Fuel cell flow field plate
By designing baffles on the flow field plate of the fuel cell to create turbulence, the problems of low airflow velocity and weak mass transfer capacity in the parallel flow field are solved, thereby improving the performance of the fuel cell and the product water discharge capacity, and adapting to different operating conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-11
- Publication Date
- 2026-03-10
AI Technical Summary
In parallel flow fields, the airflow velocity is low, the flow is in a laminar state, and the airflow direction is orthogonal and perpendicular to the mass transfer direction, resulting in weak mass transfer capacity and difficulty in removing product water, which affects the performance of fuel cells.
A fuel cell flow field plate is designed, which uses multiple baffles to form turbulence, including a first guide surface and a second guide surface. The baffles turbulent the airflow, enhance the airflow velocity, and improve the heat and mass transfer capability through the asymmetrical arrangement of the guide surfaces.
It enhances gas mass transfer capacity, improves fuel cell performance, effectively removes product water, alleviates the "flooding" phenomenon, and adapts to different operating conditions.
Smart Images
Figure CN121642013A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of fuel cell technology, and particularly relates to a fuel cell flow field plate. BACKGROUND
[0002] Proton exchange membrane fuel cell is an electrochemical reaction power generation device, which can directly convert chemical energy in fuel into electrical energy, and has obvious advantages of higher energy conversion efficiency than traditional internal combustion engine, and its product is only water, and has advantages of high power density, no pollution, low noise and the like, and has wide application prospect in new energy vehicle and distributed power generation and the like. In the working process of the fuel cell, the flow field plate mainly plays the roles of electric conduction, transport and distribution of reaction gas, and at the same time, water generated in the reaction process is discharged in time to avoid "water flooding".
[0003] An improper flow field plate design can cause uneven gas distribution, and product water cannot be discharged in time, thereby affecting the heat and mass transfer characteristics and performance of the fuel cell. At present, the basic forms of the flow field include parallel flow field, serpentine flow field and interdigital flow field. The parallel flow field has advantages of simple structure, easy processing, low pressure drop and uniform gas distribution, and is one of the common flow field types in the proton exchange membrane fuel cell.
[0004] The parallel flow field has relatively low gas flow speed, and the flow is generally in a laminar state, and the gas flow direction is orthogonal to the mass transfer direction, which can easily lead to problems of weak mass transfer capacity and difficult discharge of product water. SUMMARY
[0005] Therefore, it is necessary to provide a fuel cell flow field plate to solve the problems of the parallel flow field, such as relatively low gas flow speed, flow generally in a laminar state, and gas flow direction orthogonal to mass transfer direction, which can easily lead to problems of weak mass transfer capacity and difficult discharge of product water.
[0006] The embodiment of the present application provides a fuel cell flow field plate, which comprises a flow field plate and a plurality of baffles; the flow field plate is provided with a flow channel, and the top of the flow channel is open; the plurality of baffles are arranged in the flow channel in sequence along the extension direction of the flow channel, the side of the plurality of baffles away from the opening is a first flow guide surface, and the side of the plurality of baffles facing the opening is a second flow guide surface, so that the gas flowing through the flow channel forms a turbulent flow when passing through the baffles.
[0007] Further, the plurality of baffles each comprises a first part and a second part, the opposite sides of the first part and the second part are each a plane parallel to the extension direction of the flow channel, the plane portions between the first part and the second part are butt-jointed, the first part is arranged away from the opening, and the opposite sides of the first part and the second part form the first flow guide surface and the second flow guide surface respectively.
[0008] Further, the first flow guide surface comprises a first arc surface and a first inclined surface connected in sequence along the extension direction of the flow channel, the first arc surface is tangent to the plane, the vertical distance from the first arc surface to the opening gradually increases and then gradually decreases along the extension direction of the flow channel, and the vertical distance from the first inclined surface to the opening gradually decreases along the extension direction of the flow channel. The second flow guide surface comprises a second arc surface and a second inclined surface connected in sequence along the extension direction of the flow channel, the second arc surface is tangent to the plane, the vertical distance from the second arc surface to the opening gradually decreases and then gradually increases along the extension direction of the flow channel, and the vertical distance from the second inclined surface to the opening gradually increases along the extension direction of the flow channel.
[0009] Further, the first flow guide surface and the second flow guide surface are asymmetrically arranged on both sides of the plane.
[0010] Further, the length of the first flow guide surface along the extension direction of the flow channel is greater than the length of the second flow guide surface along the extension direction of the flow channel.
[0011] Further, the angle between the first inclined surface and the plane is 20°-30°, and the angle between the second inclined surface and the plane is 10°-20°.
[0012] Further, the distance from the plane to the opening of the flow channel is 1 / 2-3 / 5 of the height of the flow channel, the ratio of the length of the stop block along the extension direction of the flow channel to the height of the flow channel is 1-2:1, the ratio of the width of the stop block to the width of the flow channel is 0-1:1, and the length of the inclined surface of the stop block is 2 / 5-1 / 2 of the height of the flow channel.
[0013] Further, a plurality of stop blocks can be arranged at equal intervals or non-equal intervals along the extension direction of the flow channel.
[0014] Further, the flow field plate comprises a bottom plate and a plurality of ridge plates, the ridge plates are connected to the bottom plate, the ridge plates are arranged on one side of the bottom plate, and the ridge plates and the bottom plate form a cavity and leave a gas inlet and a gas outlet to form a flow channel for gas flow.
[0015] Compared with the prior art, when the reaction gas passes through the stop blocks arranged in the flow channel, the stop blocks disturb the flow of the reaction gas, specifically, the flow rate of the gas flowing through the first flow guide surface increases, which is beneficial to the discharge of product water; at the same time, the gas flowing through the second flow guide surface can enhance the heat and mass transfer capacity perpendicular to the gas flow direction, effectively improve the mass transfer efficiency limited by the fact that the gas flow direction and the electrochemical reaction direction are perpendicular to each other, and strengthen the transport of the reaction gas. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 This is a schematic diagram of the overall structure of the fuel cell flow field plate provided in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the arrangement of the intermediate baffle in the flow channel; Figure 3 This is a schematic diagram of the flow channel distribution; Figure 4 for Figure 1 A structural schematic diagram of the middle block from one viewpoint; Figure 5 for Figure 1 A structural schematic diagram of the middle block from another perspective. Detailed Implementation
[0017] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.
[0018] like Figures 1-2 As shown in the figure, an embodiment of the present invention provides a fuel cell flow field plate, including a flow field plate 100 and a plurality of baffles 200; a flow channel 10a is formed on the flow field plate 100, and the top of the flow channel 10a is open; the plurality of baffles 200 are arranged sequentially in the flow channel 10a along the extension direction of the flow channel 10a, the side of the plurality of baffles 200 away from the opening is a first guide surface 210, and the side of the plurality of baffles 200 facing the opening is a second guide surface 220, so that the gas flowing through the flow channel 10a forms turbulence when passing through the baffles 200.
[0019] In practice, by setting multiple baffles 200 in the flow channel 10a, when the reactant gas passes through the baffles 200, the baffles 200 disturb the flow of the reactant gas. Specifically, the flow velocity of the gas flowing through the first guide surface 210 increases, which is beneficial to the discharge of product water. At the same time, the gas flowing through the second guide surface 220 can enhance the heat and mass transfer capacity perpendicular to the gas flow direction, effectively improve the mass transfer efficiency limited by the gas flow direction being perpendicular to the electrochemical reaction direction, and strengthen the transport of reactant gas.
[0020] In this embodiment, the flow field plate 100 mainly functions to conduct electricity, transport and distribute the reaction gas, and at the same time, it discharges the water generated during the reaction in a timely manner to prevent "flooding". Specifically, the flow field plate 100 has a flow channel 10a formed on it, with an opening at the top of the flow channel 10a and the opening of the flow channel 10a being close to the gas diffusion layer.
[0021] In one embodiment, the flow field plate 100 includes a base plate 110 and a plurality of ridge plates 120. The ridge plates 120 are connected to the base plate 110 and are arranged on one side of the base plate 110. The ridge plates 120 and the base plate 110 form a cavity and have a gas inlet 10b and a gas outlet 10c to form a flow channel 10a for gas flow.
[0022] It is understandable that the number of flow channels 10a is determined according to specific needs. At the same time, the flow field plate 100 can also be replaced by other shapes of structures, as long as flow channels 10a can be formed.
[0023] In this embodiment, multiple baffles 200 are arranged sequentially in the flow channel 10a along its extension direction. The side of the multiple baffles 200 away from the opening is a first guide surface 210, and the side of the multiple baffles 200 facing the opening is a second guide surface 220, so that the gas flowing through the flow channel 10a forms turbulence when passing through the baffles 200. The material of the baffles 200 is the same as the material of the flow field plate 100.
[0024] In one embodiment, each of the multiple baffles 200 includes a first part and a second part. The opposite sides of the first part and the second part are both planes parallel to the extension direction of the flow channel 10a. The planes between the first part and the second part are connected. The first part is disposed away from the opening. The opposite sides of the first part and the second part respectively form a first guide surface 210 and a second guide surface 220.
[0025] Among them, such as Figure 4 As shown, the first guide surface 210 includes a first arcuate surface 211 and a first inclined surface 212 connected sequentially along the extension direction of the flow channel 10a. The first arcuate surface 211 is tangent to the plane. The vertical distance from the first arcuate surface 211 to the opening gradually increases and then gradually decreases along the extension direction of the flow channel 10a. The vertical distance from the first inclined surface 212 to the opening gradually decreases along the extension direction of the flow channel 10a.
[0026] like Figure 5 As shown, the second guide surface 220 includes a second arcuate surface 221 and a second inclined surface 222 connected sequentially along the extension direction of the flow channel 10a. The second arcuate surface 221 is tangent to the plane. The vertical distance from the second arcuate surface 221 to the opening gradually decreases and then gradually increases along the extension direction of the flow channel 10a. The vertical distance from the second inclined surface 222 to the opening gradually increases along the extension direction of the flow channel 10a.
[0027] In one embodiment, the first guide surface 210 and the second guide surface 220 are asymmetrically arranged on opposite sides of a plane. With this arrangement, the airflow velocities through the first guide surface 210 and the second guide surface 220 are different, creating a pressure difference between the two airflows, thereby enhancing gas mass transfer.
[0028] In this embodiment, the length of the first guide surface 210 along the extension direction of the flow channel 10a is greater than the length of the second guide surface 220 along the extension direction of the flow channel 10a.
[0029] The angle between the first inclined plane 212 and the plane is 20°~30°, and the angle between the second inclined plane 222 and the plane is 10°~20°.
[0030] The distance from the plane to the opening of the flow channel 10a is 1 / 2 to 3 / 5 of the height of the flow channel 10a. The ratio of the length of the baffle 200 along the extension direction of the flow channel 10a to the height of the flow channel 10a is 1 to 2:1. The ratio of the width of the baffle 200 to the width of the flow channel 10a is 0 to 1:1. The length of the inclined surface of the baffle 200 is 2 / 5 to 1 / 2 of the height of the flow channel 10a.
[0031] like Figure 3 As shown, in one embodiment, a plurality of baffles 200 are arranged at equal intervals along the extension direction of the flow channel 10a. Of course, in other embodiments, the plurality of baffles 200 may also be arranged at non-equal intervals.
[0032] Example: The flow channel 10a of the fuel cell anode flow field plate 100 is 30 mm long, 1 mm wide, and 1 mm high, with a spacing of 1 mm between adjacent flow channels 10a. The cathode flow field plate 100 is based on the anode flow field plate 100, with teardrop-shaped baffles 200 arranged at equal intervals. Each baffle 200 is 1 mm long, with a preset angle of 30° between the first inclined surface 212 and the plane, and a preset angle of 15° between the second inclined surface 222 and the plane. The lengths of the first and second inclined surfaces 212 are set to half the height of the flow channel 10a, i.e., 0.5 mm. The spacing between the baffles 200 is 2 mm. The operating conditions of the fuel cell are set as follows: temperature 80℃, humidified hydrogen and humidified air used for the anode and cathode respectively, relative humidity of 70% for both anode and cathode gases, stoichiometric ratios of 2 and 4 for the anode and cathode respectively, and back pressure of 0 for both anode and cathode.
[0033] Compared with existing technologies: 1. The biomimetic teardrop-shaped baffle 200 and flow field plate 100 design proposed in this embodiment of the invention effectively enhances the gas mass transfer capability under high current density conditions, thus significantly improving battery performance. 2. The biomimetic teardrop-shaped baffle 200 and flow field plate 100 design proposed in this embodiment of the invention can accelerate the gas flow rate in the fuel cell, which is conducive to the discharge of product water and can effectively alleviate the "flooding" phenomenon. 3. The biomimetic teardrop-shaped baffle 200 flow field plate 100 design proposed in this embodiment of the invention can be adapted to different working conditions by adjusting the number and structural parameters of the baffle 200.
[0034] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.
Claims
1. A fuel cell flow field plate characterized by, The flow field plate and a plurality of blocks are included, the flow channel is formed on the flow field plate, the top of the flow channel is open; a plurality of blocks are arranged in the flow channel along the extension direction of the flow channel, the first flow guide surface is away from the opening side of a plurality of blocks, and the second flow guide surface is opposite to the opening side of a plurality of blocks, so that the gas flowing through the flow channel forms a turbulent flow when passing through the block.
2. The fuel cell flow field plate of claim 1, wherein A plurality of blocks each include a first part and a second part, the opposite side of the first part and the second part is a plane parallel to the extension direction of the flow channel, the plane part between the first part and the second part is butt joint, the first part is away from the opening, and the opposite side of the first part and the second part forms the first flow guide surface and the second flow guide surface respectively.
3. The fuel cell flow field plate of claim 2, wherein, The first flow guide surface includes a first arc surface and a first inclined surface connected in sequence along the extension direction of the flow channel, the first arc surface is tangent to the plane, the vertical distance from the first arc surface to the opening gradually increases and then gradually decreases along the extension direction of the flow channel, and the vertical distance from the first inclined surface to the opening gradually decreases along the extension direction of the flow channel. The second flow guide surface includes a second arc surface and a second inclined surface connected in sequence along the extension direction of the flow channel, the second arc surface is tangent to the plane, the vertical distance from the second arc surface to the opening gradually decreases and then gradually increases along the extension direction of the flow channel, and the vertical distance from the second inclined surface to the opening gradually increases along the extension direction of the flow channel.
4. The fuel cell flow field plate of claim 3, wherein, The first flow guide surface and the second flow guide surface are asymmetrically arranged on both sides of the plane.
5. The fuel cell flow field plate of claim 4, wherein, The length of the first flow guide surface along the extension direction of the flow channel is greater than the length of the second flow guide surface along the extension direction of the flow channel.
6. The fuel cell flow field plate of claim 5, wherein, The included angle between the first inclined surface and the plane is 20°-30°, and the included angle between the second inclined surface and the plane is 10°-20°.
7. The fuel cell flow field plate of claim 2, wherein The distance from the plane to the opening of the flow channel is 1 / 2-3 / 5 of the height of the flow channel, the ratio of the length of the block along the extension direction of the flow channel to the height of the flow channel is 1-2:1, the ratio of the width of the block to the width of the flow channel is 0-1:1, and the length of the inclined surface of the block is 2 / 5-1 / 2 of the height of the flow channel.
8. The fuel cell flow field plate of claim 1, wherein, A plurality of blocks can be arranged at equal intervals or non-equal intervals along the extension direction of the flow channel.
9. The fuel cell flow field plate of claim 1, wherein, The flow field plate includes a bottom plate and a plurality of ridge plates, the ridge plate is connected with the bottom plate, the ridge plate is arranged on one side of the bottom plate, the ridge plate and the bottom plate form a cavity and leave a gas inlet and a gas outlet to form a flow channel for gas flow.