A fuel cell stack testing apparatus and method suitable for low temperature environments

Abstract

The application discloses a fuel cell stack test equipment and method suitable for low-temperature environment. The method is characterized by the particularity of the low-temperature environment of-40 DEG C to 0 DEG C, and provides a low-temperature adaptation type test equipment, which comprises a low-temperature preheating module, a low-temperature resistant data acquisition module, a temperature control system and a low-temperature sealing module. Through the whole-process standardization and normalization use method of the coordinated adaptation, the preheating, adaptation, test, abnormality and protection whole-link standardized operation process is adopted, which is different from the existing normal-temperature test use method, and the five core problems of low-temperature preheating, low-temperature calibration, low-temperature adaptation, low-temperature abnormality treatment and low-temperature protection are solved.

Description

Technical Field

[0001] This invention belongs to the field of fuel cells, specifically relating to a method for using a fuel cell stack testing device suitable for low-temperature environments. Background Technology

[0002] As the "heart" of a fuel cell system, the fuel cell stack's low-temperature start-up performance and low-temperature operational reliability directly determine the adaptability and promotion value of fuel cell products in cold regions. Low-temperature start-up performance and low-temperature operational reliability have become core evaluation indicators, leading to an increasingly urgent need for corresponding low-temperature environmental testing. However, existing fuel cell stack testing equipment primarily targets conventional low-temperature testing and has limitations when used in environments ranging from -40℃ to 0℃.

[0003] Currently, existing technologies related to cryogenic cold start have formed two main technical paths: "equipment structure optimization" and "process operation optimization." These cover different scenarios, from simple testing to high-end R&D testing, and can achieve basic cold start performance testing of fuel cell stacks, providing some reference for cryogenic fuel cell stack R&D. However, these solutions all have obvious inherent defects and have not solved the core pain points such as poor testing stability, low accuracy, non-standardized processes, narrow compatibility, and delayed anomaly handling in low-temperature environments.

[0004] For example, the existing published patent CN119029249A, a test device and test method for low-temperature cold start of fuel cell stacks, does not take into account the special characteristics of low-temperature environment, and does not design low-temperature preheating, low-temperature calibration, low-temperature protection and standardized low-temperature anomaly handling process. It cannot meet the test requirements in low-temperature environment of -40℃~0℃, which limits the application and research and development process of fuel cell stacks in low-temperature scenarios. Summary of the Invention

[0005] To address the shortcomings of existing fuel cell stack testing equipment methods, such as inability to adapt to low-temperature environments, low testing accuracy, easy equipment damage, non-standard processes, and delayed anomaly handling, this invention provides a method for using fuel cell stack testing equipment suitable for low-temperature environments, taking into account the actual needs of fuel cell stack testing in low-temperature environments.

[0006] The specific objectives achieved by this invention are as follows:

[0007] 1. Achieve stable start-up and operation of equipment in low-temperature environments: Through standardized low-temperature preheating processes, improve the success rate of equipment start-up in environments ranging from -40℃ to 0℃, reduce the damage rate of equipment components by more than 70%, and extend the service life of equipment.

[0008] 2. Improve the accuracy of low-temperature testing and ensure data reliability: Design a dynamic parameter calibration strategy for low-temperature environments to reduce the test data error from the current ≥15% to ≤7%, providing an accurate basis for the low-temperature performance evaluation of fuel cell stacks.

[0009] 3. Establish a standardized low-temperature testing process: Develop standardized operating procedures for the entire process, including "low-temperature environment pretreatment - equipment preheating - fuel cell stack adaptation - low-temperature testing - anomaly handling - equipment protection", unify the operating steps for low-temperature start-up and low-temperature operation testing, and reduce differences in human operation.

[0010] 4. Standardize low-temperature anomaly handling and improve test safety: Design standardized low-temperature anomaly detection, alarm and handling procedures with an anomaly response time of ≤0.2s. It can quickly handle common low-temperature anomalies such as gas leaks and pipeline blockages, prevent the fault from escalating and improve test safety.

[0011] 5. Improve the protection and maintenance of cryogenic equipment: Design targeted cryogenic protection and maintenance procedures to reduce equipment condensation and component aging, reduce equipment maintenance costs by ≥15%, and further improve equipment lifespan and usability.

[0012] 6. Adaptable to low-temperature testing of multi-power fuel cell stacks: It is compatible with low-temperature testing of fuel cell stacks with different power ratings from 10kW to 200kW, without the need to change the testing equipment or make significant adjustments to the operating procedures. It has strong versatility and is suitable for different scenarios such as R&D and mass production quality inspection.

[0013] This invention addresses the unique characteristics of low-temperature environments ranging from -40℃ to 0℃ by providing a standardized and regulated method for the entire process of coordinating with low-temperature compatible testing equipment (equipped with a low-temperature preheating module, a low-temperature resistant data acquisition module, a temperature control system, and a low-temperature sealing module). It adopts a standardized operating procedure covering preheating, adaptation, testing, anomaly handling, and protection, which differs from existing room-temperature testing methods. It focuses on solving five core issues: low-temperature preheating, low-temperature calibration, low-temperature adaptation, low-temperature anomaly handling, and low-temperature protection.

[0014] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0015] A fuel cell stack testing method suitable for low-temperature environments is disclosed. This method is applicable to standard low-temperature testing requirements from -30℃ to 0℃, and can be extended to low-temperature conditions from -40℃ to -30℃, covering an overall application range of -40℃ to 0℃. It is compatible with fuel cell stack testing equipment equipped with a low-temperature preheating module, a low-temperature resistant data acquisition module, a temperature control system, and a fault early warning module. It can perform low-temperature start-up testing, low-temperature performance testing, and low-temperature reliability testing of 10kW-200kW fuel cell stacks. The specific steps are as follows:

[0016] (1) Place the test equipment in the test site and stabilize the ambient temperature of the site at the preset test temperature of -40℃~0℃, with temperature fluctuation ≤±1℃. Maintain this temperature for 20-40 minutes. After the site temperature stabilizes, start the low temperature program of the test equipment for preheating to ensure that the test equipment is compatible with the low temperature environment of the site.

[0017] (2) Place the fuel cell stack under test in the test site and perform low temperature adaptation treatment. Then install the fuel cell stack into the test equipment. Connect the voltage output terminal, current output terminal, reaction gas inlet and outlet, and cooling system interface of the fuel cell stack to the low temperature resistant data acquisition module, gas regulation module, and temperature control system of the test equipment, respectively. Perform a comprehensive airtightness check to confirm that there is no gas or coolant leakage.

[0018] (3) Based on the test types of low-temperature start-up test, low-temperature performance test, and low-temperature reliability test, set standardized test parameters. The specific standards are as follows:

[0019] 1. Low temperature start-up test: sampling frequency 5 times / s, test duration 30min, start-up voltage threshold, start-up current threshold, record stack start-up time and parameter changes during start-up;

[0020] 2. Low temperature performance test: The sampling frequency is 3 times / s, the test duration is 60 minutes, the load gradient is tested, and each load gradient is run for 10-15 minutes. The voltage, current and temperature parameters of the fuel cell stack under different loads are recorded.

[0021] 3. Low-temperature reliability test: The sampling frequency is 4 times / second, the test duration is 72 hours, and the operating condition is set to start-stop cycle. The changes in fuel cell performance and equipment operating status during the cycle are recorded. At the same time, the low-temperature alarm thresholds for various parameters are set. The voltage and current alarm thresholds are adjusted by ±5% compared with the normal temperature threshold, and the temperature alarm threshold is set according to the test environment temperature to avoid false alarms at low temperatures. Then the test is started and the system enters the low-temperature test state.

[0022] (4) Compare and analyze the real-time collected test data to ensure that the measured data is within the allowable reasonable range and that the test process strictly follows the standardization requirements. If an abnormal situation occurs during the test, start the emergency stop procedure, cut off the power supply of the equipment, the connection of the fuel cell stack and the supply of the reaction gas, shut down the temperature control system, protect the safety of the fuel cell stack and the test equipment, and then investigate. The cause of the abnormality found shall be handled in accordance with the corresponding standardized handling specifications. After handling, restart the equipment preheating procedure. After confirming that the equipment and fuel cell stack are in normal condition, the equipment will automatically return to the test state before the abnormality occurred and continue to complete the test.

[0023] (5) After the test reaches the preset time or the test is manually terminated, disconnect the operating condition simulation module and the supply of reaction gas of the equipment, shut down each acquisition module, and start the stack cooling program; after the cooling is completed, disconnect all connections between the stack and the test equipment, remove the stack to be tested, and transfer the stack to a dry environment at room temperature for storage; and perform low temperature protection on the equipment.

[0024] In the above test method, in step (1), the preheating is to set an appropriate preheating temperature and preheating time according to the current ambient temperature. Specifically, when the ambient temperature is -40℃ to -20℃, the preheating temperature is set to 8 to 12℃ and the preheating time is 25 to 35 minutes; when the ambient temperature is -20℃ to 0℃, the preheating temperature is set to 3 to 7℃ and the preheating time is 15 to 25 minutes.

[0025] In the above test method, in step (1), the preheating is a segmented gradient preheating, specifically: first preheat the electronic component module, then preheat the pipe and sealing module, and finally preheat the whole at a constant temperature for 5-10 minutes, which adapts to the low temperature tolerance characteristics of different modules and can also avoid insufficient or overheating of local preheating, ensuring the stability of equipment startup; the preheating temperature of the electronic component module is 10~14℃ and the duration is 10-15 minutes; the preheating temperature of the pipe and sealing module is 6~10℃ and the duration is 15-20 minutes.

[0026] In the above test method, in step (3), the voltage threshold is set according to the rated voltage of the fuel cell stack, with an error of ±0.5V; the current threshold is set according to the rated current of the fuel cell stack, with an error of ±1A.

[0027] The load gradients are 0%, 25%, 50%, 75%, and 100% of the rated load.

[0028] The start-stop cycle consists of 5 minutes of startup, 30 minutes of operation, and 5 minutes of shutdown, repeating continuously.

[0029] In the above test method, the abnormal conditions in step (4) include fuel cell overvoltage, fuel cell overcurrent, fuel cell overtemperature, fuel cell undervoltage, reaction gas leakage, pipeline blockage, or equipment module failure.

[0030] In the above test method, in step (4), the processing according to the corresponding standardized processing specifications is as follows: if the interface is loose, reconnect and lock it; if the seal fails, replace the low temperature seal and retest; if the pipe is blocked, clean the pipe and check it; if the parameter setting is incorrect, adjust the parameter and re-verify it; if the fuel cell stack is abnormal, stop the test and replace the fuel cell stack.

[0031] In the above test method, in step (4), the preheating time in the preheating program is 8-12 minutes.

[0032] In the above test method, in step (5), the cooling procedure is as follows: under the condition of cooling rate ≤ 5℃ / min, the temperature of the fuel cell stack is slowly reduced to the test environment temperature.

[0033] This method focuses on low-temperature adaptation, accurate testing, safety and reliability, and standardized efficiency. It forms a standardized process of low-temperature environment pretreatment and equipment preheating, low-temperature adaptation and installation of fuel cell stacks, setting test parameters and low-temperature start-up testing, automated low-temperature test operation and anomaly handling, and test completion and equipment low-temperature protection. It does not require professional low-temperature testing personnel to be on duty throughout the process and can stably complete the low-temperature start-up, performance and reliability testing of 10kW-200kW fuel cell stacks, thus solving the shortcomings of existing technologies.

[0034] The fuel cell stack testing equipment compatible with the above testing methods must have the following basic structure: a low-temperature preheating module, a low-temperature resistant data acquisition module, a temperature control system, a gas regulation module, a low-temperature sealing interface, and a fault early warning module. Figure 1 The diagram shows the connections between the modules. The modules work together to provide equipment support for standardized usage methods in low-temperature environments. The specific connection structure is as follows: the low-temperature resistant data acquisition module is connected to the temperature control system, the low-temperature preheating module, the gas regulation module, and the fault early warning module, respectively. The temperature control system, the gas regulation module, the fault early warning module, and the low-temperature preheating module are connected to the low-temperature sealing interface, and the low-temperature sealing interface is connected to the fuel cell stack.

[0035] The function of the low-temperature preheating module in this invention is to adapt to the low-temperature testing environment of -40℃ to 0℃, and to perform segmented gradient preheating or adaptive preheating on the core components of the testing equipment (electronic component module, pipe and sealing component module, etc.) to avoid damage such as embrittlement and cracking of equipment components due to instantaneous low temperature.

[0036] The function of the low-temperature resistant data acquisition module in this invention is to acquire multiple core parameters in real time throughout the entire process of low-temperature testing of the fuel cell stack, including the total voltage of the fuel cell stack, the voltage of each cell, the current, the temperature of the fuel cell stack core, and the temperature of the coolant. It has excellent low-temperature tolerance and anti-interference capabilities, and can effectively counteract the interference of the low-temperature environment on the acquisition module body, signal transmission lines and connection interfaces.

[0037] The function of the temperature control system in this invention is to: adjust the internal and external circulation mode of the cooling circuit in real time, control the heating and cooling rate of the fuel cell stack, avoid excessive temperature difference that could damage fuel cell stack components or cause test data deviation; and provide a stable temperature environment for fuel cell stack low-temperature adaptation, cold start testing, and low-temperature performance testing.

[0038] The function of the gas regulation module in this invention is to precisely regulate the intake flow rate, pressure and humidity of hydrogen and air used in the fuel cell stack to ensure a stable gas environment during cold start; and to cut off the gas source and introduce inert gas to purge residual hydrogen in the pipeline when receiving an emergency stop signal.

[0039] The function of the low-temperature sealing interface in this invention is to: select a low-temperature embrittlement-resistant material, adapt to the low-temperature environment of -40℃ to 0℃, prevent the interface from breaking due to low-temperature embrittlement; enhance the sealing performance of the interface, eliminate the leakage of reactive gas and coolant during the test, and ensure the safety of the test environment.

[0040] The fault warning module in this invention functions as follows: it receives test data transmitted from the low-temperature resistant data acquisition module in real time, compares it with preset standardized test parameters and low-temperature alarm thresholds, and monitors whether the parameter deviation exceeds the allowable range; when faults such as gas leakage, ice crystal blockage, voltage drop, and abnormal temperature occur, it promptly issues audible and visual warning signals and simultaneously triggers the emergency stop procedure.

[0041] Compared with the prior art, the advantages of the present invention are:

[0042] 1. Low-temperature start-up guarantee: Enables stable start-up of equipment in the full low-temperature range of -40℃ to 0℃, reduces the risk of damage to equipment components due to low-temperature embrittlement and jamming, ensures stable operation of equipment, and improves the success rate of equipment start-up.

[0043] 2. Optimized test accuracy: This invention optimizes the parameter calibration method to counteract low-temperature interference, reduce test data errors, and improve data repeatability and accuracy, providing precise support for the low-temperature performance evaluation of fuel cell stacks.

[0044] 3. Process standardization: Establish standardized operating procedures for all stages of testing, unify operating steps and parameter settings, reduce differences in human operation, and ensure that tests are reproducible and results are comparable.

[0045] 4. Low-temperature protection and maintenance: Improve the low-temperature protection and maintenance procedures for equipment and fuel cells after testing to avoid condensation and component aging, extend equipment life and reduce maintenance costs.

[0046] 5. Rapid handling of anomalies: Establish standardized procedures for detecting, alarming, and handling low-temperature anomalies to quickly respond to common anomalies such as gas leaks and pipeline blockages, prevent the escalation of faults, and ensure test safety.

[0047] 6. Universal compatibility: This invention is compatible with fuel cell stacks of different power ratings from 10kW to 200kW, and adapts to various test types such as low-temperature start-up, performance, and reliability, meeting the diverse needs of R&D, mass production quality inspection, and other scenarios. Attached Figure Description

[0048] Figure 1 This is a diagram showing the module connections in the testing equipment of this invention.

[0049] Figure 2 This is a flowchart of the testing method.

[0050] Figure 3This is a schematic diagram of the connection of the low-temperature testing equipment.

[0051] The components shown in the diagram are as follows: 1. Test equipment control cabinet; 2. Low-temperature simulation chamber of the test equipment; 3. Fuel cell stack; 4. Low-temperature resistant data acquisition module; 5. Fault early warning module; 6. Temperature control system; 7. Low-temperature preheating module; 8. Low-temperature sealing interface; 9. Gas conditioning module. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0053] Example 1

[0054] This embodiment provides a testing device, which is as follows: Figure 3 As shown, the test equipment consists of a control cabinet 1 and a cryogenic simulation chamber 2. The fuel cell stack 3 to be tested is placed inside the cryogenic simulation chamber 2. Figure 1 As shown, the test equipment includes a low-temperature preheating module 7, a low-temperature resistant data acquisition module 4, a temperature control system 6, a gas regulation module 9, a low-temperature sealing interface 8, and a fault early warning module 5. The low-temperature resistant data acquisition module 4 is connected to the temperature control system 6, the low-temperature preheating module 7, the gas regulation module 9, and the fault early warning module 5, respectively. The temperature control system 6, the gas regulation module 9, the fault early warning module 5, and the low-temperature preheating module 7 are connected to the low-temperature sealing interface 8, and the low-temperature sealing interface 8 is connected to the fuel cell stack 3.

[0055] The functions of each module are described below:

[0056] The low-temperature preheating module is adapted to a low-temperature testing environment of -40℃ to 0℃. It is used to perform segmented gradient preheating or adaptive preheating of the core components of the testing equipment to prevent damage such as embrittlement and cracking of the equipment components due to instantaneous low temperature. The core components of the testing equipment include an electronic component module and a pipeline and sealing component module.

[0057] The low-temperature resistant data acquisition module is used to collect multiple core parameters in real time throughout the entire process of low-temperature testing of the fuel cell stack, including total stack voltage, single-cell voltage, current, stack core temperature, and coolant temperature.

[0058] The temperature control system is used to adjust the internal and external circulation mode of the cooling loop in real time, control the heating and cooling rate of the fuel cell stack, avoid excessive temperature difference that may cause damage to fuel cell stack components or deviation of test data, and provide a stable temperature environment for fuel cell stack low temperature adaptation, cold start test and low temperature performance test.

[0059] The gas regulation module is used to control and regulate the supply of hydrogen, air, and inert gas, and to control the flow rate, humidity, and pressure in real time. It prevents the fuel cell stack from being damaged due to insufficient gas flow or excessive pressure difference. After receiving the trigger alarm and emergency stop command, it quickly cuts off the hydrogen and air inlet valves and automatically introduces nitrogen to purge and replace the residual gas in the pipeline.

[0060] The fault early warning module is used to receive test data transmitted by the low-temperature resistant data acquisition module in real time, compare it with the preset standardized test parameters and low-temperature alarm threshold, and monitor whether the parameter deviation exceeds the allowable range. When faults such as gas leakage, ice crystal blockage, voltage drop, and abnormal temperature occur, it promptly issues audible and visual warning signals and simultaneously triggers the emergency stop procedure.

[0061] Example 2

[0062] A fuel cell stack testing method suitable for low-temperature environments, such as Figure 2 As shown, it includes the following steps:

[0063] Step 1: Low-temperature environment pretreatment and equipment preheating. This step is to solve the problems of difficult equipment startup and easy damage to components;

[0064] 1.1 Environmental pretreatment: Move the test equipment to the designated test site, ensuring that the site is sealed, dust-free, free of flammable and explosive materials, and well-ventilated; start the site temperature system and stabilize the ambient temperature at the preset test temperature (-40℃~0℃), with temperature fluctuations ≤±1℃, and maintain for 20-40 minutes to ensure uniform and stable ambient temperature.

[0065] 1.2 Equipment Inspection and Fixing: Inspect the appearance of the test equipment, the pipes, and the sealing of the interfaces to ensure there is no damage or looseness; lock the lockable casters at the bottom of the equipment to ensure stability; connect the main power supply, reaction gas pipes (hydrogen, oxygen), and cooling pipes, and check the pipe sealing to prevent gas leakage at low temperatures.

[0066] 1.3 Standardized Low-Temperature Preheating: Turn on the main power of the equipment and start the low-temperature preheating program through the equipment touch control panel or cloud platform. Set the appropriate preheating temperature and preheating time according to the current ambient temperature. The specific adaptation standards are as follows: when the ambient temperature is -40℃ to -20℃, the preheating temperature is set to 10℃ and the preheating time is 30 minutes; when the ambient temperature is -20℃ to 0℃, the preheating temperature is set to 5℃ and the preheating time is 20 minutes. During the preheating process, the temperature control system automatically adjusts to ensure that all modules of the equipment (acquisition module, electronic components, pipelines) are preheated evenly, and the module temperature is monitored in real time to avoid local overheating or insufficient preheating.

[0067] 1.4 Self-test and calibration after preheating: After preheating, start the equipment self-test program to check the status of each system and module to ensure that there are no fault alarm prompts; start the parameter dynamic calibration program to perform comprehensive calibration on the voltage, current, pressure, temperature and humidity acquisition modules. The calibration frequency is set to once every 20 seconds to ensure that the test data error is ≤3%. The calibration record is automatically uploaded to the cloud and stored locally for easy traceability.

[0068] Step 2: Low-temperature adaptation and installation of fuel cell stack. This step is to solve the problems of fuel cell stack installation, adaptation and sealing at low temperatures.

[0069] 2.1 Low-temperature adaptation of fuel cell stack: Place the fuel cell stack to be tested in the test site and perform a 15-minute low-temperature adaptation treatment to ensure that the temperature of the fuel cell stack is basically the same as the ambient temperature of the test site. Then, install the fuel cell stack in the test equipment to avoid damage to fuel cell stack components or deviation of test data due to excessive temperature difference.

[0070] 2.2 Adjustment and Fixing of Mounting Platform: Based on the power and size of the fuel cell stack to be tested, and in accordance with standardized adjustment specifications, the height of the fuel cell stack mounting platform can be adjusted to correspond with the platform size by adjusting the bolts, so that the mounting platform and the fuel cell stack size are precisely matched; after adjustment, the adjusting bolts are locked, and the fuel cell stack is firmly fixed with special low-temperature adapter fasteners to prevent the fuel cell stack from shaking during the test. The fasteners are made of low-temperature embrittlement resistant material to avoid breakage at low temperatures.

[0071] 2.3 Interface docking and sealing: Through the equipment's low-temperature sealing interface and matching low-temperature adapter, the high and low voltage wiring harnesses, reaction gas inlet and outlet, and cooling pipe interfaces of the fuel cell stack are precisely docked with the low-temperature resistant data acquisition module, gas regulation module, and temperature control system of the testing equipment, respectively. During docking, the interface is sealed with a low-temperature sealing component to ensure a tight connection and good contact, and to prevent gas leakage and condensate seepage at low temperatures.

[0072] 2.4 Post-connection inspection: According to the standardized checklist, check the stack fixation status, interface connection status, wiring correctness and sealing performance one by one; start the sealing test procedure to test the sealing of the reaction gas pipeline and interface. The test pressure is 0.1MPa. No leakage is considered qualified; if the seal is unqualified, immediately reconnect and seal until the test is qualified; after the inspection is completed, record the inspection results and associate them with subsequent test data.

[0073] Step 3: Test parameter settings and low-temperature start-up test;

[0074] 3.1 Fuel Cell Stack Information Input: Access the test parameter setting interface via the device touch panel or cloud platform, and input the basic information of the fuel cell stack to be tested (model, power, rated voltage, rated current, low temperature start-up requirements) according to the standardized input specifications. The information is automatically saved after input and is associated with subsequent test data and calibration records for easy data traceability.

[0075] 3.2 Test Parameter Settings: Based on the test type (low temperature start-up test / low temperature performance test / low temperature reliability test), set standardized test parameters as follows:

[0076] (1) Low temperature start-up test: sampling frequency 5 times / s, test duration 30min, start-up voltage threshold (set according to the rated voltage of the fuel cell stack, error ±0.5V), start-up current threshold (set according to the rated current of the fuel cell stack, error ±1A), record the fuel cell stack start-up time and parameter changes during the start-up process.

[0077] (2) Low temperature performance test: The sampling frequency is 3 times / s, the test duration is 60min, the test load gradient (0%, 25%, 50%, 75%, 100% rated load), each load gradient is run for 12min, and the voltage, current, temperature and other parameters of the fuel cell stack under different loads are recorded.

[0078] (3) Low-temperature reliability test: The sampling frequency is 4 times / s, the test duration is 72h, and the operating condition is set to start-stop cycle (start for 5min, run for 30min, stop for 5min, repeating repeatedly). The changes in fuel cell performance and equipment operating status during the cycle are recorded. At the same time, the low-temperature alarm thresholds of various parameters are set. The voltage and current alarm thresholds are adjusted by ±5% compared with the normal temperature threshold. The temperature alarm threshold is set according to the test environment temperature to avoid false alarms at low temperatures.

[0079] 3.3 Operating Condition Simulation and Startup Settings: Start the operating condition simulation program and retrieve the preset low-temperature operating condition parameters according to the test type, without the need for reprogramming; support manual editing of operating condition parameters, which can be saved to the device or cloud for later reuse; set the test startup mode (automatic startup / manual startup), with automatic startup mode as the default and a startup delay time of 10 seconds set to avoid operator error.

[0080] 3.4 Test Start: After confirming that the test parameters, operating procedures and interface connections are correct, click the "Start Test" button. The equipment will automatically enter the low temperature test state and generate a unique test number (including fuel cell model, test date and test type) for subsequent data traceability and query.

[0081] Step 4: Automated low-temperature test operation and anomaly handling. This step addresses the issues of delayed response and escalation of faults in low-temperature anomalies.

[0082] 4.1 Fully Automated Operation: During testing, all modules of the equipment work together to simulate operating conditions. Modules accurately simulate low-temperature test conditions according to preset programs. The low-temperature resistant data acquisition module synchronously collects various test data of the fuel cell stack, and the dynamic calibration module automatically calibrates the data every 30 seconds. During the test, the voltage measurement error is 3.9%, the current measurement error is 3.7%, and the temperature measurement error is 3.2%. The data repeatability of 5 tests on the same fuel cell stack is 99.1%. Under the same test conditions, without the automatic calibration function enabled, the voltage measurement error is 12.1%, the current measurement error is 11.5%, and the temperature measurement error is 10.7%. The data repeatability of 5 tests on the same fuel cell stack is 83.5%. Enabling automatic calibration can offset low-temperature interference and ensure test accuracy. The temperature control system adjusts the test environment temperature and fuel cell stack temperature in real time to maintain temperature stability. Test data is transmitted to the intelligent control module in real time and simultaneously uploaded to the cloud data traceability module to realize real-time data display, storage, and analysis.

[0083] 4.2 Real-time monitoring: Operators can view test data, operating status, equipment status and ambient temperature in real time through the equipment touch panel or cloud platform without on-site supervision; the equipment automatically records all operations, parameter changes and equipment operation logs during the test process, forming a complete test record, which is automatically uploaded to the cloud for easy follow-up.

[0084] 4.3 Standardized Anomaly Handling: During testing, if the fault warning module detects an anomaly (overvoltage, overcurrent, overtemperature, undervoltage, reaction gas leakage, pipeline blockage, equipment module failure, etc.), it immediately triggers an audible and visual alarm (alarm volume ≥80dB, alarm light flashing red). Simultaneously, the alarm information, anomaly type, and troubleshooting guidance are displayed on the touch panel and cloud platform. Within 0.2 seconds, the emergency shutdown procedure is automatically initiated, cutting off the equipment power supply, fuel cell connection, and reaction gas supply, shutting down the temperature control system, and protecting the fuel cell and test equipment. At the same time, the time of anomaly occurrence, anomaly parameters, anomaly type, and equipment operating status are automatically recorded and uploaded to the cloud along with the test number.

[0085] 4.4 Troubleshooting and Restart: After receiving the alarm information, the operator shall follow the troubleshooting guidelines displayed on the cloud and the equipment, and in light of the characteristics of the low-temperature environment, troubleshoot the cause of the anomaly one by one (such as loose interface, seal failure, pipe blockage, incorrect parameter settings, fuel cell stack malfunction, etc.), and keep a record of the troubleshooting process. Based on the identified cause of the anomaly, handle it according to the corresponding standardized procedures: for loose interfaces, reconnect and lock; for seal failure, replace the low-temperature seal and retest; for pipe blockage, clean and inspect the pipe; for incorrect parameter settings, adjust the parameters and recalibrate; for fuel cell stack malfunction, stop the test and replace the fuel cell stack. After the anomaly is handled, restart the equipment preheating program (preheating time 10 minutes). After confirming that the equipment and fuel cell stack are in normal condition, click the "Restart Test" button. The equipment will automatically return to the test state before the anomaly occurred and continue to complete the test. If the anomaly cannot be handled in a short time or the test does not need to continue, click the "Terminate Test" button. The equipment will automatically complete the final data storage and synchronization, cut off the power to all modules, and enter the test end process.

[0086] Step 5: Test completion and low-temperature protection of equipment. This step addresses issues such as condensation and component aging.

[0087] 5.1 Test Termination and Stack Handling: After the test reaches the preset duration or is manually terminated, the equipment automatically cuts off the operating condition simulation module and the supply of reactive gas, shuts down all acquisition modules, and starts the stack cooling program to slowly reduce the stack temperature to the test environment temperature. The cooling rate is controlled at ≤5℃ / min to avoid excessive temperature difference that could damage the stack components or cause condensation. After cooling is complete, disconnect all connections between the stack and the test equipment (interfaces, wiring, cooling pipes), remove the stack under test, transfer the stack to a dry environment at room temperature for storage, and make proper stack test records.

[0088] 5.2 Data Processing and Report Generation: The equipment automatically completes the final storage and cloud synchronization of test data, ensuring that test data is not lost. The cloud data analysis module automatically analyzes the test data, identifies data anomalies, and generates standardized test reports by combining test parameters and operating condition simulation parameters. The reports highlight low-temperature start-up performance parameters, fuel cell stack performance data under low-temperature conditions, anomaly records (if any), calibration records, etc. After analysis, the report is automatically marked as qualified. Operators can view and download test reports (supporting PDF / Excel formats) through the equipment touch panel or cloud platform. They can also share the reports to designated terminals (such as quality inspection departments and R&D departments) according to standardized procedures for fuel cell stack performance evaluation, fault diagnosis, or quality inspection records. Test data and reports can be stored in the cloud for a long time and can be traced and retrieved at any time by test number, fuel cell stack model, and other information.

[0089] 5.3 Equipment Cleaning and Inspection: Close the reaction gas valve, clean the residual gas in the reaction gas pipeline, and use a low-temperature compatible cleaner to clean the inner wall of the pipeline to prevent residual gas from condensing and clumping; conduct a comprehensive inspection of the test equipment, clean the sensors of the low-temperature data acquisition module and the core components of the operating condition simulation module, remove surface condensate and debris, and ensure that the equipment is free of debris and damage; check the operating status of each module of the equipment and the sealing condition of the pipeline, and record any abnormalities in the equipment operation (if any) for subsequent maintenance.

[0090] 5.4 Low-Temperature Protection and Storage of Equipment: Activate the equipment's low-temperature protection procedure, and perform dustproof and anti-condensation treatment on the equipment interfaces, acquisition modules, and pipelines. Cover the interfaces with protective caps, and introduce dry nitrogen (pressure 0.05MPa) into the pipelines to prevent condensate from entering the equipment. Turn off the main power supply to the equipment and organize the testing tools and auxiliary materials. Move the testing equipment to the designated storage location (low-temperature dry, dust-free, and free of corrosive gases) according to standardized storage specifications, and secure it after unlocking the casters. Keep accurate equipment maintenance records, including test duration, equipment operating status, cleaning status, and abnormality records, to facilitate subsequent equipment maintenance and traceability.

[0091] It should be noted that the method in this embodiment can realize simultaneous low-temperature testing of multiple fuel cell stacks. Operators can control multiple testing devices simultaneously through a cloud platform, set unified test parameters and operating procedures, start tests synchronously, monitor test status in real time, and receive test reports synchronously, which greatly improves the efficiency of low-temperature testing in mass production quality inspection scenarios. At the same time, it supports remote control, allowing operators to complete all operations remotely, further improving operational convenience and reducing the labor cost of low-temperature testing.

[0092] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for testing fuel cell stacks suitable for low-temperature environments, characterized in that, The method is applicable to temperatures ranging from -40℃ to 0℃ and includes the following steps: (1) Place the test equipment in the test site and stabilize the ambient temperature of the site at the preset test temperature of -40℃~0℃, with temperature fluctuation ≤±1℃. Maintain this temperature for 20-40 minutes. After the site temperature stabilizes, start the low temperature program of the test equipment for preheating to ensure that the test equipment is compatible with the low temperature environment of the site. (2) Place the fuel cell stack under test in the test site and perform low temperature adaptation treatment. Then install the fuel cell stack into the test equipment. Connect the high and low voltage wiring harness, reaction gas inlet and outlet, and cooling pipe interface of the fuel cell stack to the low temperature resistant data acquisition module, gas regulation module, and temperature control system of the test equipment respectively. Perform a comprehensive airtightness check to confirm that there is no gas or coolant leakage. (3) Based on the test types of low-temperature start-up test, low-temperature performance test, and low-temperature reliability test, set standardized test parameters. The specific standards are as follows:

1. Low temperature start-up test: sampling frequency 5 times / s, test duration 30min, start-up voltage threshold, start-up current threshold, record stack start-up time and parameter changes during start-up; 2. Low temperature performance test: The sampling frequency is 3 times / s, the test duration is 60 minutes, the load gradient is tested, and each load gradient is run for 10-15 minutes. The voltage, current and temperature parameters of the fuel cell stack under different loads are recorded.

3. Low-temperature reliability test: The sampling frequency is 4 times / second, the test duration is 72 hours, and the operating condition is set to start-stop cycle. The changes in fuel cell performance and equipment operating status during the cycle are recorded. At the same time, the low-temperature alarm thresholds for various parameters are set. The voltage and current alarm thresholds are adjusted by ±5% compared with the normal temperature threshold, and the temperature alarm threshold is set according to the test environment temperature to avoid false alarms at low temperatures. Then the test is started and the system enters the low-temperature test state. (4) Compare and analyze the real-time collected test data to ensure that the measured data is within the allowable reasonable range and that the test process strictly follows the standardization requirements. If an abnormal situation occurs during the test, start the emergency stop procedure, cut off the power supply of the equipment, the connection of the fuel cell stack and the supply of the reaction gas, shut down the temperature control system, protect the safety of the fuel cell stack and the test equipment, and then investigate. The cause of the abnormality found should be handled in accordance with the corresponding standardization handling specifications. After handling, restart the equipment preheating procedure. After confirming that the equipment and fuel cell stack are in normal condition, the equipment will automatically return to the test state before the abnormality occurred and continue to complete the test. (5) After the test reaches the preset time or the test is manually terminated, disconnect the operating condition simulation module and the supply of reaction gas of the equipment, shut down each acquisition module, and start the stack cooling program; after the cooling is completed, disconnect all connections between the stack and the test equipment, remove the stack to be tested, and transfer the stack to a dry environment at room temperature for storage; and perform low temperature protection on the equipment.

2. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (1), the preheating is to set an appropriate preheating temperature and preheating time according to the current ambient temperature. Specifically, when the ambient temperature is -40℃ to -20℃, the preheating temperature is set to 8 to 12℃ and the preheating time is 25 to 35 minutes; when the ambient temperature is -20℃ to 0℃, the preheating temperature is set to 3 to 7℃ and the preheating time is 15 to 25 minutes.

3. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (1), the preheating is a segmented gradient preheating, specifically: first preheating the electronic component module, then preheating the pipe and sealing module, and finally preheating the whole at a constant temperature for 5-10 minutes. This adapts to the low-temperature tolerance characteristics of different modules and can also avoid insufficient or overheating of local preheating, ensuring the stability of equipment startup. The preheating temperature of the electronic component module is 10-14℃ and the duration is 10-15 minutes. The preheating temperature of the pipe and sealing module is 6-10℃ and the duration is 15-20 minutes.

4. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (3), the voltage threshold is set according to the rated voltage of the fuel cell stack, with an error of ±0.5V; the current threshold is set according to the rated current of the fuel cell stack, with an error of ±1A. The load gradients are 0%, 25%, 50%, 75%, and 100% of the rated load. The start-stop cycle consists of 5 minutes of startup, 30 minutes of operation, and 5 minutes of shutdown, repeating continuously.

5. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (4), the abnormal conditions include fuel cell overvoltage, fuel cell overcurrent, fuel cell overtemperature, fuel cell undervoltage, reaction gas leakage, pipeline blockage, or equipment module failure.

6. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (4), the processing according to the corresponding standardized processing specifications is as follows: if the interface is loose, reconnect and lock it; if the seal fails, replace the low temperature seal and retest; if the pipe is blocked, clean the pipe and check it; if the parameter setting is incorrect, adjust the parameter and re-verify it; if the fuel cell stack is abnormal, stop the test and replace the fuel cell stack.

7. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (4), the preheating time in the preheating program is 8-12 minutes.

8. The fuel cell stack testing method suitable for low-temperature environments according to claim 1, characterized in that, In step (5), the cooling procedure is as follows: under the condition of cooling rate ≤ 5℃ / min, the temperature of the fuel cell stack is slowly reduced to the test environment temperature.

9. The testing equipment used in the low-temperature environment fuel cell stack testing method according to claims 1-8 is characterized in that, It includes a low-temperature preheating module, a low-temperature resistant data acquisition module, a temperature control system, a gas regulation module, a low-temperature sealing interface, and a fault early warning module; the low-temperature resistant data acquisition module is connected to the temperature control system, the low-temperature preheating module, the gas regulation module, and the fault early warning module respectively; the temperature control system, the gas regulation module, the fault early warning module, and the low-temperature preheating module are connected to the low-temperature sealing interface; and the low-temperature sealing interface is connected to the fuel cell stack.

10. The testing equipment according to claim 9, characterized in that, The low-temperature preheating module is adapted to a low-temperature testing environment of -40℃ to 0℃. It is used to perform segmented gradient preheating or adaptive preheating of the core components of the testing equipment to prevent damage such as embrittlement and cracking of the equipment components due to instantaneous low temperature. The core components of the testing equipment include an electronic component module and a pipeline and sealing component module. The low-temperature resistant data acquisition module is used to collect multiple core parameters in real time throughout the entire process of low-temperature testing of the fuel cell stack, including total stack voltage, single-cell voltage, current, stack core temperature, and coolant temperature. The temperature control system is used to adjust the internal and external circulation mode of the cooling loop in real time, control the heating and cooling rate of the fuel cell stack, avoid excessive temperature difference that may cause damage to fuel cell stack components or deviation of test data, and provide a stable temperature environment for fuel cell stack low temperature adaptation, cold start test and low temperature performance test. The gas regulation module is used to control the supply and regulation of hydrogen, air and inert gas, and to control the flow rate, humidity and pressure in real time to avoid fuel cell stack failure caused by insufficient gas flow or excessive pressure difference. After receiving the trigger alarm and emergency stop command, it quickly cuts off the hydrogen and air inlet valves and automatically introduces nitrogen to purge and replace the residual gas in the pipeline. The fault early warning module is used to receive test data transmitted by the low-temperature resistant data acquisition module in real time, compare it with the preset standardized test parameters and low-temperature alarm threshold, and monitor whether the parameter deviation exceeds the allowable range. When faults such as gas leakage, ice crystal blockage, voltage drop, and abnormal temperature occur, it promptly issues audible and visual warning signals and simultaneously triggers the emergency stop procedure.

Images