Electric pile inner leakage detection equipment and detection method

Abstract

The invention relates to electric pile inner leakage detection equipment and a detection method. The electric pile inner leakage detection equipment comprises a detection table, a visual detector and a gas supply assembly, an airtight pressing plate is arranged on the detection table, the detection table is used for placing a to-be-detected galvanic pile, and the airtight pressing plate is used for sealing a hydrogen cavity and a cavity of the to-be-detected galvanic pile; the visual detector is used for extending into a water cavity of a to-be-detected galvanic pile and scanning and photographing the interior of the water cavity; the gas supply assembly is communicated with the hydrogen cavity and the cavity of the galvanic pile to be tested and is used for injecting gas into the hydrogen cavity and the cavity. Compared with the prior art, the visual detector is used for scanning and photographing, whether the battery leaks air or not can be judged according to whether the battery has air bubbles or not, and the specific position of which battery leaks air can be judged according to the position of the air bubbles; according to the invention, the inner leakage battery can be prevented from being searched in a manner of disassembling the stack to test the air tightness of the battery or sequentially assembling the short stacks, and the inner leakage test efficiency and the inner leakage position test accuracy of the electric pile are effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of gas tightness detection of battery stacks, and in particular to a device and method for detecting internal leakage of a battery stack. Background Art

[0002] A hydrogen fuel cell is a power generation device that converts the chemical energy of hydrogen and oxygen directly into electrical energy. Its basic principle is the reverse reaction of water electrolysis. Hydrogen and oxygen are supplied to the anode and cathode respectively. After hydrogen diffuses outward through the anode and reacts with the electrolyte, it releases electrons to reach the cathode through an external load. Fuel cells are environmentally friendly. They produce only water and heat through electrochemical reactions, rather than releasing pollutants such as COx, NOx, SOx gases and dust like combustion. Fuel cells operate quietly, so hydrogen fuel cells are a clean and quiet energy source.

[0003] During the production and testing of fuel cell stacks, the gas tightness test of the stack is a very critical process, and the results of the gas tightness test are directly related to the performance and safety of the stack. Existing detection methods can often only lock the leakage position of the stack through the water immersion method or the leak detection liquid method, but there is no solution to accurately lock the leaking battery position for the internal leakage of the stack hydrogen-air water. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a battery stack internal leakage detection device and a detection method, so as to improve the efficiency of battery stack internal leakage testing and the accuracy of internal leakage position testing.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A stack internal leakage detection device, comprising:

[0007] A test bench, wherein an airtight pressure plate is provided on the test bench, the test bench is used to place the battery stack to be tested, and the airtight pressure plate is used to seal the hydrogen cavity and the cavity of the battery stack to be tested;

[0008] A visual inspection instrument, which is used to extend into the water cavity of the battery stack to be tested and scan and photograph the interior of the water cavity;

[0009] A gas supply component is connected to the hydrogen chamber and the cavity of the fuel cell stack to be tested, and is used to inject gas into the hydrogen chamber and the cavity.

[0010] In one of the embodiments, a detection bracket is provided on the detection platform, and the detection bracket is connected to the visual detection instrument.

[0011] In one of the embodiments, the detection bracket includes a guide rail arranged along the horizontal direction, and the visual inspection instrument is slidably matched with the guide rail.

[0012] In one embodiment, the detection bracket includes a guide rod and a middle piece, the guide rod is connected to the visual detection instrument, the middle piece is slidably matched with the guide rail, the guide rod is movably matched with the middle piece, and the guide rod can extend into or out of the water cavity of the battery stack to be tested in a vertical direction.

[0013] In one of the embodiments, a push rod motor is provided on the guide rod, and the push rod motor is connected to the middle piece and is used to drive the guide rod to move in a vertical direction.

[0014] In one of the embodiments, a pressure plate bracket is provided on the testing platform, and the pressure plate bracket is movably connected to the airtight pressure plate, and the airtight pressure plate can approach or move away from the testing platform in a vertical direction.

[0015] In one embodiment, the pressure plate bracket includes a guide column and a screw rod arranged in a vertical direction, the guide column is movably passed through the airtight pressure plate, the screw rod is in transmission cooperation with the airtight pressure plate, and a driving member is provided on the screw rod for driving the screw rod to rotate.

[0016] In one embodiment, the gas supply assembly includes a gas supply pipeline and a gas source, the airtight pressure plate is provided with air holes, the air holes are connected to the hydrogen chamber and the cavity of the fuel cell stack to be tested, and the two ends of the gas supply pipeline are respectively connected to the air holes and the gas source.

[0017] In one of the embodiments, an end plate is provided on the test stack, a hydrogen cavity inlet hole and a cavity inlet hole are provided on the end plate, and a sealing ring is provided between the air hole of the airtight pressure plate and the hydrogen cavity inlet hole and the cavity inlet hole.

[0018] A method for detecting internal leakage of a battery stack, using the above-mentioned internal leakage detection device of a battery stack, comprises the following steps:

[0019] Inject water into the water cavity of the battery stack to be tested;

[0020] Place the battery stack to be tested on the test bench;

[0021] Using an airtight pressure plate to seal the battery stack to be tested;

[0022] The gas supply assembly is used to inject gas into the hydrogen cavity and the cavity of the battery stack to be tested;

[0023] Insert the visual inspection instrument into the water cavity of the battery stack to be tested, and scan and take pictures of the inside of the water cavity;

[0024] Determine whether there are bubbles and determine the location of the bubbles based on the scanning and photographing results of the visual inspection instrument.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The above-mentioned internal leakage detection equipment for the battery stack is provided with a detection table for placing the battery stack to be tested, an airtight pressure plate for sealing the battery stack to be tested, a gas supply component for gas injection, and a visual detector capable of extending into the water cavity. During use, water can be first injected into the water cavity of the battery stack to be tested, and the battery stack to be tested can be placed on the detection table at the same time. The battery stack to be tested can be further sealed by the airtight pressure plate, and the gas supply component can inject gas into the hydrogen cavity and the cavity of the battery stack to be tested. Finally, the visual detector is extended into the water cavity of the battery stack to be tested to scan and photograph the inside of the water cavity; whether there are bubbles and the location of the bubbles can be determined based on the scanning and photographing results of the visual detector; the gas supply When the components inject gas into the hydrogen cavity and the cavity for pressurization, the battery with internal leakage in the fuel cell stack will produce bubbles in the water cavity. Therefore, by scanning and taking pictures with a visual inspection instrument, it is possible to determine whether the battery is leaking based on whether there are bubbles in the battery, and to determine which specific battery and where the leak is occurring based on the location of the bubbles. This can avoid the need to find the internal leaking battery by dismantling the stack and retesting the battery air tightness or assembling short stacks one by one, effectively improving the efficiency of the fuel cell stack internal leakage test and the accuracy of the internal leakage position test, accurately locking the location of the internal leaking fuel cell, and quickly repairing and replacing the leaking fuel cell stack, thereby speeding up the production rhythm and avoiding the waste of production manpower and equipment resources.

[0027] 2. A detection bracket is set on the detection table, and a guide rail is further set on the detection bracket, so that the visual inspection instrument can move in the horizontal direction along the guide rail. Therefore, the visual inspection instrument can scan and photograph the water cavity of the battery stack to be tested at different positions in the horizontal direction, thereby improving the detection efficiency and accuracy.

[0028] 3. At the same time, there is a guide rod on the detection bracket, so the visual inspection instrument can move in the vertical direction of the battery stack with the guide rod, which not only facilitates the visual inspection instrument to extend into and out of the water cavity of the battery stack to be tested, but also can scan and photograph the water cavity of the battery stack to be tested at different positions in the height direction, effectively determine the position of the bubble, and determine the height position of the leaking battery.

[0029] 4. The airtight pressure plate is connected to the test bench through a pressure plate bracket, and the pressure plate bracket includes a guide column and a screw rod. Therefore, the airtight pressure plate can be driven to move in the vertical direction by rotating the screw rod, so as to move closer to or away from the test bench. When the airtight pressure plate is away from the test bench, it can provide more operating space for placing the battery stack to be tested on the test bench. After the battery stack to be tested is placed on the test bench, the airtight pressure plate approaches the test bench until the airtight pressure plate presses the battery stack to be tested, thereby achieving the sealing of the battery stack to be tested.

[0030] 5. Air holes are arranged on the airtight pressure plate, and the gas supply assembly is connected with the hydrogen cavity and the air cavity of the fuel cell stack to be tested through the air holes of the airtight pressure plate. At the same time, sealing rings are arranged between the air holes of the airtight pressure plate and the hydrogen cavity inlet holes and the air cavity inlet holes, which is beneficial to improve the effectiveness of the sealing of the fuel cell stack to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the stack internal leakage detection equipment in the present invention.

[0032] Figure 2 It is a structural schematic diagram of the detection platform in the present invention.

[0033] Figure 3 It is a schematic diagram of the structure of the detection bracket and the visual detection instrument in the present invention.

[0034] Figure 4 It is a schematic diagram of the structure of the battery stack to be tested in the present invention.

[0035] Figure 5 It is a schematic diagram of the structure of the visual inspection instrument and the battery stack to be tested in the present invention.

[0036] Figure numerals: 100, stack internal leakage detection equipment; 10, test bench; 11, airtight pressure plate; 111, pipeline connection part; 112, avoidance hole; 12, pressure plate bracket; 121, guide column; 122, screw rod; 20, visual inspection instrument; 30, inspection bracket; 31, guide rail; 32, guide rod; 33, intermediate piece; 34, push rod motor; 40, stack to be tested; 41, hydrogen cavity entry hole; 42, cavity entry hole; 43, water cavity entry hole; 44, water cavity. DETAILED DESCRIPTION

[0037] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0038] The following describes in detail the stack internal leakage detection device 100 and the detection method in some embodiments with reference to the accompanying drawings.

[0039] like Figure 1 As shown, in one embodiment, a stack internal leakage detection device 100 is provided, including a detection table 10, a visual detection instrument 20 and a gas supply assembly;

[0040] Among them, an airtight pressure plate 11 is provided on the test platform 10, and the test platform 10 is used to place the battery stack 40 to be tested, and the airtight pressure plate 11 is used to seal the hydrogen cavity and cavity of the battery stack 40 to be tested; the visual inspection instrument 20 is used to extend into the water cavity 44 of the battery stack 40 to be tested, and scan and photograph the interior of the water cavity 44; the gas supply component is connected to the hydrogen cavity and cavity of the battery stack 40 to be tested, and is used to inject gas into the hydrogen cavity and cavity.

[0041] The above-mentioned battery stack internal leakage detection equipment 100 is provided with a detection table 10 for placing the battery stack to be tested 40, an airtight pressure plate 11 for sealing the battery stack to be tested 40, a gas supply component for gas injection, and a visual inspection instrument 20 capable of extending into the water cavity 44. During use, water can be first injected into the water cavity 44 of the battery stack to be tested 40, and the battery stack to be tested 40 can be placed on the detection table 10 at the same time. The airtight pressure plate 11 is further used to seal the battery stack to be tested 40, and the gas supply component injects gas into the hydrogen cavity and the cavity of the battery stack to be tested 40. Finally, the visual inspection instrument 20 is extended into the water cavity 44 of the battery stack to be tested 40 to scan and photograph the interior of the water cavity 44; according to the scanning and photographing results of the visual inspection instrument 20, it is judged whether There are bubbles and the location of the bubbles; when the gas supply component injects gas into the hydrogen chamber and the cavity for pressurization, the battery with internal leakage in the battery stack will generate bubbles in the water cavity 44. Therefore, by scanning and taking pictures with the visual inspection instrument 20, it is possible to judge whether the battery is leaking based on whether there are bubbles in the battery, and to judge which specific battery and where the leak is occurring based on the location of the bubbles. This can avoid finding the internal leaking battery by dismantling the stack to retest the battery air tightness or assembling short stacks in sequence, effectively improving the efficiency of the battery stack internal leakage test and the accuracy of the internal leakage position test, accurately locking the position of the internal leaking fuel cell, and quickly repairing and replacing the leaking battery stack, thereby speeding up the production rhythm and avoiding the waste of production manpower and equipment resources.

[0042] Specifically, Figure 1 and Figure 3 As shown, in one embodiment, a detection bracket 30 is provided on the detection platform 10 , and the detection bracket 30 is connected to the visual inspection instrument 20 .

[0043] Furthermore, if Figure 3 As shown, in one embodiment, the detection bracket 30 includes a guide rail 31 arranged along the horizontal direction, and the visual inspection instrument 20 is slidably matched with the guide rail 31.

[0044] A detection bracket 30 is set on the detection table 10, and a guide rail 31 is further set on the detection bracket 30, so that the visual inspection instrument 20 can move in the horizontal direction along the guide rail 31. Therefore, the visual inspection instrument 20 can scan and photograph the water cavity 44 of the battery stack 40 to be tested at different positions in the horizontal direction, thereby improving the detection efficiency and accuracy.

[0045] Furthermore, if Figure 3 As shown, in one embodiment, the detection bracket 30 includes a guide rod 32 and a middle piece 33, the guide rod 32 is connected to the visual inspection instrument 20, the middle piece 33 is slidably matched with the guide rail 31, the guide rod 32 and the middle piece 33 are movably matched, and the guide rod 32 can extend into or out of the water cavity 44 of the battery stack 40 to be tested in the vertical direction.

[0046] There is also a guide rod 32 on the detection bracket 30, so the visual inspection instrument 20 can move in the vertical direction of the battery stack along with the guide rod 32, which not only facilitates the visual inspection instrument 20 to extend into and out of the water cavity 44 of the battery stack 40 to be tested, but also can scan and photograph the water cavity 44 of the battery stack 40 to be tested at different positions in the height direction, effectively determine the position of the bubbles, and determine the height position of the leaking battery.

[0047] Furthermore, if Figure 3 As shown, in one embodiment, a push rod motor 34 is provided on the guide rod 32, and the push rod motor 34 is connected to the middle piece 33 for driving the guide rod 32 to move in the vertical direction.

[0048] In one embodiment, a pressure plate bracket 12 is provided on the testing platform 10 , and the pressure plate bracket 12 is movably connected to the airtight pressure plate 11 , and the airtight pressure plate 11 can approach or move away from the testing platform 10 in the vertical direction.

[0049] In this specific embodiment, the visual inspection instrument 20 can be a camera with a waterproof function, and the visual inspection instrument 20 is also provided with a lighting lamp for illuminating the area scanned and photographed by the visual inspection instrument 20 to improve the detection accuracy of the visual inspection instrument 20.

[0050] Furthermore, if Figure 1 and Figure 5 As shown, in one embodiment, an avoidance hole 112 parallel to the guide of the guide rail 31 is provided on the airtight pressure plate 11, and a water cavity inlet hole 43 is provided on the end plate of the battery stack to be tested. Therefore, the visual inspection instrument 20 can pass through the avoidance hole 112 and the water cavity inlet hole 43 in turn to enter the water cavity and scan and photograph the interior of the water cavity 44.

[0051] Specifically, Figure 1 and Figure 2 As shown, in one embodiment, the pressure plate bracket 12 includes a guide column 121 and a screw rod 122 arranged along the vertical direction. The guide column 121 is movably arranged in the airtight pressure plate 11, and the screw rod 122 is in transmission cooperation with the airtight pressure plate 11. A driving member is provided on the screw rod 122 for driving the screw rod 122 to rotate.

[0052] The airtight pressure plate 11 is connected to the test bench 10 through a pressure plate bracket 12, and the pressure plate bracket 12 includes a guide column 121 and a screw 122. Therefore, the airtight pressure plate 11 can be driven to move in a vertical direction by rotating the screw 122, so as to move closer to or away from the test bench 10. When the airtight pressure plate 11 is away from the test bench 10, more operating space can be provided for placing the battery stack 40 to be tested on the test bench 10. After the battery stack 40 to be tested is placed on the test bench 10, the airtight pressure plate 11 approaches the test bench 10 until the airtight pressure plate 11 presses the battery stack 40 to be tested, thereby achieving the sealing of the battery stack 40 to be tested.

[0053] like Figure 2 As shown, in this specific embodiment, there are four guide posts 121, which are respectively located at the four corners of the airtight pressure plate 11, and there are two screw rods 122, which are arranged on both sides of the airtight pressure plate 11, which is conducive to improving the smoothness and stability of the movement of the airtight pressure plate 11. At the same time, the area enclosed by the four guide posts 121 and the two screw rods 122 is used to place the battery stack 40 to be tested, providing space for placing the battery stack 40 to be tested.

[0054] Specifically, in one embodiment, the gas supply assembly includes a gas supply pipeline and a gas source. The airtight pressure plate 11 is provided with air holes, which are connected to the hydrogen chamber and the cavity of the test stack 40. The two ends of the gas supply pipeline are respectively connected to the air holes and the gas source.

[0055] Specifically, Figure 4 As shown, in one embodiment, an end plate is provided on the test stack 40, and a hydrogen cavity inlet hole 41 and a cavity inlet hole 42 are provided on the end plate, and a sealing ring is provided between the air hole of the airtight pressure plate 11 and the hydrogen cavity inlet hole 41 and the cavity inlet hole 42.

[0056] Air holes are arranged on the airtight pressure plate 11, and the gas supply assembly is connected with the hydrogen chamber and the cavity of the test stack 40 through the air holes of the airtight pressure plate 11. At the same time, sealing rings are arranged between the air holes of the airtight pressure plate 11 and the hydrogen chamber inlet hole 41 and the cavity inlet hole 42, which is beneficial to improve the sealing effectiveness of the test stack 40.

[0057] Furthermore, if Figure 1 and Figure 4 As shown, in one embodiment, two gas supply pipes are provided, and two air holes are provided on the airtight pressing plate 11. The gas supply pipes correspond to the air holes one by one, and are respectively connected to the hydrogen cavity inlet hole 41 and the cavity inlet hole 42. A pipe connecting portion 111 is provided on the airtight pressing plate 11, which is used to connect the gas supply pipe and connect the air holes inside the airtight pressing plate 11.

[0058] In this specific embodiment, a solenoid valve and a pressure gauge are also provided on the gas supply pipeline. The solenoid valve is used to control the switch of the gas supply pipeline, and the pressure gauge is used to monitor the internal inflation pressure of the hydrogen chamber and the cavity of the test stack 40. When the pressure gauge shows that the pressure reaches the preset pressure, the solenoid valve is closed and the inflation of the hydrogen chamber and the cavity of the test stack 40 is stopped.

[0059] In one embodiment, a method for detecting internal leakage of a battery stack is provided, using the above-mentioned internal leakage detection device 100 of the battery stack, and comprising the following steps:

[0060] Injecting water into the water chamber 44 of the battery stack 40 to be tested;

[0061] Placing the battery stack 40 to be tested on the testing table 10;

[0062] The gas-tight pressure plate 11 is used to seal the test stack 40;

[0063] Injecting gas into the hydrogen cavity and the cavity of the test stack 40 using a gas supply assembly;

[0064] The visual inspection instrument 20 is inserted into the water cavity 44 of the battery stack 40 to be tested, and the interior of the water cavity 44 is scanned and photographed;

[0065] Whether there are bubbles and the location of the bubbles are determined based on the scanning and photographing results of the visual detector 20.

[0066] Specifically, in one embodiment, the battery stack internal leakage detection device 100 also includes a computing module, which is connected to the visual inspection instrument 20. The visual inspection instrument 20 transmits the scanning and photographing results to the computing module. The computing module identifies and determines the bubbles in the scanning and photographing results (such as photos), obtains the number of scanned batteries, and calculates the number of battery cells where the bubbles occur through the counting function, thereby realizing the function of accurately locking the internal leakage position.

[0067] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0068] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0069] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0071] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0072] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A stack internal leakage detection device, characterized in that: include: A test bench (10), wherein an airtight pressure plate (11) is provided on the test bench (10), the test bench (10) is used to place a battery stack (40) to be tested, and the airtight pressure plate (11) is used to seal the hydrogen cavity and the cavity of the battery stack (40) to be tested; A visual inspection instrument (20), the visual inspection instrument (20) being used to extend into the water cavity (44) of the battery stack (40) to be tested, and to scan and photograph the interior of the water cavity (44); A gas supply component is connected to the hydrogen chamber and the cavity of the test stack (40) and is used to inject gas into the hydrogen chamber and the cavity.

2. A stack internal leakage detection device according to claim 1, characterized in that: The detection platform (10) is provided with a detection bracket (30), and the detection bracket (30) is connected to the visual detection instrument (20).

3. The stack internal leakage detection device according to claim 2, characterized in that: The detection bracket (30) comprises a guide rail (31) arranged in a horizontal direction, and the visual detection instrument (20) is slidably matched with the guide rail (31).

4. The stack internal leakage detection device according to claim 3, characterized in that: The detection bracket (30) comprises a guide rod (32) and a middle piece (33); the guide rod (32) is connected to the visual detection instrument (20); the middle piece (33) is slidably matched with the guide rail (31); the guide rod (32) and the middle piece (33) are movably matched; the guide rod (32) can extend into or out of the water cavity (44) of the battery stack (40) to be tested in a vertical direction.

5. The stack internal leakage detection device according to claim 4, characterized in that: The guide rod (32) is provided with a push rod motor (34), and the push rod motor (34) is connected to the middle piece (33) and is used to drive the guide rod (32) to move in a vertical direction.

6. The stack internal leakage detection device according to claim 1, characterized in that: A pressure plate bracket (12) is provided on the detection platform (10), and the pressure plate bracket (12) is movably connected to the airtight pressure plate (11). The airtight pressure plate (11) can approach or move away from the detection platform (10) in a vertical direction.

7. The stack internal leakage detection device according to claim 6, characterized in that: The pressure plate bracket (12) includes a guide column (121) and a screw rod (122) arranged in a vertical direction. The guide column (121) is movably inserted into the airtight pressure plate (11). The screw rod (122) is in transmission cooperation with the airtight pressure plate (11). A driving member is provided on the screw rod (122) for driving the screw rod (122) to rotate.

8. The stack internal leakage detection device according to claim 1, characterized in that: The gas supply assembly comprises a gas supply pipeline and a gas source, the gas-tight pressure plate (11) is provided with a gas hole, the gas hole is connected to the hydrogen chamber and the cavity of the test stack (40), and the two ends of the gas supply pipeline are respectively connected to the gas hole and the gas source.

9. The stack internal leakage detection device according to claim 8, characterized in that: The test stack (40) is provided with an end plate, the end plate is provided with a hydrogen cavity inlet hole (41) and a cavity inlet hole (42), and a sealing ring is provided between the air hole of the airtight pressure plate (11) and the hydrogen cavity inlet hole (41) and the cavity inlet hole (42).

10. A method for detecting internal leakage of a battery stack, characterized in that: The stack internal leakage detection device according to any one of claims 1 to 9 comprises the following steps: Injecting water into a water chamber (44) of a battery stack (40) to be tested; Placing a battery stack (40) to be tested on a testing platform (10); Using an airtight pressure plate (11) to seal the battery stack (40) to be tested; Using a gas supply component to inject gas into the hydrogen cavity and the cavity of the battery stack (40) to be tested; Inserting a visual inspection instrument (20) into a water cavity (44) of a battery stack (40) to be tested, and scanning and photographing the interior of the water cavity (44); Whether there are bubbles and the location of the bubbles are determined based on the scanning and photographing results of the visual detector (20).

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