Bipolar plate structure for realizing flow field distribution area and PEM fuel cell

Abstract

The invention discloses a bipolar plate structure for realizing a flow field distribution area and a PEM fuel cell. The provided polar plate comprises a hydrogen flow field, an air flow field and a cooling water flow field, flow field distribution areas are arranged in inlet and outlet areas of the flow fields, and a flow path of fluid under structural intervention of the flow field distribution areas is formed. A bipolar plate flow field air inlet distribution area is divided into three parts, namely an air inlet area, a transition area and a distribution area. The air inlet area flow channel is perpendicular to the edge of the large channel, the length of the flow channel is gradually increased, and the transition area flow channel is parallel to the adjacent sealing groove inner groove. A one-to-multiple flow channel is arranged in the distribution area, and the ridge of the one-to-multiple flow channel is regularly arranged. And the ridge width in the hydrogen / air electrochemical active region is designed to be greater than the width of the flow channel. The bipolar plate distribution area design provided by the invention can solve the problem of local hot spots caused by non-uniform gas distribution, realizes maximization of the area utilization rate of the polar plate, prevents the plate from being damaged due to long-term stress concentration, and prolongs the service life of the fuel cell.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, in particular to a bipolar plate structure for realizing a flow field distribution zone and a PEM fuel cell. Background Art

[0002] Fuel cells are energy conversion devices that can directly and efficiently convert the chemical energy of reactants into electrical energy. Fuel cells do not generate noise during operation. When a fuel cell uses hydrogen as fuel, the only reaction product is water, which can achieve the goal of zero pollution emissions. Proton exchange membrane (PEM) fuel cells have the advantages of high energy density and low starting temperature, and are widely used in various fields including transportation, backup power and mobile equipment. The bipolar plate flow field structure is a key link in fuel cells. If the design of the inlet / exhaust distribution area of ​​the flow field is unreasonable, it is easy to have problems with uneven internal mass transfer. At the same time, it is easy to cause stress concentration on the bipolar plate after pressing, thereby accelerating the reduction of the battery life. For the cooling water flow field, the design of the inlet / exhaust distribution area will also affect the bonding ability between the air-water plate and the hydrogen plate, thereby affecting the sealing of the battery. Summary of the invention

[0003] The present invention provides a bipolar plate structure and a PEM fuel cell for realizing a flow field distribution area. When the reaction gas and cooling water enter the flow field, the uniformity of the distribution of the fluid in each branch flow channel is ensured, and at the same time, the surface conductivity of the bipolar plate is improved and the problem of uneven distribution stress of the press-fitting distribution is dispersed, thereby improving the performance and service life of the fuel cell.

[0004] In the first aspect, a bipolar plate structure for realizing a flow field distribution area is provided, comprising an air-water plate and a hydrogen plate, which are bonded to form a set of bipolar plate structures; the hydrogen plate forms a hydrogen flow field of a PEM fuel cell, and the front and back sides of the air-water plate are respectively an air flow field and a cooling water flow field of the PEM fuel cell; the cooling water flow field is located between the hydrogen flow field and the air flow field;

[0005] A large hydrogen inlet channel, a large air inlet channel, and a large cooling water inlet channel are provided on the first side of the bipolar plate structure, and the large cooling water inlet channel is located between the large hydrogen inlet channel and the large air inlet channel;

[0006] The second side of the bipolar plate structure is provided with a hydrogen exhaust channel, an air exhaust channel, and a cooling water drainage channel, wherein the cooling water drainage channel is located between the hydrogen exhaust channel and the air exhaust channel; the hydrogen intake channel and the hydrogen exhaust channel are centrally symmetrical; the air intake channel and the air exhaust channel are centrally symmetrical; the cooling water intake channel and the cooling water drainage channel are centrally symmetrical; the bipolar plate structure satisfies at least one of the following:

[0007] The hydrogen flow field includes a hydrogen inlet distribution area, a hydrogen electrochemical reaction active area and a hydrogen exhaust distribution area; the hydrogen inlet distribution area of ​​the hydrogen flow field includes a hydrogen inlet area, a hydrogen transition area and a hydrogen distribution area; the flow channel of the hydrogen inlet area is perpendicular to the edge of the hydrogen inlet large channel, and all the flow channels in the hydrogen transition area are parallel to the edge of the closest sealing groove; the hydrogen distribution area adopts a one-to-four flow channel structure, and the arrangement of the three ridges in each one-to-four channel in the hydrogen distribution area is gradient distributed; each ridge of the hydrogen flow field is in contact with the anode diffusion layer; the hydrogen exhaust distribution area of ​​the hydrogen flow field is symmetrical with the center of the hydrogen inlet distribution area; the hydrogen electrochemical reaction active area is provided with a flow field structure of a straight channel;

[0008] The air flow field includes an air intake distribution area, an air electrochemical reaction active area and an air exhaust distribution area; the air intake distribution area of ​​the air flow field includes an air intake area, an air transition area and an air distribution area; the flow channel of the air intake area is perpendicular to the edge of the large air intake channel, and all the flow channels in the air transition area are parallel to the edge of the closest sealing groove; the air distribution area adopts a one-to-four flow channel structure, and the arrangement of the three ridges in each one-to-four channel in the air distribution area is gradient distributed; each ridge on the air flow field side is covered with a cathode diffusion layer; the air exhaust distribution area of ​​the air flow field is symmetrical with the center of the air intake distribution area; the air electrochemical reaction active area is provided with a flow field structure of a straight flow channel;

[0009] The cooling water flow field includes a water inlet distribution area, an electrochemical reaction heat exchange area and a drainage distribution area; the water inlet distribution area is divided into a cooling water inlet area and a cooling water distribution area; the angle formed by the flow channel of the cooling water inlet area and the upper edge of the cooling water inlet channel ranges from 0° to 19°; the cooling water distribution area adopts a one-to-four flow channel structure, and the arrangement of the ridges in each one-to-four channel in the cooling water distribution area is gradiently distributed, and the drainage distribution area is symmetrical with the center of the water inlet distribution area; the electrochemical reaction heat exchange area is provided with a straight flow channel flow field structure.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the flow channel length of the hydrogen inlet zone close to the cooling water inlet channel is smaller than the flow channel length of the hydrogen inlet zone away from the cooling water inlet channel; the flow channel length of the hydrogen inlet zone gradually increases in the direction approaching the hydrogen distribution zone.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the first portion of the flow channel in the hydrogen transition zone is arranged relatively close to the hydrogen gas inlet channel, the first portion of the flow channel in the hydrogen transition zone is arranged opposite to the cooling water inlet channel, and the sealing groove between the first portion of the flow channel in the hydrogen transition zone and the cooling water inlet channel is parallel to the first portion of the flow channel in the hydrogen transition zone; the angle between the first portion of the flow channel in the hydrogen transition zone and the hydrogen distribution zone is 90°;

[0012] The second portion of the flow channel in the hydrogen transition zone extends relatively away from the hydrogen inlet channel; the proximal end of the second portion of the flow channel in the hydrogen transition zone is arranged opposite to the cooling water inlet channel, and the sealing groove between the proximal end of the second portion of the flow channel in the hydrogen transition zone and the cooling water inlet channel remains parallel to the proximal end of the second portion of the flow channel in the hydrogen transition zone; the proximal end of the second portion of the flow channel in the hydrogen transition zone is at an angle of 90° to the hydrogen distribution zone; the distal end of the second portion of the flow channel in the hydrogen transition zone is arranged opposite to the air inlet channel, and the sealing groove between the distal end of the second portion of the flow channel in the hydrogen transition zone and the air inlet channel remains parallel to the distal end of the second portion of the flow channel in the hydrogen transition zone; the distal end of the second portion of the flow channel in the hydrogen transition zone is at an angle of 110° to the hydrogen distribution zone.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the absolute value of the angle formed by the line connecting the centers of the ridge edge circles and the central vertical line in the four flow channels in the hydrogen distribution area ranges from 7° to 29°; the angle formed by the line connecting the centers of the ridge edge circles and the central vertical line first increases and then decreases from bottom to top.

[0014] In conjunction with the first aspect, in certain implementations of the first aspect, the hydrogen flow field satisfies at least one of the following:

[0015] The flow channel of the hydrogen inlet area forms an angle of 90° with the edge of the large hydrogen inlet channel;

[0016] The angle between the hydrogen inlet area and the hydrogen distribution area is 143°;

[0017] The ridge width between two adjacent flow channels in the hydrogen transition zone is 1.32 mm, and the flow channel width is 0.52 mm;

[0018] The ridge width between two adjacent flow channels in the hydrogen inlet area is 1.32 mm, and the flow channel width is 0.52 mm;

[0019] The ridge width in the one-to-four flow channels in the hydrogen distribution area is 0.4 mm;

[0020] The width of the flow channel between two adjacent ridges in the one-to-four flow channel in the hydrogen distribution area is 0.58 mm;

[0021] The ridge width between two adjacent one-to-four flow channels in the hydrogen distribution area is 4.32 mm;

[0022] In the hydrogen distribution area, in the 1st to 4th four-way flow channels from bottom to top, the absolute value of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line is 7°; in the 5th to 8th four-way flow channels from bottom to top, the absolute value of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line is 27°; in the 9th to 10th four-way flow channels from bottom to top, the absolute values ​​of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line are 21° and 29° respectively; the angle between the line connecting the centers of the ridge edges of the 4th four-way flow channel and the line connecting the centers of the ridge edges of the 5th four-way flow channel is 146°.

[0023] In combination with the first aspect, in certain implementations of the first aspect, the flow length of the air intake zone close to the cooling water inlet channel is smaller than the flow length of the air intake zone away from the cooling water inlet channel; the flow length of the air intake zone gradually increases in the direction approaching the air distribution zone.

[0024] In combination with the first aspect, in some implementations of the first aspect, the first partial flow channel of the air transition zone is arranged relatively close to the large air intake channel, the first partial flow channel of the air transition zone is arranged opposite to the large cooling water intake channel, and the sealing groove between the first partial flow channel of the air transition zone and the large cooling water intake channel is parallel to the first partial flow channel of the air transition zone; the first partial flow channel of the air transition zone is at an angle of 90° relative to the air distribution zone;

[0025] The second part of the flow channel in the air transition zone extends relatively far away from the large air intake channel; the proximal end of the second part of the flow channel in the air transition zone is arranged opposite to the large cooling water intake channel, and the sealing groove between the proximal end of the second part of the flow channel in the air transition zone and the large cooling water intake channel remains parallel to the proximal end of the second part of the flow channel in the air transition zone; the proximal end of the second part of the flow channel in the air transition zone is at an angle of 90° to the air distribution zone; the distal end of the second part of the flow channel in the air transition zone is arranged opposite to the large hydrogen intake channel, and the sealing groove between the distal end of the second part of the flow channel in the air transition zone and the large hydrogen intake channel remains parallel to the distal end of the second part of the flow channel in the air transition zone; the distal end of the second part of the flow channel in the air transition zone is at an angle of 127° to the air distribution zone.

[0026] In conjunction with the first aspect, in some implementations of the first aspect, the air flow field satisfies at least one of the following:

[0027] The angle between the flow channel of the air intake area and the edge of the large air intake channel is 90 degrees;

[0028] The angle between the air intake area and the air distribution area is 160°;

[0029] The ridge width between two adjacent flow channels in the air transition zone is 1.84 mm, and the flow channel width is 1.04 mm;

[0030] The ridge width between two adjacent flow channels in the air intake area is 1.32 mm, and the flow channel width is 0.52 mm;

[0031] The ridge width in the one-to-four flow channels in the air distribution area is 0.4 mm;

[0032] The flow channel width between two adjacent ridges in the one-to-four flow channels in the air distribution area is 0.58 mm;

[0033] The ridge width between two adjacent one-to-four flow channels in the air distribution area is 4.32 mm;

[0034] In the air distribution area, the angle between the center line of the inner ridge edge of the 1st to 2nd four-channel flow channel from bottom to top and the central vertical line is 33°~39°; the angle between the center line of the inner ridge edge of the 3rd to 10th four-channel flow channel from bottom to top and the central vertical line is 12°; the angle between the center line of the inner ridge edge of the 11th four-channel flow channel from bottom to top and the central vertical line is 15°.

[0035] In combination with the first aspect, in certain implementations of the first aspect, an intermediate extension ridge is provided in the 11th to 13th one-divided-in-four channels from the top to the bottom; the intermediate extension ridge extends from the edge of the ridge toward the cooling water inlet area in the flow channel; the extension angle of the intermediate extension ridge is half of the sum of the inclination angles of the edges on both sides of the one-divided-in-four channels where the intermediate extension ridge is located.

[0036] In combination with the first aspect, in certain implementations of the first aspect, in the cooling water distribution area, except for the 11th to 13th one-in-four channels from top to bottom, the angle formed by the line connecting the centers of the spine edges and the central vertical line of the remaining one-in-four channels ranges from 23° to 53°, and the angle between the line connecting the centers of the spine edges and the central vertical line from both sides to the middle first decreases and then increases; in terms of the angle between the line connecting the centers of the spine edges and the central vertical line, the 1st to 10th one-in-four channels from bottom to top are symmetrical with the 1st to 10th one-in-four channels from top to bottom, respectively.

[0037] In conjunction with the first aspect, in certain implementations of the first aspect, the cooling water flow field satisfies at least one of the following:

[0038] There are 19 cooling water inlet area flow channels, and the angles formed with the upper edge of the cooling water inlet channel are 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, and 19° from top to bottom;

[0039] From top to bottom, the angles between the line connecting the center of the dorsal edge and the vertical line of the center are 31°, 32°, 33°, 32°, 31°, 30°, 29°, 28°, 49°, and 53° for the 1st to 10th four-channel respectively;

[0040] From top to bottom, the angles of the middle extended ridges in the 11th to 13th one-fourth channel relative to the central vertical line are 63°, 52°, and 48° respectively;

[0041] In the 11th to 13th one-to-four channels from top to bottom, each one-to-four flow channel has extended sharp corner structures on both sides of the middle extended ridge; the arc radius of the upper extended sharp corner structure is 2.42mm, and the arc radius of the lower extended sharp corner structure is 4.08mm.

[0042] In the second aspect, a hydrogen electrode plate is provided to form a hydrogen flow field of a PEM fuel cell; the hydrogen flow field includes a hydrogen inlet distribution area, a hydrogen electrochemical reaction active area and a hydrogen exhaust distribution area; the hydrogen inlet distribution area of ​​the hydrogen flow field includes a hydrogen inlet area, a hydrogen transition area and a hydrogen distribution area; the flow channel of the hydrogen inlet area is perpendicular to the edge of the hydrogen inlet large channel, and all the flow channels in the hydrogen transition area are parallel to the edge of the closest sealing groove; the hydrogen distribution area adopts a one-to-four flow channel structure, and the arrangement of the three ridges in each one-to-four channel in the hydrogen distribution area is gradient distributed; each ridge of the hydrogen flow field is in contact with the anode diffusion layer; the hydrogen exhaust distribution area of ​​the hydrogen flow field is symmetrical with the center of the hydrogen inlet distribution area; the hydrogen electrochemical reaction active area is provided with a straight flow channel structure.

[0043] In combination with the second aspect, in certain implementations of the second aspect, the flow channel length of the hydrogen inlet zone close to the cooling water inlet channel is smaller than the flow channel length of the hydrogen inlet zone away from the cooling water inlet channel; the flow channel length of the hydrogen inlet zone gradually increases in the direction approaching the hydrogen distribution zone.

[0044] In combination with the second aspect, in certain implementations of the second aspect, the first portion of the flow channel in the hydrogen transition zone is arranged relatively close to the hydrogen gas inlet channel, the first portion of the flow channel in the hydrogen transition zone is arranged relatively to the cooling water inlet channel, and the sealing groove between the first portion of the flow channel in the hydrogen transition zone and the cooling water inlet channel is parallel to the first portion of the flow channel in the hydrogen transition zone; the first portion of the flow channel in the hydrogen transition zone is at an angle of 90° relative to the hydrogen distribution zone;

[0045] The second portion of the flow channel in the hydrogen transition zone extends relatively away from the hydrogen inlet channel; the proximal end of the second portion of the flow channel in the hydrogen transition zone is arranged opposite to the cooling water inlet channel, and the sealing groove between the proximal end of the second portion of the flow channel in the hydrogen transition zone and the cooling water inlet channel remains parallel to the proximal end of the second portion of the flow channel in the hydrogen transition zone; the proximal end of the second portion of the flow channel in the hydrogen transition zone is at an angle of 90° to the hydrogen distribution zone; the distal end of the second portion of the flow channel in the hydrogen transition zone is arranged opposite to the air inlet channel, and the sealing groove between the distal end of the second portion of the flow channel in the hydrogen transition zone and the air inlet channel remains parallel to the distal end of the second portion of the flow channel in the hydrogen transition zone; the distal end of the second portion of the flow channel in the hydrogen transition zone is at an angle of 110° to the hydrogen distribution zone.

[0046] In combination with the second aspect, in certain implementations of the second aspect, the absolute value of the angle formed by the line connecting the centers of the ridge edge circles and the central vertical line in the four flow channels in the hydrogen distribution area ranges from 7° to 29°; the angle formed by the line connecting the centers of the ridge edge circles and the central vertical line first increases and then decreases from bottom to top.

[0047] In conjunction with the second aspect, in certain implementations of the second aspect, the hydrogen flow field satisfies at least one of the following:

[0048] The flow channel of the hydrogen inlet area forms an angle of 90° with the edge of the large hydrogen inlet channel;

[0049] The angle between the hydrogen inlet area and the hydrogen distribution area is 143°;

[0050] The ridge width between two adjacent flow channels in the hydrogen transition zone is 1.32 mm, and the flow channel width is 0.52 mm;

[0051] The ridge width between two adjacent flow channels in the hydrogen inlet area is 1.32 mm, and the flow channel width is 0.52 mm;

[0052] The ridge width in the one-to-four flow channels in the hydrogen distribution area is 0.4 mm;

[0053] The width of the flow channel between two adjacent ridges in the one-to-four flow channel in the hydrogen distribution area is 0.58 mm;

[0054] The ridge width between two adjacent one-to-four flow channels in the hydrogen distribution area is 4.32 mm;

[0055] In the hydrogen distribution area, in the 1st to 4th four-way flow channels from bottom to top, the absolute value of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line is 7°; in the 5th to 8th four-way flow channels from bottom to top, the absolute value of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line is 27°; in the 9th to 10th four-way flow channels from bottom to top, the absolute values ​​of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line are 21° and 29° respectively; the angle between the line connecting the centers of the ridge edges of the 4th four-way flow channel and the line connecting the centers of the ridge edges of the 5th four-way flow channel is 146°.

[0056] On the third aspect, an air electrode plate is provided to form an air flow field of a PEM fuel cell; the air flow field includes an air intake distribution area, an air electrochemical reaction active area and an air exhaust distribution area; the air intake distribution area of ​​the air flow field includes an air intake area, an air transition area and an air distribution area; the flow channel of the air intake area is perpendicular to the edge of the large air intake channel, and all the flow channels in the air transition area are parallel to the edge of the nearest sealing groove; the air distribution area adopts a one-to-four flow channel structure, and the arrangement of the three ridges in each one-to-four channel in the air distribution area is gradient distributed; each ridge on the air flow field side is in contact with the cathode diffusion layer; the air exhaust distribution area of ​​the air flow field is symmetrical with the center of the air intake distribution area; the air electrochemical reaction active area is provided with a flow field structure of a straight flow channel.

[0057] In combination with the third aspect, in certain implementations of the third aspect, the flow channel length of the air intake zone close to the cooling water inlet channel is smaller than the flow channel length of the air intake zone away from the cooling water inlet channel; the flow channel length of the air intake zone gradually increases in the direction approaching the air distribution zone.

[0058] In combination with the third aspect, in some implementations of the third aspect, the first part of the flow channel in the air transition zone is arranged relatively close to the large air intake channel, the first part of the flow channel in the air transition zone is arranged opposite to the large cooling water intake channel, and the sealing groove between the first part of the flow channel in the air transition zone and the large cooling water intake channel is parallel to the first part of the flow channel in the air transition zone; the first part of the flow channel in the air transition zone is at an angle of 90° relative to the air distribution zone;

[0059] The second part of the flow channel in the air transition zone extends relatively far away from the large air intake channel; the proximal end of the second part of the flow channel in the air transition zone is arranged opposite to the large cooling water intake channel, and the sealing groove between the proximal end of the second part of the flow channel in the air transition zone and the large cooling water intake channel remains parallel to the proximal end of the second part of the flow channel in the air transition zone; the proximal end of the second part of the flow channel in the air transition zone is at an angle of 90° to the air distribution zone; the distal end of the second part of the flow channel in the air transition zone is arranged opposite to the large hydrogen intake channel, and the sealing groove between the distal end of the second part of the flow channel in the air transition zone and the large hydrogen intake channel remains parallel to the distal end of the second part of the flow channel in the air transition zone; the distal end of the second part of the flow channel in the air transition zone is at an angle of 127° to the air distribution zone.

[0060] In conjunction with the third aspect, in certain implementations of the third aspect, the air flow field satisfies at least one of the following:

[0061] The angle between the flow channel of the air intake area and the edge of the large air intake channel is 90 degrees;

[0062] The angle between the air intake area and the air distribution area is 160°;

[0063] The ridge width between two adjacent flow channels in the air transition zone is 1.84 mm, and the flow channel width is 1.04 mm;

[0064] The ridge width between two adjacent flow channels in the air intake area is 1.32 mm, and the flow channel width is 0.52 mm;

[0065] The ridge width in the one-to-four flow channels in the air distribution area is 0.4 mm;

[0066] The flow channel width between two adjacent ridges in the one-to-four flow channels in the air distribution area is 0.58 mm;

[0067] The ridge width between two adjacent one-to-four flow channels in the air distribution area is 4.32 mm;

[0068] In the air distribution area, the angle between the center line of the inner ridge edge of the 1st to 2nd four-channel flow channel from bottom to top and the central vertical line is 33°~39°; the angle between the center line of the inner ridge edge of the 3rd to 10th four-channel flow channel from bottom to top and the central vertical line is 12°; the angle between the center line of the inner ridge edge of the 11th four-channel flow channel from bottom to top and the central vertical line is 15°.

[0069] In a fourth aspect, a cooling water plate is provided to form a cooling water flow field of a PEM fuel cell; the cooling water flow field includes a water inlet distribution area, an electrochemical reaction heat exchange area and a drainage distribution area; the water inlet distribution area is divided into a cooling water inlet area and a cooling water distribution area; the angle formed by the flow channel of the cooling water inlet area and the upper edge of the cooling water inlet channel ranges from 0° to 19°; the cooling water distribution area adopts a one-to-four flow channel structure, and the arrangement of the ridges in each one-to-four channel in the cooling water distribution area is gradiently distributed, and the drainage distribution area is symmetrical with the center of the water inlet distribution area; the electrochemical reaction heat exchange area is provided with a straight flow field structure.

[0070] In combination with the fourth aspect, in certain implementations of the fourth aspect, an intermediate extension ridge is provided in the 11th to 13th one-divided-in-four channels from the top to the bottom; the intermediate extension ridge extends from the edge of the ridge toward the cooling water inlet area in the flow channel; the extension angle of the intermediate extension ridge is half of the sum of the inclination angles of the edges on both sides of the one-divided-in-four channels where the intermediate extension ridge is located.

[0071] In combination with the fourth aspect, in certain implementations of the fourth aspect, in the cooling water distribution area, except for the 11th to 13th one-in-four channels from top to bottom, the angle formed by the line connecting the centers of the spine edges of the remaining one-in-four channels and the central vertical line ranges from 23° to 53°, and the angle between the line connecting the centers of the spine edges and the central vertical line from both sides to the middle first decreases and then increases; in terms of the angle between the line connecting the centers of the spine edges and the central vertical line, the 1st to 10th one-in-four channels from bottom to top are symmetrical with the 1st to 10th one-in-four channels from top to bottom.

[0072] In conjunction with the fourth aspect, in certain implementations of the fourth aspect, the cooling water flow field satisfies at least one of the following:

[0073] There are 19 cooling water inlet area flow channels, and the angles formed with the upper edge of the cooling water inlet channel are 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, and 19° from top to bottom;

[0074] From top to bottom, the angles between the line connecting the center of the dorsal edge and the vertical line of the center are 31°, 32°, 33°, 32°, 31°, 30°, 29°, 28°, 49°, and 53° for the 1st to 10th four-channel respectively;

[0075] From top to bottom, the angles of the middle extended ridges in the 11th to 13th one-fourth channel relative to the central vertical line are 63°, 52°, and 48° respectively;

[0076] In the 11th to 13th one-to-four channels from top to bottom, each one-to-four flow channel has extended sharp corner structures on both sides of the middle extended ridge; the arc radius of the upper extended sharp corner structure is 2.42mm, and the arc radius of the lower extended sharp corner structure is 4.08mm.

[0077] In a fifth aspect, a PEM fuel cell is provided, wherein the PEM fuel cell includes a bipolar plate structure as described in any one of the implementations in the first aspect above, or includes a hydrogen electrode plate as described in any one of the implementations in the second aspect above, or includes an air electrode plate as described in any one of the implementations in the third aspect above, or includes a cooling water plate as described in any one of the implementations in the fourth aspect above.

[0078] Compared with the prior art, the solution provided by the present invention includes at least the following beneficial technical effects:

[0079] 1. The smaller flow channel width designed in the transition area of ​​the hydrogen flow field can increase the flow rate of the gas in this area, generate greater disturbances at the junction of the transition area and the distribution area, increase the uniformity of fluid redistribution, and the ridge width between each of the four channels in the hydrogen / air electrochemical active area is designed to be slightly larger than the width of the flow channel. This groove-ridge ratio design structure can further improve the surface conductivity of the bipolar plate while ensuring the uniform distribution of gas, and can also disperse the problem of uneven distribution stress during press-fitting.

[0080] 2. In the flow field of hydrogen and air, all flow channels in the transition zone remain parallel to the sealing grooves of the adjacent hydrogen and cooling water channels, ensuring maximum utilization of the plate area and preventing the plate from being damaged due to long-term stress concentration.

[0081] 3. The distribution area adopts a one-to-four flow channel structure, and the regular structure layout of the ridges in the distribution area can ensure the uniformity of air intake in each flow channel in the active area, effectively solve the problem of uneven gas distribution, and improve the life of the membrane electrode. At the same time, this design can effectively solve the local hot spot problem caused by uneven gas distribution.

[0082] 4. The edge of the cooling water inlet / drainage area is an extension of the edge of the cooling water inlet / drainage channel, which is beneficial to ensure the bonding strength of the plate and prevent the cooling water from washing away the adhesive glue in the inlet and outlet channels.

[0083] 5. The middle extended ridge and extended sharp corner structure design of the cooling water distribution area can effectively guide the flow of cooling water, thereby solving the problem of local heat dissipation failure caused by uneven fluid distribution, thereby improving the life of the membrane electrode.

[0084] 6. In the hydrogen flow field, the flow channel width of the transition zone is set to be smaller than that of the distribution zone, to ensure that a larger disturbance is generated in the intersection and bending area of ​​the two due to the fast flow rate, thereby increasing the uniformity of fluid redistribution.

[0085] 7. The ridge width between each of the four channels in the hydrogen / air electrochemical active area is designed to be no narrower than the flow channel width, and the active area groove ridge ratio range is set to 0.8-1. This design structure further improves the surface conductivity of the bipolar plate while ensuring the uniform distribution of gas.

[0086] 8. In the flow field of hydrogen and air, the inlet channel is perpendicular to the edge of the large inlet channel, and the length of the flow channel gradually increases in the direction close to the active area. This design structure ensures that the reaction gas can evenly flow into each branch channel in the active area.

[0087] 9. In the flow field of hydrogen and air, all flow channels in the transition zone remain parallel to the inner grooves of the sealing grooves of the adjacent hydrogen and cooling water channels, and the bending angle of the flow channels in the transition zone is consistent with the bending angle of the sealing groove, which increases the utilization rate of the plate area and the average distribution of stress.

[0088] 10. In the hydrogen flow field, the distribution area adopts a one-to-four flow channel structure, that is, the single flow channel transitions to four flow channels with the same groove-ridge ratio. There are three ridges in each one-to-four flow channel. The absolute value of the angle formed by the line connecting the centers of the three ridge edges and the central vertical line ranges between 7° and 29°. The angle between the line connecting the centers of the ridge edges and the central vertical line in the one-to-four channel is designed to increase first and then decrease from bottom to top, and the angle change is realized between the 4th and 5th one-to-four flow channels. This angle change can adjust the flow direction of the fluid between each one-to-four flow channel, effectively realize the uniformity of fluid distribution, and increase the mass transfer capacity of the middle low-flow flow channel area.

[0089] 11. In the air flow field, the distribution area also adopts a one-to-four flow channel structure, that is, the single flow channel transitions to four flow channels with the same groove-ridge ratio. There are three ridges in each one-to-four flow channel, and the absolute value of the angle formed by the line connecting the center of the ridge edge and the central vertical line ranges from 12° to 39°. The angle between the line connecting the center of the ridge edge and the central vertical line in the one-to-four flow channel in the middle area of ​​the flow field is designed to be consistent, thereby enhancing the disturbance of the low flow area in the middle flow channel.

[0090] 12. In the cooling water flow field, the distribution area adopts a one-to-four flow channel structure. To ensure the consistency of the fluid flow resistance in each flow channel, an intermediate extension ridge design is added to the 11th to 13th flow channels, and the extension angle is half of the angle sum of the two adjacent flow channels. This design guides the flow of cooling water, solves the problem of uneven flow distribution in a single flow channel in the middle flow field, avoids the generation of local hot spots, and improves the consistency of membrane electrode temperature distribution.

[0091] 13. The flow channel in the cooling water inlet / drainage distribution area is a co-directional extension of the edge of the cooling water inlet / drainage channel. Compared with the traditional non-extension design, this solution effectively prevents the cooling water flow from impacting the plate sealing area and causing seal failure, which can extend the life of the bipolar plate and fuel cell stack.

[0092] 14. In the transition area to the junction area of ​​the cooling water flow field, an extended sharp angle structure is used at the beginning of the two middle ridges in each one-to-four flow channel to guide the cooling water into the middle low-flow flow channel, playing a role in fluid regulation and distribution.

[0093] 15. In the cooling water flow field, except for the three one-to-four channels in the middle, the angle formed by the line connecting the center of the ridge edge of the remaining one-to-four channels and the central vertical line is between 23° and 43°. The angle first decreases and then increases from the two sides to the middle. At the same time, the ridges on the left and right sides are designed to be mirror-image symmetrical to achieve consistency in the water flow on both sides of the electrochemical reaction heat exchange area. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 This is a schematic diagram of the hydrogen electrode plate of a PEM fuel cell provided by the present invention.

[0095] Figure 2A for Figure 1 A partial enlarged view of middle A.

[0096] Figure 2B This is a partial structural diagram of the hydrogen intake distribution area.

[0097] Figure 2C This is a partial structural diagram of the hydrogen intake distribution area.

[0098] Figure 2D Schematic diagram of the flow channel and spine structure.

[0099] Figure 3 This is a schematic diagram of the air flow field plate structure of a PEM fuel cell provided by the present invention.

[0100] Figure 4A for Figure 3 A partial enlarged view of B.

[0101] Figure 4B This is a partial structural diagram of the air intake distribution area.

[0102] Figure 4C This is a partial structural diagram of the air intake distribution area.

[0103] Figure 5 This is a schematic diagram of the structure of the cooling water flow field plate of the PEM fuel cell provided by the present invention.

[0104] Fig. 6A for Figure 5 A partial enlarged view of C in the middle.

[0105] Figure 6B for Fig. 6A A partial enlarged view of D in the middle.

[0106] Figure 6C This is the local structural diagram of the cooling water inlet area.

[0107] Fig.6D This is a partial structural diagram of the cooling water distribution area.

[0108] Figure 7 A schematic diagram of a fuel cell. DETAILED DESCRIPTION

[0109] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0110] The present invention provides a bipolar plate structure for realizing a flow field distribution area, and the bipolar plate structure can be applied to a PEM fuel cell. The bipolar plate structure includes: an air-water plate (the front and back sides are respectively an air flow field and a cooling water flow field) and a hydrogen plate, and the two are bonded to form a set of bipolar plate structures. A hydrogen gas inlet channel 1, an air gas inlet channel 2, and a cooling water inlet channel 3 are provided on the first side of the bipolar plate structure, and the cooling water inlet channel 3 is located between the hydrogen gas inlet channel 1 and the air gas inlet channel 2. A hydrogen gas exhaust channel 4, an air gas exhaust channel 5, and a cooling water drainage channel 6 are provided on the second side of the bipolar plate structure, and the cooling water drainage channel 6 is located between the hydrogen gas exhaust channel 4 and the air gas exhaust channel 5. The hydrogen gas inlet channel 1 and the hydrogen gas exhaust channel 4 are symmetrical in center. The air gas inlet channel 2 and the air gas exhaust channel 5 are symmetrical in center. The cooling water inlet channel 3 and the cooling water drainage channel 6 are symmetrical in center.

[0111] In order to ensure the uniformity of hydrogen and air distribution in the flow field, the present invention divides the bipolar plate flow field air intake distribution area into three parts, namely the air intake area, the transition area and the distribution area. The air intake area flow channel is perpendicular to the edge of the large air intake channel, and all the flow channels in the transition area are parallel to the edge of the sealing groove. After turning to the distribution area, a one-to-four flow channel structure is adopted. The arrangement of the ridges in each one-to-four channel in the distribution area is gradient distributed. At the same time, the extension design of the ridges in a specific area is used to ensure the uniform distribution of hydrogen and air in the flow field. The exhaust distribution area has the same structure as the air intake distribution area.

[0112] The present invention divides the cooling water flow field water inlet distribution area into two parts, namely the cooling water inlet area and the cooling water distribution area. The angle formed by the cooling water inlet area flow channel and the upper edge of the cooling water inlet channel is between 0° and 19°. After turning to the distribution area, a one-to-four flow channel structure is adopted, and the extended sharp angle design of the ridge of the specific area is used to ensure the uniform distribution of cooling water in the flow field. The drainage distribution area has the same structure as the water inlet distribution area and is distributed symmetrically according to the center.

[0113] Figure 1 A hydrogen electrode plate provided by the present application is shown. The overall shape of the hydrogen electrode plate is a rectangular structure, and a hydrogen flow field is formed in the central area of ​​the hydrogen electrode plate. The hydrogen flow field formed by the hydrogen electrode plate includes a hydrogen inlet distribution area 7, a hydrogen electrochemical reaction active area 8, and a hydrogen exhaust distribution area 9. The hydrogen inlet distribution area 7 and the hydrogen exhaust distribution area 9 are arranged according to central symmetry. The hydrogen electrochemical reaction active area 8 is provided with a flow field structure of a straight flow channel.

[0114] FIG. 2A to FIG. 2C Shown Figure 1 A partial enlarged view of the hydrogen gas inlet distribution area 7 in the hydrogen plate. The hydrogen gas inlet distribution area 7 includes three parts, namely the hydrogen gas inlet area 10, the hydrogen gas transition area 11 and the hydrogen gas distribution area 12.

[0115] The flow channel of the hydrogen inlet area 10 is at an angle of 90° to the edge of the hydrogen inlet channel 1. The length of the flow channel of the hydrogen inlet area 10 close to the cooling water inlet channel 3 is less than the length of the flow channel of the hydrogen inlet area 10 away from the cooling water inlet channel 3. The length of the flow channel of the hydrogen inlet area 10 gradually increases in the direction close to the hydrogen distribution area 12. The angle between the hydrogen inlet area 10 and the hydrogen distribution area 12 is 143°, reference Figure 2B The hydrogen enters the hydrogen transition zone 11 through the hydrogen inlet zone 10 and the curved flow channel. All the flow channels of the hydrogen transition zone 11 are parallel to the closest sealing groove 13.

[0116] For example, part of the hydrogen transition zone 11 is relatively close to the hydrogen inlet channel 1, and this part of the hydrogen transition zone 11 is arranged opposite to the cooling water inlet channel 3. Then the sealing groove 13 between the hydrogen transition zone 11 and the cooling water inlet channel 3 remains parallel to this part of the hydrogen transition zone 11; this part of the hydrogen transition zone 11 can be at an angle of 90° relative to the hydrogen distribution zone 12.

[0117] For another example, there is a portion of the hydrogen transition zone 11 extending relatively far from the hydrogen gas inlet channel 1, so the length of this portion of the hydrogen transition zone 11 is relatively long. The proximal end of the hydrogen transition zone 11 is arranged opposite to the cooling water inlet channel 3, and the sealing groove 13 between the proximal end of the hydrogen transition zone 11 and the cooling water inlet channel 3 remains parallel to the proximal end of the hydrogen transition zone 11; the proximal end of the hydrogen transition zone 11 can be at an angle of 90° relative to the hydrogen distribution zone 12. The distal end of the hydrogen transition zone 11 is arranged opposite to the air gas inlet channel 2, and the sealing groove 13 between the distal end of the hydrogen transition zone 11 and the air gas inlet channel 2 remains parallel to the distal end of the hydrogen transition zone 11; the distal end of the hydrogen transition zone 11 can be at an angle of 110° relative to the hydrogen distribution zone 12, refer to Figure 2B .

[0118] In order to ensure that the intersection of the hydrogen transition zone 11 and the hydrogen distribution zone 12 generates a large disturbance due to the fast flow rate, and increase the uniformity of fluid redistribution, reference Figure 2B The ridge width between the two hydrogen transition zone 11 flow channels is designed to be 1.32 mm, and the flow channel width is designed to be 0.52 mm. The ridge width between the two hydrogen inlet zone 10 flow channels can be correspondingly set to 1.32 mm, and the flow channel width can be correspondingly set to 0.52 mm.

[0119] After the hydrogen is transferred to the hydrogen distribution area 12, a one-to-four flow channel structure is adopted, which transitions from a single flow channel to four flow channels with the same groove-ridge ratio, and each one-to-four flow channel has three ridges, such as Figure 2D Reference Figure 2B The ridge width of the one-to-four flow channel in the hydrogen distribution area 12 is 0.4 mm, the flow channel width is 0.58 mm, and the large ridge width between two adjacent one-to-four flow channels is 4.32 mm. This design further improves the surface conductivity of the bipolar plate. Each ridge of the hydrogen plate is attached to the anode diffusion layer.

[0120] refer to Figure 2C, the absolute value of the angle formed by the connecting line of the center of the three ridge edges and the central vertical line in the one-point four-channel structure ranges between 7° and 29°, for example, the value is 7°, 21°, 27° or 29°. In order to achieve uniformity of fluid distribution and increase the mass transfer capacity of the middle low-flow channel area, the angle between the connecting line of the center of the ridge edge and the central vertical line in the one-point four-channel is designed to increase first and then decrease from bottom to top. Among them, a part of the hydrogen transition zone 11 is relatively close to the hydrogen intake channel 1, and the absolute value of the angle formed by the connecting line of the center of the ridge edge and the central vertical line in the one-point four-channel hydrogen distribution area 12 connected to this part (for example, the 5th to 10th one-point four-channel from bottom to top) can be 21°, 27° or 29°. There is also a part of the hydrogen transition zone 11 extending relatively far away from the hydrogen intake channel 1, and the far end of the hydrogen transition zone 11 is arranged relative to the air intake channel 2. In the four-channel hydrogen distribution area 12 connected to the far end of the hydrogen transition area 11 (for example, the 1st to 4th four-channels from bottom to top), the absolute value of the angle formed by the line connecting the center of the back edge and the center vertical line can be 7°. The angle between the line connecting the center of the back edge of the 4th four-channel and the line connecting the center of the back edge of the 5th four-channel is 146°.

[0121] The hydrogen inlet distribution area 7 and the hydrogen exhaust distribution area 9 have the same structure and are arranged symmetrically with respect to the center point of the hydrogen electrochemical reaction active area 8 .

[0122] Figure 3 The air flow field of an air-water plate is shown. The overall shape of the air-water plate is a rectangular structure, and the air flow field formed includes: an air intake distribution area 14, an air electrochemical reaction active area 15, and an air exhaust distribution area 16. The air intake distribution area 14 and the air exhaust distribution area 16 are arranged according to central symmetry. The air electrochemical reaction active area 15 is provided with a flow field structure of a straight channel.

[0123] FIG. 4A to FIG. 4C Shown Figure 3 A partial enlarged view of the air intake distribution area 14 in the air-water plate. The air intake distribution area 14 includes three parts, namely, the air intake area 17, the air transition area 18 and the air distribution area 19.

[0124] The flow channel of the air intake area 17 is at an angle of 90 degrees to the edge of the large air intake channel 2. The length of the flow channel of the air intake area 17 close to the large cooling water inlet channel 3 is less than the length of the flow channel of the air intake area 17 away from the large cooling water inlet channel 3. The flow channel length of the air intake area 17 gradually increases in the direction close to the air distribution area 19. The angle between the air intake area 17 and the air distribution area 19 is 160 degrees, referring to Figure 4B The air enters the air transition zone 18 through the air inlet zone 17 and the bending design. All the flow channels of the air transition zone 18 are parallel to the closest sealing groove 13.

[0125] For example, part of the air transition zone 18 is relatively close to the air intake channel 2, and this part of the air transition zone 18 is arranged opposite to the cooling water inlet channel 3. Then the sealing groove 13 between the air transition zone 18 and the cooling water inlet channel 3 remains parallel to this part of the air transition zone 18; this part of the air transition zone 18 can be at an angle of 90° relative to the air distribution zone 19.

[0126] For another example, there is a portion of the air transition zone 18 extending relatively far from the air intake passage 2, so the length of this portion of the air transition zone 18 is relatively long. The proximal end of the air transition zone 18 is arranged opposite to the cooling water intake passage 3, and the sealing groove 13 between the proximal end of the air transition zone 18 and the cooling water intake passage 3 remains parallel to the proximal end of the air transition zone 18; the proximal end of the air transition zone 18 can be at an angle of 90° relative to the air distribution zone 19. The distal end of the air transition zone 18 is arranged opposite to the hydrogen intake passage 1, and the sealing groove 13 between the distal end of the air transition zone 18 and the hydrogen intake passage 1 remains parallel to the distal end of the air transition zone 18; the distal end of the air transition zone 18 can be at an angle of 127° relative to the air distribution zone 19, refer to Figure 4B .

[0127] In order to ensure that the intersection of the air transition zone 18 and the air distribution zone 19 generates greater disturbance due to the fast flow rate and increase the uniformity of fluid redistribution, reference Figure 4B The ridge width between the two air transition zone 18 flow channels is designed to be 1.84 mm, and the flow channel width is 1.04 mm. The ridge width between the two air inlet zone 17 flow channels can be set to 1.32 mm, and the flow channel width can be set to 0.52 mm.

[0128] After the air is transferred to the air distribution area 19, a one-to-four flow channel structure is adopted, which transitions from a single flow channel to four flow channels with the same groove-ridge ratio, and each one-to-four flow channel has three ridges. Figure 4B The ridge width of the one-to-four flow channel in the air distribution area 19 is 0.4mm, the flow channel width is 0.58mm, and the large ridge width between two adjacent one-to-four flow channels is 4.32mm. This design further improves the surface conductivity of the bipolar plate. The ridges of the air-water plate on the air flow field side are attached to the cathode diffusion layer.

[0129] refer to Figure 4C, the absolute value of the angle formed by the connecting line of the centers of the three ridge edges in the one-divided four-channel structure and the central vertical line ranges between 12° and 39°, for example, the value is 12°, 15°, 33° or 39°. The design idea of ​​the one-divided four-channel structure in the air plate refers to the one-divided four-channel structure of the hydrogen plate. Considering the reason for increasing the disturbance of the air flow in the middle channel area of ​​the air electrochemical reaction active area 15, on the basis of the original design, the angle between the connecting line of the centers of the ridge edges in the 1st to 2nd one-divided four-channel from bottom to top and the central vertical line is designed to be 33°~39°. The angle between the connecting line of the centers of the ridge edges in the 3rd to 10th one-divided four-channel from bottom to top and the central vertical line is 12°. The angle between the connecting line of the centers of the ridge edges in the 11th one-divided four-channel from bottom to top and the central vertical line is 15°.

[0130] The air intake distribution area 14 and the air exhaust distribution area 16 have the same structure and are arranged symmetrically with respect to the center point of the air electrochemical reaction active area 15. Except for the intake / exhaust distribution area, the air flow field and the hydrogen flow field have the same structural design.

[0131] Figure 5 The cooling water flow field of an empty water plate is shown. The cooling water flow field includes: an inlet distribution area 20, an electrochemical reaction heat exchange area 21, and a drainage distribution area 22. The inlet distribution area 20 and the drainage distribution area 22 are arranged according to central symmetry, and the electrochemical reaction heat exchange area 21 is provided with a straight flow field structure.

[0132] like Fig. 6A As shown, the present invention divides the cooling water flow field water inlet distribution area 20 into two parts, namely the cooling water inlet area 23 and the cooling water distribution area 24. In order to ensure the bonding strength of the plate and prevent the cooling water from washing away the adhesive glue when entering the inlet and outlet channels, the edge of the cooling water inlet area 23 is an extension of the edge of the cooling water inlet channel 3. The angle formed by the flow channel of the cooling water inlet area 23 and the upper edge of the cooling water inlet channel 3 is in the range of 0°-19°. Figure 6C As shown, there are 19 flow channels in the cooling water inlet area 23, and the angles formed with the upper edge of the cooling water inlet channel 3 are 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, and 19° from top to bottom.

[0133] After the cooling water is transferred to the cooling water distribution area 24, a one-to-four flow channel structure is adopted. In the cooling water distribution area 24, except for the 11th to 13th one-to-four channels from top to bottom, the angle formed by the line connecting the center of the back edge of the remaining one-to-four channels and the central vertical line is between 23° and 53°. The backs on both sides are mirror-image symmetrical. In other words, the 1st to 10th one-to-four channels from bottom to top are symmetrically designed with the 1st to 10th one-to-four channels from top to bottom in terms of the angle between the line connecting the center of the back edge and the central vertical line.

[0134] In addition, the angle between the line connecting the centers of the edges of the spine and the vertical line from both sides to the middle first decreases and then increases. The smallest angle between the line connecting the centers of the edges of the spine and the vertical line is the 8th from top to bottom (or the 8th from bottom to top), and the minimum angle is 28°. The largest angle between the line connecting the centers of the edges of the spine and the vertical line is the 10th from top to bottom (or the 10th from bottom to top), and the maximum angle is 53°. From top to bottom, the 1st to the 10th channels are divided into four channels, and the angles between the line connecting the centers of the edges of the spine and the vertical line are 31°, 32°, 33°, 32°, 31°, 30°, 29°, 28°, 49°, and 53°, respectively.

[0135] Figure 6B The figure shows a partial enlarged view of the middle section of the cooling water distribution area 24. The design of the middle extension ridge 25 is added in the 11th to 13th one-to-four channels from the top to the bottom. The middle extension ridge 25 extends from the edge of the ridge in the flow channel toward the cooling water inlet area 23. The extension angle of the middle extension ridge 25 is half of the sum of the inclination angles of the edges on both sides of the one-to-four channels where the middle extension ridge 25 is located. Fig.6D As shown, the included angles of the middle extended ridge 25 in the 11th to 13th one-to-four channels from top to bottom relative to the central vertical line are 63°, 52°, and 48° respectively. In the 11th to 13th one-to-four channels from top to bottom, each one-to-four flow channel has an extended sharp angle structure 26 added on both sides of the middle extended ridge 25. The arc radius of the upper side extended sharp angle structure 26 is 2.42 mm, and the arc radius of the lower side extended sharp angle structure 26 is 4.08 mm.

[0136] In summary, the present invention provides a fuel cell graphite bipolar plate structural design, which is based on the flow channel optimization design of the hydrogen flow field, the inlet / exhaust distribution area of ​​the air flow field, and the inlet / exhaust distribution area of ​​the cooling water flow field, and is of great significance for improving the performance of PEM fuel cells in practical applications.

[0137] like Figure 7 As shown, the present invention also provides a fuel cell. The fuel cell includes a hydrogen first plate, an air last plate and the bipolar plate structure described above, and the number of bipolar plate structures can be multiple. The hydrogen first plate is a kind of hydrogen plate, and its hydrogen flow field can refer to the hydrogen flow field of the hydrogen plate of the bipolar plate structure. The hydrogen first plate is set to face the air flow field of the air-water plate of its most adjacent bipolar plate structure. The air last plate is a kind of air plate, and its air flow field can refer to the air flow field of the bipolar plate structure. The air last plate is set to face the hydrogen flow field of the hydrogen plate of its most adjacent bipolar plate structure.

[0138] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.

Claims

1. A bipolar plate structure for realizing a flow field distribution zone, characterized in that: It includes an air-water plate and a hydrogen plate, which are bonded to form a set of bipolar plate structure; the hydrogen plate forms the hydrogen flow field of the PEM fuel cell, and the front and back sides of the air-water plate are the air flow field and cooling water flow field of the PEM fuel cell respectively; the cooling water flow field is located between the hydrogen flow field and the air flow field; A large hydrogen inlet channel (1), a large air inlet channel (2), and a large cooling water inlet channel (3) are provided on the first side of the bipolar plate structure, and the large cooling water inlet channel (3) is located between the large hydrogen inlet channel (1) and the large air inlet channel (2); The second side of the bipolar plate structure is provided with a hydrogen exhaust channel (4), an air exhaust channel (5), and a cooling water drainage channel (6), wherein the cooling water drainage channel (6) is located between the hydrogen exhaust channel (4) and the air exhaust channel (5); the hydrogen intake channel (1) and the hydrogen exhaust channel (4) are centrally symmetrical; the air intake channel (2) and the air exhaust channel (5) are centrally symmetrical; the cooling water intake channel (3) and the cooling water drainage channel (6) are centrally symmetrical; and the bipolar plate structure satisfies at least one of the following conditions: The hydrogen flow field comprises a hydrogen inlet distribution area (7), a hydrogen electrochemical reaction active area (8) and a hydrogen exhaust distribution area (9); the hydrogen inlet distribution area (7) of the hydrogen flow field comprises a hydrogen inlet area (10), a hydrogen transition area (11) and a hydrogen distribution area (12); the flow channel of the hydrogen inlet area (10) is perpendicular to the edge of the hydrogen inlet large channel (1), and all the flow channels of the hydrogen transition area (11) are parallel to the edge of the closest sealing groove (13); the hydrogen distribution area (12) adopts a one-to-four flow channel structure, and the arrangement of three ridges in each one-to-four channel in the hydrogen distribution area (12) is gradient distributed; each ridge of the hydrogen flow field is in contact with the anode diffusion layer; the hydrogen exhaust distribution area (9) of the hydrogen flow field is symmetrical with the center of the hydrogen inlet distribution area (7); the hydrogen electrochemical reaction active area (8) is provided with a flow field structure of a straight channel; The air flow field comprises an air intake distribution area (14), an air electrochemical reaction active area (15) and an air exhaust distribution area (16); the air intake distribution area (14) of the air flow field comprises an air intake area (17), an air transition area (18) and an air distribution area (19); the flow channel of the air intake area (17) is perpendicular to the edge of the large air intake channel (2), and all the flow channels of the air transition area (18) are parallel to the edge of the closest sealing groove (13); the air distribution area (19) adopts a one-to-four flow channel structure, and the arrangement of three ridges in each one-to-four channel in the air distribution area (19) is gradient distributed; each ridge on the air flow field side is in contact with the cathode diffusion layer; the air exhaust distribution area (16) of the air flow field is symmetrical with the center of the air intake distribution area (14); the air electrochemical reaction active area (15) is provided with a flow field structure of a straight flow channel; The cooling water flow field comprises a water inlet distribution area (20), an electrochemical reaction heat exchange area (21) and a drainage distribution area (22); the water inlet distribution area (20) is divided into a cooling water inlet area (23) and a cooling water distribution area (24); the angle formed by the flow channel of the cooling water inlet area (23) and the upper edge of the cooling water inlet large channel (3) ranges from 0° to 19°; the cooling water distribution area (24) adopts a one-to-four flow channel structure, the arrangement of the ridges in each one-to-four channel in the cooling water distribution area (24) is gradient distributed, and the drainage distribution area (22) is symmetrical with the center of the water inlet distribution area (20); the electrochemical reaction heat exchange area (21) is provided with a straight channel flow field structure.

2. The bipolar plate structure according to claim 1, characterized in that: The length of the flow channel of the hydrogen inlet area (10) close to the cooling water inlet channel (3) is shorter than the length of the flow channel of the hydrogen inlet area (10) away from the cooling water inlet channel (3); and the length of the flow channel of the hydrogen inlet area (10) gradually increases in a direction close to the hydrogen distribution area (12).

3. The bipolar plate structure according to claim 1, characterized in that: The first part of the flow channel of the hydrogen transition zone (11) is arranged relatively close to the hydrogen inlet channel (1), the first part of the flow channel of the hydrogen transition zone (11) is arranged relatively to the cooling water inlet channel (3), and the sealing groove (13) between the first part of the flow channel of the hydrogen transition zone (11) and the cooling water inlet channel (3) is kept parallel to the first part of the flow channel of the hydrogen transition zone (11); the first part of the flow channel of the hydrogen transition zone (11) is at an angle of 90° relative to the hydrogen distribution zone (12); The second part of the flow channel of the hydrogen transition zone (11) extends relatively far from the hydrogen gas inlet channel (1); the proximal end of the second part of the flow channel of the hydrogen transition zone (11) is arranged opposite to the cooling water inlet channel (3), and the sealing groove (13) between the proximal end of the second part of the flow channel of the hydrogen transition zone (11) and the cooling water inlet channel (3) remains parallel to the proximal end of the second part of the flow channel of the hydrogen transition zone (11); the proximal end of the second part of the flow channel of the hydrogen transition zone (11) is at an angle of 90° relative to the hydrogen distribution zone (12); the distal end of the second part of the flow channel of the hydrogen transition zone (11) is arranged opposite to the air inlet channel (2), and the sealing groove (13) between the distal end of the second part of the flow channel of the hydrogen transition zone (11) and the air inlet channel (2) remains parallel to the distal end of the second part of the flow channel of the hydrogen transition zone (11); the distal end of the second part of the flow channel of the hydrogen transition zone (11) is at an angle of 110° relative to the hydrogen distribution zone (12).

4. The bipolar plate structure according to claim 1, characterized in that: The absolute value of the angle formed by the line connecting the center of the ridge edge circle and the central vertical line in the four flow channels of the hydrogen distribution area (12) ranges from 7° to 29°; the angle formed by the line connecting the center of the ridge edge circle and the central vertical line increases first and then decreases from bottom to top.

5. The bipolar plate structure according to any one of claims 1 to 4, characterized in that: The hydrogen flow field satisfies at least one of the following: The flow channel of the hydrogen inlet area (10) and the edge of the large hydrogen inlet channel (1) form an angle of 90°; The angle between the hydrogen inlet area (10) and the hydrogen distribution area (12) is 143°; The ridge width between two adjacent flow channels in the hydrogen transition zone (11) is 1.32 mm, and the flow channel width is 0.52 mm; The ridge width between two adjacent flow channels in the hydrogen inlet area (10) is 1.32 mm, and the flow channel width is 0.52 mm; The ridge width of the one-to-four flow channels in the hydrogen distribution area (12) is 0.4 mm; The width of the flow channel between two adjacent ridges in the one-to-four flow channels in the hydrogen distribution area (12) is 0.58 mm; The ridge width between two adjacent one-dividing four-flow channels in the hydrogen distribution area (12) is 4.32 mm; In the hydrogen distribution area (12), in the 1st to 4th four-way flow channels from bottom to top, the absolute value of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line is 7°; in the 5th to 8th four-way flow channels from bottom to top, the absolute value of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line is 27°; in the 9th to 10th four-way flow channels from bottom to top, the absolute values ​​of the angle formed by the line connecting the centers of the ridge edge circle and the central vertical line are 21° and 29° respectively; the angle between the line connecting the centers of the ridge edge circle of the 4th four-way flow channel and the line connecting the centers of the ridge edge circle of the 5th four-way flow channel is 146°.

6. The bipolar plate structure according to claim 1, characterized in that: The length of the flow channel of the air intake area (17) close to the cooling water inlet channel (3) is shorter than the length of the flow channel of the air intake area (17) away from the cooling water inlet channel (3); the length of the flow channel of the air intake area (17) gradually increases in a direction close to the air distribution area (19).

7. The bipolar plate structure according to claim 1, characterized in that: The first part of the flow channel of the air transition zone (18) is arranged relatively close to the large air inlet channel (2), the first part of the flow channel of the air transition zone (18) is arranged relatively to the large cooling water inlet channel (3), the sealing groove (13) between the first part of the flow channel of the air transition zone (18) and the large cooling water inlet channel (3) is kept parallel to the first part of the flow channel of the air transition zone (18); the first part of the flow channel of the air transition zone (18) is at an angle of 90° relative to the air distribution zone (19); The second part of the flow channel of the air transition zone (18) extends relatively far from the large air intake channel (2); the proximal end of the second part of the flow channel of the air transition zone (18) is arranged opposite to the large cooling water intake channel (3), and the sealing groove (13) between the proximal end of the second part of the flow channel of the air transition zone (18) and the large cooling water intake channel (3) remains parallel to the proximal end of the second part of the flow channel of the air transition zone (18); the proximal end of the second part of the flow channel of the air transition zone (18) is at an angle of 90° relative to the air distribution zone (19); the distal end of the second part of the flow channel of the air transition zone (18) is arranged opposite to the large hydrogen intake channel (1), and the sealing groove (13) between the distal end of the second part of the flow channel of the air transition zone (18) and the large hydrogen intake channel (1) remains parallel to the distal end of the second part of the flow channel of the air transition zone (18); the distal end of the second part of the flow channel of the air transition zone (18) is at an angle of 127° relative to the air distribution zone (19).

8. The bipolar plate structure according to any one of claims 1, 6 and 7, characterized in that: The air flow field satisfies at least one of the following: The angle between the flow channel of the air intake area (17) and the edge of the large air intake channel (2) is 90 degrees; The angle between the air intake area (17) and the air distribution area (19) is 160°; The ridge width between two adjacent flow channels in the air transition zone (18) is 1.84 mm, and the flow channel width is 1.04 mm; The ridge width between two adjacent flow channels in the air inlet area (17) is 1.32 mm, and the flow channel width is 0.52 mm; The ridge width of the one-to-four flow channels in the air distribution area (19) is 0.4 mm; The width of the flow channel between two adjacent ridges in the one-to-four flow channels in the air distribution area (19) is 0.58 mm; The ridge width between two adjacent one-dividing four-flow channels in the air distribution area (19) is 4.32 mm; In the air distribution area (19), the angle between the center line of the inner ridge edge of the first to second four-channel flow passages from bottom to top and the central vertical line is 33° to 39°; the angle between the center line of the inner ridge edge of the third to tenth four-channel flow passages from bottom to top and the central vertical line is 12°; the angle between the center line of the inner ridge edge of the eleventh four-channel flow passage from bottom to top and the central vertical line is 15°.

9. The bipolar plate structure according to claim 1, characterized in that: The 11th to 13th one-to-four channels from top to bottom are all provided with a middle extension ridge (25); the middle extension ridge (25) extends from the edge of the ridge toward the cooling water inlet area (23) in the flow channel; the extension angle of the middle extension ridge (25) is half of the sum of the inclination angles of the edges on both sides of the one-to-four channel where the middle extension ridge (25) is located.

10. The bipolar plate structure according to claim 9, characterized in that: In the cooling water distribution area (24), except for the 11th to 13th one-to-four channels from top to bottom, the angle formed by the connecting line of the center of the back edge circle and the central vertical line of the remaining one-to-four channels ranges from 23° to 53°, and the angle formed by the connecting line of the center of the back edge circle and the central vertical line from both sides to the middle first decreases and then increases; in terms of the angle formed by the connecting line of the center of the back edge circle and the central vertical line, the 1st to 10th one-to-four channels from bottom to top are symmetrical with the 1st to 10th one-to-four channels from top to bottom.

11. The bipolar plate structure according to claim 9 or 10, characterized in that: The cooling water flow field meets at least one of the following conditions: There are 19 flow channels in the cooling water inlet area (23), and the angles formed with the upper edge of the cooling water inlet channel (3) are 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, and 19° from top to bottom respectively; From top to bottom, the angles between the line connecting the center of the dorsal edge and the vertical line of the center are 31°, 32°, 33°, 32°, 31°, 30°, 29°, 28°, 49°, and 53° for the 1st to 10th four-channel respectively; The angles of the middle extending ridge (25) in the 11th to 13th one-fourth channel from top to bottom relative to the central vertical line are 63°, 52°, and 48° respectively; In the 11th to 13th one-to-four channels from top to bottom, each one-to-four flow channel has an extended sharp corner structure (26) added on both sides of the middle extended ridge (25); the arc radius of the upper extended sharp corner structure (26) is 2.42 mm, and the arc radius of the lower extended sharp corner structure (26) is 4.08 mm.

12. A hydrogen electrode plate, characterized in that: A hydrogen flow field of a PEM fuel cell is formed; the hydrogen flow field comprises a hydrogen inlet distribution area (7), a hydrogen electrochemical reaction active area (8) and a hydrogen exhaust distribution area (9); the hydrogen inlet distribution area (7) of the hydrogen flow field comprises a hydrogen inlet area (10), a hydrogen transition area (11) and a hydrogen distribution area (12); the flow channel of the hydrogen inlet area (10) is perpendicular to the edge of the hydrogen inlet large channel (1), and all the flow channels of the hydrogen transition area (11) are parallel to the edge of the closest sealing groove (13); the hydrogen distribution area (12) adopts a one-to-four flow channel structure, and the arrangement of three ridges in each one-to-four channel in the hydrogen distribution area (12) is gradient distributed; each ridge of the hydrogen flow field is in contact with the anode diffusion layer; the hydrogen exhaust distribution area (9) of the hydrogen flow field is symmetrical with the center of the hydrogen inlet distribution area (7); and the hydrogen electrochemical reaction active area (8) is provided with a flow field structure of a straight channel.

13. An air plate, characterized in that: An air flow field of a PEM fuel cell is formed; the air flow field comprises an air intake distribution area (14), an air electrochemical reaction active area (15) and an air exhaust distribution area (16); the air intake distribution area (14) of the air flow field comprises an air intake area (17), an air transition area (18) and an air distribution area (19); the flow channel of the air intake area (17) is perpendicular to the edge of the large air intake channel (2), and all the flow channels of the air transition area (18) are parallel to the edge of the closest sealing groove (13); the air distribution area (19) adopts a one-to-four flow channel structure, and the arrangement of three ridges in each one-to-four channel in the air distribution area (19) is gradient distributed; each ridge on the air flow field side is in contact with the cathode diffusion layer; the air exhaust distribution area (16) of the air flow field is symmetrical with the center of the air intake distribution area (14); and the air electrochemical reaction active area (15) is provided with a flow field structure of a straight flow channel.

14. A cooling water plate, characterized in that: A cooling water flow field of a PEM fuel cell is formed; the cooling water flow field comprises a water inlet distribution area (20), an electrochemical reaction heat exchange area (21) and a drainage distribution area (22); the water inlet distribution area (20) is divided into a cooling water inlet area (23) and a cooling water distribution area (24); the angle formed by the flow channel of the cooling water inlet area (23) and the upper edge of the cooling water inlet large channel (3) is in the range of 0°-19°; the cooling water distribution area (24) adopts a one-to-four flow channel structure, the arrangement of the ridges in each one-to-four channel in the cooling water distribution area (24) is gradient distributed, and the drainage distribution area (22) is symmetrical with the center of the water inlet distribution area (20); the electrochemical reaction heat exchange area (21) is provided with a flow field structure of a straight channel.

15. A PEM fuel cell, characterized in that: The PEM fuel cell comprises the bipolar plate structure as claimed in any one of claims 1 to 11, or comprises the hydrogen polar plate as claimed in claim 12, or comprises the air polar plate as claimed in claim 13, or comprises the cooling water plate as claimed in claim 15.

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