A sealing structure for a fuel cell stack tower

Abstract

The present invention provides a sealing structure for a fuel cell stack tower, wherein a cathode outlet gas collecting cylinder is provided at the center of a cylindrical structure. A first insulating layer is provided on the top of the cylindrical structure, a ballast block is provided on the first insulating layer, and a first elastic connecting metal plate is provided on the top surface of the ballast block. A heat-insulating sealing block is provided between the fuel cells, a second insulating layer is provided on the top of the heat-insulating sealing block, a metal plate is provided on the second insulating layer, the top surface of the metal plate is flush with the top surface of the ballast block, and a second elastic connecting metal plate is provided on the metal plate. The first elastic metal plate and the second elastic metal plate form an integral structure, and a metal cover plate is provided on the top of the first elastic metal plate and the second elastic metal plate to connect with the cathode outlet gas collecting cylinder. The sealing structure provided by the present invention is a sealing method for preventing the cathode inlet gas from being directly short-circuited to the outlet for an open cathode fuel cell stack, thereby ensuring that the fuel cell stack has good performance and is not damaged, and the stack tower still has good sealing performance under different sedimentation conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell power generation, and in particular to a sealing structure for a fuel cell stack tower. Background Art

[0002] Solid oxide fuel cells consist of an anode, cathode and electrolyte. The anode is fuel gas, which is sealed and supplied by pipes or gas distribution plates. The cathode is generally air or oxidizing gas containing air. As the cathode adopts an open structure, the seal between the cathode inlet and outlet is more important, especially to prevent the cathode inlet and outlet gas from short-circuiting. This will cause the power generation performance of the stack to decline during operation, and in severe cases, the stack will be damaged.

[0003] During the assembly process of the battery stack, due to the problem of inconsistent sealant application between battery cells, or the different expansion between battery cells and battery stack end plates at high temperatures, the height difference between the stack towers will be inconsistent. For circular stack towers, the air at the inlet can easily enter the outlet directly, causing unexpected results for the power generation system. In addition, in the layout design of multiple towers, it is always inevitable to use insulation blocks between the towers. Under high temperature conditions, the thermal expansion of the insulation blocks and the stack towers is also different, which is also a risk of short circuit. In the actual tower stack device, some weight blocks are added to the upper part of the tower. These weight blocks are generally made of solid metal materials, mainly because metal materials have better integrity at high temperatures and are not easy to break. For the battery stack structure with multiple towers, the effect will definitely be greatly affected by the different settlement in the presence of weight blocks. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a sealing structure for a fuel cell stack tower. For an open cathode stack, a sealing method is provided to prevent the cathode inlet gas from directly short-circuiting to the outlet, thereby ensuring that the stack has good performance and is not damaged, and the stack tower still has good sealing performance under different sedimentation conditions.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A sealing structure for a fuel cell stack tower includes a preset number of stacks, which are connected and arranged in sequence to form a complete hollow cylindrical structure. A cathode outlet gas collecting cylinder is provided at the center of the cylindrical structure. A first insulating layer is provided on the top of the cylindrical structure, a ballast block is provided on the first insulating layer, and a first elastic connecting metal plate is provided on the top surface of the ballast block. A heat-insulating sealing block is provided between the stacks, a second insulating layer is provided on the top of the heat-insulating sealing block, a metal plate is provided on the second insulating layer, the top surface of the metal plate is flush with the top surface of the ballast block, and a second elastic connecting metal plate is provided on the metal plate. The first elastic metal plate and the second elastic metal plate form an integral structure, and a metal cover plate is provided on the top of the first elastic metal plate and the second elastic metal plate to connect with the cathode outlet gas collecting cylinder.

[0007] According to the sealing structure for fuel cell stack tower of the present invention, for air-open fuel cell stacks, the elasticity of the elastic metal plate is used to absorb the uneven heights between the stack towers caused by the sedimentation of the fuel cell stack at high temperature, maintain good sealing of the upper and lower end faces of the elastic metal plate, solve the problem of short circuit between the cathode air inlet and cathode air outlet caused by the sedimentation of the stack tower, and ensure the stability of the performance of the fuel cell stack without changing the structure of the fuel cell stack.

[0008] For the above technical solution, further improvements as described below can be made.

[0009] According to the sealing structure for a fuel cell stack tower of the present invention, in a preferred embodiment, both the first insulating layer and the second insulating layer include mica sheets.

[0010] Since mica sheets are made of natural mineral products, they are pollution-free, insulating, and have good voltage resistance. Natural mica sheets of various specifications can be punched out according to demand, and they have insulation and low-loss thermal resistance functions, so they are particularly suitable for use in the sealing structure of fuel cell stack towers.

[0011] Furthermore, in a preferred embodiment, the mica sheet includes 2 to 3 layers.

[0012] By arranging multiple layers of mica sheets, the insulation withstand voltage performance of the insulation layer can be ensured to a great extent.

[0013] Specifically, in a preferred embodiment, the height of the heat insulating sealing block is 3 to 5 mm lower than the height of the ballast block.

[0014] By setting the above structure, it is convenient to arrange the second insulating layer with a suitable thickness.

[0015] Correspondingly, in a preferred embodiment, the height of the second insulating layer is not less than 3 mm.

[0016] By setting the thickness of the second insulating layer within the above range, the insulation withstand voltage performance of the insulating layer can be ensured to a great extent.

[0017] Further, in a preferred embodiment, the first elastic metal plate and the second elastic metal plate are both corrugated steel plates.

[0018] The use of corrugated steel plates as elastic connecting plates is very helpful in absorbing the uneven heights between the stacks caused by the settling of the fuel cell stack under high temperature.

[0019] Specifically, in a preferred embodiment, the first elastic metal plate and the second elastic metal plate are respectively connected to the ballast block, the metal plate and the metal cover plate by welding.

[0020] The above components are connected to each other by welding, which is beneficial to ensuring the sealing performance of the entire sealing structure.

[0021] Specifically, in a preferred embodiment, the first elastic metal plate and the second elastic metal plate are both connected to the cathode outlet gas collecting cylinder by welding.

[0022] The welding method between the top of the fuel cell stack and the cathode outlet gas collecting cylinder is also beneficial to ensure the sealing performance of the entire sealing structure.

[0023] Specifically, in a preferred embodiment, a sealant layer is applied between the first insulating layers, between the first insulating layer and the ballast block, between the second insulating layers, between the second insulating layer and the metal plate, and between the second insulating layer and the heat-insulating sealing block.

[0024] By applying high temperature resistant sealant between various layers and gaps, the sealing performance of the entire sealing structure can be ensured to the greatest extent.

[0025] Specifically, in a preferred embodiment, a mounting hole is provided at the center of the metal cover plate to match the outer periphery of the cathode outlet gas collecting cylinder.

[0026] By arranging a mounting hole in the center of the metal cover plate, the assembly of the entire sealing structure is facilitated.

[0027] Compared with the prior art, the advantages of the present invention are: for air-open fuel cells, the elasticity of the elastic metal plate can absorb the uneven heights between the stack towers caused by the sedimentation of the fuel cell stack at high temperature, maintain good sealing of the upper and lower end surfaces of the elastic metal plate, solve the problem of short circuit between the cathode air inlet and cathode air outlet caused by the sedimentation of the stack tower, ensure the stability of the performance of the fuel cell stack, and there is no need to change the structure of the fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein:

[0029] Figure 1The first partial structure of the sealing structure according to the embodiment of the present invention is schematically shown;

[0030] Figure 2 The overall structure of the sealing structure according to the embodiment of the present invention is schematically shown;

[0031] Figure 3 The second structure of the sealing structure according to the embodiment of the present invention is schematically shown;

[0032] Figure 4 A structure of a corrugated plate according to an embodiment of the present invention is schematically shown;

[0033] Figure 5 Another structure of the corrugated plate according to an embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

[0035] Figure 1 The first partial structure of the sealing structure 10 according to the embodiment of the present invention is schematically shown. Figure 2 The overall structure of the sealing structure 10 according to the embodiment of the present invention is schematically shown. Figure 3 A second partial structure of the sealing structure 10 according to the embodiment of the present invention is schematically shown. Figure 4 A structure of a corrugated plate according to an embodiment of the present invention is schematically shown. Figure 5 Another structure of the corrugated plate according to an embodiment of the present invention is schematically shown.

[0036] like Figures 1 to 3 As shown, the sealing structure 10 for the fuel cell stack tower of the embodiment of the present invention includes a preset number of stacks 1, which are arranged in sequence to form a complete hollow cylindrical structure. Among them, a cathode outlet gas collecting cylinder 2 is provided at the center of the cylindrical structure. A first insulating layer 3 is provided on the top of the cylindrical structure, a ballast block 4 is provided on the first insulating layer 3, and a first elastic connecting metal plate 5 is provided on the top surface of the ballast block 4. An insulating sealing block 6 is provided between the stacks 1, a second insulating layer 7 is provided on the top of the insulating sealing block 6, a metal plate 8 is provided on the second insulating layer 7, the top surface of the metal plate 8 is flush with the top surface of the ballast block 4, and a second elastic connecting metal plate 9 is provided on the metal plate 8. The first elastic metal plate 5 and the second elastic metal plate 9 form an integral structure, and a metal cover plate 101 is provided on the top of the first elastic metal plate 5 and the second elastic metal plate 9 to connect with the cathode outlet gas collecting cylinder 2.

[0037] According to the sealing structure for the fuel cell stack tower of an embodiment of the present invention, for an air-open fuel cell stack, the elasticity of the elastic metal plate is used to absorb the uneven heights between the stack towers caused by the sedimentation of the fuel cell stack under high temperature, thereby maintaining good sealing of the upper and lower end surfaces of the elastic metal plate, solving the problem of short circuit between the cathode air inlet and cathode air outlet caused by the sedimentation of the stack tower, and ensuring the stability of the performance of the fuel cell stack without changing the structure of the fuel cell stack.

[0038] Specifically, in this embodiment, a mounting hole is provided in the center of the metal cover plate 101 to match the outer periphery of the cathode outlet gas collecting cylinder 2. By providing the mounting hole in the center of the metal cover plate, the assembly of the entire sealing structure is facilitated.

[0039] Specifically, in the present embodiment, the first insulating layer 3 and the second insulating layer 7 both include mica sheets. Since the mica sheet is made of natural mineral products, it has the characteristics of being pollution-free, insulating, and having good voltage resistance. Natural mica sheets of various specifications can be punched out according to demand, and have insulation and low-loss thermal resistance functions, and are therefore particularly suitable for use in the sealing structure of a fuel cell stack tower. Furthermore, in the present embodiment, the mica sheet includes 2 to 3 layers. By providing multiple layers of mica sheets, the insulation and voltage resistance performance of the insulating layer can be ensured to a great extent.

[0040] Specifically, in this embodiment, the height of the heat-insulating sealing block 6 is 3 to 5 mm lower than the height of the weight block 4. By setting the above structure, it is convenient to arrange a second insulating layer of appropriate thickness. Correspondingly, in this embodiment, the height of the second insulating layer 7 is not less than 3 mm. Setting the thickness of the second insulating layer within the above range can ensure the insulation withstand voltage performance of the insulating layer to a great extent.

[0041] Furthermore, in this embodiment, the first elastic metal plate 5 and the second elastic metal plate 9 are both corrugated steel plates. Using corrugated steel plates as elastic connecting plates is very conducive to absorbing the uneven heights between the stacks caused by the sedimentation of the battery stack at high temperatures. Specifically, in this embodiment, the thickness of the corrugated plate is preferably 3 to 5 mm, resistant to high temperatures of 800°C, with a tensile strength of not less than 520 MPa and a yield strength of not less than 205 MPa. Specifically, in this embodiment, Figure 4 As shown in the figure, the corrugated plate is a wave-shaped folded structure. Figure 5 As shown, in this embodiment, the corrugated plate can also be a toothed folding structure. The corrugated plates of the above two structures can well realize elastic connection with the weight block, the metal plate and the metal cover plate, and can ensure the stability and reliability of the entire connection structure.

[0042] Specifically, in this embodiment, the first elastic metal plate 5 and the second elastic metal plate 9 are respectively connected to the ballast block 4, the metal plate 8 and the metal cover plate 101 by welding. The above-mentioned components are connected to each other by welding, which is conducive to ensuring the sealing performance of the entire sealing structure. Specifically, in this embodiment, the first elastic metal plate 5 and the second elastic metal plate 9 are connected to the cathode outlet gas collecting cylinder by welding. The welding method between the top of the stack and the cathode outlet gas collecting cylinder is also conducive to ensuring the sealing performance of the entire sealing structure.

[0043] Specifically, in this embodiment, a sealant layer is applied between the first insulating layers 3, between the first insulating layer 3 and the ballast block 4, between the second insulating layers 7, between the second insulating layer 7 and the metal plate 8, and between the second insulating layer 7 and the heat-insulating sealing block 6. By applying high-temperature resistant sealant between various layers and gaps, the sealing performance of the entire sealing structure can be ensured to a great extent.

[0044] According to the above embodiments, it can be seen that the sealing structure for the fuel cell stack tower involved in the present invention, for an air-open fuel cell stack, absorbs the uneven height between the stack towers caused by the sedimentation of the fuel cell stack under high temperature through the elasticity of the elastic metal plate, maintains good sealing of the upper and lower end surfaces of the elastic metal plate, solves the problem of short circuit between the cathode air inlet and cathode air outlet caused by the sedimentation of the stack tower, ensures the stability of the performance of the fuel cell stack, and does not need to change the structure of the fuel cell stack.

[0045] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A sealing structure for a fuel cell stack tower, characterized in that: It includes a preset number of battery stacks, which are sequentially connected and arranged to form a complete hollow cylindrical structure; wherein, A cathode outlet gas collecting cylinder is provided at the center of the cylindrical structure; A first insulating layer is provided on the top of the cylindrical structure, a weight block is provided on the first insulating layer, and a first elastic connecting metal plate is provided on the top surface of the weight block; A heat-insulating sealing block is provided between the battery stacks, a second insulating layer is provided on the top of the heat-insulating sealing block, a metal plate is provided on the second insulating layer, the top surface of the metal plate is flush with the top surface of the ballast block, and a second elastic connecting metal plate is provided on the metal plate; The first elastic metal plate and the second elastic metal plate form an integral structure, and metal cover plates are arranged on the top of the first elastic metal plate and the second elastic metal plate to be connected with the cathode outlet gas collecting cylinder.

2. The sealing structure for a fuel cell stack tower according to claim 1, characterized in that: The first insulating layer and the second insulating layer both include mica sheets.

3. The sealing structure for a fuel cell stack tower according to claim 2, characterized in that: The mica sheet comprises 2 to 3 layers.

4. The sealing structure for a fuel cell stack tower according to any one of claims 1 to 3, characterized in that: The height of the heat-insulating sealing block is 3 to 5 mm lower than the height of the ballast block.

5. The sealing structure for a fuel cell stack tower according to claim 4, characterized in that: The height of the second insulating layer is not less than 3 mm.

6. The sealing structure for a fuel cell stack tower according to any one of claims 1 to 3, characterized in that: The first elastic metal plate and the second elastic metal plate are both corrugated steel plates.

7. The sealing structure for a fuel cell stack tower according to any one of claims 1 to 3, characterized in that: The first elastic metal plate and the second elastic metal plate are respectively connected to the weight block, the metal plate and the metal cover plate by welding.

8. The sealing structure for a fuel cell stack tower according to any one of claims 1 to 3, characterized in that: The first elastic metal plate and the second elastic metal plate are both connected to the cathode outlet gas collecting cylinder by welding.

9. The sealing structure for a fuel cell stack tower according to any one of claims 1 to 3, characterized in that: A sealant layer is applied between the first insulating layers, between the first insulating layer and the ballast block, between the second insulating layers, between the second insulating layer and the metal plate, and between the second insulating layer and the heat-insulating sealing block.

10. The sealing structure for a fuel cell stack tower according to any one of claims 1 to 3, characterized in that: A mounting hole is provided at the center of the metal cover plate to match the outer periphery of the cathode outlet gas collecting cylinder.

Images