Abstract: An electronic expansion valve (EEV) is employed in refrigeration systems to regulate the flow of refrigerant through an evaporator. The position of the EEV is controlled through a first control loop that generates a first position signal based on superheat feedback associated with the refrigeration system, and a second control loop that generates a second position signal based on pressure feedback associated with the refrigeration system. The larger of the first position signal and the second position signal is selected to control the position of the EEV value, and the selected position signal is provided in feedback to both the first control loop and the second control loop.

Abstract: A defrost cycle time of an aircraft vapor cycle refrigeration system is adaptively controlled. A pressure of refrigerant at an inlet of a compressor of the vapor cycle refrigeration system is sensed. A defrost cycle of the vapor cycle refrigeration system is initiated in response to the sensed pressure being less than a threshold pressure. The defrost cycle is terminated upon expiration of the defrost cycle time. The defrost cycle time is based upon a time duration of the cooling cycle.

Abstract: Adaptable evaporator defrost logic is employed in a refrigeration system to detect a build-up of ice on the evaporator. In response to the detected build-up of ice, a defrost operation is initiated that includes decreasing the speed of the compressor. At the end of the defrost operation, the adaptable evaporator defrost logic determines whether the defrost operation was a success. If the defrost operation was a success, then normal operation is resumed. If the defrost operation was not a success, then the defrost operation is modified by turning the compressor off and extending a duration of the defrost operation.

Abstract: Adaptable evaporator defrost logic is employed in a refrigeration system to detect a build-up of ice on the evaporator. In response to the detected build-up of ice, a defrost operation is initiated that includes decreasing the speed of the compressor. At the end of the defrost operation, the adaptable evaporator defrost logic determines whether the defrost operation was a success. If the defrost operation was a success, then normal operation is resumed. If the defrost operation was not a success, then the defrost operation is modified by turning the compressor off and extending a duration of the defrost operation.

Abstract: An electronic expansion valve (EEV) is employed in refrigeration systems to regulate the flow of refrigerant through an evaporator. The position of the EEV is controlled through a first control loop that generates a first position signal based on superheat feedback associated with the refrigeration system, and a second control loop that generates a second position signal based on pressure feedback associated with the refrigeration system. The larger of the first position signal and the second position signal is selected to control the position of the EEV value, and the selected position signal is provided in feedback to both the first control loop and the second control loop.