COOLING SYSTEM AND ITS CONTROL METHOD

摘要

PURPOSE: A refrigeration system and method for controlling operation of refrigeration system is provided to achieve an improved cooling efficiency by maintaining constant amount of residual oil within the compressor and allowing cooling and lubrication operation of the compressor to be smoothly performed. CONSTITUTION: A refrigeration system comprises an oil separator(35) mounted between a compressor(30) and a condenser(31) and which returns the separated oil to the compressor; a return pipe(36) for guiding oil from the oil separator to the compressor; an oil tank(40) mounted at the return pipe for storage of oil; an open/shut-off valve(41) mounted between the oil tank and the compressor; a by-pass pipe(45) arranged at the refrigerant pipe connecting the oil tank, an evaporator(32) and the compressor; a motor-operated expansion valve(42) mounted at the by-pass pipe and which adjust pressure of the oil tank; an oil sensing unit(20) for sensing the amount of oil within the compressor; and a control unit for controlling operation of the open/shut-off valve in accordance with the signal output from the oil sensing unit.