A liquid-cooled bipolar plate with cathode reflow self-humidification

Abstract

The present invention discloses a liquid-cooled bipolar plate with cathode reflow self-humidification, wherein one side of the cathode plate is configured to form an air flow channel, and the other side is configured to be a plane; one side of the anode plate is configured to form a hydrogen flow channel, and the other side is configured to be a ridge structure; the cathode plate and the anode plate are matched and connected so that the plane and the ridge structure match to form a cooling liquid flow channel, and one end of the cathode plate and the anode plate are respectively provided with a plurality of vertically spaced air inlets and outlets, which are respectively connected with the air flow channel inlets and outlets to form an air reflow flow channel, and the other ends of the cathode plate and the anode plate are provided with a hydrogen inlet and outlet and a cooling liquid inlet and outlet; the air inlet and outlet are respectively connected with the air inlet and outlet of the fuel cell stack, so that the air inlet and outlet of the fuel cell stack are interconnected, and the cooling liquid inlet and outlet are connected through the cooling liquid flow channel; the present invention effectively reduces the flow resistance of the flow channel relative to the serpentine flow channel by arranging the inlet and outlet of the same medium on the same side of the bipolar plate, and can enable the fuel cell stack cathode to achieve the effect of self-humidification.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen fuel cells, and more specifically, relates to a cathode reflux self-humidifying liquid-cooled bipolar plate. Background Art

[0002] As hydrogen fuel cells gradually enter the market and are put into use, cost competition for fuel cells is becoming increasingly fierce, and the requirements for the size and weight of fuel cell systems are becoming increasingly smaller. The humidifier system of a fuel cell system occupies a relatively large portion of the entire system space, resulting in relatively high system costs. Furthermore, the numerous corners in the return pipe also place stringent requirements on the air compressor. If the fuel cell stack can humidify itself without a humidifier, thus eliminating the need for a humidifier, the entire system architecture will be simplified, reducing size, weight, and various costs. Technical requirements for the air compressor, such as power and pressure ratio, will also be reduced, thereby improving system efficiency. Summary of the Invention

[0003] The main purpose of the present invention is to provide a liquid-cooled bipolar plate with cathode reflux self-humidification, so that the cathode of the battery stack can achieve the effect of self-humidification.

[0004] According to a first aspect of the present invention, there is provided a cathode reflow self-humidifying liquid-cooled bipolar plate, comprising:

[0005] a cathode plate, wherein one side of the cathode plate is configured to form an air flow channel and the other side is configured to be flat; a plurality of vertically arranged first air inlets and first air outlets are provided on one side of the air flow channel, the first air inlet is connected to the air flow channel inlet, and the first air outlet is connected to the air flow channel outlet to form an air return flow channel; and a first hydrogen inlet, a first coolant inlet, a first coolant outlet, and a first hydrogen outlet are provided on an end of the cathode plate away from the first air inlet and the first air outlet;

[0006] an anode plate, wherein one side of the anode plate is configured to form a hydrogen flow channel and the other side is configured to have a ridge structure, a plurality of second air inlets and a second air outlet are provided on one side of the hydrogen flow channel, and an end of the anode plate away from the second air inlet and the second air outlet is provided with a second hydrogen inlet, a second coolant inlet, a second coolant outlet, and a second hydrogen outlet arranged in sequence;

[0007] The first air inlet and the first air outlet are respectively connected to the stack air inlet and the stack air outlet, so that the stack air inlet and the stack air outlet are interconnected;

[0008] The cathode plate and the anode plate are connected in a coordinated manner so that the plane and the ridge structure abut against each other to form a coolant flow channel; the first coolant inlet and the first coolant outlet are connected through the coolant flow channel.

[0009] In a specific embodiment of the present invention, a plurality of the first air inlets and a plurality of the first air outlets are arranged in an array with intervals therebetween; a plurality of the second air inlets and a plurality of the second air outlets are arranged in an array with intervals therebetween.

[0010] In a specific embodiment of the present invention, the first hydrogen inlet corresponds to the second hydrogen inlet, the first hydrogen outlet corresponds to the second hydrogen outlet, the first air inlet corresponds to the second air inlet, the first air outlet corresponds to the second air outlet, the first coolant inlet corresponds to the second coolant inlet, and the first coolant outlet corresponds to the second coolant outlet.

[0011] In a specific embodiment of the present invention, the air return flow channel includes a plurality of flow channel groups, one of the flow channel groups includes three branch flow channels, and the branch flow channels are U-shaped structures.

[0012] In a specific embodiment of the present invention, the inlet and the outlet of the branch flow channel are respectively connected to the first air inlet and the first air outlet.

[0013] In a specific embodiment of the present invention, a hydrogen inlet distribution area and a hydrogen outlet distribution area are provided on one side of the hydrogen flow channel, the second hydrogen inlet is connected to the hydrogen flow channel through the hydrogen inlet distribution area, and the second hydrogen outlet is connected to the hydrogen flow channel through the hydrogen outlet distribution area.

[0014] In a specific embodiment of the present invention, the hydrogen inlet distribution area and the hydrogen outlet distribution area are arranged symmetrically.

[0015] In a specific embodiment of the present invention, the first coolant inlet and the first coolant outlet are located between the first hydrogen inlet and the first hydrogen outlet, and the first coolant inlet and the first hydrogen inlet are symmetrically arranged between the first coolant outlet and the first hydrogen outlet; the second coolant inlet and the second coolant outlet are located between the second hydrogen inlet and the second hydrogen outlet, and the second coolant inlet and the second hydrogen inlet are symmetrically arranged between the second coolant outlet and the second hydrogen outlet.

[0016] In a specific embodiment of the present invention, the hydrogen flow channel is an n-type structure, and the coolant flow channel is a U-type structure.

[0017] In a specific embodiment of the present invention, the cathode plate and the anode plate are made of graphite.

[0018] One of the above technical solutions of the present invention has at least one of the following advantages or beneficial effects:

[0019] This cathode reflow self-humidification liquid-cooled bipolar plate can effectively reduce the flow resistance of the air flow channel, hydrogen flow channel and coolant flow channel by arranging the inlet and outlet of the same medium entering the bipolar plate on the same side of the cathode plate and the anode plate, and widen the design length of the bipolar plate; and by dividing the air flow channel on the cathode plate into multiple flow channel groups, multiple air reflow flow channels are formed, and the stack air inlet and the stack air outlet are interconnected, so that the dry gas at the air flow channel inlet can transfer moisture to the high-humidity gas at the air flow channel outlet, and the moisture at the air flow channel outlet not only penetrates to the air flow channel inlet through the gas diffusion layer, but also penetrates to the air flow channel inlet of the next flow channel group through the gas diffusion layer to reflow humidify it, and at the same time it also receives reflow humidification from the air flow channel outlet, and the flow channel groups humidify each other, so that the stack cathode achieves the effect of self-humidification. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0021] Figure 1 This is a schematic structural diagram of a cathode plate surface in one embodiment of the present invention;

[0022] Figure 2 is a perspective view of a cathode plate surface according to one embodiment of the present invention;

[0023] Figure 3 This is a schematic structural diagram of an anode plate surface in one embodiment of the present invention;

[0024] Figure 4 is a perspective view of an anode plate surface according to one embodiment of the present invention;

[0025] Figure 5 is a schematic structural diagram of a coolant flow channel surface in one embodiment of the present invention;

[0026] Figure 6 is a perspective view of a coolant flow channel surface in one embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the cutaway structure of an embodiment of the present invention;

[0028] Figure 8 It is a schematic diagram of the cut structure of an embodiment of the present invention from another angle. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0031] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be internal communication between two elements, indirect communication, or an interactive relationship between two elements.

[0034] The following disclosure provides many different embodiments or examples for implementing different solutions of the present invention.

[0035] Reference Figures 1 to 8 As shown, a cathode reflow self-humidification liquid-cooled bipolar plate is provided, comprising:

[0036] A cathode plate 1, one side of the cathode plate 1 is configured to form an air flow channel 11, and the other side is configured to be flat. One side of the air flow channel 11 is provided with a plurality of vertically arranged first air inlets 12 and first air outlets 13. The first air inlets 12 are connected to the air flow channel inlet, and the first air outlets 13 are connected to the air flow channel outlet to form an air return flow channel. The end of the cathode plate 1 away from the first air inlet 12 and the first air outlet 13 is provided with a first hydrogen inlet 14, a first coolant inlet 16, a first coolant outlet 17, and a first hydrogen outlet 15 arranged in sequence;

[0037] Anode plate 2, one side of the anode plate 2 is configured to form a hydrogen flow channel 21, and the other side is configured to form a ridge structure 28. One side of the hydrogen flow channel 21 is provided with a plurality of second air inlets 22 and second air outlets 23. The end of the anode plate 2 away from the second air inlets 22 and second air outlets 23 is provided with a second hydrogen inlet 24, a second coolant inlet 26, a second coolant outlet 27 and a second hydrogen outlet 25 arranged in sequence;

[0038] The first air inlet 12 and the first air outlet 13 are respectively connected to the stack air inlet and the stack air outlet, so that the stack air inlet and the stack air outlet are interconnected;

[0039] The cathode plate 1 and the anode plate 2 are connected in a coordinated manner so that the flat surface and the ridge structure 28 abut against each other to form a coolant flow channel 29 ; the first coolant inlet 16 and the first coolant outlet 17 are connected through the coolant flow channel 29 .

[0040] In this embodiment, the cathode reflow self-humidification liquid-cooled bipolar plate can effectively reduce the flow resistance of the air flow channel 11, the hydrogen flow channel 21, and the coolant flow channel 29 by arranging the inlet and outlet of the same medium entering the bipolar plate on the same side of the cathode plate 1 and the anode plate 2, thereby widening the design length of the bipolar plate, increasing the effective area ratio of the bipolar plate, and facilitating the assembly of the fuel cell stack; and the fuel cell stack air inlet and the fuel cell stack air outlet are interconnected, so that the dry gas at the air flow channel inlet 112 can transfer moisture with the high-humidity gas at the air flow channel outlet 113, thereby humidifying the dry gas. In addition to permeating the air flow channel outlet 113 through the gas diffusion layer to the air flow channel inlet 112, the moisture at the air flow channel outlet 113 also permeates through the gas diffusion layer to the air flow channel inlet 112 of the next flow channel group 111 for reflow humidification. At the same time, it also receives reflow humidification from the air flow channel outlet 113 of the same flow channel group 111. The flow channel groups 111 humidify each other, so that the fuel cell stack cathode achieves a self-humidification effect. The backflow humidification between the air flow channels 11 eliminates the need for a humidifier, thereby simplifying the architecture of the entire battery system, reducing the volume, weight and various costs, and reducing the technical requirements for the power, pressure ratio and other technical requirements of the air compressor, which will also improve the working efficiency of the battery system.

[0041] Furthermore, the first hydrogen inlet 14 corresponds to the second hydrogen inlet 24 , the first hydrogen outlet 15 corresponds to the second hydrogen outlet 25 , the first air inlet 12 corresponds to the second air inlet 22 , the first air outlet 13 corresponds to the second air outlet 23 , the first coolant inlet 16 corresponds to the second coolant inlet 26 , and the first coolant outlet 17 corresponds to the second coolant outlet 27 .

[0042] Furthermore, the first air inlets 12 and the first air outlets 13 are arranged in an array at intervals; and the second air inlets 22 and the second air outlets 23 are arranged in an array at intervals.

[0043] Preferably, the plane of the cathode plate 1 may also be configured as a second ridge structure matching the ridge structure 28 of the anode plate 2 , which may cooperate with the ridge structure 28 of the anode plate 2 to form a cooling liquid flow channel 29 .

[0044] In one embodiment of the present invention, the air return flow channel includes several flow channel groups 111, each of which includes three branch flow channels 1111, each of which has a U-shaped structure. Furthermore, the width of the branch flow channels 1111 can be adjusted or the number of branch flow channels 1111 can be reduced based on the actual power requirements of the fuel cell stack, thereby further optimizing the humidification effect. The U-shaped structure of the branch flow channels 1111 can effectively reduce the flow resistance of the flow channel, widening the design length of the fuel cell stack.

[0045] Furthermore, one first air inlet 12 and one first air outlet 13 correspond to one flow channel group 111 , and the number of first air inlets 12 , first air outlets 13 and flow channel groups 111 can be specifically set according to actual conditions.

[0046] Furthermore, the inlet and outlet of the branch flow channel 1111 are respectively connected to the first air inlet 12 and the first air outlet 13 .

[0047] In one embodiment of the present invention, a hydrogen inlet distribution area 212 and a hydrogen outlet distribution area 213 are provided on one side of the hydrogen flow channel 21, the second hydrogen inlet 24 is connected to the hydrogen flow channel 21 through the hydrogen inlet distribution area 212, and the second hydrogen outlet 25 is connected to the hydrogen flow channel 21 through the hydrogen outlet distribution area 213.

[0048] In this embodiment, the hydrogen flow channel 21 includes several hydrogen branch channels 211. The inlet of the hydrogen branch channel 211 is connected to the second hydrogen inlet 24 through the hydrogen inlet distribution area 212. After the hydrogen enters the hydrogen inlet distribution area 212 through the hydrogen inlet, it is distributed into the inlet of each hydrogen branch channel 211; the outlet of the hydrogen branch channel 211 is connected to the second hydrogen outlet 25 through the hydrogen outlet distribution area 213. After passing through each hydrogen branch channel 211, the hydrogen enters the hydrogen outlet distribution area 213 from the outlet of the hydrogen branch channel 211, and is then distributed into the second hydrogen outlet 25. The setting of the hydrogen inlet distribution area 212 and the hydrogen outlet distribution area 213 is conducive to the collection and distribution of the gas.

[0049] Furthermore, the hydrogen inlet distribution area 212 and the hydrogen outlet distribution area 213 are symmetrically arranged.

[0050] In one embodiment of the present invention, the first coolant inlet 16 and the first coolant outlet 17 are located between the first hydrogen inlet 14 and the first hydrogen outlet 15, and are symmetrically arranged between the first coolant inlet 16 and the first hydrogen inlet 14 and the first coolant outlet 17 and the first hydrogen outlet 15; the second coolant inlet 26 and the second coolant outlet 27 are located between the second hydrogen inlet 24 and the second hydrogen outlet 25, and are symmetrically arranged between the second coolant inlet 26 and the second hydrogen inlet 24 and the second coolant outlet 27 and the second hydrogen outlet 25.

[0051] In one embodiment of the present invention, the hydrogen flow channel 21 has an n-type structure, and the coolant flow channel 29 has a U-type structure. The S-type flow channel in the prior art can also use backflow to humidify the air inlet gas, but the S-type flow channel requires a 360-degree angle, which increases the flow resistance and also reduces the design length of the fuel cell stack. Designing the hydrogen flow channel 21 as an n-type structure and the coolant flow channel 29 as a U-type structure allows the gas or liquid to reflux only once, effectively reducing the flow resistance of the flow channel and widening the design length of the fuel cell stack.

[0052] Furthermore, the cathode plate 1 and the anode plate 2 are made of graphite. Graphite cathode plates 1 and anode plates 2 have the advantages of small size, light weight, excellent performance, stable operation, low cost, high efficiency, long life, and corrosion resistance, and have low contact resistance with the MEA.

[0053] The working principle of this cathode reflow self-humidification liquid-cooled bipolar plate:

[0054] First, self-humidification refers to the use of water generated during operation to humidify the gas newly introduced into the stack. A portion of the water generated during operation needs to be retained for self-humidification. Therefore, the dry air at the air duct inlet 112 needs to transfer moisture to the high-humidity air at the air duct outlet 113. Therefore, the air duct inlet 112 needs to communicate with the air duct outlet 113. The air duct surface of the cathode plate 1 is connected to the gas diffusion layer, which acts as both an electron conductor and a moisture transferor, transferring moisture from the air duct outlet 113 to the air duct inlet 112. During operation, the dry air from the first air inlet 12 enters the first flow channel group 111 and is divided into three branch flow channels 1111. The air flows through and carries the moisture generated by the working reaction of the fuel cell stack and the internal energy released by the reaction to humidify and heat the gas at the rear end of the air flow channel 11. The moisture penetrates the gas diffusion layer and reaches the inlet of the air flow channel 11. The dry air will carry a certain amount of moisture and flow to the air flow channel outlet 113. The above steps are repeated between the next first air inlet 12, the first air outlet 13 and the flow channel group 111, and so on.

[0055] Secondly, in addition to permeating the air flow channel outlet 113 of the first flow channel group 111 through the gas diffusion layer to the air flow channel inlet 112, the moisture also permeates through the gas diffusion layer to the air flow channel inlet 112 of the next flow channel group 111. Similarly, the air flow channel inlet 112 of the next flow channel group 111 can receive both reflux humidification from the previous flow channel group 111 and reflux humidification between the flow channel groups 111 to which it belongs, resulting in a better self-humidification effect than the previous flow channel group 111. Therefore, the width of the branch flow channel 1111 can be adjusted or the number of branch flow channels 1111 can be reduced according to the actual power requirements of the fuel cell stack to further optimize the uniformity of humidification.

[0056] In summary, under the requirements of the stack such as the smallest possible flow resistance, high power-to-volume ratio, and high power-to-mass ratio, the cathode reflux of this liquid-cooled bipolar plate with self-humidification can effectively balance the temperature and humidity transfer between the flow channels inside the fuel cell, so that the cathode of the stack can achieve the effect of self-humidification.

[0057] The inlet and outlet of the above-mentioned flow channel refer to the inlet and outlet of the flow channel or the flow-through area, and are not narrowly defined through-hole openings.

[0058] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A liquid-cooled bipolar plate with cathode reflow self-humidification, characterized in that: include: A cathode plate (1), wherein one side of the cathode plate (1) is configured to form an air flow channel (11), and the other side is configured to be flat, a plurality of vertically arranged first air inlets (12) and first air outlets (13) are provided on one side of the air flow channel (11), the first air inlet (12) is connected to the air flow channel inlet, and the first air outlet (13) is connected to the air flow channel outlet to form an air return flow channel, and the cathode plate (1) is provided with a first hydrogen inlet (14), a first coolant inlet (16), a first coolant outlet (17) and a first hydrogen outlet (15) arranged in sequence at one end away from the first air inlet (12) and the first air outlet (13); An anode plate (2), wherein one side of the anode plate (2) is configured to form a hydrogen flow channel (21), and the other side is configured to form a ridge structure (28), one side of the hydrogen flow channel (21) is provided with a plurality of second air inlets (22) and second air outlets (23), and an end of the anode plate (2) away from the second air inlet (22) and the second air outlet (23) is provided with a second hydrogen inlet (24), a second coolant inlet (26), a second coolant outlet (27), and a second hydrogen outlet (25) arranged in sequence; The first air inlet (12) and the first air outlet (13) are respectively connected to the stack air inlet and the stack air outlet, so that the stack air inlet and the stack air outlet are interconnected; The cathode plate (1) and the anode plate (2) are connected in a coordinated manner so that the plane and the ridge structure (28) abut against each other to form a coolant flow channel (29); the first coolant inlet (16) and the first coolant outlet (17) are connected through the coolant flow channel (29).

2. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: The first air inlets (12) and the first air outlets (13) are arranged in an array at intervals; and the second air inlets (22) and the second air outlets (23) are arranged in an array at intervals.

3. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: The first hydrogen inlet (14) corresponds to the second hydrogen inlet (24), the first hydrogen outlet (15) corresponds to the second hydrogen outlet (25), the first air inlet (12) corresponds to the second air inlet (22), the first air outlet (13) corresponds to the second air outlet (23), the first coolant inlet (16) corresponds to the second coolant inlet (26), and the first coolant outlet (17) corresponds to the second coolant outlet (27).

4. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: The air return flow channel comprises a plurality of flow channel groups (111), one of the flow channel groups (111) comprises three branch flow channels (1111), and the branch flow channels (1111) are in a U-shaped structure.

5. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 4, characterized in that: The inlet and outlet of the branch flow channel (1111) are respectively connected to the first air inlet (12) and the first air outlet (13).

6. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: A hydrogen inlet distribution area (212) and a hydrogen outlet distribution area (213) are provided on one side of the hydrogen flow channel (21); the second hydrogen inlet (24) is connected to the hydrogen flow channel (21) through the hydrogen inlet distribution area (212); and the second hydrogen outlet (25) is connected to the hydrogen flow channel (21) through the hydrogen outlet distribution area (213).

7. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 6, characterized in that: The hydrogen inlet distribution area (212) and the hydrogen outlet distribution area (213) are symmetrically arranged.

8. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: The first coolant inlet (16) and the first coolant outlet (17) are located between the first hydrogen inlet (14) and the first hydrogen outlet (15), and the first coolant inlet (16) and the first hydrogen inlet (14) are symmetrically arranged between the first coolant outlet (17) and the first hydrogen outlet (15); the second coolant inlet (26) and the second coolant outlet (27) are located between the second hydrogen inlet (24) and the second hydrogen outlet (25), and the second coolant inlet (26) and the second hydrogen inlet (24) are symmetrically arranged between the second coolant outlet (27) and the second hydrogen outlet (25).

9. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: The hydrogen flow channel (21) is an n-type structure, and the coolant flow channel (29) is a U-type structure.

10. The cathode reflow self-humidifying liquid-cooled bipolar plate according to claim 1, characterized in that: The cathode plate (1) and the anode plate (2) are made of graphite.

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