阅读说明：本技术 一种用于质子交换膜燃料电池双极板的新型气体流道结构 (Novel gas flow channel structure for bipolar plate of proton exchange membrane fuel cell ) 是由 刘琦 徐豪 林哲 朱祖超 于 2021-09-13 设计创作，主要内容包括：本发明公开了一种用于质子交换膜燃料电池双极板的新型气体流道结构,所述质子交换膜燃料电池双极板主要包括阳极板和阴极板,气体流道结构均为截面形状是凹四边形的导流柱呈鱼鳞状交错排列方式构成,靠近流道入口处的导流柱三角翼指向气体流入方向,靠近流道出口处的一列导流柱三角翼指向气体流出方向,气体主体流道是由导流柱交错排列形成波纹状的波纹状流道,波纹状流道之间存在间隙流道。本发明可有效增强质子交换膜燃料电池双极板内反应气体分布均匀性,提高反应气体利用率,并有效预防或缓解水淹,使得质子交换膜燃料电池的性能得到提升。(The invention discloses a novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell, which mainly comprises an anode plate and a cathode plate, wherein the gas flow channel structure is formed by arranging guide columns with concave quadrilateral cross sections in a fish scale shape in a staggered manner, triangular wings of the guide columns close to an inlet of a flow channel point to the gas inflow direction, a row of triangular wings of the guide columns close to an outlet of the flow channel point to the gas outflow direction, a main gas flow channel is a corrugated flow channel formed by staggered arrangement of the guide columns, and gap flow channels are arranged among the corrugated flow channels. The invention can effectively enhance the distribution uniformity of the reaction gas in the bipolar plate of the proton exchange membrane fuel cell, improve the utilization rate of the reaction gas, and effectively prevent or relieve flooding, so that the performance of the proton exchange membrane fuel cell is improved.)

1. A novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell comprises a fuel cell, characterized in that the fuel cell is formed by stacking and assembling a plurality of single cells, the single cells comprise anode plates (1), cathode plates (2) and membrane electrodes (3), the anode plate (1) and the cathode plate (2) are matched in size and form a bipolar plate, the middle parts of the anode plate (1) and the cathode plate (2) are respectively provided with a square groove-shaped flow field, the anode plate (1) and the cathode plate (2) are both provided with a flow channel inlet (4) which penetrates through one corner of the square groove-shaped flow field, the anode plate (1) and the cathode plate (2) are both provided with a runner outlet (5) which penetrates through the square groove-shaped flow field and is distributed diagonally to the runner inlet (4), and a gas runner structure is arranged in the square groove-shaped flow field; the gas flow channel structure is formed by arranging guide columns (9) with concave quadrilateral cross sections in a fish scale staggered manner, wherein the guide columns (9) are longitudinally provided with multiple rows, the direction of the triangular wings of the guide columns (9) in the same row is the same, the directions of the triangular wings of the guide columns (9) in adjacent rows are opposite, one row of the guide columns (9) at the position close to the flow channel inlet (4) is close to the direction of the triangular wings of the guide columns (9) in the gas flow direction, one row of the guide columns (9) at the position close to the flow channel outlet (5) is close to the direction of the triangular wings of the guide columns (9) in the square groove-shaped flow field, the guide columns (9) in the square groove-shaped flow field are staggered to form multiple groups of transverse and parallel corrugated flow channels (10), the guide columns (9) in the square groove-shaped flow field are not mutually connected and are adjacent, and multiple gap flow channels (6) are formed between the corrugated flow channels (10), the square groove-shaped flow field is characterized in that the anode plate (1) and the cathode plate (2) are provided with side grooves (7) around the square groove-shaped flow field edge in a circle, the membrane electrode (3) is matched with the side grooves (7) in size and is arranged in the side grooves (7), the membrane electrode (3) is composed of a gas diffusion layer, a catalyst layer and a proton exchange membrane, and four corners of the anode plate (1) and the cathode plate (2) are correspondingly provided with four fixing holes (8).

2. The novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell as claimed in claim 1, wherein the height H of the cross-sectional shape of the concave quadrilateral of the flow guide column (9) satisfies: h is more than or equal to 1m and less than or equal to 3 mm; the length L of the bottom edge satisfies: l is more than or equal to 1mm and less than or equal to 3 mm; the included angle a between the side triangular wing and the bottom edge satisfies the following conditions: a is more than or equal to 30 degrees and less than or equal to 45 degrees.

3. The novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell according to claim 1, wherein the triangular wing side vertexes of the flow guiding columns (9) in adjacent rows are on the same straight line, and the longitudinal distance S2 of the gap flow channel (6) formed by the triangular wing side vertexes of the flow guiding columns (9) in adjacent rows satisfies the following conditions: s2 is more than or equal to 0.2mm and less than or equal to 1 mm; the distance S1 between the outer vertex and the inner vertex of the concave quadrilateral of the guide columns (9) adjacent to each other in the same row meets the following requirements: 3S2 is not less than S1 is not less than H.

4. The novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell according to claim 1, wherein the flow channel width of the corrugated flow channel (10) is changed alternately, and the width of the flow channel of the corrugated flow channel (10) is the smallest at the middle of the upper and lower flow guide columns (9) and gradually increases towards the two sides.

5. The novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell according to claim 1, wherein the materials of the anode plate (1), the cathode plate (2) and the flow guide columns (9) are graphite plates, metal plates or composite plates.

6. The novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell as claimed in claim 1, wherein the surface of the flow guide column (9) is coated with a hydrophobic material coating.

Technical Field

The invention belongs to the field of proton exchange membrane fuel cells, relates to a flow channel structure design of a bipolar plate of a proton exchange membrane fuel cell, and particularly relates to a gas flow channel structure beneficial to the output performance of the proton exchange membrane fuel cell.

Background

The proton exchange membrane fuel cell takes hydrogen and oxygen as fuel, directly converts chemical energy into electric energy, and is one of the most green and environment-friendly energy conversion devices. The hydrogen and the oxygen are used as reaction gases of the proton exchange membrane fuel cell, and after the hydrogen and the oxygen are introduced into the gas flow channel, the reaction gases diffuse to the center of the fuel cell and enter the gas diffusion layer, and then diffuse to the catalyst layer for electrochemical reaction. The gas flow channel of the proton exchange membrane fuel cell, the gas diffusion layer and the catalytic layer of the porous medium are necessary for the transmission of the fuel reaction gas, and influence the mass transfer process of the whole fuel cell, and finally influence the fuel utilization efficiency of the fuel cell and the overall output performance of the fuel cell.

The parallel flow channel is one of typical conventional fuel cell flow channels, and the typical parallel flow channel includes an inlet flow channel having an inlet, an outlet flow channel having an outlet, and at least one branch flow channel, wherein an inlet of each branch flow channel is communicated with the inlet flow channel, an outlet of each branch is respectively communicated with the outlet flow channel, and the reaction gas enters the flow channel through the inlet flow channel, passes through each branch flow channel, and is discharged from the outlet flow channel. Due to the structural characteristics of the parallel flow channels, the utilization rate of reaction gas is low, and water generated by the cell under high-humidity reaction gas and high current density is difficult to effectively discharge in time, so that the water is easy to gather in the cathode flow channel and block the mass transfer of the flow channel, thereby causing a flooding phenomenon and affecting the performance of the fuel cell.

The gas diffusion layer is closely connected with a polar plate of the fuel cell to form a mass transfer channel, and is an important component of the proton exchange membrane fuel cell, the gas diffusion layer is mainly used for supporting a catalyst layer, stabilizing an electrode structure and providing a gas channel, an electronic channel and a drainage channel for electrode reaction, the polar plate has the main functions of uniformly distributing reaction gas, realizing cathode and anode electronic conduction, timely heat dissipation and the like, water of the fuel cell is generated in a cathode catalyst layer and reaches a flow field through the gas diffusion layer, the structural form of the flow field is closely related to the flowing state of the water in the flow field, if the water in the flow field can not be timely discharged, a 'water flooding phenomenon' can occur, the performance of the cell is reduced, and therefore, the flow channel structure is optimized, the water generated in the fuel cell is more quickly discharged, and the output performance of the cell is improved.

Regarding the design of the gas flow channel of the proton exchange membrane fuel cell, the common design is basically the traditional parallel flow channel, serpentine flow channel or interdigital flow channel, the common point of the flow channels is basically consistent with the width of the flow channel in the branch flow channel, the flow channel of the structure usually has large pressure loss and poor flow capacity, so that the water management is promoted by improving the flow channel structure and other actions, the conveying capacity of reactants to the porous gas diffusion layer and the catalytic layer is enhanced more uniformly, the utilization efficiency of the reaction gas is enhanced, the drainage capacity of the flow channel is optimized, the flooding prevention or alleviation is achieved, and the overall output performance of the proton exchange membrane fuel cell is improved from the two aspects.

Disclosure of Invention

The present invention is directed to a novel gas flow channel structure for a bipolar plate of a pem fuel cell, which solves the above problems.

In order to achieve the purpose, the invention provides the following technical scheme: a novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell comprises a fuel cell, wherein the fuel cell is formed by stacking and assembling a plurality of monocells, each monocell comprises an anode plate, a cathode plate and a membrane electrode, the anode plate and the cathode plate are matched in size and form the bipolar plate, square-groove-shaped flow fields are arranged at the middle parts of the anode plate and the cathode plate, flow channel inlets penetrating through one corners of the square-groove-shaped flow fields are formed in the anode plate and the cathode plate, flow channel outlets penetrating through the square-groove-shaped flow fields and distributed in opposite angles with the flow channel inlets are formed in the anode plate and the cathode plate, and a gas flow channel structure is arranged in the square-groove-shaped flow fields; the gas flow channel structure is formed by arranging guide columns with concave quadrilateral cross sections in a fish scale shape in a staggered manner, a plurality of rows of guide columns are longitudinally arranged, the direction of the guide column triangular wings in the same row is the same, the direction of the guide column triangular wings in the adjacent rows is opposite, one row of guide column triangular wings close to the flow channel inlet points to the gas inflow direction, one row of guide column triangular wings close to the flow channel outlet points to the gas outflow direction, the guide columns in the square groove-shaped flow field are arranged in a staggered manner to form a plurality of groups of transverse and parallel corrugated flow channels, the guide columns in the square groove-shaped flow field are not connected with each other, a plurality of gap flow channels are formed between the adjacent corrugated flow channels, side grooves are arranged on the anode plate and the cathode plate around the edge of the square groove-shaped flow field in a circle, and the membrane electrode is matched with the side grooves in size and is arranged in the side grooves, the membrane electrode consists of a gas diffusion layer, a catalyst layer and a proton exchange membrane, and four fixing holes are correspondingly formed in four corners of the anode plate and the cathode plate.

Preferably, the height H of the concave quadrilateral cross section of the guide column satisfies: h is more than or equal to 1mm and less than or equal to 3 mm; the length L of the bottom edge satisfies: l is more than or equal to 1mm and less than or equal to 3 mm; the included angle a between the side triangular wing and the bottom edge satisfies the following conditions: a is more than or equal to 30 degrees and less than or equal to 45 degrees.

Preferably, the triangular wing side vertexes of the guide columns in adjacent rows are on the same straight line, and the longitudinal distance S2 of the gap flow channel formed by the triangular wing side vertexes of the guide columns in adjacent rows satisfies the following condition: s2 is more than or equal to 0.2mm and less than or equal to 1 mm; the distance S1 between the outer vertex and the inner vertex of the concave quadrilateral of the guide columns adjacent to each other in the same column meets the following requirements: 3S2 is not less than S1 is not less than H.

Preferably, the width of the corrugated flow channel is changed alternately, and the width of the corrugated flow channel at the middle of the upper guide column and the lower guide column is the smallest, and the width of the flow channel extending to the two sides is gradually increased.

Preferably, the anode plate, the cathode plate and the flow guide column are made of graphite plates, metal plates or composite plates.

Preferably, the surface of the flow guide column is coated with a hydrophobic material coating.

Compared with the prior art, the invention has the beneficial effects that:

1. the novel gas flow channel structure of the proton exchange membrane fuel cell bipolar plate adopts the novel gas flow channel formed by the staggered arrangement of the guide columns with the section shapes of concave quadrangles in a scale shape, ensures that the guide columns are not connected with each other, greatly increases the direct contact area of reaction gas and a reaction layer, and effectively improves the diffusion of the reaction gas to a gas diffusion layer and the discharge capacity of water generated by a cathode catalyst layer to the flow channel.

2. The triangular wings of the flow guide columns of the flow channels at the inlet of the flow channels point to the inflow direction of the reaction gas, and the reaction gas can more uniformly flow into each corrugated flow channel from the inlet of the flow channels due to the design.

3. Through the drainage effect of the flow guide columns, the flow of reaction gas in the flow channel is corrugated, the width of the flow channel of the corrugated flow channel is changed along the flow direction alternately, the flow guide columns are not connected with each other to form a gap flow channel, so that the diffusion of the reaction gas is more uniform, the corrugated flow channel with larger flow can also flow the reaction gas or water to the corrugated flow channel with smaller flow through the gap flow channel, thus the distribution of the reaction gas in the flow field is more uniform, the integral drainage capacity of the flow channel is improved, the flooding can be effectively prevented or relieved, meanwhile, the reaction gas is diffused to the catalysis layer more uniformly, the performance of the fuel cell is ensured to be more balanced, and the mass transfer efficiency of the fuel cell is improved, thereby the output efficiency and the stability of the proton exchange membrane fuel cell are improved.

4. The surface of the flow guide column is provided with a coating made of hydrophobic materials, so that the drainage capacity of the flow channel is further enhanced.

Drawings

FIG. 1 is an exploded view of the cell structure of the present invention;

FIG. 2 is a three-dimensional view of a bipolar plate of the present invention;

fig. 3 is a three-dimensional arrangement of partially adjacent flow-guiding columns in a bipolar plate according to the present invention;

FIG. 4 is a plan view of a bipolar plate of the present invention;

fig. 5 is a schematic diagram of the cross-sectional dimensions and flow channel structure dimensions of a bipolar plate flow column of the present invention.

In the figure: 1. an anode plate; 2. a cathode plate; 3. a membrane electrode; 4. a flow channel inlet; 5. a flow channel outlet; 6. a clearance flow channel; 7. a side groove; 8. a fixing hole; 9. a flow guide column; 10. a corrugated flow channel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: as shown in fig. 1 to 4, the present invention provides a technical solution: a novel gas flow channel structure for a bipolar plate of a proton exchange membrane fuel cell comprises a fuel cell, wherein the fuel cell is formed by stacking and assembling a plurality of monocells, each monocell comprises an anode plate 1, a cathode plate 2 and a membrane electrode 3, the anode plate 1 and the cathode plate 2 are matched in size and form the bipolar plate, square-groove-shaped flow fields are arranged at the middle parts of the anode plate 1 and the cathode plate 2, flow channel inlets 4 penetrating through one corners of the square-groove-shaped flow fields are formed in the anode plate 1 and the cathode plate 2, flow channel outlets 5 penetrating through the square-groove-shaped flow fields and distributed in opposite angles with the flow channel inlets 4 are formed in the anode plate 1 and the cathode plate 2, and a gas flow channel structure is arranged in the square-groove-shaped flow fields; the gas flow channel structure is formed by arranging guide columns 9 with concave quadrilateral cross sections in a fish scale shape in a staggered manner, a plurality of rows of the guide columns 9 are longitudinally arranged, the direction of the triangular wings of the guide columns 9 in the same row is the same, the direction of the triangular wings of the guide columns 9 in adjacent rows is opposite, one row of the guide columns 9 near the flow channel inlet 4 points to the gas inflow direction, one row of the guide columns 9 near the flow channel outlet 5 points to the gas outflow direction, the guide columns 9 in the square groove-shaped flow field are arranged in a staggered manner to form a plurality of groups of transverse and parallel corrugated flow channels 10, the guide columns 9 in the square groove-shaped flow field are not connected with each other, a plurality of gap flow channels 6 are formed between the adjacent corrugated flow channels 10, and the anode plate 1 and the cathode plate 2 are provided with side grooves 7 around the square groove-shaped edge in a circle, the membrane electrode 3 is matched with the side groove 7 in size and is arranged in the side groove 7, the membrane electrode 3 is composed of a gas diffusion layer, a catalyst layer and a proton exchange membrane, and four fixing holes 8 are correspondingly arranged at four corners of the anode plate 1 and the cathode plate 2.

In this embodiment, when the fuel cell starts to operate, the reactant gas enters the flow channel from the flow channel inlet 4, is guided by the triangular wings of the guide column 9 at the flow channel inlet 4, can more uniformly flow into each corrugated flow channel 10, and is guided by the corrugated flow channels 10 to converge to the flow channel outlet 5 for discharge after reaction. The gas flow channel structure is the guide post 9 that the cross-sectional shape is concave quadrangle, and the mutual discontinuity between guide post 9, and this kind of flow channel of arranging by guide post 9 and forming has greatly increased the area of contact of reactant gas and reaction layer, lets reactant gas more effectively, evenly to gas diffusion layer and catalysis layer diffusion, and water that produces at the cathode side catalysis layer also can diffuse to the flow channel more high-efficiently rapidly simultaneously, and this has further improved this fuel cell's drainage ability. The flow guide columns 9 with the concave quadrilateral cross sections are arranged in a fish scale shape in a staggered mode to form the corrugated flow channels 10 similar to the wave shape, compared with common parallel flow channels, the corrugated flow channels have high-efficiency drainage capacity, the flow channel width of the corrugated flow channels is regularly and alternately changed, the flow channel width of the flow channels at the middle of the upper flow guide column 9 and the lower flow guide column 9 is the minimum, the flow channel width extends towards the two sides, the flow channel width is gradually increased, and the corrugated alternate width flow channels can also promote the diffusion of reaction gas to the reaction layer; the plurality of gap flow channels 6 formed between the adjacent corrugated flow channels 10 can promote the reaction gas to be more uniformly diffused in the flow field, and the utilization efficiency of the reaction gas is improved.

As shown in fig. 5, the height H of the concave quadrilateral cross-sectional shape of the guide pillar 9 satisfies: h is more than or equal to 1mm and less than or equal to 3 mm; the length L of the bottom edge satisfies: l is more than or equal to 1mm and less than or equal to 3 mm; the included angle a between the side triangular wing and the bottom edge satisfies the following conditions: a is more than or equal to 30 degrees and less than or equal to 45 degrees.

In this embodiment, sufficient gas reaction contact area is thereby ensured.

As shown in fig. 5, the triangular wing side vertexes of the guide columns 9 in adjacent rows are on the same straight line, and the longitudinal distance S2 of the clearance flow channel 6 formed by the triangular wing side vertexes of the guide columns 9 in adjacent rows satisfies: s2 is more than or equal to 0.2mm and less than or equal to 1 mm; the distance S1 between the outer vertex and the inner vertex of the concave quadrilateral of the guide columns 9 adjacent to each other in the same row satisfies: 3S2 is not less than S1 is not less than H.

In this embodiment, the proper gap flow channel 6 and the distance between the outer vertex and the inner vertex of the concave quadrilateral of the flow guiding column 9 are set, which are beneficial to more uniformly diffusing the reaction gas in the flow field, improving the utilization efficiency of the reaction gas, and improving the ability of the corrugated flow channel 10 with larger flow to flow the reaction gas or water to the corrugated flow channel with smaller flow through the gap flow channel.

As shown in fig. 3 and 5, the flow channel width of the corrugated flow channel 10 is changed alternately, and the flow channel width of the corrugated flow channel 10 is the smallest at the middle of the upper and lower guide columns 9 and gradually increases toward both sides.

In this embodiment, the width of the flow channel is gradually increased from the minimum width of the flow channel at the middle of the upper and lower flow guide columns 9 to the width of the flow channel extending from both sides, and the wavy alternating width flow channel can also promote the diffusion of the reaction gas to the reaction layer.

As shown in fig. 1, the anode plate 1, the cathode plate 2 and the guide pillar 9 are made of graphite plate, metal plate or composite plate.

In this embodiment, different materials can be selected according to actual needs.

As shown in fig. 1 to 5, the surface of the diversion column 9 is coated with a hydrophobic material coating.

In this embodiment, the surface of the flow guiding column 9 is coated with a hydrophobic material coating to further enhance the drainage capability of the flow channel.

For the convenience of understanding the technical solutions of the present invention, the following detailed description will be made on the working principle or the operation mode of the present invention in the practical process.

The working principle is as follows: when the fuel cell starts to work, reaction gas enters the flow channel from the flow channel inlet 4, is guided by the triangular wings of the guide columns 9 at the flow channel inlet 4, can uniformly flow into each corrugated flow channel 10, and is guided by the corrugated flow channels 10 to converge to the flow channel outlet 5 for discharge after reaction.

The gas flow channel structure is the guide post 9 that the cross-sectional shape is concave quadrangle, and the mutual discontinuity between guide post 9, and this kind of flow channel of arranging by guide post 9 and forming has greatly increased the area of contact of reactant gas and reaction layer, lets reactant gas more effectively, evenly to gas diffusion layer and catalysis layer diffusion, and water that produces at the cathode side catalysis layer also can diffuse to the flow channel more high-efficiently rapidly simultaneously, and this has further improved this fuel cell's drainage ability.

The flow guide columns 9 with the concave quadrilateral cross sections are arranged in a fish scale shape in a staggered mode to form the corrugated flow channels 10 similar to the wave shape, compared with common parallel flow channels, the corrugated flow channels have high-efficiency drainage capacity, the flow channel width of the corrugated flow channels is regularly and alternately changed, the flow channel width of the flow channels at the middle of the upper flow guide column 9 and the lower flow guide column 9 is the minimum, the flow channel width extends towards the two sides, the flow channel width is gradually increased, and the corrugated alternate width flow channels can also promote the diffusion of reaction gas to the reaction layer; the plurality of gap flow channels 6 formed between the adjacent corrugated flow channels 10 can promote the reaction gas to be more uniformly diffused in the flow field, and the utilization efficiency of the reaction gas is improved.

The invention integrates the characteristics of the corrugated flow passage, the gap flow passage and the reducing flow passage, simultaneously increases the direct contact area of the reaction gas and the reaction layer, enhances the utilization rate of the reaction gas in the flow passage, the uniformity of gas diffusion and the drainage capacity of the flow passage, prevents or relieves flooding, improves the water management of the fuel cell, improves the output performance and the stability of the proton exchange membrane fuel cell, and further enhances the drainage capacity of the flow passage by coating the surface of the flow guide column 9 with a hydrophobic material coating.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.