Parallel sealing device and sealing method for bipolar plates of fuel cell

Abstract

The invention discloses a fuel cell bipolar plate parallel sealing device and a sealing method. The sealing device comprises a first bipolar plate and a second bipolar plate, a plurality of groups of supporting cushion blocks are embedded into the insulating sealing gasket to form a sealing frame; the sealing method comprises the steps that a supporting cushion block penetrates through and is embedded into an insulating sealing gasket to form a sealing frame; the first bipolar plate and the one or more second bipolar plates are aligned and stacked through the insulating sealing gasket to form a multi-layer stacked structure; and a plurality of groups of adjacent multi-layer stacked structures are stacked and assembled with the membrane electrodes to form a multi-stack fuel cell. According to the invention, while the power density of the stack is improved, the stack sealing performance of the bipolar plate of the stack, the uniformity of large-stack press-fitting force and the electrical insulation isolation performance among the single cells are improved, the vibration resistance and the impact resistance of the stack are effectively improved, and a relatively concentrated fluid header pipe port is designed, so that the local flow resistance of fluid can be reduced, and the reliability of the stack is improved. The processing difficulty and the manufacturing cost of auxiliary parts are reduced, the interchangeability of the assembled battery is improved, and the later maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell bipolar plate parallel sealing device and a sealing method. Background Art

[0002] A fuel cell is an electrochemical energy conversion device that can convert the chemical energy in fuel into electrical energy through electrochemical reactions inside the stack during energy conversion. During the development and integrated design research of high-power fuel cell engines for commercial heavy trucks, the peripheral size of the stack is large and the power density is low. Therefore, it cannot meet the installation in the limited space under the vehicle cockpit of the fuel cell engine system. During the design layout process, the boundary of the stack components is likely to exceed the available range of the vehicle. As the bipolar plate and membrane electrode are the core components inside the stack, how to design the integrated arrangement layout scheme of the bipolar plate is the direct path to maximize the power density of the stack.

[0003] In the existing fuel cell packaging structures: one is to maintain the packaging force of the stack through tie rods or tie plates. Sealing is achieved by laying sealing glue lines or dispensing glue inside the sealing grooves on both sides of the bipolar plate. Since it involves the fixation of the stack inside the packaging box and fluid transfer, the internal module integration structure of the stack is complex. To meet the packaging force requirements for vehicle vibration and shock, a large amount of internal fixation and maintenance replacement space is required inside the stack. Moreover, the fluid parallel connection and electrical series connection schemes for multiple stacks are all based on the packaging of tie rods or tie plates inside the packaging box to achieve the integration of high-power stack systems. The three-chamber pressure tolerance of the stack is low, the space layout is large, and the sealing performance is poor. When the packaging shell of the stack is used to maintain the pressing force and sealing performance between the stack and the membrane electrode, the inside of the bipolar plate still uses laid sealing glue lines and dispensing glue to achieve the sealing performance. By using a frame-type PACK to press the stack, due to the limitations of the stack pressing process, after the independent stack PACKs are pressed, the combined assembly of each stack is carried out. The flange fixation and sealing between PACKs require a large amount of space and operating steps, resulting in a low overall power density of the stack. Summary of the Invention

[0004] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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 of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0005] The purpose of the present invention is to solve the deficiencies in the prior art and propose a fuel cell bipolar plate parallel sealing device and a sealing method.

[0006] To achieve the above object, in a first aspect, the present invention provides a fuel cell bipolar plate parallel sealing device, comprising: a first bipolar plate and a second bipolar plate; The first bipolar plate and one or more of the second bipolar plates are aligned and stacked through an insulating gasket wrapped on the outside to form a multi-layer stacked structure; A plurality of support pads are embedded inside the insulating gasket to form a sealing frame, and the support pads are used for limiting and supporting.

[0007] In some embodiments, between adjacent multi-group multi-layer stacked structures, a multi-stack fuel cell is formed by vertically and / or horizontally stacking and assembling with a membrane electrode assembly.

[0008] In some embodiments, a plurality of groups of mounting holes are symmetrically formed at the edge of the insulating gasket, and the support pads are penetrated and embedded in the mounting holes.

[0009] In some embodiments, positioning holes are formed at the diagonal corners of the insulating gasket, and the positioning holes include a first inner positioning hole and a second inner positioning hole.

[0010] In some embodiments, the support pads are symmetrically embedded at the edge of the insulating gasket.

[0011] In some embodiments, 8-16 groups of support pads are symmetrically arranged, and the cross section of the support pads is rectangular, L-shaped, triangular or arc-shaped.

[0012] In some embodiments, a flow field region is provided in the middle of the first bipolar plate and the second bipolar plate, and an inlet distribution region and an outlet distribution region are symmetrically provided on both sides of the flow field region.

[0013] In some embodiments, a first three-chamber nozzle is provided outside the inlet distribution region, and the three-chamber nozzle includes a hydrogen inlet hole, a water inlet and an air exhaust hole. A second three-chamber nozzle is provided outside the outlet distribution region, and the three-chamber nozzle includes an air inlet hole, a water outlet and a hydrogen exhaust hole.

[0014] In a second aspect, the present invention further provides a fuel cell bipolar plate parallel sealing method for sealing the fuel cell bipolar plate parallel sealing device described in the first aspect. The sealing method includes: S100, a plurality of support pads are penetrated and embedded inside the insulating gasket to form a sealing frame; S200, the first bipolar plate and one or more second bipolar plates are aligned and stacked through an insulating gasket wrapped on the outside to form a multi-layer stacked structure; S300, between adjacent multi-group multi-layer stacked structures, a multi-stack fuel cell is formed by vertically and / or horizontally stacking and assembling with a membrane electrode assembly.

[0015] In some of these embodiments, the S300 includes: S310, selecting a vertical and / or tiled stacking scheme according to the layout space, and calculating the number of multi-axis stacking groups; S320, the multi-layer stacking structure positions the assembly accuracy through the first inner positioning hole and the second inner positioning hole, and presses the membrane electrode between adjacent multi-layer stacking structures to form a parallel multi-stack fuel cell.

[0016] The present invention has the following beneficial effects: 1. In the present invention, the first bipolar plate and one or more second bipolar plates are aligned and stacked through an insulating gasket wrapped on the outside to form a multi-layer stacking structure; through the stacking and combined arrangement of the plate sealing structure, the sealing problem of multi-stack parallel connection can be effectively solved; 2. In the present invention, multiple groups of support pads made of metal are embedded inside the insulating gasket made of rubber, and a sealing frame is formed through independent plastic sealing and cementing. While improving the power density of the stack, it improves the stacking sealing performance of the bipolar plates of the stack, the uniformity of the large-stack pressing force, and the electrical insulation isolation between single cells, and can effectively improve the anti-vibration and anti-impact performance of the stack. Designing a relatively concentrated fluid manifold port can further reduce the local flow resistance of the fluid, while reducing the processing difficulty and manufacturing cost of related auxiliary components such as distribution manifolds; and can effectively improve the interchangeability of the combined battery, improve the application reliability, reduce the later maintenance and replacement costs, and achieve low-value control throughout the life cycle.

[0017] 3. In the present invention, adjacent multi-group multi-layer stacking structures are assembled with membrane electrodes through vertical and / or tiled stacking to form a multi-stack fuel cell. Through the parallel sealing structure, high-efficiency sealing and production of the bipolar plates are realized, effectively improving the processing efficiency of the battery and reducing the control cost in the large-scale production process. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of a fuel cell bipolar plate parallel sealing device proposed by the present invention; Figure 2 is a schematic flow chart of a fuel cell bipolar plate parallel sealing method proposed by the present invention Figure 1 ; Figure 3 is a schematic flow chart of a fuel cell bipolar plate parallel sealing method proposed by the present invention Figure 2 .

[0019] Legend Explanation: 1. First bipolar plate; 2. Second bipolar plate; 3. Insulating gasket; 31. Mounting hole; 32. Positioning hole; 321. First inner positioning hole; 322. Second inner positioning hole; 4. Support pad; 5. Flow field area; 6. Inlet distribution area; 7. Outlet distribution area; 8. First triple-chamber pipe orifice; 81. Hydrogen inlet hole; 82. Water inlet; 83. Air exhaust hole; 9. Second triple-chamber pipe orifice; 91. Air inlet hole; 92. Water outlet; 93. Hydrogen exhaust hole. Detailed implementation manners

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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.

[0021] The embodiments of the present application provide a fuel cell bipolar plate parallel sealing device and a sealing method, which solve the problems in the prior art that the sealing and insulation of stack parallel connection are poor, the triple-chamber pressure tolerance is low, and the encapsulation force cannot be maintained. Through the stacking and combined arrangement of the plate sealing structure, the sealing problem of multi-stack parallel connection can be effectively solved; by forming a sealing frame through the method of independent plastic encapsulation and cementing, while improving the power density of the stack, the stacking sealing performance of the bipolar plates of the stack, the uniformity of the large stack pressing force, and the electrical insulation isolation between single cells are improved. Moreover, when designing a relatively concentrated fluid main pipe orifice, the local flow resistance of the fluid can be further reduced, and at the same time, the processing difficulty and manufacturing cost of related auxiliary components such as distribution manifolds are reduced; through the parallel sealing structure, the high-efficiency sealing and production of the plates are realized, the processing efficiency of the battery is effectively improved, and the control cost in the large-scale production process is reduced.

[0022] Specifically, please refer to the following embodiments: Referring to Figure 1 , an embodiment of a fuel cell bipolar plate parallel sealing device provided by the present invention, the specific structure includes: a first bipolar plate 1 and a second bipolar plate 2. Among them, the first bipolar plate 1 can be aligned and stacked with one or more second bipolar plates 2 through the insulating gasket 3 wrapped on the outside, so as to form a multi-layer stacked structure.

[0023] It can be understood that the first bipolar plate 1 and one or more second bipolar plates 2 are aligned and stacked through the insulating gasket 3 wrapped on the outside to form a multi-layer stacked structure. Based on the requirements of the overall performance and space layout of the stack, through this stacking method, the power of the stack can be increased in a limited space. At the same time, the insulating property of the insulating gasket 3 can effectively solve the sealing problem of multi-stack parallel connection, avoid problems such as short circuit caused by current conduction between different plates, and ensure the safe and stable operation of the stack.

[0024] Specifically, it should be noted that multiple groups of support pads 4 are embedded inside the insulating gasket 3 to form a sealing frame: multiple groups of mounting holes 31 are symmetrically formed at the edge of the insulating gasket 3, and the support pads 4 are inserted through the mounting holes 31, which can better meet the requirements of the fuel cell stack under different working conditions, effectively improving the sealing and electrical insulation performance; moreover, neither the vibration generated during vehicle driving nor the impact under some special working conditions can cause great influence on the interior of the fuel cell stack, ensuring the long-term stable operation of the fuel cell stack and extending its service life.

[0025] In addition, due to the adoption of standardized structure and component design, damaged components can be conveniently replaced during later maintenance and replacement processes, improving the maintenance efficiency of the entire fuel cell stack system; at the same time, the high interchangeability also enhances the reliability of fuel cell stack applications and reduces the operation risks brought by improper maintenance or mismatched component replacement in the later stage.

[0026] Specifically, the support pads 4 are symmetrically arranged at the edge of the insulating gasket 3, and the number of support pads 4 is symmetrically set to 8 - 16 groups, and its cross-sectional shape can be rectangular, L-shaped, multi-stack fuel cell-shaped, triangular or arc-shaped.

[0027] It can be understood that multiple groups of support pads 4 made of metal are embedded inside the insulating gasket 3 made of rubber to form a sealing frame through independent plastic encapsulation and bonding. During the operation of the fuel cell stack, due to factors such as electrochemical reactions inside the fuel cell stack and external vibrations, the bipolar plates will be subjected to forces in different directions, and the support pads 4 can play a role in limiting and fixing support in the positive and negative directions of the X-axis and the positive and negative directions of the Y-axis of the multi-stack fuel cell, thereby maintaining the pressing force between the first bipolar plate 1 and the second bipolar plate 2 and the sealing gasket, and preventing the displacement of the bipolar plates during operation.

[0028] Specifically, the insulating gasket 3 connecting the common areas of the edges of the first bipolar plate 1 and the second bipolar plate 2 is made of insulating materials such as rubber (for example, food-grade silicone rubber or fluororubber as the gasket). It naturally has good elasticity and insulation. While solving the electrical insulation problem between the upper and lower bipolar plates, it can effectively improve the vibration and shock resistance of the bipolar plate, thereby extending the service life of the bipolar plate. Correspondingly, the support pad 4 is made of alloy (for example, metal materials such as aluminum alloy as the embedded part). The support pads 4 with specific cross-sectional shapes are arranged in the positive and negative directions of the X-axis and Y-axis of the multi-stack fuel cell to provide support for the bipolar plate from multiple directions while reducing the weight, further enhancing the vibration and shock resistance. When the bipolar plate assembly is press-fitted, the through embedded support pad 4 can also be used as the inner and outer peripheral pull plates of the stack to provide the encapsulation force for the pressing of the stack, ensuring the tight combination of the components inside the stack, and thus improving the overall performance of the stack.

[0029] It can be understood that in the positive and negative directions of the Z-axis, in the way of matching a group of bipolar plates with a group of membrane electrodes of the same type, the stacking in the Z-axis direction of the multi-stack fuel cell is realized. To ensure the centering of the bipolar plate assembly during the stacking process in the Z-axis direction of the multi-stack fuel cell, positioning holes 32 for positioning are designed on the diagonal of the insulating gasket 3 along the X-axis direction of the multi-stack fuel cell formed by the bipolar plates.

[0030] Specifically, the shapes of the first inner positioning hole 321 and the second inner positioning hole 322 are different (exemplarily, as Figure 1 shown, the shape of the first inner positioning hole 321 can be circular, while the shape of the second inner positioning hole 322 can be key-shaped).

[0031] It can be understood that the first inner positioning hole 321 serves as the key positioning point to ensure the accurate position of the bipolar plate in the positive and negative directions of the X-axis of the multi-stack fuel cell during the entire stacking process; the second inner positioning hole 322 serves as the positioning point in the positive and negative directions of the Y-axis of the multi-stack fuel cell, releasing the positioning in the positive and negative directions of the X-axis of the multi-stack fuel cell to avoid affecting the assembly efficiency due to repeated positioning. This positioning method can effectively ensure the position accuracy of each bipolar plate during the stacking process, improving the stacking accuracy and efficiency.

[0032] Furthermore, a flow field area 5 is arranged in the middle of the first bipolar plate 1 and the second bipolar plate 2, and an inlet distribution area 6 and an outlet distribution area 7 are symmetrically arranged on both sides of the flow field area 5, which are respectively responsible for the connection of the reaction gas and the discharge of the product; correspondingly, a first three-cavity pipe opening 8 is arranged on the outside of the inlet distribution area 6, and the three-cavity pipe opening includes a hydrogen inlet hole 81, a water inlet 82 and an air exhaust hole 83; a second three-cavity pipe opening 9 is correspondingly arranged on the outside of the outlet distribution area 7, and the three-cavity pipe opening includes an air inlet hole 91, a water outlet 92 and a hydrogen exhaust hole 93, thereby ensuring that the reaction gas and fluid can accurately enter and flow out of the electrode plate to maintain the normal operation of the fuel cell stack.

[0033] It should be explained in detail that multiple stacks of fuel cells are formed by vertical and / or flat stacking and membrane electrode assembly between adjacent groups of multi-layer stacking structures. This high-efficiency sealing and production method of the plate is achieved through a parallel sealing structure, which effectively improves the processing efficiency of the battery and reduces the management and control costs in the large-scale production process. In the vertical or flat stacking process, each multi-layer stacking structure cooperates with each other. Through the joint action of the insulating sealing pad 3 and the supporting pad 4, the insulation of the non-metallic parts can be fully utilized for electrical isolation, and the strong supporting strength of the metal support frame is used as a pull rod or a pull plate to provide a compression packaging force for the stack, which effectively reduces the number of components of the stack combination, and can effectively improve the space utilization of the multi-stack combination inside the stack, and finally make the engine system more efficient and more power dense in a limited space, so as to realize the application of high-power engine systems on long-distance commercial heavy trucks, and solve the technical problem of insufficient power of the fuel cell engine system.

[0034] Reference Figure 2 The present invention also provides an embodiment of a fuel cell bipolar plate parallel sealing method, which is used to seal the fuel cell bipolar plate parallel sealing device in the above embodiment, and the sealing method comprises: S100, multiple groups of supporting pads 4 are embedded in the insulating sealing pad 3 to form a sealing frame; S200, the first bipolar plate 1 and one or more second bipolar plates 2 are aligned and stacked via the insulating sealing gasket 3 wrapped on the outside to form a multi-layer stacking structure; S300, a plurality of adjacent groups of multi-layer stack structures are stacked vertically and / or flatly and assembled with membrane electrodes to form a plurality of fuel cells.

[0035] Please continue reading Figure 3 In this embodiment, S300 includes: S310, selecting a vertical and / or tiled stacking scheme according to the layout space, and calculating the number of multi-axis stacking groups; S320. The assembly accuracy of the multi-layer stacked structure is positioned through the first inner positioning hole 321 and the second inner positioning hole 322. A membrane electrode is press-fitted between adjacent multi-layer stacked structures to form a parallel multi-stack fuel cell.

[0036] It can be understood that the configurations of such bipolar plate assemblies include but are not limited to vertical stacking and flat stacking, or multi-bipolar plate composite arrangements to form multi-configuration stack bipolar plate combinations. Based on the use of the above single plates, combined with a stack PACK housing that meets the structural strength, together with the high- and low-voltage auxiliary components inside the stack PACK, a fuel cell engine stack PACK module is finally formed for system integration use: During the design process, the limitation of the layout space is an important consideration factor. If the layout space is relatively limited and there are high requirements for space utilization, the flat stacking method can be preferred. This method can increase the number of stack layers in a limited planar area and improve the power output; while in some cases where there are no high requirements for the vertical height and there is sufficient longitudinal space, the vertical stacking method can be preferred, which can make full use of the space in the vertical direction; at the same time, in order to ensure the performance and stability of the entire stack system, it is necessary to calculate the multi-axis stacking groups through parameters such as the rated power of the battery, the required flow rates of the reaction gases and electrolytes, so as to meet the diverse requirements for the stack power and performance in different application scenarios.

[0037] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A parallel sealing device for a fuel cell bipolar plate, characterized in that, Including: A first bipolar plate and a second bipolar plate; The first bipolar plate and one or more of the second bipolar plates are aligned and stacked through an insulating gasket wrapped on the outside to form a multi-layer stacked structure; Multiple groups of support pads are embedded inside the insulating gasket to form a sealing frame, and the support pads are used for limiting and supporting.

2. The fuel cell bipolar plate parallel sealing device according to claim 1, wherein Adjacent multiple groups of the multi-layer stacked structures are vertically and / or tiled and stacked with a membrane electrode assembly to form a multi-stack fuel cell.

3. The fuel cell bipolar plate parallel sealing device according to claim 1, characterized in that, Multiple groups of mounting holes are symmetrically formed at the edge of the insulating gasket, and the support pads are inserted through and embedded in the mounting holes.

4. The fuel cell bipolar plate parallel sealing device according to claim 3, characterized in that, Positioning holes are formed at the diagonal corners of the insulating gasket, and the positioning holes include a first inner positioning hole and a second inner positioning hole.

5. The fuel cell bipolar plate parallel sealing device according to claim 3, wherein The support pads are symmetrically embedded at the edge of the insulating gasket.

6. The fuel cell bipolar plate parallel sealing device according to claim 3, wherein 8-16 groups of support pads are symmetrically arranged, and the cross section of the support pads is rectangular, L-shaped, triangular or arc-shaped.

7. The fuel cell bipolar plate parallel sealing device according to claim 1, wherein Flow field areas are arranged in the middle of the first bipolar plate and the second bipolar plate, and an inlet distribution area and an outlet distribution area are symmetrically arranged on both sides of the flow field area.

8. The fuel cell bipolar plate parallel sealing device according to claim 7, wherein A first three-chamber pipe orifice is arranged outside the inlet distribution area, and the three-chamber pipe orifice includes a hydrogen inlet hole, a water inlet and an air exhaust hole. A second three-chamber pipe orifice is arranged outside the outlet distribution area, and the three-chamber pipe orifice includes an air inlet hole, a water outlet and a hydrogen exhaust hole.

9. A method for parallel sealing of a fuel cell bipolar plate, characterized in that, The sealing method is used to seal the fuel cell bipolar plate parallel sealing device according to any one of claims 1 to 8, and the sealing method includes: S100, multiple groups of support pads are inserted through and embedded inside the insulating gasket to form a sealing frame; S200, the first bipolar plate and one or more second bipolar plates are aligned and stacked through an insulating gasket wrapped on the outside to form a multi-layer stacked structure; S300, adjacent multiple groups of multi-layer stacked structures are vertically and / or tiled and stacked with a membrane electrode assembly to form a multi-stack fuel cell.

10. The fuel cell bipolar plate parallel sealing method according to claim 9, characterized in that, The S300 includes: S310, select a vertical and / or tiled stacking scheme according to the layout space, and calculate the number of multi-axis stacking groups; S320, the multi-layer stacked structure positions the assembly accuracy through the first inner positioning hole and the second inner positioning hole, and presses the membrane electrode between adjacent multi-layer stacked structures to form a parallel multi-stack fuel cell.

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