Detection system for flow channel blockage fault of fuel cell polar plate

Abstract

The utility model discloses a fuel cell polar plate flow channel blockage fault detection system, which comprises a single cell voltage monitoring module electrically connected with a fuel cell, a test bench and a control upper computer, whether the air holes in the gap bridge area of the anode exhaust side of the single cell are blocked or not is judged according to the change curve of the voltage of the single cell in the test process.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a detection system for a fuel cell polar plate flow channel blockage fault. Background Art

[0002] Both sides of the bipolar plate of the fuel cell are provided with corresponding air flow channels, also known as bridge area pores. During the operation of the fuel cell, the gas on the anode inlet main channel enters the anode cavity of the single cell through the air flow inlet bridge area pores on the anode side of the bipolar plate, and is discharged to the anode exhaust main channel through the exhaust bridge area pores on the other side after the reaction is completed. The same process also occurs at the cathode. In the above-mentioned bridge area pores, the pore size of the anode is smaller than that of the cathode. At the same time, due to the recycling of the anode gas of the fuel cell, it is easy to cause the internal impurities of the anode to accumulate in the bridge area pores, making the anode air flow of the single cell unsmooth, reducing the stoichiometric ratio, resulting in a decrease in the performance of the single cell, and even causing the reverse polarity of the single cell in severe cases, causing irreversible damage to the membrane electrode. Due to the complex flow channels inside the single cell cavity and the driving effect of liquid water as a reaction product on impurities, the blockage of the anode bridge area pores often occurs on the exhaust side. In view of the above problems, the current detection can only determine whether there is a problem of clogging of the bridge area pores by directly observing the local area after disassembling the fuel cell. This method needs to be carried out in a scenario with the ability to disassemble the fuel cell, and has the problems of low detection efficiency and long cycle. It will also cause waste of some materials and increase the economic cost of maintenance. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a detection system and a detection method for a fuel cell plate flow channel blockage fault. In order to achieve the above purpose, the utility model provides a detection system for a fuel cell plate flow channel blockage fault, which includes: a single cell voltage monitoring module electrically connected to the fuel cell; a test bench, which includes an anode gas path and a cathode gas path, wherein the anode gas path: includes an anode inlet solenoid valve connected to the inlet end of the anode gas flow channel of the fuel cell, an anode back pressure valve connected to the outlet end of the anode gas flow channel of the fuel cell, and a hydrogen path and a nitrogen path respectively connected to the anode inlet solenoid valve, wherein the hydrogen path includes a hydrogen source, a hydrogen pressure reducing valve and a hydrogen supply solenoid valve in sequence, and the nitrogen path includes a nitrogen source, a nitrogen pressure reducing valve and a nitrogen supply solenoid valve in sequence; an anode inlet pressure sensor is also arranged between the anode inlet solenoid valve and the inlet end of the anode gas flow channel of the fuel cell; wherein the cathode gas path: includes a A cathode inlet solenoid valve connected to the inlet end of the air flow channel, a cathode back pressure valve connected to the outlet end of the cathode air flow channel of the fuel cell, and an air path connected to the cathode inlet solenoid valve, wherein the air path sequentially includes compressed air, a compressed air pressure reducing valve and an air supply solenoid valve; a cathode inlet pressure sensor is also arranged between the cathode inlet solenoid valve and the inlet end of the cathode air flow channel of the fuel cell; a control host computer, the control host computer is respectively connected to the hydrogen supply solenoid valve, nitrogen supply solenoid valve, anode inlet solenoid valve, anode inlet pressure sensor, anode back pressure valve, air supply solenoid valve, cathode inlet solenoid valve, cathode inlet pressure sensor and cathode back pressure valve in the test bench, and the control host computer is also connected to the single cell voltage monitoring module, the control host computer receives feedback signals from the above-mentioned connected components, and outputs corresponding control signals according to the feedback signals, and monitors and records the voltage data of the single cell voltage monitoring module at the same time.

[0004] The beneficial effects of the utility model are:

[0005] Compared with the prior art, the utility model can detect without disassembling the fuel cell, has high detection efficiency, and can determine the blockage status of the pores in the anode bridge area of ​​one or more fuel cell bipolar plates through one test; the implementation cost is low, and only a small amount of nitrogen and hydrogen is consumed in one test, and the fuel cell is not operated, and other materials are not wasted; it is easy to use, has low requirements on scene conditions, and can be implemented in any scene with fuel cell testing and operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The structure and further objects and advantages of the present invention will be better understood through the following description in conjunction with the accompanying drawings, in which the same reference numerals identify the same elements:

[0007] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model in practical application;

[0008] Figure 2 It is a curve of the single battery voltage changing with time. DETAILED DESCRIPTION

[0009] The specific implementation of the present utility model will be described below in conjunction with the accompanying drawings.

[0010] like Figure 1 As shown, according to one aspect of the utility model, a detection system for a fuel cell plate flow channel blockage fault is provided, which comprises: a single cell voltage monitoring module 14 electrically connected to the fuel cell; a test bench, which comprises an anode gas path and a cathode gas path, wherein the anode gas path comprises: an anode inlet solenoid valve 3 connected to the inlet end of the anode gas flow channel of the fuel cell, an anode back pressure valve 5 connected to the outlet end of the anode gas flow channel of the fuel cell, and a hydrogen path and a nitrogen path respectively connected to the anode inlet solenoid valve 3, wherein the hydrogen path comprises a hydrogen source, a hydrogen pressure reducing valve 1 and a hydrogen supply solenoid valve 2 in sequence, and the nitrogen path comprises a nitrogen source, a nitrogen pressure reducing valve 6 and a nitrogen supply solenoid valve 7 in sequence; an anode inlet pressure sensor 4 is also arranged between the anode inlet solenoid valve 3 and the inlet end of the anode gas flow channel of the fuel cell; wherein the cathode gas path comprises: a cathode inlet solenoid valve 10 connected to the inlet end of the cathode gas flow channel of the fuel cell, and a cathode back pressure valve 5 connected to the outlet end of the cathode gas flow channel of the fuel cell A cathode back pressure valve 12 connected to the outlet end, and an air path connected to the cathode inlet solenoid valve 10, wherein the air path includes compressed air, a compressed air pressure reducing valve 8 and an air supply solenoid valve 9 in sequence; a cathode inlet pressure sensor 11 is also arranged between the cathode inlet solenoid valve 10 and the inlet end of the cathode airflow channel of the fuel cell; a control host computer 15, the control host computer 15 is respectively connected to the hydrogen supply solenoid valve 2, the nitrogen supply solenoid valve 7, the anode inlet solenoid valve 3, the anode inlet pressure sensor 4, the anode back pressure valve 5, the air supply solenoid valve 9, the cathode inlet solenoid valve 10, the cathode inlet pressure sensor 11 and the cathode back pressure valve 12 in the test bench, and the control host computer 15 is also connected to the single cell voltage monitoring module 14, the control host computer 15 receives the feedback signals of the above-mentioned connected components, and outputs the corresponding control signals according to the feedback signals, and monitors and records the voltage data of the single cell voltage monitoring module 14 at the same time.

[0011] The working principle of the utility model is achieved through the following steps:

[0012] S1. Purge the anode chamber, cathode chamber and pipeline of the fuel cell with nitrogen and air to restore them to the required initial state:

[0013] The nitrogen supply solenoid valve 7 is opened by controlling the host computer 15, the pressure of the nitrogen pressure reducing valve 6 is adjusted to 120 kPa, and then the anode inlet solenoid valve 3 is opened, and the opening of the anode back pressure valve 5 is adjusted between 10 and 87 degrees, so that the pressure of the anode inlet pressure sensor 4 reaches 120 kPa, and it is maintained for 10 seconds; synchronously, the air supply solenoid valve 9 is opened by controlling the host computer 15, the pressure of the compressed air pressure reducing valve 8 is controlled to 110 kPa, and then the cathode inlet solenoid valve 10 is opened, and the opening of the cathode back pressure valve is adjusted between 10 and 87 degrees, so that the pressure of the cathode inlet pressure sensor 11 reaches 110 kPa, and it is maintained for 10 seconds;

[0014] S2. Add test gas hydrogen and air to the anode chamber, cathode chamber and pipeline of the fuel cell to fill them with test gas hydrogen and air:

[0015] By controlling the host computer 15 to first close the nitrogen supply solenoid valve 7, and then open the hydrogen supply solenoid valve 2, control the pressure of the hydrogen pressure reducing valve 1 to 120~150kPa, keep the anode inlet solenoid valve 3 in an open state, adjust the opening of the anode back pressure valve 5 between 10~87°, so that the pressure of the anode inlet pressure sensor 4 reaches 120~150kPa, and maintain it for 10 seconds; synchronously, keep the air supply solenoid valve 9 and the cathode inlet solenoid valve 10 in an open state, and then adjust the opening of the cathode back pressure valve 12 between 10~87°, so that the pressure of the cathode inlet pressure sensor 11 reaches 110~140kPa, and is 10~20kPa less than the pressure value of the anode inlet pressure sensor, and maintain it for 10 seconds;

[0016] S3. Start the test process and judge whether the single cell in the tested fuel cell has the problem of pore blockage in the bridge area on the anode exhaust side through the voltage change trend of each single cell:

[0017] By controlling the host computer 15 to close the hydrogen supply solenoid valve 2 and the anode inlet solenoid valve 3, the opening of the anode back pressure valve 5 is adjusted to the closed state; synchronously, the air supply solenoid valve 9 and the cathode inlet solenoid valve 10 are closed, and the opening of the cathode back pressure valve 12 is adjusted to the closed state. By controlling the host computer 15 to monitor and record the voltage of each single cell in the tested fuel cell, the average single cell voltage threshold is set to 0.1~0.2V as the end condition of the test, and the change curve of the single cell voltage during the test process is used to judge whether the single cell has the problem of pore blockage in the bridge area on the anode exhaust side.

[0018] The trend curve of the single cell voltage over time in the above three steps is as follows: Figure 2 As shown, the single cell with blocked pores in the bridge region on the anode exhaust side is called a faulty single cell, and the single cell without blocked pores in the bridge region on the anode exhaust side is called a normal single cell. Figure 2It can be seen that in the S2 stage, due to the blockage of the pores in the bridge area, the exhaust flow resistance is large. When the replacement is close to completion, the voltage rise trend slows down until the open circuit voltage stage (the so-called open circuit voltage stage refers to the period of time when the single cell voltage is the highest when the cathode end of the fuel cell is full of air and the anode end is full of hydrogen and is not consumed). The faulty single cell voltage slowly rises to the same level as the normal single cell voltage; in the S3 stage, due to the blockage of the pores in the bridge area, the trend of hydrogen in the anode cavity of the faulty single cell to diffuse outward is blocked. The voltage drop is mainly caused by the consumption of hydrogen after passing through the membrane electrode and reacting with oxygen, so its downward trend presents a curve close to linear, and the rate of decline is slower than that of the normal single cell. Therefore, the voltage change trend curve of the faulty single cell and the normal single cell over time can clearly determine which single cell is the faulty cell.

[0019] The utility model can detect without disassembling the fuel cell, and has high detection efficiency. Through one test, the blockage of the pores in the anode bridge area of ​​one or more fuel cell bipolar plates can be determined; the implementation cost is low, and only a small amount of nitrogen and hydrogen is consumed in one test, and the fuel cell is not operated, and other materials are not wasted; it is easy to use, has low requirements on scene conditions, and can be implemented in scenes with fuel cell testing and operation.

[0020] The technical content and technical features of the utility model have been disclosed above, but it can be understood that under the creative idea of ​​the utility model, those skilled in the art can make various changes and improvements to the above structure, including the combination of technical features disclosed or claimed separately here, and other combinations that obviously include these features. These deformations and / or combinations all fall within the technical field involved in the utility model and fall within the protection scope of the claims of the utility model.

Claims

1. A detection system for fuel cell plate flow channel blockage fault, characterized in that include: A single cell voltage monitoring module electrically connected to the fuel cell; A test bench, comprising an anode gas path and a cathode gas path, wherein the anode gas path comprises an anode inlet solenoid valve connected to the inlet end of the anode gas flow channel of the fuel cell, an anode back pressure valve connected to the outlet end of the anode gas flow channel of the fuel cell, and a hydrogen path and a nitrogen path respectively connected to the anode inlet solenoid valve, wherein the hydrogen path comprises a hydrogen source, a hydrogen pressure reducing valve and a hydrogen supply solenoid valve in sequence, and the nitrogen path comprises a nitrogen source, a nitrogen pressure reducing valve and a nitrogen supply solenoid valve in sequence; an anode inlet pressure sensor is further arranged between the anode inlet solenoid valve and the inlet end of the anode gas flow channel of the fuel cell; wherein the cathode gas path comprises a cathode inlet solenoid valve connected to the inlet end of the cathode gas flow channel of the fuel cell, a cathode back pressure valve connected to the outlet end of the cathode gas flow channel of the fuel cell, and an air path connected to the cathode inlet solenoid valve, wherein the air path comprises compressed air, a compressed air pressure reducing valve and an air supply solenoid valve in sequence; and a cathode inlet pressure sensor is further arranged between the cathode inlet solenoid valve and the inlet end of the cathode gas flow channel of the fuel cell; A control host computer is respectively connected to the hydrogen supply solenoid valve, nitrogen supply solenoid valve, anode inlet solenoid valve, anode inlet pressure sensor, anode back pressure valve, air supply solenoid valve, cathode inlet solenoid valve, cathode inlet pressure sensor and cathode back pressure valve in the test bench, and the control host computer is also connected to the single cell voltage monitoring module, the control host computer receives feedback signals from the above-connected components, and outputs corresponding control signals according to the feedback signals, and monitors and records the voltage data of the single cell voltage monitoring module.

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