Refrigeration circuit

Abstract

Provided is a refrigeration circuit including a compressor such as a compressor having a built-in motor, a condenser, a pressure reduction and expansion means, and an evaporator. The refrigeration circuit uses R1234yf as a refrigerant and provides therein a radical-capturing agent or a polymerization inhibitor. When the R1234yf as a new refrigerant is used and there is a possibility that radicals are formed, it is possible to prevent or suppress generation of radicals and prevent polymerization of R1234yf so that a target performance can be realized even when the new refrigerant is used.

1 . A refrigeration circuit comprising a compressor for compressing refrigerant, a condenser for condensing compressed refrigerant, a pressure reduction and expansion means for reducing in pressure and expanding condensed refrigerant, and an evaporator for evaporating pressure-reduced and expanded refrigerant, characterized in that R1234yf is used as a refrigerant for said refrigeration circuit, and a radical-capturing agent or a polymerization inhibitor is provided in said refrigeration circuit. 
     
     
         2 . The refrigeration circuit according to  claim 1 , wherein said compressor is an electric compressor having a built-in motor for driving said compressor. 
     
     
         3 . The refrigeration circuit according to  claim 1 , wherein said compressor is a compressor driven by an external drive source. 
     
     
         4 . The refrigeration circuit according to  claim 1 , wherein said compressor is a compressor comprising first compression mechanism and second compression mechanism, wherein said first compression mechanism is driven by an external drive source and said second compression mechanism is driven by a built-in motor, selectively or simultaneously. 
     
     
         5 . The refrigeration circuit according to  claim 1 , wherein said radical-capturing agent or said polymerization inhibitor is provided in said refrigeration circuit by being provided on a surface of a member for forming a circuit inner surface which is brought into contact with said refrigerant. 
     
     
         6 . The refrigeration circuit according to  claim 5 , wherein said circuit inner surface-forming member brought into contact with said refrigerant is a member provided in said compressor. 
     
     
         7 . The refrigeration circuit according to  claim 5 , wherein said radical-capturing agent or polymerization inhibitor is compounded in a material of said circuit inner surface-forming member which is brought into contact with said refrigerant. 
     
     
         8 . The refrigeration circuit according to  claim 5 , wherein said radical-capturing agent or polymerization inhibitor agent is provided on a surface of said circuit inner surface-forming member which is brought into contact with said refrigerant, by coating. 
     
     
         9 . The refrigeration circuit according to  claim 1 , wherein said radical-capturing agent or polymerization inhibitor is provided in said refrigeration circuit by being contained in said refrigerant. 
     
     
         10 . The refrigeration circuit according to  claim 1 , wherein said refrigeration circuit is used in an air conditioning system for vehicles.