Patent ID: 8650904

Claim:
An ejector-type refrigerant cycle device comprising: a compressor configured to compress and discharge refrigerant; a radiator disposed to cool the refrigerant discharged from the compressor; an ejector that includes a nozzle portion in which the refrigerant flowing from the radiator is decompressed, a refrigerant suction port from which refrigerant is drawn by a high-speed refrigerant jetted from the nozzle portion, and a pressure increasing portion in which the refrigerant jetted from the nozzle portion and the refrigerant drawn from the refrigerant suction portion are mixed and pressurized; a suction side evaporator disposed to evaporate the refrigerant to be drawn into the refrigerant suction port of the ejector; a discharge capacity control portion configured to control a refrigerant discharge capacity of the compressor; a high pressure detector configured to detect a physical amount relative to a pressure of a high-pressure refrigerant in the refrigerant cycle; an evaporator temperature detector configured to detect a physical amount relative to a refrigerant evaporation temperature in the suction side evaporator; and a calculation portion configured to calculate a refrigerant evaporation pressure in the suction side evaporator based on a detection value of the evaporator temperature detector, wherein the discharge capacity control portion increases the refrigerant discharge capacity of the compressor in accordance with an increase of a requirement capacity required in a refrigerant cycle of a general operation, when the requirement capacity is larger than a standard value, when the requirement capacity required in the refrigerant cycle is equal to or smaller than the standard value, the discharge capacity control portion controls the refrigerant discharge capacity of the compressor to be switched alternately between a high capacity operation in which the refrigerant discharge capacity of the compressor is larger than a predetermined discharge capacity that is determined at the standard value of the requirement capacity in the general operation, and a low capacity operation in which the refrigerant discharge capacity of the compressor is lower than the predetermined discharge capacity; and the discharge capacity control portion determines that the requirement capacity required in the refrigerant cycle is equal to or smaller than the standard value when a pressure difference between a detection value of the high pressure detector and the refrigerant evaporation pressure in the suction side evaporator is smaller than a predetermined value.