Intelligent Control to Reduce Superheat Hunting and Optimize Evaporator Performance in Container Refrigeration

Fuzzy logic is applied to the control of superheat in the evaporator of a commercial container refrigeration system using an electronic expansion valve and adaptive superheat control algorithm has been devised to enhance evaporator performance. Superheat hunting has been reduced, and an improvement of 7.5 % in the coefficient of performance of the refrigeration system can be realized using adaptive superheat control as compared to constant superheat control strategy. Intelligent control gives a more stable superheat control in the initial evaporator pull-down and effects a faster pulldown rate of the temperature of the container box.