Air tightness detection device for flow battery

Abstract

The utility model discloses an air tightness detection device of a redox flow battery, which comprises a tray, a pressure plate, a clamp, a sealing element and a gas pipeline, a pressure gauge and a valve are arranged on the gas pipeline, a vent groove is arranged at the upper end of the tray, a vent hole communicated with the gas pipeline is arranged at the bottom of the vent groove, and the pressure gauge is arranged between the tray and the valve. The bottom face of the to-be-tested piece can seal a notch of the vent groove to form a gas cavity in the vent groove, the bottom face of the pressing disc can be tightly connected with the upper end of the to-be-tested piece, a plurality of through holes communicating the upper end face and the lower end face of the pressing disc are formed in the pressing disc at intervals, and the clamp is used for clamping the tray and the pressing disc. The air tightness detection device of the redox flow battery is simple in overall structure, convenient to detect and operate, high in air tightness detection efficiency and capable of accurately detecting the position where air leakage occurs.

Description

Technical Field

[0001] The utility model belongs to the technical field of sealing detection, and in particular relates to an airtightness detection device for a liquid flow battery. Background Art

[0002] Energy is a crucial pillar driving the development of modern society. With the advancement of civilization, the demand for energy is also increasing. As a non-renewable energy source, traditional fossil fuels face the risk of future depletion. Therefore, renewable energy sources, including solar, wind, and tidal energy, have experienced rapid growth in recent years, gradually replacing traditional energy sources. However, the unstable and discontinuous nature of renewable energy necessitates intermediate regulation during grid connection for proper, effective, and safe operation. Energy storage is a key technology to address this issue and is gaining increasing attention worldwide.

[0003] Flow batteries are an electrochemical energy storage technology that stores and converts energy through redox reactions between elements of different valence states. Because they store electrical energy in a flowing electrolyte, they offer advantages such as flexible system design, large storage capacity, safety, and environmental friendliness. Furthermore, because they do not involve phase changes during the electrode reaction, flow batteries offer excellent stability, high energy conversion efficiency, deep discharge capability, and safety and environmental friendliness, promising broad application prospects in the energy storage field. Flow batteries are typically assembled in a layered fashion: a single cell consists of a current collector plate, electrodes, an electrode frame, a diaphragm, an electrode frame, electrodes, a current collector plate, and seals between the current collector plate and electrode frame, and between the electrode frame and diaphragm. Multiple cells are connected in series using bipolar plates to form a stack. The stack is flanked by clamping plates with threaded holes. Springs on compression screws compress the stack to ensure electrode compression and stack sealing.

[0004] For liquid flow battery stacks, sealing is an important factor affecting stack performance and determining stack life. In recent years, various sealing methods have been tried on liquid flow battery stacks, from traditional rubber materials (wire seals, surface seals) to new hot melt welding, ultrasonic welding, and laser welding, all with the goal of improving the reliability of the sealing structure, reducing the difficulty of stack assembly, and extending the stack life. In addition, the sealing of liquid flow batteries also includes external seals and internal seals. The former determines whether the electrolyte will leak, while poor sealing of the latter will cause the positive and negative electrolytes to mix and cross-link, resulting in capacity decay and reduced efficiency. The diaphragm and bipolar plate are the key materials for isolating the positive and negative electrolytes in liquid flow batteries, and their airtightness largely determines the internal sealing of the stack. Therefore, the airtightness of the diaphragm, bipolar plate, and integrated components such as plate frame / bipolar plate, plate frame / diaphragm is of great significance to the internal sealing of the stack.

[0005] In order to ensure the performance and reliability of liquid flow batteries, key materials and components need to be tested for air tightness before the stack is assembled. However, the structure of common air tightness testing devices is relatively complex, the air tightness testing process is relatively cumbersome, the testing efficiency is low, and it is difficult to accurately detect the location of air leaks in materials and components.

[0006] Therefore, a new technology is needed to solve the problem in the prior art that the airtightness detection efficiency of the liquid flow battery is low and it is difficult to accurately detect the location where the leakage occurs. Utility Model Content

[0007] In order to solve the above problems in the prior art, the utility model provides an airtightness detection device for a liquid flow battery, which has a simple structure, is easy to detect and operate, can accurately detect the location of the leak, and has a high airtightness detection efficiency.

[0008] The utility model adopts the following technical solutions:

[0009] A device for detecting air tightness of a liquid flow battery comprises a tray, a pressure plate, a clamp, a seal and a gas pipeline, wherein the gas pipeline is provided with a pressure gauge and a valve, the upper end of the tray is provided with a ventilation groove, the bottom of the ventilation groove is provided with a ventilation hole connected to the gas pipeline, the pressure gauge is located between the tray and the valve, the bottom surface of the test piece can seal the notch of the ventilation groove to form a gas cavity in the ventilation groove, the bottom surface of the pressure plate can be tightly connected to the upper end of the test piece, a plurality of through holes connecting the upper end surface and the lower end surface of the pressure plate are provided on the pressure plate at intervals, and the clamp is used to clamp the tray and the pressure plate.

[0010] As a further improvement to the technical solution of the present invention, a reinforcing rib is horizontally provided in each of the through holes, and both ends of the reinforcing rib are fixedly connected to the inner wall of the through hole.

[0011] As a further improvement of the technical solution of the present invention, it also includes a first seal and a second seal. The first seal is located between the bottom surface of the workpiece to be tested and the tray, and is used to tightly connect the tray and the bottom surface of the workpiece to be tested. The first seal is located outside the notch of the vent groove; the second seal is located at the edge of the upper end surface of the workpiece to be tested, and is used to tightly connect the pressure plate and the workpiece to be tested. The second seal is located outside the multiple through holes.

[0012] As a further improvement of the technical solution of the present invention, a receiving groove for placing the test piece is provided above the tray, the ventilation groove is provided at the bottom of the receiving groove, and the first sealing member is located between the receiving groove and the battery component to be tested.

[0013] As a further improvement of the technical solution of the present invention, a plurality of positioning posts are protruded at intervals along the upper edge of the tray, and the positioning posts are parallel to each other. The pressure plate is provided with through holes corresponding to the positioning posts, and each through hole can allow the corresponding positioning post to pass through.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The flow battery airtightness testing device of this solution has a simple structure, is easy to operate, can accurately detect the location of leaks, and has high airtightness testing efficiency. It is applicable to airtightness testing of integrated components including diaphragms, bipolar plates, and plate-frame / bipolar plate, plate-frame / diaphragm, etc. It has high adaptability, a wide range of test objects, a simple testing method, and accurate test results, and is widely applicable in the field of flow battery manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The technology of the utility model is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0017] Figure 1 This is a schematic diagram of the connection structure of the tray, pressure plate and ventilation pipeline of the utility model;

[0018] Figure 2 It is a side view of the connection structure of the tray, the pressure plate and the ventilation pipeline of the utility model.

[0019] Reference numerals:

[0020] 1-tray; 11-accommodation groove; 12-venting groove; 13-venting hole; 14-air inlet hole; 15-positioning column; 16-bolt hole;

[0021] 2-pressure plate; 21-through hole; 22-reinforcement rib; 23-through hole;

[0022] 3-Gas pipeline; 31-Pressure gauge. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict. The same reference numerals used throughout the drawings indicate the same or similar parts.

[0024] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. In addition, the terms "upper," "lower," "left," and "right" used in this utility model are only used with respect to the relative positions of the components of the utility model in the accompanying drawings.

[0025] Reference Figures 1 to 2 A device for detecting the air tightness of a liquid flow battery comprises a tray 1, a pressure plate 2, a fixture, a seal and a gas pipeline 3, wherein the gas pipeline 3 is provided with a pressure gauge 31 and a valve. The tray 1 can be made of engineering plastics such as PP and PVC, or metals such as aluminum alloy and carbon steel. A vent groove 12 is provided at the upper end of the tray 1, and a vent hole 13 connected to the gas pipeline 3 is provided at the bottom of the vent groove 12. The pressure gauge 31 is located between the tray 1 and the valve. The bottom surface or one side surface of the test piece can seal the notch of the vent groove 12 to form a gas cavity in the vent groove 12. The pressure plate 2 can be made of engineering plastics such as PP and PVC, or metals such as aluminum alloy and carbon steel. The bottom surface of the pressure plate 2 can be tightly connected to the upper end of the test piece. A number of through holes 21 connecting the upper end surface and the lower end surface of the pressure plate 2 are provided on the pressure plate 2 at intervals. The fixture is used to clamp the tray 1 and the pressure plate 2. There are multiple bolt holes 16 around the tray 1 for fastening the tray 1 and the pressure plate 2. One or more interconnected gas cavities can be set in the tray 1, and one side of the test piece forms part of the inner wall of the gas cavity, and the gas introduced into the gas cavity directly contacts the test piece. If there is a leak in the liquid flow battery test piece, such as a diaphragm, a bipolar plate, and an integrated component such as a plate frame / bipolar plate, a plate frame / diaphragm, the gas in the gas cavity can pass through the leaking part inside the test piece and leak out from its upper end face, so that it can be observed whether there is a leak in the test piece, and the leaking part can be confirmed by observing the position of the through hole where the leak occurs. Among them, one or more air inlet and outlet holes can be set on one side of the tray 1, which can connect the gas pipeline 3 and the gas cavity for ventilating the gas cavity. When only one or several air inlet holes 14 are needed, the other air inlet holes 14 can be blocked. When one air inlet hole 14 is set on the tray, it can be referred to Figure 1 and 2 Soap water or soap bubbles can be sprayed on the through holes 21 of the pressure plate 2, and the position of the leak of the test piece can be locked by the position of the bubble or bubble burst, which is convenient for observation and judgment of the leak position. Other methods that can observe gas leakage in each through hole can also be used to confirm the occurrence of the leak phenomenon.

[0026] The flow battery airtightness testing device of this solution clamps the test piece between a tray 1 and a pressure plate 2, bringing the test piece into contact with the air within the gas cavity. Leakage locations are observed through a number of through-holes 21 provided on the pressure plate 2. This simple structure facilitates testing operations, improves airtightness testing efficiency, and can precisely detect leaks. It is applicable to airtightness testing of integrated components, including diaphragms, bipolar plates, and plate-frame / bipolar plate / plate, or plate-frame / diaphragm, offering high adaptability and wide scope of testing.

[0027] Specifically, the fixture can preferably be a bolt, a bolt spring, or a hydraulic device. When the fixture is a bolt, the pressing force of the pallet 1 and the pressure plate 2 on the workpiece to be tested can be adjusted by loosening or tightening the bolt fastener. When the fixture is a hydraulic device, the pressing force of the pallet 1 and the pressure plate 2 on the workpiece to be tested can be adjusted by the hydraulic pressure.

[0028] Specifically, the outside of the tray 1 is provided with an air inlet 14 connected to the vent 13. A gas line 3 connects a gas generator, such as an air compressor, to the gas cavity within the tray 1 through the air inlet 14 on the tray 1, facilitating ventilation and pressurization of the test piece. A pressure gauge 31 installed on the gas line 3 monitors the pressure in the gas cavity, and a valve is used to ventilate or release air.

[0029] Specifically, each of the through holes 21 is provided with a horizontal reinforcing rib 22, and both ends of the reinforcing rib 22 are fixedly connected to the inner wall of the through hole 21. The provision of the reinforcing rib 22 in the through hole 21 can strengthen the structural strength and rigidity of the tooling pressure plate 2, making it easier to observe the sealing effect. There are multiple bolt holes 16 around the pressure plate 2, which are used to fasten the tray 1 and the pressure plate 2. When performing a sealing test on the workpiece to be tested, if there is air leakage in the workpiece to be tested, the specific location of the air leakage can be locked by the reinforcing ribs 22 of the through holes 21 at different positions of the pressure plate 2. The size of the through hole 21 can be designed to meet the requirements of the structural strength and rigidity of the tooling pressure plate 2. The cross-sectional shape of the through hole 21 can be a polygonal structure such as a triangle, a quadrilateral, or a pentagon.

[0030] Specifically, the air tightness detection device of the liquid flow battery of this scheme also includes a first seal and a second seal. The first seal is located between the bottom surface of the test piece and the tray 1, and is used to tightly connect the tray 1 and the bottom surface of the test piece to be tested, which can avoid air leakage between the bottom surface of the test piece and the tray 1. The first seal is located on the outside of the notch of the ventilation groove 12 and can be arranged around the outside of the notch of the ventilation groove 12. It will not affect the area of ​​the bottom surface of the test piece that needs to be detected for air leakage. The size of the first seal can be selected according to actual conditions. The first seal can be set at the edge of the bottom surface of the test piece or near the edge of the area of ​​the bottom surface of the test piece that needs to be detected for air leakage. The second seal, located at the edge of the upper end face of the test piece, tightly connects the pressure plate 2 to the test piece, preventing gas from escaping from the gas cavity through the leaking area of ​​the test piece and escaping between the upper end face edge of the test piece and the pressure plate 2. The projections of the through holes 21 are all located within the projection area of ​​the notch of the vent groove 12. The second seal is located outside these through holes 21, and the second seal surrounds the outside of the area where all through holes 21 are located. If the upper end face of the test piece is small, a second seal of appropriate size can be selected to fit the upper end face edge of the test piece.

[0031] Specifically, a receiving groove 11 for placing the test piece is provided above the tray 1, and the ventilation groove 12 is provided at the bottom of the receiving groove 11. The first sealing member is located between the receiving groove 11 and the battery component to be tested. A pressing groove opposite to the receiving groove 11 on the tray 1 is provided on the lower side of the pressure plate 2. The upper end of the test piece can be accommodated in the pressing groove, and several through holes 21 can be connected to the pressing groove. The second sealing member is located between the bottom of the pressing groove and the upper end of the test piece.

[0032] Specifically, the first and second seals are preferably made of rubber such as FKM, EPDM, or RTV. They may preferably be constructed as sealing lines or gaskets. The first and second seals are used to seal the interface between the tray 1, the platen 2, and the test piece. The first and second seals between the tray 1 and the platen 2 may be a single seal or a combination of multiple seals.

[0033] Specifically, a component with the same size as the notch of the vent groove 12 of the tray 1 can be set in the pressing groove of the pressure plate 2. The component has a large porosity and good compressibility, which can ensure uniform force on the test piece during the airtightness test; the component can preferably be one of carbon felt, graphite felt, carbon cloth, carbon paper, or a composite of multiple types.

[0034] Specifically, a plurality of positioning posts 15 are protruded at intervals along the upper edge of the tray 1 , and the positioning posts 15 are parallel to each other. The pressure plate 2 is provided with through holes 23 corresponding to the positioning posts 15 , and each through hole 23 can allow the corresponding positioning post 15 to pass through.

[0035] A method for detecting the air tightness of a flow battery component, using the air tightness detection device for a flow battery as described above, comprises the following steps:

[0036] S1. Place the test piece between tray 1 and pressure plate 2.

[0037] S2. Separate the two sides of the test piece with a first seal and a second seal respectively, and fix the tray 1 and the pressure plate 2 with a clamp. A conventional clamp can be used to clamp the tray 1 and the pressure plate 2 together to clamp the test piece.

[0038] S3. Under test conditions with an ambient temperature of 25°C ± 1°C, ventilate and pressurize the gas cavity between tray 1 and the test piece through gas line 3. The test gas should be dry, clean air, nitrogen, or other inert gas.

[0039] During ventilation, after a period of time, the gas pressure in the gas cavity becomes high, and at this time, ventilation is stopped.

[0040] During the pressurization process, wait for the compressed gas in the gas cavity to stop fluctuating and reach a stable state before maintaining the pressure. In the stable state after the pressure maintenance is completed, the gas pressure in the gas cavity remains stable, and the gas pressure at this time is recorded as P1.

[0041] S4. Observe the value on pressure gauge 31. When the set pressure is reached, close the valve and observe the change in gas pressure over time. Perform a leak test. During the set test time, the gas in the gas cavity will continue to leak due to a loose seal. After the set time, record the gas pressure leakage value ΔP. Depending on different test requirements, the preset time can range from several minutes to several tens of minutes.

[0042] S5. After adjusting the set pressure, re-measure the change in gas pressure within the gas cavity. Because the sealing performance of the test piece varies under different pressures, the pressure applied to the test piece can be adjusted and then steps S3 and S4 can be repeated to re-measure the change in gas pressure within the gas cavity.

[0043] S6. Determine whether the test piece meets the sealing requirements based on the changes in gas pressure.

[0044] To determine whether the DUT meets the sealing requirements, the test results can be used to determine airtightness. If the gas pressure P1 is less than the set lower limit of inflation pressure, it indicates that the gas pressure requirement cannot be met during inflation and the DUT is leaking. If the gas pressure leakage value ΔP is greater than the set upper limit of leakage, the sealing performance of the DUT component cannot meet the requirements. If the gas pressure P1 is greater than the set lower limit of inflation pressure and the gas pressure leakage value ΔP is less than the set upper limit of leakage, the DUT's airtightness meets the requirements.

[0045] Example 1

[0046] In this embodiment, the graphite bipolar plate is placed between the tray 1 and the pressure plate 2, and the upper and lower contact surfaces of the graphite bipolar plate are separated by sealing gaskets and fixed with a clamp. The fastening force applied by the clamp is 0.5-10T. The gas cavity between the tray 1 and the graphite bipolar plate is then ventilated and pressurized through the gas pipeline 3. The gas pressure introduced is 10-200kPa. After reaching the set pressure, the valve is closed, the seal is maintained and the pressure is maintained for 0.1-2 hours. The change of gas pressure over time is then observed through the pressure gauge 31. If there is no obvious change in air pressure, it is considered that the air tightness is good and meets the requirements.

[0047] Example 2

[0048] In this embodiment, the test piece is different from that in Example 1. The diaphragm is placed between the tray 1 and the pressure plate 2, and the upper and lower contact surfaces of the diaphragm are separated by sealing gaskets and fixed with a clamp. The tightening force applied by the clamp is 0.5-10T. The gas cavity between the tray 1 and the diaphragm is then ventilated and pressurized through the gas pipeline 3. The gas pressure introduced is 10-200kPa. After reaching the set pressure, the valve is closed, the seal is maintained under pressure and it is left to stand for 0.1-2 hours. The change of gas pressure over time is then observed through the pressure gauge 31. If there is no obvious change in air pressure, it is considered that the air tightness is good and meets the requirements.

[0049] Example 3

[0050] In this embodiment, the test piece is different from that in embodiment 1 and embodiment 2. The laser welded plate frame / bipolar plate is placed between the tray 1 and the pressure plate 2, and the upper and lower contact surfaces of the laser welded plate frame / bipolar plate are separated by sealing gaskets and fixed with a clamp. The clamp exerts a fastening force of 0.5-10T. Then, the gas cavity between the tray 1 and the laser welded plate frame / bipolar plate is ventilated and pressurized through the gas pipeline 3. The gas pressure introduced is 10-200kPa. After reaching the set pressure, Close the valve, seal and maintain pressure for 0.1-2 hours, then observe the change of gas pressure over time through the pressure gauge 31; if the air pressure drops below 30kPa within 20 minutes, it can be determined that the air tightness of the test piece does not meet the requirements; at the same time, spray soapy water or soap bubbles on each through hole 21 of the pressure plate 2, such as spraying soapy water or soap bubbles on the reinforcement rib 22 area of ​​each through hole 21, so as to locate the leaking position of the test piece by the position where the bubbles are generated or the bubbles burst, so as to facilitate observation and judgment of the leaking position.

[0051] For other details of the air tightness detection device for a liquid flow battery described in the present invention, please refer to the prior art and will not be described in detail here.

[0052] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A device for detecting the air tightness of a flow battery, characterized in that: It includes a tray, a pressure plate, a clamp, a seal and a gas pipeline. The gas pipeline is provided with a pressure gauge and a valve. The upper end of the tray is provided with a ventilation groove. The bottom of the ventilation groove is provided with a ventilation hole connected to the gas pipeline. The pressure gauge is located between the tray and the valve. The bottom surface of the test piece can seal the notch of the ventilation groove to form a gas cavity in the ventilation groove. The bottom surface of the pressure plate can be tightly connected to the upper end of the test piece. A number of through holes connecting the upper end surface and the lower end surface of the pressure plate are provided on the pressure plate at intervals. The clamp is used to clamp the tray and the pressure plate.

2. The airtightness detection device for a flow battery according to claim 1, characterized in that: A reinforcing rib is horizontally provided in each through hole, and both ends of the reinforcing rib are fixedly connected to the inner wall of the through hole.

3. The airtightness detection device for a flow battery according to claim 1, characterized in that: It also includes a first seal and a second seal, the first seal is located between the bottom surface of the workpiece to be tested and the tray, and is used to tightly connect the tray and the bottom surface of the workpiece to be tested, and the first seal is located outside the notch of the vent groove; the second seal is located at the edge of the upper end surface of the workpiece to be tested, and is used to tightly connect the pressure plate and the workpiece to be tested, and the second seal is located outside the plurality of through holes.

4. The airtightness detection device for a flow battery according to claim 3, characterized in that: A receiving groove for placing the test piece is provided above the tray, the ventilation groove is provided at the bottom of the receiving groove, and the first sealing member is located between the receiving groove and the battery component to be tested.

5. The airtightness detection device for a flow battery according to claim 1, characterized in that: A plurality of positioning posts are protruded at intervals along the upper edge of the tray, and the positioning posts are parallel to each other. The pressure plate is provided with through holes corresponding to the positioning posts, and each through hole can allow the corresponding positioning post to pass through.

Images