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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Vehicle air conditioner with automatic failure location detection. The system monitors refrigerant circuit pressure and temperature to identify control valve failures. When a control valve fails, the system switches to a failure location detection mode, which continues operating in the failed mode until the valve is located. This approach eliminates the need for manual diagnosis and maintenance, allowing the vehicle to continue operating while the failed valve is isolated.

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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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