Bipolar plate for fuel cell
By introducing a bridge-shaped annular protrusion platform, a U-shaped groove, and a recessed point into the bridge structure of the fuel cell bipolar plate, the problem of reduced sealing performance caused by bridge structure collapse was solved, achieving higher sealing performance and assembly efficiency.
Patent Information
- Application Number
- CN202423266435.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2034-12-30
AI Technical Summary
In existing fuel cells, the bridge structure lacks rigidity and is prone to collapse, leading to decreased sealing performance and easy cross-flow or leakage of reactant gases.
A bipolar plate for fuel cells is designed to enhance structural strength by introducing a bridge-shaped annular raised platform, a U-shaped groove, and a recessed point into the bridge structure. The U-shaped groove and recessed point are set on the coolant annular raised platform to support the bridge structure and prevent collapse.
It improves the sealing performance of fuel cells, prevents cross-flow or leakage of reactant gases, enhances assembly efficiency, and improves the overall structural strength of bipolar plates.
Smart Images
Figure CN223858149U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to fuel cell technical field, concretely relates to a bipolar plate for fuel cell. BACKGROUND
[0002] Fuel cell as a kind of efficient, clean energy conversion device, in numerous fields has shown tremendous application potential.In fuel cell stack, reaction gas (hydrogen and oxygen) passes through electrochemical reaction, generates electric energy, heat energy and water, and the heat energy generated is dissipated by coolant.Fuel cell stack core component includes bipolar plate (including anode plate, cathode plate) and membrane electrode, and the sealing space formed between bipolar plate and membrane electrode plays a vital role for the normal operation of fuel cell.Each fluid is separated by sealing ring in sealing space, to prevent cross flow or leakage, affect the performance and safety of fuel cell.
[0003] However, the existing fuel cell has the sealing leakage risk of sealing ring in the long-term service process of fuel cell.The bipolar plate is provided with several functional areas, including inlet and outlet area, bridge area, distribution area and active area.The bridge area of the back of anode plate and cathode plate is welded to form bridge structure, and reaction gas enters bridge structure from inlet and outlet area, then enters distribution area, active area on the front of anode plate or cathode plate in turn through bridge structure to occur electrochemical reaction.However, the current bridge structure is insufficient in rigidity, easy to collapse, reduces the sealing performance of fuel cell, thereby easily causing cross flow or leakage of reaction gas. UTILITY MODEL CONTENTS
[0004] The utility model aims at providing a kind of bipolar plate for fuel cell, by optimizing the design of the bridge structure of the bipolar plate, the strength of bridge structure is enhanced, to ensure the good sealing property of fuel cell in the long-term service process.
[0005] To achieve the above-mentioned purpose, the utility model provides a kind of bipolar plate for fuel cell, including anode plate, cathode plate, the bipolar plate is provided with several gas inlets and outlets, annular protrusion, strip protrusion, through-hole;Wherein,
[0006] The gas inlets and outlets include first gas inlets and outlets, second gas inlets and outlets;
[0007] The ring-shaped protrusion comprises a first ring-shaped protrusion and a second ring-shaped protrusion, the first ring-shaped protrusion is arranged outside the gas inlet and outlet, and the second ring-shaped protrusion is arranged outside the first ring-shaped protrusion; a bridge ring-shaped protrusion platform is formed between the first ring-shaped protrusion and the second ring-shaped protrusion, the bridge ring-shaped protrusion platform is higher than the bipolar plate reference surface and is not higher than the ring-shaped protrusion; a U-shaped groove is arranged around the first ring-shaped protrusion on the bridge ring-shaped protrusion platform, and an opening is formed between the two ends of the U-shaped groove, and the extension direction of the opening is the same as the gas flow direction;
[0008] The strip-shaped protrusion comprises an inner strip-shaped protrusion and an outer strip-shaped protrusion; the inner strip-shaped protrusion is arranged between the gas inlet and outlet and the first ring-shaped protrusion along the extension direction of the opening; the outer strip-shaped protrusion comprises a first outer strip-shaped protrusion and a second outer strip-shaped protrusion; the first outer strip-shaped protrusion is arranged at the outer edge of the second ring-shaped protrusion outside the first gas inlet and outlet on the cathode plate along the extension direction of the opening; the second outer strip-shaped protrusion is arranged at the outer edge of the second ring-shaped protrusion outside the second gas inlet and outlet on the anode plate along the extension direction of the opening;
[0009] The through hole comprises an anode plate through hole and a cathode plate through hole; the anode plate through hole is arranged at the outer edge of the second ring-shaped protrusion outside the first gas inlet and outlet on the anode plate along the extension direction of the opening; the cathode plate through hole is arranged at the outer edge of the second ring-shaped protrusion outside the second gas inlet and outlet on the cathode plate along the extension direction of the opening.
[0010] Optionally, the bottom of the U-shaped groove is flush with the bipolar plate reference surface.
[0011] Optionally, the opening between the two ends of the U-shaped groove is provided with a plurality of recessed points, and a channel extending in the gas flow direction is formed between adjacent recessed points.
[0012] Optionally, the bottom of the recessed point is flush with the bipolar plate reference surface.
[0013] Optionally, the anode plate and the cathode plate are further provided with a coolant inlet and outlet; the ring-shaped protrusion further comprises a third ring-shaped protrusion and a fourth ring-shaped protrusion;
[0014] The third ring-shaped protrusion is arranged outside the coolant inlet, the fourth ring-shaped protrusion is arranged outside the third ring-shaped protrusion, and a coolant ring-shaped protrusion platform is formed between the third ring-shaped protrusion and the fourth ring-shaped protrusion; a U-shaped groove is arranged around the third ring-shaped protrusion on the coolant ring-shaped protrusion platform;
[0015] A coolant flow guide strip-shaped protrusion is arranged between the coolant inlet and outlet and the third ring-shaped protrusion.
[0016] Optionally, a plurality of recessed points are arranged between the two ends of the U-shaped groove on the coolant annular raised platform, and a channel extending along the flow direction of the coolant is formed between adjacent recessed points.
[0017] Optionally, the bipolar plate comprises a coolant distribution area, and the outer edge of the fourth annular raised platform is connected to the coolant distribution area, and a plurality of outer recessed points are arranged at the connection between the outer edge of the fourth annular raised platform and the coolant distribution area, and a channel extending along the flow direction of the coolant is formed between adjacent outer recessed points.
[0018] Optionally, the first annular raised platform and the second annular raised platform have the same width and height.
[0019] Optionally, the distance between the first annular raised platform and the gas inlet and outlet is 0.5mm-1.5mm.
[0020] Optionally, the distance between the second annular raised platform and the first annular raised platform is 3mm-5mm.
[0021] Compared with the prior art, the bipolar plate has the following beneficial effects:
[0022] In the utility model, the bridge structure in the bipolar plate is composed of the anode plate, the cathode plate, the bridge annular raised platform, the strip-shaped raised platform (the inner strip-shaped raised platform and the outer strip-shaped raised platform) and the through hole, the reaction gas enters the bridge cavity formed between the bridge annular raised platforms of the bipolar plate from the gas inlet and outlet through the inner cavity of the inner strip-shaped raised platform, then flows into the inner cavity of the outer strip-shaped raised platform of a monopolar plate, and then flows out through the through hole of another monopolar plate and enters the distribution area on the front face.
[0023] Further, a plurality of recessed points are arranged on the bridge annular raised platform, the bottom of the recessed points is flush with the reference surface of the bipolar plate, and the bridge annular raised platform is further supported.
[0024] Further, a coolant annular raised platform is arranged on the bipolar plate, and the coolant annular raised platform is also provided with a U-shaped groove and a recessed point, so as to enhance the structural strength of the coolant annular raised platform and the structural strength of the bipolar plate. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1A partial structure diagram of the inlet side and the outlet side of the positive plate of a bipolar plate.
[0026] Figure 2 A partial structure diagram of the inlet side and the outlet side of the negative plate of a bipolar plate.
[0027] Figure 3 For Figure 2 A partial sectional view of a bipolar plate along the a-a' direction.
[0028] Figure 4 A partial structure diagram of the inlet side and the outlet side of the positive plate of a bipolar plate.
[0029] Figure 5 An exploded view of a bipolar plate (including a sealing ring).
[0030] BRIEF DESCRIPTION OF DRAWINGS
[0031] Gas inlet and outlet 10
[0032] First gas inlet 11
[0033] First gas outlet 11'
[0034] Second gas inlet 12
[0035] Second gas outlet 12'
[0036] Finger-shaped flow channel 20
[0037] Annular protrusion 30
[0038] First annular protrusion 31
[0039] Second annular protrusion 32
[0040] Third annular protrusion 33
[0041] Fourth annular protrusion 34
[0042] Strip-shaped protrusion 40
[0043] Inner strip-shaped protrusion 41
[0044] Outer strip-shaped protrusion 42
[0045] Coolant flow guide strip-shaped protrusion 43
[0046] First outer strip-shaped protrusion 421
[0047] Second outer strip-shaped protrusion 422
[0048] Through hole 50
[0049] Anode plate through hole 51
[0050] Cathode plate through hole 52
[0051] Bridge ring protrusion platform 60
[0052] U-shaped groove 61
[0053] U-shaped groove first end 611
[0054] U-shaped groove second end 612
[0055] Recess point 62
[0056] Coolant inlet 71
[0057] Coolant outlet 71'
[0058] Coolant ring protrusion platform 80
[0059] Coolant distribution area 90
[0060] Outer recess point 91
[0061] Sealing ring limiting protrusion 100
[0062] First sealing ring limiting protrusion 101
[0063] Second sealing ring limiting protrusion 102
[0064] Polar plate sealing groove 110
[0065] Polar plate sealing ring 120
[0066] Anode side sealing ring 121
[0067] Cathode side sealing ring 122
[0068] Gas inlet and outlet sealing ring 130
[0069] First gas inlet and outlet sealing ring 131
[0070] Second gas inlet and outlet sealing ring 132
[0071] Coolant inlet and outlet sealing ring 140 DETAILED DESCRIPTION
[0072] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0073] In the description of the utility model, it needs to explain, the term "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or position relation is based on the orientation or position relation shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the device or element must have a particular orientation, a particular orientation and operation, therefore, it cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0074] In the description of the utility model, it needs to explain, unless otherwise expressly provided and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0075] The monopolar plate described herein refers to the anode plate or the cathode plate.
[0076] The protrusions and recesses described herein are relative to the front surface of the monopolar plate.
[0077] The bipolar plate reference surface described herein refers to the lowest plane of the anode plate or the cathode plate.
[0078] The working principle of the fuel cell described herein is that hydrogen oxidation reaction occurs on the anode, and air or oxygen reduction reaction occurs on the cathode, generating electric energy, heat energy, and water. The heat energy is dissipated by the coolant.
[0079] As described in the background, the existing fuel cell has a long-term service sealing leakage risk. The utility model finds that the main reasons for the sealing leakage risk are as follows:
[0080] In the existing fuel cell, the structure of "two plates and three cavities" is adopted, and the bridge area on the back of the cathode plate and the anode plate is welded together to form a bridge structure of the bipolar plate. The strength of the bridge structure is weak, and under the condition of the compression force of the sealing ring above the front surface of the monopolar plate, the bridge structure is easily pressed, causing the collapse of the suspended area in the bridge structure, so that the sealing ring cannot form a good resistance between the monopolar plates, and the reaction gas leaks. The two plates refer to the anode plate and the cathode plate; the three cavities refer to the hydrogen cavity formed between the anode plate and the membrane electrode, the air (or, oxygen) cavity formed between the cathode plate and the membrane electrode, and the coolant cavity formed between the anode plate and the cathode plate.
[0081] To address the aforementioned problems, this invention provides a bipolar plate for fuel cells, and more particularly, a bridging structure for the bipolar plate. This invention designs the bridging area of the bipolar plate using U-shaped grooves and recessed points to support the bridging protrusion platform, thereby enhancing the rigidity of the bridging structure. This ensures that the surface of the bridging area facing the membrane electrode assembly (MEA) of the bipolar plate can form good contact with the sealing ring, preventing cross-flow or leakage of reactant gases. Furthermore, the bridging structure design of this invention ensures that the sealing ring structures on both sides of the bipolar plate are identical, allowing for direct alignment and assembly during the stacking of the bipolar plate and MEA without additional rotation, thus improving the assembly efficiency of the fuel cell.
[0082] The following explanation is based on the accompanying drawings.
[0083] like Figure 1 and Figure 2 As shown, the present invention provides a bipolar plate for a fuel cell, comprising an anode plate A and a cathode plate B, wherein the anode plate A and the cathode plate B are assembled by welding a specific area on their back sides to form the bipolar plate. Figure 1 and Figure 2 The diagrams show partial structural schematics of the front sides of the anode plate A and the cathode plate B, respectively.
[0084] The bipolar plate is provided with several gas inlets and outlets 10, annular protrusions 30, strip-shaped protrusions 40, and through holes 50. Wherein:
[0085] The gas inlet / outlet 10 includes a first gas inlet / outlet and a second gas inlet / outlet. The first gas inlet / outlet includes a first gas inlet 11 and a first gas outlet 11'; the second gas inlet / outlet includes a second gas inlet 12 and a second gas outlet 12'. The gas supplied to the first gas inlet 11 and the first gas outlet 11' is hydrogen; the gas supplied to the second gas inlet 12 and the second gas outlet 12' is air or oxygen. Finger-shaped flow channels 20 are provided on both the inlet side and the outlet side (exit side) of the anode plate A and the cathode plate B, forming the gas distribution area of the bipolar plate.
[0086] The ring-shaped protrusion 30 comprises a first ring-shaped protrusion 31 and a second ring-shaped protrusion 32, the first ring-shaped protrusion 31 is arranged outside the gas inlet and outlet 10, and the second ring-shaped protrusion 32 is arranged outside the first ring-shaped protrusion 31. In this example, the distance between the first ring-shaped protrusion 31 and the edge of the gas inlet and outlet 10 is 0.5mm-1.5mm; the distance between the second ring-shaped protrusion 32 and the first ring-shaped protrusion 31 is 3mm-5mm. The width and height of the first ring-shaped protrusion 31 and the second ring-shaped protrusion 32 are the same, and the height of the first ring-shaped protrusion 31 and the second ring-shaped protrusion 32 is the same as the height of the finger-shaped flow channel 20 on the bipolar plate, which is beneficial to uniform dispersion of pressure and reduces the risk of structural deformation. In this example, the width of the first ring-shaped protrusion 31 and the second ring-shaped protrusion 32 is 0.5mm-1mm, and the height is 2.5mm-4mm.
[0087] The first ring-shaped protrusion 31 and the second ring-shaped protrusion 32 form a bridge ring-shaped protrusion platform 60. The surface of the bridge ring-shaped protrusion platform 60 is higher than the bipolar plate reference surface (the lowest plane of the anode plate A and / or the cathode plate B), so that in the bipolar plate, the bridge ring-shaped protrusion platform 60 of the anode plate A and the bridge ring-shaped protrusion platform 60 of the cathode plate B form a bridge cavity for reaction gas flow. The height of the bridge ring-shaped protrusion platform 60 is not higher than the height of the ring-shaped protrusion 30, so as to form a gas inlet and outlet sealing groove defined by the bottom of the bridge ring-shaped protrusion platform 60 and the side wall of the ring-shaped protrusion 30, for injection or pasting of a gas inlet and outlet sealing ring. In this example, the bridge ring-shaped protrusion platform 60 is 1.5mm-2.5mm higher than the bipolar plate reference surface, and preferably, the height of the bridge ring-shaped protrusion platform 60 is half of the height of the ring-shaped protrusion 30.
[0088] On the bridge ring-shaped protrusion platform 60, a U-shaped groove 61 is arranged around part of the first ring-shaped protrusion 31, the U-shaped groove 61 is a non-closed ring structure, which comprises a U-shaped groove first end 611 and a U-shaped groove second end 612, and an opening is formed between the U-shaped groove first end 611 and the U-shaped groove second end 612, the extension direction of the opening is the same as the gas flow direction. In the bridge cavity of the bipolar plate, the U-shaped groove first end 611 and the U-shaped groove second end 612 are provided for reaction gas to pass through. The bottom of the U-shaped groove 61 is flush with the bipolar plate reference surface, so that the bottoms of the U-shaped grooves 61 at opposite positions on two monopolar plates can abut against each other, providing support for the bridge ring-shaped protrusion platform 60, dispersing pressure, preventing the bridge ring-shaped protrusion platform 60 from collapsing due to the compression of the gas inlet and outlet sealing ring, affecting the reaction gas flow in the bridge cavity, and causing the reaction gas to leak between the bridge ring-shaped protrusion platform 60 and its adjacent membrane electrode. In this example, the width of the U-shaped groove 61 is 0.5mm-1mm.
[0089] In the present example, a plurality of recessed points 62 are arranged between the first end 611 and the second end 612 of the U-shaped groove 61. The recessed points 62 are regularly arranged, and the channels for the reaction gas to pass through are formed between the recessed points 62 in the bridge cavity of the bipolar plate, thereby playing a flow guiding role to make the reaction gas be uniformly distributed. The bottoms of the recessed points 62 are flush with the reference plane of the bipolar plate, so that the bottoms of the recessed points 62 at the opposite positions on the two monopolar plates can abut against each other, thereby providing further support for the bridge annular protruding platform 60. The recessed points 62 can be circular, raindrop-shaped or horseshoe-shaped. In the present example, the recessed points 62 are circular, and the width and the depth of the recessed points 62 are the same as the width and the depth of the U-shaped groove 61, so that the recessed points 62 and the U-shaped groove 61 can resist the pressure generated when the gas inlet and outlet sealing rings are compressed at the same scale, and the two work together to provide uniform and consistent support force for the bridge annular protruding platform 60, thereby preventing the bridge annular protruding platform 60 from being deformed under stress.
[0090] In the present utility model, the strip-shaped protrusions 40 include inner side strip-shaped protrusions 41 and outer side strip-shaped protrusions 42. Adjacent inner side strip-shaped protrusions 41 are parallel to each other, and adjacent outer side strip-shaped protrusions 42 are parallel to each other. It should be noted that the strip-shaped protrusions 40 are relative to the front surface of the monopolar plate, and on the back surface of the monopolar plate, corresponding strip-shaped recesses are formed.
[0091] The inner side strip-shaped protrusions 41 are arranged between the gas inlet and outlet 10 and the first annular protrusion 31 along the extension direction of the opening, and the inner cavities of each inner side strip-shaped protrusion 41 are used for the reaction gas to pass through. Specifically, when the anode plate A back surface and the cathode plate B back surface are aligned and assembled, the spacing planes between the adjacent inner side strip-shaped protrusions 41 on the anode plate A and the spacing planes between the adjacent inner side strip-shaped protrusions 41 on the cathode plate B abut against each other, the inner side strip-shaped protrusions 41 on the anode plate A and the inner side strip-shaped protrusions 41 on the cathode plate B are mirror-symmetrical and correspond to each other, and a cavity is formed between the two, which forms a reaction gas flow channel. In the present example, the width of each inner side strip-shaped protrusion 41 is 1.0mm-2.0mm, and the height thereof is the same as that of the bridge annular protruding platform 60, i.e. 1.5mm-2.5mm.
[0092] The outer side strip-shaped protrusions 42 include first outer side strip-shaped protrusions 421 and second outer side strip-shaped protrusions 422. Referring to Figure 1 , the second outer side strip-shaped protrusions 422 are arranged at the outer edges of the second annular protrusion 32 outside the second gas inlet and outlet (12 and 12') on the anode plate A along the extension direction of the opening (formed between the two ends of the U-shaped groove 61). The inner cavities of the second outer side strip-shaped protrusions 422 are used for accommodating the reaction gas from the bridge cavity outside the second gas inlet and outlet. Referring toFigure 2 The first outer side strip-shaped protrusion 421 is arranged on the outer edge of the second annular protrusion 32 outside the first gas inlet and outlet (11 and 11') on the cathode plate B along the extension direction of the opening, and the inner cavity of the first outer side strip-shaped protrusion 421 is used for accommodating the reaction gas from the bridge cavity outside the first gas inlet and outlet. The first end of the outer side strip-shaped protrusion 42 is connected with the outer edge of the second annular protrusion 32, and the second end is directed to the gas distribution area on the bipolar plate. In this example, the distance between the second end of the outer side strip-shaped protrusion 42 and the gas distribution area on the bipolar plate is 1.5 mm to 3.5 mm. The second end of the outer side strip-shaped protrusion 42 and the gas distribution area on the bipolar plate form a welding area, which is used for welding and connecting the back surface of the anode plate A and the back surface of the cathode plate B. The welding position can effectively block the reaction gas flowing through the gas inlet and outlet 10 from entering the coolant cavity between the back surface of the anode plate A and the back surface of the cathode plate B. In this example, the diameter of each through hole 50 is 0.5 mm to 1.5 mm.
[0093] In the utility model, the through hole 50 includes an anode plate through hole 51 and a cathode plate through hole 52. The through hole 50 is used for the reaction gas to pass through. Figure 1 The anode plate through hole 51 is arranged on the outer edge of the second annular protrusion 32 outside the first gas inlet and outlet (11 and 11') on the anode plate A. Figure 2 The cathode plate through hole 52 is arranged on the outer edge of the second annular protrusion 32 outside the second gas inlet and outlet (12 and 12') on the cathode plate B.
[0094] The vertical projection of the anode plate through hole 51 on the anode plate A on the cathode plate B at least partially coincides with the position of the first outer side strip-shaped protrusion 421 on the cathode plate B, so that the anode plate through hole 51 is connected with the inner cavity of the first outer side strip-shaped protrusion 421, so that the reaction gas (hydrogen) entering the inner cavity of the first outer side strip-shaped protrusion 421 can flow into the front surface of the anode plate A through the anode plate through hole 51, and then sequentially enter the gas distribution area and the active area on the front surface of the anode plate A. The reaction gas occurs electrochemical reaction in the active area.
[0095] The vertical projection of the cathode plate through hole 52 on the cathode plate B on the anode plate A at least partially coincides with the position of the second outer side strip-shaped protrusion 422 on the anode plate A, so that the cathode plate through hole 52 is connected with the inner cavity of the second outer side strip-shaped protrusion 422, so that the reaction gas entering the inner cavity of the second outer side strip-shaped protrusion 422 can flow into the front surface of the cathode plate B through the cathode plate through hole 52, and then sequentially enter the gas distribution area and the active area on the front surface of the cathode plate B. The reaction gas occurs electrochemical reaction in the active area.
[0096] In this invention, the bridge structure is formed by the aforementioned strip-shaped protrusions 40 (inner strip-shaped protrusions 41 and outer strip-shaped protrusions 42), the bridge-shaped annular protrusion platform 60, and the through holes 50. See also, as an example. Figure 3 , Figure 3 It shows Figure 2 A magnified schematic diagram of a local cross-section of the bipolar plate along the a-a' direction. Figure 3 The bipolar plates in the middle have been welded together. When the second gas (air or oxygen) is introduced from the second gas inlet 12, the second gas enters the bridge cavity formed between the bridge ring protrusion platform 60 of the anode plate A and the cathode plate B from the cavity formed between the inner strip protrusion 41 of the anode plate A and the cathode plate B, flows into the inner cavity of the second outer strip protrusion 422 on the anode plate A, and then enters the front side of the cathode plate B through the cathode plate through hole 52 on the cathode plate B.
[0097] In this example, the anode plate A and cathode plate B are also provided with coolant inlets and outlets, which include a coolant inlet 71 and a coolant outlet 71', used to introduce and discharge coolant between the bipolar plates, respectively, to achieve heat dissipation. As an example, Figure 4 A partial schematic diagram of the coolant inlet / outlet and its surrounding area on the front side of anode plate A is shown. The annular protrusion further includes a third annular protrusion 33 and a fourth annular protrusion 34. The third annular protrusion 33 surrounds the coolant inlet 71, and the fourth annular protrusion 34 surrounds the third annular protrusion 33, forming a coolant annular protrusion platform 80 between the third annular protrusion 33 and the fourth annular protrusion 34. In this example, the width of both the third annular protrusion 33 and the fourth annular protrusion 34 is 0.5 mm to 1 mm, and the height is both 2.5 mm to 4 mm. The height of the coolant annular protrusion platform 80 is the same as that of the bridge annular protrusion platform 60.
[0098] Similar to the bridge-shaped annular protrusion platform 60, the coolant annular protrusion platform 80 has a U-shaped groove 61 surrounding a portion of the third annular protrusion 33. The U-shaped groove 61 has a non-closed annular structure, comprising a first end and a second end. On the back of the monopolar plate, coolant passes between the first and second ends of the U-shaped groove 61. The width and depth of the U-shaped groove 61 on the coolant annular protrusion platform 70 are the same as those on the bridge-shaped annular protrusion platform 60.
[0099] Coolant flow guide strip-shaped protrusions 43 are arranged between the coolant inlet and outlet and the third annular protrusion 33. The inner cavities of the coolant flow guide strip-shaped protrusions 43 are used for the passage of coolant. The coolant passes from the coolant inlet, through the inner cavities of the coolant flow guide strip-shaped protrusions 43, the inner cavities of the coolant annular protrusion platforms 80, and into the coolant cavity between the bipolar plates. The coolant can be air or water. In this example, the coolant is water.
[0100] In this example, similar to the bridge annular protrusion platforms 60, the U-shaped grooves 61 on the coolant annular protrusion platforms 80 also have recessed points 62 between the first ends and the second ends of the U-shaped grooves 61, which are used to support the coolant annular protrusion platforms 80. The recessed points 62 are regularly arranged, and the channels between the recessed points 62 on the back of the monopolar plate are used for the passage of coolant, which has a flow guiding effect. The dimensions of the recessed points 62 on the coolant annular protrusion platforms 80 are the same as those of the recessed points 62 on the bridge annular protrusion platforms 60.
[0101] In this example, the outer edge of the fourth annular protrusion 34 is connected to the coolant distribution area 90, and a plurality of outer recessed points 91 are arranged at the connection between the outer edge of the fourth annular protrusion 34 and the coolant distribution area 90, which have a further supporting effect. At the same time, the channels between the outer recessed points 91 are used for the passage of coolant, which has a further flow guiding effect.
[0102] In this example, referring to Figure 5 A sealing ring limiting protrusion 100 is arranged along the circumference of the monopolar plate at a distance from the edge of the monopolar plate. The sealing ring limiting protrusion 100 includes a first sealing ring limiting protrusion 101 and a second sealing ring limiting protrusion 102. The first sealing ring limiting protrusion 101 is arranged at a distance of 0.5mm-2mm from the edge of the monopolar plate. The second sealing ring limiting protrusion 102 is arranged in parallel to the first sealing ring limiting protrusion 101 at a distance of 3.0mm-5mm from the first sealing ring limiting protrusion 101 in the internal region enclosed by the first sealing ring limiting protrusion 101. The first sealing ring limiting protrusion 101 and the second sealing ring limiting protrusion 102 define a polar plate sealing groove 110 therebetween, which is used for the injection or adhesion of a polar plate sealing ring 120. The polar plate sealing ring 120 includes an anode side sealing ring 121 and a cathode side sealing ring 122. In this example, the second sealing ring limiting protrusion 102 is arranged at a distance of ≤0.5mm-1.0mm from the second annular protrusion and the fourth annular protrusion, and at a distance of ≤0.5mm-1.0mm from the edge of the active area of the bipolar plate. The height of the first sealing ring limiting protrusion 101 and the second sealing ring limiting protrusion 102 is the same as the height of the annular protrusion 30. Figure 5Also shown in this example are the gas inlet and outlet sealing rings 130 (including first gas inlet and outlet sealing ring 131 and second gas inlet and outlet sealing ring 132) and the coolant inlet and outlet sealing rings 140. As can be seen, the anode side sealing ring 121 and the cathode side sealing ring 122 are identical, and the gas inlet and outlet sealing rings 130 and the coolant inlet and outlet sealing rings 140 on both monopolar plates are also identical, facilitating the stack assembly of the fuel cell.
[0103] In this example, welding lines or welding points (not shown in the figure) are provided on the back surface of the anode plate A and the back surface of the cathode plate B: welding lines or welding points are provided on the back surface of the bottom of the U-shaped groove 61 and the back surface of the bottom of the recess point 62, respectively; welding lines are provided between the sealing ring limiting protrusion 100 and the outer side strip-shaped protrusion 42 on the back surface of both monopolar plates; and welding lines are provided on the back surface of the bottom of the polar plate sealing groove 110 on the back surface of both monopolar plates. By welding the corresponding welding lines and welding points on the back surface of the anode plate A and the back surface of the cathode plate B, the anode plate A and the cathode plate B are welded to form a bipolar plate.
[0104] In summary, the bridge structure of the bipolar plate of the utility model is composed of the anode plate, the bridge ring-shaped protrusion platform, the strip-shaped protrusion (including the inner side strip-shaped protrusion and the outer side strip-shaped protrusion) and the through hole on the cathode plate, the reaction gas enters the bridge cavity formed by the bridge ring-shaped protrusion platform from the inner cavity of the inner side strip-shaped protrusion of the gas inlet and outlet, then flows into the inner cavity of the outer side strip-shaped protrusion of one monopolar plate, and then flows out through the through hole of the other monopolar plate into the distribution area on the front surface. The bridge ring-shaped protrusion platform is provided with a U-shaped groove, the bottom of which is flush with the reference surface of the bipolar plate, the bottoms of the corresponding U-shaped grooves of the two monopolar plates abut against each other to provide support for the bridge ring-shaped protrusion platform, enhance the structural strength of the bridge area, avoid the collapse of the bridge area under the pressure of the sealing ring and improve the sealing performance of the fuel cell; meanwhile, the platform is provided with recess points, the bottoms of which are also flush with the reference surface of the bipolar plate, which can further provide support, and the channels formed between adjacent recess points extend along the direction of the airflow to guide the airflow. In addition, the coolant ring-shaped protrusion platform on the bipolar plate is also provided with a U-shaped groove and a recess point to enhance the structural strength of itself and further improve the overall structural strength of the bipolar plate.
[0105] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be defined by the appended claims.
Claims
1. A bipolar plate for a fuel cell, characterized by comprising: The bipolar plate comprises an anode plate and a cathode plate, and is provided with a plurality of gas inlets and outlets, annular protrusions, strip-shaped protrusions and through holes. The gas inlets and outlets comprise first gas inlets and outlets and second gas inlets and outlets. The annular protrusions comprise first annular protrusions and second annular protrusions, the first annular protrusions are arranged outside the gas inlets and outlets, and the second annular protrusions are arranged outside the first annular protrusions; a bridge annular protrusion platform is formed between the first annular protrusions and the second annular protrusions, the bridge annular protrusion platform is higher than a reference surface of the bipolar plate and is not higher than the annular protrusions; a U-shaped groove is arranged around the first annular protrusions on the bridge annular protrusion platform, openings are formed between two ends of the U-shaped groove, and the extension direction of the openings is the same as the gas flow direction. The strip-shaped protrusions comprise inner strip-shaped protrusions and outer strip-shaped protrusions; the inner strip-shaped protrusions are arranged between the gas inlets and outlets and the first annular protrusions along the extension direction of the openings; the outer strip-shaped protrusions comprise first outer strip-shaped protrusions and second outer strip-shaped protrusions; the first outer strip-shaped protrusions are arranged at the outer edges of the second annular protrusions outside the first gas inlets and outlets on the cathode plate along the extension direction of the openings; and the second outer strip-shaped protrusions are arranged at the outer edges of the second annular protrusions outside the second gas inlets and outlets on the anode plate along the extension direction of the openings. The through holes comprise anode plate through holes and cathode plate through holes; the anode plate through holes are arranged at the outer edges of the second annular protrusions outside the first gas inlets and outlets on the anode plate along the extension direction of the openings; and the cathode plate through holes are arranged at the outer edges of the second annular protrusions outside the second gas inlets and outlets on the cathode plate along the extension direction of the openings.
2. The bipolar plate for fuel cells as claimed in claim 1, wherein The bottom of the U-shaped groove is flush with the reference surface of the bipolar plate.
3. The bipolar plate for fuel cells as claimed in claim 1, wherein The openings between the two ends of the U-shaped groove are provided with a plurality of recessed points, and channels extending along the gas flow direction are formed between adjacent recessed points.
4. The bipolar plate for fuel cells as claimed in claim 3, wherein The bottom of the recessed point is flush with the reference surface of the bipolar plate.
5. The bipolar plate for fuel cells as claimed in claim 1, wherein The anode plate and the cathode plate are further provided with coolant inlets and outlets; the annular protrusions further comprise third annular protrusions and fourth annular protrusions; The third annular protrusions are arranged outside the coolant inlets and outlets, the fourth annular protrusions are arranged outside the third annular protrusions, and a coolant annular protrusion platform is formed between the third annular protrusions and the fourth annular protrusions; a U-shaped groove is arranged around the third annular protrusions on the coolant annular protrusion platform; Coolant flow guide strip-shaped protrusions are arranged between the coolant inlets and outlets and the third annular protrusions.
6. The bipolar plate for fuel cells as claimed in claim 5, wherein A plurality of recessed points are arranged between the two ends of the U-shaped groove on the coolant annular protrusion platform, and channels extending along the coolant flow direction are formed between adjacent recessed points.
7. The bipolar plate for fuel cells as claimed in claim 5, wherein The bipolar plate comprises a coolant distribution area, the outer edges of the fourth annular protrusions are connected to the coolant distribution area, a plurality of outer recessed points are arranged at the connection between the outer edges of the fourth annular protrusions and the coolant distribution area, and channels extending along the coolant flow direction are formed between adjacent outer recessed points.
8. The bipolar plate for fuel cells as claimed in claim 1, wherein The first annular protrusions and the second annular protrusions have the same width and height.
9. The bipolar plate for fuel cells as claimed in claim 1, wherein The distance between the first annular protrusion and the gas inlet and outlet is 0.5mm-1.5mm.
10. The bipolar plate for fuel cells as claimed in claim 1, wherein The distance between the second annular protrusion and the first annular protrusion is 3mm-5mm.