Fuel cell stack and fuel cell

Abstract

The utility model relates to a fuel cell stack and a fuel cell, belongs to the field of fuel cell stack structures, and aims to solve the problem of low cell temperature caused by heat conduction to the outside and self temperature reduction of an outermost single cell during cold start of the fuel cell, and is characterized in that an end plate component comprises an end plate, a ferromagnetic support plate, a coil and a temperature measuring device; the ferromagnetic supporting plate is loaded in the end plate, a first plate part and a second plate part which are opposite to each other of the end plate are separated in the end plate, and the plate surface of the first plate part is in contact with the single battery on the outermost layer; the coil is arranged on the first plate part, and the ferromagnetic supporting plate is partially or completely located in a variable magnetic field range capable of being generated by the coil; the temperature measuring device is arranged on the second plate part and collects the temperature of the ferromagnetic supporting plate, and the effect is that different coils generate eddy currents of different sizes in the corresponding supporting plate areas, and end plate partition heating is achieved.

Description

Technical Field

[0001] The utility model belongs to the field of fuel cell stack structures, and in particular relates to a fuel cell stack and a fuel cell with an end plate heating function. Background Art

[0002] A fuel cell is a device that converts the chemical energy of reactants into electrical energy. It has the characteristics of high power generation efficiency, low environmental pollution, high specific energy, and high reliability. The fuel cell stack is composed of core components of the stack, such as end plates, current collectors, bipolar plates, and membrane electrodes, which are stacked one by one. On the outermost side of the stack are the gas end plate and the blind end plate, on the inner side of the end plate is the current collector, and on the inner side of the current collector are single cells composed of bipolar plates and membrane electrodes placed alternately. During the operation of the stack, coolant flows through the inside of each bipolar plate to control the temperature of the stack. During the low-temperature start-up of the fuel cell, the heated coolant flows into each single cell of the stack, quickly warming up the battery and realizing rapid start-up of the stack. However, the single cells close to the end plates on both sides have their own temperature lowered due to heat conduction to the outer current collector and end plates, and often have a single low during the startup process, that is, the voltage at the end of the stack is low during the cold start process, resulting in startup failure. Utility Model Content

[0003] In order to solve the problem of low temperature in a fuel cell due to heat conduction from the outermost single cell to the outside during cold start, the temperature of the single cell itself decreases, resulting in low temperature, according to some specific embodiments of the present invention, the fuel cell stack includes:

[0004] A plurality of stacked single cells;

[0005] An end plate component, which limits the stacked single cells and contacts the single cells stacked on the outermost layer;

[0006] Wherein, the end plate component includes an end plate, a ferromagnetic support plate, a coil and a temperature measuring device;

[0007] The ferromagnetic support plate is loaded inside the end plate, and separates two opposite first plate parts and second plate parts of the end plate inside the end plate, and the plate surface of the first plate part contacts the single battery of the outermost layer;

[0008] The coil is connected to an AC power supply to generate a variable magnetic field, the coil is arranged on the first plate portion, and part or all of the ferromagnetic support plate is within the variable magnetic field range that can be generated by the coil;

[0009] The temperature measuring device is arranged on the second plate portion to collect the temperature of the ferromagnetic support plate.

[0010] According to the fuel cell stack in some specific embodiments of the present invention, the end plate component includes an air port end plate and / or a blind end plate; the coil is arranged inside or on the surface of the first plate part, and the temperature measuring device is arranged inside or on the surface of the second plate part.

[0011] According to some specific embodiments of the present invention, the fuel cell stack further includes

[0012] A controller, the controller being connected to the temperature measuring device and transmitting the temperature of the ferromagnetic support plate collected by the temperature measuring device to the controller;

[0013] An AC power supply is connected to the controller, and the controller controls the coil to connect to or disconnect from the AC power supply.

[0014] According to the fuel cell stack in some specific embodiments of the present invention, the AC power supply is an AC power supply with variable amplitude and frequency, and the controller controls the amplitude and frequency of the AC power supply.

[0015] According to the fuel cell stack in some specific embodiments of the utility model, a plurality of the coils are distributed at intervals on the first plate portion, a plurality of the temperature measuring devices are distributed at intervals on the second plate portion, and each coil of the first plate portion is arranged in a one-to-one correspondence with each temperature measuring device of the second plate portion, wherein the heating area corresponding to any coil on the ferromagnetic support plate is the temperature collection area corresponding to the temperature measuring device corresponding to any coil on the ferromagnetic support plate.

[0016] According to some specific embodiments of the present invention, the fuel cell stack further includes

[0017] A controller, the controller being connected to the plurality of temperature measuring devices, and transmitting the temperatures of the plurality of positions of the ferromagnetic support plate collected by the plurality of temperature measuring devices to the controller;

[0018] A multi-channel AC power supply, wherein the controller is connected to the multi-channel AC power supply and controls one or more of the plurality of coils to be connected to or disconnected from the corresponding channel AC power supply.

[0019] According to the fuel cell stack in some specific embodiments of the present invention, the multi-channel AC power supply is an AC power supply with variable amplitude and frequency, and the controller controls the amplitude and frequency of the AC power supply of each channel.

[0020] According to the fuel cell stack in some specific embodiments of the present invention, the plurality of coils arranged on the first plate portion are arranged equidistantly, and the plurality of temperature measuring devices arranged on the second plate portion are arranged equidistantly.

[0021] According to the fuel cell stack in some specific embodiments of the present invention, the several equidistantly arranged coils of the first plate portion are arranged in more than two rows, and the several equidistantly arranged temperature measuring devices of the second plate portion are arranged in more than two rows.

[0022] In a second aspect, a fuel cell according to some specific embodiments of the present invention comprises the fuel cell stack described in any one of the first aspects.

[0023] Beneficial effects: The fuel cell stack with end plate heating function of the utility model has ferromagnetic support plates, coil matrices and temperature measurement matrices installed in the gas end plate and the blind end plate, respectively. Before the stack is cold-started, the controller starts the internal multi-channel AC power supply to power the coil matrices inside the two end plates. The alternating magnetic field generated by the coil matrix generates eddy currents of different sizes in different areas of the ferromagnetic support plate, thereby realizing zoned heating of the end plate. The multiple temperature sensors installed in the temperature measurement matrix can measure the temperature of different areas of the support plate. The heating area corresponds to the temperature measurement area one by one, and the results are fed back to the controller. The controller adjusts the alternating current of each channel to make each area of ​​the end plate evenly heated. The high-temperature end plate transfers heat to the outermost single cell of the stack by heat conduction. The risk of single low in the first single cell of the gas end and the blind end during the cold start process is reduced, which helps to solve the fuel cell end plate effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the basic structure of the battery stack.

[0025] Figure 2 Schematic diagram of the dispersed structure of the battery stack.

[0026] Figure 3 Schematic diagram of the controller placed outside the basic structure of the fuel cell stack.

[0027] Figure 4 Schematic diagram of the end plate component structure.

[0028] Figure 5 It is a schematic diagram of the first plate portion.

[0029] Figure 6 Schematic diagram of the second plate portion.

[0030] Figure 7 It is a schematic diagram that the coil and the temperature measuring device are separated by a ferromagnetic support plate.

[0031] in:

[0032] 10. Single battery

[0033] 20. end plate component, 21. end plate, 211. gas port end plate, 212. blind end plate, 22. ferromagnetic support plate, 23. coil, 24. temperature measuring device, 25. first plate part, 26. second plate part;

[0034] 30. Controller. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are further described below with reference to the accompanying drawings, and the advantages and features of the present invention will become clearer as the description proceeds.

[0036] Figure 1 Figure 1 is a schematic diagram of the basic structure of the battery stack. Figure 1 As shown, the basic structure of the battery stack includes a gas port end plate 211, a blind end plate 212 and a battery stack core. The battery stack core is composed of multiple single cells 10.

[0037] Figure 2 This is a schematic diagram of the dispersed structure of the battery stack. Figure 2 In order to show the positional relationship between the end plate and the single cell, the distance between the end plate 21 and the end single cell 10 (the outermost single cell of the stack), as well as the distance between adjacent single cells 10, is deliberately enlarged. There is basically no gap between the conventional end plate 21 and the end single cell 10, as well as the adjacent single cells 10. During the cold start of the fuel cell, the temperature of the end plate 21 is low due to the low external temperature. The two outermost single cells 10 in contact with the end plates 21 on both sides transfer heat to the end plates 21 by heat conduction, causing the temperature of the single cell 10 to decrease. Therefore, during cold start, the two single cells 10 at the end often freeze due to low temperature.

[0038] Figure 3 Schematic diagram of controller 30. Controller 30 is placed outside the basic structure of the battery stack. Controller 30 is connected to the coil matrix (a matrix composed of a plurality of coils 23 arranged) and the temperature measuring device matrix (a matrix composed of a plurality of temperature measuring devices 24) in the end plate component 20 through lines. Controller 30 is also connected to an AC power supply arranged outside. The AC power supply is a multi-channel high-frequency AC power supply, which can send alternating currents of different amplitudes and frequencies to different coils 23 synchronously or asynchronously. The controller 30 can use a single-chip microcomputer, a PLC or a processor.

[0039] Figure 4 Figure 1 is a schematic diagram of the end plate structure. Figure 4As shown, the end plate component 20 includes an end plate 21, a coil 23 matrix, a ferromagnetic support plate 22, and a temperature measuring device 24 matrix. The ferromagnetic support plate 22 is embedded in the end plate 21, such as being arranged in the middle position inside the end plate 21, and the plate surface of the ferromagnetic support plate 22 is parallel to the plate surface of the end 21. The ferromagnetic support plate 22 is equivalent to being inside the end plate 21, dividing the end plate 21 into two parts, namely the first plate portion 25 and the second plate portion 26, so that the coil 23 matrix and the temperature measuring device 24 matrix can be arranged on both sides of the ferromagnetic support plate 22. The first plate portion 25 where the coil 23 matrix is ​​located is in a direction away from the core, and the second plate portion 26 of the temperature measuring device 24 matrix is ​​in a direction close to the core, that is, the plate surface of the second plate portion 25 is in contact with the outermost single battery 10. In some schemes, the coil 23 matrix is ​​arranged inside the first plate 25, that is, inside the end plate 21, and is close to the plate surface of the first plate 25 inside. The temperature measuring device 24 matrix is ​​arranged inside the second plate 26, that is, inside the end plate 21, and is close to the plate surface of the second plate 26 inside. The coil 23 matrix is ​​a plurality of coils 23 arranged equidistantly in the horizontal and vertical directions. Any coil 23 in the coil 23 matrix has a temperature measuring device 24 in the corresponding temperature measuring device 24 matrix in space opposite to it, so that the heating position corresponding to a coil 23 on the ferromagnetic support plate 22 must correspond to (or be relative to) a temperature measuring position corresponding to a temperature measuring device 24. The heating position is the area on the ferromagnetic support plate 22 corresponding to the position of the coil 23 on the first plate 25, and the temperature measuring position is the position on the ferromagnetic support plate 22 corresponding to the position of the temperature measuring device on the second plate 26. The temperature measuring device can be implemented by a temperature sensor.

[0040] Among them, ferromagnetic materials are a type of solid materials with ferromagnetism, which can be magnetized under the action of an external magnetic field, and when the external magnetic field is removed, they can maintain a certain residual magnetism. The magnetism of ferromagnetic materials comes from the atomic magnetic moments inside them, which are usually randomly arranged in the absence of an external magnetic field, so they do not show magnetism macroscopically. However, when an external magnetic field acts, these magnetic moments tend to be arranged along the direction of the magnetic field, thereby generating magnetism. There are many types of ferromagnetic materials, including iron, nickel, cobalt and their alloys, as well as some special ceramic materials. Each material has its unique magnetic properties and is suitable for different application scenarios. The ferromagnetic support plate 22 in the utility model can be a support plate prepared by any of the above-mentioned existing ferromagnetic materials.

[0041] When an alternating current passes through the coil 23 matrix, that is, a multi-channel high-frequency AC power supply, the alternating current can generate a changing magnetic field, and each coil 23 corresponds to the area of ​​a portion of the ferromagnetic support plate 22. In this case, the ferromagnetic material is in a changing magnetic field, and the magnetic flux passing through the material changes. According to Faraday's law of electromagnetic induction, the changing magnetic flux generates an induced electromotive force in the conductor, driving the current to be generated. The closed loop formed by the current in the conductor is similar to a vortex in water, so it is called an eddy current. The generation and flow of eddy currents in ferromagnetic materials generate resistance losses, and the losses are dissipated in the form of heat, causing the ferromagnetic material to heat up. That is, the coil 23 is passed through an alternating current to generate eddy currents inside the ferromagnetic material support plate 22, so that the ferromagnetic material support plate 22 is heated, and then the temperature of the entire end plate 21 is increased. Each coil 23 corresponds to heating different areas of the ferromagnetic material support plate 22. The temperature measuring device 24 matrix is ​​arranged equidistantly in the horizontal and vertical directions. Each temperature measurement point corresponds to a coil 23 and a temperature measuring device 24 , and different temperature measuring devices 24 test different areas of the ferromagnetic material support plate 22 .

[0042] Before the cold start of the battery stack begins, the multi-channel high-frequency AC power supply in the controller 30 provides high-frequency AC with the same amplitude and frequency to different coils 23 in the coil 23 matrix. At the same time, the temperature measuring device 24 matrix begins to monitor the temperature of the ferromagnetic material support plate 22 and feeds the results back to the controller 30. The controller 30 adjusts the amplitude and frequency of the current in different channels according to the test results, and controls the uniform heating of different areas of the ferromagnetic material support plate 22. The heated end plate 21 transfers heat to the outermost single cell 10 of the battery stack in contact with the end plate 21 through heat conduction. After the single cell 10 is heated, it is not easy to have a single low during cold start, thereby improving the success rate of starting.

[0043] The utility model integrates a multi-channel high-frequency AC power supply in the controller. In the gas end plate 211 and the blind end plate 212, a ferromagnetic support plate 22, a coil 23 matrix and a temperature measuring device 24 matrix are installed respectively. The ferromagnetic support plate 22, the coil 23 matrix and the temperature measuring device 24 matrix are placed in parallel. Each coil 23 in the coil 23 matrix is ​​respectively connected to a channel of the AC power supply. Each temperature measuring point (temperature measuring device 24) in the temperature measuring device 24 matrix corresponds to each coil 23 one by one. The controller can receive the temperature value of each temperature measuring point in the temperature measuring device 24 matrix, and the controller can control the amplitude and frequency of the current of each channel of the AC power supply at all times. The controller controls the amplitude and frequency of the current in each coil 23 by adjusting the current of each channel, so that different coils 23 generate eddy currents of different sizes in the corresponding support plate area, thereby realizing end plate zone heating.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0046] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the present utility model, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previously associated objects are in an "or" relationship. "At least one" means one or more; "at least one of A and B" is similar to "A and / or B", describing the association relationship of associated objects, indicating that three relationships may exist. For example, at least one of A and B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0049] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fuel cell stack, characterized in that: include A plurality of stacked single cells (10); An end plate component (20) for limiting the positions of the plurality of stacked single cells (10) and for contacting the single cells (10) stacked on the outermost layer; Wherein, the end plate component (20) comprises an end plate (21), a ferromagnetic support plate (22), a coil (23) and a temperature measuring device (24); The ferromagnetic support plate (22) is loaded inside the end plate (21), and separates two opposite first plate portions (25) and second plate portions (26) of the end plate (21) inside the end plate (21), wherein the plate surface of the first plate portion (25) is in contact with the outermost single battery (10); The coil (23) is connected to an AC power source to generate a variable magnetic field, the coil (23) is arranged on the first plate portion (25), and the ferromagnetic support plate (22) is partially or completely within the range of the variable magnetic field that can be generated by the coil (23); The temperature measuring device (24) is arranged on the second plate portion (26) to collect the temperature of the ferromagnetic support plate (22).

2. The fuel cell stack according to claim 1, characterized in that: The end plate component (20) comprises an air port end plate (211) and / or a blind end plate (212); the coil (23) is arranged inside or on the surface of the first plate portion (25), and the temperature measuring device (24) is arranged inside or on the surface of the second plate portion (26).

3. The fuel cell stack according to claim 1, characterized in that: Also includes A controller (30), the controller (30) being connected to the temperature measuring device (24) and transmitting the temperature of the ferromagnetic support plate (22) collected by the temperature measuring device (24) to the controller (30); An alternating current power source is connected to the controller (30), and the controller (30) controls the coil (23) to be connected to the alternating current power source or to be disconnected from the alternating current power source.

4. The fuel cell stack according to claim 3, characterized in that: The AC power source is an AC power source with variable amplitude and frequency, and the controller (30) controls the amplitude and frequency of the AC power source.

5. The fuel cell stack according to claim 1, characterized in that: A plurality of the coils (23) are distributed at intervals on the first plate portion (25), and a plurality of the temperature measuring devices (24) are distributed at intervals on the second plate portion (26), and each coil (23) of the first plate portion (25) and each temperature measuring device (24) of the second plate portion (26) are arranged in a one-to-one correspondence, wherein a heating area corresponding to any coil (23) on the ferromagnetic support plate (22) is a temperature collection area corresponding to the temperature measuring device (24) corresponding to any coil (23) on the ferromagnetic support plate (22).

6. The fuel cell stack according to claim 5, characterized in that: Also includes A controller (30), the controller (30) being connected to the plurality of temperature measuring devices (24) and transmitting the temperatures of the plurality of positions of the ferromagnetic support plate (22) collected by the plurality of temperature measuring devices (24) to the controller (30); A multi-channel AC power supply, wherein the controller (30) is connected to the multi-channel AC power supply and controls one or more of the plurality of coils (23) to be connected to or disconnected from the corresponding channel AC power supply.

7. The fuel cell stack according to claim 6, characterized in that: The multi-channel AC power source is an AC power source with variable amplitude and frequency, and the controller (30) controls the amplitude and frequency of each channel AC power source.

8. The fuel cell stack according to claim 5, characterized in that: The plurality of coils (23) arranged on the first plate portion (25) are arranged at equal distances, and the plurality of temperature measuring devices arranged on the second plate portion (26) are arranged at equal distances.

9. The fuel cell stack according to claim 8, characterized in that: The plurality of equally spaced coils (23) of the first plate portion (25) are arranged in two or more equally spaced rows, and the plurality of equally spaced temperature measuring devices of the second plate portion (26) are arranged in two or more equally spaced rows.

10. A fuel cell, comprising the fuel cell stack according to any one of claims 1 to 9.

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