REFRIGERATING CYCLE APPARATUS AND METHOD FOR OPERATING THE SAME

摘要

A refrigerating cycle apparatus and a method of operating the same are provided. For a refrigerating cycle having a plurality of compressors connected in series for multi-stage compression, an inner space of each compressor and a pipe of the refrigerating cycle may be connected via an oil collection pipe, and oil may be discharged into the refrigerating cycle by pressure reversal during a pressure balancing operation, so as to allow the discharged oil to be collected into a high-stage compressor or a low-stage compressor. Accordingly, an amount of oil may be uniformly maintained in each of the plurality of compressors to prevent losses due to friction and/or increases in power consumption due to a lack of oil in one or more of the compressors. The structure of a device and pipes for performing oil balancing between the compressors may be simplified to enhance efficiency of the compressors.

主权项

1. A method for operating a refrigerating cycle apparatus having a low-stage compressor and a high-stage compressor connected to each other in series, and a refrigerant switching valve connected to a discharge side of the high-stage compressor and having a low-stage side outlet connected to a low-stage side evaporator and a high-stage side outlet connected to a high-stage side evaporator, with the low-stage side evaporator connected to a suction side of the low-stage compressor and the high-stage side evaporator connected to a suction side of the high-stage compressor, the method comprising:
determining that oil balancing is required between the low-stage compressor and the high-stage compressor; and performing an oil balancing operation and transferring oil from one of the low-stage or the high-stage compressor to the other of the low-stage or the high-stage compressor, the one of the low-stage or the high-stage compressor containing more oil than the other of the low-stage or the high-stage compressor, wherein the performing of the oil balancing operation comprises driving both the low-stage compressor and the high-stage compressor for a predetermined period of time, with at least the low-stage side outlet of the refrigerant switching valve open.