A dendritic solid oxide fuel cell bipolar plate structure

Abstract

The application discloses a dendritic solid oxide fuel cell bipolar plate structure, which comprises anode plates and cathode plates with the same structure arranged in a stack mode, wherein the anode plates and the cathode plates each comprise a plate body; two groups of symmetrical gas inlet channels and two groups of symmetrical gas outlet channels are arranged at both ends of the plate body respectively, and each group of the gas inlet channels and the gas outlet channels is provided with a plurality of channels; a plurality of gas flow channels are arranged at the middle part of the plate body; a plurality of rows of dendritic baffles are arranged between the gas inlet channels and the gas flow channels and between the gas outlet channels and the gas flow channels, and adjacent two rows of the baffles are arranged in a staggered mode. The bipolar plate structure provided by the application is provided with the staggered dendritic baffles arranged between the gas inlet channels and the gas flow channels and between the gas outlet channels and the gas flow channels, so that the gas can flow and diffuse more easily in the plate, the uniform distribution of the reaction gas is facilitated, the problem of uneven heat distribution in the cell is improved, and the service life is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid oxide fuel cells, in particular to a dendritic solid oxide fuel cell bipolar plate structure. BACKGROUND

[0002] With the increasing demand for energy and the increasingly serious environmental problems, fuel cells, as a kind of efficient and clean energy conversion device, have attracted widespread attention. Solid oxide fuel cell (SOFC) is a kind of power generation device that directly converts the chemical energy of fuel and oxidant into electrical energy at medium-high temperature, which has the advantages of high efficiency, cleanliness, high power generation efficiency and good flexibility of fuel, and is considered as an important development direction in the future energy field. However, there are still many problems in the practical application of solid oxide fuel cells, one of which is how to improve the uniformity of fluid distribution in the cell. The fluid flow rate in the flow channel near the gas inlet and outlet of the traditional bipolar plate structure is faster, and the fluid flow rate in other areas is slower, resulting in uneven fluid distribution, which leads to problems such as performance degradation and short service life of the cell, limiting the large-scale commercial application of solid oxide fuel cells.

[0003] At present, in order to improve the fluid distribution in the solid oxide fuel cell, methods such as increasing the number of inlet and outlet manifolds and setting serpentine flow channels are usually used. However, these methods have high cost in processing and manufacturing, and cannot greatly improve the uniformity of fluid distribution in the cell. SUMMARY

[0004] To solve the above technical problems, the present application provides a dendritic solid oxide fuel cell bipolar plate structure, which sets up staggered distribution of dendritic baffles, so that the gas can flow and diffuse more easily inside the plate, which is beneficial to the uniform distribution of reaction gas, improves the problem of uneven heat distribution in the cell, and increases the service life.

[0005] The technical scheme adopted by the present application is:

[0006] The present application provides a dendritic solid oxide fuel cell bipolar plate structure, which includes anode plates and cathode plates with the same structure stacked and arranged, and the anode plates and cathode plates each include a plate body.

[0007] The plate body is provided with a gas inlet area and a gas outlet area at both ends, respectively, and the gas inlet area and the gas outlet area are respectively provided with two groups of gas inlets composed of a plurality of gas inlet rib plates and two groups of gas outlets composed of a plurality of gas outlet rib plates, and the two groups of gas inlets and the two groups of gas outlets are symmetric about the longitudinal center line of the plate body, and the two groups of gas inlets and the two groups of gas outlets are symmetric about the transverse center line of the plate body; the adjacent two gas inlet rib plates of each group of gas inlets form a gas inlet channel, and the adjacent two gas outlet rib plates of each group of gas outlets form a gas outlet channel;

[0008] A reaction area is provided in the middle of the plate body and between the air inlet area and the exhaust area. The reaction area is connected to the air inlet area and the exhaust area. The reaction area is provided with a plurality of mutually parallel flow channel ribs, and a gas flow channel is formed between two adjacent flow channel ribs.

[0009] Several rows of dendritic baffles are arranged between the air inlet channel and the gas flow channel, and between the air exhaust channel and the gas flow channel, and two adjacent rows of baffles are arranged in a staggered manner.

[0010] Furthermore, the air intake ribs and exhaust ribs located on the innermost side are rectangular and perpendicular to the flow channel ribs, and the remaining air intake ribs and exhaust ribs are L-shaped, and the long sides of the L-shaped ribs are perpendicular to the flow channel ribs, the short sides of the L-shaped ribs are bent toward the flow channel ribs, and the length of the long sides of the L-shaped ribs decreases from the end surface of the plate body to the middle.

[0011] Furthermore, two ends of the two flow channel ribs located on the outermost side of the plate body extend toward two ends of the plate body respectively, and the extended ends are butted against the air intake rib and the exhaust rib located on the innermost side.

[0012] Furthermore, a trapezoidal area is formed between the air intake ribs and the flow channel ribs, and between the exhaust ribs and the flow channel ribs. The branch-shaped baffles are arranged in the trapezoidal area, and the number of branch-shaped baffles in each row increases from the end surface of the plate body to the middle.

[0013] Furthermore, the baffle is in an inverted Y shape, and the opening side of the Y-shaped baffle faces the gas flow channel.

[0014] Furthermore, the opening side angle of the Y-shaped baffle is 45-90 degrees, the distance between two adjacent baffles in the same row is 2-4 mm, and the distance between two adjacent rows of baffles is 2-4 mm.

[0015] Furthermore, the width of the gas flow channel is 1 to 3 mm.

[0016] Furthermore, the distance between the long sides of two adjacent intake ribs and the distance between the long sides of two adjacent exhaust ribs are both 0.5-1.5 mm, and the distance between the short sides of two adjacent intake ribs and the distance between the short sides of two adjacent exhaust ribs are both 1-2 mm.

[0017] Furthermore, the distance between the end of the flow channel rib and the innermost dendritic baffle is 1 to 3 mm.

[0018] The beneficial effects of the present invention are:

[0019] (1) The present invention provides a dendritic solid oxide fuel cell bipolar plate structure. By providing staggered dendritic baffles between the air inlet channel and the gas flow channel, and between the exhaust channel and the gas flow channel, the gas is more easily flowed and diffused within the plate, which is conducive to the uniform distribution of the reaction gas, improves the problem of uneven heat distribution within the battery, and enhances its service life.

[0020] (2) The present invention provides a dendritic solid oxide fuel cell bipolar plate structure, wherein the air inlet and the air outlet are provided with a plurality of inlet / exhaust ribs, which can separate the inlet / exhaust ports to form a plurality of inlet / exhaust channels, so that the gas can enter and exhaust uniformly, and further the reaction gas is evenly distributed inside the flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 Schematic diagram of the structure of a monopolar plate according to an embodiment of the present invention;

[0023] Figure 2 for Figure 1 A magnified view of the structure at center A;

[0024] Figure 3 for Figure 1 A magnified view of the structure at point B in the middle;

[0025] Figure 4 Velocity cloud diagrams of the gas flow channels of the embodiment and the comparative example;

[0026] Figure 5 Graphs showing the central velocity points of the gas flow channels of the embodiment and the comparative example.

[0027] Markings in the figure: 1. Intake rib; 2. Exhaust rib; 3. Intake channel; 4. Exhaust channel; 5. Flow channel rib; 6. Gas flow channel; 7. Baffle. DETAILED DESCRIPTION

[0028] The present invention provides a dendritic solid oxide fuel cell bipolar plate structure. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0029] The present invention will be described in detail below with reference to the accompanying drawings.

[0030] Example

[0031] Reference Figure 1-3 This embodiment provides a dendritic solid oxide fuel cell bipolar plate structure, including a stacked anode plate and a cathode plate having the same structure. The specific structure is described using the anode plate (i.e., monopolar plate) as an example.

[0032] The anode plate includes a plate body, with an air intake area and an exhaust area respectively provided at both ends of the plate body, wherein the air intake area and the exhaust area are respectively provided with two groups of air intake ports and two groups of exhaust ports, the two groups of air intake ports and the two groups of exhaust ports being symmetrical about the longitudinal center line of the plate body, and the two groups of air intake ports and the two groups of exhaust ports being symmetrical about the transverse center line of the plate body; each group of air intake ports includes six air intake ribs, and each group of exhaust ports includes six exhaust ribs, and an air intake channel 3 is formed between two adjacent air intake ribs of each group of air intake ports, forming five air intake channels in each group, and an exhaust channel 4 is formed between two adjacent exhaust ribs of each group of exhaust ports, forming five exhaust channels in each group;

[0033] A reaction area is provided in the middle of the plate body and between the air inlet area and the exhaust area. The reaction area is connected to the air inlet area and the exhaust area. The reaction area is provided with a plurality of mutually parallel flow channel ribs 5, and a gas flow channel 6 is formed between two adjacent flow channel ribs.

[0034] Several rows of dendritic baffles 7 are provided between the air inlet channel 3 and the gas flow channel 6 and between the air exhaust channel 4 and the gas flow channel 6 , and two adjacent rows of baffles 7 are arranged in a staggered manner.

[0035] Specifically, the air intake ribs 1 and exhaust ribs 2 located on the innermost side are rectangular and perpendicular to the flow channel ribs 5, and are connected to the extended ends of the two flow channel ribs 5 located on the outermost side of the plate body extending to both ends of the plate body; while the remaining air intake ribs 1 and exhaust ribs 2 are L-shaped, and the long sides of the L-shaped ribs are perpendicular to the flow channel ribs 5, and the short sides of the L-shaped ribs are bent toward the gas flow channel ribs, and the length of the long sides of the L-shaped ribs decreases from the end surface of the plate body to the middle, and the length of the innermost air intake ribs 1 and exhaust ribs 2 is also shorter than the length of the long sides of the L-shaped ribs adjacent to them.

[0036] Since the lengths of the above-mentioned intake ribs 1 and exhaust ribs 2 gradually decrease from the end surface of the plate body to the middle, a trapezoidal area is formed between the intake ribs 1 and the flow channel ribs 5, and between the exhaust ribs 2 and the flow channel ribs 5. The above-mentioned branch-shaped baffles 7 are arranged in the trapezoidal area, and the number of branch-shaped baffles 7 in each row increases sequentially from the end surface of the plate body to the middle.

[0037] To ensure uniform gas distribution, when the above-mentioned branch-shaped baffles are arranged in a trapezoidal area, no baffles are set in the air intake channel or exhaust channel near the end of the plate body, and a row of baffles are respectively arranged in the remaining air intake channels and exhaust channels, and between the short sides of the two symmetrically arranged air intake ribs and between the short sides of the two exhaust ribs, and the outermost baffle of each row of baffles is located in the middle of the opening of the air intake channel or exhaust channel close to the short side of the air intake rib or exhaust rib; in addition, at least one row of baffles is also set between the innermost air intake / exhaust rib and the two ends of the flow channel rib, and the distance between the end of the flow channel rib and the innermost branch-shaped baffle is 2 mm.

[0038] Specifically, the overall dimensions of the anode plate are 73 mm × 34 mm × 3 mm. The spacing L4 between the long sides of two adjacent intake ribs and the long sides of two adjacent exhaust ribs are both 1.0 mm. The length of the first-stage intake ribs and exhaust ribs near the end of the plate body is 16.0 mm. Except for the length difference L3 between the first-stage intake / exhaust ribs and the second-stage intake / exhaust ribs, which is 1.0 mm, the length difference L5 between the other two adjacent intake / exhaust ribs is 2.0 mm. That is, the length of the adjacent intake / exhaust ribs is 1.0 mm. The spacing between the short sides of the ribs is 2.0 mm; the above-mentioned flow channel ribs are rectangular with dimensions of 38 mm × 1 mm × 2 mm, and the width of the gas flow channel formed between two adjacent flow channel ribs is 2.0 mm; the above-mentioned dendritic baffles are specifically in an inverted Y shape, and the opening sides of the Y-shaped baffles in the air intake area and the exhaust area are both facing the gas flow channel, the opening angle of the Y-shaped baffle is 60°, the distance L1 between two adjacent baffles in the same row is 2.0 mm, and the distance L2 between two adjacent rows of baffles is 2.0 mm.

[0039] Comparative Example

[0040] The difference between this comparative example and the embodiment is that in this comparative example, one air inlet is provided in the air inlet region, two exhaust ports are provided in the exhaust region, no dendritic baffle is provided, and the flow channel ribs and gas flow channels in the reaction region are the same as those in the embodiment.

[0041] In this comparative example, the air inlet is located in the middle of one end of the plate body and has a size of 11mm×7mm; the two exhaust ports are symmetrically located at the other end of the plate body; the distance between the flow channel rib and the air inlet and exhaust ports is the same as the distance between the flow channel rib and the innermost baffle in the embodiment.

[0042] The performance comparison of the bipolar plate structures of the above embodiment and the comparative example is carried out as follows:

[0043] (1) Establish a monopolar plate geometric model in Solidworks modeling software based on the bipolar plate structural dimensions;

[0044] (2) Importing the monopole plate geometric model established in step (1) into Comsol and determining the boundary conditions involved in the geometric model;

[0045] (3) Set the material parameters and simulation conditions in Comsol, perform simulation calculations, and obtain the gas flow channel velocity cloud map and the velocity point map of each gas flow channel center.

[0046] The geometric models were established according to the embodiment and the comparative example respectively, and simulation calculations were performed, and the simulation results of the two were compared. Figure 4 and Figure 5 As shown. Figure 4 Shown are velocity cloud diagrams of the gas flow channels of the embodiment and the comparative example, wherein: Figure 4 (a) is the velocity cloud diagram of the embodiment structure, and (b) is the velocity cloud diagram of the comparative structure. Figure 4 It can be seen from the figure that before the structural optimization, the gas mainly flows through the gas flow channels near the air inlet and exhaust ports. The unreasonable design leads to uneven fluid distribution. After the structural optimization, the gas flowing into each gas flow channel is redistributed due to the presence of the air inlet / exhaust ribs and the dendritic baffles, making the fluid distribution more uniform. Figure 5 Shown are the center velocity point diagrams of each gas flow channel of the embodiment and the comparative example, Figure 5 (a) is the center velocity point diagram of the embodiment structure, and (b) is the center velocity point diagram of the comparative structure. Figure 5 It can be seen that before the structural optimization, the range of the central velocity of each gas flow channel was about 0.4m / s, and the flow velocity in some gas flow channels was close to 0; after the structural optimization, the range of the central velocity of each gas flow channel was about 0.15m / s, a decrease of 62.5%, and the problem of the flow velocity in some gas flow channels being close to 0 was improved, thereby improving the uniformity of the fluid distribution in the bipolar plate.

[0047] It should be noted that the parts not described in the present invention can be implemented by adopting or drawing on existing technologies.

[0048] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A dendritic solid oxide fuel cell bipolar plate structure comprising a stacked anode plate and a cathode plate having the same structure, characterized in that: The anode plate and the cathode plate both include a plate body; Both ends of the plate are respectively provided with an air intake area and an exhaust area, and the air intake area and the exhaust area are respectively provided with two groups of air intakes consisting of a plurality of air intake ribs and two groups of exhausts consisting of a plurality of exhaust ribs. The two groups of air intakes and the two groups of exhausts are symmetrical about the longitudinal center line of the plate, and the two groups of air intakes and the two groups of exhausts are symmetrical about the transverse center line of the plate; an air intake channel is formed between two adjacent air intake ribs of each group of air intakes, and an exhaust channel is formed between two adjacent exhaust ribs of each group of air intakes; A reaction area is provided in the middle of the plate body and between the air inlet area and the exhaust area. The reaction area is connected to the air inlet area and the exhaust area. The reaction area is provided with a plurality of mutually parallel flow channel ribs, and a gas flow channel is formed between two adjacent flow channel ribs. Several rows of dendritic baffles are arranged between the air inlet channel and the gas flow channel, and between the air exhaust channel and the gas flow channel, and two adjacent rows of baffles are arranged in a staggered manner.

2. The dendritic solid oxide fuel cell bipolar plate structure according to claim 1, characterized in that: The innermost intake ribs and exhaust ribs are rectangular and perpendicular to the flow channel ribs, while the remaining intake ribs and exhaust ribs are L-shaped, with the long sides of the L-shaped ribs perpendicular to the flow channel ribs, and the short sides of the L-shaped ribs are bent toward the flow channel ribs. The length of the long sides of the L-shaped ribs decreases from the end surface of the plate body to the middle.

3. The dendritic solid oxide fuel cell bipolar plate structure according to claim 2, characterized in that: The two flow channel ribs located on the outermost side of the plate body have two ends extending toward the two ends of the plate body respectively, and the extended ends are butted against the air intake rib and the exhaust rib located on the innermost side.

4. The dendritic solid oxide fuel cell bipolar plate structure according to claim 3, characterized in that: A trapezoidal area is formed between the air intake ribs and the flow channel ribs, and between the exhaust ribs and the flow channel ribs. The branch-shaped baffles are arranged in the trapezoidal area, and the number of the branch-shaped baffles in each row increases from the end surface of the plate body to the middle.

5. The dendritic solid oxide fuel cell bipolar plate structure according to claim 1, characterized in that: The baffle is in an inverted Y shape, and the opening side of the Y-shaped baffle faces the gas flow channel.

6. The dendritic solid oxide fuel cell bipolar plate structure according to claim 5, characterized in that: The opening side angle of the Y-shaped baffle is 45-90 degrees, the distance between two adjacent baffles in the same row is 2-4 mm, and the distance between two adjacent rows of baffles is 2-4 mm.

7. The dendritic solid oxide fuel cell bipolar plate structure according to claim 1, characterized in that: The width of the gas flow channel is 1 to 3 mm.

8. The dendritic solid oxide fuel cell bipolar plate structure according to claim 2, characterized in that: The distance between the long sides of two adjacent intake ribs and the long sides of two adjacent exhaust ribs are both 0.5-1.5 mm, and the distance between the short sides of two adjacent intake ribs and the short sides of two adjacent exhaust ribs are 1-2 mm.

9. The dendritic solid oxide fuel cell bipolar plate structure according to claim 1, characterized in that: The distance between the end of the flow channel rib and the innermost dendritic baffle is 1 to 3 mm.

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