VALVE CONTROL FOR OPTIMUM PERFORMANCE IN COMPRESSION REFRIGERATION CYCLES

A performance optimization system has been studied for refrigeration p lants based on vapor compression cycles. The water temperature at the evaporator exit is maintained at the requested value when the refriger ation capacity varies. Minimum power consumption is also achieved. The method is based on the calculation of valve opening set point law. Va lve openings are related to the external quantities: water mass flow i n the condenser and evaporator, temperature of the water at the conden ser inlet, compressor and electric motor serviceability, fouling of he at exchangers, etc. Results of an investigation carried out on a 200 k W refrigeration capacity plant are given and discussed.