Streamlined transition zone structure and pole plate

Abstract

The application provides a streamlined transition zone structure suitable for a polar plate of a fuel cell, comprising a first streamlined part, a second streamlined part and a third streamlined part, the second streamlined part is arranged between the first streamlined part and the third streamlined part, the first streamlined part and the second streamlined part are arranged close to the inlet / outlet of the polar plate; the first streamlined part comprises a plurality of independently arranged first ridges, the plurality of first ridges are arranged to be curved towards the second streamlined part; the second streamlined part comprises a plurality of independently arranged second ridges, the plurality of second ridges are arranged in a linear shape; the third streamlined part comprises a plurality of independently arranged third ridges, the plurality of third ridges are arranged to be curved towards the second streamlined part; the flow area of the third streamlined part is greater than the flow area of the second streamlined part, and the flow area of the second streamlined part is greater than the flow area of the first streamlined part. The application also provides a polar plate. The structure of the application is uniform in fluid distribution and small in pressure drop.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a streamlined transition region structure and electrode plate. Background Technology

[0002] Hydrogen fuel cells can directly convert the chemical energy in hydrogen and oxygen into electrical energy, without being limited by the Carnot cycle, and have a high conversion rate, making them a highly efficient energy conversion device. At the same time, the only byproduct of hydrogen fuel cells is water, which is clean, pollution-free, and has zero carbon emissions, making it an ideal new energy carrier.

[0003] A fuel cell stack is formed by connecting individual cells (cells) in series. Each cell consists of a membrane electrode assembly (MEA) and bipolar plates. Currently, the two main types of bipolar plates for hydrogen fuel cells are graphite plates and metal plates. Grooves, or flow channels, are typically created on the surface of the bipolar plates using molding / stamping techniques. The flow inside the cell (including the flow of hydrogen, air, and water) is confined within these grooves, thus forming the internal flow field of the cell. The distribution of this flow has a significant impact on the cell's performance. Currently, in fuel cell bipolar plate design, transition zones are often used to distribute the flow. However, while these transition zones serve their function, they can also lead to excessive pressure drop across the bipolar plates.

[0004] The plates of proton exchange membrane fuel cells are developing towards smaller dimensions and more three-dimensional structures. However, the current fuel cell plate flow channel design is flawed, easily leading to uneven flow distribution, increased pressure loss on the plates, decreased reactant diffusion and mass transfer capabilities, and reduced reactant utilization, ultimately resulting in decreased fuel cell performance. Summary of the Invention

[0005] Therefore, to address the problems of unreasonable electrode channel design in existing fuel cells, which easily leads to uneven flow distribution, increased pressure loss on the electrode, decreased diffusion and mass transfer capacity of reactants, and reduced utilization of reactants, thus resulting in decreased fuel cell performance, this invention provides a streamlined transition zone structure and electrode. The streamlined transition zone structure of this application can effectively control flow distribution, ensuring uniform flow distribution while effectively reducing pressure drop.

[0006] To achieve the above objectives, in one aspect, embodiments of the present invention provide a streamlined transition zone structure suitable for the electrode plate of a fuel cell, including a first streamlined portion, a second streamlined portion and a third streamlined portion, wherein the second streamlined portion is disposed between the first streamlined portion and the third streamlined portion, and the first streamlined portion and the second streamlined portion are disposed near the inlet / outlet of the electrode plate;

[0007] The first streamlined section includes multiple independently arranged first ridges, which are curved toward the second streamlined section; the second streamlined section includes multiple sets of independently arranged second ridges, which are arranged in a linear shape; the third streamlined section includes multiple independently arranged third ridges, which are curved toward the second streamlined section.

[0008] The flow area of ​​the third streamlined section is greater than that of the second streamlined section, and the flow area of ​​the second streamlined section is greater than that of the first streamlined section.

[0009] In a preferred embodiment, the first streamline portion is connected to the flow channel of the electrode plate and the inlet / outlet of the electrode plate, respectively; the second streamline portion is connected to the flow channel of the electrode plate and the inlet / outlet of the electrode plate, respectively; and the third streamline portion is connected to the flow channel of the electrode plate and the inlet / outlet of the electrode plate, respectively.

[0010] In a preferred embodiment, the ends of each first ridge near the flow channel of the electrode plate are on the same horizontal line; a first transition channel is formed between two adjacent first ridges, and the first transition channel is connected to the flow channel of the electrode plate.

[0011] In a preferred embodiment, each group of second ridges includes an independently arranged second sub-ridge and a second branch ridge. The second sub-ridge is arranged close to the first streamline portion, and the length of the second sub-ridge is shorter than the length of the second branch ridge.

[0012] In a preferred embodiment, the ends of the flow channels of the first ridge and the second ridge near the flow channels of the electrode plate are on the same horizontal line; the second sub-ridge and the second branch ridge are respectively inclined to the flow channels of the electrode plate.

[0013] In a preferred embodiment, the second ridge and the second branch ridge are inclined, and the end of the flow channel of the second ridge near the electrode plate and the end of the flow channel of the second branch ridge near the electrode plate are on the same horizontal line.

[0014] In a preferred embodiment, a second transition channel is formed between adjacent second ridges and second branch ridges, and the second transition channel is connected to the flow channel of the electrode plate.

[0015] In a preferred embodiment, the third ridge furthest from the second streamline portion is designated as the third starting ridge, and the length of the multiple third ridges increases sequentially from the third starting ridge; a third transition channel is formed between two adjacent third ridges, and the third transition channel is connected to the flow channel of the electrode plate.

[0016] In a preferred embodiment, the width of the third transition channel is greater than the width of the second transition channel, and the width of the second transition channel is greater than the width of the first transition channel.

[0017] In a preferred embodiment, the flow rates of the first transition channel, the second transition channel, and the third transition channel are the same.

[0018] In a preferred embodiment, both the inlet and outlet of the electrode plate are provided with the streamlined transition zone structure.

[0019] On the other hand, embodiments of the present invention also provide an electrode plate suitable for fuel cells, wherein the electrode plate is provided with the streamlined transition region structure.

[0020] This invention proposes a streamlined transition zone structure. By having a first ridge bent towards a second streamlined portion, a second ridge in a linear configuration, and a third ridge bent towards the second streamlined portion, the fluid flow within the transition zone structure is made approximately the same as the actual fluid flow. This ensures that the flow rate in all areas of the transition zone is divided into essentially equal portions, thereby guaranteeing uniform fluid distribution while effectively reducing the pressure drop in the electrode plates. With this streamlined transition zone structure, the fluid flow distribution is uniform, and the pressure drop in the electrode plates is reduced to 16 kPa, significantly lower than the 40 kPa pressure drop of existing structures. Simultaneously, the diffusion and mass transfer capabilities and utilization rate of the reactants are effectively improved, resulting in better fuel cell performance. This invention also features a low-cost, economical, and practical structure that is easy to install and suitable for mass production. Attached Figure Description

[0021] 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.

[0022] Figure 1 This is a schematic diagram of a streamlined transition region structure according to an embodiment of the present invention;

[0023] Figure 2 Application of the present invention Figure 1 A schematic diagram of the structure of the electrode plate with a streamlined transition zone.

[0024] 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

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Currently, in existing fuel cell electrode structures, the inlet is at the top and the outlet at the bottom, with the flow channels in the transition zone arranged horizontally in parallel. Fluid enters from the inlet, passes through the distribution in the transition zone, and then enters the lower flow channel. The fluid has a lateral flow velocity within the flow channels. Because the flow channels in the transition zone are arranged horizontally in parallel, they impede fluid flow, leading to uneven fluid distribution, increased pressure loss on the electrode, decreased diffusion and mass transfer capacity of reactants, and reduced reactant utilization, ultimately degrading fuel cell performance. Therefore, this application provides a streamlined transition zone structure and electrode to solve the aforementioned technical problems.

[0031] On the one hand, such as Figures 1 to 2 As shown, this embodiment of the invention provides a streamlined transition zone structure suitable for the electrode plate 100 of a fuel cell, including a first streamlined section 10, a second streamlined section 20 and a third streamlined section 30. The second streamlined section 20 is disposed between the first streamlined section 10 and the third streamlined section 30. The first streamlined section 10 and the second streamlined section 20 are disposed near the inlet / outlet of the electrode plate 100.

[0032] The first streamlined section 10 includes multiple independently arranged first ridges 11, which are bent toward the second streamlined section 20; the second streamlined section 20 includes multiple sets of independently arranged second ridges 21, which are arranged in a linear shape; the third streamlined section 30 includes multiple independently arranged third ridges 31, which are bent toward the second streamlined section 20.

[0033] The flow area of ​​the third streamlined section 30 is larger than that of the second streamlined section 20, and the flow area of ​​the second streamlined section 20 is larger than that of the first streamlined section 10. This configuration effectively ensures uniform flow distribution and reduces pressure drop.

[0034] In this embodiment, the bending direction and degree of the first ridge 11 are consistent with the flow angle and direction of the fluid in the electrode plate, which effectively ensures uniform flow distribution and reduces pressure drop; the bending direction and degree of the third ridge 31 are consistent with the flow angle and direction of the fluid in the electrode plate, which further effectively ensures uniform flow distribution and reduces pressure drop. In this embodiment, the first ridge, the second ridge, and the third ridge are all integrally formed with the electrode plate.

[0035] In a preferred embodiment, the first streamlined portion 10 is connected to the flow channel 101 of the electrode plate 100 and the inlet 102 / outlet 103 of the electrode plate 100, respectively; the second streamlined portion 20 is connected to the flow channel 101 of the electrode plate 100 and the inlet 102 / outlet 103 of the electrode plate 100, respectively; and the third streamlined portion 30 is connected to the flow channel 101 of the electrode plate 100 and the inlet 102 / outlet 103 of the electrode plate 100, respectively.

[0036] In a preferred embodiment, the ends of each first ridge 11 near the flow channel 101 of the electrode plate 100 are on the same horizontal line; a first transition channel 12 is formed between two adjacent first ridges 11, and the first transition channel 12 is connected to the flow channel 101 of the electrode plate 100. This can effectively ensure uniform flow distribution and reduce pressure drop.

[0037] In a preferred embodiment, each group of second ridges 21 includes independently arranged second sub-ridges 211 and second branch ridges 212. The second sub-ridges 211 are located close to the first streamline portion 10, and the length of the second sub-ridges 211 is shorter than the length of the second branch ridges 212. This arrangement ensures the distance between the second sub-ridges 211 and the second branch ridges 212, thereby effectively ensuring uniform flow distribution and reducing pressure drop, while also facilitating the processing of the second sub-ridges 211 and the second branch ridges 212.

[0038] In a preferred embodiment, the ends of the first ridge 11 near the flow channel 101 of the electrode plate 100 and the ends of the second ridge 21 near the flow channel 101 of the electrode plate 100 are on the same horizontal line; the second branch ridge 211 and the second sub-ridge 212 are respectively inclined to the flow channel 101 of the electrode plate 100. This ensures that the flow angle and direction of the second transition channel are consistent with the flow of the fluid in the electrode plate, which can effectively ensure uniform flow distribution and reduce pressure drop. If the ends of the first ridge 11 near the flow channel 101 of the electrode plate 100 and the ends of the second ridge 21 near the flow channel 101 of the electrode plate 100 are not on the same horizontal line (e.g., at different heights), the flow distribution of the fluid in the electrode plate will be uneven and the pressure drop will be large.

[0039] In a preferred embodiment, the second ridge 211 and the second branch ridge 212 are inclined, and the end of the second ridge 211 near the flow channel 101 of the electrode plate 100 and the end of the second branch ridge 212 near the flow channel 101 of the electrode plate 100 are on the same horizontal line. This can effectively ensure uniform flow distribution and reduce pressure drop.

[0040] In a preferred embodiment, a second transition channel 22 is formed between adjacent second ridges 211 and second branch ridges 212, and the second transition channel 22 is connected to the flow channel 101 of the electrode plate 100.

[0041] In a preferred embodiment, the third ridge 31 furthest from the second streamline section 20 is designated as the third starting ridge A, and the lengths of the multiple third ridges 31 increase sequentially from the third starting ridge A. A third transition channel 32 is formed between two adjacent third ridges 31, and the third transition channel 32 is connected to the flow channel 101 of the electrode plate 100. This ensures that the flow angle and direction of the third transition channel are consistent with those of the fluid in the electrode plate, thereby effectively guaranteeing uniform flow distribution and reducing pressure drop.

[0042] In a preferred embodiment, the width of the third transition channel 32 is greater than the width of the second transition channel 22, and the width of the second transition channel 22 is greater than the width of the first transition channel 12. This effectively ensures uniform flow distribution and reduces pressure drop.

[0043] In a preferred embodiment, the flow rates of the first transition channel 12, the second transition channel 22, and the third transition channel 32 are the same.

[0044] In a preferred embodiment, both the inlet 102 and the outlet 103 of the electrode plate 100 are provided with the streamlined transition zone structure.

[0045] On the other hand, embodiments of the present invention also provide an electrode plate 100 suitable for fuel cells, wherein the electrode plate 100 is provided with the streamlined transition region structure.

[0046] In this embodiment, both the inlet 102 and the outlet 103 of the electrode plate 100 are provided with the streamlined transition zone structure, which can better ensure the distribution of fluid in the electrode plate and make the fuel cell have better performance.

[0047] This invention proposes a streamlined transition zone structure. By having a first ridge bent towards a second streamlined portion, a second ridge in a linear configuration, and a third ridge bent towards the second streamlined portion, the fluid flow within the transition zone structure is made approximately the same as the actual fluid flow. This ensures that the flow rate in all areas of the transition zone is divided into essentially equal portions, thereby guaranteeing uniform fluid distribution while effectively reducing the pressure drop in the electrode plates. With this streamlined transition zone structure, the fluid flow distribution is uniform, and the pressure drop in the electrode plates is reduced to 16 kPa, significantly lower than the 40 kPa pressure drop of existing structures. Simultaneously, the diffusion and mass transfer capabilities and utilization rate of the reactants are effectively improved, resulting in better fuel cell performance. This invention also features a low-cost, economical, and practical structure that is easy to install and suitable for mass production.

[0048] 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 streamlined transition zone structure, characterized in that, An electrode plate suitable for a fuel cell includes a first streamlined portion, a second streamlined portion, and a third streamlined portion, wherein the second streamlined portion is disposed between the first streamlined portion and the third streamlined portion, and the first streamlined portion and the second streamlined portion are located near the inlet / outlet of the electrode plate. The first streamlined section includes multiple independently arranged first ridges, which are curved toward the second streamlined section; the second streamlined section includes multiple sets of independently arranged second ridges, which are arranged in a linear shape; the third streamlined section includes multiple independently arranged third ridges, which are curved toward the second streamlined section. The flow area of ​​the third streamlined section is larger than the flow area of ​​the second streamlined section, and the flow area of ​​the second streamlined section is larger than the flow area of ​​the first streamlined section. The first streamline portion is connected to the flow channel of the electrode plate and the inlet / outlet of the electrode plate, respectively; the second streamline portion is connected to the flow channel of the electrode plate and the inlet / outlet of the electrode plate, respectively; the third streamline portion is connected to the flow channel of the electrode plate and the inlet / outlet of the electrode plate, respectively. A first transition channel is formed between two adjacent first ridges. Each group of the second ridges includes independently set second sub-ridges and second branch ridges, with a second transition channel formed between adjacent second sub-ridges and second branch ridges. A third transition channel is formed between two adjacent third ridges. The flow rates of the first transition channel, the second transition channel, and the third transition channel are the same.

2. The streamlined transition zone structure according to claim 1, characterized in that, The ends of the flow channels of each of the first ridges near the electrode plate are on the same horizontal line; the first transition channel is connected to the flow channels of the electrode plate.

3. The streamlined transition zone structure according to claim 2, characterized in that, The second ridge is positioned close to the first streamlined portion, and the length of the second ridge is shorter than the length of the second branch ridge.

4. The streamlined transition zone structure according to claim 3, characterized in that, The ends of the first ridge and the second ridge near the flow channel of the electrode plate are on the same horizontal line; the second sub-ridge and the second branch ridge are respectively inclined to the flow channel of the electrode plate.

5. The streamlined transition zone structure according to claim 4, characterized in that, The second ridge and the second branch ridge are inclined, and the end of the flow channel of the second ridge near the electrode plate and the end of the flow channel of the second branch ridge near the electrode plate are on the same horizontal line.

6. The streamlined transition region structure according to claim 3, characterized in that, The second transition channel is connected to the flow channel of the electrode plate.

7. The streamlined transition zone structure according to claim 6, characterized in that, The third ridge, which is furthest from the second streamline section, is designated as the third starting ridge, and the length of the multiple third ridges increases sequentially from the third starting ridge; the third transition channel is connected to the flow channel of the electrode plate.

8. The streamlined transition zone structure according to claim 7, characterized in that, The width of the third transition channel is greater than the width of the second transition channel, and the width of the second transition channel is greater than the width of the first transition channel.

9. An electrode plate, characterized in that, Suitable for fuel cells, wherein the electrode plate is provided with a streamlined transition region structure as described in any one of claims 1 to 8.

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