REFRIGERATION CYCLE APPARATUS AND METHOD FOR OPERATING SAME

摘要

Provides is a refrigeration cycle apparatus wherein power is always recovered over a wide operation range even when it is difficult to optimally adjust the high pressure-side pressure due to the restriction for maintaining a constant density ratio, and a high-efficiency operation can be realized. In a refrigeration cycle apparatus (100), a control device (83) changes either one or both of the apertures of an intermediate pressure bypass valve (9) and a preliminary expansion valve (6) on the basis of the density ratio in an actual operation state, said density ratio being obtained from the density of refrigerant introduced to an expansion machine (7) and the density of refrigerant introduced to a subsidiary compressor (2), and the design volume ratio which is assumed when the apparatus is designed and which is obtained from the stroke volume of the subsidiary compressor (2), the stroke volume of the expansion machine (7), and the ratio of the flow rate of refrigerant introduced to the subsidiary compressor (2). Thus, the high pressure-side pressure is adjusted.