Air-cooled cooling structure of closed proton exchange membrane fuel cell and assembly method

Abstract

The invention belongs to the technical field of fuel cell cooling, and particularly relates to a closed proton exchange membrane fuel cell air-cooled cooling structure and an assembly method.The closed proton exchange membrane fuel cell air-cooled cooling structure structurally comprises an air cooling plate, a first pole plate is fixedly connected to the top of the air cooling plate, and a second pole plate is fixedly connected to the bottom of the air cooling plate; the polar plate I and the polar plate II are both of a continuous bending structure; the air cooling plate comprises a continuous bending plate, the continuous bending plate is of a continuous bending structure, a plurality of n-shaped protrusions are arranged on the continuous bending plate, a gap is formed between every two adjacent n-shaped protrusions, a plurality of upper grooves are formed in the tops of the n-shaped protrusions at equal intervals, and a plurality of lower grooves are formed in the horizontal section of the continuous bending plate at equal intervals. Coolant flow channels are defined between every two adjacent [-shaped protrusions, the bottom wall of the first polar plate and the top wall of the second polar plate, and the bottom protrusions of the first polar plate and the top protrusions of the second polar plate form variable-diameter flow channels in the coolant flow channels.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel cell cooling, and in particular relates to an air-cooling structure and an assembly method for a closed proton exchange membrane fuel cell. Background Art

[0002] With the continuous development of fuel cell technology, especially its increasing application in high-performance equipment such as electric vehicles and drones, the cooling system of fuel cells has become one of the key factors to ensure its stable and efficient operation. In proton exchange membrane fuel cells (PEMFCs), the internal reaction of the stack will generate a lot of heat. If the heat is not effectively dissipated, it will directly affect the efficiency, life and safety of the battery. Traditional cooling methods, such as liquid cooling systems, have certain limitations in terms of complexity, cost and maintenance. Therefore, the development of a simpler and more efficient cooling solution has become an urgent problem to be solved.

[0003] As an innovative cooling solution, the closed air cooling system has gradually become a research hotspot for fuel cell cooling because it does not rely on liquid coolants but exchanges heat through air flow. In this system, air enters the battery stack through a carefully designed flow channel, takes away the heat generated during the operation of the battery stack, and keeps the battery temperature within an appropriate range. The key to the structural design of the closed air cooling system lies in the optimization of the flow field, including the selection of airflow paths, the layout of cooling channels, and the configuration of fans and heat sinks. A reasonable flow field structure can ensure uniform distribution of airflow, improve heat dissipation efficiency, and avoid the occurrence of local overheating.

[0004] However, the heat dissipation efficiency of the existing closed air-cooling system needs to be improved. Therefore, in order to further improve the cooling efficiency, we continuously innovate in the flow channel design and propose a closed proton exchange membrane fuel cell air-cooling cooling structure and assembly method. Summary of the invention

[0005] The purpose of the present invention is to provide a closed proton exchange membrane fuel cell air-cooling cooling structure and an assembly method to solve the above problems.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The closed proton exchange membrane fuel cell air-cooling cooling structure comprises:

[0008] An air-cooling plate, wherein a first pole plate is fixedly connected to the top of the air-cooling plate, and a second pole plate is fixedly connected to the bottom of the air-cooling plate, and both the first pole plate and the second pole plate have a continuous bending structure;

[0009] The air cooling plate comprises:

[0010] Continuous bending plate, the continuous bending plate is a continuous bending structure, and a number of U-shaped protrusions are provided on the continuous bending plate. There is a gap between two adjacent U-shaped protrusions. A number of upper grooves are equidistantly arranged on the top of the U-shaped protrusion, and a number of lower grooves are equidistantly arranged on the horizontal section of the continuous bending plate;

[0011] Between two adjacent U-shaped protrusions, the bottom wall of the first plate and the top wall of the second plate enclose a coolant flow channel, and the protrusion at the bottom of the first plate / the protrusion at the top of the second plate forms a variable cross-section flow channel in the coolant flow channel;

[0012] The first plate is fixed to the top of the air-cooled plate through the upper groove, and the second plate is fixed to the bottom of the air-cooled plate through the lower groove.

[0013] Optionally, the first plate and the second plate have the same structure;

[0014] The protrusion of the first plate matches the structure of the upper groove, and the protrusion of the second plate matches the structure of the lower groove;

[0015] The protrusion of the first plate matches the number of the upper grooves and corresponds one by one, and the protrusion of the first plate is embedded in the corresponding upper groove;

[0016] The protrusion of the second plate matches the number of the lower grooves and corresponds one by one, and the protrusion of the second plate is embedded in the corresponding lower groove.

[0017] Optionally, the cross-section of the upper groove / the lower groove adopts one of a rectangular structure, a trapezoidal structure, and a triangular structure.

[0018] Optionally, the upper grooves and the lower grooves are arranged in one-to-one correspondence.

[0019] Optionally, the upper grooves and the lower grooves are arranged in a staggered manner.

[0020] Optionally, the distance between two adjacent coolant flow channels is 0.6 mm - 1.5 mm.

[0021] Optionally, the depth of the coolant flow channel is 0.2 mm - 0.45 mm.

[0022] Optionally, the degree of staggered dispersion of the upper grooves and the lower grooves is 10% - 25%.

[0023] Assembly method of the air-cooled cooling structure of the closed proton exchange membrane fuel cell, using the above-mentioned air-cooled cooling structure of the closed proton exchange membrane fuel cell, including the following steps:

[0024] Horizontally push several protrusions at the bottom of the first plate into the corresponding upper grooves, so that the first plate is fitted and fixed to the top of the air-cooled plate;

[0025] Horizontally push several protrusions at the top of the second plate into the corresponding lower grooves, so that the second plate is fitted and fixed to the bottom of the air-cooled plate.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] During use, through the mutual nesting and fitting of the upper grooves / lower grooves provided on the air-cooled plate and the flow channels provided on the first plate / second plate, the contact area between the cooling flow field ridges and the first plate / second plate is increased, the contact resistance is effectively reduced, and the performance of the battery is improved; the nested groove structure forms a tight mechanical connection. In the actual operating conditions of the fuel cell, it will face many external forces such as vibrations and impacts. Such a design can effectively prevent the relative displacement between the plate and the cooling flow field ridges, greatly improving the mechanical stability of the battery. The assembly method of the groove structure and the plate flow channels makes the plate flow channels closer to the cooling flow field. The staggered protrusion structure of the flow channels increases the disturbance of the coolant at the flow field ridges, destroys the boundary layer, and plays a "turbulent flow" effect for the transmission and uniform diffusion of the coolant, enhancing the heat and mass transfer efficiency, and being beneficial to the heat dissipation of the battery and the transmission of reactants. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings:

[0029] Figure 1 It is a schematic structural diagram of the present invention;

[0030] Figure 2 It is a schematic structural diagram of the present invention from another angle;

[0031] Figure 3 It is a schematic structural diagram of the air-cooled plate of the present invention;

[0032] Figure 4 It is a sectional view of the structure of the present invention;

[0033] Figure 5 It is a schematic diagram of the cooling gas flow direction of the present invention;

[0034] Figure 6 It is a schematic structural diagram of the variable cross-section flow channel of the present invention;

[0035] Figure 7This is a comparison chart of the impact resistance performance of the stack structure of the present invention;

[0036] Figure 8 This is a comparison chart of the heat dissipation performance of the stack of the present invention;

[0037] Among them, 1 is an air-cooled plate; 2 is the first electrode plate; 3 is the second electrode plate; 11 is a C-shaped protrusion; 12 is an upper groove; 13 is a lower groove; 14 is a coolant flow channel; 15 is a continuously bent plate; 16 is a horizontal section; 17 is a variable flow channel. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0040] Referring to Figures 1 to 8 , the present invention discloses an air-cooled cooling structure for a closed proton exchange membrane fuel cell, including:

[0041] An air-cooled plate 1, the top of the air-cooled plate 1 is fixedly connected with a first electrode plate 2, the bottom of the air-cooled plate 1 is fixedly connected with a second electrode plate 3, and both the first electrode plate 2 and the second electrode plate 3 are continuously bent structures;

[0042] The air-cooled plate 1 includes:

[0043] A continuously bent plate 15, the continuously bent plate 15 is a continuously bent structure, a plurality of C-shaped protrusions 11 are arranged on the continuously bent plate 15, there is a gap between adjacent two C-shaped protrusions 11, a plurality of upper grooves 12 are arranged at equal intervals on the top of the C-shaped protrusions 11, and a plurality of lower grooves 13 arranged at equal intervals are arranged on the horizontal section 16 of the continuously bent plate 15;

[0044] A coolant flow channel 14 is formed by enclosing between adjacent two C-shaped protrusions 11, the bottom protrusion of the first electrode plate 2 / the top protrusion of the second electrode plate 3 forms a variable flow channel 17 in the coolant flow channel 14;

[0045] The first electrode plate 2 is fixedly embedded in the top of the air-cooled plate 1 through the upper groove 12, and the second electrode plate 3 is fixedly embedded in the bottom of the air-cooled plate 1 through the lower groove 13.

[0046] During use, the upper groove 12 / lower groove 13 provided on the air-cooled plate 1 and the flow channels provided on the first electrode plate 2 / second electrode plate 3 are nested and fitted with each other, increasing the contact area between the cooling flow field ridges and the first electrode plate 2 / second electrode plate 3, effectively reducing the contact resistance, and improving the performance of the battery; the nested structure of the grooves forms a tight mechanical connection. In the actual operating conditions of the fuel cell, it will face many external forces such as vibrations and impacts. Such a design can effectively prevent the relative displacement between the electrode plate and the cooling flow field ridges, greatly improving the mechanical stability of the battery. The assembly method of the groove structure and the electrode plate flow channels makes the electrode plate flow channels closer to the cooling flow field. The staggered convex structure of the flow channels increases the disturbance of the coolant at the flow field ridges, destroys the boundary layer, and plays a "turbulent flow" effect for the transmission and uniform diffusion of the coolant, enhancing the heat and mass transfer efficiency, and being beneficial to battery heat dissipation and reactant transmission.

[0047] As an alternative embodiment, the first electrode plate 2 and the second electrode plate 3 have the same structure;

[0048] The protrusions of the first electrode plate 2 match the structure of the upper groove 12, and the protrusions of the second electrode plate 3 match the structure of the lower groove 13;

[0049] The protrusions of the first electrode plate 2 match the number of the upper grooves 12 and correspond one by one, and the protrusions of the first electrode plate 2 are embedded in the corresponding upper grooves 12;

[0050] The protrusions of the second electrode plate 3 match the number of the lower grooves 13 and correspond one by one, and the protrusions of the second electrode plate 3 are embedded in the corresponding lower grooves 13.

[0051] As an alternative embodiment, the cross-section of the upper groove 12 / lower groove 13 adopts one of a rectangular structure, a trapezoidal structure, and a triangular structure.

[0052] As an alternative embodiment, the upper grooves 12 and the lower grooves 13 are arranged in one-to-one correspondence.

[0053] As an alternative embodiment, the upper grooves 12 and the lower grooves 13 are arranged in a staggered manner.

[0054] As an alternative embodiment, the distance between two adjacent coolant flow channels 14 is 0.6 mm - 1.5 mm.

[0055] As an alternative embodiment, the depth of the coolant flow channel 14 is 0.2 mm - 0.45 mm.

[0056] As an alternative embodiment, the degree of staggered dispersion of the upper grooves 12 and the lower grooves 13 is 10% - 25%.

[0057] The main features of the above device are reflected in the cooling flow field of the air-cooled plate 1 and the first electrode plate 2 / second electrode plate 3:

[0058] The shapes, sizes, and distributions of the upper grooves 12 / lower grooves 13 are optimized according to specific application scenarios. For example, shapes such as rectangles, trapezoids, and triangles can be adopted.

[0059] The depths, widths, and spacings of the upper grooves 12 / lower grooves 13 can be adjusted according to the requirements of contact resistance, mechanical stability, and heat and mass transfer.

[0060] The upper grooves 12 / lower grooves 13 of the present invention are provided on the cooling flow field ridges of the air-cooled plate 1, and the first electrode plate 2 / second electrode plate 3 are respectively nested and assembled with the air-cooled plate 1 through the upper grooves 12 / lower grooves 13.

[0061] Since the shapes of the electrode plates are mostly rectangular with rounded corners, the channel spacing is between 0.6 mm and 1.5 mm, and the channel depth can be between 0.2 mm and 0.45 mm. Therefore, in the present invention, it is preferably that the width and spacing of the coolant channels 14 are both 1 mm, and the height is 0.35 mm.

[0062] Let the upper and lower fillet radii of the upper grooves 12 / lower grooves 13 be represented by R1 and R2. Considering the accuracy of the stamping process and the manufacturing difficulty of the electrode plates, the values of the fillet radii are different. Generally, the upper fillet radius is 30% to 60% larger than the lower fillet, and the fillet radius is set according to the channel height, generally 50% of the channel height. Thus, the upper fillet R1 is set to 0.2 mm, and the lower fillet is set to 0.1 mm.

[0063] The height of the groove depth on the air-cooled plate 1 will affect the stability of the entire stack assembly process and the performance. Through numerical simulation combined with experimental comparison research, it is found that the best groove depth is 25% of the punch height, which is 0.25 mm. The upper grooves 12 and lower grooves 13 on the air-cooled plate 1 can be arranged staggered with each other to form an air flow cooling channel similar to a snake shape. The best cooling effect is generally within 10% to 25% of the staggered discrete degree. They can also be distributed directly opposite to form a variable-diameter gourd-shaped cooling channel. The cooling effects of the two distribution methods are similar. The above design parameters consider the requirements of mechanical stability. This design can completely nest the electrode plate and the cooling plate together to form a tight mechanical connection.

[0064] Through the setting of the groove structure, the channels on the first electrode plate 2 / second electrode plate 3 can be embedded inside the cooling flow field. The convex structure of the channels adapts to the cooling mechanism, increasing the disturbance of the coolant at the flow field and breaking the boundary layer.

[0065] An assembly method for the air-cooled cooling structure of a closed proton exchange membrane fuel cell, using the above-mentioned air-cooled cooling structure of a closed proton exchange membrane fuel cell, includes the following steps:

[0066] Horizontally push several protrusions at the bottom of the first electrode plate 2 into the corresponding upper grooves 12 respectively, so that the first electrode plate 2 is fitted and fixed with the top of the air-cooled plate 1;

[0067] Push the protrusions on the top of the second pole plate 3 horizontally into the corresponding lower grooves 13 , so that the second pole plate 3 is embedded and fixed with the bottom of the air-cooling plate 1 .

[0068] Application Example 1:

[0069] The 0.25 mm deep grooves punched out at the flow channel ridges of the electrode plate 1 2 / electrode plate 2 3 are arranged in an array with an interval of 1 mm; the upper rounded corner of each groove is 0.2 mm, and the lower rounded corner is 0.1 mm. The flow channel ridges of the electrode plate 1 2 and the electrode plate 2 3 are staggered with the flow channel ridges of the air-cooled plate 1.

[0070] The pole plate 1 2, pole plate 2 3 and air cooling plate 1 are staggered so that all the flow channels on pole plate 1 2 / pole plate 2 3 can be assembled one by one in the grooves on the air cooling plate 1 to achieve a tightening effect. Through the design of the upper groove 12 / lower groove 13 and chamfers on pole plate 1 2 / pole plate 2 3 and air cooling plate 1, the contact area between the two is increased, which helps to reduce the contact resistance and greatly improves the performance of the battery. During the disassembly and assembly process, the air cooling plate 1 can be fixed, and then one end of pole plate 1 2 can be slowly pushed from left to right into the upper groove 12 in the direction perpendicular to the cooling flow field. Due to the existence of the chamfer, pole plate 1 2 can be easily assembled with the air cooling plate 1 with a small gap. Similarly, the assembly of pole plate 2 3 is also the same.

[0071] With the design of the upper groove 12 / lower groove 13, the cooling gas introduced from the left side will experience a gas channel with a variable diameter, changing from an air flow channel diameter of 1mm to 0.6mm and then to 1mm, and so on. After multiple changes in diameter, the cooling gas will experience air flow disturbances at the ridges, destroying the boundary layer and thus forming turbulence, which plays a key role in the diffusion and transmission of the cooling gas, greatly enhancing heat and mass transfer and improving the overall heat dissipation performance of the battery.

[0072] The design of the groove structure plays a favorable role in enhancing the stability of the plate assembly and the heat dissipation effect. With the groove design, the lateral displacement of the flow channel ridge in the face of random vibration and 40KN impact under working conditions is about 81% smaller than that of the traditional plate, which greatly enhances the stability of the battery stack performance. The turbulence effect generated by the groove also provides a better heat dissipation effect for the plate, reducing the heat dissipation temperature by 1.92℃ compared with the traditional plate.

[0073] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0074] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. Closed proton exchange membrane fuel cell air-cooled cooling structure, characterized in that, Including: An air-cooled plate (1), a first electrode plate (2) is fixedly connected to the top of the air-cooled plate (1), a second electrode plate (3) is fixedly connected to the bottom of the air-cooled plate (1), and both the first electrode plate (2) and the second electrode plate (3) are of a continuous bending structure; The air-cooled plate (1) includes: A continuous bending plate (15), the continuous bending plate (15) is of a continuous bending structure, a plurality of U-shaped protrusions (11) are arranged on the continuous bending plate (15), there is a gap between two adjacent U-shaped protrusions (11), a plurality of upper grooves (12) are arranged at equal intervals on the top of the U-shaped protrusion (11), and a plurality of lower grooves (13) arranged at equal intervals are arranged on the horizontal section (16) of the continuous bending plate (15); A coolant flow channel (14) is formed by enclosing between two adjacent U-shaped protrusions (11), the bottom protrusion of the first electrode plate (2) / the top protrusion of the second electrode plate (3) forms a variable flow channel (17) in the coolant flow channel (14); The first electrode plate (2) is fixedly embedded in the top of the air-cooled plate (1) through the upper grooves (12), and the second electrode plate (3) is fixedly embedded in the bottom of the air-cooled plate (1) through the lower grooves (13).

2. The closed proton exchange membrane fuel cell air-cooled cooling structure according to claim 1, wherein: The first electrode plate (2) and the second electrode plate (3) have the same structure; The protrusion of the first electrode plate (2) matches the structure of the upper groove (12), and the protrusion of the second electrode plate (3) matches the structure of the lower groove (13); The protrusion of the first electrode plate (2) matches the number of the upper grooves (12) and corresponds one by one, and the protrusion of the first electrode plate (2) is embedded in the corresponding upper groove (12); The protrusion of the second electrode plate (3) matches the number of the lower grooves (13) and corresponds one by one, and the protrusion of the second electrode plate (3) is embedded in the corresponding lower groove (13).

3. The closed proton exchange membrane fuel cell air-cooled cooling structure according to claim 1, characterized in that: The cross-section of the upper groove (12) / the lower groove (13) adopts one of a rectangular structure, a trapezoidal structure, and a triangular structure.

4. The air-cooled cooling structure of the closed proton exchange membrane fuel cell according to claim 1, wherein: The upper grooves (12) and the lower grooves (13) are arranged in one-to-one correspondence.

5. The closed proton exchange membrane fuel cell air-cooled cooling structure according to claim 1, characterized in that: The upper grooves (12) and the lower grooves (13) are arranged in a staggered manner.

6. The closed proton exchange membrane fuel cell air-cooled cooling structure according to claim 1, characterized in that: The distance between two adjacent coolant flow channels (14) is 0.6 mm - 1.5 mm.

7. The air-cooled cooling structure of the closed proton exchange membrane fuel cell according to claim 1, wherein: The depth of the coolant flow channel (14) is 0.2 mm - 0.45 mm.

8. The closed proton exchange membrane fuel cell air-cooled cooling structure according to claim 5, wherein: The degree of staggered discreteness of the upper grooves (12) and the lower grooves (13) is 10% - 25%.

9. Assembly method of the air-cooled cooling structure of a closed proton exchange membrane fuel cell, using the air-cooled cooling structure of the closed proton exchange membrane fuel cell according to any one of claims 1-8, characterized in that, Including the following steps: Horizontally push a plurality of protrusions at the bottom of the first electrode plate (2) into the corresponding upper grooves (12) respectively, so that the first electrode plate (2) is embedded and fixed with the top of the air-cooled plate (1); Horizontally push a plurality of protrusions at the top of the second electrode plate (3) into the corresponding lower grooves (13) respectively, so that the second electrode plate (3) is embedded and fixed with the bottom of the air-cooled plate (1).

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