Hamilton Sundstrand Corporation

Tejendra Patel

Tony Ho

Jeffrey Ernst

Richard Rusich

Bruce R Schroder

Robert M DeRoy

Anson Stark Coolidge

Kokjovi Coussey

Kodjovi Coussey

Young K Park

Coussey Kodjovi

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.

Control algorithm for electronic expansion valve modulation

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.

Adaptable evaporator defrost logic for an aircraft

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Ellington, CT, United States of America

Tejendra Patel