Patent ID: 8789389

Claim:
An intermediate heat exchanger used in an air conditioner including a compressor, a condenser for cooling refrigerant compressed by the compressor, a pressure reducer for reducing pressure of the refrigerant cooled by the condenser, and an evaporator for evaporating the refrigerant of reduced pressure, the intermediate heat exchanger exchanging heat between refrigerant of high pressure flowing out of the condenser and refrigerant of low pressure flowing out of the evaporator, wherein the intermediate heat exchanger is composed of a double tube which includes an outer tube and an inner tube disposed inside the outer tube with a clearance formed therebetween, the clearance formed between the outer tube and the inner tube serving as a high-temperature-side refrigerant passage through which the refrigerant of high pressure flowing out of the condenser flows, and the interior of the inner tube serving as a low-temperature-side refrigerant passage through which the refrigerant of low pressure flowing out of the evaporator flows; and a liquid reservoir communicating with the high-temperature-side refrigerant passage of the double tube, the liquid reservoir storing the refrigerant of high pressure, flowing out of the condenser, in a stage before the pressure of the refrigerant is reduced by the pressure reducer, and separating liquid-phase refrigerant and gas-phase refrigerant from each other; and the outer tube of the double tube has a refrigerant inlet and a refrigerant outlet which communicate with the high-temperature-side refrigerant passage, wherein, at an intermediate position between the refrigerant inlet and the refrigerant outlet, the refrigerant of high pressure enters the liquid reservoir from the high-temperature-side refrigerant passage of the double tube, and returns from the liquid reservoir to the high-temperature-side refrigerant passage.