A test method and control system for quickly calibrating the gas volume distribution of an electric pile

Abstract

The application discloses a kind of test method and control system of quick calibration electric pile gas distribution, specific steps include: selecting control electric pile;After electric pile is placed in test table, start test after starting, adjust gas flow in gradient, maintain preset time at each operating point, calculate average voltage value and calculate the first average voltage variation amplitude changed in different operating conditions;Set the first average voltage variation amplitude as standard value;Test electric pile is placed in test table, execute step 2-step 3, compare second average voltage variation amplitude with the first average voltage variation amplitude in preset operating condition range, judge single cell position gas distribution state according to comparison result.The application can accurately position the gas distribution state of each single cell in electric pile, to detect the safety and performance stability of electric pile, improve guarantee, which can also provide basis for subsequent electric pile optimization design and operating condition state monitoring, to further improve the life of electric pile.

Description

Technical Field

[0001] This invention relates to the technical field of fuel cells, and in particular to a test method and control system for rapidly calibrating the gas distribution of a fuel cell stack. Background Technology

[0002] A fuel cell stack is the core component of a fuel cell system. It uses hydrogen and oxygen to react chemically within the stack, producing water and electricity. The consistency of gas distribution within the fuel cell stack is crucial. Inconsistent gas flow distribution leads to imbalances in operating conditions between stacks, causing performance differences, affecting stack performance, and even causing safety issues. In fact, the consistency of gas flow distribution within a fuel cell stack deteriorates as the number of individual cells increases. Current technologies for detecting gas flow distribution consistency mostly use stack gas distribution diagnostic instruments, but this technology is not yet fully mature, is complex to operate, and requires a large supply of nitrogen, increasing testing costs. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art by proposing a test method and control system for rapidly calibrating the gas distribution of a fuel cell stack.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a test method for rapidly calibrating the gas distribution of a fuel cell stack, the specific steps of which include:

[0005] S1, Select the reference fuel cell stack;

[0006] S2, After placing the fuel cell stack in the test bench, start the test and apply a load to the preset constant current point;

[0007] S3, adjust the gas flow rate in a gradient within the preset operating range, maintain it for a preset time at each operating point, calculate the average voltage value and calculate the first average voltage change amplitude under different operating conditions.

[0008] S4, set the first average voltage change amplitude to a standard value;

[0009] S5, place the test stack in the test bench and execute steps S2-S3 to calculate the second average voltage change amplitude. Compare the second average voltage change amplitude with the first average voltage change amplitude within a preset operating range, and determine the gas distribution status of the single cell position in the test stack based on the comparison result.

[0010] As a further description of the above technical solution, in step S1, the number of single cell cells in the control stack is 10-30, so as to reduce the amount of calculation in step S3.

[0011] As a further description of the above technical solution, in step S3, the minimum preset operating condition range is 70-90%, the maximum preset operating condition range is 110%-200%, the preset time is 10-60 minutes, and the single gradient adjustment is 10%.

[0012] As a further description of the above technical solution, S5 also includes:

[0013] S51, within 70-90% of the operating conditions, if the amplitude of the second average voltage change is greater than the amplitude of the first average voltage change, and the difference exceeds the safety threshold, then it is determined that the gas distribution at the location of the single battery cell is relatively small.

[0014] S52, within the operating range of 110-200%, if the amplitude of the second average voltage change is less than the amplitude of the first average voltage change, and the difference exceeds the safety threshold, then it is determined that the gas distribution at the location of the single battery cell is relatively low.

[0015] As a further description of the above technical solution, the range of the security threshold is not less than 3mV.

[0016] As a further description of the above technical solution, in S2, the test station is a fuel cell stack test station, and when the control fuel cell stack test is performed and the test fuel cell stack test is performed, the fuel cell stack test station maintains normal operating conditions except that the gas flow rate changes in a gradient.

[0017] As a further description of the above technical solution, the formula for calculating the amplitude of the first average voltage change is as follows:

[0018] ΔU_first = U_check - U_previous

[0019] Among them, U 第一 This represents the average voltage change amplitude, in mV.

[0020] U 检 The first average voltage value detected at the current operating point, in mV;

[0021] U 前次 This is the first average voltage value detected at the previous operating point, in mV;

[0022]

[0023] Among them, U 第一 This is the first average voltage change amplitude, which is the standard value, and the unit is mV;

[0024] Un The average voltage change amplitude for the nth time is expressed in mV.

[0025] As a further description of the above technical solution, the formula for calculating the amplitude of the second average voltage change is as follows:

[0026] ΔU_second = U_inspection - U_previous

[0027] Among them, U 第二 This represents the second average voltage change amplitude, in mV.

[0028] U 检 This is the second average voltage value currently detected, in mV;

[0029] U 前次 This is the second average voltage value from the previous test, in mV.

[0030] A control system for rapidly calibrating the gas distribution of a fuel cell stack, the control system being used to execute any of the above-described methods for calibrating the gas distribution of a fuel cell stack.

[0031] The present invention has the following beneficial effects:

[0032] 1. This invention can quickly and easily calibrate the gas distribution within a fuel cell stack, especially for stacks with a large number of individual cells. The more cells there are, the more likely inconsistent gas distribution will occur. The detection steps in this application can accurately locate the gas distribution state of each individual cell in the stack, thereby improving stack safety and performance stability. It also provides a basis for subsequent stack optimization design and operational condition monitoring, further extending the stack's lifespan. Furthermore, it eliminates the need for specialized testing equipment such as fuel cell stack gas distribution diagnostic instruments, reducing costs. Attached Figure Description

[0033] Figure 1 This is a flowchart of the gas volume distribution test method. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Reference Figure 1 An embodiment of a test method for rapidly calibrating the gas distribution of a fuel cell stack provided by this invention is as follows: The specific steps are as follows:

[0036] S1. First, a control stack is selected. The purpose of setting up a control stack is to provide a comparable standard value when testing the stack under test. The number of individual cells in the selected control stack should not be too large, preferably 10-30 cells. This is to reduce the computational burden of subsequent average voltage calculations and to minimize interference from inconsistent gas distribution within the control stack itself due to a large number of individual cells, thus improving the reliability of the average voltage value and average voltage variation amplitude of the control stack. The remaining configurations of the control stack must be consistent with those of the test stack, specifically including the hydrogen supply system, air supply system, cooling system, water treatment system, and control system. In summary, by ensuring that the hardware configurations of the control stack and the test stack are identical, with only the number of individual cells differing, the accuracy of the control stack as a reference standard is improved, and errors are reduced.

[0037] S2, after placing the fuel cell stack in the test bench, start the test and load it to the preset constant current point. Here, the fuel cell stack is a control stack, and the test bench is a fuel cell stack test bench, a device used to test the performance and characteristics of fuel cells or other types of batteries. It typically includes a control system, measuring instruments, and a fuel cell stack support structure. The main function of the fuel cell stack test bench is to simulate the working state of the battery under actual application conditions and evaluate its performance parameters and dynamic characteristics. As this is a relatively mature existing technology, it will not be elaborated on further here. The purpose of loading the control stack to the preset constant current point is to ensure that the fuel cell stack reaches stable working conditions. In this embodiment, the constant current point can be 300-600A, which can be adjusted according to actual test requirements. This reduces the interference of additional variables on the average voltage change amplitude when adjusting the control stack later, improving the accuracy of the average voltage change amplitude as a standard value.

[0038] S3 adjusts the gas flow rate gradient within a preset operating range and maintains it at each operating point for a preset time. It then calculates the average voltage value at the corresponding operating point and the magnitude of the change in the average voltage value at adjacent operating points. The preset operating range includes a minimum range (gas flow rate 70-90%) and a maximum range (gas flow rate 110-200%). Each gradient adjustment is 10%, and the maintenance time at each operating point is 10-60 minutes. All other parameters remain within normal operating conditions, and the maintenance time can be adjusted according to actual conditions.

[0039] S4, set the first average voltage change amplitude as the standard value, the average voltage change amplitude as the difference between the average voltage values ​​of two adjacent operating points, and since the operating points change in a gradient manner, the average voltage value between each two adjacent operating points will generate an average voltage change amplitude, and the first average voltage change amplitude is the average of multiple average voltage change amplitudes, which is used as the standard reference value.

[0040] S5. After calculating the first average voltage change amplitude, the battery stack test bench is turned off, the control battery stack is taken out, and the test battery stack (i.e., the battery stack to be tested) is placed on the battery stack test bench for testing. When testing the test battery stack, the second average voltage change amplitude is calculated by referring to steps S2-S3. The parameters and test steps are the same as when testing the control battery stack.

[0041] It should be noted that after the test stack is tested on the stack test bench, a second average voltage change amplitude will be generated at each individual cell. Therefore, step S5 also includes the following steps:

[0042] S51, during the test within 70-90% of the minimum range of the initial working conditions, if the second average voltage change amplitude of a certain cell is 3-5mV or more greater than the first average voltage change amplitude of the control cell, it indicates that the gas distribution at the location of that cell is relatively low.

[0043] S52, if in the test of the maximum range of 110-200% of the initial working condition, if the second average voltage change amplitude of a certain cell is 3-5mV or even more less than the first average voltage change amplitude of the control stack, it indicates that the gas distribution of the single cell is relatively large.

[0044] The above-described detection method can quickly and easily calibrate the gas distribution within the fuel cell stack. For fuel cell stacks with a large number of individual cells, the more cells there are, the more likely inconsistent gas distribution will occur. The detection steps in this application can accurately locate the gas distribution status of each individual cell in the fuel cell stack, thereby improving the safety and performance stability of the fuel cell stack. It can also provide a basis for subsequent fuel cell stack optimization design and operational condition monitoring, thereby further improving the lifespan of the fuel cell stack.

[0045] The following formulas can be used to calculate the amplitude of the first average voltage change and the amplitude of the second average voltage change:

[0046] The formula for calculating the first average voltage change amplitude is:

[0047] ΔU = Udetected - Uprevious

[0048] Where U is the average voltage change amplitude, in mV;

[0049] U 检 The first average voltage value detected at the current operating point, in mV;

[0050] U 前次 This is the first average voltage value detected at the previous operating point, in mV.

[0051]

[0052] Among them, U 第一 This is the first average voltage change amplitude, which is the standard value, and the unit is mV;

[0053] U n This represents the average voltage change amplitude over the nth time, in mV.

[0054] The formula for calculating the second average voltage change amplitude is:

[0055] ΔU_second = U_inspection - U_previous

[0056] Among them, U 第二 This represents the second average voltage change amplitude, in mV.

[0057] U 检 This is the second average voltage value currently detected, in mV;

[0058] U 前次 This is the second average voltage value from the previous test, in mV.

[0059] During the comparison process, the second average voltage change amplitude of each individual cell, i.e., U... 第二 with U 第一 Calculations and comparisons are performed to determine the gas distribution state of the battery.

[0060] The present invention also provides a control system that can quickly stabilize the gas distribution of the fuel cell stack, the control system being used to execute any of the above-described calibration gas distribution test methods.

[0061] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test method for rapidly calibrating the gas distribution in a fuel cell stack, characterized in that, The specific steps include: S1, Select the reference fuel cell stack; S2, After placing the fuel cell stack in the test bench, start the test and apply a load to the preset constant current point; S3, adjust the gas flow rate in a gradient within the preset operating range, maintain it for a preset time at each operating point, calculate the average voltage value and calculate the first average voltage change amplitude under different operating conditions. S4, set the first average voltage change amplitude to a standard value; S5, place the test stack inside the test bench and execute steps S2-S3 to calculate the second average voltage change amplitude. Compare the second average voltage change amplitude with the first average voltage change amplitude within a preset operating range, and determine the gas distribution status of the single cell position in the test stack based on the comparison result. S5 also includes: S51, within the 70-90% operating range, if the second average voltage change amplitude is greater than the first average voltage change amplitude, and the difference exceeds the safety threshold, then it is determined that the gas distribution at the location of the single battery cell is relatively small. S52, within the operating range of 110-200%, if the amplitude of the second average voltage change is less than the amplitude of the first average voltage change, and the difference exceeds the safety threshold, then it is determined that there is a large amount of gas distribution at the location of the single battery cell. The range of the safety threshold is not less than 3mv.

2. The test method for rapidly calibrating the gas distribution of a fuel cell stack according to claim 1, characterized in that, In step S1, the number of individual cell cells in the control stack is 10-30 to reduce the amount of calculation in step S3.

3. The test method for rapidly calibrating the gas distribution of a fuel cell stack according to claim 1, characterized in that, In step S3, the minimum preset operating condition range is 70-90%, the maximum preset operating condition range is 110%-200%, the preset time is 10-60 minutes, and the single gradient adjustment is 10%.

4. The test method for rapidly calibrating the gas distribution of a fuel cell stack according to claim 1, characterized in that, In S2, the test bench is a fuel cell stack test bench, and when the control fuel cell stack test is performed and the test fuel cell stack test is performed, the fuel cell stack test bench maintains normal operating conditions except that the gas flow rate changes in a gradient.

5. A control system capable of rapidly calibrating the gas distribution of a fuel cell stack, characterized in that, The control system is used to perform the calibration fuel cell stack gas distribution test method as described in any one of claims 1-4.

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