A bipolar plate structure

Abstract

The application relates to a bipolar plate structure, which comprises an anode single plate and a cathode single plate, the front surface of the anode single plate is provided with a hydrogen flow channel, the front surface of the cathode single plate is provided with an air flow channel, a cooling water flow channel is formed between the two single plates, an air inlet end, a hydrogen inlet end, an air outlet end and a hydrogen outlet end are symmetrically arranged along the central axis in the gas flow direction, two cooling water inlet ends are symmetrically arranged along the central axis in the gas flow direction, in the vertical direction of the gas flow direction, the two cooling water inlet ends are located on the two sides, the air inlet end and the hydrogen outlet end are located in the middle, two cooling water outlet ends are symmetrically arranged along the central axis in the gas flow direction, in the vertical direction of the gas flow direction, the two cooling water outlet ends are located on the two sides, the air outlet end and the hydrogen inlet end are located in the middle, the hydrogen flow channel, the air flow channel and the cooling water flow channel are symmetrically arranged along the central axis in the gas flow direction, so that the service life of the fuel cell is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and more particularly to a bipolar plate structure. Background Technology

[0002] As the global energy structure shifts towards cleaner and lower-carbon energy, fuel cells, especially proton exchange membrane fuel cells (PEMFCs), are showing broad application prospects in transportation and stationary power generation due to their advantages such as high efficiency, high energy density, rapid low-temperature start-up, and zero emissions. To enhance the commercial competitiveness of fuel cells, their core components are continuously being developed towards higher power density, longer lifespan, and lower cost. As the "skeleton" of the fuel cell stack, bipolar plates undertake multiple key functions, including distributing reactant gases, collecting current, conducting heat, and separating the reaction medium. Their flow field design directly determines the uniformity of reactant distribution, hydrothermal management efficiency, and parasitic power consumption of the system, making them one of the core factors affecting the overall performance, efficiency, and consistency of the battery.

[0003] A widely used design in the prior art involves placing the coolant inlet and outlet in the central area, while the hydrogen inlet and outlet, and the air inlet and outlet, are located on either side of the coolant inlet. Refer to Chinese patent CN2017219027575, which discloses this structure. In this design, after the reactant gas (hydrogen or air) flows in from the inlet on the side of the electrode, the flow channel needs to be angled and extended throughout the entire reaction area. This "side-in, oblique-entry" flow channel layout results in a tortuous and asymmetrical gas flow path at the inlet section, easily creating uneven velocity and concentration fields in the distribution area. Some channels may experience insufficient ventilation due to excessive resistance, forming "dead zones," while others may have excessive flow. This uneven distribution reduces the overall catalyst utilization rate, causes local hot spots or flooding, and increases the total pressure drop of gas delivery, thereby increasing the power consumption of the air compressor or hydrogen circulation pump and impairing the system's net efficiency.

[0004] Therefore, it is necessary to provide a bipolar plate structure that solves the above-mentioned technical problems. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a bipolar plate structure with uniform gas distribution.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a bipolar plate structure, comprising: an anode monopolar plate and a cathode monopolar plate connected to each other, wherein one end of the anode monopolar plate is provided with an anode hydrogen outlet, an anode air inlet, and an anode cooling water inlet, and the other end of the anode monopolar plate is provided with an anode hydrogen inlet, an anode air outlet, and an anode cooling water outlet; one end of the cathode monopolar plate is provided with a cathode hydrogen outlet, a cathode air inlet, and a cathode cooling water inlet, and the other end of the cathode monopolar plate is provided with a cathode hydrogen inlet, a cathode air outlet, and a cathode cooling water outlet, characterized in that: the front side of the anode monopolar plate... The flow channel is a hydrogen flow channel, and the front flow channel of the cathode monopolar plate is an air flow channel. After the anode monopolar plate and the cathode monopolar plate are attached, a cooling water flow channel is formed between the anode monopolar plate and the cathode monopolar plate. The anode hydrogen inlet and the cathode hydrogen inlet are overlapped in the thickness direction to form a hydrogen inlet end. The anode hydrogen outlet and the cathode hydrogen outlet are overlapped in the thickness direction to form a hydrogen outlet end. The anode air inlet and the cathode air inlet are overlapped in the thickness direction to form an air inlet end. The anode air outlet and the cathode air outlet are overlapped in the thickness direction to form an air outlet end. At the inlet and outlet, the anode cooling water inlet and the cathode cooling water inlet overlap in the thickness direction to form a cooling water inlet end, and the anode cooling water outlet and the cathode cooling water outlet overlap in the thickness direction to form a cooling water outlet end. The hydrogen flow channels communicate with both the hydrogen inlet end and the hydrogen outlet end, the air flow channels communicate with both the air inlet end and the air outlet end, and the cooling water flow channels communicate with both the cooling water inlet end and the cooling water outlet end. The air inlet end, hydrogen inlet end, air outlet end, and hydrogen outlet end are symmetrically arranged along the central axis of the gas flow direction. There are two cooling water inlets, which are symmetrically arranged along the central axis of the gas flow direction. In the direction perpendicular to the gas flow direction, the two cooling water inlets are located on both sides, and the air inlet and hydrogen outlet are located in the middle. There are also two cooling water outlets, which are symmetrically arranged along the central axis of the gas flow direction. In the direction perpendicular to the gas flow direction, the two cooling water outlets are located on both sides, and the air outlet and hydrogen inlet are located in the middle. The hydrogen flow channel, air flow channel, and cooling water flow channel are symmetrically arranged along the central axis of the gas flow direction.

[0007] Preferably, a bipolar plate structure in this invention is further configured such that the hydrogen flow channel includes a hydrogen inlet distribution area channel, a hydrogen reaction area channel, and a hydrogen outlet distribution area channel.

[0008] Preferably, the bipolar plate structure of the present invention is further configured such that the hydrogen inlet distribution area flow channel and the hydrogen outlet distribution area flow channel are both arranged in a fan shape, and the hydrogen reaction area flow channel is arranged as a direct flow channel or a wave flow channel.

[0009] Preferably, the bipolar plate structure of the present invention is further configured such that the width of the hydrogen inlet distribution area channel and the hydrogen outlet distribution area channel increases progressively to both sides along the central axis in the gas flow direction.

[0010] Preferably, the bipolar plate structure of the present invention is further configured such that the hydrogen inlet distribution area flow channel and the hydrogen outlet distribution area flow channel are both arranged in a dot matrix pattern.

[0011] Preferably, a bipolar plate structure in this invention is further configured such that the air flow channel includes an air inlet distribution area flow channel, an air reaction area flow channel, and an air outlet distribution area flow channel.

[0012] Preferably, the bipolar plate structure of the present invention is further configured such that the air inlet distribution area channel and the air outlet distribution area channel are both arranged in a fan shape, and the air reaction area channel is arranged in a direct flow channel or a wave channel.

[0013] Preferably, the bipolar plate structure of the present invention is further configured such that the width of the air inlet distribution area channel and the air outlet distribution area channel increases progressively to both sides along the central axis in the gas flow direction.

[0014] Preferably, the bipolar plate structure of the present invention is further configured such that the air inlet distribution area channel and the air outlet distribution area channel are both arranged in a dot matrix pattern.

[0015] Preferably, a bipolar plate structure in this invention is further configured such that the front side of both the anode monopolar plate and the cathode monopolar plate are provided with grooves for installing seals.

[0016] Compared with existing technologies, the present invention has the following advantages: The bipolar plate structure of the present invention symmetrically arranges the air inlet, hydrogen inlet, air outlet, and hydrogen outlet along the central axis of the gas flow direction. Compared with the existing design where the hydrogen and air inlets are located on both sides of the cooling chamber, the gas no longer needs to turn at a certain angle from the side of the plate and extend into the entire reaction area, avoiding the occurrence of the longest and shortest flow channels, thus preventing uneven gas distribution. Secondly, after the gas enters the distribution zone, the width of the flow channels (narrow in the middle and wide at the sides) can be adjusted to ensure a more even distribution of gas in each flow channel, which is beneficial to ensuring the consistency of the chemical reaction in the fuel cell. When the plates and membrane electrode assembly are stacked and subjected to pressure, the bipolar plate in the present invention, being an axisymmetric structure, experiences more uniform force under pressure, further ensuring the flow rate of each bipolar plate and improving the overall lifespan of the fuel cell. Furthermore, compared to the existing technology where the bipolar plate cooling cavity is in the middle and the air and hydrogen cavities are located on both sides of the cooling cavity, the present invention places the bipolar plate air cavity and hydrogen cavity in the middle of the bipolar plate, and places the cooling cavity on both sides of the air cavity and hydrogen cavity. This arrangement is conducive to the uniformity of gas distribution, ensures the uniformity of gas flow in each flow channel, and greatly improves the life and performance of the fuel cell. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the bipolar plate in this invention.

[0018] Figure 2 This is a schematic diagram of the bipolar plate in the present invention, showing the case where the anode monopolar plate and the cathode monopolar plate are separated.

[0019] Figure 3 This is a schematic diagram of the anode monopolar plate in this invention.

[0020] Figure 4 This is a schematic diagram of the cathode monopole plate in this invention.

[0021] Figures 1 to 4In the middle section: 1. Anode monopolar plate; 10. Anode hydrogen outlet; 11. Anode air inlet; 12. Anode cooling water inlet; 13. Anode hydrogen inlet; 14. Anode air outlet; 15. Anode cooling water outlet; 16. Hydrogen flow channel; 160. Hydrogen inlet distribution area flow channel; 161. Hydrogen reaction zone flow channel; 162. Hydrogen outlet distribution area flow channel; 17. First channel; 2. Cathode monopolar plate; 20. Cathode hydrogen outlet; 21. Cathode air inlet; 22. Cathode cooling water inlet; 23. Cathode hydrogen inlet. 24. Cathode air outlet; 25. Cathode cooling water outlet; 26. Air flow channel; 260. Air inlet distribution area flow channel; 261. Air reaction area flow channel; 262. Air outlet distribution area flow channel; 27. Second channel; 3. Cooling water flow channel; 30. Cooling water inlet distribution area flow channel; 31. Cooling water reaction area flow channel; 32. Cooling water outlet distribution area flow channel; 4. Hydrogen inlet end; 5. Hydrogen outlet end; 6. Air inlet end; 7. Air outlet end; 8. Cooling water inlet end; 9. Cooling water outlet end. Detailed Implementation

[0022] The bipolar plate of the present invention will be further described in detail below through specific embodiments.

[0023] Please see Figures 1 to 4 A bipolar plate structure includes an anode monopolar plate 1 and a cathode monopolar plate 2 connected to each other. In this embodiment, the anode monopolar plate 1 and the cathode monopolar plate 2 are connected by welding. One end of the anode monopolar plate 1 is provided with an anode hydrogen outlet 10, an anode air inlet 11, and an anode cooling water inlet 12. The other end of the anode monopolar plate 1 is provided with an anode hydrogen inlet 13, an anode air outlet 14, and an anode cooling water outlet 15. One end of the cathode monopolar plate 2 is provided with a cathode hydrogen outlet 20, a cathode air inlet 21, and a cathode cooling water inlet 22. The other end of the cathode monopolar plate 2 is provided with a cathode hydrogen inlet 23. The cathode has an air outlet 24 and a cooling water outlet 25. The front flow channel of the anode monopolar plate 1 is a hydrogen flow channel 16, and the front flow channel of the cathode monopolar plate 2 is an air flow channel 26. After the anode monopolar plate 1 and the cathode monopolar plate 2 are attached, a cooling water flow channel 3 is formed between the anode monopolar plate 1 and the cathode monopolar plate 2. The cooling water flow channel 3 includes a cooling water inlet distribution area flow channel 30, a cooling water reaction area flow channel 31, and a cooling water outlet distribution area flow channel 32. In this embodiment, the cooling water inlet distribution area flow channel 30 and the cooling water outlet distribution area flow channel 32 are arranged in a matrix, and the cooling water reaction area flow channel 31 is arranged as a direct flow channel.

[0024] The anode hydrogen inlet 13 and the cathode hydrogen inlet 23 are arranged to overlap in the thickness direction to form a hydrogen inlet end 4. The anode hydrogen outlet 10 and the cathode hydrogen outlet 20 are arranged to overlap in the thickness direction to form a hydrogen outlet end 5. The anode air inlet 11 and the cathode air inlet 21 are arranged to overlap in the thickness direction to form an air inlet end 6. The anode air outlet 14 and the cathode air outlet 24 are arranged to overlap in the thickness direction to form an air outlet end 7. The anode cooling water inlet 12 and the cathode cooling water inlet 22 are arranged to overlap in the thickness direction to form a cooling water inlet end 8. The anode cooling water outlet 15 and the cathode cooling water outlet 25 are arranged to overlap in the thickness direction to form a cooling water outlet end 9. The hydrogen flow channel 16 is connected to the hydrogen inlet end 4 and the hydrogen outlet end 5 respectively. The air flow channel 26 is connected to the air inlet end 6 and the air outlet end 7 respectively. The cooling water flow channel 3 is connected to the cooling water inlet end 8 and the cooling water outlet end 9 respectively.

[0025] The air inlet 6, hydrogen inlet 4, air outlet 7, and hydrogen outlet 5 are symmetrically arranged along the central axis of the gas flow direction. The gas flow direction refers to the direction of gas from the inlet to the outlet. In this embodiment, since the bipolar plate is rectangular, the gas flow direction is the length direction of the rectangle. Therefore, the central axis of the gas flow direction is the central axis of the length direction. There are two cooling water inlets 8, which are symmetrically arranged along the central axis of the gas flow direction. In the direction perpendicular to the gas flow direction, the two cooling water inlets 8 are located on both sides, and the air inlet 6 and hydrogen outlet 5 are located in the middle. There are also two cooling water outlets 9, which are symmetrically arranged along the central axis of the gas flow direction. In the direction perpendicular to the gas flow direction, the two cooling water outlets 9 are located on both sides, and the air outlet 7 and hydrogen inlet 4 are located in the middle. The hydrogen flow channel 16, air flow channel 26, and cooling water flow channel 3 are symmetrically arranged along the central axis of the gas flow direction. In this embodiment, since the bipolar plate is rectangular, the gas flow direction is the length direction of the rectangle, and therefore the perpendicular direction of the gas flow direction is the width direction of the rectangle.

[0026] The hydrogen flow channel 16 includes a hydrogen inlet distribution channel 160, a hydrogen reaction channel 161, and a hydrogen outlet distribution channel 162. The widths of the hydrogen inlet distribution channel 160 and the hydrogen outlet distribution channel 162 increase gradually towards both sides along the central axis of the gas flow direction. Because the middle channel is short with low resistance and allows more gas to flow, while the side channels are long with high resistance and allow less gas to flow, designing the channels as narrow in the middle and wide at both sides allows the gas to be more evenly distributed in each channel, which is beneficial for ensuring the consistency of the chemical reaction in the fuel cell. In this embodiment, both the hydrogen inlet distribution channel 160 and the hydrogen outlet distribution channel 162 are arranged in a fan shape, and the hydrogen reaction channel 161 is a direct-flow channel. Of course, in other embodiments, both the hydrogen inlet distribution channel 160 and the hydrogen outlet distribution channel 162 are arranged in a matrix pattern, and the hydrogen reaction channel 161 is a wavy channel, which can also achieve the present invention.

[0027] The air flow channel 26 includes an air inlet distribution area flow channel 260, an air reaction area flow channel 261, and an air outlet distribution area flow channel 262. In this embodiment, both the air inlet distribution area flow channel 260 and the air outlet distribution area flow channel 262 are arranged in a fan shape, while the air reaction area flow channel 261 is arranged as a direct flow channel. The width of the air inlet distribution area flow channel 260 and the air outlet distribution area flow channel 262 increases gradually from the central axis along the gas flow direction to both sides, which is also to make the gas more evenly distributed in each flow channel, which is beneficial to ensuring the consistency of the chemical reaction in the fuel cell. Of course, in other embodiments, the air inlet distribution area flow channel 260 and the air outlet distribution area flow channel 262 are arranged in a dot matrix pattern, and the air reaction area flow channel 261 is arranged as a wave flow channel, which can also realize the present invention. The front side of the anode monopole plate 1 is provided with a first groove 17 for installing a seal, and the front side of the cathode monopole plate 2 is provided with a second groove 27 for installing a seal. Both the first groove 17 and the second groove 27 are prior art.

[0028] In summary, the bipolar plate structure in this invention improves the arrangement of the air inlet, hydrogen inlet, cooling inlet, and flow channel, thereby achieving uniform gas distribution and improving the service life of the fuel cell.

[0029] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some examples of its application, and are not intended to limit the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention.

Claims

1. A bipolar plate structure, comprising: An interconnected anode and cathode monopolar plates are provided. One end of the anode monopolar plate has an anode hydrogen outlet, an anode air inlet, and an anode cooling water inlet; the other end of the anode monopolar plate has an anode hydrogen inlet, an anode air outlet, and an anode cooling water outlet. One end of the cathode monopolar plate has a cathode hydrogen outlet, a cathode air inlet, and a cathode cooling water inlet; the other end of the cathode monopolar plate has a cathode hydrogen inlet, a cathode air outlet, and a cathode cooling water outlet. The anode monopolar plate has a front flow channel that is a hydrogen flow channel, and the cathode monopolar plate has a front flow channel that is an air flow channel. After the anode and cathode monopolar plates are bonded together, a cooling water channel is formed between them. The anode hydrogen inlet and cathode hydrogen inlet overlap in the thickness direction to form a hydrogen inlet end. The anode hydrogen outlet and cathode hydrogen outlet overlap in the thickness direction to form a hydrogen outlet end. The anode air inlet and cathode air inlet overlap in the thickness direction to form an air inlet end. The anode air outlet and cathode air outlet overlap in the thickness direction to form an air outlet end. The anode cooling water inlet and cathode cooling water outlet overlap in the thickness direction to form an air outlet end. The cooling water inlets overlap in the thickness direction to form the cooling water inlet end. The anode cooling water outlet and cathode cooling water outlet overlap in the thickness direction to form the cooling water outlet end. The hydrogen flow channels are respectively connected to the hydrogen inlet end and the hydrogen outlet end. The air flow channels are respectively connected to the air inlet end and the air outlet end. The cooling water flow channels are respectively connected to the cooling water inlet end and the cooling water outlet end. The air inlet end, hydrogen inlet end, air outlet end, and hydrogen outlet end are symmetrically arranged along the central axis of the gas flow direction. The number of cooling water inlets... There are two cooling water inlets, symmetrically arranged along the central axis of the gas flow direction. In the direction perpendicular to the gas flow direction, the two cooling water inlets are located on both sides, and the air inlet and hydrogen outlet are located in the middle. There are also two cooling water outlets, symmetrically arranged along the central axis of the gas flow direction. In the direction perpendicular to the gas flow direction, the two cooling water outlets are located on both sides, and the air outlet and hydrogen inlet are located in the middle. The hydrogen flow channel, air flow channel, and cooling water flow channel are symmetrically arranged along the central axis of the gas flow direction.

2. The bipolar plate structure as described in claim 1, characterized in that: The hydrogen flow channels include a hydrogen inlet distribution area flow channel, a hydrogen reaction area flow channel, and a hydrogen outlet distribution area flow channel.

3. The bipolar plate structure as described in claim 2, characterized in that: The hydrogen inlet distribution area and the hydrogen outlet distribution area are both arranged in a fan shape, and the hydrogen reaction area is arranged as a straight channel or a wave channel.

4. The bipolar plate structure as described in claim 3, characterized in that: The widths of the hydrogen inlet distribution area channel and the hydrogen outlet distribution area channel are arranged to increase gradually to both sides along the central axis in the gas flow direction.

5. A bipolar plate structure as described in claim 2, characterized in that: The hydrogen inlet distribution area channel and the hydrogen outlet distribution area channel are both arranged in a dot matrix pattern.

6. The bipolar plate structure as described in claim 1, characterized in that: The airflow channel includes an air inlet distribution area channel, an air reaction area channel, and an air outlet distribution area channel.

7. A bipolar plate structure as described in claim 6, characterized in that: The air inlet distribution area and the air outlet distribution area are both arranged in a fan shape, and the air reaction area is arranged in a straight channel or a wave channel.

8. A bipolar plate structure as described in claim 7, characterized in that: The widths of the air inlet distribution area channel and the air outlet distribution area channel are arranged to increase gradually to both sides along the central axis in the gas flow direction.

9. A bipolar plate structure as described in claim 6, characterized in that: Both the air inlet distribution area flow channel and the air outlet distribution area flow channel are arranged in a dot matrix pattern.

10. A bipolar plate structure as described in claim 1, characterized in that: Both the front side of the anode monopolar plate and the front side of the cathode monopolar plate are provided with grooves for installing seals.

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