Start-up control method for refrigeration cycle apparatus and refrigeration cycle control apparatus using the same

Abstract

In a refrigeration cycle apparatus having an expansion mechanism, a method to swiftly generate a pressure difference upstream and downstream of the expansion mechanism of, thereby enhancing the starting performance of the refrigeration cycle apparatus. The apparatus has a compression mechanism, a utilizing-side heat exchange, an expansion mechanism for recovering power, and a heat source-side heat exchanger. The revolution number of the heat source fluid transfer means is made smaller than a target revolution number or the heat source fluid transfer means is stopped during a predetermined time after the compression mechanism is started. When the compression mechanism is started, the pressure difference can be generated upstream and downstream of the expansion mechanism for a short time, the operation of the expansion mechanism does not become unstable, vibration and noise can be prevented, and the refrigeration cycle apparatus can swiftly be started.

1 . A control method of a refrigeration cycle apparatus comprising at least a compression mechanism, a heat source-side heat exchanger, an expansion mechanism from which power is recovered by a power generator, a utilizing-side heat exchanger, and a pre-decompressor for decompressing a refrigerant flowing into said expansion mechanism, wherein after said compression mechanism is started, an opening of said pre-decompressor is reduced to a value smaller than an opening at the time of normal operation for a predetermined time (T), and after said predetermined time (T) is elapsed, the opening of said pre-decompressor is set to a target opening. 
   
   
       2 . The control method of the refrigeration cycle apparatus according to  claims 1 , wherein said expansion mechanism is a scroll type expansion mechanism. 
   
   
       3 . A refrigeration cycle apparatus using the control method according to  claim 1 .