressure of the liquid hydrogen test bottle 9 to the pressure required for the strength test, and a second strength test is conducted. Finally, the third helium shut-off valve 5 is closed, the first liquid hydrogen valve 8 and the second exhaust valve 14 are opened, and liquid hydrogen is refilled into the liquid hydrogen test bottle 9. When the liquid level reaches 3 / 3 of the height, the first liquid hydrogen valve 8 and the second exhaust valve 14 are closed, and the third helium shut-off valve 5 is opened to raise the internal pressure of the liquid hydrogen test bottle 9 to the pressure required for the strength test, and a third strength test is conducted. By gradually increasing the liquid level height, the strength test of the liquid hydrogen test bottle 9 is completed, and the test results are more comprehensive. In addition, the liquid level height added each time can be determined according to the actual situation. (3) Structural failure handling stage: When the liquid hydrogen test bottle 9 fails, firstly, close the second helium shut-off valve 4, the third helium shut-off valve 5, the first liquid hydrogen valve 8, and the second exhaust valve 14. The liquid hydrogen flowing out due to the structural failure first enters the insulation layer 20. Because the temperature of the protective chamber 25 is high, the liquid hydrogen will quickly vaporize and enter the gas collector 23 through the exhaust pipe 22. When the pressure inside the gas collector 23 is higher than the set pressure of the safety valve 24, the hydrogen gas quickly enters the protective chamber 25. At the same time, the first helium shut-off valve 3 is opened, and high-pressure helium gas enters the protective chamber 25 and reacts with the vaporized hydrogen gas. The gas mixture increases the pressure inside the protective chamber 25. When the pressure exceeds the working pressure of the back pressure valve 15, the mixture is reheated by the vaporizer 16 and then discharged. Subsequently, under the action of the back pressure valve 15, the structurally failed liquid hydrogen test bottle 9 will reach a high-pressure state together with the inside of the protective chamber 25. At this time, the second liquid hydrogen valve 10 and the first exhaust valve 13 are opened, and the remaining liquid hydrogen inside the liquid hydrogen test bottle 9 will quickly enter the liquid hydrogen receiving tank 11 under the action of pressure and gravity, safely handling the remaining liquid hydrogen and eliminating the safety risks of the liquid hydrogen test bottle 9. Finally, the strength test of the liquid hydrogen test bottle 9 is completed.

[0029] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A liquid hydrogen cylinder testing device, characterized in that, The system includes a pressurization pipeline (1), a liquid hydrogen pipeline (6), a liquid hydrogen test bottle (9), an exhaust pipeline (12), a vacuum pipeline (17), a vacuum shut-off valve (18), a vacuum pump (19), an insulation layer (20), a temperature sensor (21), an exhaust pipe (22), a gas collector (23), a safety valve (24), and a protective chamber (25). The pressurization pipeline (1) is connected to a helium cylinder group (2) at the front end and is divided into three branches at the rear end. The first branch is connected to the first helium shut-off valve (3) and the protective chamber (25) in sequence. The second branch is connected to the second helium shut-off valve (4) and the liquid hydrogen supply tank (7) in sequence. The third branch is connected to the third helium shut-off valve (5) and the liquid hydrogen test bottle (9) in sequence. The pressurization pipeline (1) provides high-pressure helium to the three components. The liquid hydrogen pipeline (6) is connected to the liquid hydrogen supply tank (7) and the first liquid hydrogen valve (8) at the front end, and is divided into two branches at the rear end. The first branch is connected to the liquid hydrogen test bottle (9), and the second branch is connected to the second liquid hydrogen valve (10) and the liquid hydrogen receiving tank (11) in sequence. The liquid hydrogen pipeline (6) provides liquid hydrogen medium to the liquid hydrogen test bottle (9) and can quickly transfer the liquid hydrogen inside the liquid hydrogen test bottle (9) to the liquid hydrogen receiving tank (11) when the liquid hydrogen test bottle (9) fails. The front end of the discharge pipeline (12) is divided into three branches. The first branch is connected to the liquid hydrogen receiving tank (11) and the first exhaust valve (13) in sequence. The second branch is connected to the liquid hydrogen test bottle (9) and the second exhaust valve (14) in sequence. The third branch is connected to the protective chamber (25) and the back pressure valve (15) in sequence. Then the three branches are merged and connected to the vaporizer (16). The vaporizer heats up with the flowing medium inside the pipeline and finally discharges at high altitude. The vacuum pipeline (17) is connected in sequence to the protective chamber (25), the vacuum shut-off valve (18) and the vacuum pump (19), and the vacuum pipeline (17) can evacuate the protective chamber (25).

2. The liquid hydrogen cylinder testing device according to claim 1, characterized in that, The liquid hydrogen test bottle (9) is located at the upper part of the protective chamber (25), and the liquid hydrogen receiving tank (11) is located at the lower part of the protective chamber (25). When the liquid hydrogen test bottle (9) fails, the remaining liquid hydrogen can enter the liquid hydrogen receiving tank (11) through the liquid hydrogen pipeline (6) and the second liquid hydrogen valve (10) under the combined action of pressure and gravity.

3. A liquid hydrogen cylinder testing device according to claim 1 or 2, characterized in that, The liquid hydrogen test bottle (9) is provided with an insulation layer (20) on the outside. The insulation layer (20) is provided with a through exhaust pipe (22). Multiple exhaust pipes (22) converge to the gas collector (23) and are connected to the entire protective chamber (25) through the safety valve (24). When the liquid hydrogen test bottle (9) fails and produces liquid hydrogen, the vaporized liquid hydrogen can enter the protective chamber (25) through the exhaust pipe (22), the gas collector (23) and the safety valve (24) to avoid overpressure explosion between the liquid hydrogen test bottle (9) and the insulation layer (20).

4. The liquid hydrogen cylinder testing device according to claim 1, characterized in that, Temperature sensors (21) are provided on both sides of the exhaust pipe (22) and connected to the controller (27) via signal lines (26). When the liquid hydrogen test bottle (9) fails and produces liquid hydrogen, the temperature difference between the temperature sensors (21) on both sides of the exhaust pipe (22) will increase rapidly, thus enabling rapid judgment of structural failure.

5. A liquid hydrogen cylinder testing device according to claim 1 or 4, characterized in that, Multiple exhaust pipes (22) are arranged from top to bottom along the axial direction of the liquid hydrogen test bottle (9), and the liquid level inside the liquid hydrogen test bottle (9) can be determined according to the value of the temperature sensor (21).

6. The liquid hydrogen cylinder testing device according to claim 1, characterized in that, The liquid hydrogen pipeline (6) and its valves must be insulated.

7. The liquid hydrogen cylinder testing device according to claim 1, characterized in that, The vacuum pump (19) adopts a multi-stage series arrangement to improve the vacuum level inside the protective chamber (25).

8. The liquid hydrogen bottle testing method according to claim 1, characterized in that, The steps include the following: S100, Vacuuming stage: Open the evacuation shut-off valve (18), start the vacuum pump (19), and under the action of the vacuum pump (19), the interior of the protective chamber (25) reaches a vacuum state, which allows the insulation layer (20) to be equipped with multiple exhaust pipes (22) to still maintain a high-performance insulation state. Then close the evacuation shut-off valve (18) and the vacuum pump (19). S200, Strength Test Stage: Open the second helium shut-off valve (4), the first liquid hydrogen valve (8), and the second exhaust valve (14). High-pressure helium from the helium cylinder group (2) first enters the liquid hydrogen supply tank (7). Driven by pressure, the liquid hydrogen inside the liquid hydrogen supply tank (7) enters the liquid hydrogen test bottle (9) through the first liquid hydrogen valve (8). The hydrogen generated during the filling process passes through the second exhaust valve (14) and the vaporizer (16) in sequence and is discharged at high altitude. The liquid level inside the liquid hydrogen test bottle (9) is monitored using a temperature sensor (21). When the liquid level reaches 1 / 3 of the height, the first liquid hydrogen valve (8) and the second exhaust valve (14) are closed. The third helium shut-off valve (5) is opened to raise the internal pressure of the liquid hydrogen test bottle (9) to the pressure required for the strength test. A strength test is performed. Since there is less liquid hydrogen inside the liquid hydrogen test bottle (9) at this time, the impact of structural failure is also smaller. Subsequently, the valve is closed. Close the third helium shut-off valve (5), open the first liquid hydrogen valve (8) and the second exhaust valve (14), and add liquid hydrogen to the liquid hydrogen test bottle (9) again. When the liquid level reaches 2 / 3 of the height, close the first liquid hydrogen valve (8) and the second exhaust valve (14), open the third helium shut-off valve (5), and increase the internal pressure of the liquid hydrogen test bottle (9) to the pressure required for the strength test, and perform a second strength test. Finally, close the third helium shut-off valve (5), open the first liquid hydrogen valve (8) and the second exhaust valve (14), and add liquid hydrogen to the liquid hydrogen test bottle (9) again. When the liquid level reaches 3 / 3 of the height, close the first liquid hydrogen valve (8) and the second exhaust valve (14), open the third helium shut-off valve (5), and increase the internal pressure of the liquid hydrogen test bottle (9) to the pressure required for the strength test, and perform a third strength test. The strength test of the liquid hydrogen test bottle (9) is completed by gradually increasing the liquid level height. S300, Structural Failure Handling Stage: When the liquid hydrogen test bottle (9) fails, firstly, close the second helium shut-off valve (4), the third helium shut-off valve (5), the first liquid hydrogen valve (8), and the second exhaust valve (14). The liquid hydrogen flowing out due to the structural failure first enters the insulation layer (20). Since the temperature of the protective chamber (25) is high, the liquid hydrogen will quickly vaporize and enter the gas collector (23) through the exhaust pipe (22). When the pressure inside the gas collector (23) is higher than the set pressure of the safety valve (24), the hydrogen quickly enters the protective chamber (25). At the same time, the first helium shut-off valve (3) is opened, and the high-pressure helium enters the protective chamber (25) and mixes with the vaporized hydrogen to increase the pressure inside the protective chamber (25). When the pressure is higher than the working pressure of the back pressure valve (15), the mixture is discharged after being reheated by the vaporizer (16). Subsequently, under the action of the back pressure valve (15), the liquid hydrogen test bottle (9) with structural failure will reach a high pressure state together with the interior of the protective chamber (25). At this time, the second liquid hydrogen valve (10) and the first exhaust valve (13) are opened, and the remaining liquid hydrogen inside the liquid hydrogen test bottle (9) will quickly enter the liquid hydrogen receiving tank (11) under the action of pressure and gravity.

9. The liquid hydrogen bottle testing method according to claim 8, characterized in that, Before operating step S100, ensure that the test system has been replaced and that all valves are in the closed state.

10. A liquid hydrogen bottle testing method according to claim 8, characterized in that, The liquid level height added in step S200 can be determined according to the actual situation.

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