Radial flow field bipolar plate with multi-inlet structure and proton exchange membrane fuel cell

Abstract

The present invention relates to the field of proton exchange membrane fuel cell technology, disclosing a radial flow field bipolar plate and a proton exchange membrane fuel cell with multiple air inlet structures. A cathode flow field and an anode flow field are provided on the upper and lower surfaces of the bipolar plate, respectively. The cathode flow field inlets air in the center and outlets air at the corners, while the anode flow field inlets air at the corners and outlets air to the sides. Gas diffusion is achieved through multiple multi-stage flow channels radiating outward from the center, with adjacent flow channels separated by ribs. This solution can improve the performance and operating efficiency of proton exchange membrane fuel cells and achieve the assembly capability of the bipolar plates.

Description

Technical Field

[0001] The present invention relates to the technical field of proton exchange membrane fuel cells, and in particular to a radial flow field bipolar plate with a multi-air inlet structure and a proton exchange membrane fuel cell. Background Art

[0002] Proton exchange membrane fuel cells (PEMFCs) are environmentally friendly energy conversion devices with high energy conversion rates. Each cell consists of a bipolar plate, a gas diffusion layer, a catalyst layer, and a proton exchange membrane. They generate electricity through a redox reaction between hydrogen and oxygen. PEMFCs can achieve efficiencies of 40% to 60%, significantly exceeding those of traditional internal combustion engines. Consequently, PEMFCs are widely used in transportation, aerospace, power generation, portable power sources, and other fields. In the future, PEMFCs are expected to become a core energy conversion technology in a "hydrogen society."

[0003] The bipolar plate is an important component of the proton exchange membrane fuel cell. Its function is to discharge excess water produced by the reaction, distribute the reaction gas, collect the generated current and conduct heat, playing a vital role in the performance of the proton exchange membrane fuel cell.

[0004] The bipolar plate flow field structures of proton exchange membrane fuel cells that have been developed include parallel flow field structures composed of multiple straight flow channels in parallel. The main problem is that the single gas flow path leads to uneven distribution of the reaction gas and low reaction gas utilization, resulting in poor battery performance; the main problem of the serpentine flow field structure composed of multiple curved flow channels is that the pressure loss of the reaction gas passing through the bends is too large, which makes the battery parasitic power too large and the reaction gas outlet is prone to flooding. Summary of the Invention

[0005] In response to the problems in the prior art, the present invention discloses a radial flow field bipolar plate and a proton exchange membrane fuel cell with a multi-inlet structure. This solution can improve the performance and working efficiency of the proton exchange membrane fuel cell and realize the assembly capability of the bipolar plate.

[0006] A radial flow field bipolar plate with a multi-inlet structure, wherein a cathode flow field is provided on the upper surface of the bipolar plate, a vertical, transparent cathode side air inlet channel is provided at the center of the cathode flow field, a horizontal cathode flow field gas inlet is provided at the root of the cathode side air inlet channel, a vertical, transparent cathode side air outlet channel is provided at the corner point of the cathode flow field, and a horizontal cathode flow field gas outlet is provided on the side wall of the cathode side air outlet channel; an anode flow field is provided on the lower surface of the bipolar plate, a vertical anode side air inlet channel is provided at the corner point of the anode flow field, a horizontal anode flow field gas inlet is provided at the root of the anode side air inlet channel, a vertical, transparent anode side air outlet channel is provided at the midpoint of the edge of the anode flow field, and a horizontal anode flow field gas outlet is provided on the side wall of the anode side air outlet channel; both the cathode flow field and the anode flow field are provided with multiple multi-level flow channels radiating outward from the center, and adjacent flow channels are separated by ribs.

[0007] Preferably, the multi-stage flow channel includes a main flow channel and an auxiliary flow channel, the main flow channel is distributed in a crisscross structure on the flow field, and the auxiliary flow channel is located between two adjacent main flow channels of the crisscross structure.

[0008] Preferably, the auxiliary flow channels are multiple channels parallel to each other.

[0009] Preferably, the ribs on both sides of the main flow channel leading to the midpoint of the flow field edge are discontinuous structures.

[0010] Preferably, a cathode side gas channel boss is provided at the center of the cathode flow field, and cathode side gas channel grooves are provided at the corner points of the cathode flow field.

[0011] Preferably, anode-side gas channel bosses are provided at corner points of the anode flow field, and an anode-side gas channel groove is provided at the center of the anode flow field.

[0012] Preferably, the cathode side gas channel boss cooperates with the anode side gas channel groove, and the anode side gas channel boss cooperates with the cathode side gas channel groove, so that the battery as a whole reaches a compact and stable state.

[0013] The present invention also discloses a proton exchange membrane fuel cell, including a membrane electrode, wherein a radial flow field bipolar plate with a multi-air inlet structure as described above is respectively provided at the upper and lower ends of the membrane electrode, and the upper and lower radial flow field bipolar plates cooperate with each other to form a detachable proton exchange membrane fuel cell.

[0014] The beneficial effects of the present invention are:

[0015] 1. The multi-inlet radial flow field structure can reduce the difference in gas concentration and flow velocity between the central area and the edge area of ​​the flow field, making the distribution of the reaction gas in the flow field more uniform.

[0016] 2. The gas flow path is short and radial. Compared with complex structures such as serpentine flow fields, the gas flow resistance is small and the pressure drop is low, which reduces the energy consumption of the gas supply system and improves the efficiency of the fuel cell system.

[0017] 3. The flow channel width and depth are relatively uniform, with the primary channel width set to 1mm and the rib width to 0.5mm; the secondary channel width is set to 0.8mm and the rib width to 0.4mm. This setting can effectively reduce the accumulation of liquid water, allowing liquid water to drain more smoothly from the electrode surface in a radial direction, reducing flooding. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 This is a schematic diagram of the cathode angle of the proton exchange membrane fuel cell composed of the present invention;

[0020] Figure 2 This is a schematic diagram of the anode angle of the proton exchange membrane fuel cell composed of the present invention;

[0021] Figure 3 Schematic diagram of the anode side structure of the present invention;

[0022] Figure 4 for Figure 3 A magnified schematic diagram of part C;

[0023] Figure 5 for Figure 3 The enlarged schematic diagram of part D in the middle;

[0024] Figure 6 Schematic diagram of the cathode side structure of the present invention;

[0025] Figure 7 for Figure 6 A magnified schematic diagram of part A;

[0026] Figure 8 for Figure 6 A magnified schematic diagram of part B;

[0027] 1. Radial flow field bipolar plate; 2. Membrane electrode; 3. Cathode side gas channel boss; 4. Anode side gas channel groove; 5. Anode side gas channel boss; 6. Cathode side gas channel groove; 7. Rib; 8. Cathode side air inlet channel; 9. Cathode flow field gas inlet; 10. Cathode side air outlet channel; 11. Cathode flow field gas outlet; 12. Anode flow field gas inlet; 13. Anode side air inlet channel; 14. Anode flow field gas outlet; 15. Anode side air outlet channel. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0029] Existing proton exchange membrane fuel cell technology can suffer from issues such as edge effects caused by uneven distribution of reactant gases within the flow field, flooding due to poor drainage, high pressure drops that limit battery system efficiency, and difficulty assembling conventional bipolar plates. Therefore, the present invention utilizes a multi-inlet radial flow field to facilitate assembly of bipolar plates, thereby improving the single flow path of reactant gases and reducing pressure losses, thereby enhancing battery efficiency.

[0030] The present invention will be further described below with reference to the accompanying drawings:

[0031] like Figure 1-8 FIG. 1 is a schematic diagram of the overall structure of the radial flow field easy-to-assemble bipolar plate of the proton exchange membrane fuel cell with multiple air inlet structures according to the present invention.

[0032] The membrane electrode 2 is located between two radial flow field bipolar plates 1. The upper and lower end surfaces of the radial flow field bipolar plates are processed with flow fields. Among them, the cathode side gas channel boss 3 located at the center of the flow field below the membrane electrode 2 is matched with the anode side gas channel groove 4 located above the membrane electrode 2. The anode side gas channel boss 5 located above the membrane electrode 2 and around the flow field is matched with the cathode side gas channel groove 6 located below the membrane electrode 2, so that the battery as a whole reaches a compact and stable state.

[0033] Both the cathode flow field and the anode flow field are provided with multi-stage flow channels, which are separated by multiple groups of ribs 7. Adjacent ribs 7 in the same group of ribs 7 are parallel to each other, so that the gas flow path is not too single, the gas distribution state is improved, and uneven gas distribution is avoided.

[0034] The multi-stage flow channels consist of main channels and auxiliary channels. The main channels are arranged in a 'M'-shaped structure across the flow field. Specifically, they include side channels connected to the edges of the bipolar plates and corner channels connected to the corners of the bipolar plates. The auxiliary channels are located between adjacent main channels in the 'M'-shaped structure. The auxiliary channels are multiple, parallel channels arranged perpendicular to the edges of the bipolar plates.

[0035] The ribs on both sides of the main channel leading to the midpoint of the flow field edge are discontinuous structures. The main channel width is set to 1mm, and the rib width is 0.5mm; the secondary channel width is set to 0.8mm, and the rib width is 0.4mm. This setting can effectively reduce the accumulation of liquid water.

[0036] The cathode gas flows through the cathode side of each bipolar plate through the cathode side air inlet channel 8, while oxygen enters the cathode flow field through the cathode flow field gas inlet 9, and the residual reaction gas flows out of the cathode flow field through the cathode flow field gas outlet 11 and flows out of the battery through the cathode side air outlet channel 10.

[0037] The anode gas flows through the anode side of each bipolar plate through the anode side air inlet channel 13, while the hydrogen enters the anode flow field through the anode flow field gas inlet 12, and the residual reaction gas flows out of the anode flow field through the anode flow field gas outlet 14 and flows out of the battery through the anode side air outlet channel 15.

[0038] The multi-inlet radial flow field structure improves the uniformity of edge reaction gas distribution, resolving the problem of uneven gas distribution at the edges of conventional radial flow fields, thereby enhancing battery performance and efficiency. Because the gas flow path is short and free of bends, it facilitates smooth gas flow, minimizes pressure loss, and thus reduces battery energy loss.

[0039] In summary, the radial flow field based on the multi-inlet structure has the advantages of uniform reaction gas distribution, small pressure loss, and not prone to flooding, making this design have practical application value in proton exchange membrane fuel cells.

[0040] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A radial flow field bipolar plate with a multi-inlet structure, characterized in that: A cathode flow field is provided on the upper surface of the bipolar plate, a vertical, transparent cathode side air inlet channel (8) is provided at the center of the cathode flow field, a horizontal cathode flow field gas inlet (9) is provided at the root of the cathode side air inlet channel (8), a vertical, transparent cathode side air outlet channel (10) is provided at the corner point of the cathode flow field, and a horizontal cathode flow field gas outlet (11) is provided on the side wall of the cathode side air outlet channel (10); An anode flow field is provided on the lower surface of the bipolar plate, a vertical anode side air inlet channel (13) is provided at a corner point of the anode flow field, a horizontal anode flow field gas inlet (12) is provided at the root of the anode side air inlet channel (13), a vertical, vertically transparent anode side air outlet channel (15) is provided at the midpoint of the edge line of the anode flow field, and a horizontal anode flow field gas outlet (14) is provided on the side wall of the anode side air outlet channel; The cathode flow field and the anode flow field are both provided with a plurality of multi-level flow channels radiating outward from the center, and adjacent flow channels are separated by ribs.

2. The radial flow field bipolar plate with multiple air inlet structures according to claim 1, characterized in that: The multi-stage flow channel includes a main flow channel and an auxiliary flow channel. The main flow channel is distributed in a crisscross structure on the flow field, and the auxiliary flow channel is located between two adjacent main flow channels in the crisscross structure.

3. The radial flow field bipolar plate with multiple air inlet structures according to claim 2, characterized in that: The auxiliary flow channels are multiple channels parallel to each other.

4. The radial flow field bipolar plate with multiple air inlet structures according to claim 2, characterized in that: The ribs on both sides of the main channel leading to the midpoint of the flow field edge are discontinuous structures.

5. The radial flow field bipolar plate with multiple air inlet structures according to claim 1, characterized in that: A cathode side gas channel boss (3) is provided at the center of the cathode flow field, and cathode side gas channel grooves (6) are provided at the corner points of the cathode flow field.

6. The radial flow field bipolar plate with multiple air inlet structures according to claim 5, characterized in that: An anode side gas channel boss (5) is provided at a corner point of the anode flow field, and an anode side gas channel groove (4) is provided at the center of the anode flow field.

7. The radial flow field bipolar plate with multiple air inlet structures according to claim 6, characterized in that: The cathode side gas channel boss (3) cooperates with the anode side gas channel groove (4), and the anode side gas channel boss (5) cooperates with the cathode side gas channel groove (6), thereby making the battery as a whole compact and stable.

8. A proton exchange membrane fuel cell, characterized in that: It comprises a membrane electrode (2), wherein the upper and lower ends of the membrane electrode (2) are each provided with a radial flow field bipolar plate with a multi-air inlet structure according to any one of claims 1 to 7.

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