Fuel cell stack

Abstract

The utility model provides a fuel cell stack. The fuel cell stack comprises a collector plate, a collector plate air inlet is formed in the collector plate, and a grating structure is arranged at the collector plate air inlet. According to the fuel cell stack provided by the utility model, the grid structure is arranged at the air inlet of the collector plate, and the air flow at the air inlet of the collector plate is buffered by utilizing the grid structure, so that the air can uniformly flow, and good inlet air can be obtained at the position of a cell close to the air inlet of the collector plate; the problem that gas flows into the collector plate gas inlet to generate a hollow area and gas flow vortex due to collision is avoided, so that the working performance of the fuel cell stack can be ensured, a false cell does not need to be arranged near the collector plate gas inlet, and the volume of the fuel cell stack can be effectively reduced on the premise of the same volume power density.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cell stacks, in particular to a fuel cell stack. Background Art

[0002] Amidst increasingly severe energy and environmental challenges, hydrogen energy, as a clean and efficient energy source, is gaining increasing attention. As one of the means of utilizing hydrogen energy, hydrogen fuel cells, a device that converts hydrogen into chemical energy, are highly sought after for their clean and environmentally friendly properties, high energy conversion efficiency, high specific power, low operating temperature, excellent durability, and environmental friendliness.

[0003] Since the output voltage of a single fuel cell is low (less than 1 volt), in actual application, the fuel cells need to be integrated into a fuel cell stack. When the fuel cell stack is filled with hydrogen and air, the direct gas entry structure of the stack causes local negative pressure inside the stack, the gas cannot be well mixed and dispersed, and the resources of several layers of bipolar plates and membrane electrode near the inlet are wasted, which in turn leads to a reduction in the utilization rate of the overall stack.

[0004] To ensure the consistency of the fuel cell stack, existing technologies often place dummy cells near the current collector to maintain the performance of cells elsewhere. However, these dummy cells cannot discharge, increasing the volume of the fuel cell stack and reducing its volumetric power density. Utility Model Content

[0005] In order to solve the technical problem in the prior art that dummy cells are provided to ensure the consistency of the fuel cell stack, resulting in increased volume and reduced power density, a fuel cell stack is provided in which a grid structure is provided at the air inlet of the collecting plate to guide the flow so as to ensure the working performance of the cells near the air inlet of the collecting plate.

[0006] A fuel cell stack comprises a collecting plate, wherein the collecting plate is provided with a collecting plate air inlet, and a grid structure is provided at the collecting plate air inlet.

[0007] The fuel cell stack also includes an end plate, which is arranged on one side of the collecting plate and is provided with an end plate air inlet. The end plate air inlet is connected to the collecting plate air inlet, and the projection of the end plate air inlet on the collecting plate is located on the grid structure.

[0008] The central axis of the end plate air inlet is collinear with the central axis of the grille structure.

[0009] The grid structure shields at least a portion of the collector plate air inlet, and air holes are provided on the grid structure.

[0010] The flow area of ​​the air holes gradually increases in a direction away from the end plate.

[0011] The flow area of ​​the air holes gradually increases from the center of the grid structure to the edge of the grid structure.

[0012] The air inlet of the collecting plate is in the shape of an elongated strip, the grille structure is located in the middle of the elongated strip, and in the length direction of the elongated strip, the flow area of ​​the air holes gradually increases from the middle of the elongated strip to the edge of the elongated strip.

[0013] The fuel cell stack further includes an insulating plate, which is disposed between the current collecting plate and the end plate. The insulating plate is provided with an insulating plate flow hole, and the end plate air inlet is connected to the current collecting plate air inlet through the insulating plate flow hole.

[0014] The air inlet of the collecting plate is located within the projected area of ​​the flow hole of the insulating plate on the collecting plate

[0015] The end plate, the insulating plate and the current collecting plate are integrally formed; and / or a sealing structure is provided between the end plate and the insulating plate; and / or a sealing structure is provided between the insulating plate and the current collecting plate.

[0016] The fuel cell stack provided by the present invention is provided with a grille structure at the air inlet of the collecting plate, and the grille structure is used to buffer the airflow at the air inlet of the collecting plate, so that the gas can flow evenly, and the batteries near the air inlet of the collecting plate can also obtain good air intake, avoiding the problem of hollow areas and airflow vortices caused by collision after the gas flows into the air inlet of the collecting plate, thereby ensuring the working performance of the fuel cell stack, and there is no need to set up dummy batteries near the air inlet of the collecting plate. Under the premise of the same volume power density, the volume of the fuel cell stack can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a fuel cell stack provided in an embodiment of the present invention;

[0018] Figure 2 A schematic structural diagram of a current collecting plate and a grid structure of a fuel cell stack provided by an embodiment of the present utility model;

[0019] Figure 3 A three-dimensional diagram of the current collecting plate and grid structure of a fuel cell stack provided by an embodiment of the present utility model;

[0020] Figure 4 A cross-sectional view of a gas hole of a fuel cell stack provided by an embodiment of the present utility model;

[0021] Figure 5A bottom view of the end plate, insulating plate and current collecting plate of the fuel cell stack provided by an embodiment of the present utility model;

[0022] Figure 6 A side view of the end plate, insulating plate and current collecting plate of a fuel cell stack provided by an embodiment of the present utility model;

[0023] Figure 7 A top view of the end plate, insulating plate and current collecting plate of a fuel cell stack provided in an embodiment of the present utility model;

[0024] Figure 8 A schematic structural diagram of an insulating plate of a fuel cell stack provided in an embodiment of the present invention;

[0025] In the picture:

[0026] 1. Collector plate; 11. Collector plate air inlet; 2. Grille structure; 3. End plate; 31. End plate air inlet; 21. Air hole; 4. Insulation plate; 41. Insulation plate flow hole. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate for the embodiments of the present invention described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatuses.

[0030] It should be noted that in the description of this utility model, terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These terms are used solely for ease of description and are not intended to indicate or imply that the device or component described must have a specific orientation, be constructed, or operate in a specific position. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Furthermore, it should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "installed," "set," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0032] A fuel cell stack primarily consists of upper and lower end plates, upper and lower insulating plates, cathode and anode current collectors, sealing gaskets, membrane electrodes, bipolar plates, and bolts and nuts. The current collector, which collects and outputs charge within the fuel cell stack, is typically made of copper with a modified surface treatment to improve conductivity and corrosion resistance. The inlet and outlet ports on a conventional current collector are the same size and shape as those on the bipolar plates and insulating plates. In practice, when hydrogen and air are charged into a fuel cell stack, the fuel enters the fuel cell at an extremely high rate due to the direct flow of fuel into the fuel cell. This can lead to insufficient gas supply to individual cells near the current collector. Furthermore, this direct gas flow structure creates localized negative pressure within the stack, preventing proper mixing and dispersion of the gases. This wastes resources from the bipolar plates and membrane electrodes near the inlet, resulting in reduced overall stack utilization. To ensure consistent fuel cell stack performance, existing techniques often place dummy cells near the current collector to ensure the performance of cells elsewhere. However, the dummy battery cannot discharge, so the installation of the dummy battery will increase the volume of the fuel cell stack and reduce the volume power density of the fuel cell stack. Figures 1 to 8The fuel cell stack shown includes a collector plate 1, which is provided with a collector plate air inlet 11. A grid structure 2 is provided at the collector plate air inlet 11. The grid structure 2 is used to buffer the airflow at the collector plate air inlet 11, allowing the gas to flow evenly. The cells near the collector plate air inlet 11 can also obtain good air intake, avoiding the problems of hollow areas and airflow vortices caused by collisions after the gas flows into the collector plate air inlet 11. Therefore, the operating performance of the fuel cell stack can be guaranteed, and there is no need to set up dummy cells near the collector plate air inlet 11. Under the premise of maintaining the same volume power density, the volume of the fuel cell stack can be effectively reduced.

[0033] Specifically, the fuel cell stack further includes an end plate 3, which is disposed on one side of the current collecting plate 1 and is provided with an end plate air inlet 31. The end plate air inlet 31 is in communication with the current collecting plate air inlet 11, and the projection of the end plate air inlet 31 on the current collecting plate 1 is located on the grid structure 2. The end plate 3 and current collecting plate 1 are stacked, and an external air supply structure delivers gas to the current collecting plate air inlet 11 through the end plate air inlet 31. At this time, the gas flows in a direction perpendicular to the current collecting plate 1. Therefore, by aligning the end plate air inlet 31 with the grid structure 2, the gas can collide with the grid structure 2 and be buffered by the grid structure 2, ensuring that the gas can quickly mix and diffuse in all directions, avoiding the problems of hollow areas and airflow vortices, thereby ensuring the operating performance of the fuel cell stack.

[0034] Preferably, the central axis of the end plate air inlet 31 is collinear with the central axis of the grid structure 2, ensuring that the gas entering the end plate air inlet 31 can be buffered by the grid structure 2, further ensuring the working performance of the fuel cell stack.

[0035] The grille structure 2 shields at least a portion of the collector plate air inlet 11, and the grille structure 2 buffers the airflow that directly collides with the grille structure 2, while the remaining portion of the collector plate air inlet 11 allows gas to flow smoothly, thereby avoiding excessive buffering effect of the grille structure 2 on the airflow and affecting the air intake efficiency of the fuel cell stack, and the grille structure 2 is provided with an air hole 21, and part of the airflow that directly collides with the grille structure 2 can flow through the air hole 21 and reach the other side of the grille structure 2. At this time, a working battery can be set near the collector plate air inlet 11, and the gas passing through the air hole 21 can diffuse to the battery near the collector plate air inlet 11, thereby ensuring the working performance of this part of the battery, thereby improving the working performance of the fuel cell stack.

[0036] In the direction away from the end plate 3, the flow area of ​​the air hole 21 gradually increases. When the gas flows through the air hole 21, the flow rate will be reduced due to the increase in the flow area, thereby achieving a buffering effect on the gas. At the same time, the increase in the flow area can make the gas diffuse and transfer in a trumpet shape, thereby increasing the gas flow of the battery near the collector plate air inlet 11 and ensuring the working performance of this part of the battery.

[0037] Since the central axis of the end plate air inlet 31 is collinear with the central axis of the grille structure 2, the gas flow rate at the center of the grille structure 2 is the largest. Along the center of the grille structure 2 to the edge of the grille structure 2, the flow area of ​​the air holes 21 gradually increases, so that most of the gas can be buffered and diverted by the grille structure 2, ensuring the working performance of other batteries in the fuel cell stack, and the middle air holes 21 can allow part of the gas to pass through and reach the batteries near the collector plate air inlet 11, ensuring the working performance of the batteries near the collector plate air inlet 11, and ultimately ensuring the working performance of the fuel cell stack.

[0038] like Figure 2 and 3 As shown, the shape of the collector plate air inlet 11 is a long strip, and the length direction of the long strip is the width direction of the fuel cell stack, so as to ensure that the air flow in the fuel cell stack is evenly distributed. The grid structure 2 is located in the middle of the long strip. At this time, the middle part of the collector plate air inlet 11 will be shielded by the grid structure 2, while the two end parts of the collector plate air inlet 11 are not shielded by the grid structure 2 and are used for a large amount of gas to pass through. After the gas is filled into the grid structure 2, it will flow along the surface of the grid structure 2. Most of the gas will flow along the length direction of the grid structure 2, and a small part of the gas will flow through the grid structure 2. The gas flows through the air holes 21 on the grid structure 2. During the process of the gas flowing along the length direction of the grid structure 2, the velocity component of the gas in the direction of passing through the grid structure 2 gradually decreases. Therefore, in the length direction of the long strip, from the middle of the long strip to the edge of the long strip, the flow area of ​​the air holes 21 gradually increases, which can ensure that the gas flow on the lower side of the grid structure 2 is basically the same, and ensure that part of the gas passes through and reaches the battery near the collector plate air inlet 11, thereby ensuring the working performance of the battery near the collector plate air inlet 11, and finally ensuring the working performance of the fuel cell stack.

[0039] The fuel cell stack also includes an insulating plate 4, which is disposed between the current collecting plate 1 and the end plate 3. The insulating plate 4 is provided with insulating plate flow holes 41, through which the end plate air inlet 31 communicates with the current collecting plate air inlet 11. The insulating plate 4 insulates the end plate 3 from the current collecting plate 1, ensuring the operational reliability of the fuel cell stack. To ensure reliable gas flow, gas from the end plate air inlet 31 can flow through the insulating plate flow holes 41 to the current collecting plate air inlet 11.

[0040] The collecting plate air inlet 11 is within the projected area of ​​the insulating plate flow hole 41 on the collecting plate 1, that is, the flow area of ​​the insulating plate flow hole 41 needs to be larger than the flow area of ​​the collecting plate air inlet 11 to avoid the insulating plate flow hole 41 blocking the gas and ensure reliable air intake of the fuel cell stack.

[0041] The end plates 3, the insulating plates 4, and the current collecting plates 1 are integrally formed, improving the sealing performance between the end plates 3, the insulating plates 4, and the current collecting plates 1, reducing the risk of gas leakage, and improving the safety and reliability of the fuel cell stack. Preferably, the end plates 3, the insulating plates 4, and the current collecting plates 1 are sealed using a sealant injection process (or a sealant encapsulation process), which significantly improves sealing performance and assembly efficiency compared to the traditional layer-by-layer stacking method.

[0042] A sealing structure is provided between the end plate 3 and the insulating plate 4 to improve the sealing performance between the end plate 3 and the insulating plate 4, reduce the risk of gas leakage, and improve the safety and reliability of the fuel cell stack.

[0043] A sealing structure is provided between the insulating plate 4 and the current collecting plate 1 to improve the sealing performance between the insulating plate 4 and the current collecting plate 1, reduce the risk of gas leakage, and improve the safety and reliability of the fuel cell stack.

[0044] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A fuel cell stack, characterized in that: It comprises a current collecting plate (1), the current collecting plate (1) being provided with a current collecting plate air inlet (11), and a grid structure (2) being provided at the current collecting plate air inlet (11).

2. The fuel cell stack according to claim 1, wherein: The fuel cell stack further comprises an end plate (3), the end plate (3) being arranged on one side of the current collecting plate (1), and an end plate air inlet (31) being provided on the end plate (3), the end plate air inlet (31) being in communication with the current collecting plate air inlet (11), and a projection of the end plate air inlet (31) on the current collecting plate (1) being located on the grid structure (2).

3. The fuel cell stack according to claim 2, characterized in that: The central axis of the end plate air inlet (31) is collinear with the central axis of the grid structure (2).

4. The fuel cell stack according to claim 2, wherein: The grid structure (2) shields at least a portion of the collector plate air inlet (11), and air holes (21) are provided on the grid structure (2).

5. The fuel cell stack according to claim 4, characterized in that: In a direction away from the end plate (3), the flow area of ​​the air hole (21) gradually increases.

6. The fuel cell stack according to claim 4, characterized in that: Along the direction from the center of the grid structure (2) to the edge of the grid structure (2), the flow area of ​​the air holes (21) gradually increases.

7. The fuel cell stack according to claim 4, characterized in that: The collector plate air inlet (11) is in the shape of an elongated strip, the grid structure (2) is located in the middle of the elongated strip, and in the length direction of the elongated strip, the flow area of ​​the air hole (21) gradually increases from the middle of the elongated strip to the edge of the elongated strip.

8. The fuel cell stack according to claim 2, characterized in that: The fuel cell stack further comprises an insulating plate (4), the insulating plate (4) being arranged between the current collecting plate (1) and the end plate (3), the insulating plate (4) being provided with an insulating plate flow hole (41), and the end plate air inlet (31) being connected to the current collecting plate air inlet (11) via the insulating plate flow hole (41).

9. The fuel cell stack according to claim 8, characterized in that: The collector plate air inlet (11) is located within the projected area of ​​the insulating plate flow hole (41) on the collector plate (1).

10. The fuel cell stack according to claim 8, characterized in that: The end plate (3), the insulating plate (4) and the current collecting plate (1) are integrally formed; and / or a sealing structure is provided between the end plate (3) and the insulating plate (4); and / or a sealing structure is provided between the insulating plate (4) and the current collecting plate (1).

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