Fuel cell flow field inlet and outlet arrangement structure, fuel cell and system

Abstract

The present application provides a flow field inlet and outlet arrangement structure of a fuel cell, a fuel cell and a system, wherein the flow field inlet and outlet arrangement structure of the fuel cell includes: an electrode plate, a reaction zone, a first channel portion and a second channel portion arranged on the electrode plate at both ends of the reaction zone, and a transverse flow field located in the reaction zone and connecting the first channel portion and the second channel portion; wherein the first channel portion includes a cathode inlet, a coolant inlet, and an anode outlet arranged in sequence from top to bottom; and the second channel portion includes a coolant outlet, an anode inlet, and a cathode outlet arranged in sequence from top to bottom. The present invention greatly simplifies the fuel cell structure required for simultaneously realizing the upward exhaust of the coolant flow field outlet and the downward drainage of the gas flow field outlet through the asymmetric layout of each flow field inlet and outlet.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a flow field inlet and outlet arrangement structure of a fuel cell, a fuel cell and a system. Background Art

[0002] Fuel cells convert chemical energy into electrical energy through electrode reactions and are a clean energy source with great potential. High-power fuel cells require a large amount of hydrogen to react with air, so they generate a lot of heat and require a large amount of coolant for temperature control. It is easy for the coolant to mix with tiny bubbles and cannot be discharged, affecting the heat dissipation effect; and the reaction generates a large amount of water, generating a large amount of condensed water, which easily causes the reaction tail gas to be blocked by the condensed water and affect the exhaust effect.

[0003] In order to evenly disperse the gas and coolant into the corresponding flow field area, most existing fuel cell designs adopt a symmetrical design of the flow field inlet and outlet layout. For example, as described in the abstract of the Chinese patent document with the authorization announcement number CN112615021B, the patent provides a symmetrical fuel cell bipolar plate, which improves the performance of the entire fuel cell stack, reduces the design difficulty, and shortens the development cycle; and as described in the abstract of the Chinese patent document with the publication number CN112467160A, the application discloses a fuel cell bipolar plate, including two metal monopolar plates welded in a mirror-symmetrical manner. Due to the symmetry of the structure, the formability and strength of the plate are increased to a certain extent.

[0004] For example, in the patent document with publication number CN107293767B, although the reaction gas water discharge and the coolant air bubble discharge are achieved, the symmetrical arrangement of the coolant inlet and outlet increases the thickness of the horizontal stack. In addition, in the patent document with publication number JP7059706B2, in order to maintain the symmetrical layout of the flow field inlet and outlet, an additional refrigerant flow path outside the power generation unit is set up, so that the mixed bubbles can be transferred to the refrigerant flow path outside the power generation unit located above the gravity direction. The structure is complex and still cannot completely solve the bubble discharge problem. For example, in the patent document with publication number CN115117413A, in order to maintain the symmetrical layout of the flow field inlet and outlet, a bypass flow path is set up to achieve the discharge of bubbles, but the bypass flow path makes the structure of the flow field layout of the fuel cell stack more complicated. Summary of the invention

[0005] The purpose of the embodiment of the present application is to provide a flow field inlet and outlet arrangement structure of a fuel cell, wherein a first channel portion and a second channel portion are respectively arranged opposite to each other at both ends of the reaction zone on the electrode plate, wherein the first channel portion is sequentially arranged with a cathode inlet, a coolant inlet and an anode outlet from top to bottom, and the second channel portion is sequentially arranged with a coolant outlet, an anode inlet and a cathode outlet from top to bottom, wherein the anode outlet and the cathode outlet are both arranged at the lower ends of both sides of the reaction zone along the width direction, which is conducive to discharging liquid water in the anode flow field and the cathode flow field; the coolant outlet is arranged at the upper end of one side of the reaction zone along the width direction, which is conducive to discharging tiny bubbles in the coolant flow field. The present invention greatly simplifies the fuel cell structure required for simultaneously realizing the upward exhaust of the coolant flow field outlet and the downward drainage of the gas flow field outlet through the asymmetric layout of the flow field inlets and outlets.

[0006] In a first aspect, the present application provides a flow field inlet and outlet arrangement structure of a fuel cell, comprising an electrode plate, a reaction zone, a first channel portion and a second channel portion arranged on the electrode plate at both ends of the reaction zone, and a transverse flow field located in the reaction zone and connecting the first channel portion and the second channel portion; wherein the first channel portion comprises a cathode inlet, a coolant inlet, and an anode outlet arranged in sequence from top to bottom; and the second channel portion comprises a coolant outlet, an anode inlet, and a cathode outlet arranged in sequence from top to bottom.

[0007] In one embodiment, the lateral flow field includes an anode flow field, a cathode flow field and a coolant flow field that are isolated from each other; wherein the anode flow field is used for the flow of a first gas, the cathode flow field is used for the flow of a second gas, and the coolant flow field is used for the flow of a coolant.

[0008] In one embodiment, the anode flow field is at least one flow channel arranged in parallel or in a serpentine shape; or, the anode flow field is a pore structure formed by a porous material; or, the anode flow field is a combination of at least one flow channel arranged in parallel or in a serpentine shape and a pore structure formed by a porous material; the cathode flow field is at least one flow channel arranged in parallel or in a serpentine shape; or, the cathode flow field is a pore structure formed by a porous material; or, the cathode flow field is a combination of at least one flow channel arranged in parallel or in a serpentine shape and a pore structure formed by a porous material; the coolant flow field is at least one flow channel arranged in parallel or in a serpentine shape; or, the coolant flow field is a pore structure formed by a porous material; or, the coolant flow field is a combination of at least one flow channel arranged in parallel or in a serpentine shape and a pore structure formed by a porous material.

[0009] In one embodiment, the flow resistance per unit length of the flow channel in the upper part of the anode flow field is lower than the flow resistance per unit length of the flow channel in the middle part of the anode flow field and / or the flow resistance per unit length of the flow channel in the lower part of the anode flow field;

[0010] Alternatively, the unit length flow resistance of the pore structure of the porous material in the upper part of the anode flow field is lower than the unit length flow resistance of the pore structure of the porous material in the middle part of the anode flow field and / or the unit length flow resistance of the pore structure of the porous material in the lower part of the anode flow field;

[0011] The flow resistance per unit length of the flow channel at the lower part of the coolant flow field is lower than the flow resistance per unit length of the flow channel at the middle part of the coolant flow field and / or the flow resistance per unit length of the flow channel at the upper part of the coolant flow field;

[0012] Alternatively, the unit length flow resistance of the pore structure of the porous material in the lower part of the coolant flow field is lower than the unit length flow resistance of the pore structure of the porous material in the middle part of the coolant flow field and / or the unit length flow resistance of the pore structure of the porous material in the upper part of the coolant flow field.

[0013] In one embodiment, the flow resistance per unit length of the flow channel in the middle of the cathode flow field is lower than the flow resistance per unit length of the flow channel in the upper part of the cathode flow field and / or the flow resistance per unit length of the flow channel in the lower part of the cathode flow field;

[0014] Alternatively, the unit length flow resistance of the pore structure of the porous material in the middle of the cathode flow field is lower than the unit length flow resistance of the pore structure of the porous material in the upper part of the cathode flow field and / or the unit length flow resistance of the pore structure of the porous material in the lower part of the cathode flow field.

[0015] In one embodiment, the cathode inlet, the coolant inlet, and the anode outlet are arranged on one short side of the reaction zone, and the coolant outlet, the anode inlet, and the cathode outlet are arranged on the other short side of the reaction zone.

[0016] In one embodiment, the first gas enters the reaction zone through the anode inlet and flows along the anode flow field toward the anode outlet.

[0017] In one embodiment, the second gas enters the reaction zone through the cathode inlet and flows along the cathode flow field toward the cathode outlet.

[0018] In one embodiment, the coolant enters the reaction zone through the coolant inlet and flows toward the coolant outlet along the coolant flow field.

[0019] In one embodiment, the area where the projection angle between the flow direction of the coolant in the coolant flow field and the flow direction of the second gas in the cathode flow field on the reaction zone plane is less than 90° accounts for no less than 50% of the area of ​​the reaction zone.

[0020] In a second aspect, the present application provides a fuel cell, comprising a flow field inlet and outlet arrangement structure of the fuel cell as described in any embodiment of the first aspect of the present application.

[0021] In a third aspect, the present application provides a fuel cell system, comprising the fuel cell as described in the embodiment of the second aspect of the present application.

[0022] In the technical solution of the present application, the first channel portion and the second channel portion are respectively arranged at the two ends of the reaction zone, and the anode outlet and the cathode outlet are both arranged at the lower ends of the two sides of the reaction zone along the width direction, which is conducive to discharging liquid water in the anode flow field and the cathode flow field; the coolant outlet is arranged at the upper end of one side of the reaction zone along the width direction, which is conducive to discharging tiny bubbles in the coolant flow field. The present invention greatly simplifies the fuel cell structure required to simultaneously realize the upward exhaust of the coolant flow field outlet and the downward drainage of the gas flow field outlet through the asymmetric layout of the flow field inlets and outlets. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the structure of the flow field inlet and outlet arrangement structure of a fuel cell provided in one embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of the anode flow field provided in one embodiment of the present application;

[0026] Figure 3 A schematic diagram of the structure of a cathode process provided in one embodiment of the present application;

[0027] Figure 4 A schematic diagram of the structure of a coolant flow field provided in one embodiment of the present application.

[0028] Reference numerals:

[0029] 1- flow field inlet and outlet arrangement structure of fuel cell; 10- plate; 11- first side; 12- second side; 13- third side; 14- fourth side; 20- reaction zone; 210- first channel portion; 211- cathode inlet; 212- coolant inlet; 213- anode outlet; 220- second channel portion; 221- coolant outlet; 222- anode inlet; 223- cathode outlet; 230- transverse flow field; 231- anode anode flow field; 232-cathode flow field; 233-coolant flow field; 301-flow channel at the top of anode flow field; 302-flow channel at the middle of anode flow field; 303-flow channel at the bottom of anode flow field; 401-flow channel at the top of cathode flow field; 402-flow channel at the middle of cathode flow field; 403-flow channel at the bottom of cathode flow field; 501-flow channel at the top of coolant flow field; 502-flow channel at the middle of coolant flow field; 503-flow channel at the bottom of coolant flow field. DETAILED DESCRIPTION

[0030] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and do not indicate the order of arrangement, nor can they be understood as indicating or implying relative importance.

[0031] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the present application, it should be noted that the terms "inside", "outside", "left", "right", "up", "down", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the products of the present application are usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0033] In the description of this application, unless otherwise clearly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0034] The technical solution of the present application will be described below in conjunction with the accompanying drawings.

[0035] An important component of a fuel cell is the plate. There are flow channels processed on both sides of the plate, which play an important role in distributing the reactant gas, collecting current, mechanical support, and dividing the positive and negative reactant gases. The flow field is a groove of various shapes processed on the plate, which provides an inlet and outlet for the reactants and products. The flow channel design of the plate has a great influence on the performance, operating efficiency and manufacturing cost of the fuel cell. Therefore, a reasonably designed plate and flow field can not only reduce the mass and thickness of the plate, improve the mass power and volume power of the fuel cell, but also evenly distribute the oxidant and reductant required by the battery, ensure the uniform distribution of current density, and smoothly discharge the water and tail gas generated by the battery.

[0036] Please refer to Figure 1 A flow field inlet and outlet arrangement structure 1 of a fuel cell comprises: an electrode plate 10, a reaction zone 20, a first channel portion 210 and a second channel portion 220 arranged on the electrode plate 10 at both ends of the reaction zone 20, and a transverse flow field 230 located in the reaction zone 20 and connecting the first channel portion 210 and the second channel portion 220; wherein the first channel portion 210 comprises a cathode inlet 211, a coolant inlet 212, and an anode outlet 213 arranged in sequence from top to bottom; the second channel portion 220 comprises a coolant outlet 221, an anode inlet 222, and a cathode outlet 223 arranged in sequence from top to bottom.

[0037] Regardless of whether the cathode gas or coolant enters the reaction zone 20 from the first channel portion 210 and then enters the second channel portion 220, or the anode gas enters the reaction zone 20 from the second channel portion 220 and then enters the first channel portion 210, the gas or coolant flows through the transverse flow field 230 and flows toward the first channel portion 210 or the second channel portion 220 under the uniform diffusion effect of the transverse flow field 230.

[0038] Further, the lateral flow field 230 includes an anode flow field 231, a cathode flow field 232, and a coolant flow field 233 that are isolated from each other. The anode flow field 231 and the coolant flow field 233 can be isolated by an anode plate, and the cathode flow field 232 and the coolant flow field 233 can be isolated by a cathode plate. The anode flow field 231 and the cathode flow field 232 are respectively used for the circulation of different gases, and the coolant flow field 233 is used for the circulation of the coolant. Exemplarily, the anode flow field 231 is used for the flow of the first gas, the cathode flow field 232 is used for the flow of the second gas, and the coolant flow field 233 is used for the flow of the coolant.

[0039] Furthermore, the anode flow field 231 is at least one flow channel arranged in parallel or serpentine shape; or, the anode flow field 231 is a pore structure formed by a porous material; or, the anode flow field 231 is a combination of at least one flow channel arranged in parallel or serpentine shape and a pore structure formed by a porous material.

[0040] The cathode flow field 232 is at least one flow channel arranged in parallel or serpentine shape; or, the cathode flow field 232 is a pore structure formed by a porous material; or, the cathode flow field 232 is a combination of at least one flow channel arranged in parallel or serpentine shape and a pore structure formed by a porous material.

[0041] The coolant flow field 233 is at least one flow channel arranged in parallel or serpentine shape; or, the coolant flow field 233 is a pore structure formed by a porous material; or, the coolant flow field 233 is a combination of at least one flow channel arranged in parallel or serpentine shape and a pore structure formed by a porous material.

[0042] In the above embodiment, the porous material may be foam material, glass fiber wool, etc. In the present application, the anode flow field 231, the cathode flow field 232, and the coolant flow field 233 may all be parallel flow channel structures.

[0043] Furthermore, the cathode inlet 211 , the coolant inlet 212 , and the anode outlet 213 are arranged on one short side of the reaction zone 20 , and the coolant outlet 221 , the anode inlet 222 , and the cathode outlet 223 are arranged on the other short side of the reaction zone 20 .

[0044] Optionally, one short side of the reaction zone 20 is the first side 11, and the other short side of the reaction zone 20 is the second side 12. The long sides connecting the first side 11 and the second side 12 are the third side 13 and the fourth side 14, respectively. The first channel portion 210 is arranged in the direction of the first side 11 of the electrode plate 10, and the second channel portion 220 is arranged in the direction of the second side 12 of the electrode plate 10. The first side 11 and the second side 12 are arranged opposite to each other, one end of the first side 11 and one end of the second side 12 are connected through the third side 13, the other end of the first side 11 and the other end of the second side 12 are connected through the fourth side 14, and the third side 13 and the fourth side 14 are arranged opposite to each other.

[0045] In this embodiment, the electrode plate 10 can be set to one of a rectangular shape and a square shape, wherein the first side 11 and the second side 12 are two side edges in the width direction of the electrode plate 10, respectively, and the third side 13 and the fourth side 14 are two side edges in the length direction of the electrode plate 10. When the electrode plate 10 is set to a rectangular structure, the first side 11 and the second side 12 are two short side edges in the width direction, and the third side 13 and the fourth side 14 are two long side edges in the length direction. The lengths of the first side 11 and the second side 12 are equal, the lengths of the third side 13 and the fourth side 14 are the same, and the lengths of the first side 11 and the second side 12 are both less than the lengths of the third side 13 and the fourth side 14.

[0046] Optionally, the setting directions of the anode flow field 231, the cathode flow field 232, and the coolant flow field 233 are all consistent with the extension direction of the third side 13 and / or the fourth side 14. When the electrode plate 10 is a rectangular structure, the direction of the lateral flow field 230 is consistent with the extension direction of the third side 13 and the fourth side 14. Alternatively, the direction of the lateral flow field 230 is consistent with the extension direction of one of the third side 13 or the fourth side 14.

[0047] Optional, see Figure 2 , the first gas enters the reaction zone 20 through the anode inlet 222, and flows along the anode flow field 231 to the anode outlet 213. In this embodiment, the first gas may be hydrogen, and the anode flow field 231 is used for the circulation of hydrogen gas. The hydrogen gas enters the anode flow field 231 in the reaction zone 20 through the anode inlet 222, flows through the parallel flow field channels in the anode flow field 231, and flows to the anode outlet 213.

[0048] For further information, please refer to Figure 2 , the flow resistance per unit length of the flow channel 301 in the upper part of the anode flow field is lower than the flow resistance per unit length of the flow channel 302 in the middle part of the anode flow field and / or the flow resistance per unit length of the flow channel 303 in the lower part of the anode flow field. Alternatively, the flow resistance per unit length of the pore structure of the porous material in the upper part of the anode flow field is lower than the flow resistance per unit length of the pore structure of the porous material in the middle part of the anode flow field and / or the flow resistance per unit length of the pore structure of the porous material in the lower part of the anode flow field.

[0049] In this embodiment, Figure 2 The flow channels arranged in parallel are shown as an example. In the prior art, since the flow field inlet and outlet layout adopts a symmetrical design, the flow distribution consistency of the gas or coolant in the flow field is easily achieved. However, in the present application, the arrangement order of the flow field inlets and outlets in the flow field inlet and outlet arrangement structure 1 of the fuel cell is not symmetrical, so when the flow channel structure parameters or the porous medium material parameters are not adjusted, the flow distribution of the anode gas or cathode gas or coolant in the flow field is not uniform.

[0050] from Figure 2It can be seen that the anode inlet 222 is arranged in the middle of the second side 12, and the anode outlet 213 is arranged at the lowest part of the first side 11; when the anode gas flows from the anode inlet 222 to the anode outlet 213, the distance that the anode gas flows through the flow channel 301 at the upper part of the anode flow field is the longest, that is, the distance that the anode gas flows through the flow channel 301 at the upper part of the anode flow field is longer than the distance that the anode gas flows through the flow channel 302 at the middle part of the anode flow field or the flow channel 303 at the lower part of the anode flow field. In order to overcome the unevenness of the flow field distribution of the anode gas in the flow channel 301 at the upper part of the anode flow field, the flow field distribution in the flow channel 302 at the middle part of the anode flow field, and the flow field distribution in the flow channel 303 at the lower part of the anode flow field, the flow channel size parameters in the flow channel 301 at the upper part of the anode flow field, the flow channel size parameters in the flow channel 302 at the middle part of the anode flow field, and the flow channel size parameters in the flow channel 303 at the lower part of the anode flow field can be adjusted. The result of the adjustment is that the flow resistance per unit length of the flow channel 301 in the upper part of the anode flow field is lower than the flow resistance per unit length of the flow channel 302 in the middle part of the anode flow field and the flow resistance per unit length of the flow channel 303 in the lower part of the anode flow field. Optionally, the adjusted flow channel size parameters include: the cross-sectional area of ​​the flow channel, the smoothness of the inner surface of the flow channel, etc.

[0051] In other optional embodiments, the parameters of the porous material at the top of the anode flow field, the parameters of the porous material at the middle of the anode flow field, and the parameters of the porous material at the bottom of the anode flow field can also be adjusted. The result of the adjustment is to make the unit length flow resistance of the pore structure of the porous material at the top of the anode flow field lower than any one of the unit length flow resistance of the pore structure of the porous material at the middle of the anode flow field and the unit length flow resistance of the pore structure of the porous material at the bottom of the anode flow field. Optionally, the parameters of the porous material to be adjusted include: porosity, porosity, specific surface area of ​​pores, etc. of the pore structure.

[0052] Optional, see Figure 3 , the second gas enters the reaction zone 20 through the cathode inlet 211, and flows toward the cathode outlet 223 along the direction of the cathode flow field 232. In this embodiment, the second gas may be air, and the cathode flow field 232 is used for the circulation of air. The air enters the cathode flow field 232 through the cathode inlet 211, flows through the parallel flow field channels in the cathode flow field 232, and flows toward the cathode outlet 223.

[0053] For further information, please refer to Figure 3, the unit length flow resistance of the flow channel 402 in the middle of the cathode flow field is lower than the unit length flow resistance of the flow channel 401 in the upper part of the cathode flow field and / or the unit length flow resistance of the flow channel 403 in the lower part of the cathode flow field. Alternatively, the unit length flow resistance of the pore structure of the porous material in the middle of the cathode flow field is lower than the unit length flow resistance of the pore structure of the porous material in the upper part of the cathode flow field and / or the unit length flow resistance of the pore structure of the porous material in the lower part of the cathode flow field.

[0054] from Figure 2 It can be seen that the cathode inlet 211 is arranged at the upper part of the first side 11, and the cathode outlet 223 is arranged at the lowest part of the second side 12; when the cathode gas flows from the cathode inlet 211 to the cathode outlet 223, the distance that the cathode gas flows through in the flow channel 402 in the middle of the cathode flow field is the longest, that is, the distance that the cathode gas flows through in the flow channel 402 in the middle of the cathode flow field is longer than the distance that the cathode gas flows through in the flow channel 401 in the upper part of the cathode flow field or the flow channel 403 in the lower part of the cathode flow field. In order to overcome the unevenness of the flow field distribution of the cathode gas in the flow channel 402 in the middle of the cathode flow field, the flow field distribution in the flow channel 401 in the upper part of the cathode flow field, and the flow field distribution in the flow channel 403 in the lower part of the cathode flow field, the flow channel size parameters in the flow channel 402 in the middle of the cathode flow field, the flow channel size parameters in the flow channel 401 in the upper part of the cathode flow field, and the flow channel size parameters in the flow channel 403 in the lower part of the cathode flow field can be adjusted. The result of the adjustment is that the flow resistance per unit length of the flow channel 402 in the middle of the cathode flow field is lower than the flow resistance per unit length of the flow channel 401 in the upper part of the cathode flow field and the flow resistance per unit length of the flow channel 403 in the lower part of the cathode flow field. Optionally, the adjusted flow channel size parameters include: the cross-sectional area of ​​the flow channel, the smoothness of the inner surface of the flow channel, etc.

[0055] In other optional embodiments, as described above, the parameters of the porous material in the middle of the cathode flow field, the parameters of the porous material in the upper part of the cathode flow field, and the parameters of the porous material in the lower part of the cathode flow field can also be adjusted. The result of the adjustment is to make the unit length flow resistance of the pore structure of the porous material in the middle of the cathode flow field lower than any one of the unit length flow resistance of the pore structure of the porous material in the upper part of the cathode flow field and the unit length flow resistance of the pore structure of the porous material in the lower part of the cathode flow field. Optionally, the parameters of the porous material to be adjusted include: porosity, porosity, specific surface area of ​​pores, etc. of the pore structure.

[0056] Optional, see Figure 4 The coolant enters the reaction zone 20 through the coolant inlet 212, and flows toward the coolant outlet 221 along the coolant flow field 233. In this embodiment, the coolant enters the coolant flow field 233 through the coolant inlet 212, flows through the parallel flow field channels in the coolant flow field 233, and flows toward the coolant outlet 221.

[0057] For further information, please refer to Figure 4 , the unit length flow resistance of the flow channel 503 at the lower part of the coolant flow field is lower than the unit length flow resistance of the flow channel 501 at the upper part of the coolant flow field and / or the unit length flow resistance of the flow channel 502 at the middle part of the coolant flow field. Alternatively, the unit length flow resistance of the pore structure of the porous material at the lower part of the coolant flow field is lower than the unit length flow resistance of the pore structure of the porous material at the upper part of the coolant flow field and / or the unit length flow resistance of the pore structure of the porous material at the middle part of the coolant flow field.

[0058] from Figure 2 It can be seen that the coolant inlet 212 is arranged in the middle of the first side 11, and the coolant outlet 221 is arranged at the uppermost part of the second side 12; when the coolant flows from the coolant inlet 212 to the coolant outlet 221, the distance the coolant flows through the flow channel 503 in the lower part of the coolant flow field is the longest, that is, the distance the coolant flows through the flow channel 503 in the lower part of the coolant flow field is longer than any of the distances the coolant flows through the flow channel 502 in the middle part of the coolant flow field or the distances the coolant flows through the flow channel 501 in the upper part of the coolant flow field. In order to overcome the unevenness of the flow field distribution of the coolant in the flow channel 501 at the upper part of the coolant flow field, the flow field distribution in the flow channel 502 in the middle part of the coolant flow field, and the flow field distribution in the flow channel 503 at the lower part of the coolant flow field, the flow channel size parameters in the flow channel 503 at the lower part of the coolant flow field, the flow channel size parameters in the flow channel 502 in the middle part of the coolant flow field, and the flow channel size parameters in the flow channel 501 at the upper part of the coolant flow field. The result of the adjustment is to make the unit length flow resistance of the flow channel 503 at the lower part of the coolant flow field lower than any one of the unit length flow resistance of the flow channel 502 in the middle part of the coolant flow field and the unit length flow resistance of the flow channel 501 at the upper part of the coolant flow field. Optionally, the adjusted flow channel size parameters include: the cross-sectional area of ​​the flow channel, the smoothness of the inner surface of the flow channel, etc.

[0059] In other optional embodiments, as described above, the parameters of the porous material at the bottom of the coolant flow field, the parameters of the porous material at the middle of the coolant flow field, and the parameters of the porous material at the top of the coolant flow field can also be adjusted. The result of the adjustment is to make the unit length flow resistance of the pore structure of the porous material at the bottom of the coolant flow field lower than the unit length flow resistance of the pore structure of the porous material at the middle of the coolant flow field and the unit length flow resistance of the porous material at the top of the coolant flow field. Optionally, the parameters of the porous material to be adjusted include: porosity, porosity, specific surface area of ​​pores, etc. of the pore structure.

[0060] For further information, please refer to Figure 3 and Figure 4The area of ​​the region where the projection angle between the flow direction of the coolant in the coolant flow field 233 and the flow direction of the second gas in the cathode flow field 232 on the plane of the reaction zone 20 is less than 90° accounts for no less than 50% of the area of ​​the reaction zone 20.

[0061] In this embodiment, when the coolant flows through the parallel flow channels on the coolant flow field 233, the direction of the coolant flow includes three components. One is to continue to the right after passing through the parallel flow channels ( Figure 4 As shown in FIG. 2 , one is an upward component that climbs upward in the parallel flow channel and contacts the electrode plate 10, and the other is a lateral component that flows downward in the parallel flow channel. Similarly, the flow state of the second gas flowing through the flow channel in the cathode flow field 232 is the same as the state of the coolant passing through the coolant flow field 233.

[0062] When the projection angle between the flow direction of the coolant in the coolant flow field 233 and the flow direction of the second gas in the cathode flow field 232 on the plane of the reaction zone 20 is less than 90°, it means that the flow direction of the coolant in the coolant flow field 233 is consistent with the overall flow direction of the second gas in the cathode flow field 232.

[0063] The area where the projection angle is less than 90° accounts for no less than 50% of the area of ​​the reaction zone 20, further indicating that the flow direction of the coolant in the coolant flow field 233 is roughly consistent with the overall flow direction of the second gas in the cathode flow field 232, but it is impossible to ensure that the flow directions of the liquid and gas in all places in the reaction zone 20 are consistent.

[0064] The flow direction of the coolant in the coolant flow field 233 is consistent with the flow direction of the second gas in the cathode flow field 232. That is, the coolant in the coolant flow field 233 and the air in the cathode flow field 232 flow in the same direction.

[0065] As mentioned above, the first channel portion 210 and the second channel portion 220 are respectively arranged at the two ends of the reaction zone 20, and the anode outlet 213 is arranged at the lower end of the second side 12, which is conducive to discharging liquid water in the anode flow field 231. In addition, the design layout of the anode flow field 231 and the cathode flow field 232 ensures that the gas can evenly enter the positive and negative electrodes of the fuel cell stack.

[0066] In order to reduce the problem of uniform distribution of the coolant, the coolant inlet 212 is not suitable to be arranged at the upper end of the first side 11. Therefore, in this embodiment, the coolant inlet 212 is arranged at the middle end of the first side 11, and the coolant outlet 221 is arranged at the upper end of the second side 12.

[0067] Since the oxygen concentration in the air entering the cathode inlet 211 during the initial operation of the fuel cell is high and the diffusion is poor, it is easy to cause large local thermal stress at the cathode inlet 211. Therefore, the coolant inlet 212 is arranged between the cathode inlet 211 and the anode outlet 213, and the coolant outlet 221 is arranged at the upper end of the second side 12. The coolant flow field 233 ensures that the coolant is evenly distributed and the heat dissipation effect inside the electrode plate 10 is evenly distributed.

[0068] In the present application, the anode outlet 213, the cathode inlet 211 and the coolant inlet 212 are only arranged on the first side 11 in the width direction of the electrode plate 10, and from top to bottom they are the cathode inlet 211, the coolant inlet 212 and the anode outlet 213; on the second side 12 opposite to the first side 11 in the width direction of the electrode plate 10, the coolant outlet 221, the anode inlet 222 and the cathode outlet 223 are arranged in sequence from top to bottom.

[0069] In the present application, the arrangement order of the flow field inlet and outlet in the first channel portion 210 is asymmetric to the arrangement order of the flow field inlet and outlet in the second channel portion 220, which can realize the design structure of the flow field inlet and outlet of "the exhaust port of the coolant flow field is facing upward, and the drainage of the gas flow field is facing downward" to discharge the liquid water of the cathode flow field 232 and the anode flow field 231, and the bubble problem of the coolant flow field 233, and can also not increase the thickness and structural complexity of the horizontal stack. Thus, through the asymmetric layout of the inlet and outlet of each flow field, the fuel cell structure required to simultaneously realize the exhaust of the coolant flow field 233 upward and the drainage of the gas flow field (i.e., the anode flow field 231 and the cathode flow field 232) outlet downward is simplified.

[0070] The present application provides a fuel cell, comprising Figure 1-Figure 4 The flow field inlet and outlet arrangement structure 1 of the fuel cell is shown. Optionally, the fuel cell includes a bipolar plate composed of a cathode plate and an anode plate and a membrane electrode connecting adjacent bipolar plates. When packaging, the membrane electrodes are alternately stacked on the outside of the bipolar plate to form a fuel cell structure of a membrane electrode-bipolar plate. The fuel cell can also be a fuel cell monomer, which is composed of a cathode plate-membrane electrode-anode plate. When packaging, the membrane electrode is repeatedly stacked on the inside of the bipolar plate, a cathode flow field 232 is formed between the cathode plate and the membrane electrode, an anode flow field 231 is formed between the anode plate and the membrane electrode, and a complete coolant flow field 233 is formed between adjacent fuel cell monomers.

[0071] The present application also provides a fuel cell system, including the above-mentioned fuel cell. Optionally, the fuel cell system can be applied to a vehicle. In addition, the fuel cell system can also be applied to structures including a stacking machine, a hot press, an assembly machine, etc.

[0072] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0073] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A flow field inlet and outlet arrangement structure of a fuel cell, characterized in that: include An electrode plate, a reaction zone, a first channel portion and a second channel portion disposed on the electrode plate at both ends of the reaction zone, and a transverse flow field located in the reaction zone and connecting the first channel portion and the second channel portion; Wherein, the first channel portion includes a cathode inlet, a coolant inlet, and an anode outlet arranged in sequence from top to bottom; the second channel portion includes a coolant outlet, an anode inlet, and a cathode outlet arranged in sequence from top to bottom; The lateral flow field includes an anode flow field, a cathode flow field and a coolant flow field which are isolated from each other; Wherein, the anode flow field is used for the flow of the first gas, the cathode flow field is used for the flow of the second gas, and the coolant flow field is used for the flow of the coolant; The anode flow field is at least one flow channel arranged in parallel or serpentine, or the anode flow field is a pore structure formed by a porous material, or the anode flow field is a combination of at least one flow channel arranged in parallel or serpentine and a pore structure formed by a porous material; The cathode flow field is at least one flow channel arranged in parallel or serpentine, or the cathode flow field is a pore structure formed by a porous material, or the cathode flow field is a combination of at least one flow channel arranged in parallel or serpentine and a pore structure formed by a porous material; The coolant flow field is at least one flow channel arranged in parallel or serpentine, or the coolant flow field is a pore structure formed by a porous material, or the coolant flow field is a combination of at least one flow channel arranged in parallel or serpentine and a pore structure formed by a porous material; Wherein, the flow resistance per unit length of the flow channel in the upper part of the anode flow field is lower than the flow resistance per unit length of the flow channel in the middle part of the anode flow field and / or the flow resistance per unit length of the flow channel in the lower part of the anode flow field, or, the flow resistance per unit length of the pore structure of the porous material in the upper part of the anode flow field is lower than the flow resistance per unit length of the pore structure of the porous material in the middle part of the anode flow field and / or the flow resistance per unit length of the pore structure of the porous material in the lower part of the anode flow field; The unit length flow resistance of the flow channel at the lower part of the coolant flow field is lower than the unit length flow resistance of the flow channel at the middle part of the coolant flow field and / or the unit length flow resistance of the flow channel at the upper part of the coolant flow field, or the unit length flow resistance of the pore structure of the porous material at the lower part of the coolant flow field is lower than the unit length flow resistance of the pore structure of the porous material at the middle part of the coolant flow field and / or the unit length flow resistance of the pore structure of the porous material at the upper part of the coolant flow field; Among them, the unit length flow resistance of the flow channel in the middle part of the cathode flow field is lower than the unit length flow resistance of the flow channel in the upper part of the cathode flow field and / or the unit length flow resistance of the flow channel in the lower part of the cathode flow field, or the unit length flow resistance of the pore structure of the porous material in the middle part of the cathode flow field is lower than the unit length flow resistance of the pore structure of the porous material in the upper part of the cathode flow field and / or the unit length flow resistance of the pore structure of the porous material in the lower part of the cathode flow field.

2. The flow field inlet and outlet arrangement structure of the fuel cell according to claim 1, characterized in that: The cathode inlet, the coolant inlet, and the anode outlet are arranged on one short side of the reaction zone, and the coolant outlet, the anode inlet, and the cathode outlet are arranged on the other short side of the reaction zone.

3. The flow field inlet and outlet arrangement structure of the fuel cell according to claim 1, characterized in that: The first gas enters the reaction zone through the anode inlet and flows along the anode flow field to the anode outlet.

4. The flow field inlet and outlet arrangement structure of the fuel cell according to claim 1, characterized in that: The second gas enters the reaction zone through the cathode inlet and flows toward the cathode outlet along the cathode flow field.

5. The flow field inlet and outlet arrangement structure of the fuel cell according to claim 1, characterized in that: The coolant enters the reaction zone through the coolant inlet and flows toward the coolant outlet along the coolant flow field.

6. The flow field inlet and outlet arrangement structure of the fuel cell according to claim 4 or 5, characterized in that: The area of ​​the region where the projection angle between the flow direction of the coolant in the coolant flow field and the flow direction of the second gas in the cathode flow field on the plane of the reaction zone is less than 90° accounts for no less than 50% of the area of ​​the reaction zone.

7. A fuel cell, characterized in that: A flow field inlet and outlet arrangement structure of a fuel cell comprising the structure described in any one of claims 1 to 6.

8. A fuel cell system, characterized in that: Comprising the fuel cell as claimed in claim 7.

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