Solid oxide fuel cell connector and single cell

Abstract

The utility model discloses a solid oxide fuel cell connector and a single cell, the connector comprises a pole plate body, the pole plate body is provided with a resistance flow channel area, parallel linear flow channels are uniformly distributed in the resistance flow channel area, each linear flow channel is internally provided with a plurality of trapezoidal turbulent flow bodies, and the trapezoidal turbulent flow bodies are arranged in the resistance flow channel area. The interval between every two adjacent trapezoidal turbulent flow bodies is reduced in sequence in the flowing direction of the raw material gas, so that the multiple trapezoidal turbulent flow bodies are distributed in the runner in a sparse and dense manner; according to the utility model, the trapezoidal turbulent flow blocks are arranged in the traditional linear flow channel to form trapezoidal resistance, and the effective contact efficiency of raw material gas of a fuel cell and an electrolytic tank and an electrode can be improved by virtue of the trapezoidal resistance layout flow channel design, so that advection raw materials form turbulent flow to radially flow to the electrode under the existence of the trapezoidal resistance; turbulence can be utilized to strengthen delivery and reaction processes.

Description

Technical Field

[0001] This utility model belongs to the field of fuel cell technology, specifically relating to a stainless steel connector flow channel for a solid oxide fuel cell. Background Technology

[0002] The statements herein provide only background information related to this invention and do not necessarily constitute prior art.

[0003] Solid oxide fuel cells (SOFCs) belong to the third generation of fuel cells. They are all-solid-state chemical power generation devices that efficiently and environmentally convert the chemical energy stored in fuel and oxidant into electrical energy directly at medium to high temperatures. Among various types of fuel cells, SOFCs have the highest theoretical energy density and are widely considered to be a type of fuel cell that will be as widely used as proton exchange membrane fuel cells (PEMFCs) in the future. Before commercialization, SOFCs still have some issues that need to be addressed. For example, the working principle of a SOFC involves hydrogen under high temperature and pressure entering the fuel cell through a stainless steel flow channel, reacting with the electrode to produce water, releasing electrical and thermal energy. The water vapor is discharged from the fuel cell along with the remaining hydrogen, and after cooling, gas-liquid separation, and simple purification, the hydrogen re-enters the fuel cell for further reaction. Therefore, flow channel design is a crucial measure to improve the hydrogen reaction conversion rate and thus the power generation efficiency of SOFC fuel cells.

[0004] Existing connectors all use parallel straight-line flow channels. For example, Chinese utility model patent CN218351507U discloses a connector for a solid oxide fuel cell. A flow channel area is provided on the surface of the electrode body, and parallel straight-line flow channels are arranged in the flow channel area. It achieves the purpose of regulating the feed gas flow rate by improving the contour of the flow channel area and setting up turbulence blocks. However, the connector structure of this structure concentrates the turbulence blocks, which has the problem of uneven feed gas entering the flow channel. This affects the diffusion of feed gas in the flow channel, resulting in poor flow of feed gas in the flow channel and affecting the performance of the fuel cell. Utility Model Content

[0005] The purpose of this invention is to provide a solid oxide fuel cell connector and a cell. By setting a trapezoidal turbulence block in a conventional straight flow channel to form a trapezoidal resistance, the horizontally flowing raw material is transformed into a turbulent radial flow towards the electrode under the presence of the trapezoidal resistance. The turbulence can be used to enhance the transfer and reaction processes.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] In a first aspect, embodiments of this utility model provide a solid oxide fuel cell connector, including an electrode body. The electrode body is provided with a resistance flow channel region, in which parallel straight flow channels are uniformly distributed. Each straight flow channel is provided with multiple trapezoidal turbulent fluids, and the interval between two adjacent trapezoidal turbulent fluids decreases sequentially along the flow direction of the feed gas, so that the multiple trapezoidal turbulent fluids are distributed in the flow channel in a manner that is first sparse and then dense.

[0008] As a further technical solution, the width of the trapezoidal turbulent fluid is equal to the width of the straight flow channel, and the height of the trapezoidal turbulent fluid is less than the height of the straight flow channel.

[0009] As a further technical solution, a groove is provided on the surface of the electrode body, and the resistance flow channel area is located in the groove.

[0010] As a further technical solution, the groove is also provided with a raw material gas inlet and a raw material gas outlet, which are located at both ends of the resistance flow channel area.

[0011] As a further technical solution, both the raw gas inlet and the raw gas outlet are oblong in shape.

[0012] As a further technical solution, the electrode body is made of stainless steel or titanium alloy square plate.

[0013] As a further technical solution, fixing screw holes are provided at the four corners of the electrode plate body.

[0014] As a further technical solution, the interval between the two trapezoidal turbulent fluids is reduced to two-thirds of the previous interval each time, and no trapezoidal turbulent fluids are provided at the inlet and outlet of the straight flow channel.

[0015] Secondly, embodiments of this utility model provide a battery cell, including a first electrode body, a composite cell, and a second electrode body arranged sequentially. The first electrode body and the second electrode body have the same structure, both being the solid oxide fuel cell connector described in the first aspect. The straight flow channels of the first electrode body and the straight flow channels of the second electrode body are arranged perpendicularly to each other.

[0016] As a further technical solution, the first electrode plate body, the composite cell, and the second electrode plate body are fixed by screws, and the first electrode plate body and the composite cell, as well as the composite cell and the second electrode plate body, are sealed and connected by sealing insulating material.

[0017] The beneficial effects of the above-described embodiments of this utility model are as follows:

[0018] The solid oxide fuel cell connector provided by this utility model forms a trapezoidal resistance by setting a trapezoidal turbulence block in the conventional straight flow channel. The trapezoidal resistance layout flow channel design can improve the effective contact efficiency between the feed gas and the electrode in the fuel cell and electrolyzer. The horizontal feed gas is transformed into turbulent radial flow towards the electrode under the presence of the trapezoidal resistance, and the turbulence can be used to enhance the transfer and reaction process.

[0019] The solid oxide fuel cell connector provided by this utility model has trapezoidal turbulent fluids placed in the flow channel, which eliminates the problem of uneven feed gas entering the flow channel. The trapezoidal turbulent blocks in the flow channel have a resistance layout that is first sparse and then dense, which can improve the efficiency of gas diffusion in the flow channel and improve the disadvantage of poor flow of feed fluid in the stack, thereby improving the performance of the fuel cell.

[0020] The solid oxide fuel cell connector provided by this invention is applicable not only to solid oxide fuel cells / electrolytes but also to PEM fuel cells / electrolytes, and has a wide range of applications. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0022] Figure 1 This is a schematic diagram of the overall structure of the solid oxide fuel cell connector of this utility model;

[0023] Figure 2 This is a schematic diagram of the flow channel cross-section of this utility model;

[0024] Figure 3 This is a three-dimensional exploded view of the battery cell of this utility model;

[0025] Figure 4 This is a schematic diagram of the overall structure of the battery cell of this utility model;

[0026] Figure 5 This is a cross-sectional view of the battery cell of this utility model.

[0027] The diagram is for illustrative purposes only.

[0028] Among them, 1. Fuel gas outlet; 2. Fixing screw hole; 3. Air outlet; 4. Fuel gas inlet; 5. Air inlet; 6. Resistance flow channel area; 7. Straight flow channel; 8. Trapezoidal turbulence; 9. First electrode plate body; 10. Membrane electrode; 11. Sealing gasket; 12. Second electrode plate body; 13. Fuel gas flow channel; 14. Air flow channel. Detailed Implementation

[0029] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] Example 1

[0031] In a typical embodiment of this utility model, such as Figure 1 and Figure 2 As shown, a solid oxide fuel cell connector is provided, including an electrode body. The electrode body is provided with a resistance flow channel region 6. Parallel straight flow channels 7 are uniformly distributed in the resistance flow channel region. Multiple trapezoidal turbulent fluids 8 are provided in each straight flow channel 7. The interval between two adjacent trapezoidal turbulent fluids 8 decreases sequentially along the flow direction of the feed gas, so that the multiple trapezoidal turbulent fluids are distributed in the flow channel in a first sparse and then dense manner.

[0032] Furthermore, the width of the trapezoidal turbulent fluid 8 is equal to the width of the straight flow channel, and the height of the trapezoidal turbulent fluid is less than the height of the straight flow channel. Square turbulent fluids cause greater resistance during water vapor flow, while semi-circular or arc-shaped turbulent fluids present machining difficulties. Therefore, the trapezoidal turbulent fluid satisfies both functional and production requirements.

[0033] Furthermore, a groove is provided on the surface of the electrode body, and the resistance flow channel area is located within the groove.

[0034] Furthermore, the groove is also provided with a raw material gas inlet and a raw material gas outlet, which are located at opposite ends of the resistance flow channel region. Furthermore, both the raw material gas inlet and the raw material gas outlet are oblong in shape. The raw material gas inlet and the raw material gas outlet are connected to corresponding raw material gas pipelines.

[0035] In this embodiment, the electrode body is a square plate made of stainless steel or titanium alloy, which has the characteristics of high mechanical strength, good metal ductility, electrical and thermal conductivity, and high temperature resistance.

[0036] In this embodiment, fixing screw holes are provided at the four corners of the electrode plate body, and the fixing screw holes are used to install screws for fixed connection with other components.

[0037] In this embodiment, the interval between the two trapezoidal turbulences is reduced to two-thirds of the previous interval each time, and no trapezoidal turbulences are set at the inlet and outlet of the straight flow channel to ensure that the raw material gas enters and exits the straight flow channel without affecting it.

[0038] In one specific implementation of this embodiment, such as Figure 2As shown, the flow channel length is 50-300mm; the flow channel height is 1-4mm; the damping length is 1-5mm; the damping spacing is distributed in an arithmetic sequence, decreasing step by step; the damping height is 0.5-3mm; and the damping slope is 30-75℃.

[0039] The flow channel structure within the solid oxide fuel cell connector provided in this embodiment, by appropriately adding trapezoidal resistance within the straight flow channel, creates turbulence in the feed gas-liquid mixture, forcing the fluid towards the electrode and promoting improved reaction efficiency. The trapezoidal resistance is arranged in a pattern of initial sparseness followed by increased density, as shown in the flow channel diagram. Figure 1 As shown. Based on Bernoulli's equations of fluid dynamics, the law of conservation of mass, and the definition of Reynolds coefficient, the reasoning is as follows:

[0040]

[0041] Bernoulli's equation of fluid dynamics states that for an ideal fluid in steady flow, the sum of the kinetic energy, potential energy, and pressure per unit volume of fluid at any point in the same flow tube is a constant.

[0042] P is the fluid pressure; ρ is the fluid density; v is the fluid velocity; g is the acceleration due to gravity; h is the fluid height.

[0043] Law of conservation of mass: m1 = m2

[0044] m is the mass of the fluid; m = ρAv; where A is the cross-sectional area of ​​the fluid per unit time; and v is the velocity of the fluid.

[0045] ρA1v1=ρA2v2

[0046]

[0047] r = the radius through which the fluid passes (the ideal channel is cylindrical).

[0048] Reynolds coefficient definition:

[0049] Re is the Reynolds coefficient: a dimensionless number used to characterize fluid flow, proposed by British physicist Osborne Reynolds.

[0050] ρ is the density of the fluid, v is the velocity of the fluid, d is a characteristic length (such as the diameter of a pipe), and μ is the dynamic viscosity of the fluid.

[0051]

[0052] Therefore, given a constant initial velocity and viscous force, a narrower channel will result in a quadratic increase in flow velocity, leading to a multiplicative increase in the Reynolds number. If the channel width is reduced to half, the velocity will become four times its original value, and the Reynolds number will become twice its original value. Thus, under the same conditions, a trapezoidal resistance channel will provide a higher Reynolds number. At this point, the influence of inertial forces on the flow field is greater than that of viscous forces, resulting in less stable fluid flow. Small changes in velocity are easily developed and amplified, forming a turbulent and irregular flow field. Turbulence can enhance transport and reaction processes.

[0053] As the reaction proceeds, the raw materials are continuously consumed, and their density decreases. Therefore, more turbulence is needed to promote the reaction. Thus, a trapezoidal resistance structure with a lower density at the beginning and a higher density at the end is designed in the flow channel. This creates irregular turbulence with a continuously increasing Reynolds number, avoiding the drawbacks of traditional straight-flow channels such as poor venting and insufficient raw material reaction.

[0054] In one specific embodiment of this invention, the connector is manufactured as follows: a 4mm thick 430 stainless steel plate is machined into a 150mm wide square. Then, a resistance flow channel is machined in the core area of ​​the central flow channel, with a channel width of 3mm, a depth of 2mm, and a trapezoidal resistance height of 1mm. The corresponding air inlets, fixing screw holes, and other drilling requirements are then processed to finally form the stainless steel metal connector required for solid oxide fuel cells and electrolyzers. This connector is also applicable to PEM fuel cells / electrolyzers.

[0055] Example 2

[0056] In a typical embodiment of the present invention, a battery cell is provided, comprising a first electrode body, a composite cell, and a second electrode body arranged sequentially. The first electrode body and the second electrode body have the same structure and both adopt the solid oxide fuel cell connector as in Example 1. The straight flow channels of the first electrode body and the straight flow channels of the second electrode body are arranged perpendicular to each other.

[0057] Furthermore, the first electrode body, the composite cell, and the second electrode body are fixed together by screws, and the first electrode body and the composite cell, as well as the composite cell and the second electrode body, are sealed together using sealing insulating material.

[0058] In one specific embodiment of this example, the first electrode plate body serves as the anode plate, and the anode raw material gas flows in through the left side of the flow channel and exits from the right side; the second electrode plate body serves as the cathode plate, and the cathode raw material gas flows in and out in a direction perpendicular to the anode raw material gas.

[0059] For details, please refer to Figures 3 to 5As shown, a fuel flow channel 13 is provided inside the first electrode body 9, and an air flow channel 14 is provided inside the second electrode body 12. The fuel flow channel 13 and the air flow channel 14 are arranged perpendicularly. A membrane electrode 10 is provided between the fuel flow channel 13 and the air flow channel 14. The first electrode body 9 and the membrane electrode 10, as well as the membrane electrode 10 and the second electrode body 12, are sealed and connected by a sealing gasket 11 and fixed by a screw passing through the fixing screw hole 2. Thus, a fuel gas inlet 4 and a fuel gas outlet 1 are formed between the fuel flow channel 13 and the sealing gasket 11, and an air inlet 5 and an air outlet 3 are formed between the air flow channel 14 and the sealing gasket 11.

[0060] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A solid oxide fuel cell connector, characterized in that, The device includes an electrode body, on which a resistance flow channel region is provided. Parallel straight flow channels are evenly distributed within the resistance flow channel region. Multiple trapezoidal turbulent fluids are provided within each straight flow channel. The interval between two adjacent trapezoidal turbulent fluids decreases sequentially along the flow direction of the raw gas, so that the multiple trapezoidal turbulent fluids are distributed in the flow channel in a manner that is first sparse and then dense.

2. The solid oxide fuel cell connector as described in claim 1, characterized in that, The width of the trapezoidal turbulence is equal to the width of the straight flow channel, and the height of the trapezoidal turbulence is less than the height of the straight flow channel.

3. The solid oxide fuel cell connector as described in claim 1, characterized in that, The surface of the electrode body is provided with a groove, and the resistance flow channel area is located in the groove.

4. The solid oxide fuel cell connector as described in claim 3, characterized in that, The groove is also provided with a raw material gas inlet and a raw material gas outlet, which are located at both ends of the resistance flow channel area.

5. The solid oxide fuel cell connector as described in claim 4, characterized in that, Both the raw gas inlet and the raw gas outlet are oblong in shape.

6. The solid oxide fuel cell connector as described in claim 1, characterized in that, The electrode body is a square plate made of stainless steel or titanium alloy.

7. The solid oxide fuel cell connector as described in claim 6, characterized in that, The electrode plate body has fixing screw holes at its four corners.

8. The solid oxide fuel cell connector as described in claim 1, characterized in that, The interval between the two trapezoidal turbulent fluids is reduced to two-thirds of the previous interval each time, and no trapezoidal turbulent fluids are provided at the inlet and outlet of the straight flow channel.

9. A single battery cell, characterized in that, The battery includes a first electrode body, a composite cell, and a second electrode body arranged in sequence. The first electrode body and the second electrode body have the same structure and both adopt the solid oxide fuel cell connector as described in any one of claims 1-8. The straight flow channels of the first electrode body and the straight flow channels of the second electrode body are arranged perpendicular to each other.

10. The battery cell as described in claim 9, characterized in that, The first electrode body, the composite cell, and the second electrode body are fixed by screws. The first electrode body and the composite cell, as well as the composite cell and the second electrode body, are sealed and connected by sealing insulating material.

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