Fluid system of fuel cell and fuel cell stack
By using valve devices and controllers in the fluid system of the fuel cell, alternating changes in the flow direction of oxygen and hydrogen are solved, the problem of insufficient durability and stability of the fuel cell is achieved, and the balance of the temperature, pressure and current density of the flow channel group is achieved, and the overall performance of the fuel cell is improved.
Patent Information
- Application Number
- CN202421868611.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-08-02
AI Technical Summary
The durability and stability of existing fuel cells are poor, and they need to improve their durability and stability in use.
By introducing valve devices and controllers into the fluid system of the fuel cell, the flow direction of oxygen and hydrogen in the bipolar plate flow channel group is controlled, and the alternating change of flow direction is achieved, thereby maintaining the balance of temperature, pressure and current density in the flow channel group.
Through alternating flow direction adjustment, the temperature, pressure and current density of the bipolar plate flow channel group can be maintained, and the durability and stability of the fuel cell can be improved.
Smart Images
Figure CN223006792U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of fuel cells, and particularly relates to a fluid system of a fuel cell and a fuel cell stack. Background Art
[0002] A fuel cell is an energy conversion device that directly converts the chemical energy stored in fuels and oxidants into electrical energy according to the principle of electrochemistry. Since a fuel cell converts the Gibbs free energy part of the chemical energy of the fuel into electrical energy through an electrochemical reaction and is not restricted by the Carnot cycle effect, the conversion efficiency is relatively high. In addition, a fuel cell uses oxygen and fuel as raw materials, and there are no mechanical transmission components, so there is no noise pollution and extremely few harmful gases are emitted. Energy and the environment have become the focus issues for the survival of human society. In the past 20 years, fuel cells have shown broad application prospects in civil and military fields such as transportation, portable power sources, stationary power plants, aerospace, and underwater submersibles.
[0003] However, the durability and stability of current fuel cells are poor. Therefore, how to improve the durability and stability of fuel cells is an urgent problem to be solved. Summary of the Utility Model
[0004] In view of the problems existing in the above-mentioned prior art, a fluid system of a fuel cell and a fuel cell stack are proposed. By using this fluid system of a fuel cell and a fuel cell stack, the durability and stability of the fuel cell can be improved.
[0005] This application provides the following solutions.
[0006] In a first aspect, this application provides a fluid system of a fuel cell. The fluid system of the fuel cell includes a valve device. The bipolar plate of the fuel cell includes a flow channel group for flowing oxygen and hydrogen.
[0007] The first end of the flow channel group is connected to the first interface of the valve device, and the second end of the flow channel group is connected to the second interface of the valve device. The third interface of the valve device is used for inputting oxygen and hydrogen, and the fourth interface of the valve device is used for outputting the output fluid.
[0008] The valve device includes a first state and a second state. When the valve device is in the first state, the first interface is communicated with the third interface, and the second interface is communicated with the fourth interface.
[0009] When the valve device is in the second state, the first interface is communicated with the fourth interface, and the second interface is communicated with the third interface.
[0010] As a possible implementation manner, the fluid system of the fuel cell includes a controller.
[0011] The controller is used to control the valve device to switch between a first state and a second state.
[0012] As a possible implementation, the flow channel group is used for flowing oxygen, hydrogen, and coolant;
[0013] The third interface of the valve device is used for inputting oxygen, hydrogen, and coolant.
[0014] As a possible implementation, the valve device includes a first valve, a second valve, a third valve, and a fourth valve;
[0015] The first end of the first valve is used for inputting oxygen, hydrogen, and coolant, and the second end of the first valve is respectively connected to the first end of the flow channel group and the first end of the third valve;
[0016] The first end of the second valve is used for inputting oxygen, hydrogen, and coolant, and the second end of the second valve is respectively connected to the second end of the flow channel group and the first end of the fourth valve;
[0017] The second end of the third valve is used for outputting the output fluid, and the second end of the fourth valve is used for outputting the output fluid.
[0018] As a possible implementation, when the valve device is in the first state, the first valve and the fourth valve are open, and the third valve and the second valve are closed;
[0019] When the valve device is in the second state, the first valve and the fourth valve are closed, and the third valve and the second valve are open.
[0020] As a possible implementation, it further includes a power detection device;
[0021] The power detection device is connected to the controller of the valve device;
[0022] The power detection device is used to detect the power of the fuel cell;
[0023] The controller is used to control the valve device to switch from the first state to the second state after the power of the fuel cell starts to decay.
[0024] As a possible implementation, it further includes a timing unit;
[0025] The timing unit is connected to the controller of the valve device;
[0026] The timing unit is used to calculate the cumulative operating duration of the fuel cell;
[0027] The controller is used to control the valve device to switch from the first state to the second state after the cumulative operating duration of the fuel cell is greater than the preset duration.
[0028] As a possible implementation, the controller is configured to control the valve device to switch from the first state to the second state after receiving a control signal sent by an operator.
[0029] As a possible implementation, the fuel cell includes a proton exchange membrane fuel cell.
[0030] In a second aspect, the present application provides a fuel cell stack, which includes the above-mentioned fluid system, end plates, insulating plates, current collector plates, bipolar plates, and membrane electrode assemblies; two insulating plates are arranged between two end plates, two current collector plates are arranged between the two insulating plates, and a plurality of bipolar plates and a plurality of membrane electrode assemblies are alternately arranged between the two current collector plates.
[0031] For the fluid system of the fuel cell provided by the embodiments of the present application, by controlling the valve device to switch between the first state and the second state, the flow directions of oxygen and hydrogen in the flow channel group of the bipolar plate can be alternately changed. Since the temperature, pressure, and current density in the flow channel group change gradually along the flow channel, the present application enables the flow directions of oxygen and hydrogen in the flow channel group of the bipolar plate to be alternately changed, so that the temperature of the flow channel group of the bipolar plate, especially the temperature, pressure, and current density at the inlet or outlet of the flow channel, can be kept relatively balanced, thereby improving the durability and stability of the fuel cell.
[0032] Other advantages of the present application will be explained in more detail in conjunction with the following description and drawings.
[0033] It should be understood that the above description is only an overview of the technical solution of the present application, so as to understand the technical means of the present application more clearly, and thus it can be implemented according to the content of the specification. In order to make the above and other purposes, features, and advantages of the present application more obvious and understandable, the following specifically illustrates the specific implementation manners of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] By reading the following detailed description of the exemplary embodiments, those of ordinary skill in the art will understand the advantages and benefits described herein, as well as other advantages and benefits. The drawings are only for the purpose of illustrating the exemplary embodiments and are not considered to be a limitation of the present application. In the drawings:
[0035] Figure 1 It is a schematic diagram of a fluid system of a fuel cell provided by an embodiment of the present application;
[0036] Figure 2 It is a schematic diagram of another fluid system of a fuel cell provided by an embodiment of the present application;
[0037] Figure 3 It is a schematic diagram of a fluid system of a fuel cell provided by an embodiment of the present application;
[0038] Figure 4 A schematic diagram of a fuel cell stack provided by an embodiment of the present application.
[0039] In the drawings, the same or corresponding reference numerals indicate the same or corresponding parts.
[0040] Add description of reference numerals Detailed implementation manners
[0041] The exemplary embodiments of the present application will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be completely conveyed to those skilled in the art.
[0042] In the description of the embodiments of the present application, it should be understood that terms such as "including" or "having" are intended to indicate the presence of the disclosed features, numbers, steps, actions, components, parts, or combinations thereof in the present specification, and do not exclude the possibility of the presence of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.
[0043] Unless otherwise specified, " / " means "or". For example, A / B can mean A or B; "and / or" herein is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone.
[0044] Terms such as "first", "second", etc. are only used for convenience of description to distinguish the same or similar technical features, and cannot be understood as indicating or implying the relative importance or quantity of these technical features. Thus, the features defined by "first", "second", etc. can explicitly or implicitly include one or more of these features. In the description of the embodiments of the present application, unless otherwise specified, the meaning of the term "plurality" is two or more than two. Additionally, it should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.
[0045] The applicant has found that both the temperature and pressure vary along the flow channels in a fuel cell. For example, due to the rising temperature of the coolant and the continuous progress of the reaction, the temperature in the flow channels increases along the flow channels. Due to the progress of the reaction, the pressure in the flow channels decreases along the flow channels. Moreover, the current density of the reaction in the fuel cell is also related to the temperature and pressure in the flow channels. Therefore, the current density of the reaction in the fuel cell also varies along the flow channels. As a result, the temperature, pressure, and current density on the bipolar plate of the fuel cell are all distributed along the flow channels, leading to uneven distribution of stability, pressure, and current density on the bipolar plate, thereby making the durability and stability of the fuel cell poor.
[0046] Therefore, the present application provides a fluid system for a fuel cell, which can change the flow directions of oxygen and hydrogen in the flow channel group of the bipolar plate, so that the temperature, pressure, and current density in the flow channel group of the bipolar plate are kept relatively balanced, thereby improving the durability and stability of the fuel cell.
[0047] The present application will be described in detail below with reference to the drawings and in conjunction with embodiments.
[0048] See Figure 1 , which is a schematic diagram of a fluid system for a fuel cell provided by an embodiment of the present application.
[0049] As Figure 1 shown, the fluid system for a fuel cell provided by an embodiment of the present application includes: a valve device 100 and a controller 200.
[0050] The bipolar plate 300 of the fuel cell includes a flow channel group for flowing oxygen and hydrogen.
[0051] The first end 31 of the flow channel group is connected to the first interface 11 of the valve device 100, the second end 32 of the flow channel group is connected to the second interface 12 of the valve device 100, the third interface 13 of the valve device 100 is used for inputting oxygen and hydrogen, and the fourth interface 14 of the valve device 100 is used for outputting the output fluid.
[0052] The controller is used to control the valve device 100 to switch between a first state and a second state; when the valve device 100 is in the first state, the first interface 11 is communicated with the third interface 13, and the second interface 12 is communicated with the fourth interface 14; when the valve device 100 is in the second state, the first interface 11 is communicated with the fourth interface 14, and the second interface 12 is communicated with the third interface 13.
[0053] It should be noted that the fuel cell in this application can be a Proton Exchange Membrane Fuel Cell (PEM FC). The oxygen in this application can refer to pure oxygen or a gas containing oxygen, such as air, etc., and the embodiments of this application do not make any limitations in this regard. The output fluid in the embodiments of this application can include the gas remaining after the reaction of oxygen and the gas remaining after the reaction of hydrogen, and the embodiments of this application do not make any limitations in this regard. When the fuel cell is operating, if the valve device switches its state, for example, from the first state to the second state, it will affect the normal operation of the fuel cell, easily cause damage to the fuel cell, or lead to safety accidents. Therefore, the controller in the embodiments of this application is used to control the valve device to switch from the first state to the second state or from the second state to the first state when the fuel cell stops operating, and the embodiments of this application do not make any limitations in this regard.
[0054] In the fluid system of the fuel cell provided by the embodiments of this application, by controlling the valve device to switch between the first state and the second state, the flow directions of oxygen and hydrogen in the flow channel group of the bipolar plate can be alternately changed. Since the temperature, pressure, and current density in the flow channel group gradually change along the flow channel, making the flow directions of oxygen and hydrogen in the flow channel group of the bipolar plate alternately change in this application can keep the temperature of the flow channel group of the bipolar plate, especially the temperature, pressure, and current density at the inlet or outlet of the flow channel, relatively balanced. For example, when oxygen and hydrogen flow into the flow channel group from the first end, the temperature at the first end of the flow channel group is lower and the temperature at the second end is higher; when oxygen and hydrogen flow into the flow channel group from the second end, the temperature at the second end of the flow channel group is lower and the temperature at the first end is higher. In this way, by controlling the switching between the first state and the second state in this application, the temperature balance degree of the flow channel group can be improved, thereby improving the durability and stability of the fuel cell.
[0055] As a possible implementation manner, in order to make the temperature distribution in the fuel cell more balanced, this application can also change the flow direction of the coolant in the flow channels of the bipolar plate. As Figure 2 shown, the flow channel group in the embodiments of this application can be used to circulate oxygen, hydrogen, and coolant; the third interfaces of the valve device are respectively used to input oxygen, hydrogen, and coolant.
[0056] In the embodiments of this application, as Figure 3As shown, the valve device in the embodiment of the present application may include a first valve V1, a second valve V2, a third valve V3, and a fourth valve V4. The first end of the first valve V1 is respectively used for inputting oxygen, hydrogen, and coolant, and the second end of the first valve V1 is respectively connected to the first end of the flow channel group and the first end of the third valve V3; the first end of the second valve V2 is respectively used for inputting oxygen, hydrogen, and coolant, and the second end of the second valve V2 is respectively connected to the second end of the flow channel group and the first end of the fourth valve V4; the second end of the third valve V3 is used for outputting the output fluid, and the second end of the fourth valve V4 is used for outputting the output fluid.
[0057] In the embodiment of the present application, when the valve device is in the first state, the first valve V1 and the fourth valve V4 are opened, and the third valve V3 and the second valve V2 are closed. At this time, the first interface 11 is communicated with the third interface 13, the second interface 12 is communicated with the fourth interface 14, and the input reaction gas (including oxygen and hydrogen) and coolant flow in from the first end 31 of the bipolar plate flow channel group and flow out from the second end 32 of the bipolar plate flow channel group. When the valve device is in the second state, the first valve V1 and the fourth valve V4 are closed, and the third valve V3 and the second valve V2 are opened. At this time, the first interface 11 is communicated with the fourth interface 14, the second interface 12 is communicated with the third interface 13, and the input reaction gas (including oxygen and hydrogen) and coolant flow in from the second end 32 of the bipolar plate flow channel group and flow out from the first end 31 of the bipolar plate flow channel group. Thus, the switching between the first state and the second state of the valve device in the present application realizes the change of the flow direction of oxygen and hydrogen in the flow channel group of the bipolar plate, so that the temperature, pressure, and current density in the flow channel group of the bipolar plate are kept relatively balanced, thereby improving the durability and stability of the fuel cell.
[0058] In some possible embodiments, the fluid system of the fuel cell further includes a power detection device. The power detection device is used to send an attenuation signal to the controller after detecting that the power of the fuel cell starts to decay. The controller is used to control the valve device to switch from the first state to the second state when the fuel cell stops running after receiving the attenuation signal. It should be noted that after the power detection device detects that the power of the fuel cell starts to decay, it indicates that the distribution uniformity of the temperature, pressure, and current density in the fuel cell may be relatively low, resulting in a locally low power in the fuel cell. Therefore, in the present application, after the controller receives the attenuation signal and when the fuel cell stops running, it controls the valve device to switch from the first state to the second state. After the valve device switches from the first state to the second state, the flow direction of the reaction gas and coolant in the bipolar plate flow channel group changes, which can improve the distribution uniformity of the temperature, pressure, and current density in the fuel cell to a certain extent and alleviate the power decay of the fuel cell.
[0059] In some possible embodiments, the fluid system of the fuel cell further includes a timing unit. The timing unit is configured to send a time signal to the controller after the cumulative operating duration of the fuel cell is greater than a preset duration. The controller is configured to control the valve device to switch from a first state to a second state when the fuel cell stops operating after receiving an attenuation signal. It should be noted that after the cumulative operating duration of the fuel cell is greater than the preset duration, it indicates that the uniformity of the temperature, pressure, and current density distribution in the fuel cell may be relatively low at this time. To avoid power attenuation of the fuel cell, the controller in this application controls the valve device to switch from a first state to a second state when the fuel cell stops operating after receiving an attenuation signal. After the valve device switches from the first state to the second state, the flow directions of the reaction gas and the coolant in the bipolar plate flow channel group change, which can, to a certain extent, improve the uniformity of the temperature, pressure, and current density distribution in the fuel cell and avoid power attenuation of the fuel cell.
[0060] In some possible embodiments, the state switching of the valve device can be controlled by an operator. The controller in the fluid system of the fuel cell is configured to control the valve device to switch from a first state to a second state when the fuel cell stops operating after receiving a control signal sent by the operator.
[0061] In summary, for the fluid system of the fuel cell provided in the embodiments of the present application, by controlling the valve device to switch between a first state and a second state, the flow directions of oxygen, hydrogen, and the coolant in the flow channel group of the bipolar plate can be changed. That is, oxygen, hydrogen, and the coolant can be input into the flow channel group from the first end of the bipolar plate flow channel group, or can be input into the flow channel group from the second end of the bipolar plate flow channel group. Since the temperature, pressure, and current density in the flow channel group gradually change along with the flow channel, the present application enables the flow directions of oxygen, hydrogen, and the coolant in the flow channel group of the bipolar plate to alternate, which can keep the temperature of the flow channel group of the bipolar plate, especially the temperature, pressure, and current density at the inlet or outlet of the flow channel, relatively balanced, thereby improving the durability and stability of the fuel cell.
[0062] Based on the fluid system of the fuel cell provided in the above embodiments, the present application also provides a fuel cell stack.
[0063] As Figure 4 shown, the fuel cell stack provided in the embodiments of the present application includes the fluid system in the above embodiments (not shown in the figure), end plates 301, insulating plates 302, current collector plates 303, bipolar plates 300, and membrane electrodes 305.
[0064] Among them, two insulating plates 302 are arranged between two end plates 301, two current collector plates 303 are arranged between two insulating plates 302, and multiple bipolar plates 300 and multiple membrane electrodes 305 are alternately arranged between two current collector plates 303.
[0065] It should be noted that the fuel cell stack in the embodiments of the present application includes various components that implement the fluid system of the fuel cell in the foregoing embodiments and achieve the same effects and functions, which will not be elaborated here.
[0066] In the description of this specification, the descriptions made with reference to terms such as "some possible implementation manners", "some implementation manners", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the implementation manner or example are included in at least one implementation manner or example of the present application, and the above terms do not necessarily refer to the same implementation manner or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more implementation manners or examples. In addition, without contradiction, those skilled in the art can combine and combine the different implementation manners or examples described in this specification and the features of different implementation manners or examples.
[0067] Although the spirit and principle of the present application have been described above with reference to several specific implementation manners, it should be understood that the present application is not limited to the disclosed specific implementation manners, and the division of each aspect does not mean that the features in these aspects cannot be combined. The present application aims to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Claims
1. A fluid system of a fuel cell, characterized in that: The fluid system of the fuel cell includes a valve device, and the bipolar plate of the fuel cell includes a flow channel group, and the flow channel group is used to circulate oxygen and hydrogen; The first end of the flow channel group is connected to the first interface of the valve device, the second end of the flow channel group is connected to the second interface of the valve device, the third interface of the valve device is used to input oxygen and hydrogen, and the fourth interface of the valve device is used to output the output fluid; The valve device includes a first state and a second state. When the valve device is in the first state, the first interface is connected to the third interface, and the second interface is connected to the fourth interface. When the valve device is in the second state, the first interface is connected to the fourth interface, and the second interface is connected to the third interface.
2. The fluid system of the fuel cell according to claim 1, characterized in that: The fluid system of the fuel cell includes a controller; The controller is used to control the valve device to switch between the first state and the second state.
3. The fluid system of the fuel cell according to claim 1, characterized in that: The flow channel group is used for circulating oxygen, hydrogen and coolant; The third interface of the valve device is used for inputting oxygen, hydrogen and coolant.
4. The fluid system of the fuel cell according to claim 3, characterized in that: The valve device comprises a first valve, a second valve, a third valve and a fourth valve; The first end of the first valve is used to input oxygen, hydrogen and coolant, and the second end of the first valve is respectively connected to the first end of the flow channel group and the first end of the third valve; The first end of the second valve is used to input oxygen, hydrogen and coolant, and the second end of the second valve is respectively connected to the second end of the flow channel group and the first end of the fourth valve; The second end of the third valve is used to output the output fluid, and the second end of the fourth valve is used to output the output fluid.
5. The fluid system of the fuel cell according to claim 4, characterized in that: When the valve device is in a first state, the first valve and the fourth valve are opened, and the third valve and the second valve are closed; When the valve device is in the second state, the first valve and the fourth valve are closed, and the third valve and the second valve are opened.
6. The fluid system of the fuel cell according to claim 2, characterized in that: Also included is a power detection device; The power detection device is connected to the controller of the valve device; The power detection device is used to detect the power of the fuel cell; The controller is used for controlling the valve device to switch from the first state to the second state after the power of the fuel cell starts to decay.
7. The fluid system of the fuel cell according to claim 2, characterized in that: Also includes a timing unit; The timing unit is connected to the controller of the valve device; The timing unit is used to calculate the cumulative operating time of the fuel cell; The controller is used for controlling the valve device to switch from the first state to the second state after the accumulated operation time of the fuel cell is greater than a preset time.
8. The fluid system of the fuel cell according to claim 2, characterized in that: The controller is used to control the valve device to switch from the first state to the second state after receiving a control signal sent by an operator.
9. The fluid system of a fuel cell according to any one of claims 1 to 8, characterized in that: The fuel cell comprises a proton exchange membrane fuel cell.
10. A fuel cell stack, characterized in that: The fuel cell stack comprises the fluid system according to any one of claims 1 to 9, an end plate, an insulating plate, a current collecting plate, a bipolar plate and a membrane electrode; Two insulating plates are arranged between the two end plates, two current collecting plates are arranged between the two insulating plates, and a plurality of bipolar plates and a plurality of membrane electrodes are arranged alternately between the two current collecting plates.