Refrigeration cycle apparatus

Abstract

An object of the present invention is to provide a refrigeration cycle apparatus having a compressor that is not easily heated to high temperature by sliding heat and thus higher in reliability. Provided is a refrigeration cycle apparatus having a cost-effective compressor in the configuration in which a piston 9 eccentrically revolving, as driven by a shaft 4, is placed in a cylinder 6 and the circular terminal region 10 a of a vane 10 partitioning the cylinder 6 into a suction chamber 12 and a compression chamber 13 is connected slidably to the external surface of the piston 9 in surface contact, which can reduce the sliding heat and is thus resistant to deterioration in reliability by reaction of the operating refrigerant.

1 . A refrigeration cycle apparatus, comprising:
 a rotary compressor, using a single refrigerant of a hydrofluoroolefin having a carbon-carbon double bond or a mixed refrigerant at least containing the hydrofluoroolefin and additionally hydrofluorocarbon having no double bond as an operating refrigerant and having a motor and a compression mechanism unit driven by a rotor of the motor in a tightly sealed container, the compression mechanism unit having a piston eccentrically revolving, as driven by a shaft, in a cylinder, the terminal region of a vane, which partitions the cylinder into a suction chamber and a compression chamber, being slidably connected to the external surface of the piston;   a condenser cooling the refrigerant gas pressurized, as compressed by the compressor;   a throttling mechanism depressurizing the high-pressure refrigerant liquefied by the condenser; and   a vaporizer gasifying the depressurized liquid refrigerant, wherein   the rotary compressor, the condenser, the throttling mechanism and the vaporizer are connected to each other with piping.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein the terminal region of the rotary compressor vane and the external surface of the piston are slidably connected to each other, by the circular terminal region of the vane and an arc-shaped slot on the external surface of the piston. 
     
     
         3 . The refrigeration cycle apparatus according to  claim 2 , wherein the angle of connection of the arc-shaped slot is 180° or more. 
     
     
         4 . The refrigeration cycle apparatus according to  claim 1 , wherein the operating refrigerant is a two- or three-component mixed refrigerant containing a hydrofluoroolefin tetrafluoropropene (HFO1234yf) as primary component, and one or more hydrofluorocarbon having no double bond and selected from the group consisting of difluoromethane, pentafluoroethane and tetrafluoroethane, the hydrofluorocarbon being added at a rate to give a global warming potential of 5 or more and 750 or less. 
     
     
         5 . The refrigeration cycle apparatus according to  claim 1 , wherein the refrigeration oil is a synthetic oil containing an oxygen-containing compound selected from the group consisting of polyoxyalkylene glycols, polyvinylethers, copolymers of poly(oxy)alkylene glycols or the monoethers thereof and polyvinylether, polyol esters and polycarbonates as a principal component or a synthetic oil containing an alkyl benzene or an α-olefin as a principal component.