Bipolar plate with streamline structure

Abstract

The utility model relates to the technical field of bipolar plates, in particular to a bipolar plate with a streamline structure, which comprises a plate body, and an inlet manifold area, an inlet distribution area, an active reaction area, an outlet distribution area and an outlet manifold area which are sequentially connected are arranged on the plate body. Dot matrix units for guiding fluid are arranged on the inlet distribution area and the outlet distribution area respectively; the lattice unit comprises an air flow field lattice structure matched with an air field for use, a hydrogen flow field lattice structure matched with a hydrogen field and a cooling liquid flow field lattice structure matched with a cooling liquid flow field for use, and the active reaction area is provided with parallel flow channels or S-shaped flow channels. The reactor disclosed by the utility model can effectively solve the problems of large flow resistance, non-uniform fluid distribution in a reaction area and large contact resistance.

Description

Technical Field

[0001] The utility model relates to the technical field of bipolar plates, and more specifically to a bipolar plate with a streamlined structure. Background Art

[0002] The main function of the bipolar plate in a proton exchange membrane fuel cell is to conduct current and provide reactants and coolant. The fluids in a proton exchange membrane fuel cell include hydrogen, air and coolant. The bipolar plate flow field structure needs to be designed to make the fluid distribution in the reaction zone uniform. If the hydrogen and air are unevenly distributed, it will affect the local electrochemical reaction activity, resulting in uneven current and voltage of the battery cell, uneven heat generation and additional energy loss. If the coolant is unevenly distributed, it will cause uneven temperature distribution inside the single cell, causing greater local thermal stress, affecting the output performance and service life of the battery stack.

[0003] With the increase of the power density and current density of the stack, the requirements for the thickness of the bipolar plate and the flow field design of the bipolar plate will become higher and higher. After a large amount of reactant gas flows through the air and hydrogen flow fields of the bipolar plate with a small flow area, the pressure drop of the air path and the hydrogen path is very different, resulting in a large pressure difference between the anode and cathode of the proton exchange membrane. The excessive pressure difference directly affects the service life of the proton membrane and then the service life of the stack. High-power fuel cells usually use liquid cooling. The coolant in the cooling plate can take away the excess heat generated by the electrochemical reaction. The design of the cooling flow channel has a great influence on the heat dissipation of the fuel cell stack. A good design can make the temperature distribution in the stack more uniform and the pressure drop of the cooling circuit smaller. At the same coolant flow rate, the water pump power consumption is smaller, reducing the output power of the water pump and improving the efficiency of the fuel cell system.

[0004] Announcement No. CN215418242U discloses a proton exchange membrane fuel cell bipolar plate flow field structure, which adopts a staggered lattice structure flow field to achieve uniform distribution of hydrogen, air, and coolant flow velocities. The staggered lattice includes circular lattice, rectangular lattice, and irregular lattice. The irregular lattice adopts a streamlined design;

[0005] The bipolar plate structure provided by the patent has a dot matrix set in the entire flow field area, and the anode and cathode graphite plates are difficult to match well, which will result in excessive contact resistance between the membrane electrode and the bipolar plate. At the same time, when a streamlined structure is adopted, the fluid flow direction is from the trailing edge to the leading edge of the streamlined structure, which will cause more eddy currents at the tail of the streamlined structure and greater flow resistance. At the same time, the patent does not provide detailed descriptions of the type parameters, layout methods and other designs of the streamlined structure.

[0006] Announcement No. CN210200872U involves a teardrop-shaped proton exchange membrane fuel cell stack cooling channel, including a cooling plate, on which an inlet channel, a teardrop-shaped cooling channel and an outlet channel are arranged; the teardrop-shaped cooling channel is arranged forward or reversely, staggered or parallel in the cooling plate, and the inlet channel and the outlet channel are symmetrically arranged at the upper and lower parts of the cooling plate.

[0007] The structure of the cooling channel in this patent is teardrop-shaped, but the direction of fluid flow is from the trailing edge to the leading edge of the teardrop-shaped structure. This arrangement will cause more vortices to be generated at the tail of the teardrop-shaped structure, resulting in greater energy loss.

[0008] Publication No. CN114464835A provides a teardrop-shaped bipolar plate and its use, wherein the parallel flow channels in the flow field inlet area of ​​the teardrop-shaped bipolar plate are distributed decreasingly to ensure that the gas can enter the flow field as evenly as possible when entering from the inlet; the teardrop-shaped structure can reduce the flow resistance of the fluid and is beneficial to the uniformity of gas distribution; the teardrop-shaped rib structure is staggered along the gas flow direction to increase the turbulence of the gas and ensure the uniformity of temperature distribution.

[0009] The structure of the flow channel in the active reaction zone in this patent is in the shape of a teardrop. It is difficult for the anode and cathode graphite plates to be well aligned and matched, which will result in excessive contact resistance between the membrane electrode and the bipolar plate. At the same time, the fluid flows from the trailing edge to the leading edge. This arrangement will cause more eddies to form at the tail of the teardrop-shaped structure, resulting in greater energy loss.

[0010] Announcement No. CN113611890B discloses a streamlined diversion structure and method for a flow-guiding channel, which adopts a streamlined design of a diversion island, and by changing the curvature radius of the streamline of the diversion island, a vortex is formed in the fluid channel to prevent the generated water from sticking to the side wall of the fluid channel, and by changing the fluid flow rate and pressure at each position in the fluid channel, the reaction medium is more effectively transferred and the generated water can be more effectively discharged. In this patent, the generation of more vortices will inevitably increase the flow resistance.

[0011] Publication No. CN115347212A discloses a bionic peregrine falcon flow channel structure of a proton exchange membrane fuel cell, the upper surface of which is a periodic structure composed of a number of asymmetric waveform units with streamlined shapes of the abdomen of a bionic peregrine falcon, and the lower surface is horizontal.

[0012] This patent has a streamlined asymmetric waveform unit on the bionic peregrine falcon's abdomen located at the bottom of the parallel flow channels in the reaction zone, so the flow resistance is actually greater than that of the traditional parallel straight flow channel design.

[0013] Publication No. CN111540923A discloses a cathode plate with protrusions and depressions. The cathode plate is a rectangular metal plate, and a flow field structure formed by a plurality of protrusions and a plurality of depressions is formed in the middle of the cathode plate; the protrusions are semi-water drop-shaped protrusions, and the depressions are the same semi-water drop-shaped depressions; along the X direction, the protrusions and depressions are alternately arranged, and the semi-water drop-shaped protrusions and the semi-water drop-shaped depressions are in opposite directions, that is, the direction in which the tail of the semi-water drop-shaped depression points to the head is in the opposite direction of X.

[0014] In this patent, the alternating arrangement of protrusions and depressions causes greater dissipation of fluid motion. At the same time, the flow field structure is a three-dimensional flow field, and its processing process is complicated.

[0015] Announcement No. CN213483784U discloses a cathode plate flow channel structure for a hydrogen fuel cell, including a cathode plate assembly, wherein a plurality of protrusions are evenly distributed on the surface of the cathode plate assembly, wherein the cross-sectional shape of the protrusion in top view is a wing cross-section, and its outer contour is divided into an upper arc edge, a lower arc edge, a leading edge, a trailing edge, and the like. The utility model provides an airfoil protrusion so that when the cathode gas flow passes through a single protrusion, a gas velocity difference is generated on both sides of the airfoil protrusion, and a certain pressure difference is generated at the same time, thereby promoting the diffusion of gas from the high pressure area to the low pressure area through the gas diffusion layer. The two sides of the airfoil protrusion are designed to be streamlined similar to the cross-section of the wing, which is more conducive to blowing away the accumulated water on both sides of the protrusion. At the same time, the protrusion is slender, and the tail is thinner, which can effectively avoid the vortex generated by the wake of a general circular or square protrusion, and is conducive to blowing away the accumulated water.

[0016] Because the lattice is set in the active reaction area, the anode and cathode graphite plates are difficult to align and match well, which will lead to excessive contact resistance between the membrane electrode and the bipolar plate. Utility Model Content

[0017] The technical problem to be solved by the utility model is to provide a bipolar plate with a streamlined structure, which can effectively solve the problems of large flow resistance, uneven fluid distribution in the reaction zone and large contact resistance;

[0018] The solution adopted by the utility model to solve the technical problem is:

[0019] A bipolar plate with a streamlined structure comprises a plate body, on which an inlet manifold area, an inlet distribution area, an active reaction area, an outlet distribution area and an outlet manifold area are arranged in sequence;

[0020] The inlet distribution area and the outlet distribution area are respectively provided with lattice units for guiding the fluid;

[0021] The lattice unit includes an air flow field lattice structure used in conjunction with an air field, a hydrogen flow field lattice structure used in conjunction with a hydrogen field, and a coolant flow field lattice structure used in conjunction with a coolant flow field.

[0022] In some possible implementations,

[0023] The air flow field lattice structure, the hydrogen flow field lattice structure and the coolant flow field lattice structure all include a plurality of rows of streamlined structural units arranged in a staggered manner; a fluid channel is formed between two adjacent rows of streamlined structural units.

[0024] In some possible implementations,

[0025] The inlet manifold area includes an inlet air manifold area, an inlet hydrogen manifold area, and an inlet coolant manifold area;

[0026] The inlet distribution area includes an air inlet distribution area, a hydrogen inlet distribution area, and a coolant inlet distribution area;

[0027] The active reaction zone includes an air flow field active reaction zone, a hydrogen flow field active reaction zone, and a coolant main flow channel zone;

[0028] The outlet distribution area includes an air outlet distribution area, a hydrogen outlet distribution area, and a coolant outlet distribution area;

[0029] The outlet manifold area includes an outlet air manifold area, an outlet hydrogen manifold area, and an outlet coolant manifold area.

[0030] The inlet air manifold area, the air inlet distribution area, the air active reaction area, the air outlet distribution area, and the outlet air manifold area are connected in sequence;

[0031] The inlet hydrogen manifold area, the hydrogen inlet distribution area, the hydrogen flow field active reaction area, the hydrogen outlet distribution area, and the outlet hydrogen manifold area are connected in sequence;

[0032] The inlet coolant manifold area, the coolant inlet distribution area, the coolant main channel area, and the coolant outlet distribution area are connected in sequence.

[0033] In some possible implementations,

[0034] The streamlined structural units in each column include a plurality of groups of streamlined columnar unit structures arranged after CFD calculation; the streamlined columnar unit structures in two adjacent groups of streamlined structural units are arranged in a staggered manner.

[0035] In some possible implementations,

[0036] The front edge of the streamlined columnar unit structure has an arc-shaped cross section with a curvature radius of R, an angle between the upper and lower curves at the rear edge is a rear edge angle, a straight line connecting the front edge and the rear edge is a chord line, and the length of the chord line is c;

[0037] The maximum thickness of the streamlined columnar unit structure is t; the maximum thickness is the maximum distance between the upper curve and the lower curve when the line connecting the upper curve and the lower curve is perpendicular to the chord line;

[0038] Among them, the distance between the section with the maximum distance and the leading edge is Xt;

[0039] The maximum distance between the median arc line and the chord line in each set of streamlined columnar unit structures is the maximum curvature, and the maximum curvature is f;

[0040] Among them, the distance between the section where the maximum curvature is located and the leading edge is Xf;

[0041] The middle arc line is a line connecting the centers of multiple groups of inscribed circles that are inscribed in the upper curve and the lower curve respectively.

[0042] In some possible implementations,

[0043] c=0.2-10mm, t=0.1-10mm, R=0.1-5mm, f=0-5mm.

[0044] In some possible implementations,

[0045] The trailing edge angle is an acute angle or an arc shape;

[0046] When the trailing edge angle is in an arc shape, the radius of curvature is r, r=0.02-5 mm, wherein R≥r.

[0047] In some possible implementations,

[0048] The angle between the fluid flow direction and the chord line is θ, where 0°≤θ≤90°.

[0049] In some possible implementations,

[0050] The distance between two adjacent columns of the streamlined structural units is h, and the distance between two adjacent groups of streamlined columnar unit structures in each column of streamlined structural units is s; wherein, 100mm>h>0.2mm, 50mm>s>0.2mm.

[0051] In some possible implementations,

[0052] The active reaction zone is provided with parallel flow channels or S-shaped flow channels.

[0053] Compared with the prior art, the utility model has the following beneficial effects:

[0054] The utility model provides a streamlined columnar unit structure, so that the fluid can enter the active reaction zone as evenly as possible. The streamlined columnar unit structure can reduce the flow resistance of the fluid, ensure a small pressure difference between the anode and cathode of the membrane electrode and uniform temperature distribution in the battery, and reduce the power consumption of the water pump, thereby improving the safety performance and overall output performance of the fuel cell, and ensuring the long-term safe, stable and efficient operation of the fuel cell.

[0055] The utility model sets parallel flow channels or S-shaped flow channels in the active reaction zone, which can effectively ensure good contact between the anode and cathode plates and the membrane electrode, and also ensure effective pressure drop in the active reaction zone, which is beneficial to the uniformity of fluid flow, flow resistance and temperature distribution in the active reaction zone and the discharge of reaction generated water;

[0056] The utility model uses a lattice structure in conjunction with parallel flow channels in the active reaction zone, so that the pressure drop in the active reaction zone can be adjusted over a larger range, ensuring an effective pressure drop in the active reaction zone, and can effectively improve the fluid flow, flow resistance, temperature distribution and flow channel drainage in the active reaction zone; at the same time, it improves the overall output performance and safety performance of the fuel cell, ensuring long-term stable and efficient operation of the fuel cell, and solving the problems of low output performance of the fuel cell, large fluid flow resistance, large contact resistance and uneven fluid distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic diagram of the partition in the utility model;

[0058] Figure 2 It is a structural schematic diagram of the streamlined columnar unit structure in the utility model;

[0059] Figure 3 It is a structural schematic diagram of a streamlined columnar unit structure with an acute rear edge in the utility model;

[0060] Figure 4 It is a structural schematic diagram of a streamlined columnar unit structure with an arc-shaped rear edge in the utility model;

[0061] Figure 5 It is a structural schematic diagram of the fluid flow direction and the streamlined columnar unit structure in the utility model;

[0062] Figure 6 It is a schematic diagram of the arrangement of the streamlined columnar unit structure on the plate body in the utility model;

[0063] Figure 7 A schematic diagram of the arrangement of the hydrogen flow field lattice structure in the utility model;

[0064] Figure 8 A schematic diagram of the arrangement of the coolant flow field lattice structure in the utility model;

[0065] Fig. 9 This is a comparison diagram of the pressure drop in the air flow field of the utility model and the non-streamlined structure at different current densities;

[0066] Wherein: 1. plate body; 11. air inlet distribution area; 12. air active reaction area; 13. air outlet distribution area; 14. hydrogen inlet distribution area; 15. hydrogen active reaction area; 16. hydrogen outlet distribution area; 17. coolant inlet distribution area; 18. coolant main channel area; 19. coolant outlet distribution area; 100. inlet air manifold area; 101. inlet hydrogen manifold area; 102. inlet coolant manifold area; 103. outlet air manifold area; 104. outlet hydrogen manifold area; 105. outlet coolant manifold area; 2. streamlined columnar unit structure; 21. leading edge; 22. trailing edge; 23. upper curve; 24. lower curve; 25. chord line; 26. middle arc line. DETAILED DESCRIPTION

[0067] In the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity limit, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can indicate: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0068] The utility model is described in detail below.

[0069] like Figure 1-Figure 8 As shown;

[0070] A bipolar plate with a streamlined structure comprises a plate body 1, on which an inlet manifold area, an inlet distribution area, an active reaction area, an outlet distribution area and an outlet manifold area are arranged in sequence;

[0071] The inlet distribution area and the outlet distribution area are respectively provided with lattice units for guiding the fluid;

[0072] The lattice unit includes an air flow field lattice structure used in conjunction with the air field, a hydrogen flow field lattice structure used in conjunction with the hydrogen field, and a coolant flow field lattice structure used in conjunction with the coolant flow field;

[0073] The air flow field lattice structure, the hydrogen flow field lattice structure, and the coolant flow field lattice structure do not interfere with each other to form three groups of conveying channels for corresponding fluids to pass through;

[0074] The active reaction zone is provided with parallel flow channels or S-shaped flow channels.

[0075] Air passes through the air flow field lattice structure, hydrogen passes through the hydrogen flow field lattice structure, and coolant passes through the coolant flow field lattice structure to enter the corresponding active reaction zone. By setting parallel flow channels or S-shaped flow channels in the active reaction zone, good contact between the anode and cathode plates and the membrane electrode can be ensured, and at the same time, effective pressure drop in the active reaction zone can be ensured, which is beneficial to the uniform distribution of fluid flow, flow resistance and temperature in the active reaction zone, and discharge of water generated after the reaction;

[0076] In some possible implementations, the flow resistance of the fluid is effectively reduced, ensuring a small pressure difference between the cathode and anode of the membrane electrode and uniform temperature distribution in the battery;

[0077] The air flow field lattice structure, the hydrogen flow field lattice structure, and the coolant flow field lattice structure all include multiple rows of streamlined structural units arranged in a staggered manner; a fluid channel is formed between two adjacent rows of streamlined structural units; the arrangement of the streamlined structural units in the air flow field lattice structure, the hydrogen flow field lattice structure, and the coolant flow field lattice structure can be different or the same;

[0078] In some possible embodiments, in order to allow air, hydrogen and coolant to enter the active reaction zone;

[0079] The active reaction zone includes an air active reaction zone 12, a hydrogen flow field active reaction zone 15, and a coolant main flow channel zone 18;

[0080] The inlet manifold area includes an inlet air manifold area 100, an inlet hydrogen manifold area 101, and an inlet coolant manifold area 102 which are respectively connected to the inlet distribution area;

[0081] The inlet distribution area includes an air inlet distribution area 11, a hydrogen inlet distribution area 14, and a coolant inlet distribution area 17;

[0082] The outlet manifold area includes an outlet air manifold area 103, an outlet hydrogen manifold area 104, and an outlet coolant manifold area 105 which are respectively connected to the outlet distribution area.

[0083] The outlet distribution area includes an air outlet distribution area 13, a hydrogen outlet distribution area 16, and a coolant outlet distribution area 19;

[0084] like Figure 1 As shown, the inlet air manifold area 100 is connected to the air flow field lattice structure of the air inlet distribution area 11, and the air is transported to the air active reaction area 12 through the air flow field lattice structure; the reacted air is discharged from the air flow field lattice structure set in the outlet distribution area 13 to the outlet air manifold area 103;

[0085] like Figure 7 As shown, the inlet hydrogen manifold area 101 is connected to the hydrogen flow field lattice structure of the hydrogen inlet distribution area 14, and the hydrogen is transported to the hydrogen active reaction area 15 through the hydrogen flow field lattice structure; the reacted hydrogen is discharged from the hydrogen flow field lattice structure set in the hydrogen outlet distribution area 16 to the outlet hydrogen manifold area 104;

[0086] like Figure 8 As shown, the inlet coolant manifold area 102 is connected to the coolant flow field lattice structure of the coolant inlet distribution area 17, and the coolant is transported to the coolant main channel area 18 through the coolant flow field lattice structure to cool the reaction areas (air active reaction area 12 and hydrogen flow field active reaction area 15); the cooled coolant is discharged from the coolant flow field lattice structure set in the coolant outlet distribution area 19 to the outlet coolant manifold area 105.

[0087] In some possible implementations,

[0088] The streamlined structural units in each column include a plurality of groups of streamlined columnar unit structures 2 arranged after CFD calculation; the streamlined columnar unit structures 2 in two adjacent groups of streamlined structural units are arranged in a staggered manner.

[0089] In some possible implementations,

[0090] The cross section of each group of the streamlined columnar unit structures 2 is in the shape of a water drop, and includes a leading edge 21 and a trailing edge 22 arranged on a side close to the direction of the fluid flow, and an upper curve 23 and a lower curve 24 for connecting the leading edge 21 and the trailing edge 22;

[0091] The front edge of the streamlined columnar unit structure has an arc-shaped cross section with a curvature radius of R, an angle between the upper curve 23 and the lower curve 24 at the rear edge 22 is a rear edge angle, a straight line connecting the front edge 21 and the rear edge 22 is a chord line 25, and a length of the chord line 25 is c;

[0092] The maximum thickness of the streamlined columnar unit structure 2 is t; the maximum thickness is the maximum distance between the upper curve 23 and the lower curve 24 when the line connecting the upper curve 23 and the lower curve 24 is perpendicular to the chord line;

[0093] Among them, the distance between the section with the maximum distance and the leading edge 21 is Xt;

[0094] The maximum distance between the arc line 26 and the chord line 25 in each group of streamlined columnar unit structures 2 is the maximum curvature f;

[0095] Wherein, the distance between the section where the maximum curvature is located and the leading edge 21 is Xf;

[0096] The middle arc line 26 is a line connecting the centers of multiple groups of inscribed circles that are inscribed in the upper curve 23 and the lower curve 24 respectively;

[0097] Further, c = 0.2-10 mm, t = 0.1-10 mm, R = 0.1-5 mm, f = 0-5 mm.

[0098] The leading edge 21 is set as the windward surface on the side close to the direction of the fluid flow. The fluid flows toward the trailing edge 22 after passing through the leading edge 21 of the streamlined columnar unit structure 2, and enters the fluid channel formed by the two rows of streamlined structural units, and then enters the next group of fluid channels, thereby reducing the flow resistance of the fluid (air, coolant or hydrogen), ensuring a small pressure difference between the anode and cathode sides of the membrane electrode and uniform temperature distribution in the battery, while reducing the power consumption of the water pump, thereby improving the safety performance and overall output performance of the fuel cell, and ensuring the long-term safe, stable and efficient operation of the fuel cell;

[0099] The trailing edge angle is an acute angle or an arc shape;

[0100] When the trailing edge angle is in an arc shape, the radius of curvature is r, r = 0.02-5 mm, where R ≥ r;

[0101] When the trailing edge angle is an acute angle, the included angle is τ, and 0°<τ<90°.

[0102] In some possible implementations,

[0103] The angle between the fluid flow direction and the chord line 25 is θ, where 0°≤θ≤90°.

[0104] In some possible implementations,

[0105] The distance between two adjacent columns of the streamlined structural units is h, and the distance between two adjacent groups of streamlined columnar unit structures 2 in each column of streamlined structural units is s; wherein, 100 mm>h>0.2 mm, 50 mm>s>0.2 mm.

[0106] The parameter settings in the present invention can also be enlarged or reduced in proportion to the size of the bipolar plate.

[0107] The rear edge 22 of the streamlined columnar unit in each row of streamlined structural units in the utility model can be in an acute angle shape and / or an arc shape.

[0108] like Figure 1 , Figure 7 , Figure 8 As shown,

[0109] The fluid flow direction is the X-axis direction (the length direction of the plate body 1), the width direction of the plate body 1 is the Y-axis direction, and the thickness direction of the plate body 1 is the Z-axis direction. The air flow field lattice structure, the hydrogen flow field lattice structure, and the coolant flow field lattice structure are arranged in the plate body 1 along the Z-axis direction; the inlet air manifold area 100 is interconnected with the corresponding air flow field lattice structure, the inlet hydrogen manifold area 101 is interconnected with the corresponding hydrogen flow field lattice structure, and the inlet coolant manifold area 102 is interconnected with the coolant flow field lattice structure; the inlet hydrogen manifold area 101, the inlet coolant manifold area 102, and the inlet air manifold area 100 are arranged in sequence along the Y-axis direction and staggered in the Z-axis direction;

[0110] The angle between the air flow direction and the chord 25 of the streamlined columnar unit structure 2 in the air flow field lattice structure corresponding to the air inlet distribution area 11 is θ, where 0°≤θ≤90°; the angle between the hydrogen flow direction and the chord 25 of the streamlined columnar unit structure 2 in the hydrogen flow field lattice structure corresponding to the hydrogen flow field is θ, where 0°≤θ≤90°; the angle between the coolant flow direction and the chord 25 of the streamlined columnar unit structure 2 in the coolant flow field lattice structure corresponding to the coolant flow field is θ, where 0°≤θ≤90°;

[0111] like Figure 7 As shown, the inlet coolant manifold area 102 is located in the middle, and the coolant will be able to flow up and down along the Y-axis direction. At this time, the coolant flow field lattice structure will be set as two symmetrical unit groups according to the coolant flow direction, so that the angle between the coolant flow direction of the upper and lower flow channels and the chord 25 of the corresponding streamlined columnar unit structure 2 is θ, where 0°≤θ≤90°;

[0112] After passing through the corresponding lattice structure, the fluid enters the active reaction area for reaction, and then enters the corresponding lattice structure located in the outlet distribution area (air flow field lattice structure, hydrogen flow field lattice structure, coolant flow field lattice structure), and then enters the corresponding outlet air manifold area 103, outlet hydrogen manifold area 104, and outlet coolant manifold area 105 respectively;

[0113] In the utility model, there is no limitation on the positions of the inlet hydrogen manifold area 101, the inlet coolant manifold area 102, the inlet air manifold area 100, the outlet air manifold area 103, the outlet hydrogen manifold area 104, and the outlet coolant manifold area 105, as long as it can be ensured that the flow direction of the fluid is at an angle θ with the corresponding lattice structure and the chord line 25 entering the active reaction area and the corresponding streamlined columnar unit structure 2, wherein 0°≤θ≤90°, and then discharged through the corresponding outlet air manifold area 103 or the outlet hydrogen manifold area 104 or the outlet coolant manifold area 105.

[0114] The streamlined columnar unit structure 2 and the non-streamlined structure in the utility model are used for simulation verification, wherein the maximum thickness of the two structures is the same, and the air flow field pressure drop is compared at different current densities, as shown in FIG. Fig. 9 As shown, the streamlined columnar unit structure 2 in the present invention has a lower air flow field pressure drop than the non-streamlined structure at different current densities.

[0115] The utility model can reduce the flow resistance of the fluid while ensuring uniform distribution of gas and coolant through the arrangement of the streamlined columnar unit structure 2, thereby ensuring uniform temperature distribution in the battery and a small pressure difference on both sides of the membrane electrode, reducing the power consumption of the water pump, thereby improving the overall output performance and safety performance of the fuel cell system, and ensuring long-term safe, stable and efficient operation of the fuel cell;

[0116] The utility model ensures good contact between the anode and cathode plates and the membrane electrode by setting parallel straight flow channels or S-shaped flow channels in the active reaction zone, and the battery stack has a small contact resistance;

[0117] The utility model makes the pressure drop in the active reaction zone more adjustable within the range by cooperating the streamlined columnar unit structure 2 with the parallel straight flow channel or the S-shaped flow channel, thereby ensuring the effective pressure drop in the active reaction zone, and effectively improving the fluid flow, flow resistance and temperature distribution and flow channel drainage in the active reaction zone; improving the overall output performance and safety performance of the fuel cell, ensuring the long-term stable and efficient operation of the fuel cell, and solving the problems of low output performance of the fuel cell, large fluid flow resistance, large contact resistance and uneven fluid distribution.

[0118] The present invention is not limited to the above-mentioned specific implementation modes, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A bipolar plate with a streamlined structure, characterized in that: It comprises a plate body, on which an inlet manifold area, an inlet distribution area, an active reaction area, an outlet distribution area and an outlet manifold area are arranged in sequence; The inlet distribution area and the outlet distribution area are respectively provided with lattice units for guiding the fluid; The lattice unit includes an air flow field lattice structure used in conjunction with an air field, a hydrogen flow field lattice structure used in conjunction with a hydrogen field, and a coolant flow field lattice structure used in conjunction with a coolant flow field.

2. The bipolar plate with a streamlined structure according to claim 1, characterized in that: The air flow field lattice structure, the hydrogen flow field lattice structure and the coolant flow field lattice structure all include a plurality of rows of streamlined structural units arranged in a staggered manner; a fluid channel is formed between two adjacent rows of streamlined structural units.

3. The bipolar plate with a streamlined structure according to claim 1, characterized in that: The inlet manifold area includes an inlet air manifold area, an inlet hydrogen manifold area, and an inlet coolant manifold area; The inlet distribution area includes an air inlet distribution area, a hydrogen inlet distribution area, and a coolant inlet distribution area; The active reaction zone includes an air flow field active reaction zone, a hydrogen flow field active reaction zone, and a coolant main flow channel zone; The outlet distribution area includes an air outlet distribution area, a hydrogen outlet distribution area, and a coolant outlet distribution area; The outlet manifold area includes an outlet air manifold area, an outlet hydrogen manifold area, and an outlet coolant manifold area; The inlet air manifold area, the air inlet distribution area, the air flow field active reaction area, the air outlet distribution area, and the outlet air manifold area are connected in sequence; The inlet hydrogen manifold area, the hydrogen inlet distribution area, the hydrogen flow field active reaction area, the hydrogen outlet distribution area, and the outlet hydrogen manifold area are connected in sequence; The inlet coolant manifold area, the coolant inlet distribution area, the coolant main channel area, and the coolant outlet distribution area are connected in sequence.

4. The bipolar plate with a streamlined structure according to claim 2, characterized in that: The streamlined structural units in each column include a plurality of groups of streamlined columnar unit structures arranged after CFD calculation; the streamlined columnar unit structures in two adjacent groups of streamlined structural units are arranged in a staggered manner.

5. The bipolar plate with a streamlined structure according to claim 4, characterized in that: The cross section of the front edge of the streamlined columnar unit structure is in an arc shape and its curvature radius is R, the angle between the upper and lower curves at the rear edge is the rear edge angle, the straight line connecting the front edge and the rear edge is the chord line, and the length of the chord line is c; The maximum thickness of the streamlined columnar unit structure is t; the maximum thickness is the maximum distance between the upper curve and the lower curve when the line connecting the upper curve and the lower curve is perpendicular to the chord line; Among them, the distance between the section with the maximum distance and the leading edge is Xt; The maximum distance between the median arc line and the chord line in each set of streamlined columnar unit structures is the maximum curvature, and the maximum curvature is f; Among them, the distance between the section where the maximum curvature is located and the leading edge is Xf; The middle arc line is a line connecting the centers of multiple groups of inscribed circles that are inscribed in the upper curve and the lower curve respectively.

6. The bipolar plate with a streamlined structure according to claim 5, characterized in that: c=0.2-10mm, t=0.1-10mm, R=0.1-5mm, f=0-5mm.

7. The bipolar plate with a streamlined structure according to claim 5, characterized in that: The trailing edge angle is an acute angle or an arc shape; When the trailing edge angle is in an arc shape, the radius of curvature is r, r=0.02-5 mm, wherein R≥r.

8. The bipolar plate with a streamlined structure according to claim 5, characterized in that: The angle between the fluid flow direction and the chord line is θ, where 0°≤θ≤90°.

9. A bipolar plate with a streamlined structure according to any one of claims 4 to 8, characterized in that: The distance between two adjacent columns of the streamlined structural units is h, and the distance between two adjacent groups of streamlined columnar unit structures in each column of streamlined structural units is s; wherein, 100mm>h>0.2mm, 50mm>s>0.2mm.

10. The bipolar plate with a streamlined structure according to claim 1, characterized in that: The active reaction zone is provided with parallel flow channels or S-shaped flow channels.

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