Air-cooled fuel cell metal bipolar plate

Abstract

The invention provides a metal bipolar plate of an air-cooled fuel cell, belongs to the technical field of battery polar plates, and aims to solve the problem that the battery performance is reduced and even the service life is attenuated due to serious excessive reaction air supply under the condition of high power of the air-cooled fuel cell, the metal bipolar plate comprises a polar plate body, and a plurality of ridges are distributed on the positive electrode surface of the polar plate body in an array manner; a cooling channel and a reaction channel are formed inside and outside the ridge, a ventage is formed in the side wall of the ridge, and the front end of the ventage is connected with a guide vane arranged in the reaction channel.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery plates, and more specifically, particularly relates to a metal bipolar plate for an air-cooled fuel cell. Background Art

[0002] Proton exchange membrane hydrogen fuel cell (PEMFC) is a power generation device that converts the chemical energy of hydrogen and oxygen into electrical energy. It has the advantages of being clean, efficient, and low noise, and can be widely used in electric vehicles, drones, portable power sources, etc. According to the heat dissipation method, proton exchange membrane hydrogen fuel cells (hereinafter referred to as hydrogen fuel cells) can be mainly divided into two types: liquid-cooled and air-cooled. Among them, air-cooled hydrogen fuel cells use ambient air as a cooling medium, and use a fan to drive the air to flow through the cooling channel. For air-cooled hydrogen fuel cells, ambient air is not only a cooling medium, but also a source of reactant oxygen. Therefore, in order to simplify the battery structure, the cooling air and reaction air supply channels of air-cooled hydrogen fuel cells are usually overlapped or parallel. The ambient air flows through the cathode channel driven by the fan, on the one hand, providing the battery with the oxygen required for the reaction, and on the other hand, taking away the heat generated by the battery reaction.

[0003] In metal bipolar plates, the cavity structure makes the cooling air and reaction air channels initially separated and parallel to each other, but due to the shared fan, the cooling air and reaction air flow rates are equivalent. Under high power conditions, the demand for cooling air is more than ten times or even dozens of times that of reaction air. To ensure the heat dissipation effect of the battery, the fan is mainly adjusted according to the demand for cooling air, which results in a serious oversupply of reaction air. Excessive reaction air flow will cause water loss in the membrane electrode and imbalance in water management, ultimately leading to a decline in battery performance and even a reduction in operating life.

[0004] Therefore, in view of this, the existing structure and deficiencies are studied and improved, and an air-cooled fuel cell metal bipolar plate is provided, in order to achieve a more practical purpose. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a metal bipolar plate for an air-cooled fuel cell to solve the problem that under high power conditions, the reaction air supply of the air-cooled fuel cell is seriously excessive, resulting in a decrease in battery performance and even a reduction in operating life.

[0006] The purpose and effect of the air-cooled fuel cell metal bipolar plate of the present invention are achieved by the following specific technical means:

[0007] A metal bipolar plate for an air-cooled fuel cell comprises a plate body, wherein a plurality of ridges are distributed in an array on the positive electrode surface of the plate body, cooling channels and reaction channels are formed inside and outside the ridges, a leakage opening is opened on the side wall of the ridges, and a guide piece placed in the reaction channel is connected to the front end of the leakage opening.

[0008] Furthermore, leakage openings are provided on both side walls of the ridge beam, and guide plates are provided at the leakage points.

[0009] Furthermore, the angle between the guide piece and the leakage opening is an acute angle.

[0010] Furthermore, the leak is located in the middle of the spine.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. A "window sash" is formed by the cooperation of the leak and the guide vane. Due to the obstruction of the "window sash", the flow of the reaction air is blocked. Under the condition of sharing the fan, the flow rate of the inlet reaction air is significantly smaller than the flow rate of the cooling air, thereby realizing the flow distribution of the cooling air and the reaction air at the channel inlet. Under the condition of ensuring the large flow rate of cooling air for heat dissipation, the reaction air still maintains the small flow required for the appropriate reaction, avoiding excessive water in the membrane electrode being blown away by the reaction air.

[0013] 2. The existence of the "window" allows a portion of the cooling air to be separated in the middle of the process as reaction air, avoiding insufficient oxygen in the reaction air in the second half of the process, and improving the uniformity of oxygen concentration distribution and the overall performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a metal bipolar plate of an air-cooled fuel cell of the present invention.

[0015] Figure 2 It is a schematic diagram of the planar structure of the present invention.

[0016] Figure 3 It is a structural schematic diagram of embodiment 2 of the present invention.

[0017] Figure 4 It is a schematic diagram of the planar structure of the third embodiment of the present invention.

[0018] In the figure, the corresponding relationship between the component names and the figure numbers is as follows:

[0019] 1. Plate body; 2. Spine; 3. Leakage; 4. Guide. DETAILED DESCRIPTION

[0020] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0021] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Embodiment 1:

[0024] As attached Figure 1 To Attachment Figure 2 As shown:

[0025] The present invention provides an air-cooled fuel cell metal bipolar plate, comprising a plate body 1, a plurality of ridges 2 are distributed in an array on the positive electrode surface of the plate body 1, cooling channels and reaction channels are formed inside and outside the ridges 2, a gas diffusion layer in contact with the positive electrode surface of the plate body 1 is used to permeate air, and the air flowing through the inside of the ridges 2 takes away heat to play a heat dissipation role, and the air flowing through the outside of the ridges 2 passes through the gas diffusion layer and undergoes a series of reactions with the negative electrode hydrogen surface of the adjacent metal bipolar plate through the proton exchange membrane. This is the principle of a hydrogen fuel cell and will not be described in detail.

[0026] Under high power conditions, excessive reaction air flow will cause water loss in the membrane electrode and unbalanced water management. In the present embodiment, a leak 3 is provided on the side wall of the ridge beam 2, and a guide vane 4 is obliquely connected to the front end of the leak 3. The guide vane 4 and the leak 3 form a "window". The guide vane 4 can block the air flow in front of the reaction channel. At the same time, after the reaction air is consumed in front of the guide vane 4, the setting of the leak 3 enables the air in the cooling channel behind the guide vane 4 to be replenished into the reaction channel, thereby increasing the oxygen concentration and avoiding the problem of insufficient oxygen in the second half. This improves the uniformity of oxygen concentration distribution and the overall performance of the battery. While ensuring the large flow rate of cooling air to dissipate heat, the reaction air still maintains the small flow required for an appropriate reaction, thereby preventing the moisture in the membrane electrode (composed of a gas diffusion layer and a proton exchange membrane) from being excessively swept away by the reaction air.

[0027] The leak 3 is located in the middle of the spine 2 to prevent the "window" from being too close to the front, which results in insufficient air consumption in front of the "window" in the reaction channel, and makes the oxygen concentration of the "window" too early to be replenished.

[0028] At the same time, avoid the "window" being too far back, which causes delayed gas replenishment and unsatisfactory air concentration in the first half of the reaction.

[0029] Embodiment 2:

[0030] like Figure 3 As shown, the difference between this embodiment and the first embodiment is that the leak 3 extends through the surface of the ridge beam 2, thereby expanding the longitudinal space where the air in the cooling channel just enters the reaction channel and reducing the gas pressure at the leak 3 where the air is replenished.

[0031] Embodiment three:

[0032] like Figure 4 As shown, the difference between this embodiment and the first embodiment is that leakage openings 3 are provided on both side walls of the backbone 2, and guide pieces 4 are provided at the leakage points 3. The provision of the guide pieces 4 on both sides of the backbone 2 forms a constriction in the reaction channel, which has a better air blocking effect. At the same time, adsorption force is formed at the leakage point for air replenishment, and air replenishment is more rapid, making the oxygen concentration uniform section longer. The angle between the guide piece 4 and the leakage opening 3 is an acute angle, which blocks the air flow rate in the reaction channel while guiding the air to shrink toward the center and then diffuse, so that the oxygen in the second half of the reaction channel is more uniform.

[0033] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A metal bipolar plate for an air-cooled fuel cell, comprising a plate body (1), wherein a plurality of ridges (2) are distributed in an array on the positive electrode surface of the plate body (1), and cooling channels and reaction channels are formed inside and outside the ridges (2), characterized in that: A leakage opening (3) is provided on the side wall of the ridge beam (2), and a guide piece (4) placed in the reaction channel is connected to the front end of the leakage opening (3).

2. The air-cooled fuel cell metal bipolar plate according to claim 1, characterized in that: Leakage openings (3) are provided on both side walls of the ridge beam (2), and guide plates (4) are provided at the leakage openings (3).

3. The air-cooled fuel cell metal bipolar plate according to claim 1, characterized in that: The angle between the guide piece (4) and the leakage opening (3) is an acute angle.

4. The air-cooled fuel cell metal bipolar plate according to claim 1, characterized in that: The leak (3) is located in the middle of the spine (2).

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