Open type air-cooled fuel cell bipolar plate

Abstract

The utility model discloses an open type air-cooled fuel cell bipolar plate, which comprises a cathode side and an anode side, and the runner structure of the anode side is as follows: a hydrogen inlet uniformly disperses gas to the whole reaction area through a plurality of hydrogen runner inlets and is communicated to a hydrogen outlet; the flow channel structure on the cathode side is that a plurality of through air flow channels are arranged, and a plurality of strip-shaped bulges are arranged in the middle of the air flow channels; the hydrogen flow direction is opposite to the air flow direction. The flow channel structures of the cathode and anode bipolar plates are improved, so that the directions of cathode and anode flow fields are almost consistent, hydrogen and air are oppositely transmitted from opposite directions, uniform reaction on the surface of a membrane electrode can be ensured, and the working efficiency of a fuel cell is improved; the long-strip-shaped bulges are arranged in the flow channel of the cathode flow field to form a local reducing structure, so that the air and water transmission capability is effectively enhanced, and the fuel cell is prevented from being flooded by water.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of fuel cell bipolar plates, specifically to a kind of open air-cooled fuel cell bipolar plate;Belong to fuel cell technical field. BACKGROUND

[0002] Fuel cell is a kind of device using fuel and oxidant to generate electricity, can convert chemical energy into electrical energy by electrochemical reaction.In air-cooled fuel cell, hydrogen is used as fuel, oxygen in air is used as oxidant, and its basic structure includes end plate, current collector plate, bipolar plate, membrane electrode and the like.Bipolar plate is one of the key components of fuel cell, mainly to provide flow channel for gas, and the gas is uniformly dispersed by flow field, and reasonable bipolar plate flow field design should be able to ensure the uniform distribution of reactants, temperature and water vapor.

[0003] In open air-cooled fuel cell stack, the anode part of bipolar plate transmits fuel such as hydrogen, which is a fully enclosed design, and the cathode part transmits oxidant such as oxygen, which is an open structure.Usually, a large amount of air is introduced into the cathode part, which provides oxygen required for the cathode reaction, and at the same time can cool the overall stack.As the working temperature of air-cooled fuel cell is relatively low, the generated water is easy to condense into liquid water, causing water flooding of fuel cell.

[0004] The prior art Chinese invention patent CN117954647A discloses a kind of cathode open air-cooled fuel cell bipolar plate, wherein anode flow field distribution area adopts one-to-four structure, main reaction zone adopts wave-shaped flow field, and baffle is arranged in the flow channel of cathode flow field, which is vertically distributed with anode flow field.In the prior art, the flow channels of the main reaction areas of anode and cathode are vertically distributed, which can easily lead to uneven reaction, cause uneven current distribution, increase charge transfer, and although the baffle of cathode can reduce water loss, the baffle also hinders the evaporation of heat, which is not conducive to the temperature control of the stack.

[0005] In view of the above reasons, it is necessary to provide an open air-cooled fuel cell bipolar plate to solve the problems of uneven reaction and serious water flooding. SUMMARY

[0006] To solve the problems of the prior art, the purpose of the utility model is to provide an open air-cooled fuel cell bipolar plate, which improves the working efficiency of fuel cell by improving its structure to ensure uniform reaction on the surface of membrane electrode and effectively avoids water flooding of fuel cell.

[0007] In order to achieve the above goal, the utility model adopts the following technical solutions:

[0008] An open air-cooled type fuel cell bipolar plate, comprising a cathode side and an anode side, the flow channel structure of the anode side is that: the hydrogen inlet is connected to the hydrogen outlet through several hydrogen flow channel inlets to uniformly disperse the gas to the whole reaction area, the flow channel structure of the cathode side is that: several through air flow channels are provided, and several strip-shaped protrusions are arranged in the air flow channels, the hydrogen flow channel is parallel to the air flow channel, and the hydrogen flow direction is opposite to the air flow direction.

[0009] Preferably, the aforementioned cathode side and anode side are integrated on the same graphite plate, metal plate or composite plate.

[0010] More preferably, the aforementioned hydrogen inlet and hydrogen outlet are semicircular, rectangular or square.

[0011] More preferably, a sealing gasket is arranged around the aforementioned hydrogen inlet and hydrogen outlet, and a groove is formed on the edge of the anode side to install the sealing gasket, so as to prevent hydrogen leakage and hydrogen-oxygen intercommunication.

[0012] More preferably, each hydrogen inlet is connected to 3-5 hydrogen flow channels, the width of the hydrogen flow channel is 0.2-2.5mm, the depth is 0.1-2mm, the ridge width is 0.2-2.5mm, and the ridge height is consistent with the edge height of the bipolar plate.

[0013] More preferably, the width of the air flow channel of the aforementioned cathode side is 0.2-2.5mm, the depth is 0.5-5mm, and the ridge width is 0.2-2.5mm; the width of the strip-shaped protrusion in the air flow channel is 30-60% of the width of the air flow channel, and the length is 5-40mm, which can effectively increase the drainage capacity of the cathode and improve the utilization rate of the gas.

[0014] More preferably, the strip-shaped protrusions are arranged at equal intervals in the air flow channel, and the cross section forms a variable diameter structure, preferably a structure with thin ends and thick middle, such as a shuttle-shaped structure, an elliptical structure and the like, which is a suitable choice, and such a structure design is beneficial to the cathode to discharge water vapor and avoid fuel cell flooding.

[0015] The utility model discloses the beneficial effect lies in:

[0016] (1) by improving the flow channel structure of the cathode and anode bipolar plate, the conventional technology of the flow field perpendicular to each other is abandoned, the flow field direction of the cathode and anode of the utility model is almost consistent, hydrogen and air are transmitted from opposite directions, which can ensure the uniformity of the reaction on the membrane electrode surface and improve the working efficiency of the fuel cell.

[0017] (2) Because the operating temperature of the air-cooled stack is low, a large amount of water vapor is easily generated under high current density, if not promptly discharged, liquid water is easily formed, fuel cell flooding is caused, and fuel cell operation failure is caused. In the utility model, the strip-shaped protrusion is arranged in the flow channel of the cathode flow field, the channel is locally narrowed, the air flow rate is increased, the transmission of air and water is beneficial, water vapor is taken away, and fuel cell flooding is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the schematic diagram of the anode flow field structure of the bipolar plate of the utility model;

[0019] Figure 2 is the schematic diagram of the cathode flow field structure of the bipolar plate of the utility model;

[0020] Figure 3 is the schematic diagram of the overall structure of the bipolar plate of the utility model.

[0021] The meanings of the reference signs in the drawing are as follows: 1, hydrogen gas inlet, 2, hydrogen gas outlet, 3, hydrogen flow channel, 4, sealing gasket, 5, air flow channel, 6, protrusion. DETAILED DESCRIPTION

[0022] The utility model will be specifically introduced in combination with the drawings and specific embodiments.

[0023] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship shown in the drawing, and is only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, a particular orientation and operation, therefore, it cannot be understood as a limitation on the utility model. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0024] The embodiment discloses an open air-cooled fuel cell bipolar plate, which comprises a cathode side and an anode side; the cathode side and the anode side are integrated on the front and back surfaces of the same graphite plate, metal plate or composite plate material, the hydrogen flow direction of the anode side is opposite to the air flow direction of the cathode side, that is, the two kinds of gases constitute opposite transmission, can ensure that the reaction on the surface of the membrane electrode is uniform, and improves the working efficiency of the fuel cell.

[0025] As Figure 1As shown, the flow channel structure of the anode side includes: hydrogen gas inlet 1, several hydrogen gas flow channels 3 and hydrogen gas outlet 2, and the hydrogen gas inlet 1 and the hydrogen gas outlet 2 are both smaller semicircular shapes, which can also be replaced by rectangular or square shapes. Several hydrogen gas flow channel 3 inlets are connected at the hydrogen gas inlet 1, generally 3-5 inlets are provided, and the hydrogen gas is uniformly dispersed to the entire reaction zone through the flow channel inlets, and the hydrogen gas flow direction is as shown by the arrow in the middle. Figure 1 In actual structural design, the hydrogen gas inlet 1 should not be too large, so as to avoid that the hydrogen gas transmission path is too long and the hydrogen gas is not uniformly distributed. As a preferred, the width of the hydrogen gas flow channel 3 is 0.2-2.5mm, the depth is 0.1-2mm, the ridge width is 0.2-2.5mm, and the ridge height is consistent with the edge height of the bipolar plate.

[0026] As shown in the figure, Figure 2 The flow channel structure of the cathode side is: several through-type air flow channels 5, as described above, the air flow channels 5 are consistent with the direction of the hydrogen gas main flow channel. The width of the air flow channel 5 is 0.2-2.5mm, the depth is 0.5-5mm, the ridge width is 0.2-2.5mm, several strip-shaped protrusions 6 are arranged in the middle of the air flow channel 5, the width of the strip-shaped protrusion 6 is 30-60% of the width of the flow channel, and the length is 5-40mm. Moreover, the cross section of the strip-shaped protrusion 6 is a variable-diameter structure, which is preferably a structure with thin ends and thick middle, such as a shuttle-shaped structure, an elliptical structure, etc., which can effectively increase the water drainage capacity of the cathode, improve the utilization rate of the gas, and avoid fuel cell flooding.

[0027] In order to prevent hydrogen gas leakage and hydrogen-oxygen intermixing, sealing pads 4 are arranged around the hydrogen gas inlet 1 and the hydrogen gas outlet 2, and grooves are formed at the edges of the anode side to install the sealing pads 4.

[0028] In summary, the flow channel structure of the anode and cathode bipolar plates is improved, the hydrogen gas and the air are transmitted from opposite directions, the reaction on the surface of the membrane electrode can be ensured to be uniform, the working efficiency of the fuel cell is improved, the strip-shaped protrusions 6 are arranged in the flow channel of the cathode flow field to form a local variable-diameter structure, the transmission capacity of the air and the water is effectively enhanced, the effective drainage is promoted, the fuel cell flooding is avoided, and the use performance is ensured.

[0029] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0030] The basic principle, main features and advantages of the present application are shown and described above. The skilled in the art should understand that the above examples do not limit the present application in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. An open air-cooled type fuel cell bipolar plate comprising a cathode side and an anode side, characterized by, The anode side flow channel structure is that hydrogen gas is uniformly dispersed to the whole reaction area through hydrogen gas flow channel inlets from a hydrogen gas inlet and connected to a hydrogen gas outlet; the cathode side flow channel structure is that there are several through air flow channels, and several long strip-shaped protrusions are arranged in the middle of the air flow channels; the hydrogen gas flow channels are parallel to the air flow channels, and the hydrogen gas flow direction is opposite to the air flow direction.

2. An open air-cooled fuel cell bipolar plate according to claim 1, wherein The cathode side and the anode side are integrated on the same graphite plate, metal plate or composite plate.

3. The open air-cooled fuel cell bipolar plate of claim 1, wherein The hydrogen gas inlet and the hydrogen gas outlet are semicircular, rectangular or square.

4. An open air-cooled fuel cell bipolar plate according to claim 3, wherein The hydrogen gas inlet and the hydrogen gas outlet are each provided with a sealing gasket, and the edge of the anode side plate is recessed to install the sealing gasket.

5. The open air-cooled fuel cell bipolar plate of claim 1, wherein The hydrogen gas inlet is connected to 3-5 hydrogen gas flow channels, the width of the hydrogen gas flow channel is 0.2-2.5 mm, the depth is 0.1-2 mm, the ridge width is 0.2-2.5 mm, and the ridge height is consistent with the edge height of the bipolar plate.

6. The open air-cooled fuel cell bipolar plate of claim 1, wherein The width of the air flow channel of the cathode side is 0.2-2.5 mm, the depth is 0.5-5 mm, and the ridge width is 0.2-2.5 mm.

7. An open air-cooled fuel cell bipolar plate according to claim 6, wherein The width of the long strip-shaped protrusion is 30-60% of the width of the flow channel, and the length is 5-40 mm.

8. An open air-cooled fuel cell bipolar plate according to claim 6, wherein The cross section of the long strip-shaped protrusion is a variable diameter structure.

9. An open air-cooled fuel cell bipolar plate according to claim 6, wherein The cross section of the long strip-shaped protrusion is a structure with thin ends and thick middle.

10. The open air-cooled fuel cell bipolar plate of claim 6, wherein The long strip-shaped protrusions are arranged at equal intervals in the air flow channel.

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