A composite bipolar plate structure for high performance fuel cells

Abstract

The application relates to the technical field of fuel cell bipolar plates, in particular to a high-performance fuel cell composite bipolar plate structure. The structure comprises two bipolar plates, cooling combination grooves are arranged on the opposite end faces of the two bipolar plates, and the cooling combination grooves on the two bipolar plates form cooling liquid grooves; the cooling combination grooves comprise first and second collecting grooves arranged at the two ends of the bipolar plates, a plurality of strip-shaped grooves are arranged on the bipolar plates between the first and second collecting grooves, the strip-shaped grooves are parallel to each other, the strip-shaped grooves are communicated with the first and second collecting grooves, a side groove is arranged on one side of the bipolar plate, one end of the side groove is communicated with the adjacent strip-shaped groove, and the other end of the side groove is communicated with the first collecting groove; and a flow circulation adjusting piece is slidably arranged in the cooling liquid groove. The flow circulation adjusting piece arranged in a sliding mode can switch the two flow circulation modes of the multi-flow channel direct discharge and the serpentine return of the cooling liquid, the cooling liquid can be quickly discharged in the direct discharge mode, and the direct discharge mode is suitable for low heat load working conditions.

Description

Technical Field

[0001] This invention relates to the field of bipolar plate technology for fuel cells, and more specifically to a composite bipolar plate structure for high-performance fuel cells. Background Technology

[0002] Fuel cell stacks typically consist of multiple fuel cell units stacked in series. The fuel cell unit is mainly composed of two core components: bipolar plates and membrane plates (proton exchange membranes) stacked in series.

[0003] The assembled device is called a bipolar plate. When the bipolar plate is stacked with the membrane electrode assembly (MEA) to form the core of a fuel cell stack, the anode and cathode plates are located between the two proton exchange membranes. Hydrogen and oxygen enter the fuel cell through the hydrogen inlet and oxygen inlet, respectively, to undergo redox reactions, enabling the fuel cell to convert chemical energy into electrical energy through electrochemical reactions. Hydrogen enters the hydrogen flow channel through the hydrogen inlet to provide hydrogen for the electrochemical reaction, and oxygen enters the oxygen flow channel through the oxygen inlet to provide oxygen for the electrochemical reaction.

[0004] During the power generation process of a fuel cell, coolant is introduced between the anode and cathode plates to remove the heat generated by the electrochemical reaction and maintain the battery at a suitable temperature.

[0005] Currently, the flow channel shape of most bipolar plates is usually determined during the manufacturing process. Different flow channels serve different purposes; for example, multiple parallel flow channels and serpentine flow channels have different characteristics. However, different high-performance, high-power fuel cells require different flow channel patterns for bipolar plates in different application scenarios. Therefore, metal bipolar plates with unchangeable flow channel patterns cannot adapt to fuel cells in different application scenarios, resulting in poor adaptability.

[0006] The characteristics of a serpentine flow channel: A serpentine flow channel has a longer channel length and multiple bends, which helps increase the residence time of the fluid in the channel, improving the heat exchange efficiency between the coolant and the channel wall, resulting in better heat dissipation than multiple parallel flow channels. However, to achieve the same coolant flow velocity in a serpentine flow channel as in a multiple parallel flow channel, the pump power required for the serpentine flow channel is much greater. This is because the serpentine flow channel has a higher resistance base and a longer length; even to achieve a very low coolant flow velocity, a large pump power is required. Furthermore, the coolant flows unidirectionally from inlet to outlet, being heated sequentially throughout, resulting in a significant temperature gradient in the fuel cell stack along the flow channel direction.

[0007] The characteristics of multiple parallel flow channels are: short flow path, low resistance, low required pump power, small temperature difference between inlet and outlet, and relatively gentle temperature distribution of the fuel cell stack along the flow channel direction. However, because the coolant has a short path from inlet to outlet in the parallel flow channel, the liquid flows away before it has been heated much, resulting in low heat exchange efficiency between the coolant and the flow channel wall, thus limiting heat dissipation capacity.

[0008] Both serpentine flow channels and multiple parallel flow channels have their own advantages and disadvantages. Therefore, if a bipolar plate adopts only a single flow channel design, it will inevitably have corresponding drawbacks. Thus, it would be highly advantageous if the bipolar plate could change its flow channel design according to different application scenarios. Summary of the Invention

[0009] The main objective of this invention is to provide a composite bipolar plate structure for a high-performance fuel cell that can adjust the cooling mode as needed.

[0010] To achieve the above objectives, the technical solution provided by this invention is as follows: A composite bipolar plate structure for a high-performance fuel cell includes two plates. Hydrogen and oxygen channels are respectively provided on opposite sides of the two plates. Cooling combination grooves are formed on the opposite end faces of both plates, symmetrically arranged to form a coolant reservoir. Each cooling combination groove includes a first and a second channel located at both ends of the plates. Multiple parallel strip grooves are formed on the plate between the first and second channels, connecting the first and second channels. A side groove is provided on one side of the electrode plate. One end of the side groove is connected to an adjacent strip groove, and the other end of the side groove is connected to the first collection groove. A flow regulating component is slidably arranged in the coolant tank. After entering the first collection groove, the coolant enters the second collection groove through multiple flow channels formed between the flow regulating component and the coolant tank. After entering the second collection groove, the flow regulating component slides towards the first collection groove in the coolant tank. The coolant flows through the serpentine channel formed between the flow regulating component and the coolant tank and then enters the first collection groove from the side groove. The two electrode plates are the anode plate and the cathode plate, respectively.

[0011] Specifically, the anode plate and cathode plate are located between two proton exchange membranes. A hydrogen flow channel is provided on the side of the anode plate away from the cathode plate. A hydrogen inlet is provided at one end of the anode plate and the cathode plate, and a hydrogen outlet is provided at the other end of the anode plate and the cathode plate. The hydrogen flow channel is connected to the hydrogen inlet and the hydrogen outlet, and the hydrogen flow channel, the hydrogen inlet, and the hydrogen outlet constitute a hydrogen channel. An oxygen flow channel is provided on the side of the cathode plate away from the anode plate. An oxygen inlet is provided at one end of the anode plate and the cathode plate, and an oxygen outlet is provided at the other end of the anode plate and the cathode plate. The oxygen flow channel is connected to the oxygen inlet and the oxygen outlet, and the oxygen flow channel, the oxygen inlet, and the oxygen outlet constitute an oxygen channel.

[0012] Specifically, a first liquid port is provided at one end of the anode plate and the cathode plate, and the first liquid port is connected to the first collection tank. A second liquid port is provided at the other end of the anode plate and the cathode plate, and the second liquid port is connected to the second collection tank.

[0013] Specifically, the flow regulating component includes a sliding plate slidably disposed between the second conduits, a strip plate slidably disposed between two symmetrical strip grooves, the strip plate being fixedly connected to the sliding plate, the thickness of the sliding plate being less than the thickness of the strip plate, and the strip plate dividing the strip groove in which it is located into two flow grooves; a second turning groove is formed on the side of the strip plate facing the first conduit, and the second turning groove communicates with the two flow grooves in the strip groove; a first turning groove is formed on the side of the electrode plate portion between two adjacent strip grooves near the second conduit, and the first turning groove communicates with the two adjacent flow grooves in the two adjacent strip grooves.

[0014] Specifically, the strip plate has two third inclined surfaces processed at the end facing the first conduit, forming a conical end at that end. A first inclined surface parallel to the third inclined surface is processed on the electrode plate. After the strip plate moves towards the first conduit, the third inclined surface contacts the corresponding first inclined surface, blocking the first conduit and the flow channel. A wedge is fixed on the strip plate inside the second conduit. One wedge is fixed on the strip plate away from the side channel, and one wedge on the strip plate away from the side channel is close to the center of the electrode plate. Two wedges are fixed on the other strip plates, corresponding to the flow channels. A second inclined surface corresponding to the inclined surface of the wedge is opened on the electrode plate. After the strip plate and sliding plate move towards the first conduit, the inclined surface of the wedge contacts the corresponding second inclined surface, and the flow channel corresponding to the wedge is no longer connected to the second conduit. One flow channel away from the side channel remains connected to the second conduit. Multiple flow channels, multiple first turning channels, and multiple second turning channels form a serpentine channel, which is connected to the side channel.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By using a sliding flow regulator, the coolant can be switched between two flow modes: direct flow and serpentine recirculation. In direct flow mode, the coolant flows quickly, which is suitable for low heat load conditions. In serpentine mode, the coolant flows repeatedly in a meandering manner, extending the heat exchange path and enhancing heat dissipation efficiency, which is suitable for high heat load conditions, enabling the fuel cell to flexibly cope with different operating environments.

[0016] 2. The cooling combination tank adopts a hierarchical structure of confluence channels, strip channels and turning channels, combined with the mechanical linkage of wedges and inclined planes, to precisely control the flow path and flow rate distribution of the coolant, avoid local overheating or uneven cooling, improve the overall heat dissipation efficiency of the electrode plates, and extend the service life of the fuel cell.

[0017] 3. It supports bidirectional inlet of coolant from either the first or second inlet. The inlet direction can be flexibly selected according to the layout of the fuel cell stack and the pressure characteristics of the external cooling system, adapting to diverse system integration solutions and reducing system modification costs.

[0018] 4. It does not rely on electronic control or complex sensors to change the flow pattern of coolant, and has a simple structure and low failure rate.

[0019] 5. The strip grooves, steering grooves and wedges are integrated inside the electrode plate, without occupying additional external space of the fuel cell stack. While achieving multi-mode cooling, the electrode plate remains thin and light, which is conducive to the compact integration and lightweight design of the fuel cell system. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the composite bipolar plate.

[0021] Figure 2 This is a schematic diagram of the oxygen flow path on the cathode plate.

[0022] Figure 3 This is a schematic diagram of the separate structure of the anode plate, cathode plate, and flow regulating component.

[0023] Figure 4 This is a schematic diagram showing the distribution of the wedges on the strip plate.

[0024] Figure 5 This is a schematic diagram of a strip plate located inside a groove.

[0025] Figure 6 This is a schematic diagram of the cooling assembly tank on the cathode plate.

[0026] Figure 7 This is a schematic diagram of a flow regulating component.

[0027] Figure 8 This is a schematic diagram showing the flow state of the coolant after it enters the first manifold.

[0028] Figure 9 This is a schematic diagram showing the flow state of the coolant after it enters the second manifold.

[0029] The components in the attached diagram are named as follows: 1. Anode plate; 2. Cathode plate; 3. Hydrogen inlet; 4. Hydrogen flow channel; 5. Hydrogen outlet; 6. Oxygen inlet; 7. Oxygen flow channel; 8. Oxygen outlet; 9. First liquid inlet; 10. Second liquid inlet; 11. Strip groove; 111. First confluence groove; 112. Second confluence groove; 12. First turning groove; 13. First inclined surface; 14. Second inclined surface; 15. Sliding plate; 16. Strip plate; 17. Second turning groove; 18. Third inclined surface; 19. Wedge block; 20. Side groove. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] like Figures 1-9 As shown, a composite bipolar plate structure for a high-performance fuel cell includes two plates, with hydrogen and oxygen channels respectively provided on opposite sides of the two plates. The two plates are an anode plate 1 and a cathode plate 2.

[0032] Anode plate 1 and cathode plate 2 are located between two proton exchange membranes.

[0033] A hydrogen flow channel 4 is provided on the side of the anode plate 1 away from the cathode plate 2. A hydrogen inlet 3 is provided at one end of the anode plate 1 and the cathode plate 2, and a hydrogen outlet 5 is provided at the other end of the anode plate 1 and the cathode plate 2. The hydrogen flow channel 4 is connected to the hydrogen inlet 3 and the hydrogen outlet 5. The hydrogen flow channel 4, the hydrogen inlet 3 and the hydrogen outlet 5 constitute a hydrogen channel.

[0034] An oxygen flow channel 7 is provided on the side of the cathode plate 2 away from the anode plate 1. An oxygen inlet 6 is provided at one end of the anode plate 1 and the cathode plate 2, and an oxygen outlet 8 is provided at the other end of the anode plate 1 and the cathode plate 2. The oxygen flow channel 7 is connected to the oxygen inlet 6 and the oxygen outlet 8, and the oxygen flow channel 7, the oxygen inlet 6 and the oxygen outlet 8 constitute an oxygen channel.

[0035] Cooling combination grooves are provided on the opposite end faces of the two electrode plates. The cooling combination grooves on the two electrode plates are symmetrically arranged and form a coolant tank.

[0036] The cooling assembly tank includes a first collection channel 111 and a second collection channel 112 opened at both ends of the electrode plate. A first liquid port 9 is opened at one end of the anode plate 1 and the cathode plate 2, and the first liquid port 9 is connected to the first collection channel 111. A second liquid port 10 is opened at the other end of the anode plate 1 and the cathode plate 2, and the second liquid port 10 is connected to the second collection channel 112.

[0037] Multiple strip grooves 11 are formed on the electrode plate between the first channel 111 and the second channel 112. The multiple strip grooves 11 are parallel to each other and connect the first channel 111 and the second channel 112. A side groove 20 is formed on one side of the electrode plate. One end of the side groove 20 is connected to the adjacent strip groove 11, and the other end of the side groove 20 is connected to the first channel 111.

[0038] A flow regulating component is slidably installed inside the coolant tank.

[0039] After entering from the first manifold 111, the coolant enters the second manifold 112 through multiple flow channels formed between the flow regulating component and the coolant tank.

[0040] After the coolant enters from the second manifold 112, the flow regulating component slides in the coolant tank towards the first manifold 111. After the coolant flows through the serpentine channel formed between the flow regulating component and the coolant tank, it enters the first manifold 111 from the side channel 20. Specifically, the flow regulating component includes a sliding plate 15 slidably disposed between the second channel 112, and a strip plate 16 slidably disposed between two symmetrical strip channels 11. The strip plate 16 is fixedly connected to the sliding plate 15. The thickness of the sliding plate 15 is less than the thickness of the strip plate 16. The strip plate 16 divides the strip channel 11 in which it is located into two flow channels.

[0041] A second turning groove 17 is provided on the side of the strip plate 16 facing the first conduit 111. The second turning groove 17 is connected to two flow grooves in the strip groove 11.

[0042] A first turning groove 12 is provided on the side of the electrode plate portion between two adjacent strip grooves 11 near the second conduit 112. The first turning groove 12 connects two adjacent flow grooves in the two adjacent strip grooves 11.

[0043] Two third inclined surfaces 18 are machined on the end of the strip plate 16 facing the first channel 111, so that the end of the strip plate 16 facing the first channel 111 forms a conical end.

[0044] The electrode plate is processed with a first inclined surface 13 parallel to the third inclined surface 18. After the strip plate 16 moves toward the first channel 111, the third inclined surface 18 contacts the opposite first inclined surface 13 and blocks the first channel 111 and the flow channel.

[0045] A wedge 19 is fixed on the strip plate 16 inside the second channel 112. One wedge 19 is fixed on the strip plate 16 away from the side channel 20. The wedge 19 on the strip plate 16 away from the side channel 20 is close to the center of the electrode plate. Two wedges 19 are fixed on the other strip plates 16. The wedge 19 corresponds to the flow channel. A second inclined surface 14 corresponding to the inclined surface of the wedge 19 is opened on the electrode plate. After the strip plate 16 and the sliding plate 15 move towards the first channel 111, the inclined surface of the wedge 19 contacts the corresponding second inclined surface 14. The flow channel corresponding to the wedge 19 is not connected to the second channel 112. One flow channel away from the side channel 20 is connected to the second channel 112. Multiple flow channels, multiple first turning channels 12 and multiple second turning channels 17 form a serpentine channel. The serpentine channel is connected to the side channel 20.

[0046] like Figures 3-7As shown, in this embodiment, five strip grooves 11 and five strip plates 16 are provided. For ease of description, the five strip grooves 11 are, from left to right, the first groove, the second groove, the third groove, the fourth groove, and the fifth groove. The strip plates 16 are, from left to right, the first plate, the second plate, the third plate, the fourth plate, and the fifth plate. A wedge block 19 is provided on the first plate, and the wedge block 19 on the right side of the first plate. A wedge block 19 is provided on both the left and right sides of the second, third, fourth, and fifth plates. The first plate divides the first groove into two flow grooves, the second plate divides the second groove into two flow grooves, the third plate divides the third groove into two flow grooves, the fourth plate divides the fourth groove into two flow grooves, and the fifth plate divides the fifth groove into two flow grooves.

[0047] There are four first steering grooves 12, which are the first guide groove, the second guide groove, the third guide groove and the fourth guide groove from left to right.

[0048] like Figure 8 As shown, after the coolant enters the first manifold 111 from the first liquid port 9, the coolant in the first manifold 111 can flow through the two flow channels in the strip groove 11 and then enter the second manifold 112 and be discharged from the second liquid port 10.

[0049] Simultaneously, the coolant in the first conduit 111 enters from one end of the side channel 20 and then from the other end of the side channel 20 into the flow channel on the right side of the fifth channel. At this time, the coolant flows in a multi-channel manner between the two plates.

[0050] like Figure 9As shown, after the coolant enters the second manifold 112 from the second inlet 10, under the pressure of the coolant, the flow regulating component can move towards the first manifold 111. The sliding plate 15 slides in the second manifold 112, and the strip plate 16 slides in the strip groove 11. When the inclined surface of the wedge block 19 contacts the second inclined surface 14, the opposing first inclined surface 13 contacts the third inclined surface 18. At this time, two flow channels in the first, second, third, fourth, and fifth manifolds are not connected to the first manifold 111, the flow channel on the right side of the first manifold is not connected to the second manifold 112, the flow channels in the second, third, fourth, and fifth manifolds are not connected to the second manifold 112, one end of the flow channel on the left side of the first manifold remains connected to the second manifold 112, and the flow channel on the right side of the fifth manifold is connected to the side groove 20. Therefore, the coolant entering the second manifold 112 flows sequentially through the flow channel on the left side of the first manifold, the second turning channel 17 on the first plate, the flow channel on the right side of the first manifold, the first guide channel, the flow channel on the left side of the second manifold, the second turning channel 17 on the second plate, the flow channel on the right side of the second manifold, the second guide channel, the flow channel on the left side of the third manifold, the second turning channel 17 on the third plate, the flow channel on the right side of the third manifold, the third guide channel, the flow channel on the left side of the fourth manifold, the second turning channel 17 on the fourth plate, the flow channel on the right side of the fourth manifold, the fourth guide channel, the flow channel on the left side of the fifth manifold, the second turning channel 17 on the fifth plate, the flow channel on the right side of the fifth manifold, and the side channel 20 before entering the first manifold 111 and exiting from the first liquid outlet 9. At this time, the coolant flows in a serpentine pattern in the coolant tank between the two plates.

[0051] This technical solution can change the direction of coolant inlet, thereby changing the flow pattern of coolant between the two plates, making the fuel cell suitable for different operating conditions.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite bipolar plate structure for a high-performance fuel cell, comprising two plates, wherein a hydrogen channel and an oxygen channel are respectively provided on opposite sides of the two plates, characterized in that, Cooling combination grooves are provided on the opposite end faces of the two electrode plates. The cooling combination grooves on the two electrode plates are symmetrically arranged and form a coolant tank. The cooling combination groove includes a first conduit (111) and a second conduit (112) opened at both ends of the electrode plates. Multiple strip grooves (11) are opened on the electrode plate between the first conduit (111) and the second conduit (112). The multiple strip grooves (11) are parallel to each other and connect the first conduit (111) and the second conduit (112). A side groove (20) is opened on one side of the electrode plate. One end of the side groove (20) is connected to the adjacent strip groove (11), and the other end of the side groove (20) is connected to the first conduit (111). A flow regulating element is slidably arranged in the coolant tank. After the coolant enters from the first conduit (111), it enters the second conduit (112) through multiple flow channels formed between the flow regulating element and the coolant tank. After the coolant enters from the second manifold (112), the flow regulating component slides in the coolant tank towards the first manifold (111). After the coolant flows through the serpentine channel formed between the flow regulating component and the coolant tank, it enters the first manifold (111) from the side groove (20). The two plates are the anode plate (1) and the cathode plate (2).

2. The composite bipolar plate structure of a high-performance fuel cell according to claim 1, characterized in that, The anode plate (1) and cathode plate (2) are located between two proton exchange membranes. A hydrogen flow channel (4) is provided on the side of the anode plate (1) away from the cathode plate (2). A hydrogen inlet (3) is provided at one end of the anode plate (1) and cathode plate (2), and a hydrogen outlet (5) is provided at the other end of the anode plate (1) and cathode plate (2). The hydrogen flow channel (4) is connected to the hydrogen inlet (3) and hydrogen outlet (5). The hydrogen flow channel (4), hydrogen inlet (3) and hydrogen outlet (5) constitute a hydrogen channel. An oxygen flow channel (7) is provided on the side of the cathode plate (2) away from the anode plate (1). An oxygen inlet (6) is provided at one end of the anode plate (1) and cathode plate (2), and an oxygen outlet (8) is provided at the other end of the anode plate (1) and cathode plate (2). The oxygen flow channel (7) is connected to the oxygen inlet (6) and oxygen outlet (8). The oxygen flow channel (7), oxygen inlet (6) and oxygen outlet (8) constitute an oxygen channel.

3. The composite bipolar plate structure of a high-performance fuel cell according to claim 1, characterized in that, The anode plate (1) and cathode plate (2) are provided with a first liquid port (9) at one end, which is connected to the first collection channel (111). The anode plate (1) and cathode plate (2) are provided with a second liquid port (10) at the other end, which is connected to the second collection channel (112).

4. The composite bipolar plate structure of a high-performance fuel cell according to claim 1, characterized in that, The flow regulating component includes a sliding plate (15) slidably disposed between the second conduit (112), a strip plate (16) slidably disposed between two symmetrical strip grooves (11), the strip plate (16) being fixedly connected to the sliding plate (15), the thickness of the sliding plate (15) being less than the thickness of the strip plate (16), the strip plate (16) dividing the strip groove (11) it is located into two flow grooves; a second turning groove (17) is provided on the side of the strip plate (16) facing the first conduit (111), the second turning groove (17) communicating with the two flow grooves in the strip groove (11); a first turning groove (12) is provided on the side of the electrode plate portion between two adjacent strip grooves (11) near the second conduit (112), the first turning groove (12) communicating with the two adjacent flow grooves in the two adjacent strip grooves (11).

5. The composite bipolar plate structure of a high-performance fuel cell according to claim 4, characterized in that, The strip plate (16) has two third inclined surfaces (18) machined at one end facing the first channel (111), forming a conical end at the end of the strip plate (16) facing the first channel (111); a first inclined surface (13) parallel to the third inclined surface (18) is machined on the electrode plate. After the strip plate (16) moves towards the first channel (111), the third inclined surface (18) contacts the opposite first inclined surface (13) and blocks the first channel (111) and the flow channel; a wedge (19) is fixed on the strip plate (16) in the second channel (112), and a wedge (19) is fixed on the strip plate (16) away from the side channel (20), and a wedge (19) is fixed on the strip plate (16) away from the side channel (20). 9) Near the center of the electrode plate, two wedges (19) are fixed on the other strip plates (16). The wedges (19) correspond to the flow grooves. The electrode plate has a second inclined surface (14) corresponding to the inclined surface of the wedges (19). After the strip plates (16) and the sliding plate (15) move towards the first conduit (111), the inclined surface of the wedges (19) contacts the corresponding second inclined surface (14). The flow groove corresponding to the wedges (19) is not connected to the second conduit (112). A flow groove away from the side groove (20) is connected to the second conduit (112). Multiple flow grooves, multiple first turning grooves (12) and multiple second turning grooves (17) form a serpentine channel. The serpentine channel is connected to the side groove (20).

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