Multi-stage compressing refrigeration device and refrigerator using the device

Abstract

There is disclosed a multi-stage compressing refrigeration device for multi-stage compressing a refrigerant using a plurality of compressing means. Its object is to enhance reliability, intend to reduce input and improve refrigeration effect, and to enhance efficiency. In the multi-stage compressing refrigeration device, low-stage compressing means and high-stage compressing means, a condenser, first expanding means, an intermediate evaporator, second expanding means and a main evaporator constitute a refrigeration cycle. The refrigerant flowing out of the condenser is branched into one refrigerant passed to the intermediate evaporator via the first expanding means and the other refrigerant passed to the main evaporator via the second expanding means. Heat exchange is performed between the refrigerant flowing into the second expanding means and the intermediate evaporator. Additionally, the refrigerant flowing out of the main evaporator is sucked by the low-stage compressing means, and the refrigerant flowing out of the intermediate evaporator is sucked by the high-stage compressing means together with the refrigerant discharged from the low-stage compressing means.