A fuel cell bipolar plate structure with high active area utilization

Abstract

The application provides a fuel cell bipolar plate structure with high active area utilization, which comprises a manifold port area at two ends and an active reaction area in the middle, and a distribution area between the manifold port area and the active reaction area; the manifold port area and the active reaction area are connected through the distribution area; the area of the active reaction area is 60-68% of the plate surface of the bipolar plate structure; the manifold port area and the distribution area are connected through a transition inclined port, the transition inclined port comprises a plurality of interval arranged gas flow channels, and the gas flow channels are used for connecting the manifold port area and the distribution area; the distribution area is in a trapezoidal structure, and the distribution area comprises a plurality of round dot-shaped protrusions and a plurality of curved long strip protrusion structures. The technical scheme of the application solves the problems of the graphite bipolar plate, such as large distribution area proportion, small active area, and low bipolar plate surface utilization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular, especially relates to a high active area utilization rate of fuel cell bipolar plate structure. BACKGROUND

[0002] As the core component of fuel cell, bipolar plate plays an important role in distributing gas, conducting electricity, conducting heat, draining water and other important functions in fuel cell, and its performance is largely determined by the structure of the bipolar plate distribution area and flow field area.

[0003] Single cell is connected in series to form a stack, and each cell unit is composed of a bipolar plate and a membrane electrode. Generally, a groove is formed on the surface of the plate to form a flow field. The flow field is the reaction active area, and the reaction gas enters the active area from the manifold after passing through the bipolar plate distribution area. The fuel cell generates chemical reaction to generate electricity.

[0004] At present, the design of graphite bipolar plate needs to consider fluid distribution, flow resistance, water drainage and other problems, which leads to a large proportion of bipolar plate distribution area, which to some extent compresses the area of active area and reduces the utilization rate of bipolar plate surface. SUMMARY

[0005] According to the above-mentioned technical problems of graphite bipolar plate that the distribution area occupies a large proportion and the active area is small, the utilization rate of bipolar plate surface is low, a high active area utilization rate of fuel cell bipolar plate structure is provided, which mainly utilizes the special design of the manifold port area and the distribution area to improve the utilization rate of the active area of the bipolar plate as much as possible under the premise of considering fluid distribution, flow resistance, contact area and supporting force of the bipolar plate.

[0006] The technical means adopted by the present application is as follows:

[0007] A high active area utilization rate of fuel cell bipolar plate structure, comprising a manifold port area at both ends and an active reaction area in the middle, and a distribution area between the manifold port area and the active reaction area; the manifold port area and the active reaction area are connected through the distribution area; the area of the active reaction area is 60-68% of the surface of the bipolar plate structure;

[0008] The manifold port area and the distribution area are connected through a transition bevel, and the transition bevel comprises a plurality of spaced gas flow channels, which are used to connect the manifold port area and the distribution area;

[0009] The distribution area is a trapezoidal structure, and the distribution area comprises a plurality of circular dot protrusions and a plurality of curved strip protrusion structures.

[0010] Further, the transition bevel is inclined relative to the width direction of the bipolar plate structure from the manifold port area to the distribution area, and the inclination angle is 10-45°.

[0011] Further, the distribution area is connected to the transition bevel through a reverse gas port, the width of the reverse gas port is 0.5-3 mm, the length of the gas flow channel is 5-15 mm, and the interval distance between adjacent two gas flow channels is 0.5-2 mm.

[0012] Further, the corresponding height h of the trapezoidal distribution area is 5-20 mm, the lower base L is 350-450 mm, and the included angle between the two waists and the length direction of the bipolar plate structure is 20-60°.

[0013] Further, the surface between the circular dot-shaped protrusions and the curved long strip protrusion structure in the distribution area is a concave structure, and the depth of the concave structure is 0.1-0.5 mm.

[0014] Further, the radius of the circular dot-shaped protrusion is 0.2-2 mm, and the interval distance between adjacent two circular dot-shaped protrusions is 1-2 mm.

[0015] Further, the distribution area includes 1-10 curved long strip protrusion structures, the length of the curved long strip protrusion structure is 10-30 mm, the curved long strip protrusion structure is composed of two connected straight line segments, the included angle between the two straight line segments is 30-120°, and the two ends of the curved long strip protrusion structure are semicircular.

[0016] Further, the active reaction area includes a fluid channel and a flow channel ridge, and the longitudinal section of the fluid channel is semicircular.

[0017] Further, the bipolar plate structure includes an anode plate and a cathode plate, and the anode plate and the cathode plate are respectively provided with the manifold port area, the distribution area and the active reaction area.

[0018] One side surface of the active reaction area on the anode plate is provided with a cooling liquid flow field, and the other side surface is provided with a hydrogen gas flow field; one side surface of the active reaction area on the cathode plate is a plane, and the other side is provided with an air flow field; and the side surface of the anode plate provided with the cooling liquid flow field is oppositely fitted with the plane on the cathode plate to form the bipolar plate structure.

[0019] The radius of the fluid channel in the air flow field is greater than the radius of the fluid channel in the hydrogen gas flow field; and the flow channel ridge in the hydrogen gas flow field corresponds to the flow channel ridge in the air flow field.

[0020] Further, the fluid passage radius in the hydrogen flow field is 1-3mm, and the fluid passage radius in the air flow field is 3-5mm.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] The high active area utilization rate fuel cell bipolar plate structure provided by the present application has the following advantages: the transition part of the manifold port area and the distribution area is designed as an inclined port, the distribution area is compressed, a plurality of dot-shaped protrusions and curved strip protrusions are arranged in the distribution area, the area of the distribution area is greatly compressed, the flow distribution is balanced, and the flow resistance is reduced, the bipolar plate structure provided by the present application facilitates water drainage of the fuel cell and avoids water accumulation, the area of the distribution area is compressed, the proportion of the active area in the whole bipolar plate surface is increased, and the utilization rate of the bipolar plate is improved.

[0023] Based on the above reasons, the present application can be widely promoted in the field of fuel cells. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The high active area utilization rate fuel cell bipolar plate structure of the present application is shown in the schematic diagram.

[0026] Figure 2 The cross-sectional view of the anode plate and the cathode plate of the present application is shown in the schematic diagram.

[0027] Figure 3 The front view of the high active area utilization rate fuel cell bipolar plate structure of the present application is shown in the schematic diagram.

[0028] Figure 4 The transition inclined port structure of the present application is shown in the schematic diagram.

[0029] Figure 5 The gas flow passage structure of the present application is shown in the schematic diagram.

[0030] Figure 6 The distribution area structure of the present application is shown in the schematic diagram.

[0031] Figure 7 The assembled state of the two pieces of the bipolar plate structure of the present application is shown in the schematic diagram.

[0032] In the figure: 1, anode plate; 2, cathode plate; 3, hydrogen gas flow field; 4, cooling liquid flow field; 5, plane; 6, air flow field; 7, total pipe mouth area; 8, distribution area; 9, active reaction area; 10, transition bevel; 11, gas flow channel; 12, round dot protrusion; 13, curved long strip protrusion structure; 14, air outlet; 15, ridge; 16, fuel channel. DETAILED DESCRIPTION

[0033] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0034] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0036] Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in the various embodiments described herein are not meant to limit the scope of the present application. It should also be understood that the size of the various parts shown in the drawings can not be to scale, and that the drawings are intended to conceptually illustrate the structures and procedures described herein. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the description of the present application. In all examples shown and discussed herein, any specific value should be interpreted as merely illustrative, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that similar reference numbers and letters in the following drawings represent similar items, and therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0037] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0038] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0039] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0040] Example 1

[0041] like Figures 3-6 As shown, the present invention provides a fuel cell bipolar plate structure with high active area utilization, including a main inlet region 7 at both ends and an active reaction region 9 in the middle, and a distribution region 8 between the main inlet region 7 and the active reaction region 9; the main inlet region 7 and the active reaction region 9 are connected through the distribution region 8; the area of ​​the active reaction region 9 is 60-68% of the surface area of ​​the bipolar plate structure; preferably, the area of ​​the active reaction region 9 is 65% of the surface area of ​​the bipolar plate structure.

[0042] The total pipe mouth area 7 is communicated with the distribution area 8 through a transition bevel 10, the transition bevel 10 comprises a plurality of interval arranged gas flow channels 11, the gas flow channels 11 are used for communicating the total pipe mouth area 7 with the distribution area 8; the transition bevel 10 increases the area of the reaction gas flow area, thereby reducing the flow resistance, facilitating the selection of the air compressor; the ridge between the adjacent two gas flow channels 11 can play a supporting role.

[0043] The distribution area 8 is a trapezoidal structure, facilitating fluid distribution, reducing the area of the distribution area 8, and increasing the area of the total pipe mouth area 7; the distribution area 8 comprises a plurality of dot-shaped protrusions 12 and a plurality of curved strip protrusion structures 13, the two structures can play the role of throttling and supporting, so that the fluid is uniformly distributed before entering the active reaction area 9, and the bipolar plate structure can not collapse and break under a certain pressure.

[0044] Further, the transition bevel 10 is inclined relative to the width direction of the bipolar plate structure from the total pipe mouth area 7 to the distribution area 8, and the inclination angle is 10-45°.

[0045] Further, the distribution area 8 is communicated with the transition bevel 10 through a reverse gas port 14, the width of the reverse gas port 14 is 0.5-3mm; the length of the gas flow channel 11 is 5-15mm, and the interval distance between the adjacent two gas flow channels 11 is 0.5-2mm.

[0046] Further, the corresponding trapezoidal height h of the distribution area 8 is 5-20mm, the lower base L is 350-450mm, and the included angle between the two waists and the length direction of the bipolar plate structure is 20-60°.

[0047] Further, the surface between the dot-shaped protrusions 12 and the curved strip protrusion structures 13 in the distribution area 8 is a concave structure, facilitating the smooth passage of fluid through the distribution area 8, and the depth of the concave structure is 0.1-0.5mm.

[0048] Further, the radius of the dot-shaped protrusion 12 is 0.2-2mm, the interval between the adjacent two dot-shaped protrusions 12 is 1-2mm, and the dot-shaped protrusions 12 are distributed irregularly.

[0049] Further, the distribution area 8 comprises 1-10 curved long strip raised structures 13, and the number is set according to the size of the distribution area 8 and the flow interception demand; the length of the curved long strip raised structure 13 is 10-30 mm, the curved long strip raised structure 13 is composed of two connected straight line segment structures, the included angle between the two straight line segment structures is 30-120°, and the two ends of the curved long strip raised structure 13 are semicircular; the curved long strip raised structure 13 designed in the application can play the roles of flow guiding and supporting, and can make the fluid distribution more uniform.

[0050] Further, the active reaction area 9 comprises a fluid passage and a flow channel ridge.

[0051] Further, as shown in Figures 1-2 , 7, the bipolar plate structure comprises an anode plate 1 and a cathode plate 2; the anode plate 1 and the cathode plate 2 are respectively provided with the main pipe port area 7, the distribution area and the active reaction area 9;

[0052] One side surface of the active reaction area 9 on the anode plate 1 is provided with a cooling liquid flow field 4 for flowing cooling liquid, and the other side surface is provided with a hydrogen gas flow field 3 for flowing hydrogen gas; one side surface of the active reaction area 9 on the cathode plate 2 is a plane 5, and the other side is provided with an air flow field 6 for flowing air; the side surface of the anode plate 1 provided with the cooling liquid flow field 4 is oppositely attached to the plane 5 on the cathode plate 2 to form the bipolar plate structure, and such a structure design can prevent the contact surface of the bipolar plate from being dislocated due to processing problems, thereby ensuring a small contact resistance;

[0053] The radius of the fluid passage in the air flow field 6 is greater than the radius of the fluid passage in the hydrogen gas flow field 3; the flow channel ridge in the hydrogen gas flow field 3 corresponds to the flow channel ridge in the air flow field 6 in position;

[0054] When the bipolar plate structure is assembled into a fuel cell, the flow channel ridges in the hydrogen gas flow field 3 and the air flow field 6 of adjacent two bipolar plate structures are assembled in a ridge-to-ridge 15 mode (i.e., the flow channel ridges in the hydrogen gas flow field 3 and the air flow field 6 are correspondingly attached), and the fluid passages of the hydrogen gas flow field 3 and the air flow field 6 of adjacent two bipolar plate structures can form a fuel passage 16; in the application, the radius of the fluid passage in the air flow field 6 is greater than the radius of the fluid passage in the hydrogen gas flow field 3, which can increase the flow amount of the reaction flow gas, and at the same time, since the ridge-to-ridge 15 mode is adopted for assembly, the contact between adjacent two bipolar plate structures is good, the contact resistance is reduced, and the battery performance is improved.

[0055] Further, the fluid passage radius in the hydrogen flow field 3 is 1-3 mm, and the fluid passage radius in the air flow field 6 is 3-5 mm.

[0056] When the high active area utilization rate fuel cell bipolar plate structure of the application is in operation, the gas enters the bipolar plate structure through the manifold port area 7, and then enters the distribution area 8 through the gas flow channel 11 on the transition inclined port 10 between the manifold port area 7 and the distribution area 8 and the counter gas port 14.

[0057] The distribution area 8 is provided with dot-shaped protrusions 12 and curved long strip protrusion structures 13, the dot-shaped protrusions 12 are kept at a certain distance from each other, which disperses the gas flow entering the distribution area and uniformly distributes the gas, and plays a role of flow guide; at the same time, the dot-shaped protrusions 12 and the curved long strip protrusion structures 13 can play a role of structural support when an external force is applied to the whole plate surface of the bipolar plate, increase the support strength, so that the distribution area 8 does not collapse, the curved long strip protrusion structure 13 is designed by two straight line segments at a certain angle, which can play a role of flow interception, so that the gas is more uniformly distributed before entering the active reaction area 9, and the design of the distribution area 8 of the application can reduce the space ratio of the distribution area 8 in the whole plate surface, thereby increasing the space ratio of the active reaction area 9.

[0058] After the gas passes through the distribution area 8, it enters the active reaction area 9, when the bipolar plate structure of the application is assembled into a fuel cell, the active reaction areas 9 of two adjacent bipolar plate structures are assembled in a ridge-to-ridge 15 manner, which increases the stability of the flow field structure, so that the assembled fuel cell is not easy to collapse and deform, and the reaction gas can perform chemical reaction in the fuel channel 16 to generate electricity.

[0059] The design of the bipolar plate structure first considers the active area requirement to meet the power of the stack, the selection of the active area region is closely related to the position of the uniform gas distribution region and the uniform temperature distribution region of the stack, the power demand of the fuel cell is increasing, and the requirement for the active area of the bipolar plate is increasing, the high active area utilization rate fuel cell bipolar plate structure provided by the application can greatly compress the area of the distribution area, improve the proportion of the active reaction area, and increase the utilization rate of the plate surface while meeting the above basic requirements of the bipolar plate design.

[0060] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A bipolar plate structure for a fuel cell with high utilization of the active region, characterized in that, It includes a main inlet area at both ends and an active reaction area in the middle, as well as a distribution area between the main inlet area and the active reaction area; the main inlet area and the active reaction area are connected through the distribution area; the area of ​​the active reaction area is 60-68% of the surface area of ​​the bipolar plate structure. The main pipe area and the distribution area are connected by a transition bevel. The transition bevel includes several spaced gas flow channels that connect the main pipe area and the distribution area. The distribution area has a trapezoidal structure and includes several dot-shaped protrusions and several curved elongated protrusions. The dot-shaped protrusions maintain a certain distance from each other, which disperses the airflow entering the distribution area and distributes the gas evenly, thus playing a guiding role. The transition bevel is inclined from the main pipe area to the distribution area relative to the width direction of the bipolar plate structure, with an inclination angle of 10~45°. The trapezoidal height h corresponding to the distribution area is 5~20mm, the lower base L is 350~450mm, and the angle between the two sides and the bipolar plate structure in the length direction is 20~60°. The distribution area includes 1 to 10 of the aforementioned curved elongated protrusion structures; The length of the curved elongated protrusion is 10~30mm. The curved elongated protrusion is composed of two connected straight line segments. The included angle between the two straight line segments is 30~120°. The two ends of the curved elongated protrusion are semi-circular. The curved elongated protrusion plays a role in intercepting the flow, so that the gas is evenly distributed before entering the active reaction zone.

2. The fuel cell bipolar plate structure with high active area utilization according to claim 1, characterized in that, The distribution area is connected to the transition oblique opening through a backflow port, the width of which is 0.5~3mm; the length of the gas flow channel is 5~15mm, and the interval between two adjacent gas flow channels is 0.5~2mm.

3. The fuel cell bipolar plate structure with high active area utilization according to claim 1, characterized in that, Within the distribution area, the surface located between the dot-shaped protrusion and the curved elongated protrusion structure is a recessed structure, and the depth of the recessed structure is 0.1~0.5mm.

4. The fuel cell bipolar plate structure with high active area utilization according to claim 1, characterized in that, The radius of the dot-shaped protrusion is 0.2~2mm, and the distance between two adjacent dot-shaped protrusions is 1~2mm.

5. The fuel cell bipolar plate structure with high active area utilization according to claim 1, characterized in that, The active reaction zone includes a fluid channel and a flow channel ridge, and the longitudinal cross-section of the fluid channel is semi-circular.

6. The fuel cell bipolar plate structure with high active area utilization according to claim 5, characterized in that, The bipolar plate structure includes an anode plate and a cathode plate; the anode plate and the cathode plate are respectively provided with the main pipe opening area, the distribution area and the active reaction area; A coolant flow field is provided on one side of the active reaction zone on the anode plate, and a hydrogen flow field is provided on the other side; one side of the active reaction zone on the cathode plate is a plane, and an air flow field is provided on the other side; the side of the anode plate with the coolant flow field is in contact with the plane on the cathode plate to form the bipolar plate structure. The radius of the fluid channel in the air flow field is larger than the radius of the fluid channel in the hydrogen flow field; the position of the flow channel ridge in the hydrogen flow field corresponds to the position of the flow channel ridge in the air flow field.

7. The fuel cell bipolar plate structure with high active area utilization according to claim 6, characterized in that, The radius of the fluid channel in the hydrogen flow field is 1~3mm, and the radius of the fluid channel in the air flow field is 3~5mm.

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