Fuel cell stack partition potential and humidity distribution measuring device

Abstract

The invention relates to the technical field of fuel cells, and discloses a fuel cell stack partition potential and humidity distribution measuring device which comprises a first flow field microwell plate, a first sensor square hole plate, a PCB (printed circuit board), a second sensor square hole plate and a second flow field microwell plate which are sequentially stacked, a first small hole is formed in the position of the first flow channel groove part, a first opening is formed in the first sensor square hole plate and used for containing a first humidity sensor and a first potential sensor, and a second opening is formed in the second sensor square hole plate and used for containing a second humidity sensor and a second potential sensor. The second flow field microwell plate is provided with a second flow channel, a second small hole is formed in the groove position of the second flow channel, a circuit is arranged on the PCB, and the PCB is used for collecting voltage and humidity data. According to the invention, the partition potential and humidity distribution of the fuel cell stack can be measured at the same time, and the internal operation state of the fuel cell can be comprehensively reflected.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a measuring device for the potential and humidity distribution in different zones of a fuel cell stack. Background Art

[0002] At present, the fuel cell stack potential measuring devices used in the prior art usually take a single cell as the measurement object and mainly focus on its voltage distribution. However, this measurement method only reflects the potential difference between some areas of the cathode and the anode, and does not comprehensively consider independent factors such as the gas distribution and water management status of the cathode and the anode and their mutual influences. In addition, there are many patents on the measurement of the current in different zones in the prior art. However, the measurement of the current in different zones has the following limitations: firstly, the current is affected by the changes in voltage and internal resistance and cannot be used as an evaluation index alone; secondly, the current in different zones cannot reflect the real operating state inside the fuel cell when the current is zero. The uneven gas consumption and physical and chemical properties inside the fuel cell may lead to changes in voltage and current. For example, a higher humidity will accelerate the proton conduction speed, but if the temperature is lower, it may lead to a suitable humidity but an inappropriate temperature in the reaction cavity, thus affecting the current output. Therefore, relying solely on current measurement cannot comprehensively evaluate the operating state of the fuel cell. It is necessary to ensure the uniformity of the internal voltage and current at the same time to ensure the normal operation of the fuel cell stack. Therefore, a measuring device that can simultaneously measure the potential and humidity distribution in different zones inside the fuel cell is needed.

[0003] Further analysis shows that the humidity inside the fuel cell has a significant impact on the proton conduction speed and internal resistance, and is an important parameter affecting the performance of the fuel cell. Therefore, taking the potential distribution and humidity distribution as the physical quantities to be detected can provide guidance for the bipolar plate design and the uniformity of the internal reaction of the fuel cell, thereby improving the power density of the fuel cell. To sum up, the existing measuring devices for the potential and humidity distribution in different zones of the fuel cell stack have deficiencies in the measurement method and index selection and cannot comprehensively reflect the operating state of the fuel cell. In view of the above problems, it is of great practical significance and application value to research and design a new type of measuring device for the potential and humidity distribution in different zones of the fuel cell stack to overcome the defects in the prior art. Summary of the Invention

[0004] In order to solve the problem that the existing measurement of the potential and humidity distribution in different zones of the fuel cell stack only focuses on the voltage of a single cell and does not comprehensively consider the potential and humidity distribution in different zones, the present invention provides a measuring device for the potential and humidity distribution in different zones of a fuel cell stack.

[0005] The technical solution adopted by the present invention to achieve the above object is: a fuel cell stack partition potential and humidity distribution measuring device, including a first flow field microporous plate, a first sensor square hole plate, a PCB board, a second sensor square hole plate, and a first flow field microporous plate stacked in sequence. The first flow field microporous plate is provided with a first flow channel, and a plurality of first small holes are uniformly distributed at the groove position of the first flow channel. The first sensor square hole plate is provided with a plurality of first openings arranged in a matrix, and the first openings are used to place a first humidity sensor and a first potential sensor. The first humidity measurement probe of the first humidity sensor and the first potential measurement probe of the first potential sensor both pass through the first opening and abut against the side wall of the first small hole. The second sensor square hole plate is provided with a plurality of second openings arranged in a matrix, and the second openings are used to place a second humidity sensor and a second potential sensor. The second flow field microporous plate is provided with a second flow channel, and a plurality of second small holes are uniformly distributed at the groove position of the second flow channel. The second humidity measurement probe of the second humidity sensor and the second potential measurement probe of the second potential sensor both pass through the second opening and abut against the side wall of the second small hole. The PCB board is provided with a circuit, and the first humidity sensor, the first potential sensor, the second humidity sensor, and the second potential sensor are all connected to the circuit. The PCB board is used to collect voltage and humidity data.

[0006] According to a fuel cell stack partition potential and humidity distribution measuring device of some embodiments of the present invention, the diameter of the first small hole is 0.5-1 mm, and the first layout spacing of the first small holes at the groove position of the first flow channel is 1 / 5 to 1 / 2 of (length + width of the first flow field microporous plate), and the first layout spacing is the distance between the centers of adjacent first small holes.

[0007] According to a fuel cell stack partition potential and humidity distribution measuring device of some embodiments of the present invention, the diameter of the second small hole is 0.5-1 mm, and the second layout spacing of the second small holes at the groove position of the second flow channel is 1 / 5 to 1 / 2 of (length + width of the second flow field microporous plate), and the second layout spacing is the distance between the centers of adjacent second small holes.

[0008] According to a fuel cell stack partition potential and humidity distribution measuring device of some embodiments of the present invention, the shape of the first flow channel of the first flow field microporous plate is the same as the shape of the flow channel of the fuel cell anode plate, and the shape of the second flow channel of the second flow field microporous plate is the same as the shape of the flow channel of the fuel cell cathode plate.

[0009] A measuring device for the potential and humidity distribution of a fuel cell stack partition according to some embodiments of the present invention, wherein the shape of the first flow channel of the first flow field microplate is the same as the shape of the flow channel of the fuel cell cathode plate, and the shape of the second flow channel of the second flow field microplate is the same as the shape of the flow channel of the fuel cell anode plate.

[0010] A measuring device for the potential and humidity distribution of a fuel cell stack partition according to some embodiments of the present invention, wherein the surface of the first flow field microplate on the side away from the first sensor square hole plate is coated with a noble metal coating.

[0011] A measuring device for the potential and humidity distribution of a fuel cell stack partition according to some embodiments of the present invention, wherein the surface of the second flow field microplate on the side away from the second sensor square hole plate is coated with a noble metal coating.

[0012] A measuring device for the potential and humidity distribution of a fuel cell stack partition according to some embodiments of the present invention, wherein the first flow field microplate, the first sensor square hole plate, the PCB board, the second sensor square hole plate, and the first flow field microplate are integrally formed by thermoplastic synthesis.

[0013] A measuring device for the potential and humidity distribution of a fuel cell stack partition according to some embodiments of the present invention further includes a signal processing board, which is connected to the PCB board and is used to process the collected voltage and humidity data.

[0014] A measuring device for the potential and humidity distribution of a fuel cell stack partition according to some embodiments of the present invention, wherein the signal processing board is connected to the PCB board by a wire harness.

[0015] A measuring device for the potential and humidity distribution of a fuel cell stack partition of the present invention can comprehensively reflect the internal operating state of the fuel cell by simultaneously measuring the potential and humidity distribution of the fuel cell stack partition, overcoming the limitation of the prior art that only focuses on the single-cell voltage distribution. Compared with the prior art, the present device can not only more accurately evaluate the performance of the fuel cell, especially the internal state when the current is zero, but also provide more reliable data support for the optimized design. By introducing the joint measurement of potential and humidity distribution, the present device solves the deficiencies of the prior art and can more accurately evaluate the gas distribution, water management state, and non-uniformity of physical and chemical properties inside the fuel cell. The present device can adapt to the operating state of the fuel cell under different working conditions, especially when the humidity and temperature change greatly, and can still operate stably and provide accurate measurement data. This adaptability and reliability make the present device widely applicable in the research and development and practical application of fuel cells. While ensuring the measurement accuracy, the present device reduces the manufacturing and maintenance costs, and its modular design is convenient for installation and expansion, and can meet the measurement requirements of fuel cell stacks of different scales. Brief Description of the Drawings

[0016] Figure 1 It is a schematic explosion structure diagram of a measuring device for the potential and humidity distribution in zones of a fuel cell stack according to an embodiment of the present invention;

[0017] Figure 2 It is a three-dimensional structure diagram of the first sensor square hole plate according to an embodiment of the present invention;

[0018] Figure 3 It is a three-dimensional structure diagram of the PCB board according to an embodiment of the present invention.

[0019] In the figure: 1. The first flow field micro-hole plate, 2. The first sensor square hole plate, 3. The PCB board, 4. The second sensor square hole plate, 5. The second flow field micro-hole plate. Specific embodiments

[0020] The following further describes in detail the embodiments of the present invention in conjunction with the drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. The terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0022] A measuring device for the potential and humidity distribution in zones of a fuel cell stack in this embodiment is used to test the potential distribution and humidity distribution in the cathode and / or anode plane of the fuel cell stack, as Figure 1 and Figure 2As shown, it includes a first flow field microplate 1, a first sensor square hole plate 2, a PCB board 3, a second sensor square hole plate 4, and a first flow field microplate 1 stacked in sequence. The first flow field microplate 1 is provided with a first flow channel, and a plurality of first small holes are evenly distributed at the groove position of the first flow channel. The first sensor square hole plate 2 is provided with a plurality of first openings arranged in a matrix. The first openings are used to place a first humidity sensor and a first potential sensor. The first humidity measurement probe of the first humidity sensor and the first potential measurement probe of the first potential sensor both pass through the first openings and then abut against the side walls of the first small holes. The second sensor square hole plate 4 is provided with a plurality of second openings arranged in a matrix. The second openings are used to place a second humidity sensor and a second potential sensor. The second flow field microplate 5 is provided with a second flow channel, and a plurality of second small holes are evenly distributed at the groove position of the second flow channel. The second humidity measurement probe of the second humidity sensor and the second potential measurement probe of the second potential sensor both pass through the second openings and then abut against the side walls of the second small holes. The PCB board 3 is provided with a circuit, and the first humidity sensor, the first potential sensor, the second humidity sensor, and the second potential sensor are all connected to the circuit. The PCB board 3 is used to collect voltage and humidity data.

[0023] As a preference of this embodiment, more specifically, the diameter of the first small holes is 0.5 - 1 mm, and the first layout spacing of the first small holes at the groove position of the first flow channel is 1 / 5 to 1 / 2 of (the length of the first flow field microplate 1 + the width of the first flow field microplate 1). The first layout spacing is the distance between the centers of adjacent first small holes. The diameter of the second small holes is 0.5 - 1 mm, and the second layout spacing of the second small holes at the groove position of the second flow channel is 1 / 5 to 1 / 2 of (the length of the second flow field microplate 5 + the width of the second flow field microplate 5). The second layout spacing is the distance between the centers of adjacent second small holes. The first small holes can enable the reaction gas containing water vapor to be detected by the first humidity measurement probe and the first potential measurement probe. The second small holes can enable the reaction gas containing water vapor to be detected by the first humidity measurement probe and the first potential measurement probe. In addition, the first openings and the second openings are square holes. The position of each first small hole corresponds to that of the first opening. The diameter of each first opening is not greater than the side length of the corresponding first opening, and the lower edge of each first opening coincides with the lower edge of the corresponding first opening; the position of each second small hole corresponds to that of the second opening. The diameter of each second opening is not greater than the side length of the corresponding second opening, and the lower edge of each second opening coincides with the lower edge of the corresponding second opening.

[0024] Preferably, more specifically, in this embodiment, the shape of the first flow channel of the first flow field microplate 1 is the same as that of the flow channel of the fuel cell anode plate, and the shape of the second flow channel of the second flow field microplate 5 is the same as that of the flow channel of the fuel cell cathode plate. As another preference of this embodiment, more specifically, the shape of the first flow channel of the first flow field microplate 1 is the same as that of the flow channel of the fuel cell cathode plate, and the shape of the second flow channel of the second flow field microplate 5 is the same as that of the flow channel of the fuel cell anode plate. Both the first flow field microplate 1 and the second flow field microplate 5 are made of a metal material with good electrical conductivity. A noble metal coating is plated on the surface of the first flow field microplate 1 on the side away from the first sensor square hole plate 2, that is, a noble metal coating is plated on the surface of the first flow field microplate 1 on the side close to the membrane electrode. A noble metal coating is plated on the surface of the second flow field microplate 5 on the side away from the second sensor square hole plate 4, that is, a noble metal coating is plated on the surface of the second flow field microplate 5 on the side close to the membrane electrode.

[0025] Preferably, more specifically, in this embodiment, the first humidity measurement probe and the first potential measurement probe can be connected to the side wall of the first small hole by welding, and the first humidity measurement probe and the first potential measurement probe cannot block the first small hole. The second humidity measurement probe and the second potential measurement probe can be connected to the side wall of the second small hole by welding, and the second humidity measurement probe and the second potential measurement probe cannot block the second small hole.

[0026] Preferably, more specifically, in this embodiment, the first flow field microplate 1, the first sensor square hole plate 2, the PCB board 3, the second sensor square hole plate 4 and the first flow field microplate 1 are thermally molded into an integral structure to ensure good airtightness and no air leakage after the measuring device is installed in the fuel cell stack. The materials of both the first sensor square hole plate 2 and the second sensor square hole plate 4 are artificial graphite, and artificial graphite has strong pressure resistance and strong corrosion resistance, which can conduct current on the premise of ensuring corrosion resistance.

[0027] Conductive blocks are provided at the corresponding positions of the PCB board 3 and the first humidity sensor, the first potential sensor, the second humidity sensor and the second potential sensor. The size of the conductive block is a width of 1 to 8 mm outside the first opening and / or the second opening. The material of the conductive block can be a noble metal material, or the conductive block can be plated with a noble metal to conduct current. In addition, the conductive block can be a square block or a round block. In addition, each conductive block does not contact each other to avoid mutual interference, so that the humidity and potential characteristics of each measurement area can be clearly shown.

[0028] The first humidity sensor, the first potential sensor, the second humidity sensor and the second potential sensor are connected to the internal circuit of the PCB board 3 through square conductive blocks.

[0029] Preferably, more specifically, a device for measuring the partition potential and humidity distribution of a fuel cell stack according to this embodiment further includes a signal processing board, which is connected to the PCB board 3 and is used for processing the collected voltage and humidity data. The signal processing board and the PCB board 3 can be connected by a wire harness. A device for measuring the partition potential and humidity distribution of a fuel cell stack according to this embodiment further includes a host computer. The signal processing board exports the data to the host computer through communication established by a data line. The host computer saves the data and displays it on the host computer interface. And the host computer has a power supply for supplying power to the PCB board 2. The host computer is used for displaying the potential and humidity distribution diagrams, calculating the standard deviations of the potential and humidity, and storing the measurement data with time stamps.

[0030] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to better explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention so as to design various embodiments with various modifications suitable for specific purposes.

Claims

1. A measuring device for the potential and humidity distribution in partitions of a fuel cell stack, characterized in that, It includes a first flow field microplate (1), a first sensor square plate (2), a PCB board (3), a second sensor square plate (4) and a first flow field microplate (1) stacked in sequence. The first flow field microplate (1) is provided with a first flow channel, and a plurality of first small holes are evenly distributed at the groove position of the first flow channel. The first sensor square plate (2) is provided with a plurality of first openings arranged in a matrix. The first openings are used to place a first humidity sensor and a first electric potential sensor. The first humidity measurement probe of the first humidity sensor and the first electric potential measurement probe of the first electric potential sensor both pass through the first openings and then abut against the side walls of the first small holes. The second sensor square plate (4) is provided with a plurality of second openings arranged in a matrix. The second openings are used to place a second humidity sensor and a second electric potential sensor. The second flow field microplate (5) is provided with a second flow channel, and a plurality of second small holes are evenly distributed at the groove position of the second flow channel. The second humidity measurement probe of the second humidity sensor and the second electric potential measurement probe of the second electric potential sensor both pass through the second openings and then abut against the side walls of the second small holes. The PCB board (3) is provided with a circuit. The first humidity sensor, the first electric potential sensor, the second humidity sensor and the second electric potential sensor are all connected to the circuit. The PCB board (3) is used to collect voltage and humidity data.

2. The measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 1, wherein The diameter of the first small holes is 0.5 - 1 mm. The first layout spacing of the first small holes at the groove position of the first flow channel is 1 / 5 to 1 / 2 of (the length of the first flow field microplate (1) + the width of the first flow field microplate (1)). The first layout spacing is the distance between the centers of adjacent first small holes.

3. The measuring device for the partitioned potential and humidity distribution of a fuel cell stack according to claim 1, wherein The diameter of the second small holes is 0.5 - 1 mm. The second layout spacing of the second small holes at the groove position of the second flow channel is 1 / 5 to 1 / 2 of (the length of the second flow field microplate (5) + the width of the second flow field microplate (5)). The second layout spacing is the distance between the centers of adjacent second small holes.

4. A measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 3, characterized in that, The shape of the first flow channel of the first flow field microplate (1) is the same as the flow channel shape of the fuel cell anode plate. The shape of the second flow channel of the second flow field microplate (5) is the same as the flow channel shape of the fuel cell cathode plate.

5. A measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 1, characterized in that, The shape of the first flow channel of the first flow field microplate (1) is the same as the flow channel shape of the fuel cell cathode plate. The shape of the second flow channel of the second flow field microplate (5) is the same as the flow channel shape of the fuel cell anode plate.

6. The measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 1, wherein The surface of the first flow field microplate (1) on the side away from the first sensor square plate (2) is coated with a noble metal coating.

7. A measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 1, characterized in that, The surface of the second flow field microplate (5) on the side away from the second sensor square plate (4) is coated with a noble metal coating.

8. A measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 1, characterized in that, The first flow field microplate (1), the first sensor square plate (2), the PCB board (3), the second sensor square plate (4) and the first flow field microplate (1) are integrally formed by thermoplastic synthesis.

9. The measuring device for the partition potential and humidity distribution of a fuel cell stack according to claim 1, characterized in that, It further includes a signal processing board, which is connected to the PCB board (3) and is used for processing the collected voltage and humidity data.

10. The measuring device for the partitioned potential and humidity distribution of a fuel cell stack according to claim 9, characterized in that, The signal processing board is connected to the PCB board (3) through a wire harness.

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