A fuel cell stack based on a bionic bipolar plate flow field structure

Abstract

The present invention relates to the field of fuel cell technology, specifically to a fuel cell stack based on a bionic bipolar plate flow field structure, including a bionic bipolar plate, the bionic bipolar plate is formed by laminating and bonding an anode plate and a cathode plate, a hydrogen flow channel is provided on the upper surface of the anode plate, the hydrogen flow channel includes a first rectangular inlet, a first Archimedean spiral channel, a first rectangular interface, a second Archimedean spiral channel and a first rectangular outlet, and an air flow channel is provided on the lower surface of the cathode plate, the air flow channel includes a second rectangular inlet, a third Archimedean spiral channel, a second rectangular interface, a fourth Archimedean spiral channel and a second rectangular outlet. The present invention designs hydrogen flow channels and air flow channels based on bionics, and when the gas flows in the hydrogen flow channels and the air flow channels, it will advance along the Archimedean spiral channel, the pressure loss is small, the heat exchange is uniform, the mass transfer efficiency is enhanced, and the performance and stability of the fuel cell are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell stack based on a bionic bipolar plate flow field structure. Background Art

[0002] Fuel cell bipolar plates play a variety of important roles, including distributing reaction gases, collecting current, draining water, conducting heat, and providing mechanical support. The flow field structure of the bipolar plate determines the effective reaction area ratio, the uniformity of reaction gas distribution, etc., and significantly affects multiple important parameters such as fuel cell power, current density distribution within the plate range, and voltage consistency between the plates, thereby determining the fuel cell's operating performance indicators and service life, and is an important part of fuel cell structural design.

[0003] A Chinese invention with publication number CN109935852B discloses a leaf vein-shaped interdigitated fuel cell flow field structure, a fuel cell bipolar plate and a fuel cell. In the invention, the fuel cell bipolar plate adopts a design that imitates leaf veins, which increases the forced convection of the gas. However, most of the corners of the gas flow channel are rectangular or irregular structures, which will produce local pressure drops and lead to large pressure drops at the inlet and outlet. Summary of the invention

[0004] The purpose of the present invention is to provide a fuel cell stack based on a bionic bipolar plate flow field structure to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: a fuel cell stack based on a bionic bipolar plate flow field structure, wherein the fuel cell stack is formed by stacking a plurality of single cells in series, wherein the single cells are formed by alternately stacking a bionic bipolar plate and a membrane electrode, wherein the bionic bipolar plate is formed by stacking and bonding an anode plate and a cathode plate, wherein a hydrogen flow channel is provided on the upper surface of the anode plate, wherein the hydrogen flow channel comprises a first rectangular inlet, a first Archimedean spiral channel, a first rectangular interface, a second Archimedean spiral channel connected in sequence along the hydrogen flow direction, The cathode plate has an Archimedean spiral channel and a first rectangular outlet, the radius of the first Archimedean spiral channel decreases along the flow direction of hydrogen, the radius of the second Archimedean spiral channel increases along the flow direction of hydrogen, an air flow channel is opened on the lower surface of the cathode plate, the air flow channel comprises a second rectangular inlet, a third Archimedean spiral channel, a second rectangular interface, a fourth Archimedean spiral channel and a second rectangular outlet which are sequentially connected along the flow direction of air, the radius of the third Archimedean spiral channel increases along the flow direction of hydrogen, the radius of the fourth Archimedean spiral channel decreases along the flow direction of hydrogen.

[0006] Optionally, the first Archimedean spiral and the second Archimedean spiral are arranged front-to-back symmetrically with respect to the first rectangular interface, and the third Archimedean spiral and the fourth Archimedean spiral are arranged front-to-back symmetrically with respect to the second rectangular interface.

[0007] Optionally, the first Archimedean spiral is integrally formed by a first arc segment connected to the first rectangular inlet and a second arc segment connected to the first rectangular interface, and the ratio of the radius of the first arc segment to the radius of the second arc segment is 3:2; the third Archimedean spiral is integrally formed by a second arc segment connected to the second rectangular inlet and a third arc segment connected to the second rectangular interface, and the ratio of the radius of the first arc segment to the radius of the second arc segment is 2:3.

[0008] Optionally, there are several first rectangular interfaces, and the several first rectangular interfaces are arranged at equal intervals in the left-right direction. Two ends of the first rectangular interface are respectively fixedly connected to two first Archimedean spiral tracks and two second Archimedean spiral tracks, and the two first Archimedean spiral tracks and the two second Archimedean spiral tracks are arranged symmetrically on the left and right. A cross channel is provided between the arc segments of two first Archimedean spiral tracks connected to the same first rectangular interface and close to the first rectangular interface, and two cross channels are provided between two first Archimedean spiral tracks adjacent to each other on the left and right and with opposite concave directions.

[0009] Optionally, there are several second rectangular interfaces, and the several second rectangular interfaces are arranged at equal intervals in the left-right direction. Two ends of the second rectangular interface are respectively fixedly connected to two third Archimedean spirals and two fourth Archimedean spirals, and the two third Archimedean spirals and the two fourth Archimedean spirals are arranged symmetrically on the left and right. A cross channel is provided between the arc segments of two third Archimedean spirals connected to the same second rectangular interface that are away from the second rectangular interface, and two cross channels are provided between two third Archimedean spirals that are adjacent to each other on the left and right and have opposite concave directions.

[0010] Optionally, the first rectangular outlet and the first rectangular interface are respectively tangent to two ends of the first Archimedean spiral, and the first rectangular interface and the first rectangular outlet are respectively tangent to two ends of the second Archimedean spiral.

[0011] Optionally, the second rectangular outlet and the second rectangular interface are respectively tangent to two ends of the third Archimedean spiral, and the second rectangular interface and the second rectangular outlet are respectively tangent to two ends of the fourth Archimedean spiral.

[0012] Optionally, the forward longitudinal section of the hydrogen flow channel and the forward longitudinal section of the air flow channel are both rectangular, the height of the hydrogen flow channel and the height of the air flow channel are equal, and the width of the hydrogen flow channel and the width of the air flow channel both obey the Universal Murray law.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The present invention designs the hydrogen flow channel and the air flow channel based on bionics. When the gas flows in the hydrogen flow channel and the air flow channel, it moves along the Archimedean spiral channel. The inner wall of the Archimedean spiral channel is smooth, and the pressure loss is small. The gas exchanges heat evenly in the Archimedean spiral channel, which enhances the mass transfer efficiency, thereby improving the performance and stability of the fuel cell;

[0015] 2. The present invention can improve the uniformity of gas distribution through the vertical staggered design of hydrogen flow channels and air flow channels, so that the gas can fully react chemically with the membrane electrode, improve the utilization efficiency of the membrane electrode, and help reduce gas short-circuiting and optimize drainage and heat transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the bionic bipolar plate in the present invention;

[0017] Figure 2 A top view of the bionic bipolar plate of the present invention;

[0018] Figure 3 This is a bottom view of the bionic bipolar plate of the present invention.

[0019] In the figure: 1. bionic bipolar plate; 2. anode plate; 3. cathode plate; 4. hydrogen flow channel; 401. first rectangular inlet; 402. first Archimedean spiral; 403. first rectangular interface; 404. second Archimedean spiral; 405. first rectangular outlet; 5. air flow channel; 501. second rectangular inlet; 502. third Archimedean spiral; 503. second rectangular interface; 504. fourth Archimedean spiral; 505. second rectangular outlet. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example: See Figures 1 to 3The present invention provides a fuel cell stack based on a bionic bipolar plate flow field structure. The fuel cell stack is formed by stacking a number of single cells in series. The single cells are formed by alternately stacking a bionic bipolar plate 1 and a membrane electrode. The bionic bipolar plate 1 is formed by stacking and bonding an anode plate 2 and a cathode plate 3. A hydrogen flow channel 4 is provided on the upper surface of the anode plate 2, and an air flow channel 5 is provided on the lower surface of the cathode plate 3.

[0022] In addition to the above embodiments, in this embodiment, the forward longitudinal section of the hydrogen flow channel 4 and the forward longitudinal section of the air flow channel 5 are both rectangular, the height of the hydrogen flow channel 4 and the height of the air flow channel 5 are equal, and the width of the hydrogen flow channel 4 and the width of the air flow channel 5 both obey the Universal Murray law.

[0023] See also Figure 2 The hydrogen flow channel 4 includes a first rectangular inlet 401, a first Archimedean spiral 402, a first rectangular interface 403, a second Archimedean spiral 404 and a first rectangular outlet 405 which are sequentially connected along the flow direction of hydrogen. The radius of the first Archimedean spiral 402 decreases along the flow direction of hydrogen, and the radius of the second Archimedean spiral 404 increases along the flow direction of hydrogen. The first Archimedean spiral 402 is integrally formed by a first arc segment connected to the first rectangular inlet 401 and a second arc segment connected to the first rectangular interface 403, and the ratio of the radius of the first arc segment to the radius of the second arc segment is 3:2.

[0024] In the above embodiment, the first rectangular outlet 405 and the first rectangular interface 403 are tangent to the two ends of the first Archimedean spiral 402 , respectively, and the first rectangular interface 403 and the first rectangular outlet 405 are tangent to the two ends of the second Archimedean spiral 404 , respectively. The first Archimedean spiral track 402 and the second Archimedean spiral track 404 are symmetrically arranged about the first rectangular interface 403. There are a plurality of first rectangular interfaces 403, and the plurality of first rectangular interfaces 403 are arranged at equal intervals along the left-right direction. Two ends of the first rectangular interface 403 are respectively fixedly connected to two first Archimedean spiral tracks 402 and two second Archimedean spiral tracks 404. The two first Archimedean spiral tracks 402 and the two second Archimedean spiral tracks 404 are both symmetrically arranged. A cross channel is provided between the arc segments of two first Archimedean spiral tracks 402 connected to the same first rectangular interface 403 and close to the first rectangular interface 403, and two cross channels are provided between two first Archimedean spiral tracks 402 adjacent to each other on the left and right and having opposite concave directions.

[0025] See also Figure 3The air flow channel 5 includes a second rectangular inlet 501, a third Archimedean spiral 502, a second rectangular interface 503, a fourth Archimedean spiral 504 and a second rectangular outlet 505 which are sequentially connected along the air flow direction. The radius of the third Archimedean spiral 502 increases along the hydrogen flow direction, and the fourth Archimedean spiral 504 decreases along the hydrogen flow direction. The third Archimedean spiral 502 is formed integrally by a second arc segment connected to the second rectangular inlet 501 and a third arc segment connected to the second rectangular interface 503, and the ratio of the radius of the first arc segment to the radius of the second arc segment is 2:3.

[0026] In the above embodiment, the second rectangular outlet 505 and the second rectangular interface 503 are tangent to the two ends of the third Archimedean spiral 502 , respectively, and the second rectangular interface 503 and the second rectangular outlet 505 are tangent to the two ends of the fourth Archimedean spiral 504 , respectively. The third Archimedean spiral track 502 and the fourth Archimedean spiral track 504 are symmetrically arranged with respect to the second rectangular interface 503. There are a plurality of second rectangular interfaces 503, and the plurality of second rectangular interfaces 503 are arranged at equal intervals in the left-right direction. Two third Archimedean spiral tracks 502 and two fourth Archimedean spiral tracks 504 are fixedly connected at both ends of the second rectangular interface 503, respectively. The two third Archimedean spiral tracks 502 and the two fourth Archimedean spiral tracks 504 are both symmetrically arranged. A cross channel is provided between the arc segments of two third Archimedean spiral tracks 502 connected to the same second rectangular interface 503 that are away from the second rectangular interface 503, and two cross channels are provided between two third Archimedean spiral tracks 502 that are adjacent to each other on the left and right and have opposite concave directions.

[0027] The present invention designs the hydrogen flow channel 4 and the air flow channel 5 based on bionics. When the hydrogen flow channel 4 and the air flow channel 5 flow, the gas will advance along the Archimedean spiral path. The inner wall of the Archimedean spiral path is smooth, and the pressure loss is small. The Archimedean spiral has isometry, that is, the distance between any pole diameter and the intersection of two adjacent circles is constant. This isometry makes the gas heat exchange more uniform, enhances the mass transfer efficiency, and thus improves the performance and stability of the fuel cell. The present invention can also improve the uniformity of gas distribution through the upper and lower misalignment design of the hydrogen flow channel 4 and the air flow channel 5, so that the gas fully reacts with the membrane electrode, improves the utilization efficiency of the membrane electrode, and can help reduce the gas short circuit phenomenon, optimize drainage and heat transfer. In addition, when the hydrogen flow channel 4 and the air flow channel 5 flow, the gas will advance along the Archimedean spiral path to perform centrifugal motion, and water can be separated from the gas according to the different specific gravities of the gas and water.

[0028] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fuel cell stack based on a bionic bipolar plate flow field structure, wherein the fuel cell stack is formed by stacking a plurality of single cells in series, wherein the single cells are formed by alternately stacking a bionic bipolar plate (1) and a membrane electrode in sequence, and wherein: The bionic bipolar plate (1) is formed by laminating and bonding an anode plate (2) and a cathode plate (3); a hydrogen flow channel (4) is provided on the upper surface of the anode plate (2); the hydrogen flow channel (4) comprises a first rectangular inlet (401), a first Archimedean spiral channel (402), a first rectangular interface (403), a second Archimedean spiral channel (404) and a first rectangular outlet (405) which are sequentially connected along the flow direction of hydrogen; the radius of the first Archimedean spiral channel (402) decreases along the flow direction of hydrogen; and the radius of the second Archimedean spiral channel (404) decreases along the flow direction of hydrogen. The air flow channel (404) increases along the flow direction of hydrogen, the lower surface of the cathode plate (3) is provided with an air flow channel (5), the air flow channel (5) comprises a second rectangular inlet (501), a third Archimedean spiral channel (502), a second rectangular interface (503), a fourth Archimedean spiral channel (504) and a second rectangular outlet (505) which are sequentially connected along the flow direction of air, the radius of the third Archimedean spiral channel (502) increases along the flow direction of hydrogen, and the radius of the fourth Archimedean spiral channel (504) decreases along the flow direction of hydrogen.

2. A fuel cell stack based on a bionic bipolar plate flow field structure according to claim 1, characterized in that: The first Archimedean spiral track (402) and the second Archimedean spiral track (404) are arranged front-to-back symmetrically with respect to the first rectangular interface (403), and the third Archimedean spiral track (502) and the fourth Archimedean spiral track (504) are arranged front-to-back symmetrically with respect to the second rectangular interface (503).

3. A fuel cell stack based on a bionic bipolar plate flow field structure according to claim 2, characterized in that: The first Archimedean spiral track (402) is formed integrally by a first arc segment connected to the first rectangular inlet (401) and a second arc segment connected to the first rectangular interface (403), and the ratio of the radius of the first arc segment to the radius of the second arc segment is 3:

2. The third Archimedean spiral track (502) is formed integrally by a second arc segment connected to the second rectangular inlet (501) and a third arc segment connected to the second rectangular interface (503), and the ratio of the radius of the first arc segment to the radius of the second arc segment is 2:

3.

4. A fuel cell stack based on a bionic bipolar plate flow field structure according to claim 3, characterized in that: A plurality of the first rectangular interfaces (403) are provided, and the plurality of the first rectangular interfaces (403) are arranged at equal intervals in the left-right direction; two first Archimedean spiral tracks (402) and two second Archimedean spiral tracks (404) are respectively fixedly connected at two ends of the first rectangular interface (403); the two first Archimedean spiral tracks (402) and the two second Archimedean spiral tracks (404) are arranged symmetrically on the left and right; a cross channel is provided between arc sections of two first Archimedean spiral tracks (402) connected to the same first rectangular interface (403) close to the first rectangular interface (403); and two cross channels are provided between two first Archimedean spiral tracks (402) adjacent to each other on the left and right and having opposite concave directions.

5. A fuel cell stack based on a bionic bipolar plate flow field structure according to claim 4, characterized in that: A plurality of the second rectangular interfaces (503) are provided, and the plurality of the second rectangular interfaces (503) are arranged at equal intervals in the left-right direction; two ends of the second rectangular interface (503) are respectively fixedly connected to two third Archimedean spirals (502) and two fourth Archimedean spirals (504); the two third Archimedean spirals (502) and the two fourth Archimedean spirals (504) are arranged symmetrically on the left and right; a cross channel is provided between arc sections of two third Archimedean spirals (502) connected to the same second rectangular interface (503) that are away from the second rectangular interface (503); and two cross channels are provided between two third Archimedean spirals (502) that are adjacent on the left and right and have opposite concave directions.

6. The fuel cell stack based on the bionic bipolar plate flow field structure according to claim 3, characterized in that: The first rectangular outlet (405) and the first rectangular interface (403) are respectively tangent to two ends of the first Archimedean spiral (402), and the first rectangular interface (403) and the first rectangular outlet (405) are respectively tangent to two ends of the second Archimedean spiral (404).

7. A fuel cell stack based on a bionic bipolar plate flow field structure according to claim 6, characterized in that: The second rectangular outlet (505) and the second rectangular interface (503) are respectively tangent to two ends of the third Archimedean spiral (502), and the second rectangular interface (503) and the second rectangular outlet (505) are respectively tangent to two ends of the fourth Archimedean spiral (504).

8. The fuel cell stack based on the bionic bipolar plate flow field structure according to claim 1, characterized in that: The forward longitudinal section of the hydrogen flow channel (4) and the forward longitudinal section of the air flow channel (5) are both rectangular, the height of the hydrogen flow channel (4) and the height of the air flow channel (5) are equal, and the width of the hydrogen flow channel (4) and the width of the air flow channel (5) both obey the Universal Murray law.

Images