A fuel cell health monitoring method and device based on pressure and temperature combined monitoring

Abstract

This invention relates to a method and apparatus for fuel cell health monitoring based on joint pressure and temperature monitoring. The method includes: collecting multi-point temperatures and flow channel pressures of individual cells in a fuel cell stack; using the multi-point temperatures and flow channel pressures to determine whether a fault has occurred, analyzing the fault type, and simultaneously locating the fault location; determining whether to shut down for maintenance based on the fault type and fault location; and if no shutdown for maintenance is required, taking control measures. This invention achieves accurate real-time acquisition, wireless transmission, and early fault location and warning of local multi-point temperatures and key flow channel pressures within the fuel cell stack, providing technical support for the application of fuel cells in long-term stable operation scenarios.

Description

Technical Field

[0001] This invention relates to the field of fuel cell monitoring technology, and in particular to a method and apparatus for fuel cell health monitoring based on combined pressure and temperature monitoring. Background Technology

[0002] A fuel cell is an electrochemical device that directly converts the chemical energy contained in fuel into electrical energy. Its structure is similar to that of a conventional battery, consisting primarily of positive and negative electrodes and an electrolyte. During operation, fuel and oxidant must be continuously supplied from an external source to sustain the electrochemical reaction. However, when a single fuel cell is connected to an external load, its output voltage is typically low, making it difficult to meet the voltage requirements of practical applications. Therefore, multiple single cells are usually stacked in series to form a fuel cell stack that can output a higher voltage. To further increase the voltage or current, multiple stacks can be connected in series or parallel to form a larger-scale battery array. Whether it's a single stack or a multi-stack array, real-time monitoring of its operating status is crucial to ensuring long-term stable operation.

[0003] The current mainstream method for monitoring the health status of fuel cell stacks involves collecting voltage signals from all individual cells via sensors during stack operation to assess the overall health of the stack, sub-stacks, and even individual cells. However, this method is prone to biased health status assessments due to the macroscopic nature of voltage signals. It also fails to penetrate the stack's encapsulation structure to reflect changes in core physical quantities such as internal flow channel pressure fluctuations and localized temperature unevenness, making it difficult to detect specific anomalies such as flooding, membrane drying, and membrane damage. Furthermore, while some studies have employed electrochemical impedance spectroscopy (EIS) to monitor the internal state of the stack, this method suffers from cumbersome procedures and response delays, limiting its applicability in real-time monitoring scenarios and hindering the rapid capture of dynamic changes in the stack's health status.

[0004] Existing technical solutions disclose a health diagnosis method and system for fuel cell systems. The core method involves: acquiring voltage signals from individual cells within the fuel cell stack under a preset current density set; calculating the minimum single-cell voltage and comparing it with a fault threshold, and accumulating the number of fault triggers to diagnose low single-cell voltage; calculating the average voltage of individual cells and comparing it with the initial average voltage of preset and limit ratios, and accumulating the number of alarms to diagnose stack performance degradation; defining front-end and back-end cell sets and calculating the difference between the total voltage mean square error and the mean square error of the front-end and back-end voltages to diagnose dry / humidity conditions; and feeding back the diagnostic results and voltage signals to the system controller via polling, triggering alarms or shutting down the system in case of an anomaly to ensure stable system operation. However, this technology relies solely on voltage signals as the core diagnostic tool, neglecting to consider key parameters such as pressure, temperature, and gas concentration. Different faults may cause similar voltage changes, potentially leading to misdiagnosis.

[0005] Existing technical solutions also disclose an online prediction method for the health status of proton exchange membrane fuel cells based on impedance analysis. This method achieves monitoring through a "impedance analysis-model establishment-health estimation" process. First, DRT analysis is used to perform KK verification on EIS data, converting the complex impedance into a relaxation time distribution function. Integrating the multi-peak curve yields three types of reaction impedance. Then, a linear fit between resistance and measured voltage is used to establish the relationship between the ECM degradation model and voltage. Finally, using a 5-20 hour time window and 10-hour voltage data sets as input, a hybrid neural network is used to cyclically predict future voltage and extrapolate the reaction resistance value, achieving online health status estimation. While this method uses DRT data analysis and neural network cyclic prediction of health status, it consumes considerable computational resources and is difficult to meet the real-time requirements of high-frequency online monitoring for multi-cell fuel cell stacks. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention aims to provide a fuel cell health monitoring method and device based on joint pressure and temperature monitoring, focusing on proton exchange membrane fuel cell stacks. This invention addresses the issue of coarse monitoring and difficulty in extracting intuitive status information in current real-time stack monitoring technologies. By embedding advanced ultra-thin flexible sensors into the battery electrode plates, precise real-time acquisition, wireless transmission, and early fault location and warning of localized multi-point temperatures and key flow channel pressures within the stack are achieved, providing technical support for the application of fuel cells in long-term stable operation scenarios.

[0007] To achieve the above objectives, the present invention provides the following solution: A fuel cell health monitoring method based on joint pressure and temperature monitoring includes: The temperature and flow pressure of individual cells in the fuel cell stack are collected at multiple points. The temperature and flow pressure at multiple points are used to determine whether a fault has occurred, analyze the fault type, and locate the fault location. Determine whether to shut down for maintenance based on the fault type and location. If no shutdown is required, take control measures.

[0008] Optionally, collecting multi-point temperature and flow channel pressure of individual cells in the fuel cell stack includes: Flexible pressure sensors are embedded at the inlet and outlet of the flow channels of the cathode and anode plates in the single cell to monitor pressure changes in the cathode and anode flow channels, and multiple temperature sensors are embedded on the back of the cathode plate to detect the temperature of the single cell at multiple points.

[0009] Optionally, the multi-point temperature and the flow channel pressure are used to determine whether a fault has occurred, and the fault type is analyzed, including: The multi-point temperature and the flow channel pressure are compared to determine whether any point temperature and flow channel pressure are abnormal. If abnormal, the fault type is analyzed. If not abnormal, the multi-point temperature and flow channel pressure of a single cell in the fuel cell stack are collected again for fault judgment.

[0010] Optionally, analyzing the fault type includes: When the pressure difference between the inlet and outlet of the cathode and anode channels of a single cell is greater than the upper limit of the target threshold and the temperature at any point continues to drop, it is proven that the fault is a flooding fault. When the pressure difference between the inlet and outlet of the cathode and anode channels of a single cell is less than the lower limit of the target threshold and the temperature at any point continues to rise, it is proven that the fault is a membrane dry fault. When the pressure between the inlet and outlet of the cathode and anode channels of a single cell changes abruptly and the temperature at any point changes drastically, it is proven that the fault is a membrane rupture and gas leakage.

[0011] Optionally, the control measures include: If a flooding fault occurs in a localized cell that is not exceeding the target number, the anode three-way valve and cathode three-way valve will be activated to perform a pulse-type purging on the flow channel corresponding to the flooded cell. This involves increasing the opening of the hydrogen or oxygen regulating valve on the side corresponding to the faulty flow channel to increase the air intake flow rate, while simultaneously slightly opening the corresponding anode or cathode back pressure valve to reduce the back pressure in the flow channel. This creates a momentary high-flow-rate purging and drainage process. During the purging process, the humidification power of the corresponding anode or cathode humidifier will be reduced simultaneously to temporarily lower the relative humidity of the intake air until the monitoring parameters corresponding to the localized cell return to the normal range. After this, the purging will stop and the rated air supply will be restored. If more than the target number of individual cells experience flooding, then the entire stack will be coordinated to drain water. Simultaneously, the opening of the hydrogen and oxygen regulating valves will be increased to improve the overall anode and cathode airflow. The anode and cathode back pressure valves will be adjusted to increase the gas flow rate in the flow channels while maintaining stable internal pressure. The humidification capacity of the anode and cathode humidifiers will be reduced to lower the relative humidity of the intake air. At the same time, the coolant circulation pump flow rate will be reduced. In conjunction with the heat exchanger and fan, the stack operating temperature will be slightly increased to accelerate the evaporation of liquid water. Once the monitoring parameters corresponding to the individual cells of the entire stack return to the normal range, the rated operating parameters will be gradually restored.

[0012] Optionally, the aforementioned control measures may also include: If a localized cell experiences membrane dryness failure (not exceeding the target number), the anode or cathode humidifier on the corresponding side of the faulty flow channel will be activated to temporarily increase humidification power. Simultaneously, the opening of the corresponding hydrogen or oxygen regulating valve will be slightly reduced to decrease gas flow rate and extend the residence time of humidified gas, thereby enhancing the proton exchange membrane hydration effect. The fan speed will be slightly increased to decrease the coolant return water temperature, bringing the stack operating temperature back to the lower limit of the rated range. This process will continue until the monitoring parameters corresponding to the localized cell return to the normal range, at which point the rated operating parameters will be gradually restored. If a localized cell experiences membrane dryness failure (exceeding the target number), the humidification power of the anode and cathode humidifiers will be increased to relatively increase the humidity of the anode and cathode intake air. The hydrogen and oxygen regulating valves will be adjusted simultaneously to slightly reduce the overall stack intake air flow rate, extending the residence time of humidified gas and enhancing the overall proton exchange membrane hydration effect. At the same time, the fan speed will be increased and the coolant circulation pump flow rate will be adjusted to stabilize the stack operating temperature within the rated operating temperature range. This process will continue until the monitoring parameters corresponding to the entire stack's cells return to the normal range, at which point the rated operating parameters will be gradually restored.

[0013] Optionally, the aforementioned control measures may also include: If the inlet and outlet pressures of the cathode and anode channels of a single cell suddenly change abnormally to less than the first target value and the temperature at any point suddenly changes to less than the second target value, and there is no hydrogen leak alarm, then the stack output operating current is reduced to the target rated current, and the anode back pressure valve and cathode back pressure valve are adjusted synchronously to control the anode-cathode pressure difference within the target range to suppress the escalation of the fault. At the same time, the pressure, temperature of the faulty single cell and the hydrogen leak concentration of the entire stack are monitored. If the parameters continue to deteriorate, a shutdown maintenance is immediately triggered. If the inlet and outlet pressures of the cathode and anode channels of a single cell suddenly change abnormally to greater than the first target value and the temperature at any point suddenly changes to greater than the second target value, or a hydrogen leak alarm is triggered, then a shutdown maintenance is immediately performed, that is, the stack load is completely unloaded, the hydrogen regulating valve and oxygen regulating valve are closed synchronously to cut off the supply of hydrogen and oxygen, and then the anode back pressure valve and cathode back pressure valve are fully opened to safely vent the residual gas in the stack. At the same time, the location information of the faulty single cell is uploaded and locked for storage.

[0014] Optionally, the aforementioned control measures may also include: The operating current is obtained, and the gas supply flow rate and pressure are adjusted based on the demand of the operating current, that is, the opening of the inlet valve is increased to increase the gas supply, and the opening of the back pressure valve is decreased to increase the gas pressure.

[0015] To achieve the above objectives, the present invention also provides a fuel cell health monitoring device based on joint pressure and temperature monitoring, comprising: The data acquisition module is used to collect multi-point temperature and flow channel pressure of individual cells in the fuel cell stack; The monitoring module is used to determine whether a fault has occurred by using the multi-point temperature and the flow channel pressure, analyze the fault type, and locate the fault location. The main control module is used to determine whether to stop the machine for maintenance based on the fault type and the fault location. If no shutdown for maintenance is required, control measures are taken.

[0016] The beneficial effects of this invention are as follows: This invention utilizes the miniaturization, high sensitivity, and wireless transmission characteristics of advanced flexible sensors, embedding them in specific locations on the battery plates to achieve real-time and accurate acquisition of inlet and outlet pressures of the internal flow channels and local multi-point temperatures of the electrodes, thus intuitively extracting dynamic operating status information inside the battery stack.

[0017] This invention achieves early warning and precise location of abnormal faults through multi-parameter collaborative analysis, providing data support for the maintenance and optimization of fuel cell stacks, and ultimately improving the reliability and durability of fuel cells in long-term stable operation scenarios.

[0018] In summary, this invention breaks through the bottleneck of traditional monitoring technology, which can only make macroscopic judgments. It penetrates the fuel cell stack packaging structure and reflects changes in core physical quantities such as internal flow channel pressure and local temperature, thus reflecting abnormalities such as flooding, membrane drying, and membrane damage and breakage. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a fuel cell health monitoring device based on joint monitoring of pressure and temperature, according to an embodiment of the present invention. Figure 2 This is a diagram showing the arrangement of fuel cell electrode sensors according to an embodiment of the present invention; Figure 3 This is a flowchart of a fuel cell health monitoring method based on joint pressure and temperature monitoring according to an embodiment of the present invention; The components include: hydrogen source-1, oxygen source-2, hydrogen regulating valve-3, oxygen regulating valve-4, anode three-way valve-5, cathode three-way valve-6, anode humidifier-7, cathode humidifier-8, status monitoring platform-9, main control module-10, anode back pressure valve-11, cathode back pressure valve-12, coolant circulation pump-13, coolant tank-14, cooling circulation three-way valve-15, heat exchanger-16, fan-17, cathode electrode plate-1021, cathode flow channel-1022, and anode flow channel-10. 23, Proton Exchange Membrane Fuel Cell Stack-100, Pressure Sensor-101, Single Cell-102, Temperature Sensor-103, Single Cell Cathode Channel Inlet Pressure Sensor-1011, Single Cell Cathode Channel Outlet Pressure Sensor-1012, Single Cell Anode Channel Inlet Pressure Sensor-1011', Single Cell Anode Channel Outlet Pressure Sensor-1012', Upper Electrode Temperature Sensor-1031, Middle Electrode Temperature Sensor-1032, Lower Electrode Temperature Sensor-1033. Detailed Implementation

[0020] 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.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, this embodiment discloses a fuel cell health monitoring device based on joint monitoring of pressure and temperature. The structure is described below. The device mainly consists of six parts: a gas supply module, a fuel cell stack module, a status monitoring module, a cooling circulation module, and a control module. The modules are connected by pipes and wires to form a complete gas circulation and signal transmission link.

[0023] The proton exchange membrane fuel cell stack 100 comprises a pressure sensor 101, a single cell 102, and a temperature sensor 103. The pressure sensor 101 and temperature sensor 103 are thin-film strain sensors from Minggan Technology, embedded within the cell. Components include: hydrogen source 1, oxygen source 2, hydrogen regulating valve 3, oxygen regulating valve 4, anode three-way valve 5, cathode three-way valve 6, anode humidifier 7, cathode humidifier 8, condition monitoring platform 9, main control module 10, anode back pressure valve 11, cathode back pressure valve 12, coolant circulation pump 13, coolant tank 14, cooling circulation three-way valve 15, heat exchanger 16, fan 17, cathode electrode plate-1021, cathode flow channel-1022, anode flow channel-1023, flow channel inlet pressure sensor 1011, flow channel outlet pressure sensor 1012, upper electrode temperature sensor 1031, middle electrode temperature sensor 1032, and lower electrode temperature sensor 1033.

[0024] The gas supply module controls the hydrogen flow rate via hydrogen regulating valve 3, supplying hydrogen from hydrogen source 1 to fuel cell stack 100 via pipeline to provide fuel for the anodic oxidation reaction. Anode three-way valve 6 controls the gas flow rate through anode humidifier 7 by adjusting its opening, achieving different humidification levels to meet the anode's intake humidity requirements. Humidified hydrogen mixes with dry hydrogen in the pipeline before finally flowing into the fuel cell anode channel. Excess hydrogen in the anode channel is discharged from the battery system via anode back pressure valve 11 after back pressure adjustment. Oxygen source 2 stores high-pressure oxygen, and its flow rate is controlled by oxygen regulating valve 4, supplying oxygen to fuel cell stack 100 via pipeline to provide oxidant for the cathode reduction reaction. Cathode three-way valve 5 controls the gas flow rate through cathode humidifier 8 by adjusting its opening, achieving different humidification levels to meet the cathode's intake humidity requirements. Humidified oxygen mixes with dry oxygen in the pipeline before finally flowing into the fuel cell cathode channel. Excess oxygen and water generated in the cathode channel are discharged from the battery system through the cathode back pressure valve 12 via a pipeline.

[0025] The cooling circulation module consists of a coolant circulation pump 13, a cooling water tank 14, a three-way valve 15, a heat exchanger 16, a fan 17, and related piping. The outlet of the cooling water tank 14 is connected to the coolant circulation pump 13. The pumped coolant is diverted through the cooling circulation three-way valve 15 into the heat exchanger 16, cooled by the fan 17, and then pumped into the fuel cell stack module for heat exchange. The high-temperature coolant after heat exchange returns to the cooling water tank 14 through the coolant outlet pipe, forming a closed-loop circulation. The circulation pump flow rate, fan speed, and three-way valve opening can be adjusted by the main control module 10 according to the temperature signal to control the operating temperature of the fuel cell stack.

[0026] The fuel cell stack 100 is composed of multiple stacked single cells 102. It converts incoming hydrogen and oxygen into water and heat, achieving the conversion of chemical energy into electrical energy. On the back of the cathode electrode plate 1021 of each single cell, a temperature sensor 1031 (upper electrode), a temperature sensor 1032 (middle electrode), and a temperature sensor 1033 (lower electrode) are implanted. At the inlet and outlet positions of the cathode flow channel 1022, a single cell cathode flow channel inlet pressure sensor 1011 and a single cell cathode flow channel outlet pressure sensor 1012 are implanted, respectively. Similarly, at the inlet and outlet positions of the anode flow channel 1023, a single cell anode flow channel inlet pressure sensor 1011' and a single cell anode flow channel outlet pressure sensor 1012' are implanted, respectively. All sensors are pre-assigned unique physical addresses corresponding one-to-one with the stack sequence number of the single cell. That is, all pressure sensors 101 and temperature sensors 103 of the nth single cell are bound to a unique address code of number n, achieving a one-to-one mapping between sensor data and the position of the single cell 102. Real-time collection of multi-point temperature and gas pressure data for each individual battery cell, and synchronous transmission of the address-encoded temperature and pressure data to the battery health monitoring platform via wireless transmission.

[0027] Monitoring platform 9 receives monitoring signals from temperature sensor 101 and pressure sensor 103 with address codes. It compares the real-time monitoring data of each individual battery with pre-stored normal operating threshold ranges under the same conditions. When the data for a battery corresponding to a certain address code exceeds the threshold range, the platform directly matches the address code with the corresponding battery stack number to pinpoint the location of the abnormal battery. Simultaneously, it can determine the location of abnormal areas by analyzing the distribution of abnormal data from multiple consecutive batteries. When identifying fault types, monitoring platform 9 uses the pressure difference Δ between the inlet and outlet of the battery flow channel. P The combined characteristics of multiple temperature points are used as the sole core basis for fault identification, and a single temperature or pressure parameter is not used as an independent judgment standard to avoid misjudgment. After the monitoring platform 9 identifies the fault type, it links the main control module 10 and corresponding components to execute targeted control measures.

[0028] (1) Flooding fault (judgment basis: single cell flow channel Δ P >Δ P Upper limit, corresponding to the temperature of the area T (Synchronous descent).

[0029] Localized single-cell flooding: When the parameters of a single cell or a few single cells are abnormal while the rest of the single cells are operating normally, the main control module 10, in conjunction with the anode three-way valve 5 and the cathode three-way valve 6, performs pulse-type purging on the flow channel corresponding to the faulty single cell: increasing the opening of the hydrogen regulating valve 3 or oxygen regulating valve 4 on the side corresponding to the faulty flow channel, increasing the air intake flow by 20%~50%, and simultaneously slightly opening the corresponding anode back pressure valve 11 or cathode back pressure valve 12 to reduce the back pressure of the flow channel, forming an instantaneous large-flow purging and drainage; the purging parameters are 3~5 times, each purging lasts 2~5 seconds, with a cycle interval of 10 seconds; during the purging process, the humidification power of the corresponding anode humidifier 7 or cathode humidifier 8 is simultaneously reduced, and the relative humidity of the intake air is temporarily reduced to below 50%; the Δ of the faulty single cell is monitored in real time. P With temperature T Once the parameters return to the normal range, stop purging and restore the rated gas supply parameters.

[0030] Systemic flooding of the entire reactor: When more than 60% of the individual cells exhibit abnormal parameters, the main control module 10 executes coordinated flooding control across the entire reactor; simultaneously increasing the opening of hydrogen regulating valve 3 and oxygen regulating valve 4 to increase the overall reactor anode and cathode intake airflow by 30%~80%, and simultaneously adjusting anode back pressure valve 11 and cathode back pressure valve 12 to increase the flow channel gas velocity while maintaining stable reactor pressure; simultaneously reducing the humidification capacity of anode humidifier 7 and cathode humidifier 8 to lower the relative humidity of the intake air to below 40%; simultaneously linking the cooling circulation module to reduce the flow rate of coolant circulation pump 13, and cooperating with heat exchanger 16 and fan 17 to slightly increase the reactor stack operating temperature by 2~5℃, accelerating liquid water evaporation; when the overall reactor single cell Δ P ,temperature T After returning to the normal range, gradually restore the rated operating parameters.

[0031] (2) Membrane dry failure (judgment basis: single cell flow channel pressure difference Δ P Less than Δ P The lower limit, and the corresponding regional temperature T (Synchronous increase).

[0032] Localized Single-Cell Membrane Drying: When the parameters of a single cell or a few single cells are abnormal while the rest of the single cells are operating normally, the main control module 10 will activate the anode humidifier 7 or cathode humidifier 8 on the corresponding side of the faulty flow channel to briefly increase the humidification power, raising the relative humidity of the intake air to 80%~100%; at the same time, it will slightly reduce the opening of the corresponding hydrogen regulating valve 3 or oxygen regulating valve 4 to reduce the gas flow rate and prolong the residence time of the humid gas, thereby enhancing the hydration effect of the proton exchange membrane; it will also activate the cooling circulation module to slightly increase the speed of fan 17, reduce the coolant return water temperature, and bring the stack operating temperature back to the lower limit of the rated range; and it will monitor the Δ of the faulty single cell in real time. P After the temperature and other parameters return to the normal range, gradually restore the rated operating parameters.

[0033] Systemic membrane dryness across the entire stack: When more than 60% of individual cells exhibit abnormal parameters, the main control module 10 executes coordinated humidification control across the entire stack: simultaneously increasing the humidification power of the anode humidifier 7 and cathode humidifier 8 to raise the relative humidity of the anode and cathode intake air to 90%~100%; simultaneously adjusting the hydrogen regulating valve 3 and oxygen regulating valve 4 to slightly reduce the overall intake air flow rate, prolonging the residence time of humid gas and enhancing the hydration effect of the entire stack proton exchange membrane; and simultaneously linking the cooling circulation module to increase the speed of fan 17 and adjust the flow rate of coolant circulation pump 13 to stabilize the stack operating temperature within the rated operating temperature ±2℃ range; until the overall stack single cell Δ P ,temperature T After returning to the normal range, gradually restore the rated operating parameters.

[0034] (3) Membrane rupture and gas leakage fault (judgment basis: pressure difference Δ in single cell flow channel) P An abnormal mutation occurred, and the temperature in the corresponding region... T (A sudden change occurred).

[0035] Slight gas leakage condition: When a single cell Δ P When the sudden change is less than 30%, the temperature change is less than 5°C, and there is no hydrogen leakage alarm, the main control module 10 immediately performs load reduction operation, reducing the stack output operating current to less than 30% of the rated current; synchronously adjusts the anode back pressure valve 11 and the cathode back pressure valve 12 to control the anode-cathode pressure difference within 5 kPa to suppress the escalation of the fault; at the same time, it monitors the pressure and temperature of the faulty single cell and the hydrogen leakage concentration of the entire stack in real time. If the parameters continue to deteriorate, it immediately triggers the emergency shutdown procedure.

[0036] Severe gas leakage condition: When a single cell Δ P When the sudden change is greater than 50%, the temperature change is greater than 10°C, or a hydrogen leak alarm is triggered, the main control module 10 immediately executes the emergency shutdown procedure: first, completely unload the stack load, and simultaneously close the hydrogen regulating valve 3 and the oxygen regulating valve 4 to cut off the gas supply from the hydrogen source 1 and the oxygen source 2; then, fully open the anode back pressure valve 11 and the cathode back pressure valve 12 to safely vent the residual gas in the stack; at the same time, upload the location information of the faulty single cell to the monitoring platform 9 and lock it for storage, providing a basis for subsequent maintenance.

[0037] The main control module 10 has a pre-stored working current-gas supply parameter mapping table based on the fuel cell stack polarization curve and rated operating condition calibration. This table includes core parameters such as the anode / cathode gas stoichiometry ratio, rated inlet pressure, valve opening reference value, and safe differential pressure threshold under different working currents. The main control module 10 then adjusts the working current... I To meet the needs of precise regulation of gas supply flow and pressure.

[0038] Gas flow control logic: When receiving operating current IWhen setting requirements, the main control module 10 first uses Faraday's law, combined with the number of single cells in the fuel cell stack. N Calculate the theoretical gas consumption under the current current: Theoretical mass flow rate of hydrogen at the anode: ; Theoretical mass flow rate of oxygen at the cathode: ; in, MH2 The molar mass of hydrogen gas is... MO2 The molar mass of oxygen F is Faraday's constant.

[0039] Based on the theoretical consumption and the rated stoichiometry specified in the mapping table (rated stoichiometry of hydrogen at the anode: 1.2~1.5, rated stoichiometry of oxygen at the cathode: 2.0~2.5, which can be dynamically adjusted according to operating conditions), the actual required intake flow rate is calculated. QH2, actual , QO2, actual The main control module 10 adjusts the opening of the hydrogen regulating valve 3 and the oxygen regulating valve 4 according to the calculation results, and simultaneously controls the opening and closing of the bypass branch through the anode three-way valve 5 and the cathode three-way valve 6, so as to precisely control the flow rate of hydrogen and oxygen entering the stack and match the electrochemical reaction requirements of the current working current.

[0040] (1) When the working current increases, increase the opening of the inlet valve to increase the gas supply flow rate and meet the reaction requirements under high load; (2) When the working current decreases, reduce the opening of the intake valve and reduce the gas supply flow rate to avoid problems such as water flooding of the flow channel and waste of hydrogen caused by excessive gas supply.

[0041] Gas pressure regulation logic: The main control module 10 regulates the gas pressure according to the current operating current. I The corresponding rated internal pressure range in the matching mapping table (low pressure range for low current operation and high pressure range for high current operation) is used to precisely control the back pressure of the anode and cathode flow channels of the fuel cell stack by adjusting the opening of the anode back pressure valve 11 and the cathode back pressure valve 12, so as to maintain the internal pressure within the corresponding range.

[0042] (1) When the operating current increases, reduce the opening of the back pressure valve to increase the gas pressure inside the reactor, enhance the electrochemical reaction rate, and reduce concentration polarization under high load. (2) When the operating current decreases, increase the opening of the back pressure valve to reduce the gas pressure inside the reactor, reduce the mechanical stress of gas permeation and proton exchange membrane, and extend the service life of the membrane.

[0043] During pressure regulation, the main control module 10 always maintains the pressure difference between the anode and cathode within the preset safety threshold (usually ≤10kPa) to avoid excessive pressure difference causing mechanical damage to the proton exchange membrane. At the same time, it synchronously receives real-time pressure and temperature data from the monitoring platform 9. If abnormal parameters occur during regulation, the parameter regulation is immediately suspended, and the corresponding fault handling logic is executed first to ensure the safe operation of the fuel cell stack.

[0044] like Figure 2 As shown, pressure sensors 1011-1012 and 1011'-1012' are embedded in the inlet and outlet of the flow channel of the single cell's cathode / anode plate, respectively. The embedded pressure sensors are flexible pressure-sensitive sensors from Minggan Technology Co., Ltd., with a thickness ≤0.3mm, a pressure-sensitive area diameter ≤6mm, a pressure measurement range covering the working gas pressure, and a linearity ≥0.98. They are used to monitor pressure changes in the cathode and anode flow channels, monitor gas blockage in the flow channels by reflecting the pressure difference between the inlet and outlet of the cathode / anode flow channels, collect and transmit pressure fluctuations for different faults, such as flooding, membrane rupture, and gas leakage, and can determine the location of the faulty single cell. Temperature sensors 1031, 1032, and 1033 are embedded in the back of the cathode electrode plate to measure the temperature at different locations in a single cell. These temperature sensors are thin-film temperature sensors from Minggan Technology Co., Ltd., with a thickness ≤500μm and a thermistor diameter ≤3mm. The measurement temperature range covers the fuel cell's operating temperature range, enabling monitoring of localized overheating caused by membrane dryness, flooding, and accelerated membrane electrode corrosion, and identifying the faulty single cell and the location of localized overheating. Real-time temperature and pressure monitoring data are transmitted wirelessly to a monitoring platform for monitoring and analysis of the fuel cell stack's health status.

[0045] like Figure 3As shown in the figure, this embodiment discloses a fuel cell health monitoring method based on joint pressure and temperature monitoring, including: First, during the fuel cell stack operation phase, the system simultaneously collects two types of core parameters: inlet and outlet pressures of the flow channel (to reflect gas flow resistance) and individual cell temperature (to reflect local electrochemical reactions and thermal states), and transmits these data to the monitoring platform for processing and storage. The monitoring platform then performs threshold comparison on the data to determine whether the pressure and temperature are abnormal. If the parameters are within the normal range, the process returns to the fuel cell stack operation phase for continuous cyclic monitoring; if the parameters are abnormal, the platform analyzes the fault type based on specific abnormal characteristics, such as flooding faults, membrane dryness faults, membrane rupture and gas leakage faults, etc. After determining the fault type, the system further locates the specific location of the abnormal individual cell, and then determines whether shutdown maintenance is required based on the severity and type of the fault. If no shutdown is required, the main control module receives abnormal status information and performs operations such as regulating the intake humidity, adjusting the gas flow rate, and regulating the stack temperature. After the regulation is completed, it returns to the fuel cell stack operation phase to continue monitoring. If a shutdown is required (such as a serious fault like membrane rupture or gas leakage), it immediately performs unloading shutdown and cuts off the gas supply as a safety operation. The process ends at the end, and subsequent manual maintenance or replacement of the faulty components is required.

[0046] This embodiment proposes a novel design for embedded sensors in the electrode plates. Pressure sensors 1011, 1012, 1011', and 1012' from Minggan Technology Co., Ltd. are embedded at the inlet and outlet of the flow channels on the cathode and anode plates of a single cell. These sensors are ≤0.3mm thick and transmit data wirelessly. They can monitor pressure changes in the cathode and anode flow channels and detect gas blockage through the pressure difference between the inlet and outlet. Simultaneously, temperature sensors 1031, 1032, and 1033 from Minggan Technology Co., Ltd. are embedded on the back of the cathode electrode plate. These sensors are ≤500μm thick, with a thermistor diameter ≤3mm, and transmit data wirelessly. They can monitor temperature changes at different locations within the single cell, covering the fuel cell's operating temperature range, and locate faulty cells and overheated areas. Real-time temperature and pressure monitoring data are transmitted wirelessly to a monitoring platform, which monitors and analyzes the health status of the fuel cell stack.

[0047] In this embodiment, during fuel cell stack operation, the inlet and outlet pressures of the flow channel and the temperature of each individual cell are first collected and transmitted to the monitoring platform. The platform determines whether these parameters are abnormal: if the parameters are normal, it returns to the stack operation phase for continuous monitoring; if the parameters are abnormal, it analyzes the fault type (flooding, membrane dryness, membrane rupture, gas leakage, etc.) based on the abnormal characteristics of pressure difference and temperature, then locates the abnormal individual cell, and subsequently determines whether a shutdown maintenance is required. If no shutdown is required, the main control module receives the status information and performs control operations such as intake humidity, gas flow rate, and stack temperature, and then returns to the operation cycle to continue monitoring. If a shutdown is required, the system is unloaded, the gas supply is cut off, and the process ends.

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A fuel cell health monitoring method based on pressure and temperature combined monitoring, characterized in that, include: The temperature and flow pressure of individual cells in the fuel cell stack are collected at multiple points. The temperature and flow pressure at multiple points are used to determine whether a fault has occurred, analyze the fault type, and locate the fault location. Determine whether to shut down for maintenance based on the fault type and location. If no shutdown is required, take control measures. 2.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The data collection includes multi-point temperature and flow channel pressure of individual cells in the fuel cell stack, including: Flexible pressure sensors are embedded at the inlet and outlet of the flow channels of the cathode and anode plates in the single cell to monitor pressure changes in the cathode and anode flow channels, and multiple temperature sensors are embedded on the back of the cathode plate to detect the temperature of the single cell at multiple points. 3.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The multi-point temperature and the flow channel pressure are used to determine whether a fault has occurred, and the fault type is analyzed, including: The multi-point temperature and the flow channel pressure are compared to determine whether any point temperature and flow channel pressure are abnormal. If abnormal, the fault type is analyzed. If not abnormal, the multi-point temperature and flow channel pressure of a single cell in the fuel cell stack are collected again for fault judgment. 4.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The fault types analyzed include: When the pressure difference between the inlet and outlet of the cathode and anode channels of a single cell is greater than the upper limit of the target threshold and the temperature at any point continues to drop, it is proven that the fault is a flooding fault. When the pressure difference between the inlet and outlet of the cathode and anode channels of a single cell is less than the lower limit of the target threshold and the temperature at any point continues to rise, it is proven that the fault is a membrane dry fault. When the pressure between the inlet and outlet of the cathode and anode channels of a single cell changes abruptly and the temperature at any point changes drastically, it is proven that the fault is a membrane rupture and gas leakage. 5.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The aforementioned regulatory measures include: If a flooding fault occurs in a localized cell that is not exceeding the target number, the anode three-way valve and cathode three-way valve will be activated to perform a pulse-type purging on the flow channel corresponding to the flooded cell. This involves increasing the opening of the hydrogen or oxygen regulating valve on the side corresponding to the faulty flow channel to increase the air intake flow rate, while simultaneously slightly opening the corresponding anode or cathode back pressure valve to reduce the back pressure in the flow channel. This creates a momentary high-flow-rate purging and drainage process. During the purging process, the humidification power of the corresponding anode or cathode humidifier will be reduced simultaneously to temporarily lower the relative humidity of the intake air until the monitoring parameters corresponding to the localized cell return to the normal range. After this, the purging will stop and the rated air supply will be restored. If more than the target number of individual cells experience flooding, then the entire stack will be coordinated to drain water. Simultaneously, the opening of the hydrogen and oxygen regulating valves will be increased to improve the overall anode and cathode airflow. The anode and cathode back pressure valves will be adjusted to increase the gas flow rate in the flow channels while maintaining stable internal pressure. The humidification capacity of the anode and cathode humidifiers will be reduced to lower the relative humidity of the intake air. At the same time, the coolant circulation pump flow rate will be reduced. In conjunction with the heat exchanger and fan, the stack operating temperature will be slightly increased to accelerate the evaporation of liquid water. Once the monitoring parameters corresponding to the individual cells of the entire stack return to the normal range, the rated operating parameters will be gradually restored. 6.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The aforementioned regulatory measures also include: If a localized cell experiences membrane dryness failure (not exceeding the target number), the anode or cathode humidifier on the corresponding side of the faulty flow channel will be activated to temporarily increase humidification power. Simultaneously, the opening of the corresponding hydrogen or oxygen regulating valve will be slightly reduced to decrease gas flow rate and extend the residence time of humidified gas, thereby enhancing the proton exchange membrane hydration effect. The fan speed will be slightly increased to decrease the coolant return water temperature, bringing the stack operating temperature back to the lower limit of the rated range. This process will continue until the monitoring parameters corresponding to the localized cell return to the normal range, at which point the rated operating parameters will be gradually restored. If a localized cell experiences membrane dryness failure (exceeding the target number), the humidification power of the anode and cathode humidifiers will be increased to relatively increase the humidity of the anode and cathode intake air. The hydrogen and oxygen regulating valves will be adjusted simultaneously to slightly reduce the overall stack intake air flow rate, extending the residence time of humidified gas and enhancing the overall proton exchange membrane hydration effect. At the same time, the fan speed will be increased and the coolant circulation pump flow rate will be adjusted to stabilize the stack operating temperature within the rated operating temperature range. This process will continue until the monitoring parameters corresponding to the entire stack's cells return to the normal range, at which point the rated operating parameters will be gradually restored. 7.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The aforementioned regulatory measures also include: If the inlet and outlet pressures of the cathode and anode channels of a single cell suddenly change abnormally to less than the first target value and the temperature at any point suddenly changes to less than the second target value, and there is no hydrogen leak alarm, then the stack output operating current is reduced to the target rated current, and the anode back pressure valve and cathode back pressure valve are adjusted synchronously to control the anode-cathode pressure difference within the target range to suppress the escalation of the fault. At the same time, the pressure, temperature of the faulty single cell and the hydrogen leak concentration of the entire stack are monitored. If the parameters continue to deteriorate, a shutdown maintenance is immediately triggered. If the inlet and outlet pressures of the cathode and anode channels of a single cell suddenly change abnormally to greater than the first target value and the temperature at any point suddenly changes to greater than the second target value, or a hydrogen leak alarm is triggered, then a shutdown maintenance is immediately performed, that is, the stack load is completely unloaded, the hydrogen regulating valve and oxygen regulating valve are closed synchronously to cut off the supply of hydrogen and oxygen, and then the anode back pressure valve and cathode back pressure valve are fully opened to safely vent the residual gas in the stack. At the same time, the location information of the faulty single cell is uploaded and locked for storage. 8.The fuel cell health monitoring method based on pressure and temperature combined monitoring according to claim 1, wherein, The aforementioned regulatory measures also include: The operating current is obtained, and the gas supply flow rate and pressure are adjusted based on the demand of the operating current, that is, the opening of the inlet valve is increased to increase the gas supply, and the opening of the back pressure valve is decreased to increase the gas pressure.

9. A fuel cell health monitoring device based on combined pressure and temperature monitoring, implemented by the method of any one of claims 1-8, characterized in that, include: The data acquisition module is used to collect multi-point temperature and flow channel pressure of individual cells in the fuel cell stack; The monitoring module is used to determine whether a fault has occurred by using the multi-point temperature and the flow channel pressure, analyze the fault type, and locate the fault location. The main control module is used to determine whether to stop the machine for maintenance based on the fault type and the fault location. If no shutdown for maintenance is required, control measures are taken.

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