Refrigeration Circuit and Method for Improving Same

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.

1 . A refrigeration circuit provided with a scroll compressor as a compressor for compressing a refrigerant, wherein said refrigerant contains an unsaturated fluorinated hydrocarbon refrigerant as a part or the whole thereof, a refrigeration machine oil comprises an ether-based lubricant having a polyoxyalkylene structure, and said ether-based lubricant contains one or more selected from a lubricant type component having no polyoxyalkylene structure and a metal deactivation agent. 
     
     
         2 . A method for improving a refrigeration circuit provided with a scroll compressor as a compressor for compressing a refrigerant, wherein, by a condition where said refrigerant contains an unsaturated fluorinated hydrocarbon refrigerant as a part or the whole thereof, a refrigeration machine oil comprises an ether-based lubricant having a polyoxyalkylene structure, and said ether-based lubricant contains one or more selected from a lubricant type component having no polyoxyalkylene structure and a metal deactivation agent, decomposition of said unsaturated fluorinated hydrocarbon refrigerant caused by operation of said compressor and generation of a polymerized paraffin originating from polymerization of a polymerizable decomposed substance are prevented. 
     
     
         3 . The refrigeration circuit according to  claim 1 , wherein said unsaturated fluorinated hydrocarbon refrigerant is an unsaturated fluorinated hydrocarbon refrigerant having a group of CH 2 ═CH— or CH 2 ═CF— at an end of a molecule. 
     
     
         4 . The refrigeration circuit according to  claim 1 , wherein said unsaturated fluorinated hydrocarbon refrigerant is at least one of HFO1234yf and HFO1234ze. 
     
     
         5 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an ester-based lubricant. 
     
     
         6 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an ester-based lubricant comprising a polyol ester derived from a polyol and a univalent aliphatic acid. 
     
     
         7 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an alcohol-based friction modifier. 
     
     
         8 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an alcohol-based friction modifier comprising an aliphatic polyol having a carbon number in a range of 2 to 25. 
     
     
         9 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an olefin-based friction modifier. 
     
     
         10 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an olefin-based friction modifier comprising an olefin having a carbon number in a range of 10 to 18. 
     
     
         11 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is a polyolefin-based lubricant comprising a poly-α-olefin. 
     
     
         12 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an alkyl aromatic lubricant. 
     
     
         13 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is an alkyl aromatic-based lubricant selected from an alkyl benzene and an alkyl naphthalene. 
     
     
         14 . The refrigeration circuit according to  claim 1 , wherein said lubricant type component is a silicone-based lubricant. 
     
     
         15 . The refrigeration circuit according to  claim 1 , wherein said metal deactivation agent is a benzotriazole-based component. 
     
     
         16 . The refrigeration circuit according to  claim 1 , wherein said ether-based lubricant contains an acid capturing agent. 
     
     
         17 . The refrigeration circuit according to  claim 1 , wherein said ether-based lubricant contains an epoxy alkane having a carbon number in a range of 8 to 25 as an acid capturing agent.