Fuel cell graphite bipolar plate fluid access region bridge structure

Abstract

The application relates to a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure, which comprises a bridge pier and a bridge deck; the bridge pier is connected with the bridge deck and is located above the bridge deck; the bridge deck comprises an embossed reinforcing part which is concave relative to the upper surface of the bridge deck. The embossed reinforcing part is a concave rhombus or a strip. Compared with the prior art, the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure can effectively improve the pressure bearing capacity of the bridge area of the graphite bipolar plate under the premise of meeting certain flow resistance requirements by arranging the embossed reinforcing part.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of graphite bipolar plates, in particular to a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure. BACKGROUND

[0002] Fuel cell bipolar plates are mainly divided into two technical routes, namely metal bipolar plates and graphite bipolar plates. Metal bipolar plates usually use a substrate with a thickness of 75-100 microns, which is formed by stamping, and has the advantage of being ultra-thin. Since metal is a continuous phase material and has sufficient rigidity, the bridge portion of the fluid inlet and outlet area of the bipolar plate can support the pressure of the seal. With the increasing demand for volume power density of fuel cells, graphite bipolar plates are also being designed to be thinner. Since graphite material is a non-continuous phase and has poor rigidity, the support capacity of the bridge portion of the fluid inlet and outlet area of the bipolar plate is poor when the design is thinned. With the thinning design of the graphite bipolar plate, if the deformation of the bridge is too large when the seal is compressed, it will cause problems such as insufficient inlet gas supply, inconsistent performance between stack pieces, etc. If the bridge of the bipolar plate is crushed during service, it will cause serious problems such as seal leakage, flow resistance surge, uneven gas distribution, and water blockage. The existing technology focuses on the influence of the bridge area on fluid distribution. For example, the utility model patent CN 214411257 U discloses a fuel cell gas flow field plate, bipolar plate and fuel cell, which can reduce the generation of turbulent flow and vortex when gas passes through the bridge slot into the connecting channel and the flow field slot, and make the gas uniformly dispersed to each part of the connecting channel and the flow field slot, to ensure the efficiency of the fuel cell. For example, the utility model patent CN213936250U discloses a fuel cell gas inlet and outlet mechanism and a fuel cell. The fuel cell gas inlet and outlet mechanism provided by the utility model can improve the uniformity of gas flow distribution and reduce the flow resistance compared with the Z-shaped flow channel. However, the existing technology does not have any research on increasing the strength of the bridge. How to improve the pressure-bearing capacity of the bridge area of the graphite bipolar plate under the premise of meeting certain flow resistance requirements is a problem that needs to be solved. SUMMARY

[0003] The purpose of the present application is to overcome the defects of the prior art and provide a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure. The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in the present application can effectively improve the pressure-bearing capacity of the bridge area of the graphite bipolar plate under the premise of meeting certain flow resistance requirements by setting the embossing reinforcement part.

[0004] The purpose of the present application can be achieved by the following technical solutions:

[0005] The purpose of the present application is to provide a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure, which comprises a pier and a bridge deck; the pier and the bridge deck are connected, and the pier is located above the bridge deck; the bridge deck comprises an embossed reinforcement portion recessed downward relative to the upper surface of the bridge deck.

[0006] Optionally, the embossed reinforcement portion is a downwardly recessed rhombus.

[0007] Further optionally, the embossed reinforcement portion is a downwardly recessed square.

[0008] Optionally, the embossed reinforcement portion is a downwardly recessed strip.

[0009] Preferably, the depth of the embossed reinforcement portion is 0.1-0.2 mm.

[0010] Preferably, the spacing between adjacent piers is 2.0-2.5 mm.

[0011] Preferably, the height of the pier is 0.3-0.4 mm.

[0012] Preferably, the width of the pier is 2.0 mm.

[0013] Preferably, the thickness of the bridge deck is 0.3 mm.

[0014] Preferably, a plurality of embossed reinforcement portions are provided and arranged in an array.

[0015] Preferably, the spacing between the edges of adjacent embossed reinforcement portions is 0.3 mm.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1) The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure provided by the present application can effectively improve the pressure-bearing capacity of the bridge area of the graphite bipolar plate by setting an embossed reinforcement portion and through the periodic density change of the material, while meeting certain flow resistance requirements.

[0018] 2) The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure provided by the present application can significantly enhance the bridge area of the bipolar plate through structural design and adjustment of the microstructure of the bridge area of the bipolar plate. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Figure 1 is a front view of a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to an embodiment of the present application.

[0020] Figure 2It is a bottom view schematic diagram of a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in Example 1 of the present application.

[0021] Figure 3 It is a front view schematic diagram of a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in Example 2 of the present application.

[0022] Figure 4 It is a bottom view schematic diagram of a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in Example 2 of the present application.

[0023] Figure 5 It is a front view schematic diagram of a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in Comparative Example 1, 2 of the present application.

[0024] Figure 6 It is a bottom view schematic diagram of a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in Comparative Example 1, 2 of the present application.

[0025] Figure 7 It is a schematic diagram of a bridge area of a fuel cell graphite bipolar plate fluid inlet and outlet area.

[0026] Wherein:

[0027] 1, bridge pier, 2, bridge deck, 3, embossed reinforcement. DETAILED DESCRIPTION

[0028] The present application will be described in detail below with reference to the accompanying drawings and specific examples. In the technical solution, if the component model, material name, connection structure and other features are not explicitly stated, they are considered as common technical features disclosed in the prior art.

[0029] As shown in the schematic diagram of a bridge area of a fuel cell graphite bipolar plate fluid inlet and outlet area. Figure 7

[0030] Example 1

[0031] As shown in the schematic diagram of a bridge area of a fuel cell graphite bipolar plate fluid inlet and outlet area. Figures 1-2 In this embodiment, a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure is provided, which comprises a bridge pier 1 and a bridge deck 2; the bridge pier 1 and the bridge deck 2 are connected, and the bridge pier 1 is located above the bridge deck 2; the bridge deck 2 comprises a plurality of arrayed embossed reinforcement parts 3 recessed downward relative to the upper surface of the bridge deck 2, the projection of the embossed reinforcement part 3 in the front view direction is a downward recessed square, and one diagonal of the square is parallel to the side of the bridge pier 1, in other words, the embossed reinforcement part 3 is a staggered recessed structure formed by the unenhanced parts on the bridge deck 2 at 45° and 135° to the horizontal direction.

[0032] ​In this embodiment, the side length of the embossed reinforcement part 3 is 0.3 mm, the depth of the concave embossed reinforcement part 3 is 0.2 mm, the spacing between adjacent bridge piers 1 is 2.0 mm, the height of the bridge pier 1 is 0.4 mm, the width of the bridge pier 1 is 2.0 mm, and the thickness of the bridge deck 2 is 0.3 mm. Multiple embossed reinforcement parts 3 are provided, and the multiple embossed reinforcement parts 3 are arranged in an array. The spacing between the edges of adjacent embossed reinforcement parts 3 is 0.3 mm, and the thickness of the unreinforced part is the thickness of the bridge deck 2.

[0033] In this embodiment, the bridge structure of the fluid inlet and outlet area of ​​the fuel cell graphite bipolar plate collapses to a depth of 0.02 mm under a pressure of 6 N / mm.

[0034] Example 2

[0035] like Figures 3-4 As shown, in this embodiment, a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure is provided, and the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure includes a bridge pier 1 and a bridge deck 2; the bridge pier 1 and the bridge deck 2 are connected, and the bridge pier 1 is located above the bridge deck 2; the bridge deck 2 includes a plurality of array-type embossed reinforcement parts 3 that are concave relative to the upper surface of the bridge deck 2, and the embossed reinforcement parts 3 are concave strips. Except for the top and bottom embossed reinforcement parts 3, the projections of which in the front view direction are trapezoidal, the projections of the middle embossed reinforcement parts 3 in the front view direction are all parallelograms, and the long sides of the parallelograms are 45° to the side sides of the bridge pier 1. In other words, the embossed reinforcement parts 3 are formed by alternating the unreinforced parts on the bridge deck 2 that are 45° to the horizontal direction to form a concave structure.

[0036] In this embodiment, the length of the short side of the parallelogram-shaped embossed reinforcement portion 3 is 0.3 mm, the depth of the concave embossed reinforcement portion 3 is 0.1 mm, the spacing between adjacent piers 1 is 2.5 mm, the height of the pier 1 is 0.3 mm, the width of the pier 1 is 2.0 mm, and the thickness of the bridge deck 2 is 0.3 mm. Multiple embossed reinforcement portions 3 are provided, and the multiple embossed reinforcement portions 3 are arranged in an array. The spacing between the edges of adjacent embossed reinforcement portions 3 is 0.3 mm, and the thickness of the unreinforced part is the thickness of the bridge deck 2.

[0037] In this embodiment, the bridge structure of the fluid inlet and outlet area of ​​the fuel cell graphite bipolar plate collapses to a depth of 0.01 mm under a pressure of 5 N / mm.

[0038] Comparative Example 1

[0039] like Figures 5-6 As shown, in this embodiment, a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure is provided, and the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure includes a bridge pier 1 and a bridge deck 2; the bridge pier 1 and the bridge deck 2 are connected, and the bridge pier 1 is located above the bridge deck 2.

[0040] In the present comparative example, no embossing enhancement part is provided, and the dimensions of the piers 1 and the bridge deck 2 are the same as in Example 1, i.e. the distance between adjacent piers 1 is 2.0 mm, the height of the piers 1 is 0.4 mm, the width of the piers 1 is 2.0 mm, and the thickness of the bridge deck 2 is 0.3 mm.

[0041] Under the action of a pressure of 6 N / mm, the collapse depth of the bridge of the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in the present example is 0.06 mm.

[0042] Comparative Example 2

[0043] As shown in Figures 5-6 The present example provides a fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure, which comprises piers 1 and a bridge deck 2; the piers 1 and the bridge deck 2 are connected, and the piers 1 are located above the bridge deck 2.

[0044] In the present comparative example, no embossing enhancement part is provided, and the dimensions of the piers 1 and the bridge deck 2 are the same as in Example 2, i.e. the distance between adjacent piers 1 is 2.5 mm, the height of the piers 1 is 0.3 mm, the width of the piers 1 is 2.0 mm, and the thickness of the bridge deck 2 is 0.3 mm.

[0045] Under the action of a pressure of 5 N / mm, the collapse depth of the bridge of the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in the present example is 0.05 mm.

[0046] By comparing Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2, the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure of the present application has a significantly greater strength than the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure in the comparative examples without the embossing enhancement part, which shows that the embossing enhancement part has a significant effect on enhancing the bridge of the bipolar plate.

[0047] The principle by which the fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure of the present application can produce structural enhancement is that the periodic density change of the material causes the bridge area of the bipolar plate to produce structural enhancement. The periodic density change of the material is due to the difference in bulk density between the concave embossing enhancement part 3 and the unenhanced part, and the periodic change in bulk density can significantly improve the pressure-bearing capacity of the bridge area.

[0048] The foregoing description of the embodiments has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed. Modifications and variations are possible in light of the above teachings or can be acquired from practice of the application. As well, the description is presented in the context of the preferred embodiments as a number of alternatives. It is not intended to limit the application to the precise form described.

Claims

1. A fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure, characterized in that: The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure comprises a bridge pier (1) and a bridge deck (2); The bridge pier (1) is connected to the bridge deck (2), and the bridge pier (1) is located above the bridge deck (2); The bridge deck (2) comprises an embossed reinforcement portion (3) that is concave relative to the upper surface of the bridge deck (2); A plurality of embossing reinforcement portions (3) are provided, and the plurality of embossing reinforcement portions (3) are arranged in an array; By providing the embossed reinforcement portion (3), the pressure bearing capacity of the bridge region of the graphite bipolar plate is effectively improved under the premise of meeting certain flow resistance requirements through periodic density changes of the material; The depth of the concave portion (3) is 0.1-0.2 mm; The thickness of the bridge deck (2) is 0.3 mm.

2. A fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to claim 1, characterized in that: The distance between the edges of adjacent embossed reinforcement portions (3) is 0.3 mm.

3. The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to claim 1, characterized in that: The embossed reinforcement portion (3) is in the shape of a concave rhombus.

4. The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to claim 1, characterized in that: The embossed reinforcement portion (3) is in the shape of a concave strip.

5. The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to claim 1, characterized in that: The spacing between adjacent piers (1) is 2.0-2.5 mm.

6. The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to claim 1, characterized in that: The height of the bridge pier (1) is 0.3-0.4 mm.

7. The fuel cell graphite bipolar plate fluid inlet and outlet area bridge structure according to claim 1, characterized in that: The width of the bridge pier (1) is 2.0 mm.

Images