Air tightness testing apparatus

Abstract

The utility model provides a kind of air-tightness testing device, including first gas path unit, second gas path unit and third gas path unit, first gas path unit includes first gas pipeline, and high-pressure gas source, first needle valve, high-pressure pressure gauge and three-way ball valve being arranged at first gas pipeline, the first output end of first gas pipeline is used to connect measured piece;Second gas path unit includes second gas pipeline, and low-pressure gas source and second needle valve being arranged at second gas pipeline, and the second output end of second gas pipeline is communicated with first gas pipeline;Third gas path unit includes third gas pipeline, and first ball valve, pressure reducing valve, second ball valve and low-pressure pressure gauge being arranged at third gas pipeline, and the third input end of third gas pipeline is communicated with second gas pipeline, and the third output end of third gas pipeline is used to connect measured piece.The application is high in integration, and different pressure air-tightness test can be carried out according to requirement.

Description

Technical Field

[0001] This utility model relates to the field of airtightness testing technology, and in particular to an airtightness testing device. Background Technology

[0002] Air tightness testing is a crucial step in industrial production and product inspection, widely used for quality control and performance verification of components such as solenoid valves, gas-liquid separators, ejectors, and hydrogen circulation pumps. For example, in fuel cell systems, the hydrogen supply module, as the core component for hydrogen delivery and regulation, directly affects the system's safety, stability, and energy efficiency. Hydrogen is a flammable and explosive gas; even a small leak can trigger explosions and fires, while also reducing fuel cell stack reaction efficiency and increasing energy consumption. Therefore, high-precision, high-reliability air tightness testing of the hydrogen supply module is a critical aspect of manufacturing and quality control.

[0003] The airtightness of solenoid valves, gas-liquid separators, ejectors, and hydrogen circulation pumps directly affects the safety and reliability of the hydrogen supply module. Therefore, high-pressure and low-pressure airtightness tests are required for solenoid valves, and low-pressure airtightness tests are required for gas-liquid separators, ejectors, and hydrogen circulation pumps. Currently, existing airtightness testing devices typically employ a single gas path structure, adjusting the gas source output pressure to adapt to different testing requirements. However, this approach has several limitations: First, frequent adjustments to the gas source pressure are not only cumbersome and inefficient but also prone to introducing human error, affecting the accuracy and consistency of test results. Second, existing devices often lack flexible flow path control mechanisms, making it impossible to quickly switch between different testing modes, resulting in poor test adaptability. This is especially true when the types of test components are diverse, requiring replacement or adjustment of test fixtures, increasing time and costs. Furthermore, some improved testing devices attempt to expand functionality by adding multiple gas sources or complex valves, but these often suffer from low integration, complex operation, and an inability to achieve multi-pressure level testing under a fixed gas source pressure. Utility Model Content

[0004] The purpose of this invention is to provide an airtightness testing device with high integration, which can perform airtightness tests at different pressures as needed.

[0005] To achieve the above objectives, the airtightness testing device of this utility model includes a first air path unit, a second air path unit, and a third air path unit. The first air path unit includes a first air supply pipeline, a high-pressure gas source, a first needle valve, a high-pressure gauge, and a three-way ball valve. The first input end of the first air supply pipeline is connected to the high-pressure gas source, and the first output end of the first air supply pipeline is used to connect to the test piece. The first needle valve, the high-pressure gauge, and the three-way ball valve are sequentially arranged in the first air supply pipeline along the gas delivery direction. The second air path unit includes a low-pressure gas source, a second air supply pipeline, and a second needle valve. The second input end of the second air supply pipeline is connected to the test piece. The low-pressure gas source is described above. The second output end of the second gas supply line is connected to the first gas supply line between the high-pressure gauge and the three-way ball valve. The second needle valve is disposed in the second gas supply line. The third gas circuit unit includes a third gas supply line, a first ball valve, a pressure reducing valve, a second ball valve, and a low-pressure gauge. The third input end of the third gas supply line is connected to the second gas supply line between the low-pressure gas source and the second needle valve. The third output end of the third gas supply line is used to connect to the device under test. The first ball valve, the pressure reducing valve, the second ball valve, and the low-pressure gauge are sequentially disposed in the third gas supply line along the gas delivery direction within the third gas supply line.

[0006] Preferably, the second gas circuit unit further includes a one-way valve, which is disposed in the second gas supply line between the second needle valve and the second output end of the second gas supply line.

[0007] Preferably, the first gas path unit further includes a first safety relief valve, which is disposed in the first gas supply line between the high-pressure gas source and the first needle valve; the second gas path unit further includes a second safety relief valve, which is disposed in the second gas supply line between the low-pressure gas source and the second needle valve; the third gas path unit further includes a third safety relief valve, which is disposed in the third gas supply line between the low-pressure gauge and the third output terminal, or the third safety relief valve is disposed in the connecting line between the third output terminal and the input terminal of the device under test.

[0008] Preferably, the airtightness testing device further includes an exhaust gas treatment device, wherein the first safety relief valve, the pressure relief output end of the three-way ball valve, the second safety relief valve, and the third safety relief valve are all connected to the exhaust gas treatment device.

[0009] Preferably, the first gas circuit unit further includes a first throttle valve, which is disposed in the first gas supply pipeline between the high-pressure gas source and the first safety relief valve; the second gas circuit unit further includes a second throttle valve, which is disposed in the second gas supply pipeline between the low-pressure gas source and the second safety relief valve.

[0010] Preferably, the first preset pressure relief value of the first safety relief valve is greater than the first target pressure value of the gas output from the high-pressure gas source; the second preset pressure relief value of the second safety relief valve is greater than the second target pressure value of the gas output from the low-pressure gas source; and the third preset pressure relief value of the three safety relief valves is greater than the third target pressure value preset by the pressure reducing valve.

[0011] Preferably, the first target pressure value is greater than the second target pressure value, and the second target pressure value is greater than the third target pressure value; the first preset pressure relief value is greater than the second preset pressure relief value, and the second preset pressure relief value is greater than the third preset pressure relief value.

[0012] Preferably, the device under test includes a hydrogen supply module, which includes a solenoid valve, a vapor-water separator, an ejector, and a hydrogen circulation pump. The first output end of the first gas supply pipeline is used to connect to the input end of the solenoid valve, and the third output end of the third gas supply pipeline is used to connect to the output end of the solenoid valve, the input end of the vapor-water separator, the input end of the ejector, or the input end of the hydrogen circulation pump.

[0013] Preferably, the first target pressure value is greater than 8 barg and less than 20 barg; the second target pressure value is greater than 0 barg and less than or equal to 8 barg; and the third target pressure value is greater than 0 barg and less than or equal to 3 barg.

[0014] Preferably, the airtightness testing device further includes a handheld concentration detector, the first output end of the first gas supply line is used to connect to the input end of the test object, and the third output end of the third gas supply line is used to connect to the output end of the test object.

[0015] The beneficial effects of the airtightness testing device of this utility model are as follows: (1) In this application, by setting a first needle valve, a second needle valve, a first ball valve and a second ball valve, the first needle valve can be opened or closed to connect or disconnect the corresponding first gas supply line, the second needle valve can be opened or closed to connect or disconnect the corresponding second gas supply line, and the first ball valve can be opened or closed to connect or disconnect the corresponding third gas supply line, thereby realizing different air tightness test requirements; for example, the first ball valve is closed when the third gas supply unit is not used for air tightness test; and when the first output terminal is connected to the test piece, and high pressure air tightness test and low pressure air tightness test are performed through the first gas supply unit and the second gas supply unit, the first ball valve and the second ball valve need to be closed in order to detect whether the test piece, such as the solenoid valve, has internal leakage.

[0016] (2) By setting up high pressure gauges and low pressure gauges, precise pressure monitoring can be carried out for different pressure density tests, ensuring the reliability and accuracy of the test results.

[0017] (3) By setting a three-way ball valve, the pressure can be released quickly when the test ends, and the test piece can be replaced, which is beneficial to improve safety performance and test efficiency.

[0018] (4) By setting a pressure reducing valve in the third gas supply line, the low-pressure gas source can output gas at the same pressure, so that the third gas supply unit can perform a gas tightness test at a different pressure than the second gas supply unit.

[0019] (5) In this application, by setting the high-pressure gas source and the low-pressure gas source, not only can the airtightness test requirements at different pressures be achieved by adjusting the pressure value of the gas output from the high-pressure gas source (setting different first target pressures) and the pressure value of the gas output from the low-pressure gas source (setting different second target pressures), but also by fixing the pressure value of the gas output from the high-pressure gas source (i.e., keeping the set first target pressure unchanged) and the pressure value of the gas output from the low-pressure gas source (i.e., keeping the set second target pressure unchanged), and then by connecting the high-pressure gas source to the first gas supply pipeline, so that the test device is connected at the first output end, and the high-pressure gas source outputs high-pressure gas, the high-pressure airtightness of the test device can be tested, or the low-pressure gas source is connected to the third gas supply pipeline, so that the test device is connected at the third output end, and the low-pressure gas source outputs low-pressure gas and passes through After the pressure is reduced by the pressure reducing valve, the low-pressure airtightness of the test piece can be tested, and the low-pressure gas source can be connected to the second gas supply pipeline. This allows the test piece to be connected to the first output end, where the low-pressure gas source outputs low-pressure gas, which is then transported to the first output end via the second gas supply pipeline. Since the gas flowing through the third gas supply pipeline is depressurized by the pressure reducing valve, the pressure of the gas transported to the first output end via the second gas supply pipeline will be relatively higher. This achieves the testing of the airtightness of the test piece in a medium-pressure environment (relative to the test pressures of the first and third gas supply units). This application allows for fixing the pressure values ​​of the output gas from the high-pressure and low-pressure gas sources, i.e., achieving multi-pressure level testing under a fixed gas source pressure. This fulfills the airtightness testing requirements at different pressures and avoids frequent adjustments to the output gas pressure values ​​of the high-pressure and low-pressure gas sources, which is beneficial for improving testing efficiency and ensuring testing accuracy.

[0020] (6) This application has a high degree of integration and can perform air tightness tests at different pressures according to requirements. Moreover, it is easy to operate. Just install and fix the tooling and open the corresponding pipeline pressure to complete the test.

[0021] (7) It has strong applicability and a wide range of pressure testing capabilities. It can test the air tightness of different test components, such as the high-pressure air tightness test and low-pressure air tightness test of the solenoid valve in the hydrogen supply module, the low-pressure air tightness test of the gas-water separator, ejector, and hydrogen circulation pump in the hydrogen supply module, as well as the high-pressure air tightness test and low-pressure air tightness test of the solenoid valve in other devices, and the air tightness test of components in other devices, etc. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structural connection of the airtightness testing device according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1. First gas circuit unit; 10. First gas supply line; 11. High-pressure gas source; 12. First throttle valve; 13. First safety relief valve; 14. First needle valve; 15. High-pressure gauge; 16. Three-way ball valve; 161. Pressure relief output end; 17. First output end; 2. Second gas circuit unit; 20. Second gas supply line; 21. Low-pressure gas source; 22. Second throttle valve; 23. Second safety relief valve; 24. Second needle valve; 25. Check valve; 26. Second output end; 3. Third gas circuit unit; 30. Third gas supply line; 31. First ball valve; 32. Pressure reducing valve; 33. Second ball valve; 34. Low-pressure gauge; 35. Third input end; 36. Third output end; 37. Third safety relief valve; 38. Connecting pipeline. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0025] To overcome the problems existing in the prior art, this utility model provides an airtightness testing device with high integration, which can perform airtightness tests at different pressures as needed.

[0026] In some embodiments of this utility model, reference is made to Figure 1The airtightness testing device includes a first air circuit unit 1, a second air circuit unit 2, and a third air circuit unit 3. The first air circuit unit 1 includes a first gas supply line 10, a high-pressure gas source 11, a first needle valve 14, a high-pressure gauge 15, and a three-way ball valve 16. The first input end of the first gas supply line 10 is connected to the high-pressure gas source 11, and the first output end 17 of the first gas supply line 10 is used to connect to the device under test. The first needle valve 14, the high-pressure gauge 15, and the three-way ball valve 16 are sequentially arranged in the first gas supply line 10 along the gas delivery direction within the first gas supply line 10. The second air circuit unit 2 includes a low-pressure gas source 21, a second gas supply line 20, and a second needle valve 24. The second input end of the second gas supply line 20 is connected to the low-pressure gas source 21, and the second output end 26 of the second gas supply line 20 is connected to the high-pressure gas source 21. The first gas supply line 10 between the pressure gauge 15 and the three-way ball valve 16 is connected, and the second needle valve 24 is disposed in the second gas supply line 20; the third gas supply unit 3 includes a third gas supply line 30, a first ball valve 31, a pressure reducing valve 32, a second ball valve 33 and a low-pressure gauge 34, the third input end 35 of the third gas supply line 30 is connected to the second gas supply line 20 between the low-pressure gas source 21 and the second needle valve 24, and the third output end 36 of the third gas supply line 30 is used to connect to the test piece, and the first ball valve 31, the pressure reducing valve 32, the second ball valve 33 and the low-pressure gauge 34 are sequentially disposed in the third gas supply line 30 along the gas delivery direction in the third gas supply line 30.

[0027] In this embodiment, when it is necessary to test the airtightness of the test piece in a high-pressure environment (i.e., high-pressure airtightness), the test piece is connected to the first output terminal 17 of the first gas supply pipeline 10. The output gas pressure of the high-pressure gas source 11 is set as the first target pressure. The high-pressure gas source 11, the first needle valve 14, and the three-way ball valve 16 are opened to supply high-pressure gas to the test piece connected to the first output terminal 17 through the first gas supply pipeline 10 until the pressure value displayed by the high-pressure pressure gauge 15 reaches the first target pressure. Then, the first needle valve 14 is closed, and it is observed whether the pressure value displayed by the high-pressure pressure gauge 15 decreases. If the pressure value displayed by the high-pressure pressure gauge 15 maintains the first target pressure within a standard time, or the pressure value of the test piece decreases, the test piece is considered airtight. If the pressure drop value displayed by the high-pressure gauge 15 within the standard time does not exceed the standard pressure value, it indicates that the tested component has passed the high-pressure airtightness test. If the pressure drop value displayed by the high-pressure gauge 15 within the standard time exceeds the standard pressure value, it indicates that the tested component has internal or external leakage. In this case, the pressure drop value displayed by the high-pressure gauge 15 within the standard time exceeding the standard pressure value may also be due to external leakage in components of the first air circuit unit 1, such as the first air supply pipeline 10. However, the airtightness testing device is generally checked for leakage before testing to reduce the workload when conducting subsequent airtightness tests on the tested component. If internal or external leakage of the tested component is ruled out, the airtightness testing device can be tested.

[0028] In the embodiments of this utility model, internal leakage refers to the fluid (here, gas) still flowing from the inlet (P) to the outlet (A or B) through the internal channels of the test device when it should be completely shut off (power off state). In other words, the medium has leaked unnecessarily between the internal channels of the test device. External leakage refers to the gas leaking from the inside of the test device into the external environment, which not only wastes energy but also poses a serious safety hazard in toxic, flammable, and explosive gas environments.

[0029] In this embodiment, when it is necessary to test the airtightness of the test piece in a low-pressure environment (i.e., low-pressure airtightness), and when the operating low-pressure pressure of the test piece is relatively high (i.e., medium pressure relative to high and low pressure), the test piece can be connected to the first output terminal 17 of the first gas supply line 10. The output gas pressure of the low-pressure gas source 21 is set as the second target pressure. The low-pressure gas source 21, the second needle valve 24, and the three-way ball valve 16 are opened, and the first needle valve 14 is closed. Low-pressure gas is then supplied to the test piece connected to the first output terminal 17 through the second gas supply line 20 until the pressure value displayed by the high-pressure gauge 15 reaches the second target pressure. Close the second needle valve 24, and then observe whether the pressure value displayed by the high-pressure gauge 15 decreases. If the pressure value displayed by the high-pressure gauge 15 maintains the second target pressure within the standard time, or if the pressure value decreased by the high-pressure gauge 15 within the standard time does not exceed the standard pressure value, it indicates that the tested component has passed the low-pressure airtightness test. If the pressure value decreased by the high-pressure gauge 15 within the standard time exceeds the standard pressure value, it indicates that the tested component has internal or external leakage, or even leakage in the components of the second air circuit unit 2, the first air supply pipeline 10 between the first needle valve 14 and the first output terminal 17, and the components installed on it.

[0030] In this embodiment, when it is necessary to test the airtightness of the test piece in a low-pressure environment (i.e., low-pressure airtightness), and when the operating low-pressure pressure of the test piece is relatively low, the test piece can be connected to the third output terminal 36 of the third gas supply line 30. The output gas pressure of the low-pressure gas source 21 is set as the second target pressure, the pressure of the pressure reducing valve 32 is set as the third target pressure, and the low-pressure gas source 21, the first ball valve 31, the pressure reducing valve 32, and the second ball valve 33 are opened to supply low-pressure gas to the test piece connected to the third output terminal 36 through the second gas supply line 20 between the low-pressure gas source 21 and the third input terminal 35, and the third gas supply line 30. (At this time, the second needle valve 24 can be closed to perform low-pressure airtightness testing solely through the third gas circuit unit 3, or simultaneously through the first gas circuit unit 1 to perform high-pressure airtightness testing; alternatively, the second needle valve 24 can be opened to supply low-pressure gas to the test piece connected to the third output terminal 36 through the second gas supply line 20 between the low-pressure gas source 21 and the third input terminal 35.) The gas supply line 20 supplies low-pressure gas to the test piece connected to the first output terminal 17 (i.e., low-pressure airtightness testing is performed simultaneously through the second gas supply unit 2 and the third gas supply unit 3 at different pressures) until the pressure value displayed by the low-pressure gauge 34 reaches the third target pressure. Then, the second ball valve 33 is closed, and the pressure value displayed by the low-pressure gauge 34 is observed to see if it decreases. If the pressure value displayed by the low-pressure gauge 34 maintains the third target pressure within a standard time, or if the pressure decrease displayed by the low-pressure gauge 34 within a standard time does not exceed the standard pressure value, it indicates that the test piece has passed the low-pressure airtightness test. If the pressure decrease displayed by the low-pressure gauge 34 within a standard time exceeds the standard pressure value, it indicates that the test piece has a leak, or even that the second gas supply line 20 between the low-pressure gas source 21 and the third input terminal 35, its components, and the third gas supply unit 3 have a leak.

[0031] In embodiments of this utility model, the standard time and the standard pressure value are set according to the requirements of the test piece or various test standards. For example, if the pressure value displayed by the high-pressure gauge 15 (or the low-pressure gauge 34) decreases by no more than 0.015 barg within 3 minutes, and the hydrogen concentration around the test piece does not exceed 5 ppm within 3 minutes, then the test piece has passed the high-pressure airtightness test (or low-pressure airtightness test). If the pressure value displayed by the high-pressure gauge 15 (or the low-pressure gauge 34) decreases by more than the standard pressure value within the standard time, then the test piece has failed the high-pressure airtightness test (or low-pressure airtightness test).

[0032] In this application, the first needle valve 14, the second needle valve 24, the first ball valve 31, and the second ball valve 33 are on / off valves. They can be opened or closed according to testing needs to connect or disconnect the corresponding first gas supply line 10, the second needle valve 24 to connect or disconnect the corresponding second gas supply line 20, and the first ball valve 31 to connect or disconnect the corresponding third gas supply line 30, thereby achieving different airtightness testing requirements. For example, when the third gas supply unit 3 is not used for airtightness testing, the first ball valve 31 is closed; while when the first output terminal 17 is connected to the device under test, the first gas supply line... When performing high-pressure and low-pressure airtightness tests on Unit 1 and the second gas circuit unit 2, the first ball valve 31 and the second ball valve 33 must be closed to detect whether the tested component, such as the solenoid valve, has internal leakage (at this time, the input and output ends of the solenoid valve are connected to the first output end 17 and the third output end 36, respectively, as described in detail in subsequent embodiments). By setting the high-pressure gauge 15 and the low-pressure gauge 34, precise pressure monitoring can be performed for different pressure density tests, ensuring the reliability and accuracy of the test results. By setting the three-way ball valve 16, pressure can be quickly released at the end of the test, allowing for replacement of the test component, which is beneficial for improving safety performance and testing efficiency. By setting the pressure reducing valve 32 in the third gas supply line 30, the low-pressure gas source 21 can output gas at the same pressure, enabling the third gas circuit unit 3 to perform airtightness tests at different pressures than the second gas circuit unit 2.In this application, by setting the high-pressure gas source 11 and the low-pressure gas source 21, not only can the airtightness testing requirements at different pressures be achieved by adjusting the pressure value of the gas output from the high-pressure gas source 11 (setting different first target pressures) and the pressure value of the gas output from the low-pressure gas source 21 (setting different second target pressures), but also by fixing the pressure value of the gas output from the high-pressure gas source 11 (i.e., keeping the set first target pressure unchanged) and the pressure value of the gas output from the low-pressure gas source 21 (i.e., keeping the set second target pressure unchanged), and by connecting the high-pressure gas source 11 to the first gas supply pipeline 10, so that the test device is connected at the first output end 17, the high-pressure gas source 11 can test the high-pressure airtightness of the test device when it outputs high-pressure gas, or by connecting the low-pressure gas source 21 to the third gas supply pipeline 30, so that the test device is connected at the third output end 36, the low-pressure gas source 21 outputs low-pressure gas and passes through After the pressure reducing valve 32 reduces the pressure, it can test the low-pressure airtightness of the test piece and connect the low-pressure gas source 21 to the second gas supply line 20. This allows the test piece to be connected to the first output end 17. The low-pressure gas source 21 outputs low-pressure gas, which is then transported to the first output end 17 via the second gas supply line 20. The gas flowing through the third gas supply line 30 is reduced in pressure by the pressure reducing valve 32, resulting in a relatively higher pressure for the gas supplied to the first output end 17 via the second gas supply line 20. This enables the test of the airtightness of the test piece in a medium-pressure environment (relative to the test pressures of the first gas supply unit 1 and the third gas supply unit 3). This allows the application to fix the pressure values ​​of the output gas in the high-pressure gas source 11 and the low-pressure gas source 21, i.e., to achieve multi-pressure level testing under a fixed gas source pressure. This fulfills the airtightness testing requirements at different pressures and avoids frequent adjustments to the pressure values ​​of the output gas in the high-pressure gas source 11 and the low-pressure gas source 21, which is beneficial for improving testing efficiency and ensuring testing accuracy.

[0033] This application boasts high integration, enabling airtightness testing at varying pressures as required. It is also simple to operate; simply install and secure the fixture, open the corresponding pipeline pressure, and the test is complete. It is highly adaptable, with a wide pressure testing range, capable of testing the airtightness of various components, such as high-pressure and low-pressure airtightness tests of solenoid valves in hydrogen supply modules, low-pressure airtightness tests of gas-liquid separators, ejectors, and hydrogen circulation pumps in hydrogen supply modules, as well as high-pressure and low-pressure airtightness tests of solenoid valves in other devices, and airtightness tests of components in other devices.

[0034] In some embodiments of this utility model, the airtightness testing device further includes a handheld concentration detector, the first output end 17 of the first gas supply line 10 is used to connect to the input end of the test piece, and the third output end 36 of the third gas supply line 30 is used to connect to the output end of the test piece, so that it is possible to detect whether the test piece has internal or external leakage.

[0035] In this embodiment, the input end of the device under test (DUT) can be connected to the first output end 17 of the first gas supply line 10, and the output end of the DUT can be connected to the third output end 36 of the third gas supply line 30. The second ball valve 33 is then closed. When high-pressure gas is supplied to the DUT connected to the first output end 17 via the first gas supply line 10, and low-pressure gas is supplied to the DUT connected to the first output end 17 via the second gas supply line 20, the pressure value displayed by the high-pressure gauge 15 decreases. It is then possible to observe whether the pressure value displayed by the low-pressure gauge 34 changes. If it changes, it indicates that the DUT has experienced internal leakage. If it does not change, a handheld concentration detector can be used to detect the gas concentration in the air near the DUT to determine whether external leakage has occurred. In other words, this application enables the detection of both internal and external leaks in DUTs with internal channels by flexibly opening or closing the components in the first gas supply unit 1, the second gas supply unit 2, and the third gas supply unit 3.

[0036] In other embodiments of this invention, soapy water or a professional leak detection solution can be applied to the surface of the tested component or gas pipeline, including various interfaces, end caps, and coil roots, to observe whether bubbles are generated, thereby determining which component is leaking.

[0037] In some embodiments of this utility model, reference is made to Figure 1 The first gas circuit unit 1 also includes a first safety relief valve 13. The first safety relief valve 13 is disposed in the first gas supply pipeline 10 between the high-pressure gas source 11 and the first needle valve 14. The gas circuit is equipped with overpressure protection, so that when the pressure is abnormal, the first safety relief valve 13 can automatically and quickly relieve the pressure of the first gas supply pipeline 10. It has strong safety and avoids damage to the components in the first gas circuit unit 1 due to excessive gas pressure in the first gas supply pipeline 10, or accidental accidents such as leakage in the first gas supply pipeline 10.

[0038] In some embodiments of this utility model, reference is made to Figure 1The second gas circuit unit 2 also includes a second safety relief valve 23. The second safety relief valve 23 is disposed in the second gas supply line 20 between the low-pressure gas source 21 and the second needle valve 24. The gas circuit is equipped with overpressure protection, so that the second gas supply line 20 can be quickly depressurized through the second safety relief valve 23 when the pressure is abnormal. It has strong safety and avoids damage to the components in the second gas circuit unit 2 due to excessive gas pressure in the second gas supply line 20, or accidental accidents such as leakage in the second gas supply line 20.

[0039] In some embodiments of this utility model, reference is made to Figure 1 The third gas circuit unit 3 further includes a third safety relief valve 37. The third safety relief valve 37 is disposed in the third gas supply pipeline 30 between the low pressure gauge 34 and the third output terminal 36, or the third safety relief valve 37 is disposed in the connecting pipeline 38 between the third output terminal 36 and the input terminal of the device under test. The gas circuit is equipped with overpressure protection, so that when the pressure is abnormal, the third safety relief valve 37 can automatically and quickly relieve the pressure of the third gas supply pipeline 30. The safety is strong, and it avoids the gas pressure in the third gas supply pipeline 30 from being too high and damaging the components in the third gas circuit unit 3, or causing accidents such as leakage in the third gas supply pipeline 30.

[0040] In some embodiments of this utility model, the airtightness testing device further includes an exhaust gas treatment device. The first safety pressure relief valve 13, the pressure relief output terminal 161 of the three-way ball valve 16, the second safety pressure relief valve 23, and the third safety pressure relief valve 37 are all connected to the exhaust gas treatment device to prevent the gas in the first gas supply line 10, the second gas supply line 20, and the third gas supply line 30 from being directly discharged into the atmosphere during pressure relief, which is beneficial to environmental protection and avoids dangerous accidents. The pressure relief output terminal 161 of the three-way ball valve 16 is connected to the exhaust gas treatment device so that after the test is completed, the test gas in the first gas supply line 10 and the second gas supply line 20 is discharged through the pressure relief output terminal 161 of the three-way ball valve 16.

[0041] In some embodiments of this utility model, reference is made to Figure 1 The first gas circuit unit 1 further includes a first throttle valve 12, which is disposed in the first gas supply pipeline 10 between the high-pressure gas source 11 and the first safety relief valve 13. This allows the flow rate of the gas supplied in the first gas supply pipeline 10 to be adjusted by the first throttle valve 12, preventing the gas flow rate in the first gas supply pipeline 10 from being too large. This avoids the failure of the components in the first gas circuit unit 1 due to the first safety relief valve 13 not releasing pressure in time, or the leakage of the first gas supply pipeline 10 and other accidents, which is beneficial to protecting the airtightness testing device.

[0042] In some embodiments of this utility model, reference is made to Figure 1 The second gas circuit unit 2 also includes a second throttle valve 22, which is disposed in the second gas supply pipeline 20 between the low-pressure gas source 21 and the second safety relief valve 23. This allows the flow rate of the gas supplied in the second gas supply pipeline 20 to be adjusted through the second throttle valve 22, preventing excessive gas flow in the second gas supply pipeline 20. This avoids malfunctions of components in the second gas circuit unit 2 and the third gas circuit unit 3 due to untimely pressure relief by the second safety relief valve 23 and the third safety relief valve 37, or leaks in the second gas supply pipeline 20 and the third gas supply pipeline 30, thus protecting the airtightness testing device.

[0043] In some embodiments of this utility model, reference is made to Figure 1 The second gas circuit unit 2 also includes a one-way valve 25. The one-way valve 25 is disposed in the second gas supply line 20 between the second needle valve 24 and the second output end 26 of the second gas supply line 20. Due to the characteristics of the one-way valve 25, gas can only flow from the second gas supply line 20 through the one-way valve 25 to the first gas supply line 10. This effectively prevents high-pressure gas from entering the second gas supply line 20 and the third gas supply line 30 from the second output end 26 when the test piece is connected to the first output end 17 for high-pressure airtightness testing. This avoids damage to the components in the second gas circuit unit 2 and the third gas circuit unit 3, as well as the test piece connected to the third output end 36, caused by high-pressure gas.

[0044] In some embodiments of this utility model, the first preset pressure relief value of the first safety relief valve 13 is greater than the first target pressure value of the gas output by the high-pressure gas source 11, so as to ensure that the first gas circuit unit 1 can work normally and avoid frequent pressure relief of the first gas transmission pipeline 10.

[0045] In some embodiments of this utility model, the second preset pressure relief value of the second safety relief valve 23 is greater than the second target pressure value of the gas output from the low-pressure gas source 21, so as to ensure that the second gas circuit unit 2 can work normally and avoid frequent pressure relief of the second gas transmission pipeline 20.

[0046] In some embodiments of this utility model, the third preset pressure relief value of the three safety relief valve is greater than the third preset target pressure value of the pressure reducing valve 32, so as to ensure that the third gas circuit unit 3 can work normally and avoid frequent pressure relief of the third gas transmission pipeline 30.

[0047] In some embodiments of this utility model, the first target pressure value is greater than the second target pressure value, and the second target pressure value is greater than the third target pressure value. This is beneficial for conducting airtightness tests according to different pressure requirements, enabling high-pressure airtightness tests, medium-pressure airtightness tests, and low-pressure airtightness tests to be performed on the test piece.

[0048] In some embodiments of this utility model, the first preset pressure relief value is greater than the second preset pressure relief value, and the second preset pressure relief value is greater than the third preset pressure relief value.

[0049] In some embodiments of this utility model, the tested component includes a hydrogen supply module, which includes a solenoid valve, a vapor-liquid separator, an ejector, and a hydrogen circulation pump. The first output terminal 17 of the first gas supply pipeline 10 is used to connect to the input terminal of the solenoid valve, and the third output terminal 36 of the third gas supply pipeline 30 is used to connect to the output terminal of the solenoid valve, the input terminal of the vapor-liquid separator, the input terminal of the ejector, or the input terminal of the hydrogen circulation pump. This application can perform airtightness tests at different pressures as needed, that is, it integrates multi-functional airtightness testing, enabling simultaneous high-pressure and low-pressure airtightness tests on the solenoid valve in the hydrogen supply module, as well as low-pressure airtightness tests on the vapor-liquid separator, ejector, and hydrogen circulation pump in the hydrogen supply module. This avoids the need to replace airtightness testing equipment, improves testing efficiency, and saves costs.

[0050] Because the solenoid valve in the hydrogen supply module operates at a high pressure not exceeding 20 barg and a low pressure not exceeding 8 barg, and the vapor-water separator, ejector, and hydrogen circulation pump in the hydrogen supply module operate at a pressure not exceeding 3 barg, in some embodiments of this utility model, the first target pressure value is greater than 8 barg and less than 20 barg; the second target pressure value is greater than 0 barg and less than or equal to 8 barg; and the third target pressure value is greater than 0 barg and less than or equal to 3 barg. This ensures that the high-pressure and low-pressure airtightness tests of the solenoid valve in the hydrogen supply module, as well as the low-pressure airtightness tests of the vapor-water separator, ejector, and hydrogen circulation pump in the hydrogen supply module, are met.

[0051] In some specific embodiments of this utility model, reference is made to Figure 1When it is necessary to test the airtightness of the solenoid valve of the hydrogen supply module in a high-pressure environment, i.e., high-pressure airtightness, the input terminal of the solenoid valve of the hydrogen supply module is connected to the first output terminal 17 of the first gas supply pipeline 10, and the output terminal of the solenoid valve of the hydrogen supply module is connected to the third output terminal 36 of the third gas supply pipeline 30. Based on the high-pressure value used by the solenoid valve, a first target pressure value is set for the output gas pressure of the high-pressure gas source 11, and a first preset pressure relief value is set for the first safety relief valve 13. Then, the high-pressure gas source 11, the first throttle valve 12, the first needle valve 14, and the three-way ball valve 16 are opened, and the second ball valve 33 is closed. This allows high-pressure gas to be supplied through the first gas supply pipeline 10 to the solenoid valve of the hydrogen supply module connected to the first output terminal 17 until the high-pressure gauge 15 displays a pressure value reaching the first target pressure value. After reaching the target pressure, close the first needle valve 14, and then observe whether the pressure value displayed by the high-pressure gauge 15 decreases. If the pressure value displayed by the high-pressure gauge 15 maintains the first target pressure within the standard time, or if the pressure value decreased within the standard time does not exceed the standard pressure value, it indicates that the solenoid valve of the hydrogen supply module has passed the high-pressure airtightness test. If the pressure value decreased within the standard time exceeds the standard pressure value, observe whether the pressure value displayed by the low-pressure gauge 34 changes. If it changes, it indicates that the solenoid valve of the hydrogen supply module has internal leakage. If it does not change, a handheld concentration detector can be used to detect the gas concentration in the air near the solenoid valve of the hydrogen supply module to determine whether the solenoid valve of the hydrogen supply module has external leakage and to detect and identify the leaking component.

[0052] In some specific embodiments of this utility model, reference is made to Figure 1When it is necessary to test the airtightness of the solenoid valve of the hydrogen supply module in a low-pressure environment, i.e., low-pressure airtightness, the input terminal of the solenoid valve of the hydrogen supply module is connected to the first output terminal 17 of the first gas supply pipeline 10, and the output terminal of the solenoid valve of the hydrogen supply module is connected to the third output terminal 36 of the third gas supply pipeline 30. Based on the low-pressure value of the solenoid valve, a second target pressure value for the output gas pressure of the low-pressure gas source 21 is set, and a second preset pressure relief value for the second safety relief valve 23 is set. Then, the low-pressure gas source 21, the second throttle valve 22, the second needle valve 24, the one-way valve 25, and the three-way ball valve 16 are opened, and the first needle valve 14 and the second ball valve 33 are closed. This allows low-pressure gas to be supplied to the solenoid valve of the hydrogen supply module connected to the first output terminal 17 through the second gas supply pipeline 20 until the high-pressure gauge 15 displays... After the pressure value reaches the second target pressure, close the second needle valve 24 and observe whether the pressure value displayed by the high-pressure gauge 15 decreases. If the pressure value displayed by the high-pressure gauge 15 maintains the second target pressure within the standard time, or if the pressure value decreased by the high-pressure gauge 15 within the standard time does not exceed the standard pressure value, it indicates that the solenoid valve of the hydrogen supply module has passed the low-pressure airtightness test. If the pressure value decreased by the high-pressure gauge 15 within the standard time exceeds the standard pressure value, observe whether the pressure value in the low-pressure gauge 34 changes. If it changes, it indicates that the solenoid valve of the hydrogen supply module has internal leakage. If it does not change, a handheld concentration detector can be used to detect the gas concentration in the air near the solenoid valve of the hydrogen supply module to determine whether the solenoid valve of the hydrogen supply module has external leakage and to detect and identify the leaking component.

[0053] In some specific embodiments of this utility model, reference is made to Figure 1When it is necessary to test the airtightness of the gas-water separator, ejector, and hydrogen circulation pump in the hydrogen supply module under low-pressure conditions, i.e., to test the low-pressure airtightness of the gas-water separator, ejector, and hydrogen circulation pump separately, the input end of the gas-water separator, the input end of the ejector, or the input end of the hydrogen circulation pump in the hydrogen supply module is connected to the third output end 36 of the third gas supply pipeline 30. The third target pressure preset by the pressure reducing valve 32 and the third preset pressure relief value of the third safety relief valve 37 are set according to the low-pressure value of the gas-water separator, ejector, or hydrogen circulation pump. At this time, the low-pressure gas source 21 is still set as... The second target pressure value for the low-pressure airtightness test of the solenoid valve of the hydrogen supply module is directly adjusted by the pressure reducing valve to regulate the pressure of the gas supplied in the third gas pipeline 30, thus avoiding frequent adjustment of the pressure of the gas output from the low-pressure gas source 21. The second safety relief valve 23 is also set to the second preset relief value for the low-pressure airtightness test of the solenoid valve of the hydrogen supply module. This means that the airtightness testing device can simultaneously perform low-pressure airtightness tests on the solenoid valve, gas-liquid separator, ejector, and hydrogen circulation pump of the hydrogen supply module. Then, the low-pressure gas source 21, the second throttle valve 22, the first ball valve 31, and the... The pressure reducing valve 32 and the second ball valve 33 are used to supply low-pressure gas to the gas-liquid separator, ejector, or hydrogen circulation pump of the hydrogen supply module connected to the third output terminal 36 through the second gas supply pipeline 20 between the low-pressure gas source 21 and the third input terminal 35, and the third gas supply pipeline 30. The pressure reducing valve 32 reduces the pressure of the gas in the second gas supply pipeline 20 from a second target pressure value to a third target pressure value. When the low-pressure gauge 34 shows that the pressure value has reached the third target pressure, the second ball valve 33 is closed, and it is observed whether the pressure value displayed on the low-pressure gauge 34 has decreased. If... If the low-pressure gauge 34 displays a pressure value that maintains the third target pressure within a standard time, or if the pressure drop shown by the low-pressure gauge 34 within a standard time does not exceed the standard pressure value, it indicates that the vapor-liquid separator, ejector, or hydrogen circulation pump of the hydrogen supply module has passed the low-pressure airtightness test. If the pressure drop shown by the low-pressure gauge 34 within a standard time exceeds the standard pressure value, it indicates that there is an external leak in the vapor-liquid separator, ejector, or hydrogen circulation pump of the hydrogen supply module. A handheld concentration detector can be used to detect which component of the vapor-liquid separator, ejector, or hydrogen circulation pump is leaking. The operating pressure of the vapor-liquid separator, ejector, and hydrogen circulation pump generally does not exceed 3 barg, so it is not necessary to test the high-pressure airtightness of the vapor-liquid separator, ejector, and hydrogen circulation pump to avoid damage to the vapor-liquid separator, ejector, and hydrogen circulation pump due to high-pressure airtightness testing.

[0054] In some embodiments of this utility model, the hydrogen supply module further includes a hydrogen output terminal, which is used to connect to the tail gas treatment device through a ball valve during the airtightness test, so that the test gas in the third gas supply pipeline 30 can be discharged through the hydrogen output terminal after the test is completed.

[0055] In some embodiments of this utility model, when the tested component is a hydrogen supply module, both the high-pressure gas source 11 and the low-pressure gas source 21 are hydrogen gas sources, and the handheld concentration detector is a handheld hydrogen concentration detection sensor. The handheld hydrogen concentration detection sensor can accurately capture the traces of hydrogen in the air and issue an alarm before danger occurs.

[0056] In some embodiments of this invention, the handheld concentration detector includes an electrochemical sensor, a semiconductor sensor, a thermal conductivity sensor, and a catalytic combustion sensor.

[0057] Although the embodiments of this utility model have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of this utility model as described in the claims. Moreover, the utility model described herein may have other embodiments and can be implemented or realized in various ways.

Claims

1. An airtightness testing device, characterized in that, include: The first gas circuit unit includes a first gas supply pipeline, a high-pressure gas source, a first needle valve, a high-pressure gauge, and a three-way ball valve. The first input end of the first gas supply pipeline is connected to the high-pressure gas source, and the first output end of the first gas supply pipeline is used to connect to the device under test. The first needle valve, the high-pressure gauge, and the three-way ball valve are sequentially arranged in the first gas supply pipeline along the gas delivery direction in the first gas supply pipeline. The second gas circuit unit includes a low-pressure gas source, a second gas supply line and a second needle valve. The second input end of the second gas supply line is connected to the low-pressure gas source. The second output end of the second gas supply line is connected to the first gas supply line between the high-pressure gauge and the three-way ball valve. The second needle valve is located in the second gas supply line. The third gas supply unit includes a third gas supply line, a first ball valve, a pressure reducing valve, a second ball valve, and a low-pressure gauge. The third input end of the third gas supply line is connected to the second gas supply line between the low-pressure gas source and the second needle valve. The third output end of the third gas supply line is used to connect to the device under test. The first ball valve, the pressure reducing valve, the second ball valve, and the low-pressure gauge are sequentially arranged in the third gas supply line along the gas delivery direction.

2. The airtightness testing device according to claim 1, characterized in that, The second gas circuit unit further includes a one-way valve, which is disposed in the second gas supply line between the second needle valve and the second output end of the second gas supply line.

3. The airtightness testing device according to claim 1, characterized in that, The first gas circuit unit further includes a first safety relief valve, which is disposed in the first gas delivery pipeline between the high-pressure gas source and the first needle valve; The second gas circuit unit also includes a second safety relief valve, which is disposed in the second gas delivery pipeline between the low-pressure gas source and the second needle valve; The third gas circuit unit also includes a third safety relief valve, which is disposed in the third gas supply pipeline between the low pressure gauge and the third output terminal, or in the connecting pipeline between the third output terminal and the input terminal of the device under test.

4. The airtightness testing device according to claim 3, characterized in that, It also includes an exhaust gas treatment device, wherein the first safety relief valve, the pressure relief output end of the three-way ball valve, the second safety relief valve, and the third safety relief valve are all connected to the exhaust gas treatment device.

5. The airtightness testing device according to claim 3, characterized in that, The first gas circuit unit further includes a first throttle valve, which is disposed in the first gas delivery pipeline between the high-pressure gas source and the first safety relief valve; The second gas circuit unit further includes a second throttle valve, which is disposed in the second gas supply pipeline between the low-pressure gas source and the second safety relief valve.

6. The airtightness testing device according to claim 3, characterized in that, The first preset pressure relief value of the first safety relief valve is greater than the first target pressure value of the gas output from the high-pressure gas source; The second preset pressure relief value of the second safety relief valve is greater than the second target pressure value of the gas output from the low-pressure gas source; The third preset pressure relief value of the three safety relief valve is greater than the third preset target pressure value of the pressure reducing valve.

7. The airtightness testing device according to claim 6, characterized in that, The first target pressure value is greater than the second target pressure value, and the second target pressure value is greater than the third target pressure value; the first preset pressure relief value is greater than the second preset pressure relief value, and the second preset pressure relief value is greater than the third preset pressure relief value.

8. The airtightness testing device according to claim 1, characterized in that, The device under test includes a hydrogen supply module, which includes a solenoid valve, a vapor-water separator, an ejector, and a hydrogen circulation pump. The first output end of the first gas supply pipeline is used to connect to the input end of the solenoid valve, and the third output end of the third gas supply pipeline is used to connect to the output end of the solenoid valve, the input end of the vapor-water separator, the input end of the ejector, or the input end of the hydrogen circulation pump.

9. The airtightness testing device according to claim 6 or 7, characterized in that, The first target pressure value is greater than 8 barg and less than 20 barg; the second target pressure value is greater than 0 barg and less than or equal to 8 barg; the third target pressure value is greater than 0 barg and less than or equal to 3 barg.

10. The airtightness testing device according to claim 1, characterized in that, The airtightness testing device also includes a handheld concentration detector, the first output end of the first gas supply line is used to connect to the input end of the test device, and the third output end of the third gas supply line is used to connect to the output end of the test device.

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