An inlet end plate structure for a fuel cell stack

Abstract

The application discloses an air inlet end plate structure for a fuel cell stack, comprising a metal end plate and an insulating end plate, the metal end plate and the insulating end plate being a two-layer cooperating structure, one end of which is provided with an air inlet and a hydrogen outlet, and the other end of which is provided with an air outlet and a hydrogen inlet, the upper end and the lower end of which are respectively a coolant inlet and a coolant outlet; the metal end plate comprises reinforcing rib bosses, fluid inlet and outlet through holes, positioning holes and fastening holes; the insulating end plate comprises reinforcing rib grooves, fluid inlet and outlet bosses, air inlet through holes, hydrogen inlet grooves, coolant inlet grooves, air outlet through holes, hydrogen outlet grooves, coolant outlet grooves, positioning holes and sealing grooves. The application has the beneficial effect that the application sets reinforcing ribs between the metal end plate and the insulating end plate, increases the strength of the end plate structure of the fuel cell stack, reduces the deformation amount, and makes the contact pressure distribution of the bipolar plate and the membrane electrode in the stack uniform.

Description

Technical Field

[0001] This invention relates to the field of fuel cell stack end plates, and in particular to an air inlet end plate structure for fuel cell stacks. Background Technology

[0002] End plates are one of the main components of a fuel cell stack. Their primary function is to secure the fuel cell stack and distribute fluids, while insulating plates primarily provide insulation. Both end plates and insulating plates have hydrogen, air, and coolant inlets / outlets. Therefore, end plates and insulating plates are designed with openings and grooves according to fluid distribution requirements. Furthermore, most fuel cell stacks have their fastening stress points distributed around the end plates, making them prone to large deformations and low overall rigidity. During long-term use, fuel cell stack end plates are susceptible to deformation due to uneven stress or difficulty in continuously transmitting and distributing external forces, leading to a decrease in the fuel cell stack's sealing performance. In addition to maintaining a good seal, it is also necessary to maintain uniform stress in the active area. Current is transmitted between the bipolar plates and the membrane electrode assembly (MEA) through contact, generating contact resistance at the interface. Large localized deformation of the end plate can lead to uneven pressure distribution between the bipolar plates and MEA, increasing contact resistance and affecting the overall output performance of the fuel cell stack. Furthermore, when gas and coolant enter the endplate, uniform distribution needs to be considered. Uneven water distribution at the endplate inlet and outlet will lead to a decrease in cooling effect. Additionally, coolant fluid distribution channels must be correspondingly provided on the endplate. Localized reduction in endplate strength and increased flow resistance will also increase the power required by the fuel cell stack. Simultaneously, if water and gas are in direct contact with the metal endplate, the insulation resistance of the fuel cell stack will fail to meet standards. Therefore, how to design endplates with excellent mechanical properties, corrosion resistance, insulation performance, low power consumption, and uniform fluid distribution performance is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems by designing an air inlet end plate structure for fuel cell stacks.

[0004] The technical solution of the present invention to achieve the above objectives is an air inlet end plate structure for a fuel cell stack, comprising a metal end plate and an insulating end plate, wherein the metal end plate and the insulating end plate are a two-layer mating structure, one end is provided with an air inlet and a hydrogen outlet, and the other end is provided with an air outlet and a hydrogen inlet.

[0005] The upper and lower ends of the metal end plate and the insulating end plate are the coolant inlet and the coolant outlet, respectively.

[0006] The metal end plate includes a reinforcing rib boss, fluid inlet and outlet through holes, positioning holes, and fastening holes;

[0007] The insulating end plate includes a reinforcing rib groove, fluid inlet and outlet bosses, air inlet through hole, hydrogen inlet groove, coolant inlet groove, air outlet through hole, hydrogen outlet groove, coolant outlet groove, positioning hole and sealing groove.

[0008] The metal end plate has reinforcing ribs at the fluid inlet and outlet through holes, and the insulating end plate has several fluid inlet and outlet bosses. The fluid inlet and outlet bosses of the insulating end plate have reinforcing rib grooves. When the metal end plate and the insulating end plate are fitted together, each reinforcing rib is inserted into the corresponding reinforcing rib groove. The depth of the reinforcing rib groove is greater than or equal to the height of the reinforcing rib boss, so that the metal end plate and the insulating end plate are fully fitted together.

[0009] The metal end plate is provided with a number of fluid inlet and outlet through holes. When the metal end plate and the insulating end plate are fitted together, each fluid inlet and outlet boss is inserted into the fluid inlet and outlet through hole corresponding to its position. The height of the fluid inlet and outlet boss is greater than or equal to the thickness of the metal end plate.

[0010] The insulating end plate is provided with two coolant inlet slots and two coolant outlet slots, with a funnel-shaped cross-section. Both the coolant inlet slots and coolant outlet slots are equipped with baffles, dividing the slot chamber into two. A triangular diversion structure is provided above the baffles.

[0011] The angle of the triangular flow divider structure is the same as the angle of the funnel shape of the coolant inlet tank, that is, the upper interface of the triangular flow divider structure is parallel to the lower interface of the coolant inlet tank.

[0012] The air inlet and air outlet of the insulating end plate are through holes, and the hydrogen inlet and hydrogen outlet are provided with grooves. The grooves have a right-angled trapezoidal cross-section, and the right-angled side of the trapezoid is parallel to one side of the air inlet and outlet through holes.

[0013] The point where the hydrogen inlet groove and the hydrogen inlet boss are connected is located at the acute angle of a right triangle; the point where the hydrogen outlet groove and the hydrogen outlet boss are connected is located at the acute angle of a right triangle.

[0014] The upper surface of the fluid inlet and outlet protrusions of the insulating end plate is provided with a sealing groove for connecting external sealing pipes and sealing adhesive lines. The lower surface of the insulating end plate is provided with a sealing groove for connecting the manifold and sealing adhesive lines.

[0015] The metal end plate and the insulating end plate are provided with two positioning holes in the same position for positioning when the metal end plate and the insulating end plate are mated.

[0016] The present invention provides an air inlet end plate structure for a fuel cell stack. By setting reinforcing ribs between the metal end plate and the insulating end plate, the present invention increases the structural strength of the fuel cell stack end plate, reduces its deformation, and makes the contact pressure distribution between the bipolar plate and the membrane electrode inside the stack uniform.

[0017] This invention reduces the overall deformation of the sealing area by setting reinforcing ribs at the fluid inlet and outlet seals, thus ensuring the sealing performance of the fuel cell stack.

[0018] The present invention has a partition in the coolant inlet and outlet tanks and a triangular diversion structure at the inlet, so that the fluid is evenly distributed in two parts to ensure that the coolant is evenly distributed inside the fuel cell stack and achieve better thermal management.

[0019] The coolant inlet trough of this invention is equipped with a triangular flow-diverting structure, which allows the coolant to directly enter the common channel of the fuel cell stack. Compared with a grooved flow channel, the flow resistance is smaller, which significantly reduces the coolant inlet pressure and reduces the power required outside the fuel cell stack.

[0020] The air inlet and outlet of this invention are through-hole structures, while the hydrogen inlet and outlet are right-angled trapezoidal groove structures. The hydrogen inlet is a release design, which releases the instantaneous pressure of the fluid entering the fuel cell stack and reduces the power required outside the stack.

[0021] This invention features fluid inlet and outlet bosses on the insulating end plate. During the process of reactant gas and coolant entering and exiting the fuel cell, they only come into contact with the insulating end plate and are completely isolated from the metal end plate. Therefore, the inlet end plate is not affected by corrosion, ensuring high safety and effectively extending the service life of the fuel cell. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the air inlet end plate structure for a fuel cell stack according to the present invention.

[0023] Figure 2 This is a top view of the air inlet end plate structure for a fuel cell stack according to the present invention.

[0024] Figure 3 This is a bottom view of the air inlet end plate structure for a fuel cell stack according to the present invention.

[0025] Figure 4 This invention relates to an air inlet endplate structure for a fuel cell stack. Figure 2 Sectional view of section AA.

[0026] Figure 5 This invention relates to an air inlet endplate structure for a fuel cell stack. Figure 2 Sectional view of section BB.

[0027] Figure 6 This is a schematic diagram of a metal end plate for an air inlet end plate structure of a fuel cell stack according to the present invention.

[0028] Figure 7 This is a schematic diagram of an insulating end plate for an air inlet end plate structure for a fuel cell stack according to the present invention.

[0029] In the diagram: 1-Metal end plate, 2-Insulating end plate, 3-Air inlet, 4-Hydrogen inlet, 5-Coolant inlet, 6-Air outlet, 7-Hydrogen outlet, 8-Coolant outlet, 9-Positioning hole, 10-Air inlet through hole, 11-Hydrogen inlet groove, 12-Coolant inlet groove, 13-Air outlet through hole, 14-Hydrogen outlet groove, 15-Coolant outlet groove, 16-Sealing groove, 17-Coolant diverter block, 18-Block, 19-Reinforcing rib, 20-Fluid inlet / outlet through hole, 21-Reinforcing rib groove, 22-Fluid inlet / outlet boss, 23-Fasting hole. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings, such as... Figure 1-7 As shown, an air inlet end plate structure for a fuel cell stack includes a metal end plate 1 and an insulating end plate 2. The metal end plate 1 and the insulating end plate 2 are a two-layer mating structure. One end is provided with an air inlet 3 and a hydrogen outlet 7, and the other end is provided with an air outlet 6 and a hydrogen inlet 4.

[0031] The upper and lower ends of the metal end plate 1 and the insulating end plate 2 are respectively the coolant inlet 5 and the coolant outlet 8;

[0032] Metal end plate 1 includes a reinforcing rib boss, fluid inlet / outlet through holes 20, positioning holes 9, and fastening holes 23;

[0033] The insulating end plate 2 includes a reinforcing rib groove, a fluid inlet / outlet boss 22, an air inlet through hole 10, a hydrogen inlet groove 11, a coolant inlet groove 12, an air outlet through hole 13, a hydrogen outlet groove 14, a coolant outlet groove 15, a positioning hole 9, and a sealing groove 16.

[0034] As a preferred technical solution, the metal end plate 1 is further provided with a reinforcing rib 19 at the fluid inlet / outlet through hole 20, and the insulating end plate 2 is provided with a plurality of fluid inlet / outlet bosses 22. The fluid inlet / outlet bosses 22 of the insulating end plate 2 are provided with reinforcing rib grooves 21. When the metal end plate 1 and the insulating end plate 2 are fitted together, each reinforcing rib 19 is inserted into the reinforcing rib groove 21 corresponding to its position. The depth of the reinforcing rib groove 21 is greater than or equal to the height of the reinforcing rib boss, so that the metal end plate 1 and the insulating end plate 2 are fully fitted together.

[0035] As a preferred technical solution, the metal end plate 1 is further provided with a number of fluid inlet and outlet through holes 20. When the metal end plate 1 and the insulating end plate 2 are fitted together, each fluid inlet and outlet boss 22 is inserted into the fluid inlet and outlet through hole 20 corresponding to the position. The height of the fluid inlet and outlet boss 22 is greater than or equal to the thickness of the metal end plate 1.

[0036] As a preferred technical solution, the insulating end plate 2 is further provided with two coolant inlet slots 12 and two coolant outlet slots 15, with a funnel-shaped cross section. Both the coolant inlet slots 12 and the coolant outlet slots 15 are provided with baffles 18, which divide the slots into two. A triangular diversion structure 17 is provided above the baffles 18.

[0037] As a preferred technical solution, the angle of the triangular flow splitting structure 17 is the same as the horn-shaped angle of the coolant inlet tank 12, that is, the upper interface of the triangular flow splitting structure 17 is parallel to the lower interface of the coolant inlet tank 12.

[0038] As a preferred technical solution, the air inlet 3 and air outlet 6 in the insulating end plate 2 are through holes, and the hydrogen inlet 4 and hydrogen outlet 7 are provided with grooves. The grooves have a right-angled trapezoidal cross-section, and the right-angled side of the trapezoid is parallel to one side of the air inlet and outlet through holes.

[0039] As a preferred technical solution, the through connection between the hydrogen inlet groove 11 and the hydrogen inlet 4 boss is located at the acute angle of a right triangle; the through connection between the hydrogen outlet groove 14 and the hydrogen outlet 7 boss is located at the acute angle of a right triangle.

[0040] As a preferred technical solution, the upper surface of the fluid inlet and outlet bosses 22 of the insulating end plate 2 is provided with a sealing groove 16 for connecting the external sealing pipe and sealing glue line, and the lower surface of the insulating end plate 2 is provided with a sealing groove 16 for connecting the manifold and sealing glue line.

[0041] As a preferred technical solution, the metal end plate 1 and the insulating end plate 2 are further provided with two positioning holes 9 at the same position for positioning when the metal end plate 1 and the insulating end plate 2 are engaged.

[0042] The features of this implementation plan are:

[0043] 1. A reinforcing rib is provided between the metal end plate 1 and the insulating end plate 2 to increase the structural strength of the fuel cell stack end plate and reduce its deformation. This ensures that the contact pressure between the bipolar plate and the membrane electrode inside the stack is uniform and also guarantees the sealing performance of the fuel cell stack.

[0044] 2. The coolant inlet and outlet tanks are equipped with baffles 18, and a triangular flow divider structure 17 is provided at the inlet. The coolant can be evenly distributed into two parts inside the fuel cell stack, achieving better thermal management. At the same time, the coolant directly enters the common channel of the fuel cell stack, resulting in lower flow resistance and reducing the power required outside the fuel cell stack.

[0045] 3. The air inlet and outlet are through holes, and the hydrogen inlet and outlet are right-angled trapezoidal grooves. The hydrogen inlet (4) is a release design, which releases the instantaneous pressure of the fluid entering the fuel cell stack and reduces the power required outside the stack.

[0046] Example 1:

[0047] The air intake end plate provided in this embodiment of the invention has a reinforcing rib structure. The metal end plate 1 is made of AL6061 material, and the insulating end plate 2 is made of epoxy resin material. The height of the reinforcing rib of the metal end plate 1 is 4.9mm, the groove depth of the reinforcing rib of the insulating plate is 5mm, the power of the fuel cell stack is 150kw, and after applying the assembly force required for the fuel cell stack, the deformation is reduced by 45.8% compared with the air intake end plate without reinforcing ribs.

[0048] Example 2:

[0049] The air intake end plate provided in this embodiment of the invention has 10 end plate fastening holes 23 distributed around its perimeter. The end plate can be fastened by a tie rod, with the fastening holes 23 being Φ8 threaded holes, or by a bolt, with the fastening holes 23 being Φ11 through holes. Under the working condition of Embodiment 1, with both of these methods, the deformation of the air intake end plate is within the range of less than 0.1mm, which provides an effective guarantee for the safe operation of the fuel cell stack.

[0050] The above technical solutions only embody the preferred technical solutions of the present invention. Any modifications that may be made by those skilled in the art to certain parts thereof embody the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. An air inlet endplate structure for a fuel cell stack, characterized in that, It includes a metal end plate (1) and an insulating end plate (2). The metal end plate (1) and the insulating end plate (2) are a two-layer mating structure. One end is provided with an air inlet (3) and a hydrogen outlet (7), and the other end is provided with an air outlet (6) and a hydrogen inlet (4). The upper and lower ends of the metal end plate (1) and the insulating end plate (2) are respectively the coolant inlet (5) and the coolant outlet (8); The metal end plate (1) includes a reinforcing rib boss, fluid inlet and outlet through holes (20), positioning holes (9) and fastening holes (23). The insulating end plate (2) includes a reinforcing rib groove, a fluid inlet and outlet boss (22), an air inlet through hole (10), a hydrogen inlet groove (11), a coolant inlet groove (12), an air outlet through hole (13), a hydrogen outlet groove (14), a coolant outlet groove (15), a positioning hole (9), and a sealing groove (16). The metal end plate (1) has a reinforcing rib (19) at the fluid inlet / outlet through hole (20), and the insulating end plate (2) has a plurality of fluid inlet / outlet bosses (22). The insulating end plate (2) has a reinforcing rib groove (21) at the fluid inlet / outlet bosses (22). When the metal end plate (1) and the insulating end plate (2) are fitted together, each reinforcing rib (19) is inserted into the corresponding reinforcing rib groove (21). The depth of the reinforcing rib groove (21) is greater than or equal to the height of the reinforcing rib boss, so that the metal end plate (1) and the insulating end plate (2) are fully fitted together. The metal end plate (1) is provided with a plurality of fluid inlet and outlet through holes (20). When the metal end plate (1) and the insulating end plate (2) are fitted together, each fluid inlet and outlet boss (22) is inserted into the fluid inlet and outlet through hole (20) corresponding to the position. The height of the fluid inlet and outlet boss (22) is greater than or equal to the thickness of the metal end plate (1). The insulating end plate (2) is provided with two coolant inlet slots (12) and two coolant outlet slots (15), with a funnel-shaped cross section. Both the coolant inlet slots (12) and the coolant outlet slots (15) are provided with baffles (18) to divide the slot into two. A triangular diversion structure is provided above the baffles (18) of the coolant inlet slots (12). The angle of the triangular flow splitting structure is the same as the horn-shaped angle of the coolant inlet groove (12), that is, the upper interface of the triangular flow splitting structure is parallel to the lower interface of the coolant inlet groove (12); The air inlet (3) and air outlet (6) of the insulating end plate (2) are through holes, and the hydrogen inlet (4) and hydrogen outlet (7) are provided with grooves. The grooves have a right-angled trapezoidal cross section, and the right-angled side of the right-angled trapezoid is parallel to one side of the air inlet and outlet through holes. The point where the hydrogen inlet groove (11) and the hydrogen inlet (4) protrusion are connected is located at the acute angle of a right triangle; the point where the hydrogen outlet groove (14) and the hydrogen outlet (7) protrusion are connected is located at the acute angle of a right triangle.

2. The inlet end plate structure for a fuel cell stack according to claim 1, characterized in that, The upper surface of the fluid inlet and outlet boss (22) of the insulating end plate (2) is provided with a sealing groove (16) for connecting the external sealing pipe and sealing glue line. The lower surface of the insulating end plate (2) is provided with a sealing groove (16) for connecting the manifold and sealing glue line.

3. The inlet end plate structure for a fuel cell stack according to claim 1, characterized in that, The metal end plate (1) and the insulating end plate (2) are provided with two positioning holes (9) in the same position for positioning when the metal end plate (1) and the insulating end plate (2) are engaged.

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