A fuel cell water balance adaptive control method and system

Abstract

The application discloses a fuel cell water balance self-adaptive control method and system, comprising the following steps: calculating the stack attenuation state based on the obtained stack operation condition parameters; judging the corresponding operation condition parameter group matched with the stack attenuation state based on the calculation; generating and sending a control operation parameter instruction; and adjusting the air state delivered into the stack according to the operation parameter instruction. The application can ensure that the stack is always in the most suitable humidity range under the current attenuation state, and the gas delivered into the stack can meet the most suitable water balance parameter state, thereby solving the problem of membrane flooding or dryness in the stack caused by water balance disorder of the stack, and effectively improving the operation stability of the membrane electrode and the service life of the stack.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to an adaptive control method and system for fuel cell water balance. Background Technology

[0002] A fuel cell is an electrochemical device that directly converts the chemical energy of fuel into electrical energy. Its working principle is to achieve energy conversion through electrochemical reactions by using hydrogen, methanol, natural gas, etc. as fuel and oxygen or air as oxidant, with the synergistic effect of the anode, cathode and electrolyte. This process does not require combustion, so it has advantages such as high energy conversion efficiency, clean emissions and low noise.

[0003] During the operation of a fuel cell stack, its internal water balance is difficult to accurately characterize using intuitive quantitative indicators, leading to deviations in operating conditions and parameters during the stack testing phase. In existing technologies, fuel cell systems are often matched with only one set of fixed technical parameters and used until the end of the stack's lifespan. However, as the stack's operating time increases and its performance gradually declines, the heat generated by the stack increases accordingly. At this point, a single fixed system parameter will be unable to adapt to the dynamically changing hydration requirements of the membrane electrode assembly (MEA), leading to abnormal states such as MEA dryness or flooding within the stack, causing irreversible damage to the stack's structural integrity and operational stability. When using impedance methods to monitor the water content within the stack, the monitoring results are prone to deviation due to objective factors such as the measurement accuracy deviation of impedance detection equipment and the performance consistency differences between individual stack units. Similarly, it cannot accurately match the actual hydration requirements of the MEA, ultimately leading to problems such as the stack becoming dry or flooded, deviating from the expected stable operation target. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing an adaptive control method and system for fuel cell water balance.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a fuel cell water balance adaptive control method, comprising: The stack degradation state is calculated based on the acquired stack operating parameters; Based on the calculated stack attenuation state, a set of corresponding operating parameters is matched, and control operating parameter commands are generated and sent. Adjust the air condition supplied to the fuel cell stack according to the operating parameter instructions.

[0006] In some embodiments, the stack operating parameters include the initial average single-cell voltage V. 初始OCV and the current average single-chip voltage V 当前OCV The formula for calculating the stack decay state is De=(V 初始OCV -V当前OCV ) / V 初始OCV *100%.

[0007] In some embodiments, the set of operating parameters includes a set of humidity adaptation ranges and multiple sets of water balance parameters under different attenuation states obtained through calibration.

[0008] In some embodiments, the set of humidity adaptation ranges under different attenuation states is obtained through systematic testing at the fuel cell stack level, including: Start the fuel cell stack according to the preset operating conditions and monitor the operating parameters of the fuel cell stack. Continuously adjust the humidity when the fuel cell stack is in a stable operating period. When the current average single-cell voltage drop rate of the fuel cell stack exceeds the roll-off threshold, humidity adjustment is stopped and the current humidity range is recorded to calibrate and obtain a set of humidity adaptation ranges under different attenuation states.

[0009] In some embodiments, the water balance parameters include water balance temperature, water balance pressure, and water balance flow rate.

[0010] In some embodiments, the multiple sets of water balance parameters under different decay states are obtained through water balance experiments adapted to the fuel cell stack at the system level, including: Start the fuel cell stack according to the preset fuel cell stack operating conditions and monitor the fuel cell stack operating condition parameters. When the fuel cell stack is in a stable operating period, adjust the humidity to be within the humidity adaptation range. When the current water balance parameter of the fuel cell stack is at its optimal value, the fuel cell stack operation is stopped and the current water balance parameter is recorded in order to calibrate and obtain multiple sets of water balance parameters under different decay states.

[0011] In a second aspect, the present invention also provides a fuel cell water balance adaptive control system, executed via the fuel cell water balance adaptive control method as described in the first aspect, the control method comprising the following steps: The controller, electrically connected to the sensor group, is used to acquire the operating condition parameters of the fuel cell stack, calculate the fuel cell stack decay state and match the humidity adaptation range and water balance parameter group corresponding to the current fuel cell stack decay state, as well as generate and send control operation parameters. The humidifier, intercooler, and air compressor are electrically connected to the controller to acquire control operating parameters and adjust the state of the air supplied to the fuel cell stack.

[0012] In some embodiments, the humidifier air inlet is connected to the intercooler and the fuel cell stack air outlet through pipelines, and the humidifier air outlet is connected to the air outlet and the fuel cell stack air inlet through pipelines.

[0013] In some embodiments, the intercooler inlet is connected to the air compressor via a pipeline, and the air compressor is connected to the intake end via a pipeline.

[0014] In some embodiments, the sensor group includes a flow sensor, a pressure sensor, a temperature sensor, and a humidity sensor. The flow sensor is disposed on the pipeline connecting the humidifier and the air inlet, and the pressure sensor, temperature sensor, and humidity sensor are disposed on the pipeline connecting the humidifier and the fuel cell stack air inlet.

[0015] The present invention has the following beneficial effects: This invention calculates the fuel cell stack decay state based on acquired fuel cell stack operating condition parameters. Then, based on the calculated fuel cell stack decay state, it determines and matches the corresponding operating condition parameter set, and generates and sends control operating parameters to adjust the air state supplied to the fuel cell stack. This ensures that the fuel cell stack is always within the most suitable humidity range under the current decay state, and that the gas supplied to the fuel cell stack meets the optimal water balance parameter state. This solves the problem of water flooding or dryness of the internal membrane due to water balance imbalance in the fuel cell stack, effectively improving the operational stability of the membrane electrode and the service life of the fuel cell stack. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the adaptive control method for fuel cell water balance proposed in this invention. Figure 1 ; Figure 2 This is a flowchart illustrating the adaptive control method for fuel cell water balance proposed in this invention. Figure 2 ; Figure 3 This is a flowchart illustrating the adaptive control method for fuel cell water balance proposed in this invention. Figure 3 ; Figure 4 This is a schematic diagram of the fuel cell water balance adaptive control system proposed in this invention.

[0017] Legend: 1. Controller; 2. Humidifier; 3. Intercooler; 4. Air compressor; 5. Fuel cell stack; 6. Flow sensor; 7. Pressure sensor; 8. Temperature sensor; 9. Humidity sensor. Detailed Implementation

[0018] 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.

[0019] This application provides a fuel cell water balance adaptive control method and system, which solves the problem in the prior art that it is difficult to adapt to the dynamic changes in the hydration requirements of the membrane electrode assembly (MEA), leading to abnormal states such as dryness or flooding of the MEA inside the fuel cell stack, causing irreversible damage to the structural integrity and operational stability of the stack. This application ensures that the fuel cell stack is always within the most suitable humidity range for its current degradation state, and that the gas supplied to the stack meets the optimal water balance parameters, thus solving the problem of water flooding or dryness of the membrane electrode assembly due to water balance imbalance, effectively improving the operational stability of the MEA and the service life of the fuel cell stack.

[0020] Please refer to the following examples for details: Reference Figures 1-3 An embodiment of the adaptive control method for fuel cell water balance provided by the present invention includes the following specific structure: S100, calculate the degradation state of fuel cell 5 based on the obtained operating parameters of fuel cell 5; S200, based on the calculated attenuation state of the fuel cell stack 5, matches the corresponding operating parameter group, and generates and sends control operating parameter commands; S300 adjusts the air state supplied to fuel cell stack 5 according to operating parameter instructions.

[0021] For example, the current decay state of the fuel cell stack 5 is calculated based on the real-time operating condition parameters of the fuel cell stack 5 collected by the sensor group; then, according to the calculated decay state of the fuel cell stack 5, the pre-calibrated operating condition parameter group is retrieved and the corresponding operating condition parameter group is determined; then, control operating parameter control commands are generated and sent, thereby adjusting the air state parameters delivered to the inside of the fuel cell stack 5 to ensure that the water balance inside the fuel cell stack 5 matches the hydration requirements of the membrane electrode.

[0022] For example, the operating parameters of the fuel cell stack 5 include the initial average cell voltage Vinitial OCV and the current average cell voltage Vcurrent OCV. Correspondingly, the formula for calculating the decay state of fuel cell stack 5 is De=(V 初始OCV -V 当前OCV ) / V 初始OCV *100%.

[0023] It should be noted that the operating parameter set includes a set of humidity adaptation ranges RH[α1, α2] obtained from calibration under different attenuation states, and multiple sets of water balance parameters [T]. i P i Q i ]; where α1 is the minimum humidity threshold for maintaining hydration of the membrane electrode under this decay state, α2 is the maximum humidity threshold for avoiding flooding, and T i To adapt to the air temperature parameters, P iTo adapt the air pressure parameters, Q i The appropriate airflow parameters.

[0024] In some embodiments, a set of humidity adaptation ranges under different attenuation states is obtained through systematic testing of the fuel cell stack at 5 levels. The specific calibration steps include: Start the fuel cell 5 according to the preset operating conditions and monitor the operating parameters RH[α1, α2] of the fuel cell 5. Continuously adjust the humidity when the fuel cell 5 is in a stable operating period. When the current average single-cell voltage drop rate of fuel cell stack 5 exceeds the roll-off threshold, humidity adjustment is stopped and the current humidity range is recorded in order to calibrate and obtain a set of humidity adaptation ranges under different attenuation states.

[0025] For example, the fuel cell stack 5 is first started according to the preset typical operating conditions of the fuel cell stack 5, and the voltage, current, temperature and air intake humidity of the fuel cell stack 5 are monitored in real time through the sensor group. Then, after the operating state of the fuel cell stack 5 reaches a stable period, the air intake humidity is gradually adjusted in a preset step size. Then, the change trend of the current average single-cell voltage of the fuel cell stack 5 is monitored in real time. When the voltage drop rate exceeds the preset roll-off threshold, the humidity adjustment operation is stopped immediately, and the upper and lower limits of humidity at this time are recorded as the humidity adaptation range RH[α1, α2] under this decay state. The above steps are repeated to complete the calibration of the humidity adaptation range under different decay states throughout the entire life cycle of the fuel cell stack 5.

[0026] In some embodiments, the water balance parameters include the water balance temperature value T, the water balance pressure value P, and the water balance flow rate value Q; while multiple sets of water balance parameters [T] under different decay states i P i Q i The calibration was obtained through a water balance experiment of the adaptive fuel cell stack 5 at the system level. The specific calibration steps included: Start the fuel cell stack 5 according to the preset operating conditions and monitor the operating parameters of the fuel cell stack 5. When the fuel cell stack 5 is in a stable operating period, adjust the humidity to the humidity adaptation range RH[α1, α2]. When the current water balance parameter of fuel cell stack 5 is at its optimal value, stop the operation of fuel cell stack 5 and record the current water balance parameter to calibrate and obtain multiple sets of water balance parameters under different decay states [T]. i P i Q i ].

[0027] For example, firstly, the fuel cell stack 5 is started according to the preset typical operating conditions, and the voltage, current, and temperature parameters of the fuel cell stack 5 are collected and monitored in real time through the sensor group; then, after the fuel cell stack 5 enters the stable operating period, the intake air humidity is adjusted to the calibrated humidity adaptation range RH[α1, α2] under the decay state; then, the intake air temperature, pressure, and flow parameters are adjusted in sequence, and the output efficiency and voltage stability of the fuel cell stack 5 are monitored in real time. When the fuel cell stack 5 is in the optimal operating state with the highest output efficiency and the smallest voltage fluctuation, the temperature, pressure, and flow parameters at this time are determined to be the optimal water balance parameters under the decay state and humidity conditions; the operation of the fuel cell stack 5 is stopped and the current optimal water balance parameters are recorded, thus completing a set of [T i P i Q i Calibration of parameters; repeat the above steps to complete the calibration of multiple sets of water balance parameters under different attenuation states and humidity adaptation ranges.

[0028] Understandably, after the process is started, a systematic test of the fuel cell stack 5 levels is carried out first. Through this test, the humidity adaptation range corresponding to different fuel cell stack 5 degradation states is obtained. For example: 0% degradation is adapted to [50%, 80%], 5% degradation is adapted to [60%, 85%], 10% degradation is adapted to [70%, 90%], 15% degradation is adapted to [75%, 95%], and 20% degradation is adapted to [80%, >95%]; Subsequently, a system-level water balance adaptation experiment of fuel cell stack 5 was conducted. The optimal water balance system parameter group was determined for different fuel cell stack 5 attenuation states. For example: 0% attenuation corresponds to parameter group 1 [T1, P1, Q1], 5% attenuation corresponds to parameter group 2 [T2, P2, Q2], 10% attenuation corresponds to parameter group 3 [T3, P3, Q3], 15% attenuation corresponds to parameter group 4 [T4, P4, Q4], and 20% attenuation corresponds to parameter group 5 [T5, P5, Q5]. Finally, based on the real-time calculated decay state of fuel cell stack 5, the corresponding operating parameter group is determined and matched, and then the corresponding control operating parameters are generated and sent.

[0029] Reference Figures 1-4 The present invention also provides an embodiment of a fuel cell water balance adaptive control system for operating the fuel cell water balance adaptive control method described in the above embodiments. The control system includes: Controller 1 is electrically connected to the sensor group and is used to acquire the operating condition parameters of the fuel cell stack 5 collected by the sensor group. Based on the preset attenuation rate calculation formula, it completes the quantitative calculation of the attenuation state of the fuel cell stack 5, retrieves the pre-stored operating condition parameter group and matches the humidity adaptation range and water balance parameters that are compatible with the current attenuation state, and finally generates and sends the corresponding control operating parameters to each actuator. In some embodiments, the air inlet of the humidifier 2 is connected to the air outlet of the intercooler 3 and the air outlet of the fuel cell stack 5 through pipelines, which can realize the mixing and humidification of the wet exhaust gas discharged from the fuel cell stack 5 and the cold air transported by the intercooler 3; the air outlet of the humidifier 2 is connected to the air outlet of the system and the air inlet of the fuel cell stack 5 through pipelines, which can transport the air adjusted to the target humidity to the fuel cell stack 5 to participate in the electrochemical reaction.

[0030] In some embodiments, the air inlet of the intercooler 3 is connected to the air compressor 4 via a pipeline to cool the high-temperature air compressed by the air compressor 4, so that its temperature reaches a preset water balance temperature value; correspondingly, the air compressor 4 is connected to the air inlet via a pipeline to draw outside air into the system and compress it to a preset pressure range.

[0031] In some embodiments, the sensor group includes a flow sensor 6, a pressure sensor 7, a temperature sensor 8, and a humidity sensor 9; wherein, the flow sensor 6 is disposed on the pipeline connecting the humidifier 2 and the system air inlet, and is used to monitor the air flow rate entering the humidifier 2 in real time; the pressure sensor 7, the temperature sensor 8, and the humidity sensor 9 are disposed on the pipeline connecting the humidifier 2 and the fuel cell stack 5 air inlet, and are used to monitor the air pressure, temperature, and humidity parameters delivered to the fuel cell stack 5 in real time, respectively.

[0032] In some embodiments, the humidifier 2, intercooler 3, and air compressor 4, which are actuators, are all electrically connected to the controller 1. By receiving control operation parameter instructions sent by the controller 1, they respectively adjust the corresponding humidity, temperature, and flow rate of the air entering the fuel cell stack 5, thereby achieving precise control of the air state delivered into the fuel cell stack 5.

[0033] Working principle: First, controller 1 performs system initialization, and then reads the historical attenuation data of fuel cell stack 5; Next, the initial average single-cell open-circuit voltage VinitialOCV and the current average single-cell open-circuit voltage VcurrentOCV of the real-time acquisition stack 5 are obtained, and then calculated using the formula De = (VinitialOCV)current. 初始OCV -V 当前OCV ) / V 初始OCV *The attenuation rate of fuel cell stack 5 is calculated with 100% accuracy, and then the attenuation status is determined. Then, based on the judgment result, the corresponding water balance parameter group is matched for different attenuation states. For example: 0% attenuation corresponds to parameter group 1 [T1, P1, Q1], 5% attenuation corresponds to parameter group 2 [T2, P2, Q2], 10% attenuation corresponds to parameter group 3 [T3, P3, Q3], 15% attenuation corresponds to parameter group 4 [T4, P4, Q4], and 20% attenuation corresponds to parameter group 5 [T5, P5, Q5]. Then, parameter control operations are performed to ensure that the fuel cell stack 5 operates normally according to the matched parameters.

[0034] Through the above technical solution, this application first calculates the current degradation state of the fuel cell stack 5 accurately based on the real-time operating parameters of the fuel cell stack 5 collected by sensors and the factory benchmark parameters of the fuel cell stack 5. Then, based on the quantified degradation degree of the fuel cell stack 5, it retrieves the operating parameter group that has been calibrated in advance through the fuel cell stack 5 hierarchical system test and system hierarchical water balance adaptation experiment, generates and sends targeted control operating parameters, thereby dynamically regulating key state parameters such as air temperature, pressure, flow rate and humidity delivered into the fuel cell stack 5. It can match the optimal humidity adaptation range and water balance parameters in real time according to the differences in hydration requirements of the fuel cell stack 5 at different degradation stages, ensuring that the fuel cell stack 5 is always in the best operating environment under the current state during the degradation process. This solves the problem of water flooding or dryness of the membrane electrode in the stack caused by changes in heat generation after the fuel cell stack 5 degradation and the inability of traditional fixed parameters to adapt to the hydration requirements of the membrane electrode. It effectively avoids irreversible damage to the structure and performance of the fuel cell stack 5 under abnormal conditions, improves the operating stability and reliability of the membrane electrode, and thus effectively extends the overall service life of the fuel cell stack 5.

[0035] 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 fuel cell water balance adaptive control method, characterized in that, include: The stack degradation state is calculated based on the acquired stack operating parameters; Based on the calculated stack attenuation state, a set of corresponding operating parameters is matched, and control operating parameter commands are generated and sent. Adjust the air condition supplied to the fuel cell stack according to the operating parameter instructions.

2. The adaptive control method for fuel cell water balance according to claim 1, characterized in that, The stack operating parameters include the initial average single-cell voltage V. 初始OCV and the current average single-chip voltage V 当前OCV The formula for calculating the stack decay state is De=(V 初始OCV -V 当前OCV ) / V 初始OCV *100%.

3. The adaptive control method for fuel cell water balance according to claim 1, characterized in that, The set of operating parameters includes a set of humidity adaptation ranges and multiple sets of water balance parameters under different attenuation states obtained through calibration.

4. The adaptive control method for fuel cell water balance according to claim 3, characterized in that, The set of humidity adaptation ranges under different attenuation states was obtained through systematic testing at the fuel cell stack level, including: Start the fuel cell stack according to the preset operating conditions and monitor the operating parameters of the fuel cell stack. Continuously adjust the humidity when the fuel cell stack is in a stable operating period. When the current average single-cell voltage drop rate of the fuel cell stack exceeds the roll-off threshold, humidity adjustment is stopped and the current humidity range is recorded to calibrate and obtain a set of humidity adaptation ranges under different attenuation states.

5. The adaptive control method for fuel cell water balance according to claim 3, characterized in that, The water balance parameters include water balance temperature, water balance pressure, and water balance flow rate.

6. The adaptive control method for fuel cell water balance according to claim 3, characterized in that, The multiple sets of water balance parameters under different decay states were obtained through water balance experiments adapted to the fuel cell stack at the system level, including: Start the fuel cell stack according to the preset fuel cell stack operating conditions and monitor the fuel cell stack operating condition parameters. When the fuel cell stack is in a stable operating period, adjust the humidity to be within the humidity adaptation range. When the current water balance parameter of the fuel cell stack is at its optimal value, the fuel cell stack operation is stopped and the current water balance parameter is recorded in order to calibrate and obtain multiple sets of water balance parameters under different decay states.

7. A fuel cell water balance adaptive control system, characterized in that, The control system is used to run the fuel cell water balance adaptive control method as described in any one of claims 1 to 6, the control system comprising: The controller, electrically connected to the sensor group, is used to acquire the operating condition parameters of the fuel cell stack, calculate the fuel cell stack decay state and match the humidity adaptation range and water balance parameter group corresponding to the current fuel cell stack decay state, as well as generate and send control operation parameters. The humidifier, intercooler, and air compressor are electrically connected to the controller to acquire control operating parameters and adjust the state of the air supplied to the fuel cell stack.

8. The fuel cell water balance adaptive control system according to claim 7, characterized in that, The humidifier's air inlet is connected to the intercooler and the fuel cell stack's air outlet via pipelines, and the humidifier's air outlet is connected to the air outlet and the fuel cell stack's air inlet via pipelines.

9. The fuel cell water balance adaptive control system according to claim 7, characterized in that, The intercooler inlet is connected to the air compressor via a pipeline, and the air compressor is connected to the air intake via a pipeline.

10. The fuel cell water balance adaptive control system according to claim 7, characterized in that, The sensor group includes a flow sensor, a pressure sensor, a temperature sensor, and a humidity sensor. The flow sensor is installed on the pipeline connecting the humidifier and the air inlet, and the pressure sensor, temperature sensor, and humidity sensor are installed on the pipeline connecting the humidifier and the fuel cell stack air inlet.

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