A method of repairing a fuel cell graphite bipolar plate

Abstract

The application provides a fuel cell graphite bipolar plate repairing method and belongs to the technical field of fuel cells. The method solves the technical problems of short service life of the existing fuel cell graphite bipolar plate and the absence of reliable repairing method. The fuel cell graphite bipolar plate repairing method comprises the following steps: a, false stack assembly; b, sealing test; c, air exhaust; d, waterway operation; e, air operation; f, repairing and air drying; after repeating steps d and e for 2-3 times, the false stack is disassembled, the fuel cell graphite bipolar plate to be repaired is opened with a tool and naturally air dried for 24-48 hours, and the repairing is completed. The application has the advantages of greatly improving the service life of the fuel cell graphite bipolar plate and stable and reliable repairing.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology and relates to a repair method, particularly a repair method for graphite bipolar plates in fuel cells. Background Technology

[0002] With the booming development of hydrogen energy projects, the application scenarios of hydrogen fuel cells are constantly expanding, and industrialization is accelerating. One of the main components of hydrogen fuel cells, the bipolar plate, is currently divided into two types: metal bipolar plates and graphite bipolar plates. Graphite bipolar plates will experience cross-leakage after a certain period of operation, ultimately affecting the lifespan of the fuel cell. This is caused by the gradual detachment of epoxy resin that settles during the production process of graphite bipolar plates.

[0003] A search revealed no patents currently disclosing a method for repairing graphite bipolar plates in fuel cells. Therefore, to address the aforementioned issues, a method for repairing graphite bipolar plates in fuel cells is proposed. This method utilizes the principle of re-immersion to repair graphite bipolar plates with micro-leakage or cross-contamination, allowing them to continue to be used and significantly extending their service life. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a repair method for graphite bipolar plates in fuel cells, thereby solving the problem of short service life of existing graphite bipolar plates in fuel cells.

[0005] The objective of this invention can be achieved through the following technical solution: a method for repairing graphite bipolar plates in fuel cells, characterized by comprising the following steps:

[0006] a. Dummy stack assembly: The graphite bipolar plates of the fuel cell to be repaired are installed in the bipolar plate repair device and assembled into a dummy stack according to the stacking requirements. The electrodes used are dummy electrodes, and the two end plates are also special end plates designed for the dummy stack, realizing three-in-three-out air, water and hydrogen.

[0007] b. Sealing test: Test the sealing of pipelines and components, and complete the installation after checking the seal to ensure there is no leakage;

[0008] c. Air purging: Add epoxy resin for repair to the water tank of the bipolar plate repair device, and adjust the switching switch one and the air purging valve to purge the air from the dummy stack, pipeline one and pipeline two.

[0009] d. Water circuit operation: Adjust the switch to enter the water circuit operation mode, adjust the water circuit pressure, and start operation. The operation time is 5-10 minutes.

[0010] e. Air operation: the air inlet is adjusted to the inlet pressure, the air temperature is controlled between 60-90 DEG C, the switching switch two is adjusted to enter the air operation mode, the operation is started, and the operation time is 5-10 min;

[0011] f. Repairing and drying: after repeating steps d and e for 2-3 times, the false stack is disassembled, the graphite bipolar plate to be repaired is opened with a tool, and is naturally dried for 24-48 hours, and the repairing is completed.

[0012] Compared with manual repairing, the above process is more efficient, and the quality of the repairing is more stable.

[0013] The bipolar plate repairing device comprises a water tank, a water pump, an air heating tank and a false stack, the water inlet of the water pump is connected with the water tank, the water outlet of the water pump is connected with the false stack through a water route pressure gauge, the false stack is connected with the water tank return pipe through a pipe two, the water tank return pipe is connected with the water tank, and the false stack is connected with the outlet of the air heating tank through an air pressure gauge.

[0014] The false stack is made according to the size of the normal electrode, has a sealing and flow guiding effect, adopts a false battery as the electrode, and can accommodate a plurality of graphite bipolar plates to be repaired.

[0015] According to the above structure, the false stack is installed according to the installation method of the normal electrode, and the difference from the normal electrode is that the electrode is a false battery, is made according to the size of the normal electrode, can have a sealing and flow guiding effect, and the end plate has hydrogen, water and empty ports, and does not need an insulating plate, a current collecting plate and the like, and is much simpler than the normal electrode.

[0016] The switching switch is arranged between the water route pressure gauge and the air pressure gauge.

[0017] According to the above structure, the switching switch can be used for switching the flow direction of the pipe, so that the water route and the air route flow according to the designed direction.

[0018] The air heating tank is electrically connected with the temperature control box through an electric wire one.

[0019] According to the above structure, the temperature control box is arranged for adjusting the temperature of the inlet air, and is used for adjusting the air temperature of the inlet stack.

[0020] The water outlet of the water pump is also connected with the false stack through a pipe one, and the pipe one is provided with a switching switch one and an air exhaust valve.

[0021] The water pump is electrically connected with a water pump frequency converter through an electric wire two, and the water pump frequency converter is used for adjusting the rotating speed of the water pump, so that the water route reaches the set pressure.

[0022] A liquid level visible window is arranged on the water tank.

[0023] With the above structure, the liquid level visible window is used for observing the liquid level in the water tank, ensuring sufficient water in the water tank and supplementing at any time.

[0024] The liquid level visible window adopts a transparent PVC pipe, and the upper and lower parts of the transparent PVC pipe are communicated with the water tank.

[0025] The water tank is provided with a water tank inlet for adding water.

[0026] The water pump and the water route pressure gauge adopt stainless steel materials, and have the effects of high-temperature resistance, corrosion resistance and no ion precipitation during use.

[0027] The working principle of the present application is as follows: after the epoxy resin is added into the water tank for circulation, the excess epoxy resin is blown out by hot air, and the curing is accelerated, so that the sealing effect is restored; by using the principle of re-dipping, the graphite bipolar plate with micro-leakage and gas leakage is repaired, the repair of the fuel cell graphite bipolar plate is completed, and the graphite bipolar plate can continue to be used, so that the service life of the graphite bipolar plate is greatly prolonged.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] 1. The problem of short service life of the existing fuel cell graphite bipolar plate is solved, and the service life of the fuel cell graphite bipolar plate is greatly improved.

[0030] 2. Compared with manual repair, it is more efficient, and the quality of repair is more stable. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is the process flow chart of the present application.

[0032] Figure 2 is the plane structure schematic diagram of the present application.

[0033] Figure 3 is the three-dimensional structure schematic diagram of the present application.

[0034] Figure 4 is the three-dimensional structure schematic diagram of another view of the present application.

[0035] Figure 5 is the plane structure schematic diagram of another view of the present application.

[0036] In the figure, 1, liquid level visible window; 2, water tank; 3, water pump frequency converter; 4, water tank loop pipe; 5, air exhaust valve; 6, switch one; 7, pipe one; 8, dummy stack; 9, pipe two; 10, water pressure gauge; 11, air pressure gauge; 12, switch two; 13, temperature control box; 14, wire one; 15, air heating tank outlet; 16, air heating tank; 17, water tank inlet; 18, hydrogen inlet and outlet; 19, water inlet and outlet; 20, air inlet and outlet; 24, wire two; 25, water pump; 26, air inlet; 27, switch three. DETAILED DESCRIPTION

[0037] The following is a specific embodiment of the present application and further describes the technical solutions of the present application in conjunction with the drawings, but the present application is not limited to these embodiments.

[0038] As shown in the figure, a method for repairing a fuel cell graphite bipolar plate, in this embodiment, comprising the following steps: Figures 1-5

[0039] a. Dummy stack assembly: install the fuel cell graphite bipolar plate to be repaired in the bipolar plate repair device, assemble to form a dummy stack 8 according to the requirements of the stack, the electrode used is a dummy electrode, and the two-end plate is also a special end plate designed for the dummy stack to realize three-in and three-out of air, water and hydrogen; in this embodiment, dummy stack assembly is adopted, which significantly reduces the cost and is simple to assemble;

[0040] b. Sealing test: test the sealing of the pipeline and components, and install after checking that there is no leakage;

[0041] c. Air exhaust: add special epoxy resin for repair in the water tank 2 of the bipolar plate repair device, adjust the switch one 6 and the air exhaust valve 5, and exhaust the air in the dummy stack 8, the pipe one 7 and the pipe two 9;

[0042] d. Water circuit operation: adjust the switch two 12 to enter the water circuit operation mode, adjust the water circuit pressure, start operation, and the operation time is 5-10 min;

[0043] e. Air operation: adjust the air inlet 26 to the inlet pressure, control the air temperature between 60-90℃, adjust the switch two 12 to enter the air operation mode, start operation, and the operation time is 5-10 min;

[0044] f. Repair and air dry: after repeating steps d and e for 2-3 times, disassemble the dummy stack 8, and air dry the fuel cell graphite bipolar plate to be repaired with a tool for 24-48 hours, and the repair is completed; in this embodiment, the tool is a fuel cell graphite bipolar plate special tool.

[0045] ​Compared with manual repair, the above process is more efficient, and the repaired quality is more stable.

[0046] As shown in Figures 2-5 The bipolar plate repair device includes a water tank 2, a water pump 25, an air heating tank 16, and a false electric pile 8. The water inlet of the water pump 25 is connected with the water tank 2. The water outlet of the water pump 25 is connected with the false electric pile 8 through a water circuit pressure gauge 10. The false electric pile 8 is connected with a water tank circuit pipe 4 through a pipe 9. The water tank circuit pipe 4 is connected with the water tank 2. The false electric pile 8 is connected with an air heating tank outlet 15 through an air pressure gauge 11.

[0047] The false electric pile 8 is made according to the size of a normal electrode and has a sealing and flow guiding effect. The electrode is a false battery. The false electric pile 8 can accommodate a plurality of graphite bipolar plates to be repaired.

[0048] With the above structure, the false electric pile 8 installs the graphite bipolar plates to be repaired according to the installation method of a normal electric pile. The difference from the normal electric pile is that the electrode is a false battery, which is made according to the size of a normal electrode and can have a sealing and flow guiding effect. The end plate has hydrogen, water, and empty ports, and does not need an insulating plate and a current collecting plate, which is much simpler than the normal electric pile.

[0049] A switch is arranged between the water circuit pressure gauge 10 and the air pressure gauge 11.

[0050] With the above structure, the switch can be used to switch the flow direction of the pipe, so that the water circuit and the air circuit flow according to the designed direction.

[0051] The air heating tank 16 is electrically connected with a temperature control tank 13 through an electric wire 14.

[0052] With the above structure, the temperature control tank 13 is configured to adjust the temperature of the incoming air and is used to adjust the temperature of the air entering the electric pile.

[0053] The water outlet of the water pump 25 is also connected with the false electric pile 8 through a pipe 7. The pipe 7 is provided with a switch 6 and an air exhaust valve 5.

[0054] The water pump 25 is electrically connected with a water pump frequency converter 3 through an electric wire 24. The water pump frequency converter 3 is used to adjust the rotating speed of the water pump 25, so that the water circuit reaches a set pressure.

[0055] A liquid level visible window 1 is arranged on the water tank 2.

[0056] With the above structure, the liquid level visible window 1 is used to observe the liquid level in the water tank 2, so as to ensure that the water in the water tank 2 is sufficient and can be supplemented at any time.

[0057] The liquid level visible window 1 is made of a transparent PVC pipe. The upper part and the lower part of the transparent PVC pipe are connected with the water tank 2.

[0058] A water tank inlet 17 for adding water is formed on the water tank 2.

[0059] The water pump 25 and the water route pressure gauge 10 are made of stainless steel, and have the effects of high temperature resistance, corrosion resistance and no ion precipitation during use.

[0060] The working principle of the application is as follows: after the epoxy resin is added into the water tank 2 for circulation, the excess epoxy resin is blown out by hot air to accelerate curing, thereby achieving the effect of restoring sealing; by using the principle of re-dipping, the graphite bipolar plate with micro-leakage and gas leakage is repaired, the repair of the graphite bipolar plate of the fuel cell is completed, the graphite bipolar plate can continue to be used, and the service life of the graphite bipolar plate is greatly prolonged.

[0061] The specific embodiments described herein are merely illustrative of the spirit of the application. Those skilled in the art of the application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, without departing from the spirit of the application or exceeding the scope defined by the appended claims.

Claims

1. A method of repairing a fuel cell graphite bipolar plate, characterized by, It comprises the following steps: a. False stack assembly: install the fuel cell graphite bipolar plate to be repaired in the bipolar plate repair device, assemble to form a false stack (8) according to the requirements of the stack, the electrode used is a false electrode, and the two-end plate is a special end plate designed for the false stack, realizing three-in and three-out of air, water and hydrogen; b. Sealing test: test the sealing of the pipeline and components, and check for leaks to ensure that the installation is complete; c. Air exhaust: add a special epoxy resin for repair in the water tank (2) of the bipolar plate repair device, adjust the switching switch one (6) and the air exhaust valve (5), and exhaust the air in the false stack (8), pipeline one (7) and pipeline two (9); d. Waterway operation: adjust the switching switch two (12) to enter the waterway operation mode, adjust the waterway pressure, start operation, and the operation time is 5-10 min; e. Air operation: adjust the air inlet (26) to the inlet pressure, control the air temperature between 60-90℃, adjust the switching switch two (12) to enter the air operation mode, start operation, and the operation time is 5-10 min; f. Repair and drying: after repeating steps d and e for 2-3 times, disassemble the false stack (8), dry the fuel cell graphite bipolar plate to be repaired with the tooling, and naturally dry for 24-48 hours to complete the repair.

2. The method of repairing a fuel cell graphite bipolar plate according to claim 1, wherein The bipolar plate repair device comprises a water tank (2), a water pump (25), an air heating tank (16) and a false stack (8), the water inlet of the water pump (25) is connected with the water tank (2), the water outlet of the water pump (25) is connected with the false stack (8) through a waterway pressure gauge (10), the false stack (8) is connected with the water tank return pipe (4) through a pipeline two (9), the water tank return pipe (4) is connected with the water tank (2), and the false stack (8) is connected with the air heating tank outlet (15) through an air pressure gauge (11).

3. The method of repairing a fuel cell graphite bipolar plate according to claim 1, wherein The false stack (8) is made according to the size of the normal electrode, has a sealing and flow guiding effect, uses an electrode as a false battery, and the false stack (8) can accommodate a plurality of graphite bipolar plates to be repaired.

4. The method of repairing a fuel cell graphite bipolar plate according to claim 2, wherein Switching switches are arranged between the waterway pressure gauge (10) and the air pressure gauge (11).

5. The method of repairing a fuel cell graphite bipolar plate according to claim 2, wherein The air heating tank (16) is electrically connected with a temperature control tank (13) through an electric wire one (14).

6. The method of repairing a fuel cell graphite bipolar plate according to claim 2, wherein The water outlet of the water pump (25) is also connected with the false stack (8) through a pipeline one (7), and the pipeline one (7) is provided with a switching switch one (6) and an air exhaust valve (5).

7. The method of repairing a fuel cell graphite bipolar plate of claim 2, wherein The water pump (25) is electrically connected with a water pump frequency converter (3) through an electric wire two (24), and the water pump frequency converter (3) is used to adjust the rotating speed of the water pump (25) to make the waterway reach the set pressure.

8. The method of repairing a fuel cell graphite bipolar plate according to claim 1, wherein A liquid level visible window (1) is arranged on the water tank (2), and the liquid level visible window (1) adopts a transparent PVC pipe, and the upper and lower parts of the transparent PVC pipe are connected with the water tank (2).

9. The method of repairing a fuel cell graphite bipolar plate according to claim 1, wherein A water tank inlet (17) for adding water is arranged on the water tank (2).

10. The method of repairing a fuel cell graphite bipolar plate of claim 2, wherein, The water pump (25) and the waterway pressure gauge (10) are made of stainless steel, and have the effects of high temperature resistance, corrosion resistance and no ion precipitation during use.

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