Fuel cell bipolar plate with backflow prevention function

Abstract

The application provides a fuel cell bipolar plate with backflow prevention function, and belongs to the technical field of proton exchange membrane fuel cells, and solves the problem that liquid water backflow in common pipes cannot be avoided in the prior art, causing the fuel cell to fail to work normally. The bipolar plate is composed of an anode single plate and a cathode single plate, and is sequentially provided with an input pipe opening for gas inflow, an inlet bridge area, a flow field flow channel area, an outlet bridge area, and an output pipe opening for gas outflow. The flow field flow channel area is located in the activation area of the fuel cell single cell. The outlet bridge area is provided with a backflow prevention structure for preventing liquid water in the common pipe outside the fuel cell from entering the inside of the fuel cell. The input gas of the fuel cell enters the flow field flow channel area from the input pipe opening through the inlet bridge area, water is generated through electrochemical reaction in the inside of the fuel cell, and the remaining gas after the reaction and the generated water flow out of the fuel cell through the outlet bridge area and the output pipe opening in sequence and flow to the common pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of proton exchange membrane fuel cell, and particularly relates to a fuel cell bipolar plate with anti-backflow function. BACKGROUND

[0002] The proton exchange membrane fuel cell has the characteristics of green, no pollution and high conversion efficiency, can convert chemical energy in hydrogen into electric energy through electrochemical reaction, and does not generate pollution gas in the whole process, and is widely concerned as a clean new energy.

[0003] The working temperature of the proton exchange membrane fuel cell is usually lower than 100 DEG C, and liquid water is generated in the fuel cell during actual operation. The water generated by each single cell is collected in a common pipe, and needs to be discharged in time. However, when the proton exchange membrane fuel cell is applied to the field of automobile, dynamic processes such as turning inevitably exist, and the liquid water in the common pipe is easy to enter the single cell again, causing local gas shortage in the single cell, and further causing the single cell to stop working due to too low voltage. SUMMARY

[0004] In view of the above analysis, the embodiment of the present application aims to provide a fuel cell bipolar plate with anti-backflow function, to solve the problem that the liquid water in the common pipe cannot be prevented from backflowing, causing the fuel cell to work abnormally.

[0005] In one aspect, the embodiment of the present application provides a fuel cell bipolar plate with anti-backflow function, which is composed of an anode single plate and a cathode single plate, and is sequentially provided with an input pipe opening for gas inflow, an inlet bridge area, a flow field flow channel area, an outlet bridge area, and an output pipe opening for gas outflow.

[0006] The flow field flow channel area is located in the activation area of the single cell of the fuel cell.

[0007] The outlet bridge area is provided with an anti-backflow structure for preventing the liquid water in the common pipe outside the fuel cell from entering the inside of the fuel cell.

[0008] The input gas of the fuel cell enters the flow field flow channel area from the input pipe opening through the inlet bridge area, and the electrochemical reaction occurs in the inside of the fuel cell to generate water. The remaining gas after the reaction and the generated water flow out of the fuel cell in sequence through the outlet bridge area and the output pipe opening, and flow to the common pipe.

[0009] The beneficial effects of the above technical solutions are as follows: a fuel cell bipolar plate with anti-backflow function is provided, electrochemical reaction occurs in the activation zone inside the fuel cell, and finally reaches the public pipeline through the outlet bridge area, so as to effectively prevent liquid water from entering the fuel cell. In particular, the anti-backflow structure is added in the bridge area, which can effectively prevent liquid water from entering the stack during the instantaneous dynamic process of the vehicle.

[0010] Based on the further improvement of the above bipolar plate, the anti-backflow structure further comprises a one-way valve structure arranged in the outlet bridge area; and,

[0011] The opening direction of the one-way valve structure is the channel from the fuel cell interior to the public pipeline, and the closing direction is the channel from the fuel cell interior to the public pipeline.

[0012] Further, the number of one-way valve structures is more than one; and,

[0013] All one-way valve structures are equidistantly distributed in the area where the outlet bridge area is located, and the distance is set so that the channel from the fuel cell interior to the public pipeline is completely closed when all one-way valve structures are closed.

[0014] Further, the number of one-way valve structures is more than one; and,

[0015] All one-way valve structures are only distributed on the lower side of the area where the outlet bridge area is located, and there is no one-way valve structure on the higher side of the area where the outlet bridge area is located, so that the liquid water in the public pipeline is difficult to flow back to the fuel cell interior.

[0016] Further, each one-way valve structure is a dome structure arranged along the fluid direction, which is composed of more than three equally divided valve petals, and when there is no fluid passing through, the valve petals are at an angle of 5°-60° with the water flow direction, the distance between adjacent valve petals is 1-5 mm, and the height h of the valve petals is 0.1-1.5 mm.

[0017] Further, the edge area of the anode single plate is provided with an anode single plate sealing groove, and the edge area of the cathode single plate is provided with a cathode single plate sealing groove; and,

[0018] The anode single plate sealing groove is further provided with an anode single plate sealing strip, and the cathode single plate sealing groove is further provided with a cathode single plate sealing strip.

[0019] At least two positioning holes are further arranged on the anode single plate and the cathode single plate.

[0020] Further, the bipolar plate is sequentially provided with an input pipe opening for gas inflow, an inlet bridge area, an inlet distribution area, a flow field flow channel area, an outlet distribution area, an outlet bridge area, and an output pipe opening for gas outflow; and,

[0021] The import distribution area and the export distribution area are provided with dot matrix protruding structures to make the gas flow uniform.

[0022] Further, the flow field flow channel area comprises an anode flow field flow channel area on the anode single plate and a cathode flow field flow channel area on the cathode single plate; wherein,

[0023] The anode flow field flow channel area and the cathode flow field flow channel area are both wave-shaped reaction areas; the wave shapes of the anode flow field flow channel area and the cathode flow field flow channel area are the same in period and amplitude, and the wave crests and wave troughs of the two areas are staggered.

[0024] Further, when the number of positioning holes is two, the two positioning holes are diagonally distributed.

[0025] Further, the anode single plate is provided with a bonding line groove area on the side facing the cathode single plate, which is used for bonding the anode single plate and the cathode single plate and sealing the cooling liquid flow field flow channel area; and,

[0026] The anode single plate is provided with a sealing line groove area on the side away from the cathode single plate, and the cathode single plate is provided with a sealing line groove area on the side away from the anode single plate, which are used for sealing the fuel gas flow field flow channel area and the air flow field flow channel area.

[0027] Compared with the prior art, the present application can achieve at least one of the following beneficial effects:

[0028] 1. The water generated by electrochemical reaction flows to the outlet bridge area through the outlet distribution area and is finally discharged from the fuel cell to the public pipeline, and the anti-backflow structure in the bridge area can effectively prevent liquid water from entering the fuel cell during the transient dynamic process of the vehicle.

[0029] 2. Inspired by the venous valve structure, a membrane valve type anti-backflow structure is designed to prevent liquid water from entering the fuel cell.

[0030] 3. The structure is simple, effective and practical.

[0031] The summary is provided to introduce a selection of concepts in a simplified form, which will be further described below in the detailed description. The summary is not intended to identify key or essential features of the application, nor is it intended to limit the scope of the application. BRIEF DESCRIPTION OF DRAWINGS

[0032] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and in which:

[0033] Figure 1A schematic diagram of the planar structure of the bipolar plate of Example 1 is shown;

[0034] Figure 2 A schematic diagram of the one-way valve structure of Example 2 is shown;

[0035] Figure 3 A schematic diagram of the outlet bridge area structure of Example 2 for preventing gas and liquid backflow is shown;

[0036] Figure 4 A schematic diagram of the outlet bridge area structure of Example 2 for preventing only liquid backflow is shown;

[0037] Figure 5 A schematic diagram of the size of the one-way valve structure of Example 2 is shown.

[0038] Reference numerals

[0039] 1 - input port; 2 - inlet bridge area; 3 - flow field channel area; 4 - outlet bridge area; 5 - output port. DETAILED DESCRIPTION

[0040] Embodiments of the present application will be described below in greater detail with reference to the accompanying drawings. While embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0041] The term "comprising" and variations thereof as used herein are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an overly literal sense unless expressly so defined herein. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0042] Example 1

[0043] One embodiment of the present application discloses a fuel cell bipolar plate with backflow prevention function, as shown by the combination of an anode single plate and a cathode single plate, the bipolar plate is sequentially provided with an input port 1 for gas inflow, an inlet bridge area 2, a flow field channel area 3, an outlet bridge area 4, and an output port 5 for gas outflow. Figure 1

[0044] The flow field channel area 3 is located in the activation area of the fuel cell single cell.

[0045] ​The outlet bridge area 4 is provided with an anti-backflow structure for preventing liquid water in the public pipeline outside the fuel cell from entering the inside of the fuel cell. In addition to the one-way membrane flap structure in Embodiment 2, the anti-backflow structure can also adopt the structure of Chinese Patents CN201920031308.0 and CN202210670359.4, etc.

[0046] The input gas of the fuel cell enters the flow field channel area 3 from the input port 1 through the inlet bridge area 2, and the water generated by the electrochemical reaction inside the fuel cell, and the remaining gas and the generated water flow out of the fuel cell in turn through the outlet bridge area 4 and the output port 5, and flow to the public pipeline.

[0047] The input port 1 and the output port 5 jointly constitute the total port of this embodiment, which is used for gas and liquid to flow in and out.

[0048] In implementation, according to a large number of tests, compared with the scheme of setting the anti-backflow structure in the total port, in the latter (setting the anti-backflow structure in the total port), liquid water is easy to accumulate between the total port plates during use, increasing the flow resistance and easily corroding the plates. After implementing the above scheme of this embodiment, the shortcomings of the latter are overcome, which can not only prevent liquid water in the public pipeline from entering the inside of the fuel cell, but also does not affect the discharge of liquid water.

[0049] Compared with the prior art, this embodiment provides a fuel cell bipolar plate with an anti-backflow function. The electrochemical reaction occurs in the activation area inside the fuel cell, and finally reaches the public pipeline to discharge the fuel cell through the outlet bridge area 4, so as to effectively prevent liquid water from entering the inside of the fuel cell. In particular, by adding the anti-backflow structure in the bridge area, liquid water entering the inside of the stack during the instantaneous dynamic process of the vehicle can be effectively avoided.

[0050] Embodiment 2

[0051] On the basis of Embodiment 1, the anti-backflow structure further includes a one-way valve structure provided in the outlet bridge area 4, as shown in Figure 2 The opening direction of the one-way valve structure is to open the channel from the inside of the fuel cell to the public pipeline, and the closing direction is to close the channel from the inside of the fuel cell to the public pipeline.

[0052] In order to prevent liquid water in the outlet manifold from entering the fuel cell during the dynamic process such as turning of the vehicle, it has been proved by tests that the one-way valve structure as shown in Figure 2 The gas or liquid confluence will generate greater resistance and be difficult to enter the inside of the fuel cell.

[0053] Preferably, the number of one-way valve structures is multiple. And all one-way valve structures are equidistantly distributed in the area where the outlet bridge area 4 is located, and the distance is set so that when all one-way valve structures are closed, the passage from the inside of the fuel cell to the common pipe is completely closed (both gas passage and liquid passage are closed), as shown in Figure 3 , to achieve the function of preventing gas and liquid backflow.

[0054] Preferably, the number of one-way valve structures is more than one. And all one-way valve structures are only distributed on the lower side of the area where the outlet bridge area 4 is located, while the higher side of the area where the outlet bridge area 4 is located has no one-way valve structure, as shown in Figure 4 , so that the liquid water in the common pipe is difficult to flow back to the inside of the fuel cell, to achieve the function of preventing liquid backflow.

[0055] Each one-way valve structure is a dome structure arranged along the fluid direction, which is composed of more than three evenly divided valve petals, as shown in Figure 5 , in the natural state (when there is no fluid passing through), the angle θ between the valve petals and the water flow direction is 5°-60°, the distance l1 between adjacent valve petals is 1-5mm, the parameter l2 is 0.5-2mm (which can be derived according to h and θ), and the height h of the valve petals is 0.1-1.5mm.

[0056] Preferably, the edge area of the anode single plate is provided with an anode single plate sealing groove, and the edge area of the cathode single plate is provided with a cathode single plate sealing groove. And the anode single plate sealing groove is further provided with an anode single plate sealing strip. The cathode single plate sealing groove is further provided with a cathode single plate sealing strip to achieve better sealing effect.

[0057] Preferably, at least two positioning holes are further provided on the anode single plate and the cathode single plate. When the number of positioning holes is two, the two positioning holes are diagonally distributed, which is convenient for accurate installation.

[0058] Preferably, the bipolar plate is sequentially provided with an input port 1 for gas inflow, an inlet bridge area 2, an inlet distribution area, a flow field flow channel area 3, an outlet distribution area, an outlet bridge area 4, and an output port 5 for gas outflow. And the inlet distribution area and the outlet distribution area are both provided with a dot matrix type of convex structure to make the gas flow uniform.

[0059] Preferably, the flow field flow channel area 3 includes an anode flow field flow channel area on the anode single plate and a cathode flow field flow channel area on the cathode single plate.

[0060] The anode flow field flow channel area and the cathode flow field flow channel area are both wave-shaped reaction areas. The anode flow field flow channel area and the cathode flow field flow channel area have the same wave shape period and amplitude, and the wave crests and troughs of the two areas are staggered. This structure can achieve more sufficient electrochemical reaction.

[0061] Preferably, the side of the anode single plate facing the cathode single plate is provided with a bonding line groove area for bonding the anode single plate, the cathode single plate and sealing the cooling liquid flow field flow channel area. And, the side of the anode single plate away from the cathode single plate, the side of the cathode single plate away from the anode single plate are both provided with a sealing line groove area for sealing the fuel gas flow field flow channel area, the air flow field flow channel area. Reasonable arrangement is conducive to obtaining good sealing effect and saving arrangement space.

[0062] Compared with the prior art, the mobile test bin provided by the embodiment has the following advantages

[0063] Beneficial effects:

[0064] 1. The water generated by the electrochemical reaction is converged to the outlet bridge area through the outlet distribution area, and finally discharged from the fuel cell to the public pipeline. The anti-backflow structure is added in the bridge area, which can effectively avoid the liquid water entering the internal stack during the transient dynamic process of the vehicle.

[0065] 2. Inspired by the venous valve structure, a membrane valve type anti-backflow structure is designed, which can avoid the liquid water entering the fuel cell.

[0066] 3. The structure is simple, effective and practical.

[0067] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical application or improvement of the prior art of the embodiments, or to enable other ordinary skilled in the art to understand the embodiments disclosed herein.

Claims

1. A fuel cell bipolar plate with anti-backflow function, comprising an anode plate and a cathode plate, characterized in that, The bipolar plate is sequentially provided with an inlet port for gas inflow, an inlet bridge area, a flow field channel area, an outlet bridge area, and an outlet port for gas outflow. The flow field channel region is located within the activation region of a single fuel cell cell; The exit bridge area is equipped with an anti-backflow structure to prevent liquid water from the public pipeline outside the fuel cell from entering the fuel cell. The input gas of the fuel cell enters the flow field channel area through the inlet bridge area from the inlet pipe. Inside the fuel cell, an electrochemical reaction occurs to generate water. The remaining gas and the generated water flow out of the fuel cell through the outlet bridge area and the outlet pipe in sequence, and flow to the common pipeline. The anti-backflow structure further includes a unidirectional valve structure located within the outlet bridge area; and... The opening direction of the unidirectional valve structure is such that it connects the inside of the fuel cell to the common pipeline, and its closing direction is such that it closes the connection between the inside of the fuel cell and the common pipeline.

2. The fuel cell bipolar plate with anti-backflow function according to claim 1, characterized in that, The number of the unidirectional valve structures is multiple; and... All unidirectional valve structures are equidistantly distributed within the outlet bridge area, and their spacing is designed so that when all unidirectional valve structures are closed, the internal channel of the fuel cell to the common pipeline is completely shut off.

3. The fuel cell bipolar plate with anti-backflow function according to claim 1, characterized in that, The number of the unidirectional valve structures is more than one; and... All one-way valve structures are distributed only on the lower side of the outlet bridge area, while there are no one-way valve structures on the higher side of the outlet bridge area, so that liquid water in the public pipeline is difficult to flow back into the fuel cell.

4. The fuel cell bipolar plate with anti-backflow function according to claim 2 or 3, characterized in that, Each one-way valve structure is a dome structure arranged along the fluid direction. This dome structure consists of three or more equally divided valves. When no fluid is flowing through, the valves are at an angle of 5° to 60° to the water flow direction, and the distance between adjacent valves is 1 to 5 mm. The height of the valves... h The thickness is 0.1~1.5mm.

5. The fuel cell bipolar plate with anti-backflow function according to any one of claims 1-3, characterized in that, The edge region of the anode plate is provided with an anode plate sealing groove, and the edge region of the cathode plate is provided with a cathode plate sealing groove; furthermore... An anode single-plate sealing strip is also provided in the anode single-plate sealing groove; a cathode single-plate sealing strip is also provided in the cathode single-plate sealing groove. The anode plate and cathode plate are also provided with at least two positioning holes.

6. The fuel cell bipolar plate with anti-backflow function according to any one of claims 1-3, characterized in that, The bipolar plate is sequentially provided with an inlet port for gas inflow, an inlet bridging area, an inlet distribution area, a flow field channel area, an outlet distribution area, an outlet bridging area, and an outlet port for gas outflow; and, Both the inlet and outlet distribution areas are equipped with a dot-matrix raised structure to ensure uniform gas flow.

7. The fuel cell bipolar plate with anti-backflow function according to any one of claims 1-3, characterized in that, The flow field channel region includes the anode flow field channel region located on the anode plate and the cathode flow field channel region located on the cathode plate; wherein, Both the anode flow field channel region and the cathode flow field channel region are wave-shaped reaction regions; the wave period and amplitude of the anode flow field channel region and the cathode flow field channel region are the same, and the wave peaks and troughs are arranged alternately between the two.

8. The fuel cell bipolar plate with anti-backflow function according to claim 5, characterized in that, When there are two positioning holes, the two positioning holes are diagonally distributed.

9. The fuel cell bipolar plate with anti-backflow function according to any one of claims 1-3, characterized in that, The anode plate has a bonding groove area on the side facing the cathode plate, used to bond the anode plate and cathode plate and seal the coolant flow channel area; and... The anode plate has a sealing groove area on the side facing away from the cathode plate, and the cathode plate has a sealing groove area on the side facing away from the anode plate, which is used to seal the fuel flow field channel area and the air flow field channel area.

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