A method of identifying a degree of clogging of an air filter in a hydrogen fuel cell system

Abstract

The application relates to the technical field of hydrogen fuel cells, and particularly discloses a method for identifying the clogging degree of an air filter in a hydrogen fuel cell system. 补偿 The preparation method comprises the following steps: converting the actual rotating speed NC of a current air compressor running under T1 conditions into the calibrated rotating speed NC of the air compressor under the calibrated temperature T0 through a temperature compensation model air , combining the calibrated air compressor alarm rotating speed N0, the current air flow m c‑air and the target air flow m 补偿 , and determining that the air filter reaches a clogging critical point and issuing a maintenance alarm signal when NC air >N0 and m c‑air <m . The application can eliminate the false alarm and missed alarm risks of a single parameter, accurately capture the clogging critical point of the filter, avoid cost waste caused by early maintenance, prevent damage to the hydrogen fuel cell stack caused by late maintenance, and significantly improve the system operation reliability and maintenance timeliness.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell technology, and particularly to a method for identifying the degree of clogging of air filters in a hydrogen fuel cell system. Background Technology

[0002] The hydrogen fuel cell engine is the core component of a hydrogen fuel cell vehicle. Its normal operation depends on the coordinated work of various subsystems, with the air subsystem being a crucial link. During the operation of the hydrogen fuel cell system, air, as one of the essential raw materials for the fuel cell reaction, must be filtered through an air filter before entering the system to participate in the reaction. The main function of the air filter is to remove particulate impurities and harmful gases from the air, preventing these substances from entering the fuel cell stack and avoiding contamination and damage to key components such as the catalyst and proton exchange membrane, thereby ensuring the performance and lifespan of the hydrogen fuel cell system.

[0003] With prolonged use, air filters accumulate a large amount of particulate impurities within the filter element, gradually weakening their chemical adsorption capacity and causing an increase in flow resistance. This increased flow resistance directly affects the flow rate and pressure of air entering the system, thus having a series of adverse effects on the operation of the hydrogen fuel cell system.

[0004] Currently, the common technical solution for determining the degree of air filter blockage is to install a mechanical maintenance indicator at the air filter outlet. Its working principle is that when the air filter's flow resistance reaches a certain level, the mechanical maintenance indicator will issue a warning signal through physical deformation, etc. The owner can then visually inspect the indicator's display and, when the air filter's performance degradation warning value is reached, perform maintenance or replace the air filter. However, this maintenance indicator uses a purely mechanical design, and its working status is highly susceptible to environmental factors such as vibration, humidity, and temperature during vehicle operation. Under long-term vibration, mechanical components may loosen or wear; changes in humidity may cause rust and corrosion; and drastic temperature fluctuations may affect the physical properties of the components, leading to decreased sensitivity or even failure of the indicator, making it unable to accurately reflect the actual degree of air filter blockage. Furthermore, the current monitoring method relies on visual inspection, requiring the owner to closely observe the mechanical maintenance indicator's status to determine if maintenance is needed. This method has significant limitations; the owner cannot monitor the air filter's status in real time while the vehicle is in motion, and can only check it when the vehicle is stopped, failing to achieve online monitoring during system operation. This could lead to the inability to detect in time when the air filter is already showing signs of clogging or has even reached the critical point of clogging, thus affecting the normal operation of the hydrogen fuel cell system.

[0005] Therefore, existing technologies still need to be improved and enhanced. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for identifying the degree of clogging of air filters in a hydrogen fuel cell system, aiming to solve the problem that it is difficult to accurately determine the critical point of clogging of air filters in a hydrogen fuel cell system.

[0007] The technical solution of the present invention is as follows: A method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system, comprising the steps of: Obtain the current actual air compressor speed NC, current operating ambient temperature T1, and current air flow rate m of the hydrogen fuel cell system. air and target airflow m c-air ; An air filter that is about to become clogged was selected as a test sample. The air filter that is about to become clogged is defined as an air filter whose degree of clogging does not affect the normal operation of the hydrogen fuel cell system, but will fail after running for another 100km. Under the normal ambient temperature conditions of the vehicle, the selected air filter that was about to become clogged was installed on the hydrogen fuel cell system test bench for testing, and the air compressor speed corresponding to different currents was collected in real time. The collected air compressor speed data under different fuel cell stack currents were analyzed and processed. After removing outliers, the air compressor speed corresponding to each fuel cell stack current was determined as the air compressor alarm speed N0 under that fuel cell stack current, and a correspondence graph between fuel cell stack current and air compressor alarm speed N0 was established. The actual air compressor speed NC under the current operating ambient temperature T1 is converted into the calibrated air compressor speed NC under the calibration temperature T0 using a temperature compensation model. 补偿 The calibration temperature T0 is the vehicle's common ambient temperature when the air compressor alarm speed N0 is calibrated. The calibrated air compressor speed NC 补偿 Compare with the air compressor alarm speed N0 under the corresponding current, and combine with the current air flow m air With the target airflow m c-air The relationship between the filter and the air filter is used to determine the degree of blockage. If NC 补偿 >N0 and m air <m c-air If the air filter reaches the critical blockage point, a maintenance alarm signal will be issued.

[0008] The method for identifying the degree of air filter blockage in a hydrogen fuel cell system includes obtaining the current actual air compressor speed NC, the current operating ambient temperature T1, and the current air flow rate m of the hydrogen fuel cell system.air and target airflow m c-air The steps include: The actual speed (NC) of the air compressor is obtained by using the eddy current speed sensor built into the air compressor. The current operating ambient temperature T1 is obtained by a temperature sensor installed at the air filter inlet; The current air flow rate (m) is obtained by a flow meter installed at the air compressor outlet. air ; The target airflow m is calculated in real time using the current stack current I, the number of stack cells N, and the stoichiometry k of the hydrogen fuel cell system. c-air Its calculation formula is: m c-air = k×N×I×M air / (4F) / 0.21, where k is the stoichiometric ratio of the reaction, with a value of 1.7-2; F is the Faraday constant, M air This is the molar mass of air. The method for identifying the degree of air filter blockage in a hydrogen fuel cell system, wherein the operational fault is the actual airflow rate m air Continuously below the target airflow m c-air One or more of the following: the average voltage of a single fuel cell stack is less than 90% of the target average voltage of that single cell, or the cathode inlet pressure of the fuel cell stack is less than 90% of the target value.

[0009] The method for identifying the degree of air filter blockage in a hydrogen fuel cell system includes using a temperature compensation model to convert the actual air compressor speed NC under the current operating ambient temperature T1 into the calibrated air compressor speed NC under the calibrated temperature T0. 补偿 The steps include: Air compressor speeds under the same operating conditions were collected at different ambient temperatures. A temperature compensation model was established to reflect the relationship between ambient temperature and air compressor speed changes. This temperature compensation model is expressed as: NC 补偿 =NC* Wherein, the units of the calibration temperature T0 and the current ambient temperature T1 are K, NC 补偿 To calibrate the air compressor speed; The actual air compressor speed NC and the current operating ambient temperature T1, collected in real time, are substituted into the temperature compensation model to calculate the calibrated air compressor speed NC. 补偿 .

[0010] Beneficial Effects: The method for identifying the degree of air filter clogging in a hydrogen fuel cell system provided by this invention effectively eliminates the influence of various interference factors through scientific calibration of the air compressor alarm speed and ambient temperature compensation. This makes the judgment of the degree of air filter clogging more accurate, accurately identifying the clogging critical point, avoiding resource waste caused by premature maintenance and damage to the system caused by delayed maintenance. Furthermore, this invention also combines the air compressor speed (after temperature compensation) and the relationship between air flow and target flow for comprehensive judgment, avoiding the limitations of single-parameter judgment and improving the reliability of the judgment. Compared with existing technologies, this invention is more comprehensive and scientific. This invention realizes real-time online monitoring of the degree of air filter clogging and active system alarm. Compared with existing technologies, it can timely and accurately determine the clogging critical point, reduce unnecessary maintenance, reduce the risk of system failure due to clogging, significantly improve the operational stability and economy of the hydrogen fuel cell system, and extend the system's service life, demonstrating significant technological progress. Attached Figure Description

[0011] Figure 1 This is a flowchart of a method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system according to the present invention.

[0012] Figure 2 This is a schematic diagram of the air subsystem structure in the hydrogen fuel cell system of the present invention.

[0013] Figure 3 This is a calibration diagram for the current-air compressor alarm speed.

[0014] Figure 4 The image shows a scatter plot of the airflow-current relationship of the fuel cell electric vehicle with license plate number Yue E07211 in Example 1 after running 16156km and replacing the air filter, under the same current load.

[0015] Figure 5 The image shows a scatter plot of the air compressor speed-current relationship after the fuel cell electric vehicle with license plate number Yue E07211 in Example 1 has run for 16,156 km and the air filter has been replaced, with the same load current. Detailed Implementation

[0016] This invention provides a method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] Please see Figure 1 , Figure 1 A flowchart of a method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system, provided by the present invention, is shown in the figure, and includes the following steps: S10. Obtain the current actual air compressor speed NC, current operating ambient temperature T1, and current air flow rate m of the hydrogen fuel cell system. air and target airflow m c-air ; Specifically, the air subsystem in the hydrogen fuel cell system is as follows: Figure 2 As shown, it includes an air filter, flow meter, thermometer, air compressor, intercooler, and humidifier connected in sequence. The humidifier has dry and wet circuits. The dry side outlet connects to the cathode inlet of the hydrogen fuel cell, and the wet side inlet connects to the cathode outlet of the fuel cell stack. The wet side outlet is connected in sequence to a back pressure valve and a silencer. In terms of airflow direction, the air first passes through the air filter to remove impurities, then flows through the flow meter (for measuring airflow) and the thermometer (for detecting air temperature). Next, it enters the air compressor to compress the air and increase its pressure. The compressed, high-temperature air enters the intercooler for cooling. The cooled air passes through a shut-off valve (to control airflow) and then enters the dry side of the humidifier. The cathode exhaust gas in the wet side of the humidifier humidifies the dry side air to meet the humidity requirements of the cathode reaction. The humidified air enters the fuel cell cathode to participate in the electrochemical reaction. The fuel cell stack cathode is equipped with a pressure gauge to monitor the cathode inlet pressure in real time. The high-humidity exhaust gas at the fuel cell stack cathode outlet flows into the wet side of the humidifier, exits from the wet side outlet, then flows through the back pressure valve and the silencer, and finally is discharged into the atmosphere.

[0018] In this embodiment, the actual speed NC of the air compressor can be obtained by the eddy current speed sensor built into the air compressor. The eddy current speed sensor can work stably in the temperature range of -40℃ to 200℃ and the sampling frequency is 300kHz, ensuring real-time and accurate monitoring of the air compressor speed. The current operating ambient temperature T1 is obtained by a temperature sensor (i.e., thermometer) installed at the air inlet of the air filter. The temperature sensor can be a high-precision thermocouple sensor with a measurement range of -50℃ to 150℃ and an accuracy of ±0.5℃, which can accurately reflect the ambient temperature of the air filter. The current air flow rate (m) is obtained by a flow meter installed at the air compressor outlet. air The flow meter can be a thermal mass flow meter with a measurement accuracy of ±1% of full scale and a response time of less than 10ms, which can accurately measure the air flow entering the system. The target airflow m is calculated in real time using the current stack current I, the number of individual cells N in the hydrogen fuel cell system, and the stoichiometry k. c-air Its calculation formula is: m c-air = k×N×I×M air / (4F) / 0.21, where k is the stoichiometric ratio of the reaction, with a value of 1.7-2; F is the Faraday constant, Mair Let m be the molar mass of air. Target airflow rate (m). c-air It is calculated based on the current operating conditions of the hydrogen fuel cell system and represents the air flow required to ensure normal system operation.

[0019] S20. Select an air filter that is about to become clogged as a test sample. The air filter that is about to become clogged is defined as: an air filter whose degree of clogging does not affect the normal operation of the hydrogen fuel cell system, but will fail after running for another 100km. S30. Under the normal ambient temperature conditions of the vehicle, the selected air filter that is about to become clogged is installed on the hydrogen fuel cell system test bench for testing, and the air compressor speed corresponding to different currents is collected in real time. S40. Analyze and process the collected air compressor speed data under different currents, remove outliers, determine the air compressor speed corresponding to each current as the air compressor alarm speed N0 under that current, and establish a correspondence graph between current and air compressor alarm speed N0. Specifically, steps S20-S40 are the calibration steps for the air compressor alarm speed N0. This step is one of the key steps in this invention, and its specific calibration process is as follows: Sample Selection: Air filters that are about to become clogged were selected as test samples. An air filter about to become clogged was defined as one whose degree of clogging does not affect the normal operation of the hydrogen fuel cell system, but will experience operational failure after running for another 100km. The operational failure is defined as an actual airflow rate of m³ / s. air One or more of the following are not met: the average voltage of individual fuel cell units is lower than the preset value, or the cathode inlet pressure of the fuel cell stack is not up to standard. For example, the actual airflow rate m... air Not meeting the standard means the actual airflow rate (m) air Continuously below the target airflow m c-air The target average voltage and target pressure are set by the system based on the operating conditions. The definition ensures that the air compressor alarm speed corresponds to a critical state requiring maintenance, rather than a state of failure. The average voltage of a single fuel cell unit is below 90% of the preset value; the average voltage of a single fuel cell unit is below 90% of the target average voltage for that current; the average voltage of a single fuel cell unit is below 90% of the preset value; the average voltage of a single fuel cell unit is below 90% of the target value .... This definition ensures that the alarm speed of the air compressor corresponds to a critical state requiring maintenance, rather than a state of failure

[0020] Test environment: Under the normal ambient temperature conditions of vehicles (25℃±2℃), the selected air filter that is about to become clogged will be installed on the system test bench for testing; the test bench needs to simulate various operating conditions of the vehicle in actual operation, including different loads, speeds, etc., to ensure the authenticity and reliability of the test conditions.

[0021] Data Acquisition: During testing, the air compressor speed was collected in real time under different stack currents using testing equipment on the system bench. The test current range covered the commonly used operating current range of hydrogen fuel cell system stacks, starting from the stack current (I0) at idle speed. 怠速 ) to maximum operating current (e.g., I MAX The current is measured at regular intervals (e.g., 20A) to ensure that the collected data can fully reflect the air compressor speed under different operating conditions. For example, when the current is 100A, the measured speed is 50000r / min, then N0(100A) = 50000r / min. The test is repeated 3 times, and the average value is taken as the final threshold to reduce the influence of random errors.

[0022] Determine the alarm speed: Analyze and process the collected air compressor speed data under different fuel cell stack currents, remove outliers, and determine the air compressor speed corresponding to each fuel cell stack current as the air compressor alarm speed N0 under that fuel cell stack current. Establish a correspondence graph between fuel cell stack current and air compressor alarm speed, as shown in Figure 3.

[0023] This embodiment uses a filter that is about to become clogged as a sample and combines bench simulation of actual working conditions to make the alarm threshold closer to the actual use scenario of the vehicle. Compared with the fixed flow resistance threshold in the prior art, the judgment accuracy is improved to more than 95%. By establishing a current-alarm speed dynamic spectrum, the problem of threshold adaptation under different working conditions is solved. For example, the alarm speed is higher under high current conditions, avoiding false judgments under low current conditions.

[0024] S50. Using a temperature compensation model, the actual speed NC of the current air compressor operating at the current ambient temperature T1 is converted into the calibrated air compressor speed NC at the calibrated temperature T0. 补偿 The calibration temperature T0 is the vehicle's common ambient temperature when the air compressor alarm speed N0 is calibrated. Specifically, temperature changes alter air density, thus affecting the air compressor's speed. To eliminate this interference, the current actual air compressor speed NC needs to be converted to the calibrated air compressor speed NC at the calibrated temperature T0. 补偿 Specifically, this embodiment analyzes the relationship between ambient temperature and air compressor speed through a large amount of experimental data. Experiments were conducted at different ambient temperatures (e.g., -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃, 50℃, etc.), and air compressor speeds were collected under the same operating conditions (same current, same degree of air filter blockage). A temperature compensation model for the change in ambient temperature and air compressor speed was established. This temperature compensation model is expressed as: NC 补偿 =NC* When using this formula, the Celsius temperature (t, in °C) of the calibration temperature T0 and the current ambient temperature T1 needs to be converted to Kelvin temperature (T, in K), where T = t + 273.15, and NC 补偿 To calibrate the air compressor speed; The actual air compressor speed NC and the current operating ambient temperature T1, collected in real time, are substituted into the temperature compensation model to calculate the calibrated air compressor speed NC. 补偿 .

[0025] This embodiment can effectively eliminate the interference of temperature on rotational speed through a temperature compensation model, reducing the alarm rotational speed error from ±8% to within ±2%. For example, in a high-temperature (40℃) environment, without compensation, NC=100000r / min may be mistakenly judged as exceeding the standard (actually equivalent to 97575r / min at 25℃; if the alarm rotational speed N0=99000r / min, it is not exceeding the standard). Compensation can avoid such false alarms.

[0026] S60, calibrate the air compressor speed NC 补偿 Compare with the air compressor alarm speed N0 under the corresponding current, and combine with the current air flow m air With the target airflow m c-air The relationship between the filter and the air filter is used to determine the degree of blockage. S70, if NC 补偿 >N0 and m air <m c-air If the air filter reaches the critical blockage point, a maintenance alarm signal will be issued.

[0027] Specifically, this embodiment requires simultaneous NC 补偿 >N0 and m air <m c-air The core reason for using two parameters to determine the critical point of air filter clogging is that they provide complementary verification, eliminate the limitations of a single parameter, and ensure the accuracy and reliability of the judgment. A detailed analysis follows: NC 补偿 This is the actual speed of the air compressor after temperature compensation, which eliminates the interference of ambient temperature on the speed (high temperatures reduce air density, requiring the air compressor to operate at a higher speed to maintain flow); while N0 is the calibrated alarm speed (corresponding to the critical speed of an air filter about to become clogged under the same operating conditions); when NC 补偿 A value greater than N0 indicates that the air compressor's speed has exceeded the critical value in order to overcome the air filter's flow resistance and maintain the target flow rate. However, using this alone for judgment has limitations: if the air compressor itself malfunctions (such as a short-term inverter failure) or experiences instantaneous load fluctuations (such as a sudden decrease in downstream air volume), it may also lead to N0. 补偿If the air level briefly exceeds N0, the air filter may not be clogged, posing a risk of false alarm.

[0028] m air It is the actual current airflow entering the system, in meters. c-air This is the target airflow rate calculated by the system based on operating conditions; it is the minimum air volume required to ensure normal operation of the fuel cell stack. When m air <m c-air When the airflow meter malfunctions (e.g., displaying a low value) or the air compressor experiences a momentary stall (e.g., due to intermittent sensor malfunction), it indicates insufficient airflow supply, with a clogged air filter being the primary cause. However, relying solely on this criterion has limitations: a faulty airflow meter (e.g., displaying a low value) or a momentary stall in the air compressor (e.g., due to an intermittent sensor malfunction) could also cause insufficient airflow. air Briefly below m c-air At this point, the air filter may not be clogged, but there is still a risk of false alarms. Furthermore, if the flow resistance has not yet increased significantly in the initial stage of filter clogging, the air compressor can maintain flow by slightly increasing its speed. In this case, the NC... 补偿 Not exceeding N0, but m air It may be approaching the critical value, and there is also a risk of underreporting.

[0029] This embodiment eliminates blind spots through dual-parameter collaborative judgment and complementary verification. Only when the rotational speed exceeds the limit (NC... 补偿 >N0) and insufficient flow (m air <m c-air Only when both of these conditions occur simultaneously can it be reliably determined that the air filter has reached the critical point of blockage, for the following reasons: The core impact of filter clogging is "increased flow resistance → the air compressor needs to increase its speed to deliver the same flow rate → if the speed is increased to its limit and the flow rate still cannot be met, then the clogging is irreversible." NC 补偿 >N0 indicates that the air compressor is operating at full capacity (speed exceeds the critical value); m air <m c-air This indicates that even at full speed, the flow rate demand cannot be met. Combined, these two factors point directly to excessive air filter resistance, meaning the system can no longer maintain normal flow by increasing the engine speed – this is the core characteristic of the clogging critical point.

[0030] This invention achieves the following technical advantages through dual-parameter collaborative judgment: Avoid false alarms: It eliminates interference from non-blocking factors such as air compressor malfunction and sensor fluctuations; Avoid missed detections: Capture the initial stage of blockage where flow resistance increases but flow rate does not decrease significantly (at this time, NC 补偿 >N0, but m air It may be just close to m c-air ); Precisely triggering maintenance timing: An alarm is triggered when the air filter reaches a critical blockage point (where further operation would affect the system), avoiding both premature maintenance (wasting costs) and delayed maintenance (damaging the fuel cell stack). In summary, dual-parameter collaborative judgment is one of the core innovations of this invention. Through a causal closed loop of excessive speed + insufficient flow, the critical blockage point of the air filter is precisely located, solving the problem of misjudgment caused by relying on a single parameter in existing technologies.

[0031] The present invention will be further explained and illustrated below through specific embodiments: Example 1 1. Experimental Preparation The fuel cell electric vehicle with license plate number Yue E07211 was used as the experimental subject. This vehicle had run 16,156 km without replacing its air filter, and a replaced air filter was prepared as a comparison sample. The experimental equipment included a data acquisition system, a high-precision speed sensor, a temperature sensor, and an air flow meter. All equipment was calibrated to ensure measurement accuracy.

[0032] 2. Parameter Acquisition and Analysis Parameter acquisition: During vehicle operation, the actual compressor speed (NC), ambient temperature (T1), and air flow rate (m³ / s) are collected in real time under different current conditions. air ), and calculate the target airflow (m³) based on the system operating conditions. c-air At the same time, the same parameters were collected from vehicles whose air filters had been replaced.

[0033] Data Comparison: Comparing the parameter data of the fuel cell electric vehicle with license plate number Yue E07211 after running 16156km (without air filter replacement) and after replacing the air filter, under the same current, the results are as follows. Figure 4 and Figure 5As shown in the figure, under the same current, the airflow without replacing the air filter is lower than the airflow after replacement, while the air compressor speed is higher. This indicates that air filter blockage leads to a decrease in airflow and an increase in air compressor speed, which is consistent with the technical principle of this invention. Furthermore, the collected parameters for both the unreplaced and replaced air filters are substituted into the judgment method of this invention for verification. For a vehicle with an unreplaced air filter and a mileage close to 16156 km, under partial current, the temperature-compensated air compressor speed exceeds the corresponding alarm speed, and the airflow is lower than the target airflow, triggering an alarm signal. However, after replacing the air filter, under the same current, the compensated air compressor speed is lower than the alarm speed, the airflow reaches the target flow, and the system does not issue an alarm signal, verifying the effectiveness of the judgment method of this invention. It should be understood that the application of this invention is not limited to the examples described above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system, characterized in that, Including the following steps: Obtain the current actual air compressor speed NC, current operating ambient temperature T1, and current air flow rate m of the hydrogen fuel cell system. air and target airflow m c-air ; An air filter that is about to become clogged was selected as a test sample. The air filter that is about to become clogged is defined as an air filter whose degree of clogging does not affect the normal operation of the hydrogen fuel cell system, but will fail after running for another 100km. Under the normal ambient temperature conditions of the vehicle, the selected air filter that was about to become clogged was installed on the hydrogen fuel cell system test bench for testing, and the air compressor speed corresponding to different stack currents was collected in real time. The collected air compressor speed data under different fuel cell stack currents were analyzed and processed. After removing outliers, the air compressor speed corresponding to each current was determined as the air compressor alarm speed N0 under that fuel cell stack current, and a correspondence graph between fuel cell stack current and air compressor alarm speed N0 was established. The actual air compressor speed NC under the current operating ambient temperature T1 is converted into the calibrated air compressor speed NC under the calibration temperature T0 using a temperature compensation model. 补偿 The calibration temperature T0 is the vehicle's common ambient temperature when the air compressor alarm speed N0 is calibrated. The calibrated air compressor speed NC 补偿 Compare with the air compressor alarm speed N0 under the corresponding current, and combine with the current air flow m air With the target airflow m c-air The relationship between the filter and the air filter is used to determine the degree of blockage. If NC 补偿 >N0 and m air <m c-air If the air filter reaches the critical blockage point, a maintenance alarm signal will be issued.

2. The method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system according to claim 1, characterized in that, Obtain the current actual air compressor speed NC, current operating ambient temperature T1, and current air flow rate m of the hydrogen fuel cell system. air and target airflow m c-air The steps include: The actual speed (NC) of the air compressor is obtained by using the eddy current speed sensor built into the air compressor. The current operating ambient temperature T1 is obtained by a temperature sensor installed at the air filter inlet; The current air flow rate (m) is obtained by a flow meter installed at the air compressor outlet. air ; The target airflow m is calculated in real time using the current stack current I, the number of stack cells N, and the stoichiometry k of the hydrogen fuel cell system. c-air Its calculation formula is: m c-air = k×N×I×M air / (4F) / 0.21, where k is the stoichiometric ratio of the reaction, with a value of 1.7~2; F is the Faraday constant, M air This is the molar mass of air.

3. The method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system according to claim 1, characterized in that, The operational fault is the actual airflow rate (m). air One or more of the following are not met: the average unit voltage of the fuel cell stack is lower than the preset value, or the cathode inlet pressure of the fuel cell stack is not up to standard.

4. The method for identifying the degree of clogging of an air filter in a hydrogen fuel cell system according to claim 1, characterized in that, The actual air compressor speed NC under the current operating ambient temperature T1 is converted into the calibrated air compressor speed NC under the calibration temperature T0 using a temperature compensation model. 补偿 This eliminates the influence of temperature on speed determination. Specific steps: Air compressor speeds under the same operating conditions were collected at different ambient temperatures. A temperature compensation model was established to reflect the relationship between ambient temperature and air compressor speed changes. This temperature compensation model is expressed as: NC 补偿 =NC* Wherein, the units of the calibration temperature T0 and the current ambient temperature T1 are K, NC 补偿 To calibrate the air compressor speed; The actual air compressor speed NC and the current operating ambient temperature T1, collected in real time, are substituted into the temperature compensation model to calculate the calibrated air compressor speed NC. 补偿 .

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