A monopolar plate and a bipolar plate including a distribution channel structure

Abstract

The utility model provides a monopolar plate and a bipolar plate including a distribution channel structure, belonging to the field of fuel cell technology, specifically including a fluid inlet and outlet, a fluid reaction zone and at least one shunt reaction zone, the shunt reaction zone includes a shunt unit and a fluid reaction zone, and the shunt unit is provided with a primary shunt ridge, a secondary shunt ridge and a diffusion zone, so that the oxygen consumption in each flow channel is approximately equal. The utility model solves the problem of uneven distribution of media in each flow channel in a fuel cell bipolar plate, improves the overall working efficiency of the fuel cell, reduces the consumption of raw materials, and reduces costs.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and in particular to a monopolar plate and a bipolar plate comprising a distribution channel structure. Background Art

[0002] A hydrogen fuel cell is a device that uses hydrogen and oxygen as raw materials to generate electricity and heat through a series of electrochemical reactions.

[0003] Inside the fuel cell stack, the bipolar plate and membrane electrode separate three different media: hydrogen, oxygen and coolant. The space between the bipolar plate and the membrane electrode is the flow channel for hydrogen and oxygen. The hydrogen and oxygen transported from the header enter the bipolar plate flow channel and react with the membrane electrode in the flow channel. The gas flow channels on the bipolar plate are generally of equal width, and theoretically the gas is evenly distributed. In the actual operation of the fuel cell, due to uneven gas distribution, the amount of gas in each bipolar plate flow channel is different. Along the gas flow direction, as the reaction proceeds, in the hydrogen flow channel, near the flow channel outlet, the hydrogen surplus of each flow channel varies greatly. In the oxygen flow channel, the oxygen surplus and the amount of water generated near the flow channel outlet vary greatly. This causes inconsistent reaction efficiencies in different reaction areas, with excess media in some areas and insufficient media in some areas, which ultimately leads to a decrease in overall efficiency. At the same time, due to uneven heat generation, the life and sealing of the membrane electrode are affected.

[0004] At present, the conventional bipolar plate flow channel design only considers gas diversion in the inlet diversion area. In order to ensure the gas supply as much as possible, the gas supply is increased by increasing the metering ratio on the basis of the theoretical gas demand. This method not only increases the gas consumption, but also increases the power of gas delivery equipment (such as hydrogen pumps, air compressors, blowers, etc.), which ultimately leads to an increase in cost. The problem of uneven gas distribution will also cause oversaturation in the flow channel with excessive gas supply and lack of material in the flow channel with insufficient gas supply. The different degrees of reaction in these two types of flow channels lead to different heat generated by the reaction. The resulting temperature difference stress will cause corresponding sealing problems and will also have a great impact on the life of the membrane electrode. In the flow channel with insufficient reaction material, the electrochemical reaction is not sufficient, resulting in a corresponding loss of effective reaction area, which ultimately leads to a decrease in the efficiency of the entire fuel cell and affects performance. Utility Model Content

[0005] Therefore, in order to overcome the above-mentioned shortcomings of the prior art, the utility model provides a monopolar plate and a bipolar plate including a distribution channel structure to solve the problem of uneven gas distribution in each channel of the monopolar plate and the bipolar plate of the fuel cell.

[0006] In order to achieve the above-mentioned object, the utility model provides the following technical solution: a monopolar plate including a distribution channel structure, characterized in that it includes:

[0007] The plate body has a fluid inlet and outlet and an active area, wherein the active area has a first fluid reaction area for accommodating a fluid flow channel and at least one split flow reaction area, wherein the split flow reaction area is provided with a split flow unit and a second fluid reaction area;

[0008] The flow splitting unit includes a primary flow splitting ridge and a diffusion zone, which are used to adjust the fluid distribution ratio in the fluid reaction zone of the flow splitting reaction zone.

[0009] Specifically, the primary flow dividing ridge is arc-shaped on the side facing the gas flow direction, and is triangular-shaped on the other side.

[0010] Specifically, the primary flow dividing ridge is located on the center line of the fluid flow channel.

[0011] Specifically, the width of the primary diverter ridge is 50% to 70% of the width of the fluid flow channel.

[0012] Specifically, the diversion unit further includes a secondary diversion ridge, and the secondary diversion ridge is a point-shaped diversion ridge.

[0013] Specifically, the secondary diverter ridge is located between the primary diverter ridge and the diffusion zone, and the spatial ratio of the primary diverter ridge, the secondary diverter ridge and the diffusion zone is 2:1:4.

[0014] Specifically, the transverse length ratio of the primary diverter ridge to the secondary diverter ridge is 3.5-5:1, and the longitudinal height ratio is 2-3:1.

[0015] Specifically, the width ratio between the fluid reaction zones of the first fluid reaction zone and a branch reaction zone is 0.85-1.15:1.

[0016] Specifically, the number of the split flow reaction zones is 2 to 5.

[0017] The present application also provides a bipolar plate, which is prepared using any of the monopolar plates described above.

[0018] Compared with the prior art, the advantages of the present application are: a flow diversion unit is provided, and the gas is distributed multiple times during the reaction process of the fluid reaction zone of the monopolar plate and the bipolar plate, thereby improving the distribution balance of the gas. The problem of uneven distribution of the medium in each flow channel in the monopolar plate and the bipolar plate is solved; through the diversion effect of the flow diversion zone, the oxygen consumption in each flow channel is approximately equal, which fully utilizes the effective area of ​​the electrochemical reaction and improves the efficiency of the fuel cell; the gas is evenly distributed, and the reaction degree in the flow channel is the same and the heat generated is the same, which prevents the corresponding sealing problem and improves the life of the membrane electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a monopolar plate or a bipolar plate including a distribution channel structure as described in the embodiments of the present application;

[0021] Figure 2 It is an enlarged view of the diversion unit described in the embodiment of the present application. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0023] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0024] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0025] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0026] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0027] The embodiment of the present application provides a monopolar plate and a bipolar plate including a distribution channel structure. The plate body comprises: a plate body having a fluid inlet and outlet and an active area, the active area having a first fluid reaction area accommodating a fluid flow channel and at least one split flow reaction area, the split flow reaction area being provided with a split flow unit and a second fluid reaction area;

[0028] The flow splitting unit includes a primary flow splitting ridge and a diffusion zone, which are used to adjust the fluid distribution ratio in the fluid reaction zone of the flow splitting reaction zone.

[0029] In one embodiment, the primary flow dividing ridge is arc-shaped on the side facing the gas flow direction, and is triangular-shaped on the other side.

[0030] In one embodiment, the primary flow-dividing ridge is located on the center line of the fluid flow channel.

[0031] In one embodiment, the width of the primary diverter ridge is 50% to 70% of the width of the fluid flow channel.

[0032] In one embodiment, the diversion unit further includes a secondary diversion ridge, and the secondary diversion ridge is a point-shaped diversion ridge.

[0033] In one embodiment, the secondary diverter ridge is located between the primary diverter ridge and the diffusion zone, and the spatial ratio of the primary diverter ridge, the secondary diverter ridge and the diffusion zone is 2:1:4.

[0034] In one embodiment, the transverse length ratio of the primary diverter ridge to the secondary diverter ridge is 3.5-5:1, and the longitudinal height ratio is 2-3:1.

[0035] In one embodiment, the width ratio between the fluid reaction zones of the first fluid reaction zone and a branch reaction zone is 0.85-1.15:1.

[0036] In one embodiment, the number of the split reaction zones is 2 to 5.

[0037] In one embodiment, a bipolar plate is provided, which is prepared using any of the monopolar plates described above.

[0038] Example 1

[0039] The plate body includes: a fluid inlet manifold, an inlet diversion area, a first fluid reaction area, a first diversion reaction area, an outlet confluence area, and a fluid outlet manifold. The first diversion reaction area includes: a diversion unit and a second fluid reaction area. The diversion unit includes: a primary diversion ridge and a diffusion area. The diversion unit is used to adjust the fluid arrangement ratio in the second fluid reaction area in the first diversion reaction area so that the fluid in the second fluid reaction area is evenly distributed. The primary diversion ridge is a water drop-shaped diversion ridge, which is arc-shaped on the side facing the gas flow and triangular on the other side. The primary diversion ridge is located on the center line of the flow channel of the first flow channel reaction area and the second flow channel reaction area, and the width is 50% to 70% of the flow channel width. The diversion unit in the first diversion reaction area also includes a secondary diversion ridge, which is a point-shaped diversion ridge and is arranged between the primary diversion ridge and the diffusion area of ​​the diversion unit. The lateral length ratio of the primary diversion ridge to the secondary diversion ridge is 3.5 to 5:1, and the longitudinal height ratio is 2 to 3:1. The width ratio of the first fluid reaction zone to the second fluid reaction zone is 0.85-1.15:1.

[0040] Example 2

[0041] In one embodiment, the fuel cell system stack output power is 7kw, and 50 single cells are stacked inside the stack. This embodiment takes the gas flow channel on the cathode side of one of the single cells as an example for explanation. Each bipolar plate has 21 grooves as gas flow channels and 20 ridges for dividing the gas flow channels. The active area of ​​the bipolar plate has a first fluid reaction zone and two split flow reaction zones.

[0042] like Figure 1 As shown, the multiple distribution channel structure includes a gas inlet manifold 1, an inlet branch flow area 2, a first fluid reaction area 3, a first branch flow reaction area, a second branch flow reaction area, an outlet confluence area 8, and a gas outlet manifold 9.

[0043] The first split flow reaction zone includes a first split flow unit 4 and a second fluid reaction zone 5 , and the second split flow reaction zone includes a second split flow unit 6 and a second fluid reaction zone 7 .

[0044] In one embodiment, the length ratios of the inlet diversion zone 2, the first fluid reaction zone 3, the first diversion unit 4, the second fluid reaction zone 5, the second diversion unit 6 and the second fluid reaction zone 7 are 5%:28%:3%:28%:3%:28%:5%.

[0045] Oxygen from the external pipeline of the stack enters the bipolar plate from the gas inlet header 1. After entering the bipolar plate, the oxygen first enters the inlet diversion area 2 for diversion. The inlet diversion area 2 is densely covered with point-shaped diversion ridges to divert the oxygen flow so that the oxygen flow entering the gas flow channel is as even as possible.

[0046] The diverted oxygen flows into the first fluid reaction zone 3 , where the oxygen undergoes an electrochemical reaction with the membrane electrode in contact with the first fluid reaction zone 3 , consuming the oxygen and generating water.

[0047] Oxygen continues to flow to the next fluid reaction zone. Since the oxygen flow rate flowing into the first fluid reaction zone 3 is not completely uniform and the reaction process is uneven, the oxygen consumption in the flow channel is different, and finally the oxygen flow rates in each flow channel of the first fluid reaction zone 3 are quite different. In order to optimize the oxygen non-uniformity at the end of the first fluid reaction zone 3, a first flow splitting unit 4 is provided, and the oxygen flowing out of the first fluid reaction zone 3 is split for the second time in the first flow splitting unit 4.

[0048] Among them, Figure 2 As shown, the first flow dividing unit 4 includes, in order according to the flow direction of oxygen: a primary flow dividing ridge 11 , a secondary flow dividing ridge 12 , and a diffusion area 13 .

[0049] The secondary flow dividing ridge 11 is 65% of the flow channel width. The transverse length ratio of the primary flow dividing ridge 11 and the secondary flow dividing ridge 12 is 4.5:1; the longitudinal height ratio of the primary flow dividing ridge 11 and the secondary flow dividing ridge 12 is 2.5:1.

[0050] The primary diverter ridge 11 is located on the center line of the flow channel of the first fluid reaction zone 3, a portion of the secondary diverter ridge 12 is located directly behind the primary diverter ridge 11, the distance between the primary diverter ridge 11 and the secondary diverter ridge 12 is 3 times the diameter of the point-shaped diverter ridge 12, and another portion of the secondary diverter ridge 12 is located at the equal division between the two primary diverter ridges 11, and is located on the same straight line as the portion of the secondary diverter ridge 12 located directly behind the primary diverter ridge 11.

[0051] In the first diversion unit 4 , oxygen is first affected by the primary diversion ridge 11 for preliminary diversion, and then continues to flow to the secondary diversion ridge 12 , where the oxygen is finely diverted, and the diverted oxygen is fully balanced in the diffusion zone 13 .

[0052] The fully balanced oxygen enters the second fluid reaction zone 5, where the oxygen undergoes an electrochemical reaction with the contacting membrane electrode, consumes the oxygen, and generates water.

[0053] Oxygen continues to flow to the next fluid reaction zone. Since the oxygen flow rate flowing into the second fluid reaction zone 5 is not completely uniform and the reaction process is uneven, the oxygen consumption in the flow channel is different, and finally the oxygen amount in each flow channel of the second fluid reaction zone 5 is quite different. In order to optimize the oxygen non-uniformity at the end of the second fluid reaction zone 5, a second flow splitting unit 6 is provided, and the gas flowing out of the second fluid reaction zone 5 is split for the third time in the second flow splitting unit 6.

[0054] Among them, Figure 2As shown, the second flow dividing unit 6 includes, in order according to the flow direction of oxygen: a primary flow dividing ridge 11 , a secondary flow dividing ridge 12 , and a diffusion area 13 .

[0055] The primary flow dividing ridge 11 is 65% of the flow channel width. The transverse length ratio of the primary flow dividing ridge 11 to the secondary flow dividing ridge 12 is 4.5:1; the longitudinal height ratio of the primary flow dividing ridge 11 to the secondary flow dividing ridge 12 is 2.5:1.

[0056] The primary diverter ridge 11 is located on the center line of the flow channel of the second fluid reaction zone 5, a portion of the secondary diverter ridge 12 is located directly behind the primary diverter ridge 11, the distance between the primary diverter ridge 11 and the secondary diverter ridge 12 is 3 times the diameter of the secondary diverter ridge 12, and another portion of the secondary diverter ridge 12 is located at the equal division between the two primary diverter ridges 11, and is located on the same straight line as the portion of the secondary diverter ridge 12 located directly behind the primary diverter ridge 11.

[0057] In the second diversion unit 6 , oxygen is first affected by the primary diversion ridge 11 for preliminary diversion, and then continues to flow to the secondary diversion ridge 12 , where the oxygen is finely diverted, and the diverted oxygen is fully balanced in the diffusion area 13 .

[0058] The fully balanced oxygen enters the second fluid reaction zone 7, where it undergoes an electrochemical reaction with the membrane electrode in contact with the second fluid reaction zone 7, consuming the oxygen and generating water.

[0059] Finally, all the oxygen in the second fluid reaction zone 7 enters the outlet confluence zone 8. After the oxygen refluxes in the outlet confluence zone 8, it flows into the gas outlet header 9 and flows out of the fuel cell stack.

[0060] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A monopolar plate comprising a distribution channel structure, characterized in that: include: The plate body has a fluid inlet and outlet and an active area, wherein the active area has a first fluid reaction area for accommodating a fluid flow channel and at least one split flow reaction area, wherein the split flow reaction area is provided with a split flow unit and a second fluid reaction area; The flow splitting unit includes a primary flow splitting ridge and a diffusion zone, which are used to adjust the fluid distribution ratio in the fluid reaction zone of the flow splitting reaction zone.

2. The monopolar plate according to claim 1, characterized in that: The primary flow dividing ridge is arc-shaped on the side facing the gas flow direction, and is triangular-shaped on the other side.

3. The monopolar plate according to claim 1, characterized in that: The primary flow dividing ridge is located on the center line of the fluid flow channel.

4. The monopolar plate according to claim 1, characterized in that: The width of the primary flow dividing ridge is 50% to 70% of the width of the fluid flow channel.

5. The monopolar plate according to claim 1, characterized in that: The diversion unit further includes a secondary diversion ridge, and the secondary diversion ridge is a point-shaped diversion ridge.

6. The monopolar plate according to claim 5, characterized in that: The secondary diverter ridge is located between the primary diverter ridge and the diffusion zone, and the spatial ratio of the primary diverter ridge, the secondary diverter ridge and the diffusion zone is 2:1:

4.

7. The monopolar plate according to claim 5, characterized in that: The transverse length ratio of the primary diverter ridge to the secondary diverter ridge is 3.5-5:1, and the longitudinal height ratio is 2-3:

1.

8. The monopolar plate according to claim 1, characterized in that: The width ratio between the first fluid reaction zone and the fluid reaction zone of a branch reaction zone is 0.85-1.15:

1.

9. The monopolar plate according to claim 1, characterized in that: The number of the split flow reaction zones is 2 to 5.

10. A bipolar plate, characterized in that: The bipolar plate is prepared using the monopolar plate as described in any one of claims 1 to 9.

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