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CN-121709650-B - Fuel cell polar plate structure and fuel cell unit cell

CN121709650BCN 121709650 BCN121709650 BCN 121709650BCN-121709650-B

Abstract

The invention discloses a fuel cell polar plate structure and a fuel cell single cell, wherein the fuel cell polar plate structure comprises a polar plate body and a flow field, the flow field is arranged on the polar plate body, the flow field comprises a first air inlet distribution area and a first reaction flow field area, the first air inlet distribution area comprises a plurality of first distribution flow channels arranged side by side, the first reaction flow field area comprises a plurality of first basic flow channels, two of the plurality of first distribution flow channels are respectively a first flow channel and a second flow channel, the length of the first flow channel is smaller than that of the second flow channel, the first flow channel is communicated with N first basic flow channels, the second flow channel is communicated with M first basic flow channels, and N is more than or equal to M. According to the fuel cell polar plate structure, the pressure and the supply quantity of the gas entering the first reaction flow field region from the first gas inlet distribution region are more consistent, so that the reaction rate of the first reaction flow field region is more balanced, and the energy conversion efficiency is improved.

Inventors

  • NIAN FENG
  • CHANG RUI
  • GUO FENGGANG
  • LIU YONGLIANG
  • QU GUANSHU
  • GUO ZIQIAN

Assignees

  • 北汽福田汽车股份有限公司

Dates

Publication Date
20260512
Application Date
20260213

Claims (10)

  1. 1. A fuel cell plate structure, comprising: the two ends of the polar plate body along the first direction (X) are respectively provided with an air inlet and an air outlet; The flow field (10) is arranged on the polar plate body and is positioned between the air inlet and the air outlet, and the flow field (10) is respectively communicated with the air inlet and the air outlet; The flow field (10) comprises a first air inlet distribution area (11) and a first reaction flow field area (21) which are sequentially arranged along the first direction (X), wherein the first air inlet distribution area (11) is used for enabling air to uniformly flow into the first reaction flow field area (21) from the air inlet; The first inlet distribution area (11) comprises a plurality of first distribution flow channels (111) arranged side by side along a second direction (Y), the first reaction flow field area (21) comprises a plurality of first base flow channels (211) arranged side by side along the second direction (Y), the first direction (X) and the second direction (Y) are mutually perpendicular, Two of the plurality of first distribution flow channels (111) are respectively a first flow channel (1111) and a second flow channel (1112), the length of the first flow channel (1111) is smaller than that of the second flow channel (1112), the first flow channel (1111) is communicated with N first basic flow channels (211), the second flow channel (1112) is communicated with M first basic flow channels (211), and N is more than or equal to M, The flow field (10) further comprises a second air inlet distribution area (12) and a second reaction flow field area (22) which are sequentially arranged along the first direction (X), the second air inlet distribution area (12) and the first air inlet distribution area (11) are arranged side by side along the second direction (Y), the second reaction flow field area (22) and the first reaction flow field area (21) are arranged side by side along the second direction (Y), the second air inlet distribution area (12) is used for enabling air to uniformly flow into the second reaction flow field area (22) from the air inlet, the distance between the air inlet and the first reaction flow field area (21) is smaller than the distance between the air inlet and the second reaction flow field area (22), The second air inlet distribution area (12) comprises a plurality of second distribution flow passages (121) which are arranged side by side; The second reaction stream field region (22) comprises a plurality of second base flow channels (221) arranged side by side along the second direction (Y), The flow field (10) further comprises a third air inlet distribution area (13) and a third reaction flow field area (23) which are sequentially arranged along the first direction (X), the third air inlet distribution area (13) is positioned between the first air inlet distribution area (11) and the second air inlet distribution area (12) along the second direction (Y) and is used for enabling air to uniformly flow into the third reaction flow field area (23) from the air inlet, The third intake distribution area (13) comprises a plurality of third distribution flow passages (131) arranged side by side along a second direction (Y); The third reaction flow field region (23) includes a plurality of third base flow channels (231) disposed side by side along a second direction (Y); each of the third distribution flow channels (131) communicates with P of the third base flow channels (231), wherein, Each second distribution flow passage (121) comprises a first branch flow passage (1201) and a second branch flow passage (1202) which are connected in parallel, and the first branch flow passage (1201) and the second branch flow passage (1202) are communicated with Q1 second basic flow passages (221) and satisfy the following conditions: M>P>Q1。
  2. 2. the fuel cell plate structure according to claim 1, wherein, In a direction toward the center of the plate body, The lengths of the plurality of first distribution flow passages (111) gradually increase; Wherein two of the N first base runners (211) corresponding to the first runners (1111) are first side runners and second side runners, the second side runners are positioned on one side of the first side runners close to the second runners (1112), M first base runners (211) corresponding to the second runners (1112), the first base runner (211) close to the second side runner is a third side runner, the first base runner (211) far away from the second side runner is a fourth side runner, The length of the third side runner is smaller than that of the second side runner, the length of the third side runner is larger than that of the first side runner, and the length of the fourth side runner is larger than that of the second side runner.
  3. 3. The fuel cell plate structure according to claim 1, wherein the first distribution flow channel (111) includes a first segment (101) and a second segment (102) in a flow direction of the gas flow, the first segment (101) extending in the first direction (X), the second segment (102) extending toward a center of the plate body to communicate with the first base flow channel (211) extending in the first direction (X), wherein the first segments (101) of the plurality of first distribution flow channels (111) are equal in length toward the center of the plate body, and the lengths of the plurality of second segments (102) gradually increase.
  4. 4. The fuel cell plate structure according to claim 1, wherein, The second distribution flow channel (121) comprises a primary flow channel (1211) and a secondary flow channel (1212), wherein the primary flow channel (1211) is communicated between the air inlet and the secondary flow channel (1212), and the secondary flow channel (1212) comprises the first branch flow channel (1201) and the second branch flow channel (1202).
  5. 5. The fuel cell plate structure according to claim 4, wherein, The primary flow channel (1211) comprises a third section (103) and a fourth section (104), the third section (103) extends along a first direction (X), the fourth section (104) is inclined towards one side away from the first air inlet distribution area (11), wherein a plurality of the third sections (103) have equal lengths and gradually increase in length towards the first air inlet distribution area (11); The second base flow channel (221) comprises a fifth section (105) and a sixth section (106), the fifth section (105) extending in the first direction (X), the sixth section (106) being inclined towards one side of the first intake distribution area (11), The first branch flow channel (1201) and the second branch flow channel (1202) extend along the second direction (Y), the second branch flow channel (1202) is positioned at one side of the first branch flow channel (1201) close to the second reaction flow field region (22), and the length of the first branch flow channel (1201) is larger than that of the second branch flow channel (1202).
  6. 6. The fuel cell plate structure according to claim 1, wherein the cross-sectional area of the first base flow channel (211), the cross-sectional area of the second base flow channel (221), and the cross-sectional area of the third base flow channel (231) are all equal.
  7. 7. The fuel cell plate structure according to claim 1, wherein the second intake distribution area (12) further includes a single flow passage (122), the single flow passage (122) being located on a side of the second distribution flow passage (121) remote from the first distribution flow passage (111) in the second direction (Y), the single flow passage (122) communicating with Q2 of the second base flow passages (221) and satisfying: M>P>Q1≥Q2。
  8. 8. the fuel cell plate structure according to any one of claims 1-7, characterized in that the flow field (10) is arranged centrally symmetrically with respect to the geometrical centre point of the plate body.
  9. 9. The fuel cell plate structure according to claim 8, wherein, The flow field (10) comprises an air inlet distribution area (1), a reaction flow field area (2) and an air outlet distribution area (3) which are sequentially arranged along a first direction (X), the air inlet distribution area (1) comprises a first air inlet distribution area (11), a second air inlet distribution area (12) and a third air inlet distribution area (13) which are arranged side by side along a second direction (Y), the reaction flow field area (2) comprises a first reaction flow field area (21), a second reaction flow field area (22) and a third reaction flow field area (23) which are arranged side by side along the second direction (Y), the air outlet distribution area (3) comprises a first air outlet distribution area (31), a second air outlet distribution area (32) and a third air outlet distribution area (33) which are arranged side by side along the second direction (Y), Along the first direction (X), the first reactive flow field region (21) is located between the first inlet distribution region (11) and the first outlet distribution region (31), the second reactive flow field region (22) is located between the second inlet distribution region (12) and the second outlet distribution region (32), the third reactive flow field region (23) is located between the third inlet distribution region (13) and the third outlet distribution region (33), wherein, The first air inlet distribution area (11) and the third air outlet distribution area (33) are arranged in a central symmetry mode relative to the geometric center point of the polar plate body; the second air inlet distribution area (12) and the first air outlet distribution area (31) are arranged in a central symmetry mode relative to the geometric center point of the polar plate body; the third inlet distribution area (13) and the second outlet distribution area (32) are arranged in a central symmetry mode relative to the geometric center point of the polar plate body.
  10. 10. A single fuel cell is characterized by comprising a membrane electrode, an anode plate and a cathode plate, wherein the cathode plate, the membrane electrode and the anode plate are sequentially stacked to form the single fuel cell, and the anode plate and/or the cathode plate are/is of the structure of the fuel cell polar plate in any one of claims 1-9.

Description

Fuel cell polar plate structure and fuel cell unit cell Technical Field The invention relates to the technical field of fuel cells, in particular to a fuel cell polar plate structure and a fuel cell unit cell. Background The proton exchange membrane fuel cell has the advantages of high power generation efficiency, environmental friendliness and the like, and has wide application prospect. The efficient water thermal management system has important significance for improving the performance of the fuel cell and prolonging the service life of the fuel cell. The bipolar plate is a key component of the proton exchange membrane fuel cell, and the flow field on the bipolar plate can uniformly distribute gas to the gas diffusion layer on one hand, so that the current density and the temperature generated by the electrochemical reaction are uniformly distributed, and on the other hand, the generated water is discharged out of the electric pile in time, so that the reasonable design of the flow field is very important for improving the performance of the water heat management of the fuel cell. At present, common flow fields of proton exchange membrane fuel cells mainly comprise parallel flow fields, serpentine flow fields, interdigital flow fields and the like. The flow channel is discontinuous, the gas is blocked in the flowing process, the gas is forced to diffuse to the surrounding flow channels, the process is favorable for improving the gas utilization rate and the power density, but the gas is forced to diffuse through the diffusion layer to generate larger pressure drop, if the gas is too large, the forced convection can damage the gas diffusion layer to reduce the cell performance, the parallel flow field is widely applied to the fuel cell, but the smaller pressure drop and the larger branch flow channels enable the reactant gas in the whole flow field to flow unevenly, the mass transfer of the reactant gas in the flow field is poor, the output power of the cell is seriously affected, and when the flow channel of the parallel flow field is too wide, the problems of uneven gas distribution, difficult water drainage and the like are easily caused, the water drainage effect of the snake-shaped flow field is better, but the flow channel is long and the pressure drop is large, the gas is mainly subjected to electrochemical reaction at the front section of the snake-shaped flow channel, and the reactant gas at the rear section of the flow channel is insufficient, so that the performance of the fuel cell is affected. Therefore, it is needed to provide a flow field structure of a fuel cell to overcome the problem of uneven gas distribution after gas enters the flow field of the reaction area of the fuel cell, thereby improving the performance of the fuel cell. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to provide a fuel cell plate structure, which has a relatively uniform pressure and supply of the gas entering the first reactive flow field from the first gas inlet distribution area, so that the reaction rate of the first reactive flow field is relatively uniform, and the energy conversion efficiency is improved. The fuel cell polar plate structure comprises a polar plate body, a flow field, a first gas inlet distribution area and a first reaction flow field area, wherein the two ends of the polar plate body along a first direction are respectively provided with a gas inlet and a gas outlet, the flow field is arranged on the polar plate body and is positioned between the gas inlet and the gas outlet, the flow field is respectively communicated with the gas inlet and the gas outlet, the flow field comprises a first gas inlet distribution area and a first reaction flow field area which are sequentially arranged along the first direction, the first gas inlet distribution area is used for enabling gas to uniformly flow into the first reaction flow field area from the gas inlet, the first gas inlet distribution area comprises a plurality of first distribution flow channels which are arranged side by side along a second direction, the first reaction flow field area comprises a plurality of first basic flow channels which are arranged side by side along the second direction, the first direction and the second direction are mutually perpendicular, two of the first distribution flow channels are respectively a first flow channel and a second flow channel, the length of the first flow channel is smaller than the length of the second flow channel, the first flow channel is communicated with N first flow channels, and M is more than or equal to N basic flow channels are communicated with the first flow channels. According to the fuel cell polar plate structure provided by the embodiment of the invention, different numbers of the first basic flow channels can be matched according to different length