Device and method for testing airtightness of hydrogen pipeline of hydrogen fuel vehicle

Abstract

The invention discloses a hydrogen fuel vehicle hydrogen pipeline airtightness test device and method. The device comprises a gas booster pump and a boosting pipeline, wherein a gas outlet of the gas booster pump is communicated with a gas inlet of the boosting pipeline; a hydrogenation gun is arranged at a gas outlet of the pressurization pipeline and used for being connected with a vehicle hydrogenation port and providing pressurization gas for a vehicle through the vehicle hydrogenation port; the pressurizing pipeline is sequentially provided with a pressure regulating valve and a third pressure gauge from the air inlet to the air outlet; the pressure regulating valve is used for regulating the pressure of gas output by the pressurizing pipeline; the third pressure gauge is used for detecting the gas pressure output by the pressurization pipeline. According to the invention, the gas pressure intensity is adjusted by using the gas booster pump and the pressure regulating valve, the gas pressure intensity of the hydrogen pipeline of the hydrogen fuel vehicle in actual work can be simulated, and the reliability of a test result is improved; moreover, the gas leakage condition is observed by using the third pressure gauge, and based on the sensitivity of the third pressure gauge, the problem that tiny leakage in the hydrogen pipeline of the hydrogen fuel vehicle may be missed is solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to air tightness detection technology, and in particular to an air tightness test device and method for hydrogen pipelines of hydrogen fuel vehicles. Background Art

[0002] During the assembly process of a hydrogen fuel cell vehicle, components such as the hydrogen filling port, hydrogen cylinder, one-way valve, pressure reducing valve, safety valve, and sensors must be connected using piping, which is then connected to the fuel cell or engine. During the pilot production phase, piping connections were mostly made by hand-bending and matching on-site, resulting in inconsistent installation quality. Hydrogen is highly permeable and easily leaks, threatening vehicle operation safety.

[0003] Therefore, it is necessary to inspect the air tightness of the hydrogen pipeline after the vehicle hydrogen pipeline is installed and before hydrogen is added to ensure that the hydrogen pipeline is airtight. The current method is mainly to connect the hydrogen pipeline to a fixed gas source and spray a leak tester at each pipeline connection to determine the air tightness of the hydrogen pipeline. The main problems with this method are: 1. Spraying and observing the leak tester can easily miss some small leaks; 2. The fixed gas source pressure in the workshop is generally 3-5 bar (0.3-0.5 MPa), and the actual working pressure of the hydrogen pipeline can reach up to 70 MPa. The leak test results are difficult to prove the air tightness of the pipeline under high pressure; 3. The leak test operation is complicated and inconvenient. Summary of the Invention

[0004] The present invention provides a device and method for testing the air tightness of hydrogen pipelines of hydrogen fuel vehicles, so as to solve the problem that the air tightness test gas pressure is low and small gas leaks are easily missed.

[0005] In a first aspect, an embodiment of the present invention provides a hydrogen pipeline air tightness test device for a hydrogen fuel vehicle, comprising a gas booster pump and a booster pipeline, wherein the gas outlet of the gas booster pump is connected to the gas inlet of the booster pipeline;

[0006] The gas outlet of the pressurized pipeline is provided with a hydrogenation gun, which is used to connect to the vehicle hydrogenation port and provide pressurized gas to the vehicle through the vehicle hydrogenation port;

[0007] The boost pipeline is provided with a pressure regulating valve and a third pressure gauge in sequence from the air inlet to the air outlet;

[0008] The pressure regulating valve is used to adjust the gas pressure output by the boost pipeline;

[0009] The third pressure gauge is used to detect the pressure of the gas output by the boost pipeline.

[0010] Optionally, a safety pipeline is further included, wherein the air inlet of the safety pipeline is connected to the boost pipeline, and the air outlet is connected to the outside;

[0011] The safety pipeline is provided with a safety valve, and the safety valve is used to connect the boost pipeline to the outside when the gas pressure in the boost pipeline exceeds a first preset gas pressure threshold, and the first preset gas pressure threshold is adjustable.

[0012] Optionally, it further comprises an exhaust pipeline, wherein the air inlet of the exhaust pipeline is connected to the pressurization pipeline, and the air outlet is connected to the outside;

[0013] The exhaust pipeline is provided with a manual exhaust valve, and the manual exhaust valve is used to control the communication or disconnection between the boost pipeline and the outside.

[0014] Optionally, a four-way pipe connector is further included, and the four interfaces of the four-way pipe connector are respectively connected to the air outlet of the gas booster pump, the air inlet of the boosting pipeline, the air inlet of the safety pipeline and the air inlet of the exhaust pipeline.

[0015] Optionally, it further comprises a working gas source pipeline and a driving gas source pipeline; the air inlet of the working gas source pipeline is used to receive the working gas source, and the air outlet is communicated with the working gas source air inlet of the gas booster pump; the air inlet of the driving gas source pipeline is used to receive the driving gas source, and the air outlet is communicated with the driving gas source air inlet of the gas booster pump;

[0016] The driving gas source pipeline is provided with a first pressure gauge and a first control valve in sequence from the air inlet to the air outlet; the first control valve is used to control the connection or cutoff between the driving gas source inlet of the gas booster pump and the driving gas source, and the first pressure gauge is used to detect the gas pressure in the driving gas source pipeline;

[0017] The working gas source pipeline is provided with a second pressure gauge and a second control valve in sequence from the air inlet to the air outlet; the second control valve is used to control the connection or disconnection between the working gas source inlet of the gas booster pump and the working gas source, and the second pressure gauge is used to detect the gas pressure in the working gas source pipeline.

[0018] In a second aspect, an embodiment of the present invention further provides a method for testing the air tightness of a hydrogen pipeline of a hydrogen fuel vehicle, which is performed using the hydrogen pipeline air tightness testing device for a hydrogen fuel vehicle described in any one of the first aspects;

[0019] The air tightness test method includes a vehicle pipeline air tightness detection stage; the vehicle hydrogen pipeline air tightness detection stage includes a first preparation stage and multiple first test stages, the first preparation stage is located before the first test stage;

[0020] The first preparation stage includes:

[0021] Connect the hydrogenation gun to the vehicle's hydrogenation port and turn on the hydrogenation gun;

[0022] The first testing phase includes:

[0023] activating the gas booster pump to provide pressurized gas to the vehicle through the vehicle hydrogen refueling port;

[0024] Regulating the gas pressure output from the boosting pipeline to a first target output pressure using the pressure regulating valve, and turning off the gas boosting pump to maintain the pressure for a first preset time;

[0025] When a first pressure drop ratio of the gas pressure output from the boost pipeline detected by the third pressure gauge within the first preset time is greater than or equal to a first preset pressure drop ratio threshold, determining that the air tightness of the vehicle hydrogen pipeline does not meet the requirement;

[0026] Among them, the first pressure drop ratio is the ratio of the pressure difference between the first initial pressure and the first termination pressure to the first initial pressure, the first initial pressure is the gas pressure output by the boost pipeline at the initial moment of the first preset time, and the first termination pressure is the gas pressure output by the boost pipeline at the termination moment of the first preset time; the first target output pressure of each first test stage increases successively and has a preset pressure difference.

[0027] Optionally, when a first pressure drop ratio of the gas pressure output from the boost pipeline detected by the third pressure gauge within the first preset time is greater than or equal to a first preset pressure drop ratio threshold, after determining that the air tightness of the vehicle hydrogen pipeline does not meet the requirement, the method further includes:

[0028] Find the leak point;

[0029] The leakage point is sealed, and the gas pressure output from the boosting pipeline of the pressure regulating valve is readjusted to the first target output pressure. The gas boosting pump is turned off and the pressure is maintained for a first preset time until the first pressure drop ratio of the gas pressure output from the boosting pipeline detected by the third pressure gauge within the first preset time is less than the first preset pressure drop ratio threshold.

[0030] Optionally, the air tightness test method further includes a test device air tightness test stage; the test device air tightness test stage is before the vehicle pipeline air tightness test stage;

[0031] The airtightness detection phase of the test device includes a second preparation phase and a second test phase, wherein the second preparation phase is located before the second test phase;

[0032] The second preparation stage includes:

[0033] Close the hydrogenation gun;

[0034] The second testing phase includes:

[0035] Starting the gas booster pump;

[0036] Regulating the gas pressure output from the boosting pipeline to a second target output pressure using the pressure regulating valve, and turning off the gas boosting pump to maintain the pressure for a second preset time;

[0037] When a second pressure drop ratio of the gas pressure output from the boosting pipeline detected by the third pressure gauge within the second preset time is greater than or equal to a second preset pressure drop ratio threshold, determining that the air tightness of the test device does not meet the requirement;

[0038] Among them, the second pressure drop ratio is the ratio of the pressure difference between the second initial pressure and the second ending pressure to the second initial pressure, the second initial pressure is the gas pressure output by the boost pipeline at the initial moment of the second preset time, and the second ending pressure is the gas pressure output by the boost pipeline at the ending moment of the second preset time.

[0039] Optionally, the hydrogen pipeline air tightness test device for hydrogen fuel vehicle further includes a safety pipeline, the air inlet of the safety pipeline is connected to the boost pipeline, and the air outlet is connected to the outside;

[0040] The safety pipeline is provided with a safety valve, and the safety valve is used to connect the boosting pipeline to the outside when the gas pressure in the boosting pipeline exceeds a first preset gas pressure threshold, and the first preset gas pressure threshold is adjustable;

[0041] The air tightness test method further includes a test device function test stage; the test device function test stage is before the vehicle pipeline air tightness test stage;

[0042] The functional detection phase of the test device includes a third preparation phase and a third test phase, wherein the third preparation phase is located before the third test phase;

[0043] The third preparation stage includes:

[0044] Close the hydrogenation gun;

[0045] Setting a first preset gas pressure threshold of the safety valve;

[0046] The third testing phase includes:

[0047] Starting the gas booster pump;

[0048] Utilizing the pressure regulating valve to adjust the gas pressure outputted by the boosting pipeline to exceed the first preset gas pressure threshold;

[0049] When the gas pressure output from the boost pipeline detected by the third pressure gauge is higher than the first preset gas pressure threshold, the safety valve releases pressure to determine that the safety valve functions normally.

[0050] Optionally, the hydrogen fuel vehicle hydrogen pipeline air tightness test device further includes an exhaust pipeline, the air inlet of the exhaust pipeline is connected to the boost pipeline, and the air outlet is connected to the outside;

[0051] A manual drain valve is provided on the drain pipeline, and the manual drain valve is used to control the connection or disconnection between the boost pipeline and the outside;

[0052] Before starting the gas booster pump to provide pressurized gas to the vehicle through the vehicle hydrogen refueling port, after using the pressure regulating valve to adjust the gas pressure output from the boost pipeline to exceed the first preset gas pressure threshold, the method further includes:

[0053] Open the manual drain valve;

[0054] When the gas pressure output from the boost pipeline detected by the third pressure gauge drops below a second preset gas pressure threshold within a third preset time, it is determined that the manual drain valve functions normally.

[0055] The hydrogen pipeline air tightness test device for hydrogen fuel vehicles provided in an embodiment of the present invention can simulate the gas pressure in the actual operation of the hydrogen pipeline of a hydrogen fuel vehicle by using a gas booster pump and a pressure regulating valve to adjust the gas pressure, and can meet the requirement that the maximum working pressure of the hydrogen pipeline of a hydrogen fuel vehicle is 70Mpa, thereby improving the reliability of the test results. By using a third pressure gauge to observe the gas leakage of the hydrogen pipeline of a hydrogen fuel vehicle, based on the sensitivity of the third pressure gauge, the problem that small leaks in the hydrogen pipeline of a hydrogen fuel vehicle may be missed is solved. In addition, during the actual test, the air tightness test can be completed by simply connecting the hydrogen filling gun in the test device to the hydrogen filling port of the vehicle, making the operation easier and effectively improving production efficiency and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A schematic structural diagram of a hydrogen pipeline air tightness test device for a hydrogen fuel vehicle provided by an embodiment of the present invention;

[0057] Figure 2 A schematic structural diagram of another hydrogen pipeline air tightness test device for hydrogen fuel vehicles provided by an embodiment of the present invention;

[0058] Figure 3 A schematic structural diagram of another hydrogen pipeline air tightness test device for hydrogen fuel vehicles provided in an embodiment of the present invention;

[0059] Figure 4A schematic flow chart of the first test phase of the vehicle pipeline air tightness detection phase in a method for testing the air tightness of hydrogen pipelines in a hydrogen fuel vehicle provided by an embodiment of the present invention;

[0060] Figure 5 A schematic flow chart of the second test phase of the air tightness detection phase of the test device in another method for testing the air tightness of the hydrogen pipeline of a hydrogen fuel vehicle provided by an embodiment of the present invention;

[0061] Figure 6 A schematic flow chart of the third test phase of the test device function detection phase in another hydrogen pipeline air tightness test method for hydrogen fuel vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0063] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present invention are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be formed directly "on" or "under" another element, but can also be formed indirectly "on" or "under" another element through an intermediate element. The terms "first", "second", etc. are only used for descriptive purposes and do not indicate any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] The term "including" and its variations used in the present invention are open inclusions, that is, "including but not limited to." The term "based on" means "based at least in part on." The term "one embodiment" means "at least one embodiment."

[0065] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or mutual dependence.

[0066] It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0067] Figure 1 A schematic diagram of a hydrogen pipeline air tightness test device for a hydrogen fuel vehicle provided in an embodiment of the present invention is shown in FIG. Figure 1 As shown, the air tightness test device includes a gas booster pump 10 and a booster pipeline 20. The air outlet of the gas booster pump 10 is connected to the air inlet of the booster pipeline 20. The air outlet of the booster pipeline 20 is provided with a hydrogenation gun 30. The hydrogenation gun 30 is used to connect to the vehicle hydrogenation port and provide pressurized gas to the vehicle through the vehicle hydrogenation port. The booster pipeline 20 is sequentially provided with a pressure regulating valve 201 and a third pressure gauge 202 from the air inlet to the air outlet. The pressure regulating valve 201 is used to adjust the gas pressure output by the booster pipeline 20; the third pressure gauge 202 is used to detect the gas pressure output by the booster pipeline 20.

[0068] Specifically, refer to Figure 1 The vehicle hydrogen filling port 2 is located outside the hydrogen pipeline air tightness test device 1 of the hydrogen fuel vehicle. The actual working pressure of the hydrogen pipeline of the hydrogen fuel vehicle can reach up to 70Mpa. Therefore, when performing the air tightness test on the hydrogen pipeline, the gas pressure must be changed within a range of less than or equal to 70Mpa to ensure the reliability of the hydrogen pipeline of the hydrogen fuel vehicle. Figure 1 The airtightness testing device 1 includes a gas booster pump 10 and a booster pipeline 20, which are used to adjust the gas pressure in the hydrogen pipeline of a hydrogen fuel vehicle so that the gas pressure meets actual requirements. The gas outlet of the gas booster pump 10 is connected to the gas inlet of the booster pipeline 20. In addition, a hydrogenation gun 30 is provided at the gas outlet of the booster pipeline 20. The hydrogenation gun 30 is used to connect to the vehicle's hydrogen filling port 2 and provide pressurized gas to the vehicle through the vehicle's hydrogen filling port 2. When performing an airtightness test on the hydrogen pipeline of a hydrogen fuel vehicle, the airtightness of the hydrogen pipeline of the hydrogen fuel vehicle can be determined by simply supplying pressurized gas to the hydrogen pipeline of the hydrogen fuel vehicle through the hydrogenation gun 30.

[0069] Furthermore, the boosting pipeline 20 is provided with a pressure regulating valve 201 and a third pressure gauge 202 in sequence from the air inlet to the air outlet. The pressure regulating valve 201 is used to adjust the gas pressure output by the boosting pipeline 20, and the third pressure gauge 202 is used to detect the gas pressure output by the boosting pipeline 20. Specifically, refer to Figure 1 , the pressure regulating valve 201 can adjust the gas pressure in the air tightness test device according to the actual working pressure of the hydrogen pipeline of the hydrogen fuel vehicle, and output gas of a fixed pressure. The third pressure gauge 202 is set at the gas outlet of the pressure regulating valve 201, so as to detect whether the gas pressure output by the pressure regulating valve 201 meets the air tightness test requirements of the hydrogen pipeline of the hydrogen fuel vehicle. When the hydrogen refueling gun 30 is connected to the vehicle hydrogen refueling port 2, the air tightness of the hydrogen pipeline of the hydrogen fuel vehicle can be judged according to the pressure value displayed by the third pressure gauge 202, and because the third pressure gauge 202 can display the gas pressure value in real time and has high sensitivity, even small leaks in the hydrogen pipeline of the hydrogen fuel vehicle can be detected.

[0070] The embodiment of the present invention uses a gas booster pump and a pressure regulating valve to adjust the gas pressure, which can simulate the gas pressure in the actual operation of the hydrogen pipeline of a hydrogen fuel vehicle, and can meet the requirement that the maximum working pressure of the hydrogen pipeline of a hydrogen fuel vehicle is 70Mpa, thereby improving the reliability of the test results. By using a third pressure gauge to observe the gas leakage of the hydrogen pipeline of a hydrogen fuel vehicle, based on the sensitivity of the third pressure gauge, the problem that small leaks in the hydrogen pipeline of a hydrogen fuel vehicle may be missed is solved. In addition, during the actual test, the air tightness test can be completed by simply connecting the hydrogen gun in the test device to the vehicle's hydrogen filling port, making the operation easier and effectively improving production efficiency and product quality.

[0071] Optionally, Figure 2 A schematic diagram of the structure of another hydrogen fuel vehicle hydrogen pipeline air tightness test device provided in an embodiment of the present invention is shown as follows: Figure 2 As shown, the air tightness testing device 1 also includes a safety pipeline 40, the air inlet of the safety pipeline 40 is connected to the boost pipeline 20, and the air outlet is connected to the outside; a safety valve 401 is provided on the safety pipeline 40, and the safety valve 401 is used to connect the boost pipeline 20 to the outside when the gas pressure in the boost pipeline 20 exceeds a first preset gas pressure threshold, and the first preset gas pressure threshold is adjustable.

[0072] Specifically, in a hydrogen fuel vehicle system, the main function of the safety valve 401 is to automatically release gas when the system pressure rises abnormally to prevent the pipeline, hydrogen storage bottle or other components from rupturing due to overpressure, thereby avoiding potential explosion or leakage accidents. Under normal circumstances, the safety valve 401 is in a closed state. Figure 2 The air inlet of the safety line 40 is connected to the boost line 20, and the air outlet is connected to the outside. A first preset gas pressure threshold is set in the safety valve 401. This first preset gas pressure threshold can be adjusted according to the maximum operating pressure of the hydrogen fuel vehicle. It can be understood that the first preset gas pressure threshold should be greater than the maximum operating pressure of the hydrogen fuel vehicle and less than the maximum gas pressure that each component in the hydrogen pipeline of the hydrogen fuel vehicle can withstand. When the hydrogen pipeline of the hydrogen fuel vehicle is tested for air tightness, the safety valve 401 monitors the gas pressure in the boost line 20 in real time based on the set first preset gas pressure threshold. When the gas pressure in the boost line 20 exceeds the first preset gas pressure threshold, the safety valve 401 automatically opens and discharges the excess gas in the boost line 20 to the outside through the air outlet of the safety valve 401, thereby reducing the gas pressure in the boost line 20 and ensuring the safety of the hydrogen fuel vehicle system.

[0073] Optionally, continue to refer to Figure 2The air tightness test device 1 also includes an exhaust pipe 50, the air inlet of the exhaust pipe 50 is connected to the boost pipe 20, and the air outlet is connected to the outside; a manual exhaust valve 501 is provided on the exhaust pipe 50, and the manual exhaust valve 501 is used to control the conduction or cutoff of the boost pipe 20 with the outside.

[0074] Specifically, when performing an air tightness test on the hydrogen pipeline of a hydrogen fuel vehicle system, the gas pressure can be adjusted by the gas booster pump 10 and the pressure regulating valve 201, and monitored by the third pressure gauge 202. When the gas pressure value displayed by the third pressure gauge 202 is greater than the desired pressure value but less than the first preset gas pressure threshold, the excess gas in the boost pipeline 20 needs to be discharged to the outside through the gas outlet of the exhaust pipeline 50. The manual exhaust valve 501 is opened until the gas pressure displayed by the third pressure gauge 202 reaches the desired pressure value, and then the manual exhaust valve 501 is closed, thereby ensuring that the gas pressure in the air tightness test device 1 meets the requirements. In addition, when the air tightness test of the hydrogen pipeline of the hydrogen fuel vehicle system is completed, the manual exhaust valve 501 needs to be opened to completely discharge the gas in the air tightness test device to the outside through the gas outlet of the exhaust pipeline 50.

[0075] Optionally, refer to Figure 2 The air tightness test device 1 also includes a four-way pipe connector 60, the four interfaces of which are respectively connected to the air outlet of the gas booster pump 10, the air inlet of the boosting pipeline 20, the air inlet of the safety pipeline 40 and the air inlet of the exhaust pipeline 50.

[0076] Specifically, continue to refer to Figure 2 The gas passing through the gas booster pump 10 enters the boost line 20, the safety line 40, and the exhaust line 50 through the four-way pipe connector 60. Therefore, the gas in the boost line 20, the safety line 40, and the exhaust line 50 has the same pressure. When the pressure regulating valve 201 in the boost line 20 adjusts the gas pressure, the gas pressure in the safety line 40 and the exhaust line 50 will also change accordingly. When the safety valve 401 or the manual exhaust valve 501 is opened, the gas pressure in the boost line 20 will also decrease accordingly.

[0077] The embodiment of the present invention achieves dynamic adjustment of gas pressure by adding a four-way pipe connector and an exhaust pipeline in the air tightness test device, further meeting the actual working requirements of the hydrogen pipeline of the hydrogen fuel vehicle system. In addition, by adding a safety pipeline and setting a first preset gas pressure threshold according to the actual working gas pressure of the hydrogen pipeline of the hydrogen fuel vehicle system, the safety and reliability of the air tightness test device are ensured.

[0078] Optionally, Figure 3A structural diagram of another hydrogen fuel vehicle hydrogen pipeline air tightness test device provided in an embodiment of the present invention is shown as follows: Figure 3 As shown, the air tightness test device 1 also includes a working air source pipeline 70 and a driving air source pipeline 80; the air inlet of the working air source pipeline 70 is used to receive the working air source 3, and the air outlet is connected to the working air source inlet 101 of the gas booster pump 10; the air inlet of the driving air source pipeline 80 is used to receive the driving air source 4, and the air outlet is connected to the driving air source inlet 102 of the gas booster pump 10.

[0079] The driving gas source pipeline 80 is provided with a first pressure gauge 801 and a first control valve 802 in sequence from the air inlet to the air outlet; the first control valve 802 is used to control the connection or disconnection between the driving gas source inlet 102 of the gas booster pump 10 and the driving gas source 4, and the first pressure gauge 801 is used to detect the gas pressure in the driving gas source pipeline 80.

[0080] The working gas source pipeline 70 is provided with a second pressure gauge 701 and a second control valve 702 in sequence from the air inlet to the air outlet; the second control valve 702 is used to control the connection or disconnection between the working gas source inlet 101 of the gas booster pump 10 and the working gas source 3, and the second pressure gauge 701 is used to detect the gas pressure in the working gas source pipeline.

[0081] Specifically, if Figure 3 As shown, the gas booster pump 10 is provided with a working gas source inlet 101 and a driving gas source inlet 102 at the air inlet. The air inlet of the driving gas source pipeline 80 is used to receive the driving gas source 4, and the air outlet is connected to the driving gas source inlet 102 of the gas booster pump 10, wherein the driving gas source 4 is arranged outside the air tightness test device 1 and is used to provide power for the gas booster pump 10. For example, the driving gas source 4 can be compressed air or a nitrogen cylinder. The air inlet of the working gas source pipeline 70 is used to receive the working gas source 3, and the air outlet is connected to the working gas source inlet 101 of the gas booster pump 10, wherein the working gas source 3 is arranged outside the air tightness test device 1 and is the working medium used for air tightness testing. For example, the working gas source 3 can be nitrogen or helium.

[0082] Furthermore, when performing an air tightness test, the first control valve 802, the second control valve 702, and the gas booster pump 10 are opened simultaneously. The working gas source 3 enters the working gas source inlet 101 of the gas booster pump 10 after passing through the second pressure gauge 701, and the driving gas source 4 enters the driving gas source inlet 102 of the gas booster pump 10 after passing through the first pressure gauge 801. The gas booster pump 10 pressurizes the working gas source under the action of the driving gas source 4. Therefore, the gas pressures of the driving gas source 4 and the working gas source 3 both affect the gas pressure at the gas outlet of the gas booster pump 10. In addition, an exhaust outlet 103 is also provided in the gas booster pump 10 for discharging the driving gas source 4 after energy transfer to the external environment.

[0083] The embodiment of the present invention connects the air tightness test device with an external working gas source and a driving gas source to provide a working medium and a driving power for the gas booster pump. By setting a first control valve and a second control valve, the gas of the working gas source and the driving gas source can be respectively conducted and cut off. By setting a first pressure gauge and a second pressure gauge, the gas pressure generated by the working gas source and the driving gas source can be monitored in real time. When the gas pressure is too high, the gas input of the working gas source and the driving gas source to the gas booster pump is cut off by the first control valve and the second control valve, thereby improving the safety of the air tightness test device.

[0084] Based on the hydrogen fuel vehicle hydrogen pipeline air tightness test device of any of the above embodiments, the present invention also provides a hydrogen fuel vehicle hydrogen pipeline air tightness detection phase test method, the air tightness test method includes a vehicle pipeline air tightness detection phase, wherein the vehicle hydrogen pipeline air tightness detection phase includes a first preparation phase and multiple first test phases, and the first preparation phase is located before the first test phase.

[0085] The first preparation stage may include: connecting the hydrogen refueling gun to the hydrogen refueling port of the vehicle and turning on the hydrogen refueling gun.

[0086] Specifically, if Figure 3 As shown, before testing the air tightness of the hydrogen pipeline of a hydrogen fuel vehicle, it is first necessary to connect the air tightness test device to the vehicle hydrogen filling port 2 through the hydrogen filling gun 30, and open the hydrogen filling gun 30 to allow gas to enter the hydrogen pipeline of the hydrogen fuel vehicle.

[0087] Figure 4 This is a flow chart of the first test phase of the vehicle pipeline air tightness detection phase in a hydrogen fuel vehicle hydrogen pipeline air tightness test method provided by an embodiment of the present invention, with reference to Figure 4 , this first testing phase may include:

[0088] S101: Start a gas booster pump to provide pressurized gas to the vehicle through the vehicle's hydrogen filling port.

[0089] Specifically, refer to Figure 3Before starting the gas booster pump 10, it is necessary to control the first control valve 802, the second control valve 702, and the manual drain valve 501 to the closed state. At the same time, a first preset gas pressure threshold is set in the safety valve 401. The first gas pressure threshold is greater than the actual maximum operating pressure of the hydrogen fuel vehicle and less than the maximum gas pressure that each component in the hydrogen pipeline of the hydrogen fuel vehicle can withstand. For example, the first gas pressure threshold can be 105 MPa. Then, the airtightness test device 1 is connected to the working gas source 3 and the driving gas source 4. The working gas source 3 can be a nitrogen cylinder, and the driving gas source 4 can be compressed air or a nitrogen cylinder. Finally, the first control valve 802, the second control valve 702 and the gas booster pump 10 are opened in sequence, and the working gas source 3 enters the working gas source inlet 101 of the gas booster pump 10 through the second control valve 702, and the driving gas source 4 enters the driving gas source inlet 102 of the gas booster pump 10 through the first control valve 802. At the same time, the second pressure gauge 701 and the first pressure gauge 801 respectively monitor the gas pressures of the working gas source 3 and the driving gas source 4 in real time. Under the action of the driving gas source 4, the gas booster pump 10 pressurizes the working gas source 3, thereby providing pressurized gas to the vehicle through the vehicle hydrogen refueling port 2.

[0090] S102: Regulate the gas pressure output from the boosting pipeline to a first target output pressure using a pressure regulating valve, and turn off the gas boosting pump to maintain the pressure for a first preset time.

[0091] Specifically, since the hydrogen pipeline of a hydrogen fuel vehicle may operate at any gas pressure, the gas pressure output from the boost pipeline 20 can be changed in real time to a first target output pressure by adjusting the pressure regulating valve 201. The first target output pressure is not specifically limited in the embodiment of the present invention. In an optional embodiment, the first target output pressure can be 30 MPa, 40 MPa, 50 MPa, or 70 MPa. After the pressure regulating valve adjusts the gas pressure output from the boost pipeline to the first target output pressure, the first control valve 802, the second control valve 702, and the gas booster pump 10 are closed, and the manual control valve 501 remains closed, thereby ensuring that the pressure of the boosted gas in the airtightness test device 1 is stable and avoiding changes in gas pressure due to gas circulation in the device. This pressure maintaining state is maintained for a first preset time. For example, the first preset time is 30 minutes or longer, thereby improving the reliability of the test results.

[0092] S103: When a first pressure drop ratio of the gas pressure output from the boost pipeline detected by the third pressure gauge within a first preset time is greater than or equal to a first preset pressure drop ratio threshold, determine that the air tightness of the vehicle hydrogen pipeline does not meet the requirements.

[0093] Among them, the first pressure drop ratio is the ratio of the pressure difference between the first initial pressure and the first termination pressure to the first initial pressure, the first initial pressure is the gas pressure output by the boost pipeline at the initial moment of the first preset time, and the first termination pressure is the gas pressure output by the boost pipeline at the termination moment of the first preset time; the first target output pressure of each first test stage increases successively and has a preset pressure difference.

[0094] Specifically, a first preset pressure drop ratio threshold can be set based on the hydrogen fuel vehicle's airtightness requirements, wherein a smaller the first preset pressure drop ratio threshold, the higher the hydrogen fuel vehicle's airtightness requirements. For example, the first preset pressure drop ratio threshold can be 0.25%. After the airtightness test device 1 is turned on to maintain pressure, the gas pressure value detected by the third pressure gauge 202 is observed, and the gas pressure value output by the boost pipeline 20 at the initial moment of the first preset time is recorded as the first initial pressure value. If there is a gas leak in the hydrogen pipeline of the hydrogen fuel vehicle, the gas pressure value detected by the third pressure gauge 20 will decrease. If the hydrogen pipeline of the hydrogen fuel vehicle is airtight, the gas pressure value detected by the third pressure gauge 20 remains substantially stable. At the end of the first preset time, the gas pressure value output by the boost pipeline 20 is recorded as the first end pressure, and the first initial pressure is compared with the first end pressure. If the first pressure drop ratio is greater than or equal to the first preset pressure drop ratio threshold, it is determined that the vehicle's hydrogen pipeline does not meet the airtightness requirements.

[0095] It should be noted that meeting the airtightness requirements for hydrogen pipelines in hydrogen fuel cell vehicles at low gas pressures does not necessarily mean they will also meet the airtightness requirements at higher gas pressures. Therefore, during the first test phase, the first target output pressure must be gradually increased until the first target output pressure reaches the maximum gas pressure at which the hydrogen fuel cell vehicle actually operates. It is understood that different first target output pressures should have different preset pressure differentials, thereby having the same first preset pressure drop ratio threshold.

[0096] Optionally, when a first pressure drop ratio of the gas pressure output from the boost pipeline 20 detected by the third pressure gauge 202 within a first preset time is greater than or equal to a first preset pressure drop ratio threshold, after determining that the air tightness of the vehicle hydrogen pipeline does not meet the requirement, the method further includes:

[0097] S104, find the leakage point;

[0098] S105. Seal the leakage point, readjust the gas pressure output from the boosting pipeline of the pressure regulating valve to a first target output pressure, turn off the gas boosting pump, and maintain the pressure for a first preset time until a first pressure drop ratio of the gas pressure output from the boosting pipeline detected by a third pressure gauge within the first preset time is less than a first preset pressure drop ratio threshold.

[0099] Specifically, the leakage point of the hydrogen pipeline of a hydrogen fuel vehicle is usually at the pipeline connection point due to loose connection, which leads to gas leakage. After finding the leakage point, the leakage point position is re-sealed and re-connected, and then the hydrogen pipeline of the hydrogen fuel vehicle is re-tested for air tightness, that is, the output gas pressure of the boost pipeline 20 of the pressure regulating valve 201 is readjusted to the first target output pressure, and the gas booster pump 10 is turned off, the pressure is maintained for the first preset time, and the change in the gas pressure detected by the third pressure gauge 202 is observed. If the gas pressure value detected by the third pressure gauge 202 decreases within the first preset time, and the first pressure drop ratio is still greater than or equal to the first preset pressure drop ratio threshold, it is necessary to find the leakage point again and seal the leakage point until the first pressure drop ratio of the gas pressure output from the boost pipeline detected by the third pressure gauge 202 within the first preset time is less than the first preset pressure drop ratio threshold. It is understandable that after the leakage point is sealed, the hydrogen pipeline of the hydrogen fuel vehicle still needs to be tested for airtightness at multiple first target output pressures in sequence until the first target output pressure is the maximum actual operating pressure of the hydrogen pipeline of the hydrogen fuel vehicle.

[0100] In this embodiment of the present invention, a third pressure gauge monitors changes in gas pressure before and after a first preset time, and sets a first preset pressure drop ratio threshold. If the first pressure drop ratio within the first preset time is greater than or equal to the first preset pressure drop ratio threshold, the vehicle's hydrogen pipeline is determined to be unfit for airtightness. Leaks are then identified and sealed, and the airtightness test is repeated until the first pressure drop ratio falls below the first preset pressure drop ratio threshold. By using a pressure regulating valve to stabilize the gas pressure output from the boost pipeline, the gas pressure during the airtightness test is closer to the actual operating gas pressure, ensuring the reliability of the test results.

[0101] Furthermore, based on the hydrogen pipeline air tightness test device for hydrogen fuel vehicles of any of the above embodiments, the present invention also provides a test method for the air tightness detection phase of the hydrogen pipeline air tightness test device for hydrogen fuel vehicles. The test method also includes a test device air tightness detection phase. The test device air tightness detection phase is before the vehicle pipeline air tightness detection phase, and may specifically include a second preparation phase and a second test phase. The second preparation phase is before the second test phase.

[0102] The second preparation stage may include: closing the hydrogenation gun.

[0103] Specifically, if Figure 3 As shown, when performing the air tightness test of the test device, the hydrogenation gun 30 needs to be closed to ensure that the air tightness test device 1 is disconnected from the vehicle hydrogenation port 2. At this time, if a gas leakage occurs, it is only necessary to find the leak point of the air tightness test device 1.

[0104] Figure 5A flow chart of the second test phase of the air tightness detection phase of the test device in another method for testing the air tightness of the hydrogen pipeline of a hydrogen fuel vehicle provided by an embodiment of the present invention is provided. Figure 5 , the second testing phase may include:

[0105] S201, start the gas booster pump.

[0106] Specifically, refer to Figure 3 Before starting the gas booster pump 10, it is necessary to control the first control valve 802, the second control valve 702, and the manual drain valve 501 to the closed state. At the same time, a first preset gas pressure threshold is set in the safety valve 401. The first gas pressure threshold is greater than the actual maximum operating pressure of the hydrogen fuel vehicle and less than the maximum gas pressure that each component in the hydrogen pipeline of the hydrogen fuel vehicle can withstand. For example, the first gas pressure threshold can be 105 MPa. Then, the airtightness test device 1 is connected to the working gas source 3 and the driving gas source 1. The working gas source 3 can be a nitrogen cylinder, and the driving gas source 4 can be compressed air or a nitrogen cylinder. Finally, the first control valve 802, the second control valve 702 and the gas booster pump 10 are opened in sequence, and the working gas source 3 enters the working gas source inlet 101 of the gas booster pump 10 through the second control valve 702, and the driving gas source 4 enters the driving gas source inlet 102 of the gas booster pump 10 through the first control valve 802. At the same time, the second pressure gauge 701 and the first pressure gauge 801 respectively monitor the gas pressures of the working gas source 3 and the driving gas source 4 in real time. Under the action of the driving gas source 4, the gas booster pump 10 pressurizes the working gas source 3.

[0107] S202, regulating the gas pressure output from the boosting pipeline to a second target output pressure using a pressure regulating valve, and turning off the gas boosting pump to maintain the pressure for a second preset time;

[0108] Specifically, refer to Figure 3When performing an airtightness test on the airtightness test device 1, it is necessary to ensure that the airtightness test device 1 can withstand the actual maximum operating pressure of the hydrogen pipeline of a hydrogen fuel vehicle and that there is no gas leakage at this operating pressure. The pressure regulating valve 201 is used to adjust the gas pressure output from the boost pipeline 20 to a second target output pressure, where the second target output pressure is the actual maximum operating pressure of the hydrogen pipeline of a hydrogen fuel vehicle. For example, the second target output pressure can be 70 MPa, and the first gas pressure threshold can be 1.5 times the second target output pressure. Observe the third pressure gauge 202. When the third pressure gauge 202 displays that the gas pressure is the second target output pressure, close the first control valve 802, the second control valve 702 and the gas booster pump 10 in sequence, and the manual control valve 501 remains in a closed state, thereby ensuring that the pressure of the pressurized gas in the airtightness test device 1 is stable, avoiding changes in gas pressure due to the circulation of gas in the device, and maintaining the second preset time in this pressure-maintaining state. For example, the second preset time is 30 minutes or longer, thereby improving the reliability of the test results.

[0109] S203: When a second pressure drop ratio of the gas pressure output from the boosting pipeline detected by the third pressure gauge within a second preset time is greater than or equal to a second preset pressure drop ratio threshold, determining that the air tightness of the test device does not meet the requirements;

[0110] Among them, the second pressure drop ratio is the ratio of the pressure difference between the second initial pressure and the second ending pressure to the second initial pressure, the second initial pressure is the gas pressure output by the boost pipeline at the initial moment of the second preset time, and the second ending pressure is the gas pressure output by the boost pipeline at the ending moment of the second preset time.

[0111] Specifically, the pressure difference between the initial and final moments of the second preset time period is calculated using the third pressure gauge 202. When the second pressure drop ratio is greater than or equal to a second preset pressure drop ratio threshold, the test device is determined to be unsatisfactory in terms of airtightness. For example, the second preset pressure drop ratio threshold may be 0.25%. It is understood that when the test device is unsatisfactory in terms of airtightness, it is also necessary to locate leaks throughout the test device, seal the leaks, and then retest the device for airtightness until the test device is found to meet the airtightness requirements.

[0112] The embodiment of the present invention ensures the reliability of the device by performing airtightness testing on the device. Applying the airtightness testing device to the airtightness testing of hydrogen pipelines in hydrogen fuel vehicles can more quickly locate gas leaks and improve detection efficiency.

[0113] Alternatively, as Figure 3 As shown, the hydrogen fuel vehicle hydrogen pipeline air tightness test device 1 further includes a safety pipeline 40, the air inlet of the safety pipeline 40 is connected to the boost pipeline 20, and the air outlet is connected to the outside;

[0114] A safety valve 401 is provided on the safety pipeline 40. The safety valve 401 is used to connect the boost pipeline 20 to the outside when the gas pressure in the boost pipeline 20 exceeds a first preset gas pressure threshold, and the first preset gas pressure threshold is adjustable.

[0115] Before conducting air tightness tests on the test device and vehicle pipelines, it is necessary to ensure that all components in the test device function normally and can meet the requirements of the air tightness test.

[0116] Furthermore, based on the hydrogen pipeline air tightness test device for hydrogen fuel vehicles of any of the above embodiments, the present invention also provides a test method for the air tightness detection phase of the hydrogen pipeline air tightness test device for hydrogen fuel vehicles, and the test method also includes a test device function detection phase, and the test device function detection phase is before the vehicle pipeline air tightness detection phase; specifically, it may include a third preparation phase and a third test phase, and the third preparation phase is before the third test phase.

[0117] The third preparation stage may include: closing the hydrogenation gun 30 and setting a first preset gas pressure threshold of the safety valve 401 .

[0118] Specifically, when performing a functional test on the airtightness test device 1, it is necessary to close the hydrogenation gun 30 to ensure that the airtightness test device 1 is disconnected from the vehicle hydrogenation port 2 to prevent the normal function of the vehicle pipeline from being affected by the uncertainty of the airtightness test device 1. A first preset gas pressure threshold is set for the safety valve 401. For example, the first preset gas pressure threshold can be 45 MPa.

[0119] Figure 6 This is a flow chart of the third test phase of the test device function detection phase in the hydrogen pipeline air tightness test method for a hydrogen fuel vehicle provided by an embodiment of the present invention, with reference to Figure 6 , the third testing phase may include:

[0120] S301, start the gas booster pump;

[0121] Specifically, refer to Figure 3Before starting the gas booster pump 10, it is necessary to control the first control valve 802, the second control valve 702, and the manual drain valve 501 to be closed. Then the air tightness test device 1 is connected to the working gas source 3 and the driving gas source 4, wherein the working gas source 3 can be a nitrogen bottle and the driving gas source 4 can be compressed air or a nitrogen bottle. Finally, the first control 802, the second control valve 702, and the gas booster pump 10 are opened in sequence. The working gas source 3 enters the working gas source inlet 101 of the gas booster pump 10 through the second control valve 702, and the driving gas source 4 enters the driving gas source inlet 102 of the gas booster pump 10 through the first control valve 802. At the same time, the second pressure gauge 701 and the first pressure gauge 801 respectively monitor the gas pressure of the working gas source 3 and the driving gas source 4 in real time. Under the action of the driving gas source 4, the gas booster pump 10 pressurizes the working gas source 3.

[0122] S302: Using a pressure regulating valve to adjust the gas pressure outputted by the boosting pipeline to exceed a first preset gas pressure threshold;

[0123] Specifically, the pressure regulating valve 201 is used to adjust the gas pressure output by the boost pipeline 20 and the gas pressure value in the boost pipeline 20 is observed through the third pressure gauge 202, so that the final gas pressure in the boost pipeline 20 exceeds the first preset gas pressure threshold. For example, the final gas pressure in the boost pipeline can be 50Mpa.

[0124] S303: When the gas pressure output from the boosting pipeline detected by the third pressure gauge is higher than a first preset gas pressure threshold, the safety valve releases pressure to determine that the safety valve functions normally.

[0125] Specifically, when the gas pressure output from the boosting pipeline 20, as detected by the third pressure gauge 202, exceeds a first preset gas pressure threshold, the safety valve 401 is observed to automatically open, thereby discharging excess gas in the boosting pipeline 20 through the outlet of the safety valve 401 to achieve the purpose of pressure relief. If the safety valve 401 automatically opens, it is determined that the safety valve 401 is functioning properly.

[0126] Optionally, the hydrogen pipeline air tightness test device 1 for hydrogen fuel vehicles also includes an exhaust pipeline 50, the air inlet of the exhaust pipeline 50 is connected to the boost pipeline 20, and the air outlet is connected to the outside; a manual exhaust valve 501 is provided on the exhaust pipeline 50, and the manual exhaust valve 501 is used to control the conduction or cutoff of the boost pipeline 20 with the outside.

[0127] Before starting the gas booster pump 10 to provide pressurized gas to the vehicle through the vehicle hydrogen filling port 30, after regulating the gas pressure output from the boosting pipeline 20 by the pressure regulating valve 201 to exceed the first preset gas pressure threshold, the method further includes:

[0128] S304, open the manual drain valve;

[0129] S305: When the gas pressure output from the boosting pipeline detected by the third pressure gauge drops below a second preset gas pressure threshold within a third preset time, it is determined that the manual drain valve functions normally.

[0130] Specifically, when the gas pressure output by the boost pipeline 20 exceeds the first preset gas pressure threshold, the safety valve 401 in the air tightness test device 1 automatically opens, thereby reducing the gas pressure output by the boost pipeline 20. After determining that the safety valve 401 is functioning normally, the air tightness test device 1 still contains gas, so the manual drain valve 501 can be opened to observe whether there is gas discharged from the outlet of the manual drain valve 501. At the same time, when the gas pressure output by the boost pipeline 20 detected by the third pressure gauge 202 drops to below the second preset gas pressure threshold within the third preset time, it is determined that the manual drain valve 501 is functioning normally.

[0131] After completing the functional test, the gas booster pump 10, the first control valve 802 and the second control valve 702 are closed in sequence, and the manual drain valve 501 is opened to exhaust all the gas in the air tightness test device.

[0132] This embodiment of the present invention determines the proper functioning of the safety valve by setting a first preset gas pressure threshold in the safety valve and, through a pressure-regulating valve, ensuring that the gas pressure output from the boost line exceeds the first preset gas pressure threshold. This is further confirmed by opening the manual drain valve and observing changes in gas pressure using a third pressure gauge. Prior to conducting airtightness tests on the airtightness test device and the hydrogen pipeline of a hydrogen fuel vehicle, the proper functioning of each component in the airtightness test device is ensured, thereby improving the reliability of the airtightness test device and ensuring safety during the testing process.

[0133] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A hydrogen fuel vehicle hydrogen pipeline air tightness test device, characterized in that: It comprises a gas booster pump and a booster pipeline, wherein the gas outlet of the gas booster pump is connected to the gas inlet of the booster pipeline; The gas outlet of the pressurized pipeline is provided with a hydrogenation gun, which is used to connect to the vehicle hydrogenation port and provide pressurized gas to the vehicle through the vehicle hydrogenation port; The boost pipeline is provided with a pressure regulating valve and a third pressure gauge in sequence from the air inlet to the air outlet; The pressure regulating valve is used to adjust the gas pressure output by the boost pipeline; The third pressure gauge is used to detect the pressure of the gas output by the boost pipeline.

2. The airtightness test device according to claim 1, characterized in that: It also includes a safety pipeline, the air inlet of the safety pipeline is connected to the boost pipeline, and the air outlet is connected to the outside; The safety pipeline is provided with a safety valve, and the safety valve is used to connect the boost pipeline to the outside when the gas pressure in the boost pipeline exceeds a first preset gas pressure threshold, and the first preset gas pressure threshold is adjustable.

3. The airtightness test device according to claim 2, characterized in that: It also includes an exhaust pipeline, wherein the air inlet of the exhaust pipeline is connected to the pressurization pipeline, and the air outlet is connected to the outside; The exhaust pipeline is provided with a manual exhaust valve, and the manual exhaust valve is used to control the communication or disconnection between the boost pipeline and the outside.

4. The airtightness test device according to claim 3, characterized in that: It also includes a four-way pipe connector, the four interfaces of which are respectively connected to the air outlet of the gas booster pump, the air inlet of the boosting pipeline, the air inlet of the safety pipeline and the air inlet of the exhaust pipeline.

5. The airtightness test device according to claim 1, characterized in that: It also includes a working gas source pipeline and a driving gas source pipeline; the air inlet of the working gas source pipeline is used to receive the working gas source, and the air outlet is connected to the working gas source air inlet of the gas booster pump; the air inlet of the driving gas source pipeline is used to receive the driving gas source, and the air outlet is connected to the driving gas source air inlet of the gas booster pump; The driving gas source pipeline is provided with a first pressure gauge and a first control valve in sequence from the air inlet to the air outlet; the first control valve is used to control the connection or cutoff between the driving gas source inlet of the gas booster pump and the driving gas source, and the first pressure gauge is used to detect the gas pressure in the driving gas source pipeline; The working gas source pipeline is provided with a second pressure gauge and a second control valve in sequence from the air inlet to the air outlet; the second control valve is used to control the connection or disconnection between the working gas source inlet of the gas booster pump and the working gas source, and the second pressure gauge is used to detect the gas pressure in the working gas source pipeline.

6. A method for testing the air tightness of hydrogen pipelines in hydrogen fuel vehicles, characterized in that: The method is carried out using the hydrogen pipeline air tightness test device for hydrogen fuel vehicles as described in any one of claims 1 to 5; The air tightness test method includes a vehicle pipeline air tightness detection stage; the vehicle hydrogen pipeline air tightness detection stage includes a first preparation stage and multiple first test stages, the first preparation stage is located before the first test stage; The first preparation stage includes: Connect the hydrogenation gun to the vehicle's hydrogenation port and turn on the hydrogenation gun; The first testing phase includes: activating the gas booster pump to provide pressurized gas to the vehicle through the vehicle hydrogen refueling port; Regulating the gas pressure output from the boosting pipeline to a first target output pressure using the pressure regulating valve, and turning off the gas boosting pump to maintain the pressure for a first preset time; When a first pressure drop ratio of the gas pressure output from the boost pipeline detected by the third pressure gauge within the first preset time is greater than or equal to a first preset pressure drop ratio threshold, determining that the air tightness of the vehicle hydrogen pipeline does not meet the requirement; Among them, the first pressure drop ratio is the ratio of the pressure difference between the first initial pressure and the first termination pressure to the first initial pressure, the first initial pressure is the gas pressure output by the boost pipeline at the initial moment of the first preset time, and the first termination pressure is the gas pressure output by the boost pipeline at the termination moment of the first preset time; the first target output pressure of each first test stage increases successively and has a preset pressure difference.

7. The airtightness test method according to claim 6, characterized in that: When a first pressure drop ratio of the gas pressure output from the boost pipeline detected by the third pressure gauge within the first preset time is greater than or equal to a first preset pressure drop ratio threshold, after determining that the air tightness of the vehicle hydrogen pipeline does not meet the requirement, the method further includes: Find the leak point; The leakage point is sealed, and the gas pressure output from the boosting pipeline of the pressure regulating valve is readjusted to the first target output pressure. The gas boosting pump is turned off and the pressure is maintained for a first preset time until the first pressure drop ratio of the gas pressure output from the boosting pipeline detected by the third pressure gauge within the first preset time is less than the first preset pressure drop ratio threshold.

8. The airtightness test method according to claim 6, characterized in that: The air tightness test method further includes a test device air tightness test stage; the test device air tightness test stage is before the vehicle pipeline air tightness test stage; The airtightness detection phase of the test device includes a second preparation phase and a second test phase, wherein the second preparation phase is located before the second test phase; The second preparation stage includes: Close the hydrogenation gun; The second testing phase includes: Starting the gas booster pump; Regulating the gas pressure output from the boosting pipeline to a second target output pressure using the pressure regulating valve, and turning off the gas boosting pump to maintain the pressure for a second preset time; When a second pressure drop ratio of the gas pressure output from the boosting pipeline detected by the third pressure gauge within the second preset time is greater than or equal to a second preset pressure drop ratio threshold, determining that the air tightness of the test device does not meet the requirement; Among them, the second pressure drop ratio is the ratio of the pressure difference between the second initial pressure and the second ending pressure to the second initial pressure, the second initial pressure is the gas pressure output by the boost pipeline at the initial moment of the second preset time, and the second ending pressure is the gas pressure output by the boost pipeline at the ending moment of the second preset time.

9. The airtightness test method according to claim 6, characterized in that: The hydrogen fuel vehicle hydrogen pipeline air tightness test device further includes a safety pipeline, the air inlet of the safety pipeline is connected to the boost pipeline, and the air outlet is connected to the outside; The safety pipeline is provided with a safety valve, and the safety valve is used to connect the boosting pipeline to the outside when the gas pressure in the boosting pipeline exceeds a first preset gas pressure threshold, and the first preset gas pressure threshold is adjustable; The air tightness test method further includes a test device function test stage; the test device function test stage is before the vehicle pipeline air tightness test stage; The functional detection phase of the test device includes a third preparation phase and a third test phase, wherein the third preparation phase is located before the third test phase; The third preparation stage includes: Close the hydrogenation gun; Setting a first preset gas pressure threshold of the safety valve; The third testing phase includes: Starting the gas booster pump; Utilizing the pressure regulating valve to adjust the gas pressure outputted by the boosting pipeline to exceed the first preset gas pressure threshold; When the gas pressure output from the boost pipeline detected by the third pressure gauge is higher than the first preset gas pressure threshold, the safety valve releases pressure to determine that the safety valve functions normally.

10. The airtightness test method according to claim 9, characterized in that: The hydrogen fuel vehicle hydrogen pipeline air tightness test device further includes an exhaust pipeline, the air inlet of the exhaust pipeline is connected to the boost pipeline, and the air outlet is connected to the outside; A manual drain valve is provided on the drain pipeline, and the manual drain valve is used to control the connection or disconnection between the boost pipeline and the outside; Before starting the gas booster pump to provide pressurized gas to the vehicle through the vehicle hydrogen refueling port, after using the pressure regulating valve to adjust the gas pressure output from the boost pipeline to exceed the first preset gas pressure threshold, the method further includes: Open the manual drain valve; When the gas pressure output from the boost pipeline detected by the third pressure gauge drops below a second preset gas pressure threshold within a third preset time, it is determined that the manual drain valve functions normally.

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