Abstract: Disclosed is a refrigeration circuit in which a scroll compressor is used as a compressor, an unsaturated fluorinated hydrocarbon refrigerant is used as a refrigerant, and an ether-based lubricant such as a polyalkylene glycol is used as a refrigeration machine oil, and wherein a wax-like solid material, which causes clogging of the refrigeration circuit or deterioration of the refrigeration performance, is prevented from being generated. Specifically, a wax-like solid material is prevented from being generated in a refrigeration circuit by adding a lubricant type component having no polyoxyalkylene structure such as an ester-based lubricant, an alcohol-based friction modifier, an olefin-based friction modifier, a polyolefin-based lubricant, an alkyl aromatic lubricant or a silicone-based lubricant, or a metal deactivation agent such as benzotriazole to an ether-based lubricant such as a polyalkylene glycol.

Abstract: A resin material for a refrigeration circuit comprising a compressor for a refrigerant, a condenser, a depressurizing/expanding means, and an evaporator, the resin material being disposed in the refrigeration circuit at such a position that the resin part comes into direct contact with the refrigerant. The resin material is characterized in that when R1234yf is used as the refrigerant, the resin material has chemical resistance at least to the refrigerant itself or ingredients generated by the decomposition of the refrigerant. This resin material is prevented from undergoing a chemical reaction with the refrigerant R1234yf itself or ingredients generated by the decomposition thereof. Consequently, refrigerant leakage caused by the decomposition of the resin material is prevented. Furthermore, clogging and a decrease in refrigerating performance, which are caused by the circulation of an undesirable compound through the circuit, are prevented.

Abstract: A refrigeration circuit provided with a scroll compressor for compressing a refrigerant, characterized in that R1234yf is used as the refrigerant and a polyol ester is used as a lubricating oil for the refrigeration circuit. In this refrigeration circuit, an undesirable reaction product can be prevented from accumulating. The refrigeration circuit hence is reduced in environmental burden and has the same operating stability as in conventional ones.