REFRIGERATING CIRCUIT USING CLUTCHLESS VARIABLE CAPACITY COMPRESSOR

摘要

PURPOSE:To sufficiently cool and lubricate even at the time of no necessity of cooling by providing a capacity control valve for regulating a cranking pressure in response to a suction system pressure in a supply passage, providing a switching valve in a conduit from an expansion valve to an evaporator, and providing a supply conduit with a throttle for connecting the conduit between the switching valve and the expansion valve to a crank room. CONSTITUTION:A capacity control valve 50 disposed in a supply passage 51 for connecting a discharge chamber 31 to a crank chamber 5 regulates the crank chamber pressure when the pressure of a suction chamber 30 decreases from a set pressure to always hold the suction chamber pressure constant. A solenoid operating valve (two-port normal open switching valve) 105 is disposed at a conduit P4 from the valve 103 to an evaporator 104, and a conduit P4 between the valve 105 and the valve 103 is always connected to the crank room of a compressor 100 via a supply conduit P6 branched from the conduit P4. The sensor of the conduit P6 is connected to the room 5 via a throttle F1.