A phosphoric acid fuel cell stack and a method for detecting the health thereof

Abstract

The application provides a phosphoric acid fuel cell stack and a health detection method thereof. The phosphoric acid fuel cell stack is composed of a plurality of sub-stacks in series, and each sub-stack is separated by a cooling plate. The health factor alpha and the health factor beta of the phosphoric acid fuel cell stack are calculated, and the health factor alpha and the health factor beta are compared with the health boundary value to realize health monitoring. The application does not need a sub-stack voltage inspection monitoring device. Based on the overall voltage of the monitoring stack and the local voltage of the stack, the health factor is generated by comparing the stack voltage and the local voltage of the stack with the model prediction value, and the health monitoring of the sub-stack is realized. The method can effectively find the abnormal performance degradation of the sub-stack, provide early warning of failure and take corresponding stack control measures, avoid the failure of the sub-stack and improve the stability and reliability of the overall operation of the stack, and reduce the inspection and monitoring cost of the stack.

Description

Technical Field

[0001] This application belongs to the field of phosphoric acid fuel cell technology, and in particular relates to a phosphoric acid fuel cell stack and its health detection method. Background Technology

[0002] A phosphoric acid fuel cell is an electrochemical device that directly converts the chemical energy of fuel into electrical energy through an electrochemical reaction between hydrogen and oxygen in the presence of an electrocatalyst. Phosphoric acid fuel cells offer numerous significant advantages: high combined heat and power (CHP) energy conversion efficiency; zero carbon emissions, making them environmentally friendly; and low operating noise, highlighting their green and environmentally friendly characteristics. Based on these advantages, phosphoric acid fuel cells have been widely used in stationary power plants, particularly suitable for scenarios with high requirements for energy reliability and environmental friendliness, such as hospitals, commercial buildings, and data centers.

[0003] Phosphoric acid fuel cell stacks consist of multiple sub-stacks connected in series. Due to performance differences among the sub-stacks, their responses to changes in the overall operating conditions of the stack are inconsistent. Without sub-stack voltage monitoring equipment, health monitoring of each sub-stack within the stack is difficult, especially when abnormal performance degradation occurs, which cannot be detected and addressed in time, leading to sub-stack failures and ultimately causing the entire stack to malfunction or even shut down. This significantly increases stack maintenance and repair costs, making it necessary to monitor the health status of the sub-stacks. However, the cost and maintenance expenses of sub-stack voltage monitoring equipment increase with the number of sub-stacks. Therefore, it is necessary to develop a low-cost, simple, and effective sub-stack monitoring method. Summary of the Invention

[0004] The purpose of this application is to provide a phosphoric acid fuel cell stack and its health monitoring method, which does not require sub-stack voltage inspection and monitoring equipment, and realizes the health monitoring of the stack based on monitoring the overall voltage and local voltage of the stack.

[0005] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0006] In a first aspect, the present application provides that the battery stack is composed of multiple sub-battery stacks, each sub-battery stack being composed of several battery cell components stacked together, and each sub-battery stack being separated by a cooling plate.

[0007] The number of sub-cell stacks can be 20, 30, 45, 60, or other quantities, which can be set according to actual needs. Furthermore, the sub-cell stack is composed of multiple individual cells stacked together, and each individual cell can be 5, 8, 10, 20, or other quantities, which can also be set according to actual needs.

[0008] The cooling plate is mainly used to dissipate heat generated by the fuel cell stack. The cooling plate is mainly a layered structure made of conductive and acid-resistant carbon powder. The layers of the cooling plate are separated by allowing a cooling medium to flow through them to remove the waste heat generated by the fuel cell.

[0009] In some embodiments, the fuel cell stack includes a fuel cell voltage monitoring device and a fuel cell local voltage monitoring device, used to measure the fuel cell voltage and fuel cell local voltage, as well as the response of the fuel cell current and fuel cell operating conditions to changes.

[0010] In some embodiments, the fuel cell stack voltage monitoring device includes: a fuel cell stack anode cooling plate connection harness and a voltage measurement module, a fuel cell stack cathode cooling plate connection harness and a voltage measurement module; the fuel cell stack local voltage monitoring device includes: a fuel cell stack local cooling plate connection harness and a voltage measurement module.

[0011] In some embodiments, the local voltage monitoring device for the fuel cell stack is installed between the cathode and anode terminals of the fuel cell stack and at a location adjacent to a cooling plate in a designated sub-fuel cell stack; the fuel cell stack is divided into an upper region and a lower region along the stacking direction according to the location of the local voltage monitoring device, and the local voltage of the fuel cell stack includes the voltage of the upper region and the voltage of the lower region.

[0012] Secondly, this application provides a method for health testing of a phosphoric acid fuel cell stack, comprising the following steps:

[0013] S1: Obtain the stack voltage, stack local voltage, stack current, and stack parameters;

[0014] S2: Input the fuel cell stack parameters into the fuel cell stack mathematical model;

[0015] S3: Calculate the predicted voltage values ​​of the fuel cell stack, the upper region voltage of the fuel cell stack, and the lower region voltage of the fuel cell stack;

[0016] S4: Calculate the difference between the predicted and measured voltage values ​​of the sub-piles, calculate the difference between the predicted and measured voltage values ​​of the upper region of the pile, calculate the difference between the predicted and measured voltage values ​​of the upper region of the pile, calculate the difference between the predicted and measured voltage values ​​of the lower region of the pile, and generate the health factor α.

[0017] S5: Calculate the difference between the average voltage of the sub-piles in the upper region and the average voltage of the sub-piles in the lower region of the fuel cell stack based on the measured voltage values ​​of the upper and lower regions of the fuel cell stack, and generate the health factor β.

[0018] S6: Compare health factor α and health factor β with the health boundary value.

[0019] In some embodiments, step S3 includes:

[0020] The calculation method for the predicted value of the sub-pile voltage is as follows:

[0021] (1)

[0022] in The voltage prediction value of sub-pile i under current density I. This represents the initial factory voltage value of the sub-pile at the corresponding current density I. This is the voltage correction value for the steady-state performance degradation of the sub-pile. This is the voltage correction value for the degradation of the start-stop performance of the fuel cell stack. This is the voltage correction value for the hydrogen excess coefficient of the piezoelectric stack. It is the voltage correction value for the excess air coefficient of the piezoelectric stack;

[0023] (2)

[0024] Where n is the number of sub-piles that make up the fuel cell stack. This is the predicted voltage of the fuel cell stack at current density I;

[0025] (3)

[0026] Where m represents the number of sub-piles that make up the upper region of the fuel cell stack. The voltage prediction value of the upper region of the fuel cell stack under current density I; wherein, the number of sub-fuel cell stacks in the upper region of the fuel cell stack and the number of sub-fuel cell stacks in the lower region of the fuel cell stack can be the same or different.

[0027] (4)

[0028] Where w represents the number of sub-piles that make up the lower region of the fuel cell stack. This represents the predicted voltage value of the lower region of the fuel cell stack under current density I;

[0029] (5)

[0030] (6)

[0031] In some embodiments, step S4 includes:

[0032] The method for calculating the difference in average voltage of the sub-piles is as follows:

[0033] (7)

[0034] in This is the measured value of the fuel cell stack voltage;

[0035] The method for calculating the difference in average voltage between sub-piles in the upper region of the fuel cell stack is as follows:

[0036] (8)

[0037] in This is the measured voltage value of the upper region of the fuel cell stack;

[0038] The method for calculating the difference in average voltage between sub-stacking units in the lower region of the fuel cell stack is as follows:

[0039] (9)

[0040] in This is the measured voltage value of the lower region of the fuel cell stack;

[0041] The calculation method for health factor α is as follows:

[0042] (10)

[0043] in Number of individual cells in each sub-stack

[0044] In some embodiments, step S5 includes:

[0045] The method for calculating the difference in average voltage between the upper and lower regions of the fuel cell stack is as follows:

[0046] (11)

[0047] Health factors The calculation method is as follows:

[0048] (12)

[0049] In some embodiments, the stack parameters in S1 include at least one of the following: stack factory voltage-current curve, stack cumulative operating time, stack cumulative start-stop count, number of sub-stacking units in the stack, number of sub-stacking units in the upper region of the stack, number of sub-stacking units in the lower region of the stack, number of individual cells in the sub-stacking units, stack hydrogen excess coefficient, and stack air excess coefficient.

[0050] It should be noted that the hydrogen excess factor in a fuel cell stack refers to the ratio of the actual amount of hydrogen supplied to the amount of hydrogen required for the electrochemical reaction. It is typically used to optimize fuel cell performance and efficiency. An appropriate excess factor ensures complete reaction and avoids efficiency degradation due to insufficient hydrogen. Specifically, the hydrogen excess factor in a fuel cell stack is usually greater than 1, and can be any value within the range of 1.28, 1.42, 1.52, 1.82, and 2.0.

[0051] The excess air coefficient of the fuel cell stack controls the concentration polarization overpotential, and thus the heat generation, by controlling the excess air coefficient. For the same excess air coefficient, a higher current results in a higher concentration overpotential. However, for ease of control, the lowest concentration overpotential is used as the control value. The relationship between the excess air coefficient and the concentration overpotential is simplified to a curve; therefore, the concentration overpotential can be controlled by the excess air coefficient. Specifically, the excess air coefficient of the fuel cell stack is typically greater than 1, and can be any value within the range of 1.11, 1.22, 1.31, 1.52, 1.83, and 2.0.

[0052] In some embodiments, the difference between the absolute values ​​of health factor α and health factor β in S6, i.e. Compare with health boundary values.

[0053] The phosphoric acid fuel cell sub-stack health detection method provided in this application does not require sub-stack voltage inspection and monitoring equipment. Based on monitoring the overall voltage and local voltage of the fuel cell stack, a health factor is generated by comparing the stack voltage and local voltage with the model prediction value, thereby realizing the health monitoring of the sub-stack. This method can effectively detect abnormal performance degradation of the sub-stack, provide early warning of faults, and take corresponding stack control measures, avoiding sub-stack failure and improving the overall stability and reliability of the fuel cell stack operation, while reducing the inspection and monitoring cost of the fuel cell stack. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of the health detection method for phosphoric acid fuel cell stacks provided in an embodiment of the present invention;

[0056] Figure 2 This is a schematic diagram of the fuel cell stack voltage and fuel cell stack local voltage monitoring device provided in an embodiment of the present invention; Detailed Implementation

[0057] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0058] In the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0059] The first aspect of this application provides a phosphoric acid fuel cell stack, such as... Figure 2 As shown, the fuel cell stack is composed of multiple sub-stacks, with each sub-stack separated by a cooling plate.

[0060] In some embodiments, the fuel cell stack includes a fuel cell stack voltage monitoring device and a fuel cell stack local voltage monitoring device. The fuel cell stack anode cooling plate connection harness is connected to the voltage measurement module interface S1, the fuel cell stack cathode cooling plate connection harness is connected to the voltage measurement module interface S46, and the fuel cell stack local cooling plate connection harness is connected to the voltage measurement module interface S23.

[0061] In some embodiments, the local voltage monitoring device of the fuel cell stack is installed between the cathode and anode of the fuel cell stack to specify the location of the adjacent cooling plate of the sub-fuel cell stack 23, dividing the fuel cell stack along the stacking direction into an upper region (sub-fuel cell stack 1 to sub-fuel cell stack 22) and a lower region (sub-fuel cell stack 23 to sub-fuel cell stack 45).

[0062] The second aspect of this application provides a method for health detection of a phosphoric acid fuel cell stack. Figure 1 This is a schematic diagram of the health detection method provided in the application embodiment, including the following steps:

[0063] S1: Obtain the stack voltage, stack local voltage, stack current, and stack parameters;

[0064] S2: Input the fuel cell stack parameters into the fuel cell stack mathematical model;

[0065] S3: Calculate the predicted voltage values ​​of the fuel cell stack, the upper region voltage of the fuel cell stack, and the lower region voltage of the fuel cell stack;

[0066] S4: Calculate the difference between the predicted and measured voltage values ​​of the sub-piles, calculate the difference between the predicted and measured voltage values ​​of the upper region of the pile, calculate the difference between the predicted and measured voltage values ​​of the upper region of the pile, calculate the difference between the predicted and measured voltage values ​​of the lower region of the pile, and generate the health factor α.

[0067] S5: Calculate the difference between the average voltage of the sub-piles in the upper region and the average voltage of the sub-piles in the lower region of the fuel cell stack based on the measured voltage values ​​of the upper and lower regions of the fuel cell stack, and generate the health factor β.

[0068] S6: Compare health factor α and health factor β with the health boundary value.

[0069] In some embodiments, step S3 includes:

[0070] The calculation method for the predicted value of the sub-pile voltage is as follows:

[0071] (1)

[0072] in The voltage prediction value of sub-pile i under current density I. This represents the initial factory voltage value of the sub-pile at the corresponding current density I. This is the voltage correction value for the steady-state performance degradation of the sub-pile. This is the voltage correction value for the degradation of the start-stop performance of the fuel cell stack. This is the voltage correction value for the hydrogen excess coefficient of the piezoelectric stack. It is the voltage correction value for the excess air coefficient of the piezoelectric stack;

[0073] In some embodiments, Calculate the corresponding sub-pile voltage at current density I based on the factory-designed volt-ampere curve of sub-pile i.

[0074] In some embodiments, The calculation method is as follows:

[0075] (13)

[0076] in Accumulated operating time for the fuel cell stack The number of individual cells in the sub-pile;

[0077] In some embodiments, The calculation method is as follows:

[0078] (14)

[0079] in For the fuel cell stack during cumulative operating time Number of starts and stops within a time period;

[0080] In some embodiments, The calculation method is as follows:

[0081] (15)

[0082] in It is the hydrogen excess coefficient during the factory testing of the fuel cell stack. The excess hydrogen coefficient of the fuel cell stack;

[0083] In some embodiments, The calculation method is as follows:

[0084] (16)

[0085] in It is the excess air coefficient during the fuel cell stack's factory testing. This refers to the excess air coefficient of the fuel cell stack.

[0086] In some embodiments, The calculation method is as follows:

[0087] (2)

[0088] Where n is the number of sub-piles that make up the fuel cell stack. This is the predicted voltage of the fuel cell stack at current density I;

[0089] In some embodiments, The calculation method is as follows:

[0090] (3)

[0091] Where m represents the number of sub-piles that make up the upper region of the fuel cell stack. This represents the predicted voltage value of the upper region of the fuel cell stack under current density I;

[0092] In some embodiments, The calculation method is as follows:

[0093] (4)

[0094] Where w represents the number of sub-piles that make up the lower region of the fuel cell stack. This represents the predicted voltage value of the lower region of the fuel cell stack under current density I;

[0095] In some embodiments, , , The relationship is as follows:

[0096] (5)

[0097] In some embodiments, , , The relationship is as follows:

[0098] (6)

[0099] In some embodiments, step S4 includes:

[0100] The method for calculating the difference in average voltage of the sub-piles is as follows:

[0101] (7)

[0102] in This is the measured value of the fuel cell stack voltage;

[0103] The method for calculating the difference in average voltage between sub-piles in the upper region of the fuel cell stack is as follows:

[0104] (8)

[0105] in This is the measured voltage value of the upper region of the fuel cell stack;

[0106] The method for calculating the difference in average voltage between sub-stacking units in the lower region of the fuel cell stack is as follows:

[0107] (9)

[0108] in This is the measured voltage value of the lower region of the fuel cell stack;

[0109] The calculation method for health factor α is as follows:

[0110] (10)

[0111] In some embodiments, step S5 includes:

[0112] The method for calculating the difference in average voltage between the upper and lower regions of the fuel cell stack is as follows:

[0113] (11)

[0114] Health factors The calculation method is as follows:

[0115] (12)

[0116] In some embodiments, the stack parameters in S1 include at least one of the following: stack factory voltage-current curve, stack cumulative operating time, stack cumulative start-stop count, number of sub-stacking units in the stack, number of sub-stacking units in the upper region of the stack, number of sub-stacking units in the lower region of the stack, number of individual cells in the sub-stacking units, stack hydrogen excess coefficient, and stack air excess coefficient.

[0117] In some embodiments, the difference between the absolute values ​​of health factor α and health factor β in S6, i.e. Compared to the healthy boundary value (-20mV), such as If the voltage is less than -20mV, the system will alarm.

[0118] It should be noted that the health boundary value can be other values ​​such as -20mV, -10mV, and -5mV, and the health boundary value is set according to the actual situation.

[0119] The phosphoric acid fuel cell stack and its health monitoring method provided in this application embodiment do not require sub-stack voltage inspection and monitoring equipment. Based on monitoring the overall voltage and local voltage of the stack, health factors α and β are generated through the stack voltage, local voltage, and model prediction values. The health monitoring of the sub-stack is achieved by comparing the difference between the absolute values ​​of health factors α and β with the health boundary value. This method can effectively detect abnormal performance degradation of the sub-stack, provide early warning of faults, and take corresponding stack control measures, thereby avoiding sub-stack failure and improving the overall stability and reliability of the stack operation, while reducing the inspection and monitoring costs of the stack.

[0120] The following description is based on specific embodiments.

[0121] Example 1

[0122] The phosphoric acid fuel cell stack consists of 45 sub-stacks, such as... Figure 2 As shown, the connecting harness of the anode cooling plate of the fuel cell stack is connected to the voltage measurement module interface S1, and the connecting harness of the cathode cooling plate of the fuel cell stack is connected to the voltage measurement module interface S46. The fuel cell stack local voltage monitoring device is installed between the cathode and anode of the fuel cell stack at the location of the adjacent cooling plate of the designated sub-fuel cell stack 23, dividing the fuel cell stack into the upper region (sub-fuel cell stack 1 to sub-fuel cell stack 22) and the lower region (sub-fuel cell stack 23 to sub-fuel cell stack 45) along the stacking direction.

[0123] S1: Obtain stack voltage, stack local voltage, stack current, and stack parameters.

[0124] The number of neutron stacks in the fuel cell stack is 45.

[0125] The number of individual cells in the sub-pile is 8;

[0126] The excess air coefficient of the fuel cell stack is 2;

[0127] The hydrogen excess coefficient of the fuel cell stack is 1.43;

[0128] The hydrogen excess coefficient of the fuel cell stack was 1.25 during factory testing.

[0129] The excess air coefficient of the fuel cell stack was 1.67 during factory testing.

[0130] The upper region of the fuel cell stack includes 22 sub-fuel cell stacks;

[0131] The lower region of the fuel cell stack includes 23 sub-fuel cell stacks;

[0132] The cumulative operating time of the fuel cell stack is the cumulative operating time of the fuel cell stack under load conditions, and the cumulative operating time is 1000 hours;

[0133] The fuel cell stack has been started and stopped a total of 10 times.

[0134] The factory-set volt-ampere curve of the fuel cell stack is as follows: ;

[0135] The voltage values ​​of the sub-pile under the 450A factory test conditions are shown in Table 1;

[0136] The fuel cell stack operating time step is in 100-hour increments. Within this step, the average values ​​of the fuel cell stack voltage and current are: fuel cell stack current 442A, fuel cell stack voltage 231V, upper region voltage 112V, and lower region voltage 119V.

[0137] S2: Input the fuel cell stack parameters into the fuel cell stack mathematical model

[0138] Input the above data and parameters into the fuel cell model formulas (1) to (16).

[0139] S3: Based on the factory volt-ampere curve provided in S1, correct the voltage of the sub-staple under the 450A factory test condition to the voltage value under the actual stack current of 442A. The predicted values ​​of the sub-pile voltage were calculated according to formulas (1), (13), (14), (15), and (16), and the results are shown in Table 1.

[0140]

[0141]

[0142]

[0143]

[0144] The voltage of the fuel cell stack, the voltage of the upper region of the fuel cell stack, and the voltage of the lower region of the fuel cell stack are calculated according to formulas (2), (3), and (4):

[0145]

[0146]

[0147]

[0148] S4: Calculate the difference in average voltage of the sub-piles according to formulas (7), (8), and (9). The difference in average voltage of the sub-piles in the upper region of the pile and the difference in average voltage of the sub-piles in the lower region of the pile are:

[0149]

[0150]

[0151]

[0152] According to formula (10), the health factor α is:

[0153]

[0154] S5: According to formula (11) for:

[0155]

[0156] According to formula (12) health factors for:

[0157]

[0158] S6: Calculate the difference between the absolute values ​​of health factor α and health factor β, i.e. The comparison with the healthy boundary value (-20mV) yielded the following results:

[0159]

[0160] The system generated an alarm.

[0161] Table 1

[0162]

[0163] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A phosphoric acid fuel cell stack, characterized in that, The battery stack is composed of multiple sub-stacks, each of which is composed of several battery cell components stacked together, and each sub-stack is separated by a cooling plate.

2. The phosphoric acid fuel cell stack according to claim 1, characterized in that, The fuel cell stack includes a fuel cell voltage monitoring device and a fuel cell local voltage monitoring device, used to measure the response of the fuel cell voltage and fuel cell local voltage to changes in fuel cell current and fuel cell operating conditions.

3. The phosphoric acid fuel cell stack according to claim 1, characterized in that, The fuel cell stack voltage monitoring device includes: a fuel cell stack anode cooling plate connection harness and a voltage measurement module, a fuel cell stack cathode cooling plate connection harness and a voltage measurement module; the fuel cell stack local voltage monitoring device includes: a fuel cell stack local cooling plate connection harness and a voltage measurement module.

4. The phosphoric acid fuel cell stack according to claim 1, characterized in that, The local voltage monitoring device for the fuel cell stack is installed between the cathode and anode ends of the fuel cell stack and at a location adjacent to the cooling plate of a designated sub-fuel cell stack. Based on the location of the local voltage monitoring device, the fuel cell stack is divided into an upper region and a lower region along the stacking direction. The local voltage of the fuel cell stack includes the voltage of the upper region and the voltage of the lower region.

5. A method for health detection of a phosphoric acid fuel cell stack according to any one of claims 1-4, characterized in that, Includes the following steps: S1: Obtain the stack voltage, stack local voltage, stack current, and stack parameters; S2: Input the fuel cell stack parameters into the fuel cell stack mathematical model; S3: Calculate the predicted voltage values ​​of the fuel cell stack, the upper region voltage of the fuel cell stack, and the lower region voltage of the fuel cell stack; S4: Calculate the difference between the predicted and measured voltage values ​​of the sub-piles, calculate the difference between the predicted and measured voltage values ​​of the upper region of the pile, calculate the difference between the predicted and measured voltage values ​​of the upper region of the pile, calculate the difference between the predicted and measured voltage values ​​of the lower region of the pile, and generate the health factor α. S5: Calculate the difference between the average voltage of the sub-piles in the upper region and the average voltage of the sub-piles in the lower region of the fuel cell stack based on the measured voltage values ​​of the upper and lower regions of the fuel cell stack, and generate the health factor β. S6: Compare health factor α and health factor β with the health boundary value.

6. The detection method according to claim 5, characterized in that, Step S3 includes: The calculation method for the predicted value of the sub-pile voltage is as follows: (1) in The voltage prediction value of sub-pile i under current density I. This represents the initial factory voltage value of the sub-pile at the corresponding current density I. This is the voltage correction value for the steady-state performance degradation of the sub-pile. This is the voltage correction value for the degradation of the start-stop performance of the fuel cell stack. This is the voltage correction value for the hydrogen excess coefficient of the piezoelectric stack. This is the voltage correction value for the excess air coefficient of the sub-pile; and / or, (2) Where n is the number of sub-piles that make up the fuel cell stack. The predicted voltage of the fuel cell stack at current density I; and / or, (3) Where m represents the number of sub-piles that make up the upper region of the fuel cell stack. The predicted voltage value for the upper region of the fuel cell stack at current density I; and / or, (4) Where w represents the number of sub-piles that make up the lower region of the fuel cell stack. The predicted voltage value for the lower region of the fuel cell stack at current density I; and / or, (5) (6) 。 7. The detection method according to claim 5, characterized in that, Step S4 includes: The method for calculating the difference in average voltage of the sub-piles is as follows: (7) in This is the measured value of the fuel cell stack voltage; The method for calculating the difference in average voltage between sub-piles in the upper region of the fuel cell stack is as follows: (8) in This is the measured voltage value of the upper region of the fuel cell stack; The method for calculating the difference in average voltage between sub-stacking units in the lower region of the fuel cell stack is as follows: (9) in This is the measured voltage value of the lower region of the fuel cell stack; The calculation method for health factor α is as follows: (10) in The number of individual cells in each sub-pile.

8. The detection method according to claim 5, characterized in that, Step S5 includes: The method for calculating the difference in average voltage between the upper and lower regions of the fuel cell stack is as follows: (11) Health factors The calculation method is as follows: (12)。 9. The detection method according to claim 5, characterized in that, The stack parameters in S1 include at least one of the following: stack factory volt-ampere curve, stack cumulative operating time, stack cumulative start-stop count, number of sub-stacking units in the stack, number of sub-stacking units in the upper region of the stack, number of sub-stacking units in the lower region of the stack, number of individual cells in the sub-stacking units, stack hydrogen excess coefficient, and stack air excess coefficient.

10. The detection method according to claim 5, characterized in that, The difference between the absolute values ​​of health factor α and health factor β in S6, i.e. Compare with health boundary values.

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