System for controlling flow rate of refrigerant

摘要

A system for controlling the flow rate of a refrigerant for refrigeration cycles which comprises an electronic expansion valve disposed at the inlet of an evaporator and a controller for controlling the opening-closing movement of the valve. The controller comprises a calculating unit for comparing the degree of superheat of the refrigerant measured at the evaporator with a preset degree of superheat and feeding a valve opening adjusting signal to the valve according to the value obtained by the comparison, and a valve full-closing signal generator for comparing the measured temperature of the space to be cooled with a preset temperature and feeding a valve full-closing signal to the valve based on the value obtained from the comparison of temperatures, in preference to the opening adjusting signal.