Fuel cell bipolar plate

Abstract

The present invention relates to the field of fuel cell technology, and in particular to a fuel cell bipolar plate, including a hydrogen plate and an oxygen plate, wherein the hydrogen plate is provided with a hydrogen flow channel, and the oxygen plate is provided with an air flow channel, and the air inlet ends of the hydrogen flow channel and the air flow channel are provided with a hydrogen inlet, an air inlet and a coolant inlet, and the air outlet ends of the hydrogen flow channel and the air flow channel are provided with a hydrogen outlet, an air outlet and a coolant outlet, and the cross-sectional area of ​​the hydrogen inlet is larger than the cross-sectional area of ​​the hydrogen outlet, and the cross-sectional area of ​​the air inlet is smaller than the cross-sectional area of ​​the air outlet. On the one hand, it is beneficial to increase the flow rate and facilitate the accelerated discharge of water generated after the reaction; on the second hand, it avoids the air outlet flow rate being too fast and improves the conversion efficiency of air and hydrogen; on the third hand, it avoids the problem of excessive pressure difference between hydrogen and air at the air outlet and improves the life of the fuel cell stack.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a bipolar plate for a fuel cell. Background Art

[0002] A fuel cell is an electrochemical reaction device that can convert chemical energy into electrical energy. It has the advantages of high energy conversion efficiency, zero emissions, and no mechanical noise, and is highly favored in military and civilian fields. Proton exchange membrane fuel cells (PEMFC) use solid polymer membranes as electrolytes, and have advantages such as simple structure and low operating temperature. They have unique advantages as mobile power sources. Toyota Motor Corporation of Japan, Hyundai Motor Company of South Korea and other internationally renowned automobile companies have developed mass-produced fuel cell electric vehicles (FCEV or FCV) powered by PEMFC.

[0003] Each PEMFC cell consists of two plates (a hydrogen plate and an oxygen plate) and a membrane electrode sandwiched between the two plates. The hydrogen plate of the PEMFC is provided with a fuel flow channel, which is a place where the fuel flows and is transported, and the fuel is transported to the anode catalyst through it. The oxygen plate of the PEMFC is provided with an oxidant flow channel, which is a place where the oxidant (oxygen or air) flows and is transported, and the oxidant reaches the cathode catalyst through it. With the help of the fuel flow channel and the oxidant flow channel, the fuel and the oxidant can be continuously transported to the fuel cell so that the fuel cell can continuously output electrical energy.

[0004] In the current technology, in the stage of fuel cell industrialization, the conversion efficiency needs to be further improved, and extending the service life and reducing costs have become many urgent problems that need to be solved. The research and development and production of fuel cells gather cutting-edge technologies from multiple disciplines and fields. Any improvement in conversion efficiency, service life and cost reduction has great economic value and social benefits. Summary of the invention

[0005] The object of the present invention is to provide a fuel cell bipolar plate that helps to improve the fuel cell conversion efficiency, working stability and stack life.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a fuel cell bipolar plate, including a hydrogen electrode plate and an oxygen electrode plate, wherein the hydrogen electrode plate is provided with a hydrogen flow channel, and the oxygen electrode plate is provided with an air flow channel, the air inlet ends of the hydrogen flow channel and the air flow channel are provided with a hydrogen inlet, an air inlet and a coolant inlet, and the air outlet ends of the hydrogen flow channel and the air flow channel are provided with a hydrogen outlet, an air outlet and a coolant outlet, the cross-sectional area of ​​the hydrogen inlet is larger than the cross-sectional area of ​​the hydrogen outlet, and the cross-sectional area of ​​the air inlet is smaller than the cross-sectional area of ​​the air outlet.

[0007] Optionally, the hydrogen flow channel and the air flow channel both include an air inlet distribution area, a reaction area and an air outlet distribution area, and the reaction area is provided with a plurality of grooves formed by a plurality of reaction ridges arranged in parallel.

[0008] Optionally, both the inlet distribution area and the outlet distribution area of ​​the hydrogen flow channel are provided with distribution islands and hydrogen guide ridges, the hydrogen guide ridges are connected to the reaction ridges, and the distribution islands are evenly arranged at the inlet end of the hydrogen guide ridges.

[0009] Optionally, the distribution island is a cylinder.

[0010] Optionally, the air inlet distribution area and the air outlet distribution area of ​​the air flow channel are provided with air guide ridges, and the air guide ridges extend from the reaction area to the middle of the air inlet end of the air inlet distribution area and the middle of the air outlet end of the air outlet distribution area respectively.

[0011] Optionally, the depths of the gas inlet distribution zone and the gas outlet distribution zone are 0.03-0.07 mm greater than the depth of the reaction zone.

[0012] Optionally, both the hydrogen plate and the oxygen plate are provided with inspection ports.

[0013] Optionally, both the hydrogen electrode plate and the oxygen electrode plate are provided with positioning holes.

[0014] Optionally, the air inlet is arranged between the hydrogen inlet and the coolant inlet, and the air outlet is arranged between the hydrogen outlet and the coolant outlet.

[0015] Optionally, the hydrogen electrode plate and the oxygen electrode plate are both provided with sealing grooves, and the sealing grooves are arranged along the periphery of the hydrogen flow channel, the air flow channel, the hydrogen inlet, the air inlet and the coolant inlet.

[0016] The implementation of the embodiments of the present invention has the following technical effects:

[0017] On the one hand, the cross-sectional area of ​​the hydrogen inlet of the present invention is larger than the cross-sectional area of ​​the hydrogen outlet, thereby reducing the flow rate of hydrogen at the hydrogen outlet, which is beneficial to increase the flow rate and facilitate the accelerated discharge of water produced after the reaction; on the second hand, the cross-sectional area of ​​the air inlet is smaller than the cross-sectional area of ​​the air outlet. Since the pressure difference between the inlet and outlet on the air side is large, the pressure at the air outlet decreases and the volume increases. Therefore, excessive air flow rate is avoided by increasing the air outlet area; on the third hand, the air inlet and hydrogen inlet of the hydrogen plate and the oxygen plate are arranged on the same side, avoiding the problem of excessive pressure difference between hydrogen and air at the air outlet, thereby improving the life of the fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the hydrogen plate of a preferred embodiment of the present invention;

[0019] Figure 2 yes Figure 1The enlarged schematic diagram of point A in the middle;

[0020] Figure 3 is a longitudinal partial cross-sectional view of a hydrogen plate of a preferred embodiment of the present invention;

[0021] Figure 4 It is a structural schematic diagram of the oxygen electrode plate of a preferred embodiment of the present invention;

[0022] Figure 5 yes Figure 4 The enlarged schematic diagram of point B in the middle;

[0023] Figure 6 It is a longitudinal partial cross-sectional view of the oxygen electrode plate of the preferred embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 1. Hydrogen plate, 2. Oxygen plate, 3. Hydrogen flow channel, 4. Air flow channel, 5. Hydrogen inlet, 6. Air inlet, 7. Coolant inlet, 8. Hydrogen outlet, 9. Air outlet, 10. Coolant outlet, 11. Air inlet distribution area, 12. Reaction area, 13. Air outlet distribution area, 14. Distribution island, 15. Hydrogen guide ridge, 16. Air guide ridge, 17. Inspection port, 18. Positioning hole, 19. Sealing groove, 20. Reaction ridge. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by terms such as “longitudinal” and “horizontal” are 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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] refer to Figure 1 - Figure 6The present embodiment provides a fuel cell bipolar plate, including a hydrogen electrode plate 1 and an oxygen electrode plate 2, the hydrogen electrode plate 1 is provided with a hydrogen flow channel 3, the oxygen electrode plate 2 is provided with an air flow channel 4, the air inlet ends of the hydrogen flow channel 3 and the air flow channel 4 are provided with a hydrogen inlet 5, an air inlet 6 and a coolant inlet 7, the air outlet ends of the hydrogen flow channel 3 and the air flow channel 4 are provided with a hydrogen outlet 8, an air outlet 9 and a coolant outlet 10, the cross-sectional area of ​​the hydrogen inlet 5 is larger than the cross-sectional area of ​​the hydrogen outlet 8, and the cross-sectional area of ​​the air inlet 6 is smaller than the cross-sectional area of ​​the air outlet 9. On the one hand, the cross-sectional area of ​​the hydrogen inlet 5 of the present invention is larger than the cross-sectional area of ​​the hydrogen outlet 8, thereby reducing the flow rate of hydrogen at the hydrogen outlet 8, which is beneficial to increase the flow rate and facilitate the accelerated discharge of water produced after the reaction; on the second hand, the cross-sectional area of ​​the air inlet 6 is smaller than the cross-sectional area of ​​the air outlet 9. Since the pressure difference between the inlet and outlet of the air side is large, the pressure of the air outlet 9 decreases and the volume increases. Therefore, the air flow rate is prevented from being too fast by increasing the cross-sectional area of ​​the air outlet 9; on the third hand, the air inlet 6 and the hydrogen inlet 5 of the hydrogen plate 1 and the oxygen plate 2 are arranged on the same side, avoiding the problem of excessive pressure difference between hydrogen and air at the air outlet 9, thereby improving the life of the fuel cell stack.

[0029] For further reference, Figure 1 and Figure 4 The hydrogen flow channel 3 and the air flow channel 4 of this embodiment both include an air inlet distribution area 11, a reaction area 12 and an air outlet distribution area 13. The reaction area 12 is provided with a plurality of grooves formed by a plurality of reaction ridges 20 arranged in parallel, which helps to evenly distribute air and hydrogen.

[0030] Among them, reference Figure 1 and Figure 2 The inlet distribution area 11 and the outlet distribution area 13 of the hydrogen flow channel 3 are both provided with a distribution island 14 and a hydrogen guide ridge 15, the hydrogen guide ridge 15 is connected to the reaction ridge 20, the distribution island 14 is evenly arranged at the inlet end of the hydrogen guide ridge 15, the hydrogen entering the reaction zone 12 from the inlet distribution area 11 of the hydrogen flow channel 3 passes through the distribution island 14 and the hydrogen guide ridge 15 and then evenly enters different positions of the reaction zone 12 for reaction, and the inlet distribution area 11 and the outlet distribution area 13 of the air flow channel 4 are provided with an air guide ridge 16, the air guide ridge 16 extends from the reaction zone 12 to the middle of the inlet end of the inlet distribution area 11 and the middle of the outlet end of the outlet distribution area 13, respectively, so that the air evenly enters the reaction zone 12, thereby improving the reaction efficiency. After the reaction, the hydrogen is redistributed through the hydrogen guide ridge 15 and the distribution island 14. Specifically, the distribution island 14 is a cylinder, so that the hydrogen and air collide on the cylinder when entering and diffuse and redistribute.

[0031] refer to Figure 3 and Figure 6In the present embodiment, the depth of the air inlet distribution area 11 and the air outlet distribution area 13 is 0.03-0.07 mm greater than the depth of the reaction zone 12. Specifically, the depth of the air inlet distribution area 11 and the air outlet distribution area 13 is 0.05 mm greater than the depth of the reaction zone 12. Even if the depth difference H between the air inlet distribution area 11 and the air outlet distribution area 13 and the depth of the reaction zone 12 is 0.05 mm, after hydrogen and air enter and leave the reaction zone 12, there is a certain amount of hydrogen and air buffer in the air inlet distribution area 11 and the air outlet distribution area 13, which is beneficial to the low-temperature start-up of the fuel cell stack.

[0032] refer to Figure 1 and Figure 4 In this embodiment, both the hydrogen plate 1 and the oxygen plate 2 are provided with inspection ports 17 to facilitate electrical performance testing of the hydrogen plate 1 and the oxygen plate 2.

[0033] Furthermore, both the hydrogen electrode plate 1 and the oxygen electrode plate 2 are provided with positioning holes 18, which facilitates the alignment and installation of the hydrogen electrode plate 1 and the oxygen electrode plate 2, thereby improving the quality of the installation.

[0034] In this embodiment, the air inlet 6 is arranged between the hydrogen inlet 5 and the coolant inlet 7, and the air outlet 9 is arranged between the hydrogen outlet 8 and the coolant outlet 10, so as to optimize the fluid distribution on the air side and make the reaction of air and hydrogen evenly distributed, thereby making the current generated by the fuel cell reaction more evenly distributed.

[0035] Among them, both the hydrogen electrode plate 1 and the oxygen electrode plate 2 are provided with sealing grooves 19, and the sealing grooves 19 are arranged around the hydrogen flow channel 3, the air flow channel 4, the hydrogen inlet 5, the air inlet 6 and the coolant inlet 7, so that the hydrogen and air are isolated from the coolant by the sealing grooves 19, thereby ensuring the stability and safety of the fuel cell.

[0036] In summary, on the one hand, the cross-sectional area of ​​the hydrogen inlet 5 of the present invention is larger than the cross-sectional area of ​​the hydrogen outlet 8, thereby reducing the flow rate of hydrogen at the hydrogen outlet 8, which is beneficial to increase the flow rate and facilitate the accelerated discharge of water produced after the reaction; on the second hand, the cross-sectional area of ​​the air inlet 6 is smaller than the cross-sectional area of ​​the air outlet 9. Since the pressure difference between the inlet and outlet of the air side is large, the pressure of the air outlet 9 decreases and the volume increases. Therefore, the air flow rate is prevented from being too fast by increasing the cross-sectional area of ​​the air outlet 9; on the third hand, the air inlet 6 and the hydrogen inlet 5 of the hydrogen plate 1 and the oxygen plate 2 are arranged on the same side, avoiding the problem of excessive pressure difference between hydrogen and air at the air outlet 9, thereby improving the life of the fuel cell stack.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A fuel cell bipolar plate, characterized in that: It comprises a hydrogen plate and an oxygen plate, wherein the hydrogen plate is provided with a hydrogen flow channel, and the oxygen plate is provided with an air flow channel, wherein the air inlet ends of the hydrogen flow channel and the air flow channel are both provided with a hydrogen inlet, an air inlet and a coolant inlet, and the air outlet ends of the hydrogen flow channel and the air flow channel are both provided with a hydrogen outlet, an air outlet and a coolant outlet, wherein the cross-sectional area of ​​the hydrogen inlet is greater than the cross-sectional area of ​​the hydrogen outlet, and the cross-sectional area of ​​the air inlet is smaller than the cross-sectional area of ​​the air outlet; The hydrogen flow channel and the air flow channel both include an inlet distribution area, a reaction area and an outlet distribution area, and the reaction area is provided with a plurality of grooves formed by a plurality of reaction ridges arranged in parallel; The depth of the inlet distribution area and the outlet distribution area is 0.03-0.07 mm greater than the depth of the reaction area; The inlet distribution area and the outlet distribution area of ​​the hydrogen flow channel are both provided with distribution islands and hydrogen guide ridges, the hydrogen guide ridges are connected to the reaction ridges, and the distribution islands are evenly arranged at the inlet end of the hydrogen guide ridges; The distribution island is a cylinder; The air inlet distribution area and the air outlet distribution area of ​​the air flow channel are provided with air guide ridges, and the air guide ridges extend from the reaction area to the middle of the air inlet end of the air inlet distribution area and the middle of the air outlet end of the air outlet distribution area respectively.

2. The fuel cell bipolar plate according to claim 1, characterized in that: The hydrogen plate and the oxygen plate are both provided with inspection ports.

3. The fuel cell bipolar plate according to claim 1, characterized in that: The hydrogen plate and the oxygen plate are both provided with positioning holes.

4. The fuel cell bipolar plate according to claim 1, characterized in that: The air inlet is arranged between the hydrogen inlet and the coolant inlet, and the air outlet is arranged between the hydrogen outlet and the coolant outlet.

5. The fuel cell bipolar plate according to claim 1, characterized in that: The hydrogen electrode plate and the oxygen electrode plate are both provided with sealing grooves, and the sealing grooves are arranged along the periphery of the hydrogen flow channel, the air flow channel, the hydrogen inlet, the air inlet and the coolant inlet.

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