A graphite bipolar plate and proton exchange membrane fuel cell

Abstract

This invention discloses a graphite bipolar plate and a proton exchange membrane fuel cell, comprising a plate body; cooling flow channels are arranged on the surface of the plate body, the inlet of the cooling flow channels is connected to the refrigerant inlet, and the outlet of the cooling flow channels is connected to the refrigerant outlet; wherein, the cooling flow channels are divided into a first flow channel region, a second flow channel region, and a third flow channel region from top to bottom; a first flow channel cluster arranged in a serpentine pattern is arranged along the long side of the plate body in the first flow channel region, a second flow channel cluster arranged in a serpentine pattern is arranged along the long side of the plate body in the second flow channel region, and a third flow channel cluster arranged in a serpentine pattern is arranged along the long side of the plate body in the third flow channel region; this invention effectively reduces the overall local pressure drop loss; at the same time, it avoids the phenomenon of monotonous temperature increase from the refrigerant inlet to the refrigerant outlet, which can effectively improve the temperature distribution uniformity, thereby ensuring the performance and lifespan of the fuel cell.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and specifically relates to a graphite bipolar plate and proton exchange membrane fuel cell. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is an energy conversion device that converts chemical energy into electrical energy. It has advantages such as high efficiency, high power density, fast start-up speed, low operating temperature, and zero emissions, and is widely used in transportation and hydrogen energy storage. However, due to the limitation of conversion efficiency, PEMFC inevitably generates a large amount of heat during operation. According to the heat generation mechanism, different regions of the cell contain four types of heat sources: Joule heat, latent heat of phase change, entropy heat of electrochemical reaction, and irreversible heat. When these four heat sources cannot be discharged in time or the temperature distribution is uneven, local hot spots will be generated, which will lead to the degradation of the catalyst layer inside the fuel cell and perforation of the proton exchange membrane.

[0003] Currently, various cooling technologies have been applied to PEMFC stack cooling, such as phase change cooling and single-phase cooling. Phase change cooling is less commonly used in fuel cell stacks due to its complexity and high cost, while single-phase cooling is the mainstream solution in commercial fuel cell stacks. For low-power (below 5kW) fuel cell stacks, air cooling is commonly used; for high-power (100kW and above) fuel cell stacks, liquid cooling is typically employed, utilizing the refrigerant inside graphite or metal bipolar plates to remove the heat generated during stack operation. For each cell within the stack, the arrangement of the cooling channels plays a crucial role in ensuring the uniformity of the internal temperature distribution. Therefore, the goal of cooling channel design is to maximize temperature uniformity and minimize pressure drop while avoiding localized hot spots.

[0004] For metal bipolar plates, the gas flow field and cooling flow field on the plate are formed simultaneously during the stamping process, meaning the gas channel and refrigerant channel have the same type. The internal cooling flow field is then adjusted by inserting a baffle. However, for relatively thicker graphite bipolar plates, the cooling flow field and gas flow field are independent. The design of the cooling flow field has a high degree of freedom but also increases complexity. Currently, in existing graphite bipolar plates, the cathode gas main, refrigerant main, and anode gas main are usually arranged sequentially on the short side of the graphite flow field plate, with the refrigerant main located in the middle and the inlet and outlet symmetrically distributed. The flow field design is limited by the width of the two sides.

[0005] Currently, there is considerable research and maturity in the cooling flow field arrangement of small-area square graphite bipolar plates. However, there are still significant shortcomings in the cooling flow field design for large-area rectangular commercial graphite bipolar plates, i.e., those with varying lengths and widths. Specifically, in order to improve compactness, the existing cooling flow field designs for commercial graphite bipolar plates place the inlet and outlet manifolds on the shorter sides of the plates. Furthermore, to reduce design complexity, regardless of whether the flow field is based on parallel or serpentine flow patterns, the flow channels are arranged gradually and uniformly from the inlet to the outlet, meaning that the coordinates of the flow channels along the length of the plates remain monotonically constant. This approach results in several drawbacks. Firstly, the flow channels have many bends and turns, and a small proportion of direct current channels, leading to large local losses and consequently, high pressure drop or pump power loss. Secondly, because the refrigerant absorbs heat along the flow direction, its temperature gradually increases, resulting in poor heat dissipation at the outlet. This leads to higher temperatures at the fuel cell outlet, deterioration of temperature distribution uniformity, and further degrades fuel cell performance or reduces its lifespan. Summary of the Invention

[0006] To address the technical problems existing in the prior art, this invention provides a graphite bipolar plate and a proton exchange membrane fuel cell, which solves the technical problems of large pressure drop or pump power loss in the cooling channels and poor uniformity of in-plane temperature distribution in existing commercial graphite bipolar plates, leading to a decline in fuel cell performance or a reduction in lifespan.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a graphite bipolar plate, comprising a plate body; a cathode inlet, a refrigerant inlet and an anode outlet are sequentially arranged from top to bottom on the first short side of the plate body; an anode inlet, a refrigerant outlet and a cathode outlet are sequentially arranged from top to bottom on the second short side of the plate body.

[0009] The surface of the electrode body is provided with cooling flow channels. The inlet of the cooling flow channel is connected to the refrigerant inlet, and the outlet of the cooling flow channel is connected to the refrigerant outlet. The cooling flow channel is divided into a first flow channel area, a second flow channel area, and a third flow channel area from top to bottom.

[0010] A first flow channel cluster arranged in a serpentine pattern is provided in the first flow channel region along the long side of the electrode body; a second flow channel cluster arranged in a serpentine pattern is provided in the second flow channel region along the long side of the electrode body; and a third flow channel cluster arranged in a serpentine pattern is provided in the third flow channel region along the long side of the electrode body.

[0011] Furthermore, the width l1 of the cathode inlet manifold at the cathode inlet is the same as the width of the cathode outlet manifold at the cathode outlet; the width l2 of the refrigerant inlet manifold at the refrigerant inlet is the same as the width of the refrigerant outlet manifold at the refrigerant outlet; and the width l3 of the anode inlet manifold at the anode inlet is the same as the width l3 of the anode outlet manifold at the anode outlet.

[0012] Furthermore, the width l1 of the cathode inlet manifold at the cathode inlet is greater than the width l3 of the anode outlet manifold at the anode outlet; the width of the cathode outlet manifold at the cathode outlet is greater than the width of the anode inlet manifold at the anode inlet.

[0013] Furthermore, the first flow channel cluster and the third flow channel cluster each fold back and forth three times along the long side of the electrode body; wherein, the first fold of the first flow channel cluster and the third flow channel cluster extends from the refrigerant inlet side along the long side of the electrode body to the refrigerant outlet side; wherein, the width of each fold of the first flow channel cluster and the third flow channel cluster is half the width l3 of the anode outlet main pipe.

[0014] Furthermore, the first flow channel cluster includes a plurality of first serpentine flow channels, which are arranged side by side along the long side of the electrode body; a first flow channel inlet bend section is provided between the inlet end of the first flow channel cluster and the refrigerant inlet manifold provided at the refrigerant inlet; wherein, the first flow channel inlet bend section is located in the inlet end region of the second flow channel area and is located close to the first flow channel area; one end of the first flow channel inlet bend section is connected to the refrigerant inlet manifold provided at the refrigerant inlet, and the other end of the first flow channel inlet bend section is matched and connected to the inlet end of the plurality of first serpentine flow channels;

[0015] When the width l2 of the refrigerant inlet manifold at the refrigerant inlet is greater than the width l3 of the anode outlet manifold at the anode outlet, the first flow channel inlet bend section includes several parallel first L-shaped bend flow channels, and the number of the first L-shaped bend flow channels is the same as the number of the first serpentine flow channels.

[0016] When the width l2 of the refrigerant inlet manifold at the refrigerant inlet is less than the width l3 of the anode outlet manifold at the anode outlet, the first flow channel inlet bend section includes several parallel one-to-many flow channels, and the total number of outlets of all the one-to-many flow channels is the same as the number of the first serpentine flow channels.

[0017] Furthermore, the second flow channel cluster includes a plurality of second serpentine flow channels, which are arranged side by side along the long side of the electrode body;

[0018] When the inlet width l4 of the second flow channel area is greater than one-third of the total width l5 of the second flow channel area, a second flow channel inlet bend section is provided between the inlet end of the second flow channel cluster and the refrigerant inlet manifold provided at the refrigerant inlet; wherein, one end of the second flow channel inlet bend section is connected to the inlet of the refrigerant manifold provided at the refrigerant inlet, and the other end of the second flow channel inlet bend section is matched and connected to the inlet ends of several second serpentine flow channels;

[0019] The second flow channel inlet bend section includes a plurality of second L-shaped bend flow channels. The number of second L-shaped bend flow channels is the same as the number of second serpentine flow channels, and the width of the bend portion of the second L-shaped bend flow channel along the short side direction of the electrode body is greater than the width of the second serpentine flow channel.

[0020] Furthermore, the second flow channel cluster includes a plurality of second serpentine flow channels, which are arranged side by side along the long side of the electrode body;

[0021] When the inlet width l4 of the second flow channel area is less than one-third of the total width l5 of the second flow channel area, a direct current channel connection section is provided between the inlet end of the second flow channel cluster and the refrigerant inlet manifold provided at the refrigerant inlet; wherein, one end of the direct current channel connection section is connected to the inlet of the refrigerant manifold provided at the refrigerant inlet, and the other end of the direct current channel connection section is matched and connected to the inlet ends of several second serpentine flow channels.

[0022] The DC channel connection section includes a number of straight channels, the number of which is the same as the number of the second serpentine channels, and the width of the straight channels is the same as the width of the second serpentine channels.

[0023] Furthermore, the second flow channel cluster folds back and forth three times along the long side of the electrode body; wherein, the first fold of the second flow channel cluster extends from the refrigerant inlet side along the long side of the electrode body to the refrigerant outlet side;

[0024] The width of the first fold of the second flow channel cluster and the width of the third fold of the second flow channel cluster are respectively adapted to the inlet width l4 of the second flow channel region; in the second fold of the second flow channel cluster, the width of the second serpentine flow channel is widened to fill the middle area of ​​the second flow channel region.

[0025] Furthermore, the third flow channel cluster includes several third serpentine flow channels, which are arranged side by side along the long side of the electrode body; a flow channel outlet bend section is provided between the outlet end of the third flow channel cluster and the refrigerant outlet manifold provided at the refrigerant outlet; wherein, the flow channel outlet bend section is located at the end region of the outlet end of the second flow channel area and is located close to the third flow channel area; the inlet end of the flow channel outlet bend section is matched and connected to the outlet end of several third serpentine flow channels, and the outlet end of the flow channel outlet bend section is connected to the refrigerant outlet manifold provided at the refrigerant outlet;

[0026] When the width of the refrigerant outlet manifold at the refrigerant outlet is greater than the width of the anode inlet manifold at the anode inlet, the flow channel outlet bend section includes several parallel third L-shaped bend flow channels, and the number of the third L-shaped bend flow channels is the same as the number of the third serpentine flow channels.

[0027] When the width of the refrigerant outlet manifold at the refrigerant outlet is less than the width of the anode inlet manifold at the anode inlet, the flow channel outlet bend section includes several multi-channels arranged in parallel, and the total number of inlets of all multi-channels is the same as the number of the third serpentine flow channels.

[0028] The present invention also provides a proton exchange membrane fuel cell, comprising the aforementioned graphite bipolar plate.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] This invention provides a graphite bipolar plate and proton exchange membrane fuel cell. The cathode inlet / outlet, refrigerant inlet / outlet, and anode inlet / outlet are located on the short side of the plate body. The cooling flow field is divided into three flow channel regions from top to bottom. Each flow channel region has a serpentine flow channel cluster arranged along the long side of the plate body. This significantly reduces the number of bends in the flow channel, increases the proportion of direct current channels, effectively reduces overall local pressure drop loss, and reduces the complexity of the flow channel structure. Furthermore, the serpentine arrangement of the flow channel cluster along the long side of the plate body ensures that the plate length coordinates along the long side no longer change monotonically, avoiding the monotonous increase in temperature from the refrigerant inlet to the refrigerant outlet. Under the same refrigerant flow rate, this effectively improves the uniformity of temperature distribution, thereby ensuring the fuel cell's performance and lifespan.

[0031] Further, the chamber sizes at the cathode inlet and outlet are set to be the same as the width of the cathode inlet and outlet header pipes, the chamber sizes at the anode inlet and outlet are set to be the same as the width of the anode inlet and outlet header pipes, and the chamber sizes at the refrigerant inlet and outlet are set to be the same as the width of the refrigerant inlet and outlet header pipes, so as to make the axial symmetry characteristics at the inlet and outlet positions. Combining the widths of different inlet and outlet header pipes, the corresponding flow channel sizes are designed, effectively improving the universality and expandability of the plate design.

[0032] Further, the first flow channel cluster, the second flow channel cluster and the third flow channel cluster are respectively folded back and forth three times along the long side direction of the plate body, and the first folds of the three flow channel clusters all extend from the refrigerant inlet to the refrigerant outlet side, enhancing the heat exchange capacity in the refrigerant outlet area, avoiding the generation of high temperature at the outlet position, and thus effectively improving the uniformity of the temperature distribution.

[0033] Further, according to the width dimension relationship of the inlet and outlet header pipes, the flow channel widths of the inlet section of the first flow channel cluster, the inlet and outlet sections of the second flow channel cluster and the outlet section of the third flow channel cluster are adjusted, so that the flow channels cover more heat exchange areas, and thus effectively reduce the inlet and outlet pressure drops. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the layout of the first flow channel area and the third flow channel area on the graphite bipolar plate described in the present invention;

[0035] Figure 2 When l2 > l3, Figure 1 Partial enlarged schematic diagram of point A in

[0036] Figure 3 When l2 < l3, Figure 1 Partial enlarged schematic diagram of point A in

[0037] Figure 4 Schematic diagram of the layout of the second flow channel area on the graphite bipolar plate described in the present invention; where l4 > l5 / 3;

[0038] Figure 5 For Figure 4 Partial enlarged schematic diagram of point B in

[0039] Figure 6 Schematic diagram of the layout of the second flow channel area on the graphite bipolar plate described in the present invention; where l4 < l5 / 3 <00所0092> Figure 7 For Figure 6 Partial enlarged schematic diagram of point C in

[0041] Figure 8 Front view of the graphite bipolar plate described in the embodiment;

[0042] Figure 9This is a three-dimensional structural diagram of the graphite bipolar plate described in the embodiment.

[0043] Among them, 1 is the cathode inlet, 2 is the refrigerant inlet, 3 is the anode outlet, 4 is the anode inlet, 5 is the refrigerant outlet, 6 is the cathode outlet, 7 is the first flow channel region, 8 is the second flow channel region, 9 is the third flow channel region, 10 is the first flow channel cluster, 11 is the second flow channel cluster, 12 is the third flow channel cluster; 13 is the first L-shaped bend flow channel, 14 is the one-to-many flow channel, 15 is the second L-shaped bend flow channel, 16 is the straight flow channel; 17 is the cooling flow field inlet, and 18 is the cooling flow field outlet. Detailed Implementation

[0044] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0045] As attached Figure 1-7 As shown, the present invention provides a graphite bipolar plate, including a plate body; the first short side of the plate body is provided with a cathode inlet 1, a refrigerant inlet 2 and an anode outlet 3 from top to bottom; a cathode inlet manifold is provided at the cathode inlet 1, a refrigerant inlet manifold is provided at the refrigerant inlet 2, and an anode outlet manifold is provided at the anode outlet 3; the second short side of the plate body is provided with an anode inlet 4, a refrigerant outlet 5 and a cathode outlet 6 from top to bottom; an anode inlet manifold is provided at the anode inlet 4, a refrigerant outlet manifold is provided at the refrigerant outlet 5, and a cathode outlet manifold is provided at the cathode outlet 6.

[0046] It should be noted that the inlet and outlet chambers of the anode gas, cathode gas, and refrigerant in the graphite bipolar plate correspond to each other. Specifically, the width l1 of the cathode inlet manifold is the same as the width of the cathode outlet manifold; the width l2 of the refrigerant inlet manifold is the same as the width of the refrigerant outlet manifold; the width of the anode inlet manifold is the same as the width l3 of the anode outlet manifold. Considering that when air is used as the cathode gas, since the oxygen volume ratio in the air is 21%, that is, the cathode air flow rate is greater than that on the anode side, the width l1 of the cathode inlet manifold is greater than the width l3 of the anode outlet manifold; and the width of the cathode outlet manifold is greater than the width of the anode inlet manifold.

[0047] The surface of the electrode body is provided with cooling flow channels, which are engraved on the surface of the electrode body. The cooling flow channels are located in the middle area of ​​the surface of the electrode body. The inlet of the cooling flow channels is connected to the refrigerant inlet 2, and the outlet of the cooling flow channels is connected to the refrigerant outlet 5. The cooling flow channels are divided into a first flow channel area 7, a second flow channel area 8, and a third flow channel area 9 from top to bottom. The first flow channel area 7 has a first flow channel cluster 10 arranged in a serpentine pattern along the long side of the electrode body. The second flow channel area 8 has a second flow channel cluster 11 arranged in a serpentine pattern along the long side of the electrode body. The third flow channel area 9 has a third flow channel cluster 12 arranged in a serpentine pattern along the long side of the electrode body.

[0048] The first flow channel cluster 10 folds back and forth three times along the long side of the electrode body. The inlet end of the first flow channel cluster 10 is connected to the refrigerant inlet manifold, and the outlet end of the first flow channel cluster 10 is connected to the refrigerant outlet manifold. The first fold of the first flow channel cluster 10 extends from the refrigerant inlet 2 side along the long side of the electrode body to the refrigerant outlet 5 side, and the width of each fold of the first flow channel cluster 10 is half the width l3 of the anode inlet manifold or anode outlet manifold.

[0049] The first flow channel cluster 10 includes a plurality of first serpentine flow channels, which are arranged side by side along the long side of the electrode body. The inlet end of all the first serpentine flow channels is connected to the refrigerant inlet manifold, and the outlet end of all the first serpentine flow channels is connected to the refrigerant outlet manifold. A first flow channel inlet bend section is provided between the inlet end of the first flow channel cluster 10 and the refrigerant inlet manifold. The first flow channel inlet bend section is located in the inlet end region of the second flow channel region 8 and is located close to the first flow channel region 7. One end of the first flow channel inlet bend section is connected to the refrigerant inlet manifold, and the other end of the first flow channel inlet bend section is matched and connected to the inlet section of the plurality of first serpentine flow channels.

[0050] The flow channel layout of the first flow channel inlet bend section is related to the width l2 of the refrigerant inlet main pipe and the width l3 of the anode outlet main pipe set at the anode outlet 3.

[0051] Specifically, when the width l2 of the refrigerant inlet manifold at the refrigerant inlet 2 is greater than the width l3 of the anode outlet manifold at the anode outlet 3, the first flow channel inlet bend section includes several parallel first L-shaped bend flow channels 13, the number of which is the same as the number of the first serpentine flow channels; wherein, the inlet end of the first L-shaped bend flow channel is connected to the refrigerant inlet manifold, and the outlet end of the first L-shaped bend flow channel is connected to the inlet end of the first serpentine flow channel in a one-to-one correspondence.

[0052] Specifically, when the width l2 of the refrigerant inlet manifold at the refrigerant inlet 2 is less than the width l3 of the anode outlet manifold at the anode outlet 3, the first flow channel inlet bend section includes a plurality of one-to-many flow channels 14 arranged in parallel. The total number of outlets of all the one-to-many flow channels 14 is the same as the number of the first serpentine flow channels. The total width of the inlet ends of all the one-to-many flow channels 14 is adapted to the width of the inlet end of the second flow channel area 8. The width of one outlet of each one-to-many flow channel is adapted to the width of a single first serpentine flow channel. The inlet end of each one-to-many flow channel 14 is connected to the refrigerant inlet manifold, and the outlet ends of all the one-to-many flow channels 14 are arranged one-to-one with the inlet ends of all the first serpentine flow channels. Preferably, the one-to-many flow channel 14 is a one-to-two flow channel or a one-to-three flow channel.

[0053] The second flow channel cluster 11 folds back and forth three times along the long side of the electrode body. The inlet end of the first flow channel cluster 11 is connected to the refrigerant inlet manifold, and the outlet end of the second flow channel cluster 11 is connected to the refrigerant outlet manifold. The first fold of the second flow channel cluster 11 extends from the refrigerant inlet 2 side along the long side of the electrode body to the refrigerant outlet 5 side.

[0054] The second flow channel cluster 11 includes a plurality of second serpentine flow channels, which are arranged side by side along the long side of the electrode body; the inlet end of all the second serpentine flow channels is connected to the refrigerant inlet manifold, and the outlet end of all the second serpentine flow channels is connected to the refrigerant outlet manifold; wherein, the width of the first fold and the width of the third fold of the second flow channel cluster 11 are respectively adapted to the inlet end width l4 of the second flow channel region 8; in the second fold of the second flow channel cluster 11, the width of the second serpentine flow channel is widened to fill the middle area of ​​the second flow channel region 8;

[0055] The flow channel layout at the inlet end of the second flow channel is related to the inlet width l4 of the second flow channel area 8 and the total width l5 of the second flow channel area 8.

[0056] Specifically, when the inlet width l4 of the second flow channel region 8 is greater than one-third of the total width l5 of the second flow channel region 8, a second flow channel inlet bend section is provided between the inlet end of the second flow channel cluster 11 and the refrigerant inlet manifold; wherein, one end of the second flow channel inlet bend section is connected to the refrigerant manifold inlet provided at the refrigerant inlet 2, and the other end of the second flow channel inlet bend section is matched and connected to the inlet ends of several second serpentine flow channels; the second flow channel inlet bend section includes several second L-shaped bend flow channels 15, the number of second L-shaped bend flow channels 15 is the same as the number of second serpentine flow channels and they are connected one by one, and the width of the turning part of the second L-shaped bend flow channel 15 along the short side direction of the electrode body is greater than the width of the second serpentine flow channel.

[0057] Specifically, when the inlet width l4 of the second flow channel region 8 is less than one-third of the total width l5 of the second flow channel region 8, a direct current channel connection section is provided between the inlet end of the second flow channel cluster 11 and the refrigerant inlet manifold; wherein, one end of the direct current channel connection section is connected to the refrigerant manifold inlet, and the other end of the direct current channel connection section is matched and connected to the inlet ends of several second serpentine flow channels; the direct current channel connection section includes several straight flow channels 16, the number of straight flow channels 16 is the same as the number of second serpentine flow channels and they are connected one-to-one, and the width of the straight flow channels 16 is the same as the width of the second serpentine flow channels.

[0058] Specifically, when the width of the outlet end of the second flow channel region 8 is greater than one-third of the total width l5 of the second flow channel region 8, an outlet bend section identical to the inlet bend section of the second flow channel is provided between the outlet end of the second flow channel cluster 11 and the refrigerant inlet outlet manifold. It should be noted that the inlet and outlet of the outlet bend section identical to the inlet bend section of the second flow channel are designed oppositely to the inlet and outlet of the inlet bend section of the second flow channel, and the other structural features are the same, which will not be described in detail here.

[0059] Specifically, when the width of the outlet end of the second flow channel region 8 is less than one-third of the total width l5 of the second flow channel region 8, an outlet connection section identical to the DC channel connection section is provided between the outlet end of the second flow channel cluster 11 and the refrigerant inlet / outlet manifold. It should be noted that the inlet and outlet of the outlet connection section identical to the DC channel connection section are designed oppositely to the inlet and outlet of the DC channel connection section, and the other structural features are the same, which will not be described in detail here.

[0060] The arrangement of the third flow channel cluster 12 is similar to that of the first flow channel 10, and is centrally symmetrical about the center of the electrode body. Specifically, the third flow channel cluster 12 folds back and forth three times along the long side of the electrode body. The inlet end of the third flow channel cluster 12 is connected to the refrigerant inlet manifold, and the outlet end of the third flow channel cluster 12 is connected to the refrigerant outlet manifold. The first fold of the third flow channel cluster 12 extends from the refrigerant inlet 2 side along the long side of the electrode body to the refrigerant outlet 5 side, and the width of each fold of the third flow channel cluster 12 is half the width l3 of the anode inlet manifold or anode outlet manifold.

[0061] The third flow channel cluster 10 includes several third serpentine flow channels arranged side by side along the long side of the electrode body; the inlet end of all the third serpentine flow channels is connected to the refrigerant inlet manifold, and the outlet end of all the third serpentine flow channels is connected to the refrigerant outlet manifold; wherein, a flow channel outlet bend section is provided between the outlet end of the third flow channel cluster 12 and the refrigerant outlet manifold, the flow channel outlet bend section is arranged in the outlet end region of the second flow channel region 8, and is arranged on the side close to the third flow channel region 9; the inlet end of the flow channel outlet bend section is matched and connected to the outlet end of several third serpentine flow channels, and the outlet end of the flow channel outlet bend section is connected to the refrigerant outlet manifold.

[0062] The flow channel layout of the bend section at the outlet is related to the width of the refrigerant outlet main pipe and the width of the anode inlet main pipe.

[0063] Specifically, when the width of the refrigerant outlet manifold is greater than the width of the anode inlet manifold, the flow channel outlet bend section includes several parallel third L-shaped bend flow channels, the number of which is the same as the number of third serpentine flow channels; wherein, the outlet end of the third L-shaped bend flow channel is connected to the refrigerant inlet manifold, and the inlet end of the third L-shaped bend flow channel is connected to the outlet end of the third serpentine flow channel in a one-to-one correspondence.

[0064] Specifically, when the width of the refrigerant outlet manifold is less than the width of the anode inlet manifold, the flow channel outlet bend section includes several multi-in-one flow channels, and the total number of inlets at all multi-in-one flow channels is the same as the number of third serpentine flow channels; the total width of the outlet ends of all multi-in-one flow channels is adapted to the width of the outlet end of the second flow channel area 8, and the width of one inlet of each multi-in-one flow channel is adapted to the width of a single third serpentine flow channel; wherein, the inlet ends of all multi-in-one flow channels are correspondingly set to the inlet ends of all third serpentine flow channels, and the outlet ends of all multi-in-one flow channels are connected to the refrigerant outlet manifold; preferably, the multi-in-one flow channel is a 2-in-1 flow channel or a 3-in-1 flow channel.

[0065] In this invention, the first flow channel cluster 10, the second flow channel cluster 11, and the third flow channel cluster 12 are all arranged in a serpentine pattern along the long side of the electrode body. The first bend of each flow channel cluster extends from the refrigerant inlet 2 along the long side of the electrode body to the refrigerant outlet 5 side, so that the refrigerant just entering the cooling flow field is first guided to the refrigerant outlet area, enhancing the heat exchange capacity of the refrigerant outlet area and avoiding high temperatures at the refrigerant outlet. Within each flow channel cluster, the flow channels are arranged in a serpentine pattern along the long side of the electrode body. Specifically, the first bend of the flow channel cluster is located at a coordinate... The coordinates of the second bend of the flow channel cluster in the long side direction of the electrode body decrease monotonically, while the coordinates of the third bend of the flow channel cluster in the long side direction of the electrode body increase monotonically, breaking the phenomenon of monotonically increasing temperature from refrigerant inlet to refrigerant outlet. Secondly, the serpentine flow channel cluster is arranged along the long side direction of the electrode body to reduce the number of bends in the serpentine flow channel cluster, increase the proportion of straight flow channels, and significantly reduce resistance loss. Using the design concept of cooling flow field channels given in this invention, the width of the serpentine flow channel can be flexibly adjusted to cover more heat exchange area, which is also conducive to further reducing pressure drop.

[0066] The present invention also provides a proton exchange membrane fuel cell, including the graphite bipolar plate described above. It should be noted that the structure of the proton exchange membrane fuel cell is similar to that of a conventional fuel cell, except that the electrode plate in the conventional fuel cell is replaced with the graphite bipolar plate described above. The specific structure will not be described in detail here.

[0067] Design principles:

[0068] The design objective of the graphite bipolar plate described in this invention is to improve the uniformity of temperature distribution and reduce the pressure drop on the graphite bipolar plate while ensuring heat exchange capacity. The design includes the following steps:

[0069] (1) Based on the design results of the proton exchange membrane fuel cell, customize the dimensions of the electrode body, the dimensions of the cooling flow field channel, the positions of cathode inlet 1, cathode refrigerant inlet 2, anode outlet 3, anode inlet 4, refrigerant outlet 5 and cathode outlet 6, and the width of the inlet and outlet manifold.

[0070] (2) Taking several parallel serpentine flow channels as a flow channel cluster, the orientation of a single flow channel cluster is arranged; wherein, the width of the single flow channel cluster is taken as half the width of the anode outlet manifold, and then the width and number of individual serpentine flow channels in the single flow channel cluster are determined; wherein, the orientation arrangement process of a single flow channel cluster is as follows:

[0071] (21) The orientation of the third flow channel cluster 12 within the third flow channel region 9;

[0072] Specifically, starting from the refrigerant inlet, the first bend of the third flow channel cluster 12 extends from one side of the refrigerant inlet 2 along the long side of the electrode body to the side of the refrigerant outlet 5. Then, it is arranged back and forth until the third flow channel cluster 12 bends back and forth three times along the long side of the electrode body and is connected to the refrigerant outlet manifold at the refrigerant outlet. Among them, after the refrigerant enters several third serpentine flow channels of the third flow channel cluster 12, it is guided to the refrigerant outlet area by the first bend of the third flow channel cluster 12, and then flows back and forth through the second and third bends of the second flow channel cluster 12 before flowing out. That is, the refrigerant flows out from the refrigerant outlet after being bend three times in the third serpentine flow channel of the third flow channel cluster.

[0073] Wherein, when the width of the refrigerant outlet manifold at the refrigerant outlet 5 is greater than the width of the anode inlet manifold at the anode inlet 4, the flow channel outlet bend section between the outlet end of the third flow channel cluster and the refrigerant outlet manifold adopts several parallel third L-shaped bend flow channels; when the width of the refrigerant outlet manifold at the refrigerant outlet 5 is less than the width of the anode inlet manifold at the anode inlet 4, the flow channel outlet bend section between the outlet end of the third flow channel cluster and the refrigerant outlet manifold adopts several parallel multi-in-one flow channels.

[0074] (22) The orientation of the first flow channel cluster 10 within the first flow channel region 7;

[0075] Specifically, starting from the refrigerant inlet, the first bend of the first flow channel cluster 10 extends from one side of the refrigerant inlet 2 along the long side of the electrode body to the side of the refrigerant outlet 5, and then is arranged back and forth until the first flow channel cluster 10 bends back and forth three times along the long side of the electrode body, and is then connected to the refrigerant outlet manifold at the refrigerant outlet; wherein, after the refrigerant enters several first serpentine flow channels of the first flow channel cluster 10, the refrigerant is guided by the first bend of the first flow channel cluster 10 to the refrigerant outlet area, and then flows back and forth through the second and third bends of the first flow channel cluster 10 to exit, that is, the refrigerant flows out from the refrigerant outlet after being folded back and forth three times in the first serpentine flow channel of the first flow channel cluster.

[0076] Specifically, when the width l2 of the refrigerant inlet manifold at refrigerant inlet 2 is greater than the width l3 of the anode outlet manifold at anode outlet 3, the first flow channel inlet bend section between the inlet end of the first flow channel cluster and the refrigerant outlet manifold adopts several parallel first L-shaped bend flow channels; when the width l2 of the refrigerant inlet manifold at refrigerant inlet 2 is less than the width l3 of the anode outlet manifold at anode outlet 3, the first flow channel inlet bend section between the inlet end of the first flow channel cluster and the refrigerant outlet manifold adopts several parallel one-to-many flow channels.

[0077] (23) The orientation of the first flow channel cluster 11 within the second flow channel region 8;

[0078] Specifically, starting from the refrigerant inlet, the first bend of the second flow channel cluster 11 extends from one side of the refrigerant inlet 2 along the long side of the electrode body to the side of the refrigerant outlet 5, and then is arranged back and forth until the second flow channel cluster 11 bends back and forth three times along the long side of the electrode body, and is then connected to the refrigerant outlet manifold at the refrigerant outlet; wherein, after the refrigerant enters several first serpentine flow channels of the second flow channel cluster 11, the refrigerant is guided by the first bend of the second flow channel cluster 11 to the refrigerant outlet area, and then flows back and forth through the second bend and the third bend of the second flow channel cluster 11 to exit, that is, the refrigerant flows out from the refrigerant outlet after being turned back three times in the second serpentine flow channel of the second flow channel cluster.

[0079] Specifically, when the inlet width l4 of the second flow channel region 8 is greater than one-third of the total width l5 of the second flow channel region 8, the inlet end of the second flow channel cluster 11 is connected to the refrigerant inlet manifold using a second flow channel inlet bend section; when the outlet width of the second flow channel region 8 is greater than one-third of the total width l5 of the second flow channel region 8, the outlet end of the second flow channel cluster 11 is connected to the refrigerant inlet outlet manifold using an outlet bend section identical to the second flow channel inlet bend section; when the inlet width l4 of the second flow channel region 8 is less than one-third of the total width l5 of the second flow channel region 8, the inlet end of the second flow channel cluster 11 is connected to the refrigerant inlet manifold using a direct flow channel connection section; when the outlet width of the second flow channel region 8 is less than one-third of the total width l5 of the second flow channel region 8, the outlet end of the second flow channel cluster 11 is connected to the refrigerant inlet outlet manifold using an outlet connection section identical to the direct flow channel connection section.

[0080] It should be noted that the second flow channel region 8 has axisymmetric features, and the second flow channel cluster adopts a serpentine flow channel structure with three folds. In the second fold of the second flow channel cluster, the width of the second serpentine flow channel is increased to fill the entire middle area of ​​the second flow channel region 8. When the width of the inlet section or the width of the outlet section of the second flow channel cluster is greater than the width of a single second flow channel cluster, a turn can be introduced and the flow channel widened to cover more heat exchange area.

[0081] The following is a detailed explanation of the flow channel arrangement process of the first flow channel region 7 and the second flow channel region 8: The long side direction of the electrode body is defined as the X-axis direction, and the coordinate of the long side direction of the electrode body is set to x∈(0,a). The short side direction of the electrode body is defined as the Y-axis direction, and the coordinate of the short side direction of the electrode body is set to y∈(0,b).

[0082] Within the first flow channel region 7, the first flow channel cluster 10 is arranged in the form of a number of serpentine flow channels arranged in parallel; generally speaking, the first flow channel cluster 10 folds back and forth three times along the long side direction of the plate body, i.e., the X-axis direction; after the refrigerant enters, it is guided into the first fold of the first flow channel cluster 10 towards the refrigerant outlet side, and after passing through the second and third folds of the first flow channel cluster 10, it flows out from the refrigerant outlet; as shown in the appendix Figure 1 shown, the appendix Figure 1 The arrows in the first flow channel region in the figure represent the first flow channel cluster 10 composed of a number of first serpentine flow channels; among them, the width of the first flow channel cluster 10 is half of the width l3 of the anode outlet main pipe, and the width of the first flow channel cluster 10 includes the ridge width.

[0083] According to the relative sizes of the widths of the refrigerant inlet and outlet main pipes and the anode inlet and outlet main pipes, the structure of the first flow channel inlet corner section at the inlet of the first flow channel cluster 10 is different; when l2 > l3, the first flow channel inlet corner section adopts the structural form of a number of first L-shaped corner flow channels 13 arranged in parallel, as shown in the appendix Figure 2 shown; when l2 < l3, the first flow channel inlet corner section adopts the structural form of a number of one-to-multiple flow channels 14 arranged in parallel, as shown in the appendix Figure 3 shown; compared with Figure 2 and Figure 3 the structure of the first flow channel inlet corner section in the figure, when the width of the refrigerant inlet main pipe is not sufficient to accommodate two clusters of first flow channel clusters, a 1-to-2 flow channel or 1-to-3 flow channel or a combination of both is adopted to reduce the width of the first flow channel cluster at the inlet.

[0084] Within the second flow channel region, the second flow channel cluster 11 is arranged in the form of a number of serpentine flow channels arranged in parallel; generally speaking, the second flow channel cluster 11 folds back and forth three times along the long side direction of the plate body, i.e., the X-axis direction; after the refrigerant enters, it is guided into the first fold of the second flow channel cluster 11 towards the refrigerant outlet side, and after passing through the second and third folds of the second flow channel cluster 11, it flows out from the refrigerant outlet, as shown in the appendix Figure 4 shown.

[0085] According to the relative sizes of the width l4 of the corresponding inlet section of the second flow channel region 8 and the total width l5 of the second flow channel region 8, the arrangement types at the inlet and outlet of the second flow channel cluster 11 are slightly different; specifically, when l4 > l5 / 3, second flow channel inlet corner sections are adopted both between the inlet end of the second flow channel cluster 11 and the refrigerant inlet main pipe and between the outlet end of the second flow channel cluster 11 and the refrigerant outlet main pipe, as shown in the appendix Figure 4-5 ; when l4 < l5 / 3, straight flow channel connection sections are adopted both between the inlet end of the second flow channel cluster 11 and the refrigerant inlet main pipe and between the outlet end of the second flow channel cluster 11 and the refrigerant outlet main pipe, as shown in the appendix Figure 6-7 shown.

[0086] In the inlet corner section of the second flow channel, since the inlet width is greater than the width of the second flow channel cluster, in order to maximize the coverage area of the cooling flow field as much as possible, a turn is taken in the inlet corner section of the second flow channel and the width of the flow channel in the intermediate transition section is increased; in the straight flow channel connection section, the total width of several straight flow channels is equal to the inlet width and is arranged in one-to-one correspondence with the second serpentine flow channel; in the second fold of the second flow channel cluster, by changing the width of the second serpentine flow channel, the area between the first fold and the third fold of the second flow channel section is filled.

[0087] Embodiment

[0088] In this embodiment, taking a commercial PEMFC graphite bipolar plate with a length of 225 mm and a width of 130 mm as an example, the graphite bipolar plate is designed according to the layout form of the cooling flow field channels described in the present invention; as shown in the appendix Figure 8 As shown, the cooling flow field inlet 17 is arranged in the middle of the first short side of the graphite bipolar plate, and the cooling flow field outlet 18 is arranged on the second short side of the graphite bipolar plate.

[0089] In this embodiment, l2 > l3 and l4 < l5 / 3. Therefore, according to the design form of the graphite bipolar plate described in the present invention, in the first flow channel area 7, several one-to-many flow channels arranged in parallel are used to connect the inlet end of the first flow channel cluster and the refrigerant inlet main pipe; in the second flow channel area 8, a straight flow channel connection section is used to connect the inlet end of the second flow channel cluster and the refrigerant inlet main pipe, and a straight flow channel connection section is used to connect the outlet end of the second flow channel cluster and the refrigerant outlet main pipe; in the third flow channel 9, several multi-to-one flow channels arranged in parallel are used to connect the outlet end of the third flow channel cluster and the refrigerant outlet main pipe.

[0090] As shown in the appendix Figure 9 As shown, the appendix Figure 9 shows a three-dimensional structure schematic diagram of the graphite bipolar plate; wherein, the upper surface of the graphite bipolar plate is provided with cooling flow field channels, and the cooling flow field channels are formed by engraving on the upper surface of the graphite bipolar plate.

[0091] In this embodiment, in the first flow channel area 7, the first flow channel cluster includes 7 first serpentine flow channels; among them, the width of the first serpentine flow channel is 1.2 mm and the ridge width is 0.8 mm; in the second flow channel area 8, the second flow channel cluster includes 4 second serpentine flow channels; among them, the width of the second serpentine flow channel is 1.2 mm or 4 mm and the ridge width is 0.8 mm; in the third flow channel area 7, the third flow channel cluster includes 7 third serpentine flow channels; among them, the width of the third serpentine flow channel is 1.2 mm and the ridge width is 0.8 mm.

[0092] The graphite bipolar plate described in this embodiment eliminates the high-temperature region at the outlet, improves the uniformity of temperature distribution, reduces the complexity of the flow channel layout, and decreases the inlet and outlet pressure drop.

[0093] In this invention, the inlet and outlet manifolds for the gas and refrigerant are arranged on the short side of the electrode plate body to improve the compactness of the stack. The inlets and outlets of the three chambers for anode gas, cathode gas, and refrigerant correspond to each other, i.e., the inlet and outlet manifolds have the same dimensions. The design process of the graphite bipolar plate is both versatile and flexible, applicable to large-area commercial bipolar plates of any size combination. It considers the axisymmetric characteristics of the inlet and outlet positions and provides specific design methods under different inlet and outlet manifold widths. The cooling flow field of the graphite bipolar plate can efficiently remove the heat generated by the battery while significantly improving the uniformity of temperature distribution in the battery plane, and reducing the pump power consumed to maintain the flow of the cooling circuit.

[0094] The graphite bipolar plate of this invention retains the original design of arranging the inlet and outlet on the short side of the plate. The design process of the cooling flow channel has high versatility and scalability. Unlike the traditional flow field where there are many turns along the channel, in this invention, the serpentine channel is spread along the long side of the plate, which significantly reduces the number of turns, increases the proportion of the direct current channel, effectively reduces the overall local pressure drop loss, and reduces the complexity of the flow channel structure.

[0095] In this invention, based on a multi-serpentine flow channel arrangement, only the total width of a single flow channel cluster is fixed. The width of a single serpentine flow channel has a certain degree of flexibility. In some areas, the width of a single flow channel can be increased or the ridge width can be decreased to cover more heat exchange area and more fluid domain space, which can further reduce the pressure drop at the inlet and outlet. Secondly, each flow channel cluster is arranged serpentinely along the long side of the electrode plate so that after the refrigerant flows into the flow field, it will be guided to the outlet position first, and then make three turns along the long side. Under the condition of constant heat flux density, the lower the temperature of the refrigerant, the stronger its heat exchange capacity, effectively reducing the local high temperature at the outlet and breaking the monotonically increasing temperature distribution pattern from the inlet to the outlet in the traditional design. It can effectively improve the uniformity of temperature distribution under the same refrigerant flow rate.

[0096] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A graphite bipolar plate, characterized in that, It includes an electrode plate body; the first short side of the electrode plate body is provided with a cathode inlet (1), a refrigerant inlet (2) and an anode outlet (3) from top to bottom; the second short side of the electrode plate body is provided with an anode inlet (4), a refrigerant outlet (5) and a cathode outlet (6) from top to bottom. The surface of the electrode body is provided with cooling flow channels. The inlet of the cooling flow channel is connected to the refrigerant inlet (2), and the outlet of the cooling flow channel is connected to the refrigerant outlet (5). The cooling flow channel is divided into a first flow channel area (7), a second flow channel area (8), and a third flow channel area (9) from top to bottom. The first flow channel region (7) is provided with a first flow channel cluster (10) arranged in a serpentine pattern along the long side of the electrode body, the second flow channel region (8) is provided with a second flow channel cluster (11) arranged in a serpentine pattern along the long side of the electrode body, and the third flow channel region (9) is provided with a third flow channel cluster (12) arranged in a serpentine pattern along the long side of the electrode body.

2. A graphite bipolar plate according to claim 1, characterized in that, The width l1 of the cathode inlet manifold provided at the cathode inlet (1) is the same as the width of the cathode outlet manifold provided at the cathode outlet (6); the width l2 of the refrigerant inlet manifold provided at the refrigerant inlet (2) is the same as the width of the refrigerant outlet manifold provided at the refrigerant outlet (5); the width of the anode inlet manifold provided at the anode inlet (4) is the same as the width l3 of the anode outlet manifold provided at the anode outlet (3).

3. A graphite bipolar plate according to claim 1, characterized in that, The width l1 of the cathode inlet manifold provided at the cathode inlet (1) is greater than the width l3 of the anode outlet manifold provided at the anode outlet (3); the width of the cathode outlet manifold provided at the cathode outlet (6) is greater than the width of the anode inlet manifold provided at the anode inlet (4).

4. A graphite bipolar plate according to claim 1, characterized in that, The first flow channel cluster (10) and the third flow channel cluster (12) fold back and forth three times along the long side of the electrode body; wherein, the first fold of the first flow channel cluster (10) and the third flow channel cluster (12) extends from the side of the refrigerant inlet (2) along the long side of the electrode body to the side of the refrigerant outlet (5); wherein, the width of each fold of the first flow channel cluster (10) and the third flow channel cluster (12) is half the width l3 of the anode outlet main pipe.

5. A graphite bipolar plate according to claim 1, characterized in that, The first flow channel cluster (10) includes several first serpentine flow channels, which are arranged side by side along the long side of the electrode body; a first flow channel inlet bend section is provided between the inlet end of the first flow channel cluster (10) and the refrigerant inlet manifold provided at the refrigerant inlet (2); wherein, the first flow channel inlet bend section is arranged in the inlet end region of the second flow channel area (8) and is arranged close to the side of the first flow channel area (7); one end of the first flow channel inlet bend section is connected to the refrigerant inlet manifold provided at the refrigerant inlet (2), and the other end of the first flow channel inlet bend section is matched and connected to the inlet end of several first serpentine flow channels; When the width l2 of the refrigerant inlet manifold provided at the refrigerant inlet (2) is greater than the width l3 of the anode outlet manifold provided at the anode outlet (3), the first flow channel inlet bend section includes several parallel first L-shaped bend flow channels (13), and the number of the first L-shaped bend flow channels (13) is the same as the number of the first serpentine flow channels. When the width l2 of the refrigerant inlet manifold provided at the refrigerant inlet (2) is less than the width l3 of the anode outlet manifold provided at the anode outlet (3), the first flow channel inlet bend section includes several parallel one-to-many flow channels (14), and the total number of outlets of all the one-to-many flow channels (14) is the same as the number of the first serpentine flow channels.

6. A graphite bipolar plate according to claim 1, characterized in that, The second flow channel cluster (11) includes a plurality of second serpentine flow channels, which are arranged side by side along the long side of the electrode body; When the inlet width l4 of the second flow channel area (8) is greater than one-third of the total width l5 of the second flow channel area (8), a second flow channel inlet bend section is provided between the inlet end of the second flow channel cluster (11) and the refrigerant inlet manifold provided at the refrigerant inlet (2); wherein, one end of the second flow channel inlet bend section is connected to the inlet of the refrigerant manifold provided at the refrigerant inlet (2), and the other end of the second flow channel inlet bend section is matched and connected to the inlet ends of several second serpentine flow channels; The second flow channel inlet bend section includes a plurality of second L-shaped bend flow channels (15), the number of the second L-shaped bend flow channels (15) is the same as the number of the second serpentine flow channels, and the width of the bend portion of the second L-shaped bend flow channel (15) along the short side direction of the electrode body is greater than the width of the second serpentine flow channel.

7. A graphite bipolar plate according to claim 1, characterized in that, The second flow channel cluster (11) includes a plurality of second serpentine flow channels, which are arranged side by side along the long side of the electrode body; When the inlet width l4 of the second flow channel area (8) is less than one-third of the total width l5 of the second flow channel area (8), a direct current channel connection section is provided between the inlet end of the second flow channel cluster (11) and the refrigerant inlet main pipe provided at the refrigerant inlet (2); wherein, one end of the direct current channel connection section is connected to the refrigerant main pipe inlet provided at the refrigerant inlet (2), and the other end of the direct current channel connection section is matched and connected to the inlet ends of several second serpentine flow channels; The DC channel connection section includes a number of straight channels (16), the number of which is the same as the number of the second serpentine channels, and the width of the straight channels (16) is the same as the width of the second serpentine channels.

8. A graphite bipolar plate according to claim 6 or 7, wherein the second flow channel cluster (11) folds back and forth three times along the long side of the plate body; wherein, The first bend of the second flow channel cluster (11) extends from the refrigerant inlet (2) side along the long side of the electrode body to the refrigerant outlet (5) side; The width of the first fold of the second flow channel cluster (11) and the width of the third fold of the second flow channel cluster (11) are respectively adapted to the inlet width l4 of the second flow channel region (8); in the second fold of the second flow channel cluster (11), the width of the second serpentine flow channel is widened to fill the middle area of ​​the second flow channel region (8).

9. A graphite bipolar plate according to claim 1, characterized in that, The third flow channel cluster (12) includes several third serpentine flow channels, which are arranged side by side along the long side of the electrode body; a flow channel outlet bend section is provided between the outlet end of the third flow channel cluster and the refrigerant outlet main pipe provided at the refrigerant outlet (5); wherein, the flow channel outlet bend section is arranged in the outlet end region of the second flow channel area (8) and is located close to the third flow channel area (9); the inlet end of the flow channel outlet bend section is matched and connected to the outlet end of several third serpentine flow channels, and the outlet end of the flow channel outlet bend section is connected to the refrigerant outlet main pipe provided at the refrigerant outlet (5); When the width of the refrigerant outlet main pipe provided at the refrigerant outlet (5) is greater than the width of the anode inlet main pipe provided at the anode inlet (4), the flow channel outlet bend section includes several parallel third L-shaped bend flow channels, and the number of the third L-shaped bend flow channels is the same as the number of the third serpentine flow channels. When the width of the refrigerant outlet manifold provided at the refrigerant outlet (5) is less than the width of the anode inlet manifold provided at the anode inlet (4), the flow channel outlet bend section includes several multi-in-one flow channels arranged in parallel, and the total number of inlets of all the multi-in-one flow channels is the same as the number of the third serpentine flow channels.

10. A proton exchange membrane fuel cell, characterized in that, Including a graphite bipolar plate as described in any one of claims 1-9.

Images