Device for quickly and accurately positioning leakage point on surface of polar plate

Abstract

The utility model provides a pole plate surface leakage point rapid and accurate positioning device which comprises a tool upper plate, a tool lower plate, a leakage point positioning block, a blanking block and a positioning rod I. The tool upper plate and the tool lower plate are connected through the positioning rod I. The leakage point positioning block is connected with the blanking block and located above the tool upper plate. An experiment paper placing area and a blanking block moving area are arranged on the tool lower plate, and the blanking block is arranged in the blanking block moving area and drives the leakage point positioning block to move; a gas flow channel observation area is arranged at the top of the tool upper plate, a gas cavity inlet, a gas cavity outlet and a water cavity inlet are formed in the side wall of the tool upper plate, an observation mirror is arranged on the leakage point positioning block, a sight bead is arranged in the center of the observation mirror, and a blanking knife edge is arranged on the blanking block. According to the utility model, the leakage point on the surface of the polar plate can be quickly and accurately positioned, so that subsequent experiments such as observation and anomaly analysis on the leakage point are facilitated, and better conditions are created for the operation of a fuel cell.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell technology, and in particular to a device for rapid and accurate location of leaks on the surface of electrode plates. Background Technology

[0002] A fuel cell is a clean energy technology device that directly converts chemical energy into electrical energy. One of its key components is the electrode plates, which often number in the hundreds. During fuel cell operation, the electrode plates typically act as carriers for hydrogen, air, and water. The gases react on both sides of the plate through a proton exchange membrane, while the water removes the heat of reaction through the plate's interlayer. The gas chamber and water chamber exist independently. When abnormalities occur in the quality control of the electrode substrate, the electrode processing, or the use of the fuel cell stack, airtightness leaks caused by cross-contamination between the gas and water chambers frequently occur. This can have a significant deteriorating impact on the entire fuel cell stack operation, leading to safety hazards such as a sudden drop in output power or even stack burnout.

[0003] Leaks in interconnected air and water chambers are often micrometers in size, making them difficult to observe visually on a bipolar plate with a macroscopic dimension of hundreds of millimeters. Current methods for finding leaks often involve visual observation, microscopic examination, and dynamic visualization experiments. However, visual inspection or microscopic observation is time-consuming and labor-intensive, and prone to misjudgment or underjudgment. Visualization experiments (where the air chamber is filled with water and circulated, and the water chamber is filled with air, causing bubbles to form in the air chamber) can only reveal the location of the leak under dynamic conditions, but cannot mark it. When checking for leaks in suspected areas after disassembling the visualization fixture, factors such as plate material (graphite), durability corrosion, high-temperature discoloration, coating peeling, mechanical damage, and solder joint defects can interfere, making it equally time-consuming, labor-intensive, and prone to misjudgment or underjudgment.

[0004] Patent document CN218066927U discloses a fuel cell bipolar plate leak detection device, including a lower pressure plate and an upper pressure plate. A drive assembly controls the upper and lower pressure plates to clamp the bipolar plate. The lower pressure plate has a gas inlet connected to the flow channel of the bipolar plate. The gas inlet is connected to a pipeline, and a gas pressure detection device is installed on the pipeline. This invention reduces the overall size of the fuel cell bipolar plate leak detection device, thus reducing space occupancy. However, this device can only determine whether the bipolar plate is airtight; it cannot locate leaks in defective products.

[0005] Patent document CN114323466A discloses a leak detection device and method for fuel cell bipolar plates, including: a visualization clamp, a gas source, a water pump, and a water tank; the visualization clamp holds the bipolar plate, and water is supplied to the hydrogen chamber and the air chamber through pipelines, while gas is supplied to the water chamber. This invention utilizes a visualization end plate to determine the location and number of leaks in the bipolar plate by observing the generation of bubbles in the hydrogen chamber and the air chamber. However, this device can only observe the location and number of leaks in bipolar plates under dynamic conditions. After the device is removed, the exact location of the leak cannot be reliably found due to factors such as the material color of the bipolar plate and discoloration caused by overheating, and it is easily confused with other discolored points.

[0006] Patent document CN216717731U discloses a bipolar plate leak detection system, including: a positioning module, a water cavity pipeline, and an air cavity pipeline. The positioning module comprises multiple modules stacked from top to bottom, with upper and lower positioning areas formed between each pair of adjacent modules. Each positioning area is provided with a water cavity blind hole, an air cavity blind hole, a water cavity air inlet, and an air cavity air inlet. The water cavity blind holes and air cavity blind holes of each pair of adjacent positioning areas are connected. This invention can simultaneously detect the sealing performance of multiple bipolar plates, determine which specific bipolar plate is leaking, analyze whether the leak is due to water vapor leakage or external leakage within the water cavity, and identify whether the leak point is on the cathode or anode side of the bipolar plate. However, this device can only determine which side of the air cavity the leak is on, but cannot pinpoint the exact location of the leak on that side; it can only be used as a preliminary step for leak location.

[0007] The shortcomings of existing technology:

[0008] 1. Existing technologies are usually only used to determine whether the airtightness of the electrode plate is up to standard or the location of the leak point on the electrode plate, but they cannot provide the function of leak point location.

[0009] 2. Although the location and number of leaks can be seen in a dynamic experimental state through a visual fixture, it is still difficult to capture the location of leaks by manually marking them after disassembling the fixture. It is easily affected by factors such as plate material (graphite), durability corrosion, high temperature discoloration, coating peeling, mechanical damage, and solder joint defects, which can lead to misjudgment or omission and result in failure analysis of the wrong location.

[0010] 3. Using a high-magnification microscope for inspection requires a lot of time to find leaks on the entire plate surface, which is time-consuming and labor-intensive;

[0011] 4. When the electrode plate is a bipolar plate, which is made by stacking two plates, the leakage point between the gas cavity and the water cavity is usually a single-sided leakage, and the leakage point cannot be found by strong light penetration with the naked eye. Utility Model Content

[0012] To address the aforementioned technical problems, a device for rapidly and accurately locating leaks on the surface of electrode plates is provided. This invention enables rapid and accurate location of leaks on the electrode plate surface, facilitating subsequent observation and anomaly analysis, and creating better conditions for fuel cell operation. The technical means employed in this invention are as follows:

[0013] A device for rapid and accurate positioning of leak points on the surface of an electrode plate includes: an upper tooling plate, a lower tooling plate, a leak point positioning block, a punching block, and a positioning rod I. The upper tooling plate and the lower tooling plate are connected by the positioning rod I. The electrode plate is placed between the upper tooling plate and the lower tooling plate. The leak point positioning block is connected to the punching block and is located above the upper tooling plate. The lower tooling plate is provided with a test paper placement area and a punching block movable area located below the test paper placement area. The punching block is placed in the punching block movable area and moves within the punching block movable area with the leak point positioning block in it.

[0014] The top of the tooling plate is provided with a gas flow channel observation area, and the leak point positioning block is located above the gas flow channel observation area;

[0015] The side wall of the upper plate of the tooling is provided with an air cavity inlet, an air cavity outlet and a water cavity inlet. The air cavity inlet and the air cavity outlet are connected to the air cavity of the electrode plate, and the water cavity inlet is connected to the water cavity of the electrode plate.

[0016] The leak point positioning block is equipped with an observation mirror, the center of which contains a crosshair, and the punching block is equipped with a punching blade.

[0017] Furthermore, the upper plate of the tooling has multiple positioning holes I, and the lower plate of the tooling has multiple positioning holes II, with positioning rod I connected in each set of coaxial positioning holes I and positioning holes II.

[0018] Furthermore, the two ends of the punching block that extend through the moving area of ​​the punching block are connected to the leakage point positioning block via positioning rod II.

[0019] Furthermore, the leak point positioning block has positioning holes Ⅲ at both ends, and the punching block has positioning holes Ⅳ at both ends. Positioning rods Ⅱ are connected to the coaxial positioning holes Ⅲ and positioning holes Ⅳ on both sides.

[0020] Furthermore, the upper plate of the tooling is made of a transparent material.

[0021] Furthermore, the observation mirror and the punching blade are concentrically arranged.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The device for rapid and accurate location of leaks on the electrode surface provided by this utility model can directly capture and mark leaks during visual experiments, avoiding the inability to accurately locate the leaks after disassembling the tooling.

[0024] 2. The device for rapid and accurate positioning of leakage points on the electrode surface provided by this utility model has a punching block and an observation mirror that can move simultaneously to maintain their relative positions. That is, the position of the leakage point on the electrode plate that is aimed at by the observation mirror can be synchronously and accurately fed back to the experimental paper.

[0025] 3. The device for rapid and accurate positioning of leakage points on the electrode surface provided by this utility model has a fast positioning speed and can quickly locate all leakage points of the bipolar plate in one go, avoiding repeated operations.

[0026] 4. The device for rapid and accurate positioning of leakage points on the electrode surface provided by this utility model has high positioning accuracy, avoiding the time-consuming and laborious process of using the naked eye or instruments to inspect a large area of ​​the plate surface.

[0027] 5. The device for rapid and accurate positioning of leak points on the electrode surface provided by this utility model has high positioning accuracy and avoids misjudgment or missed judgment of leak points caused by factors such as electrode material (graphite), durability corrosion, high temperature discoloration, coating peeling, mechanical damage, and solder joint defects, which greatly improves the probability of making correct input for subsequent experiments.

[0028] Based on the above reasons, this utility model can be widely promoted in fields such as fuel cells. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the leak point positioning tooling structure of this utility model.

[0031] Figure 2 This is a schematic diagram of the upper plate structure of the tooling of this utility model.

[0032] Figure 3 This is a schematic diagram of the lower plate structure of the tooling of this utility model.

[0033] Figure 4 This is a schematic diagram of the positioning block and punching block of this utility model.

[0034] Figure 5 This is a schematic diagram of the tooling for locating leaks in the air chamber and water chamber of this utility model.

[0035] In the diagram: 1. Tooling upper plate; 1-1. Gas flow channel observation area; 1-2. Positioning hole I; 1-3. Gas cavity inlet; 1-4. Gas cavity outlet; 1-5. Water cavity inlet;

[0036] 2. Tooling lower plate; 2-1. Positioning hole II; 2-2. Experimental paper placement area; 2-3. Punching block moving area;

[0037] 3. Leakage point positioning block; 3-1. Observation mirror; 3-2. Positioning hole III;

[0038] 4. Punching block; 4-1. Punching blade; 4-2. Positioning hole IV;

[0039] 5. Positioning rod I; 6. Positioning rod II. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. 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 protection scope of this utility model.

[0041] Example 1

[0042] This invention provides a device for rapid and accurate location of leaks on electrode surfaces. It relates to a tooling system for quickly and accurately locating leaks that may occur on electrode plates made of materials such as metal / graphite after manufacturing or application. It is particularly applicable to the identification and analysis of abnormal leaks on the electrode surfaces of fuel cell stack modules after manufacturing and application. This invention offers high efficiency and accuracy in finding leaks, significantly improving the accuracy of leak detection and avoiding time losses and subsequent errors in failure analysis caused by difficulties in finding leaks and incorrect identification.

[0043] like Figure 1 As shown, this utility model discloses a device for rapid and precise positioning of leak points on the surface of an electrode plate, comprising: an upper tooling plate 1, a lower tooling plate 2, a leak point positioning block 3, a punching block 4, a positioning rod I 5, and a positioning rod II 6. The positioning rod I 5 can fix the relative positions of the upper tooling plate 1 and the lower tooling plate 2; the positioning rod II 6 can fix the relative positions of the leak point positioning block 3 and the punching block 4.

[0044] like Figure 2 As shown, the upper plate 1 of the tooling contains a gas flow channel observation area 1-1, two positioning holes I 1-2, a gas cavity inlet 1-3 and a gas cavity outlet 1-4 that are respectively connected to the gas cavity of the electrode plate, and a water cavity inlet 1-5 that is connected to the water cavity of the electrode plate.

[0045] like Figure 3As shown, the lower tooling plate 2 contains two positioning holes II 2-1, a test paper placement area 2-2, and a punching block moving area 2-3. The test paper placement area 2-2 is above the punching block moving area 2-3.

[0046] like Figure 4 As shown, the leak point positioning block 3 contains an observation mirror 3-1 and two positioning holes III 3-2, which are arranged at both ends of the leak point positioning block 3. The punching block 4 contains a punching blade 4-1 and two positioning holes IV 4-2, which are arranged at both ends of the punching block 4.

[0047] The two positioning holes I1-2 on the upper tooling plate 1 and the two positioning holes II2-1 on the lower tooling plate 2 are concentric and the same size as the positioning holes on the electrode plate. The upper tooling plate 1, the lower tooling plate 2 and the electrode plate can be positioned by the positioning rod I5 through the positioning holes I1-2, the positioning holes II2-1 and the positioning holes on the electrode plate.

[0048] The upper plate 1 of the tooling is made of transparent material to ensure the visualization of the leak location experiment, so that the experimental situation can be observed through the gas flow observation area 1-1.

[0049] The leak location block 3 can move within a range above the gas flow channel observation area 1-1;

[0050] The observation mirror 3-1 can observe the state of the gas flow channel area and can observe the experimental state through the observation area 1-1 of the gas flow channel. The observation mirror 3-1 has a crosshair in the center, which can be used to aim at the leak point and can be used to accurately aim at the leak point where the bubble is generated.

[0051] The two positioning holes Ⅲ3-2 of the leak point positioning block 3 are the same size and concentric with the two positioning holes Ⅳ4-2 of the punching block 4. The leak point positioning block 3 and the punching block 4 can be positioned by the positioning rod Ⅱ6 through the positioning holes Ⅲ3-2 and Ⅳ4-2, so that the punching block 4 can move simultaneously with the leak point positioning block 3. The punching block 4 can move above the punching block movable area 2-3.

[0052] The punching block 4 can move within the punching block moving area 2-3, and the punching blade 4-1 is concentric with the observation mirror 3-1.

[0053] Example 2

[0054] like Figure 5 As shown, the positioning method of the device for rapid and accurate positioning of leakage points on the surface of an electrode plate according to this utility model is as follows:

[0055] S1. Place the lower tooling plate 2 on the press platform;

[0056] S2. With the side of the electrode plate where the leakage point needs to be located facing upwards, align the positioning hole of the electrode plate with the positioning hole II2-1 of the lower tooling plate 2, and place it on the lower tooling plate 2. Place the pre-made experimental paper (with positioning holes of the same size and concentricity as the positioning holes of the electrode plate, light-colored, non-transparent, easy to cut, and sized to fit perfectly into the experimental paper placement area 2-2) into the experimental paper placement area 2-2 of the lower tooling plate 2. Use two positioning rods I5 to pass through the positioning holes of the electrode plate and the positioning holes 2-1 of the experimental paper and the lower tooling plate 2 to fix the position.

[0057] S3. Place the upper tooling plate 1 above the electrode plate, and fix the position of the positioning holes I1-2 of the upper tooling plate 1 by the positioning rod I5;

[0058] S4. Place two identical pads above the upper plate 1 of the tooling to expose the gas flow observation area 1-1;

[0059] S5. Operate the press head to descend, press the press head down above the pad block, and stop the press after reaching the specified assembly force;

[0060] S6. Pass deionized water into the air chamber inlet 1-3 of the upper plate 1 of the tooling to fill the air chamber with deionized water. Circulate water through the air chamber inlet 1-3 and the air chamber outlet 1-4. Control the flow rate of the circulating water to keep the air chamber full of deionized water. The flow rate of the circulating water should not be too fast so that the air bubbles can move slowly in the air chamber, making it easier to observe the leak.

[0061] S7. Introduce compressed air of about 50KPA-100KPA into the water cavity inlets 1-5 of the upper plate 1 of the tooling. The air pressure should not be too high, so that bubbles can be generated slowly and continuously at the leak point.

[0062] S8. Place the punching block 4 into the punching block active area 2-3 of the tooling lower plate 2;

[0063] S9. Place the leak location block 3 into the gas flow channel observation area 1-1 of the upper plate of the tooling;

[0064] S10. Pass the two positioning rods II6 through the positioning hole III3-2 of the leak point positioning block 3 and the positioning hole IV4-2 of the punching block 4, so that the punching block 4 and the leak point positioning block 3 can move simultaneously.

[0065] S11. Because compressed air is introduced into the water chamber and deionized water is used for water circulation in the air chamber, the leak point between the air chamber and the water chamber will continuously generate visible bubbles, which can be seen visually in the gas flow channel observation area 1-1.

[0066] S12. Move the leak point positioning block 3 so that the source of the bubble generated by the leak point is within the visible range of the observation mirror 3-1, and align the crosshair on the observation mirror 3-1 with the source of the bubble (leak point).

[0067] S13. After locating the leak point using the observation mirror 3-1, lift the punching block 4. The punching blade 4-1 on the punching block 4 will leave the specific location of the leak point on the experimental paper.

[0068] S14. If there are multiple leaks, repeat steps S12-S13;

[0069] S15. Stop water circulation, drain deionized water, stop compressed air to release pressure, raise the press to the specified height, remove the pad, pull out the positioning rod II6, and remove the leak point positioning block 3 and the punching block 4.

[0070] S16. Pull out the positioning rod I5, remove the upper plate 1 of the tooling, remove the electrode plate, and remove the experimental paper;

[0071] S17. By passing the positioning rod I5 through the positioning hole of the experimental paper and the positioning hole of the electrode plate, the experimental paper can be attached to the electrode plate, thus obtaining the precise location of the leak point. Subsequently, a high-powered microscope can be used to observe the leak point or conduct other analytical experiments within this precise range.

[0072] This invention offers the following advantages: 1. It allows for direct leak location marking on experimental paper using a punch block and observation lens during dynamic experiments, preventing the inability to accurately locate leaks after disassembling the fixture; 2. It enables rapid and one-time location of all leaks on the electrode plate, saving time; 3. It avoids the need for extensive visual or instrument-based inspection of the electrode plate surface, reducing human and time consumption; 4. It avoids interference from factors such as electrode plate material (graphite), durability corrosion, high-temperature discoloration, plating peeling, mechanical damage, and solder joint defects in leak location.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A device for rapid and accurate location of leak points on the surface of an electrode plate, characterized in that, include: The fixture consists of an upper plate (1), a lower plate (2), a leak point positioning block (3), a punching block (4), and a positioning rod I (5). The upper plate (1) and the lower plate (2) are connected by the positioning rod I (5). The pole plate is placed between the upper plate (1) and the lower plate (2). The leak point positioning block (3) is connected to the punching block (4) and is located above the upper plate (1). The lower plate (2) has a test paper placement area (2-2) and a punching block moving area (2-3) located below the test paper placement area (2-2). The punching block (4) is placed in the punching block moving area (2-3) and moves in the punching block moving area (2-3) with the leak point positioning block (3). The top of the tooling plate (1) is provided with a gas flow channel observation area (1-1), and the leak point positioning block (3) is located above the gas flow channel observation area (1-1); The side wall of the tooling upper plate (1) is provided with an air cavity inlet (1-3), an air cavity outlet (1-4), and a water cavity inlet (1-5). The air cavity inlet (1-3) and the air cavity outlet (1-4) are connected to the electrode plate air cavity, and the water cavity inlet (1-5) is connected to the electrode plate water cavity. The leak point positioning block (3) is provided with an observation mirror (3-1), the center of which contains a crosshair, and the punching block (4) is provided with a punching blade (4-1).

2. The device for rapid and accurate location of leak points on the electrode surface according to claim 1, characterized in that, The upper plate (1) of the fixture has multiple positioning holes I (1-2), and the lower plate (2) of the fixture has multiple positioning holes II (2-1). Positioning rod I (5) is connected in each set of coaxial positioning holes I (1-2) and positioning holes II (2-1).

3. The device for rapid and accurate location of leak points on the electrode surface according to claim 1, characterized in that, The two ends of the punching block (4) extending through the punching block moving area (2-3) are connected to the leakage point positioning block (3) via positioning rod II (6).

4. The device for rapid and accurate location of leak points on the electrode surface according to claim 3, characterized in that, The leak point positioning block (3) has positioning holes Ⅲ (3-2) at both ends, and the punching block (4) has positioning holes Ⅳ (4-2) at both ends. Positioning rods Ⅱ (6) are connected to the coaxial positioning holes Ⅲ (3-2) and positioning holes Ⅳ (4-2) on both sides.

5. The device for rapid and accurate location of leak points on the electrode surface according to claim 1, characterized in that, The tooling upper plate (1) is made of transparent material.

6. The device for rapid and accurate location of leak points on the electrode surface according to claim 1, characterized in that, The observation mirror (3-1) and the cutting edge (4-1) are arranged concentrically.

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