A fuel cell bipolar plate flow field structure
By employing a cross-arranged anode and cathode flow channel structure and an edge split flow channel design in the bipolar plate flow field of the fuel cell, the problems of low reaction efficiency and poor weldability in traditional flow field structures are solved, thereby improving the reaction efficiency and welding yield of the fuel cell stack and extending its service life.
Patent Information
- Application Number
- CN202521064682.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-28
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-05-28
AI Technical Summary
Traditional fuel cell bipolar plate flow field structures suffer from low reaction efficiency, poor weldability, and high production costs. In particular, the meandering flow field is prone to problems during welding, affecting the consistency and lifespan of the fuel cell stack.
A flow field structure for a fuel cell bipolar plate is designed, wherein the flow channels of the anode and cathode flow fields are arranged in an intersecting manner. The straight-line flow channels of the anode meandering flow field unit and the cathode meandering flow field unit overlap, and the oblique flow channels intersect. Combined with the edge split channel design, this ensures uniform gas distribution and effective discharge of reaction water, and improves weldability.
It improves the reaction efficiency and welding yield of the fuel cell stack, reduces production costs, ensures the uniformity and consistency of fuel cell stack performance, and extends the service life of the fuel cell stack.
Smart Images
Figure CN224683098U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fuel cell technology, and in particular to a bipolar plate flow field structure for a fuel cell. Background Technology
[0002] Hydrogen fuel cells, as a highly efficient and clean energy conversion device, have received widespread attention in recent years. Their stack structure typically consists of an upper end plate, upper insulating plate, upper current collector, core, lower current collector, lower insulating plate, lower end plate, and fasteners. The core is the core power generation unit of the fuel cell stack, composed of a certain number of bipolar plates and membrane electrode assemblies (MEAs). Generally, the higher the stack power, the more cores are required. Bipolar plates play a crucial role in the fuel cell stack, providing pathways for hydrogen, air, and coolant, and guiding fluids from the piping into the reaction zone of the bipolar plate, ensuring uniform in-plane fluid distribution. Furthermore, the three chambers of the bipolar plate need to be separated and non-interfering, while the bipolar plate also provides rigid support for the entire core and has electrical conductivity. The MEA is the site of the electrochemical reaction.
[0003] Traditional bipolar plate flow field structures mainly include three types: direct current (DC) field, meandering flow field, and serpentine flow field. The DC field has a relatively small pressure drop, which is beneficial for the uniform distribution of reactant gas and coolant. However, its gas residence time is short, resulting in low gas utilization, and its ability to drive water out through the pressure difference in the flow channel is also relatively weak. In contrast, the serpentine flow field has a longer single flow channel and a larger pressure drop, which is detrimental to the uniformity of current density and easily leads to in-plane power generation deviation, thus affecting the consistency and even lifespan of the fuel cell stack. The meandering flow field can be seen as a compromise between the DC and serpentine flow fields, incorporating the advantages of both while inheriting their disadvantages, with performance falling between the two.
[0004] In traditional technologies, the cathode and anode flow field structures of meandering bipolar plates are typically aligned, using a ridge-to-ridge, groove-to-groove configuration. This design presents several problems: the membrane electrode corresponding to the groove exhibits a stronger reaction, while the membrane electrode corresponding to the ridge suffers from relatively weaker reactions due to gas diffusion difficulties caused by pressure. Furthermore, the activation zone of this flow field is usually formed by welding, but due to the meandering nature of the flow field, various problems can easily arise during the welding process, which not only affects production efficiency but also increases production costs. Utility Model Content
[0005] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a bipolar plate flow field structure for fuel cells, which can improve the reaction efficiency of the fuel cell stack, enhance the weldability of the reaction zone, enhance the drainage capacity of the plate, and thus improve the life of the fuel cell stack.
[0006] To solve the above-mentioned technical problems, this utility model provides a fuel cell bipolar plate flow field structure, comprising: The anode flow field includes multiple parallel anode flow channels, with anode ridges between adjacent anode flow channels; each anode flow channel includes several anode meandering flow field units; The cathode flow field includes multiple parallel cathode flow channels, with cathode ridges between adjacent cathode flow channels; each cathode flow channel includes several cathode meandering flow field units. The anode meandering flow field unit and the cathode meandering flow field unit both include alternating horizontal and vertical flow channels and oblique flow channels; the length of the horizontal and vertical flow channel of the anode meandering flow field unit is equal to the length of the horizontal and vertical flow channel of the cathode meandering flow field unit and they are arranged in an overlapping manner; the oblique flow channel of the anode meandering flow field unit and the oblique flow channel of the cathode meandering flow field unit are arranged in an intersecting manner.
[0007] In one embodiment of this utility model, the meandering angle of the anode meandering flow field unit is greater than that of the cathode meandering flow field unit. The meandering angle refers to the angle between the projection of the flow channel in the horizontal direction and the actual direction of the flow channel, specifically ranging from 130° to 160° for the anode meandering flow field unit and from 100° to 130° for the cathode meandering flow field unit.
[0008] In one embodiment of this utility model, the amplitude of the anode meandering flow field unit is smaller than the amplitude of the cathode meandering flow field unit.
[0009] In one embodiment of this utility model, the lateral distance of the anode meandering flow field unit is equal to the lateral distance of the cathode meandering flow field unit.
[0010] In one embodiment of the present invention, the anode meandering flow field unit comprises a first anode straight flow channel, a first anode oblique flow channel, a second anode straight flow channel, and a second anode oblique flow channel connected in sequence, and the first anode oblique flow channel and the second anode oblique flow channel are symmetrically arranged.
[0011] In one embodiment of the present invention, the cathode meandering flow field unit comprises a first cathode straight DC channel, a first cathode oblique flow channel, a second cathode straight DC channel, and a second cathode oblique flow channel connected in sequence, and the first cathode oblique flow channel and the second cathode oblique flow channel are symmetrically arranged.
[0012] In one embodiment of this utility model, an anode edge flow channel is provided at the edge of the anode flow field. The anode edge flow channel includes a first anode edge branch channel and a second anode edge branch channel. The first anode edge branch channel is arranged parallel to the anode meandering flow field unit, and the second anode edge branch channel is connected to the first anode edge branch channel.
[0013] In one embodiment of the present invention, an anode edge ridge is provided between the first anode edge distribution channel and the second anode edge distribution channel.
[0014] In one embodiment of the present invention, a cathode edge flow channel is provided at the edge of the cathode flow field. The cathode edge flow channel includes a first cathode edge branch channel, a second cathode edge branch channel, and a third cathode edge branch channel. The first cathode edge branch channel is arranged parallel to the cathode meandering flow field unit, and the second cathode edge branch channel and the third cathode edge branch channel are both connected to the first cathode edge branch channel.
[0015] In one embodiment of this utility model, cathode edge ridges are provided between the first cathode edge distribution channel and the second cathode edge distribution channel, as well as between the second cathode edge distribution channel and the third cathode edge distribution channel.
[0016] Compared with the prior art, the above-mentioned technical solution of this utility model has the following beneficial effects: (1) The flow field structure of the bipolar plate of the fuel cell described in this utility model has the non-straight flow channels of the anode and cathode flow fields in a cross-shaped, non-ridge-to-ridge form, which can enhance the gas entry into the catalytic layer of the membrane electrode, thereby enhancing the electrochemical reaction at the ridge and improving the reaction efficiency. At the same time, this structure is also conducive to the discharge of water generated by the membrane electrode reaction at the ridge, further optimizing the reaction environment. The straight DC channel of the anode flow field is directly opposite to the straight DC channel of the cathode flow field, which makes the welding process during bipolar plate forming more convenient. Straight welds are easier to weld, and the welding yield and efficiency will be significantly improved. The straight flow channels have strong weldability, which can effectively reduce the probability of welding abnormalities and reduce the defect rate, thereby reducing production costs and improving production efficiency.
[0017] (2) The edge channel design of this utility model sets multiple channels in the cathode edge channel and the anode edge channel respectively, so that there is no reaction blind zone in the channel at the edge position, avoiding the occurrence of local gas shortage, thereby further improving the reaction efficiency of the entire stack and ensuring the uniformity and consistency of the stack performance. Attached Figure Description
[0018] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. Figure 1 This is a schematic diagram of the flow field structure of the fuel cell bipolar plate in a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the anode flow field structure of this utility model; Figure 3This is a schematic diagram of the cathode flow field of the bipolar plate flow field structure of the fuel cell of this utility model. Figure 4 This is a partial structural schematic diagram of the anode meandering flow field unit of this utility model; Figure 5 This is a partial structural schematic diagram of the cathode meandering flow field unit of this utility model; Figure 6 A schematic diagram of the structure of the anode edge flow channel in the anode flow field of this utility model; Figure 7 A schematic diagram of the structure of the cathode flow field of this utility model with a cathode edge flow channel; Figure 8 This is a schematic diagram showing the combination of the anode edge flow channel and the cathode edge flow channel of this utility model; Reference numerals: 1. Anode flow field; 2. Cathode flow field; 11. Anode flow channel; 12. Anode ridge; 21. Cathode flow channel; 22. Cathode ridge; 110. First anode straight-flow channel; 111. First anode oblique flow channel; 112. Second anode straight-flow channel; 113. Second anode oblique flow channel; 210. First cathode straight-flow channel; 211. First cathode oblique flow channel; 212. Second cathode straight-flow channel; 213. Second cathode oblique flow channel; 10. Anode edge flow channel; 101. First anode edge branch channel; 102. Second anode edge branch channel; 103. Anode edge ridge; 20. Cathode edge branch channel; 201. First cathode edge branch channel; 202. Second cathode edge branch channel; 203. Third cathode edge branch channel; 204. Cathode edge ridge. Detailed Implementation
[0019] 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 and implement the present invention. However, the embodiments are not intended to limit the present invention.
[0020] Reference Figure 1-3 As shown, this utility model provides a bipolar plate flow field structure for a fuel cell, comprising: The anode flow field 1 includes multiple parallel anode flow channels 11, with anode ridges 12 between adjacent anode flow channels 11; each anode flow channel 11 includes several anode meandering flow field units. Cathode flow field 2; it includes multiple parallel cathode flow channels 21, with cathode ridges 22 between adjacent cathode flow channels 21; each cathode flow channel 21 includes several cathode meandering flow field units; The anode meandering flow field unit and the cathode meandering flow field unit both include alternating horizontal and vertical flow channels and oblique flow channels; the length b of the horizontal and vertical flow channel of the anode meandering flow field unit is equal to the length b' of the horizontal and vertical flow channel of the cathode meandering flow field unit and they are arranged in an overlapping manner; the oblique flow channel of the anode meandering flow field unit and the oblique flow channel of the cathode meandering flow field unit are arranged in an intersecting manner.
[0021] The overlap of the straight-line direct current channels of the anode flow field 1 and the cathode flow field 2 ensures efficient reaction of the reactant gas at the straight-line direct current channel position, and makes the welding process more convenient. The straight weld seam is easier to weld, improving the welding yield and efficiency. The cross arrangement of the oblique flow channels of the anode flow field 1 and the cathode flow field 2 enhances the gas entry into the catalytic layer of the membrane electrode, improves the electrochemical reaction efficiency of the ridge, and facilitates the discharge of reaction-generated water, reducing water accumulation in the flow field and optimizing the reaction environment.
[0022] In this embodiment, the meandering angle d of the anode meandering flow field unit is greater than the meandering angle d' of the cathode meandering flow field unit. The meandering angle refers to the angle between the projection of the flow channel in the horizontal direction and the actual direction of the flow channel. Specifically, the meandering angle of the anode meandering flow field unit is between 130° and 160°, and the meandering angle of the cathode meandering flow field unit is between 100° and 130°, meaning the cathode flow field 2 is steeper than the anode flow field 1. By designing the cathode flow field 2 to be relatively steep, it facilitates rapid mass transfer of the reacting gas and the discharge of reacting water; the anode flow field 2, being relatively gentle, facilitates the rapid discharge of reacting water that has permeated into the anode through the membrane electrode at the cathode outlet (i.e., the anode inlet), thereby reducing water accumulation in the flow field and further optimizing the mass transfer process.
[0023] In this embodiment, the straight channel can be regarded as having a meandering angle of 180°. The smaller the angle, the steeper the channel; the larger the angle, the gentler the channel.
[0024] Specifically, the amplitude 'a' of the anode meandering flow field unit is smaller than the amplitude 'a' of the cathode meandering flow field unit. The amplitude value of the anode meandering flow field unit is between 1 mm and 2 mm, and the amplitude value of the cathode meandering flow field unit is between 2 mm and 5 mm.
[0025] The lateral distance c of the anode meandering flow field unit is equal to the lateral distance c' of the cathode meandering flow field unit. In this embodiment, the lateral distance c of the anode meandering flow field unit and the lateral distance c' of the cathode meandering flow field unit are both between 10mm and 20mm.
[0026] like Figure 4As shown, the anode meandering flow field unit comprises a first anode straight-flow channel 110, a first anode oblique-flow channel 111, a second anode straight-flow channel 112, and a second anode oblique-flow channel 113 connected in sequence, with the first anode oblique-flow channel 111 and the second anode oblique-flow channel 113 arranged symmetrically. The lengths of the first anode straight-flow channel 110 and the second anode straight-flow channel 112 are between 1mm and 5mm. The first anode straight-flow channel 110 and the second anode straight-flow channel 112 are welding positions, and the influence of the weld length on the weld strength needs to be considered during the design, generally between 1-3mm.
[0027] like Figure 5 As shown, the cathode meandering flow field unit comprises a first cathode straight flow channel 210, a first cathode oblique flow channel 211, a second cathode straight flow channel 212, and a second cathode oblique flow channel 213 connected in sequence, and the first cathode oblique flow channel 211 and the second cathode oblique flow channel 213 are symmetrically arranged.
[0028] like Figure 6 As shown, an anode edge channel 10 is provided at the edge of the anode flow field 1. The anode edge channel 10 includes a first anode edge branch channel 101 and a second anode edge branch channel 102. The first anode edge branch channel 101 is arranged parallel to the anode meandering flow field unit, and the second anode edge branch channel 102 is connected to the first anode edge branch channel 101. The design of the anode edge channel reduces the reaction blind zone at the edge and avoids local gas shortage. By reasonably setting the anode edge branch channel, the gas supply at the edge is ensured, further improving the reaction efficiency of the entire fuel cell stack.
[0029] An anode edge ridge 103 is provided between the first anode edge channel 101 and the second anode edge channel 102. The anode edge ridge 103 enhances the structural stability of the anode edge channel 10.
[0030] like Figure 7 As shown, a cathode edge flow channel 20 is provided at the edge of the cathode flow field 2. The cathode edge flow channel 20 includes a first cathode edge branch channel 201, a second cathode edge branch channel 202, and a third cathode edge branch channel 203. The first cathode edge branch channel 201 is arranged parallel to the cathode meandering flow field unit, and the second cathode edge branch channel 202 and the third cathode edge branch channel 203 are both connected to the first cathode edge branch channel 201. The design of the cathode edge flow channel 20 reduces the reaction blind zone at the edge and avoids the occurrence of local gas shortage.
[0031] Cathode edge ridges 204 are provided between the first cathode edge branch channel 201 and the second cathode edge branch channel 202, and between the second cathode edge branch channel 202 and the third cathode edge branch channel 203. The provision of cathode edge ridges 204 enhances the structural stability of the cathode edge branch channel 20.
[0032] In this embodiment, both the first anode edge diversion channel 101 and the second anode edge diversion channel 102 include a direct anode edge channel and an oblique anode edge channel, with the oblique anode edge channels symmetrically arranged on both sides of the direct anode edge channel. Similarly, the cathode edge channel 201, the second cathode edge diversion channel 202, and the third cathode edge diversion channel 203 each include a direct cathode edge channel and an oblique cathode edge channel, with the oblique cathode edge channels symmetrically arranged on both sides of the direct cathode edge channel.
[0033] When the anode flow field 1 and the cathode flow field 2 are combined, the corresponding relationship is as follows: Figure 8 As shown, the first cathode edge branch channel 201 corresponds to the straight DC channel in the anode meandering flow field unit, the second cathode edge branch channel 202 corresponds to the straight DC channel in the anode meandering flow field unit, and the third cathode edge branch channel 203 corresponds to the anode edge DC channel of the first anode edge branch channel 101. By rationally arranging the correspondence of the edge branch channels, there are no reaction blind zones in the flow channels at the edge positions, thereby further improving the reaction efficiency of the entire fuel cell stack and ensuring the uniformity and consistency of the stack performance.
[0034] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A bipolar plate flow field structure for a fuel cell, characterized in that: include: The anode flow field includes multiple parallel anode flow channels, with anode ridges between adjacent anode flow channels; each anode flow channel includes several anode meandering flow field units; The cathode flow field includes multiple parallel cathode flow channels, with cathode ridges between adjacent cathode flow channels; each cathode flow channel includes several cathode meandering flow field units. The anode meandering flow field unit and the cathode meandering flow field unit both include alternating horizontal and vertical flow channels and oblique flow channels; the length of the horizontal and vertical flow channel of the anode meandering flow field unit is equal to the length of the horizontal and vertical flow channel of the cathode meandering flow field unit and they are arranged in an overlapping manner; the oblique flow channel of the anode meandering flow field unit and the oblique flow channel of the cathode meandering flow field unit are arranged in an intersecting manner.
2. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: The snaking angle of the anode snaking flow field unit is greater than that of the cathode snaking flow field unit.
3. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: The amplitude of the anode meandering flow field unit is smaller than the amplitude of the cathode meandering flow field unit.
4. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: The lateral distance of the anode meandering flow field unit is equal to the lateral distance of the cathode meandering flow field unit.
5. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: The anode meandering flow field unit comprises a first anode straight flow channel, a first anode oblique flow channel, a second anode straight flow channel, and a second anode oblique flow channel connected in sequence, and the first anode oblique flow channel and the second anode oblique flow channel are symmetrically arranged.
6. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: The cathode meandering flow field unit comprises a first cathode straight flow channel, a first cathode oblique flow channel, a second cathode straight flow channel, and a second cathode oblique flow channel connected in sequence, and the first cathode oblique flow channel and the second cathode oblique flow channel are symmetrically arranged.
7. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: An anode edge flow channel is provided at the edge of the anode flow field. The anode edge flow channel includes a first anode edge branch channel and a second anode edge branch channel. The first anode edge branch channel is arranged parallel to the anode meandering flow field unit, and the second anode edge branch channel is connected to the first anode edge branch channel.
8. The bipolar plate flow field structure for a fuel cell according to claim 7, characterized in that: An anode edge ridge is provided between the first anode edge distribution channel and the second anode edge distribution channel.
9. The bipolar plate flow field structure for a fuel cell according to claim 1, characterized in that: The cathode flow field is provided with a cathode edge flow channel at its edge position. The cathode edge flow channel includes a first cathode edge branch channel, a second cathode edge branch channel, and a third cathode edge branch channel. The first cathode edge branch channel is arranged parallel to the cathode meandering flow field unit. The second cathode edge branch channel and the third cathode edge branch channel are both connected to the first cathode edge branch channel.
10. The bipolar plate flow field structure for a fuel cell according to claim 9, characterized in that: A cathode edge ridge is provided between the first cathode edge branch channel and the second cathode edge branch channel, as well as between the second cathode edge branch channel and the third cathode edge branch channel.