Polar plate flow channel structure with backflow inhibition function and application thereof

Abstract

The application provides a polar plate flow channel structure with a backflow inhibiting function, which is suitable for a fuel cell polar plate and comprises a first port, a flow channel body and a second port connected in sequence; one side wall of the flow channel body is provided with a first ladder, and the first ladder comprises multiple first steps connected in sequence; the other side wall of the flow channel body is provided with a second ladder, and the second ladder comprises multiple second steps connected in sequence; the first steps and the second steps are staggered in the direction from the first port to the second port. The application also provides an application of the polar plate flow channel structure with the backflow inhibiting function. The structure can greatly reduce the backflow speed of fluid, avoid the backflow phenomenon, increase the disturbance of gas in the flow channel, thereby effectively increasing the amount of gas flowing to the diffusion layer and effectively improving the reaction utilization rate of the gas.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell technology, in particular to a bipolar plate flow channel structure with backflow inhibition function and application thereof. BACKGROUND

[0002] In the face of increasingly stringent domestic and even global tail gas emission standards and future energy crisis, major automobile manufacturers are developing low-emission new energy technologies to adapt to this trend, among which fuel cell vehicles are one of the fields that major automobile manufacturers are vigorously developing. Fuel cells have many advantages such as cleanliness and high efficiency, and are attracting more and more attention from people.

[0003] The bipolar plate, as the core component of the fuel cell, plays an important role in distributing gas, conducting electricity and heat, and draining water in the fuel cell. The performance of the bipolar plate is largely dependent on the flow field structure. At present, the flow field generally includes traditional flow field and new type flow field; the conventional traditional flow field has straight channel, serpentine and interdigital type, etc., and the new type flow field includes bionic flow field, spiral flow field and 3D flow field, etc. The straight channel flow field is the most basic flow field, generally has many parallel flow channels, the flow field distance is short, the inlet and outlet pressure loss is small, the parallel channels are beneficial to the uniform distribution of the reaction gas and the cooling water in the channel, can realize the uniform distribution of the current density and the battery temperature, and the structure is simple and easy to process. However, the reaction gas stays in the straight channel flow field for a short time, the gas utilization rate is low, the gas flow rate is relatively low, the generated water cannot be discharged in time, and water blocking is easy to occur. Moreover, the bipolar plate of the high-power stack structure is often larger in size and longer in flow channel, and is more likely to have the problems of insufficient gas, back gas and large gas pressure drop and outlet gas backflow. SUMMARY

[0004] Therefore, the bipolar plate flow channel structure with backflow inhibition function and application thereof are provided, which can greatly reduce the backflow speed of the fluid, avoid the backflow phenomenon, increase the disturbance of the gas in the flow channel, thereby effectively increasing the amount of gas flowing to the diffusion layer and effectively improving the reaction utilization rate of the gas.

[0005] To achieve the above-mentioned purpose, on one hand, the bipolar plate flow channel structure with backflow inhibition function is provided, which is suitable for the bipolar plate of the fuel cell and includes a first port, a flow channel body and a second port connected in sequence.

[0006] A first step is provided on one side wall of the flow channel body, the first step including multiple connected first steps; a second step is provided on the other side wall of the flow channel body, the second step including multiple connected second steps; the first step and the second step are staggered in the direction from the first port to the second port.

[0007] In a preferred embodiment, the direction from the first port to the second port is the low-resistance direction of the fluid, and the direction from the second port to the first port is the high-resistance direction of the fluid.

[0008] In a preferred embodiment, the corner of the first step is positioned opposite to the center of the step surface of the second step; the corner of the second step is positioned opposite to the center of the step surface of the first step.

[0009] In a preferred embodiment, the corner of the first step is ≥90°, and the corner of the second step is ≥90°.

[0010] In a preferred embodiment, the step surface of the first step is inclined downwards, with the direction from the first port to the second port as the orientation.

[0011] In a preferred embodiment, the step surface of the second step is inclined upwards, with the direction from the first port to the second port as the orientation.

[0012] In a preferred embodiment, the maximum vertical height of the first step is 0.12mm to 0.16mm, and the maximum vertical height of the second step is 0.12mm to 0.16mm.

[0013] In a preferred embodiment, the first port, the flow channel body, and the second port are integrally formed.

[0014] On the other hand, embodiments of the present invention also provide the application of the electrode flow channel structure with backflow suppression function, which can be applied to the electrode plates of fuel cells.

[0015] In a preferred embodiment, the electrode plates of the fuel cell are provided with a plurality of electrode flow channel structures having the function of suppressing backflow, and the plurality of electrode flow channel structures having the function of suppressing backflow are arranged in parallel with each other.

[0016] This invention, by incorporating a stepped structure on the sidewall of the flow channel, effectively increases the residence time of the reactant gas within the channel while retaining the advantages of a direct-flow flow path. This significantly improves gas utilization and prevents undergassing and backflow issues when used in high-power fuel cell stacks, thus avoiding problems such as large gas pressure drops and outlet gas backflow. The structure of this invention greatly reduces the fluid backflow velocity, preventing backflow and increasing gas turbulence within the flow channel. This effectively increases the amount of gas flowing towards the diffusion layer, thereby enhancing gas reaction utilization. Furthermore, this invention features a simple and aesthetically pleasing structure, low energy consumption, economic practicality, easy installation, and good manufacturability, making it suitable for use in fuel cell systems. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a front view of an electrode channel structure with backflow suppression function according to an embodiment of the present invention (where F is an abbreviation);

[0019] Figure 2 for Figure 1 A magnified view of the local structure at point F;

[0020] Figure 3 for Figure 1 A three-dimensional structural diagram of an electrode flow channel structure with backflow suppression function (where G is an abbreviation);

[0021] Figure 4 This is a front view of the electrode plate with a backflow suppression function according to an embodiment of the present invention.

[0022] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, top, bottom, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0027] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0028] Currently, the straight-channel flow field is the most basic flow field, generally featuring multiple parallel flow channels. It has short flow distances, low inlet and outlet pressure losses, and parallel channels facilitate uniform distribution of reactant gases and cooling water within the channels, achieving uniform current density and battery temperature distribution. Furthermore, it is simple in structure and easy to manufacture. However, the reactant gases have short residence times in the straight-channel flow field, resulting in low gas utilization, relatively low gas velocity, and the inability to promptly discharge generated water, easily leading to water blockage. Moreover, high-power fuel cell stacks often have larger electrode volumes and longer flow channels, making them more prone to under-gas and back-gas phenomena, leading to significant gas pressure drops and outlet gas backflow. To address these technical problems, this invention proposes an electrode flow channel structure with backflow suppression function and its application.

[0029] Specifically, such as Figures 1 to 3 As shown, an embodiment of the present invention provides a plate flow channel structure with backflow suppression function, which is suitable for fuel cell plate 100, including a first port 10, a flow channel body 20 and a second port 30 connected in sequence.

[0030] A first step 21 is provided on one side wall of the flow channel body 20. The first step 21 includes multiple connected first steps 211. A second step 22 is provided on the other side wall of the flow channel body 20. The second step 22 includes multiple connected second steps 221. The first step 211 and the second step 221 are staggered in the direction from the first port 10 to the second port 30.

[0031] By staggering the first step 211 and the second step 221 (meaning they are set opposite to each other and offset), the residence time of the reactant gas in the flow channel can be effectively increased while retaining the advantages of the direct flow channel, thus improving the gas utilization rate and effectively preventing fluid backflow at the second port.

[0032] In a preferred embodiment, the direction from the first port 10 to the second port 30 is the low-resistance direction of the fluid, and the direction from the second port 30 to the first port 10 is the high-resistance direction of the fluid. This improves gas utilization and prevents fluid backflow at the second port 30.

[0033] In a preferred embodiment, the corners 2111 of the first step 211 (including outer corner 2111A and inner corner 2111B) are positioned opposite to the center of the step surface 2211 of the second step 221; the corners 2212 of the second step 221 (including outer corner 2212C and inner corner 2212D) are positioned opposite to the center of the step surface 2112 of the first step 211. This arrangement ensures that the first step 211 and the second step 221 are staggered, further increasing the residence time of the reactant gas in the flow channel and effectively improving gas utilization.

[0034] In a preferred embodiment, the corners 2111 of the first step 211 (including the outer corner 2111A and the inner corner 2111B) are ≥90°, and the corners 2212 of the second step 221 (including the outer corner 2212C and the inner corner 2212D) are ≥90°. This ensures that the flow channel will not puncture the carbon paper pressed on it, while also effectively increasing the residence time of the reactant gas in the flow channel, thus improving gas utilization.

[0035] In this embodiment, an outer corner refers to a corner away from the center of the flow channel body, and an inner corner refers to a corner close to the center of the flow channel body.

[0036] In a preferred embodiment, the step surface 2112 of the first step 211 is inclined downwards along the direction from the first port 10 to the second port 30. This ensures that the corners of the first step 211 remain rounded, preventing the flow channel from puncturing the carbon paper pressed on it, while also effectively increasing the residence time of the reactant gas in the flow channel and improving the gas utilization rate.

[0037] In a preferred embodiment, the step surface 2211 of the second step 221 is inclined upwards, with the direction from the first port 10 to the second port 30 as the orientation. This ensures that the corners of the second step 221 remain rounded, thus preventing the flow channel from puncturing the carbon paper pressed on it, while also effectively increasing the residence time of the reactant gas in the flow channel and improving the gas utilization rate.

[0038] In a preferred embodiment, the maximum vertical height of the first step 211 is 0.12mm to 0.16mm, and the maximum vertical height of the second step 221 is 0.12mm to 0.16mm. This ensures that, while retaining the advantages of the direct current path, the first step 211 and the second step 221 effectively suppress fluid backflow at the second port.

[0039] In a preferred embodiment, the first port 10, the flow channel body 20, and the second port 30 are integrally formed.

[0040] On the other hand, embodiments of the present invention also provide the application of the electrode flow channel structure with backflow suppression function, which can be applied to the electrode plates of fuel cells.

[0041] As a preferred embodiment, such as Figure 4 As shown, the electrode plate 100 of the fuel cell is provided with multiple electrode plate flow channel structures with backflow suppression function, and the multiple electrode plate flow channel structures with backflow suppression function are arranged in parallel with each other. The electrode plate flow channel structure with backflow suppression function of this application occupies less space, and for the same electrode plate specifications, more flow channel structures of this application can be set, which can further increase the gas flow rate in the flow channel and promote the effective gas reaction.

[0042] This invention, by incorporating a stepped structure on the sidewall of the flow channel, effectively increases the residence time of the reactant gas within the channel while retaining the advantages of a direct-flow flow path. This significantly improves gas utilization and prevents undergassing and backflow issues when used in high-power fuel cell stacks, thus avoiding problems such as large gas pressure drops and outlet gas backflow. The structure of this invention greatly reduces the fluid backflow velocity, preventing backflow and increasing gas turbulence within the flow channel. This effectively increases the amount of gas flowing towards the diffusion layer, thereby enhancing gas reaction utilization. Furthermore, this invention features a simple and aesthetically pleasing structure, low energy consumption, economic practicality, easy installation, and good manufacturability, making it suitable for use in fuel cell systems.

[0043] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A plate flow channel structure with backflow suppression function, characterized in that, Suitable for fuel cell plates, comprising a first port, a flow channel body, and a second port connected in sequence; A first step is provided on one side wall of the flow channel body, the first step including multiple connected first steps; a second step is provided on the other side wall of the flow channel body, the second step including multiple connected second steps; the first step and the second step are staggered in the direction from the first port to the second port; The corner of the first step is positioned opposite to the center of the step surface of the second step; the corner of the second step is positioned opposite to the center of the step surface of the first step. The corner of the first step is ≥90°, and the corner of the second step is ≥90°; With the direction from the first port to the second port as the orientation, the step surface of the first step is inclined downward; the step surface of the second step is inclined upward. The direction from the first port to the second port is the low-resistance direction of the fluid, and the direction from the second port to the first port is the high-resistance direction of the fluid.

2. The electrode channel structure with backflow suppression function according to claim 1, characterized in that, The maximum vertical height of the first step is 0.12mm to 0.16mm, and the maximum vertical height of the second step is 0.12mm to 0.16mm.

3. The electrode channel structure with backflow suppression function according to claim 1, characterized in that, The first port, the flow channel body, and the second port are integrally formed.

4. The application of the electrode flow channel structure with backflow suppression function as described in any one of claims 1 to 3, characterized in that, The electrode flow channel structure with backflow suppression function is applied to the electrode plates of fuel cells.

5. The application of the electrode channel structure with backflow suppression function according to claim 4, characterized in that, The fuel cell has multiple electrode flow channel structures with backflow suppression function on its electrode plates, and the multiple electrode flow channel structures with backflow suppression function are arranged in parallel with each other.

Images