Fault Detection Methods for HVAC Electronic Expansion Valves

Electronic expansion valve leakage detection method for multi-split air conditioners that eliminates the need for expensive and complex hardware-based leak detection. The method employs a simple temperature differential analysis to detect refrigerant leaks in electronic expansion valves on the stop side of the multi-split system. When a leak is detected, the system automatically initiates fan operation to dissipate the refrigerant and sends a signal to the electronic expansion valve to reset it. This approach enables continuous operation of the multi-split system while addressing condensation issues on the stop side without requiring additional hardware.

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Fault detection for air conditioners to quickly find issues with reversed valve insertion. The method involves monitoring temperature differences between liquid pipes and condensation during refrigeration, and between pipes and superheat during heating. If the differences are abnormal, it indicates reversed valve insertion.

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Detecting electronic expansion valve faults in air conditioning systems through real-time monitoring of return air superheat and subcooling conditions. The method measures actual return air temperature and superheat in the system, and compares them against predetermined thresholds for both conditions. When the actual superheat exceeds the threshold, it indicates an abnormal electronic expansion valve. Similarly, when the actual subcooling falls below the threshold, it indicates a faulty electronic expansion valve. This approach enables early detection of valve faults through continuous monitoring of system conditions.

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Detecting electronic expansion valves in air conditioners through a novel approach that combines compressor operating frequency with actual exhaust temperature changes. The method determines valve opening and temperature correction based on these parameters, providing a more accurate diagnosis of valve faults compared to traditional approaches.

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Operating electronic expansion valves in air conditioning units to enhance system reliability and performance. The system monitors refrigerant superheat across the evaporator and identifies superheat faults based on compressor speed or valve position. When a fault is detected, the system automatically stops the compressor and initiates a calibration process for the electronic expansion valve. This proactive approach prevents compressor damage and ensures optimal system operation.

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Diagnosing faults in HVAC flow regulators and actuators to improve reliability and safety. The method involves using sensors to monitor the flow regulator and actuator during operation. By analyzing sensor data, faults like damaged gears, motor bearings, loose connections, or failed electronic components can be detected. It allows distinguishing faults in the flow regulator versus actuator, making targeted repairs easier. This helps address issues like hard-to-access regulators or complex interacting components.

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An intelligent full-frequency inverter roof machine with self-diagnosis of electronic expansion valve coil insertion error. The machine features a unique diagnostic system that monitors the operating parameters of both the first and second circulation systems, which are connected to the indoor heat exchanger. The system calculates the temperature differences between the exhaust and condensate streams in each system, enabling precise detection of coil insertion errors. This enables the machine to automatically correct the coil position, ensuring optimal system performance and preventing compressor damage.

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Automatically detecting electronic expansion valve faults in air conditioning systems through real-time monitoring of valve operation parameters. The method measures the cumulative time of valve opening and closing events against predetermined threshold values, and stops monitoring when either parameter fails to meet these criteria. This approach enables early detection of valve malfunctions through continuous monitoring of system performance parameters, rather than relying on manual troubleshooting.

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A control method for air conditioning systems that enables automated diagnosis and repair of electronic expansion valve (EEP) issues through continuous monitoring of system parameters. The method employs a multi-branch system with parallel indoor units, each equipped with an electronic expansion valve and auxiliary transformer. The control system continuously monitors temperature changes in both the refrigerant and compressor circuits before and after compressor restarts, as well as during system shutdowns. This real-time analysis enables early detection of EEP faults, including stuck or malfunctioning valves, which can be automatically isolated and replaced. The system also monitors temperature changes during system startup, allowing for early detection of valve issues that may not be apparent during normal operation.

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Automatically detecting and controlling electronic expansion valve failure in air conditioning systems. The method monitors the expansion valve's operating parameters during normal operation, comparing the rate of change of indoor coil temperature and compressor discharge temperature. If the valve fails to maintain its normal operating characteristics, a diagnostic sequence is initiated, with the system automatically resetting the valve to its proper position. The method continuously monitors the valve's performance and provides alerts when it fails to meet expected operating parameters.

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Air-conditioning apparatus that detects switching failures in multiple valve positions. The apparatus monitors refrigerant flow through its four-way valve, first three-way valve, and second three-way valve. When a valve fails, the apparatus measures temperature changes in the discharge path, indoor pipe, and indoor air to detect abnormal refrigerant flow characteristics. This enables early detection of valve failures that prevent compressor breakdowns and motor overheating. The apparatus can perform heating, defrosting, and simultaneous heating-defrosting operations.

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A refrigeration cycle apparatus that more accurately detects valve abnormalities through temperature monitoring. The apparatus employs a unique temperature monitoring configuration that compares the temperatures measured by two temperature sensors: one located in the refrigerant path and another in the air path through the indoor heat exchanger. When the temperatures deviate, the system detects potential valve issues, including both expansion valve and bypass valve malfunctions, through this dual-sensor approach. This configuration enables more precise detection of valve anomalies compared to traditional single-sensor monitoring.

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Electronic expansion valve fault detection for one-to-many air conditioners by selectively throttling the refrigerant pipeline where the faulty valve is located. The method involves monitoring the operating parameters of the indoor units corresponding to the faulty valve, then adjusting the auxiliary valve's opening to redirect refrigerant flow through the faulty valve. This approach enables targeted valve replacement without requiring complete system shutdown.

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Detecting valve abnormalities in refrigeration cycles through advanced temperature monitoring. The system employs multiple temperature sensors to detect abnormal valve performance. The system operates in a controlled cycle where the compressor operates, the condenser functions, and the valves are closed. Temperature sensors monitor the refrigerant flow through the condenser, indoor heat exchanger, and bypass, while a pressure sensor tracks the expansion valve operation. When the difference between the condenser and bypass temperatures exceeds predetermined thresholds, or when the pressure sensor detects abnormal expansion valve operation, a notification is triggered to investigate valve issues.

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Control device for refrigeration systems with an electronic expansion valve that automatically detects and corrects valve operation anomalies. The device stores target values for physical quantities like temperature and pressure, and continuously monitors the valve's performance. When an anomaly is detected, the device sends commands to adjust the valve's operation. If the anomaly is resolved, the device performs a confirmation check to ensure normal operation. This approach eliminates unnecessary system shutdowns while maintaining continuous refrigeration operation.

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Reducing the risk of an abnormality generated in an expansion valve in a circuit. The device includes an outdoor unit, a flow dividing controller, and two indoor units.

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Fault detection for electronic expansion valves in air conditioning systems that prevents refrigerant leaks during shut-down. The method monitors the temperature differences across the refrigerant lines between the two indoor units, specifically between the liquid and gas lines. When the expansion valve fails to close completely, the system automatically shuts down the indoor unit with the malfunctioning valve. This approach ensures complete valve closure during shutdown, preventing refrigerant leaks and damage to the compressor.

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Air conditioner control method and device that enables early detection of electronic expansion valve failure through real-time temperature monitoring. The method measures the temperature difference between the indoor and outdoor units during both startup and shutdown phases, comparing the absolute values to a predefined threshold. If the difference exceeds the threshold, it indicates valve malfunction. This approach enables proactive maintenance by triggering alerts when the expansion valve's performance begins to degrade.

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A method and device for fault diagnosis of electronic expansion valves in air conditioning systems, which utilizes advanced data analysis to evaluate valve operation. The method compares the low-pressure pressure drop during compressor startup with a predetermined reference value to determine if the electronic expansion valve is functioning correctly. This comparison-based approach enables automated detection of abnormal valve behavior through continuous monitoring of pressure changes over time.

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A refrigeration cycle device that enables independent detection of electronic expansion valve abnormalities through a novel approach that accounts for the dynamic temperature variations of the refrigerant and the indoor environment. The device maintains the electronic expansion valve in an open state during normal operation, and when the indoor heat exchanger efficiency falls below a reference value, it triggers a notification of potential valve issues. This approach eliminates the temperature-based detection limitations of conventional systems by leveraging the dynamic temperature variations of both the refrigerant and the indoor environment.

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Fault detection method for electronic expansion valves in air conditioning systems that enables proactive maintenance through self-diagnostic capabilities. The method monitors the expansion valve's operation by controlling the indoor air conditioner to enter self-diagnostic mode when the valve is in an open position. During this diagnostic cycle, the system collects temperature data from the heat exchanger outlet. The method then compares this temperature data against predetermined threshold values to determine if the expansion valve is malfunctioning. This approach enables early detection of valve issues before they cause system performance degradation, allowing for targeted maintenance before system failure occurs.

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A refrigeration cycle device that enables precise detection of valve anomalies through a novel valve configuration. The device comprises a refrigeration cycle circuit with an electronic expansion valve and two solenoid valves for each indoor heat exchanger. The valve configuration includes a bypass path between the indoor heat exchanger and refrigerant flow switching device. An additional temperature sensor detects the air temperature entering the indoor heat exchanger, while a second temperature sensor monitors the refrigerant temperature. The device uses the air temperature to detect refrigerant flow anomalies, with the solenoid valves controlling the refrigerant flow. When the air temperature exceeds the refrigerant evaporation temperature, an electronic expansion valve or first solenoid valve is notified, while the second solenoid valve is used when the air temperature exceeds the refrigerant evaporation temperature. This configuration enables the device to detect valve anomalies through a single temperature sensor, rather than relying on separate temperature sensors for each valve type.

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Fault detection method for air conditioners that enables early detection of valve malfunctions through continuous monitoring of system parameters. The method operates the air conditioner at target operating conditions for a predetermined period, then continuously monitors pressure and exhaust temperature to determine if the valve is functioning correctly. If the system parameters do not match the target opening, the method detects the malfunction and initiates corrective action. This approach eliminates the need for intermittent checks and provides real-time feedback to prevent premature valve failure.

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Fault detection for air conditioner on/off valves using a novel configuration that integrates the valve with the compressor's auxiliary circuit. The detection assembly includes a valve that controls the compressor's enthalpy increase mode, with the valve's shut-off point connected to the compressor's enthalpy port and the valve's termination point connected to the compressor's auxiliary circuit outlet. This configuration enables the valve to monitor both its own operation and the compressor's performance through a single point of failure, eliminating the need for separate monitoring systems.

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Automatically detecting electronic expansion valve failure in air conditioners through continuous monitoring of the valve's operation. The method measures the initial and final air temperature differences when the valve is adjusted to its specified position, and detects deviations from the predetermined range when the valve exceeds it. This continuous monitoring enables early detection of valve failure through the valve's operational characteristics, rather than relying on intermittent fault detection methods.

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Fault detection for electronic expansion valves in air conditioners through real-time monitoring of low-voltage switch signals. The method enables accurate detection of expansion valve faults by analyzing the low-voltage switch's state changes in response to compressor operation.

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Early detection of electronic expansion valve failure in multi-line air conditioning systems through real-time monitoring of operating parameters. The method employs a centralized controller that continuously tracks system performance metrics, such as tube temperature, ambient temperature, power status, valve status, and operational history. When abnormal conditions are detected, the controller triggers an immediate fault detection and warning system that alerts maintenance personnel. This proactive approach enables rapid diagnosis and repair of electronic expansion valve issues, significantly improving maintenance efficiency compared to traditional manual inspection methods.

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Air conditioning system with intelligent expansion valve management that optimizes performance across all components. The system classifies expansion valves based on their operational significance, storing current values for each valve. When a valve's normal operating range is exceeded, it triggers specific control actions: if a valve's normal range is missed, it restricts operation; if a valve's normal range is exceeded and its stored value is within range, it restricts operation. This approach enables comprehensive monitoring of all expansion valves, preventing system-wide malfunctions while maintaining optimal performance during normal operation.

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Detecting linkage failures between internal throttle valves and shunt valves in multi-line HVAC systems. The method determines whether internal valves and corresponding shunt valves are malfunctioning by analyzing temperature differences between indoor units and their heat exchangers. When the system is in cooling mode, the method compares indoor unit temperatures with heat exchanger inlet and outlet temperatures to detect valve failures. When the system is in heating mode, it compares indoor unit temperatures with heat exchanger inlet temperatures to detect valve failures.

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Electronic expansion valve fault detection method and device for air conditioning systems to prevent compressor damage. The method monitors temperature differences between the air conditioner's internal and environmental temperatures during operation, and adjusts the electronic expansion valve's opening degree based on these temperature differences. If the temperature difference falls below a predetermined threshold, the valve is automatically opened to allow liquid refrigerant flow. Once the temperature difference exceeds this threshold, the valve is closed to prevent excessive liquid flow. This approach ensures reliable operation while preventing compressor damage from improper valve closure.

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Control device for electronic expansion valves in air conditioners that enables autonomous protection through real-time monitoring of valve operation. The device integrates a main control chip, a driving chip, and an electronic expansion valve, with the main control chip providing control signals to the driving chip. The driving chip operates the valve according to control signals and continuously monitors its coil state. The main control chip evaluates the coil status and determines valve operation anomalies. When an anomaly is detected, the device initiates maintenance procedures to prevent system failure.

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Automotive air conditioning system control method for electronic expansion valves that enables real-time fault detection and automatic system shutdown. The method monitors the actual superheat temperature of the expansion valve and compares it against predetermined threshold values. When the actual temperature exceeds the threshold, the system automatically shuts down the expansion valve to prevent damage from overheating. This approach enables precise control of the expansion valve while maintaining system reliability and safety.

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Electronic expansion valve detection method and apparatus for air conditioning systems that eliminates the need for internal pressure sensors while maintaining reliability. The detection method employs a temperature sensor positioned on the outside of the expansion valve's low-pressure pipe, allowing direct measurement of the valve's opening degree without requiring access to the refrigerant system. This eliminates the environmental concerns associated with traditional pressure sensors, which can introduce refrigerant into the system. The temperature sensor is designed to accurately measure the valve's opening state, enabling precise control signal verification. The system achieves reliable detection through the temperature sensor's direct measurement of the valve's operating conditions, rather than relying on pressure readings.

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Air conditioner electronic expansion valve fault detection method that enables proactive maintenance through continuous monitoring of temperature differences between inlet and outlet. The method employs a novel approach where the system continuously measures temperature deviations between the inlet and outlet streams until a predetermined threshold is reached. When the deviation exceeds this threshold, the system triggers a diagnostic cycle that repeatedly opens and closes the valve at specific operating points. This cycle is repeated multiple times, with the system continuously monitoring temperature differences between the inlet and outlet streams. If the deviation remains below the threshold, the system determines if the valve is malfunctioning and initiates diagnostic steps. The method provides an early warning system that enables proactive maintenance before potential issues escalate to more severe problems.

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Detecting electronic expansion valve faults in air conditioners through temperature monitoring. The method involves measuring the compressor discharge temperature to determine if the electronic expansion valve is functioning within its operating range. If the valve's discharge temperature exceeds a predetermined threshold, it indicates a potential fault. This approach eliminates the need for complex control chip adjustments, which can be unreliable in electronic expansion valve control systems.

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