Heat transfer methods, systems and compositions

Abstract

Disclosed are refrigerants comprising at least about 97% by weight of a blend of three compounds, said blend consisting of: from about 40% by weight to about 49% by weight difluoromethane (HFC-32), from about 6% by weight to about 12% by weight pentafluoroethane (HFC-125), from about 33% by weight to about 40% by weight trifluoroiodomethane (CF 3 I); and from about 2% by weight to about 12% by weight of trans 1,3,3,3-tetrafluoropropene (trans HFO-1234ze), wherein the percentages are based on the total weight of the three compounds in the blend, and systems and method using same.

1 . A heat transfer composition comprising at least about 40% by weight of refrigerant and a stabilizer for said refrigerant, wherein said refrigerant comprises at least about 97% by weight of a blend of the following four compounds, with the following percentages being based on the total weight of the following four compounds:
 from about 40% by weight to about 49% by weight difluoromethane (HFC-32),   from about 6% by weight to about 12% by weight pentafluoroethane (HFC-125),   from about 33% by weight to about 40% by weight trifluoroiodomethane (CF 3 I); and   from about 2% by weight to about 12% by weight of trans 1,3,3,3-tetrafluoropropene (trans HFO-1234ze), provided that the refrigerant is substantially free of CO2.   
     
     
         2 . The heat transfer composition of  claim 1  wherein together said HFC-32, said HFC-125, said CF3I and said transHFO-1234ze comprise at least about 98.5% by weight of said refrigerant. 
     
     
         3 . The heat transfer composition of  claim 1  wherein together said HFC-32, said HFC-125, said CF3I and said transHFO-1234ze comprise at least about 99.5% by weight of said refrigerant. 
     
     
         4 . The heat transfer composition of  claim 1  wherein said refrigerant comprises:
 from about 46.5% by weight to about 48.5% by weight difluoromethane (HFC-32), 
 from about 10.5% by weight to about 12% by weight pentafluoroethane (HFC-125), 
 from about 34.5% by weight to about 36.5% by weight trifluoroiodomethane (CF 3 I); and 
 from about 2% by weight to about 5% by weight of trans 1,3,3,3-tetrafluoropropene (trans HFO-1234ze). 
 
     
     
         5 . The heat transfer composition of  claim 1  wherein said refrigerant comprises:
 about 47.5% by weight difluoromethane (HFC-32), 
 about 12% by weight pentafluoroethane (HFC-125), 
 about 36.5% by weight trifluoroiodomethane (CF 3 I); and 
 about 4% by weight of trans 1,3,3,3-tetrafluoropropene (trans HFO-1234ze). 
 
     
     
         6 . The heat transfer composition as claimed in  claim 1 , wherein the refrigerant comprises greater than 70% by weight of the composition. 
     
     
         7 . The heat transfer composition of  claim 1  wherein said stabilizer is selected from a diene based compound, a phosphorous compound, a nitrogen compound, an epoxide and combinations of two or more of these. 
     
     
         8 . The heat transfer composition of  claim 6  wherein the stabilizer comprises an epoxide selected from the group consisting of aromatic epoxides, alkyl epoxides, alkyenyl epoxides and combinations of two or more of these. 
     
     
         9 . The heat transfer composition of  claim 8  further comprising a lubricant selected from the group consisting of polyol esters (POEs), polyalkylene glycols (PAGs), PAG oils, silicone oils, mineral oil, alkylbenzenes (ABs) and poly(alpha-olefin) (PAO). 
     
     
         10 . The heat transfer composition of  claim 9  wherein the lubricant is selected from polyol esters (POEs) and polyalkylene glycols (PAGs). 
     
     
         11 . The heat transfer composition of  claim 10  wherein the lubricant is present in the heat transfer composition in an amount of from about 10 to about 60% by weight. 
     
     
         12 . The heat transfer composition of  claim 11  wherein said refrigerant has a Global Warming Potential (GWP) of not greater than 750. 
     
     
         13 . A method of cooling in a heat transfer system comprising an evaporator, a condenser and a compressor, the process comprising:
 i) compressing a fluid comprising a lubricant, a stabilizer and a refrigerant, said refrigerant comprising:   from about 40% by weight to about 49% by weight difluoromethane (HFC-32),   from about 6% by weight to about 12% by weight pentafluoroethane (HFC-125),   from about 33% by weight to about 40% by weight trifluoroiodomethane (CF 3 I); and   from about 2% by weight to about 12% by weight of trans 1,3,3,3-tetrafluoropropene (trans HFO-1234ze), provided that together said HFC-32, said HFC-125, said CF3I and said transHFO-1234ze comprise at least about 97% by weight of said refrigerant;   (ii) condensing said refrigerant; and   iii) evaporating the refrigerant in the vicinity of the body or article to be cooled;   wherein the evaporator temperature of the heat transfer system is in the range of from about −40° C. to about −10° C.   
     
     
         14 . The method of  claim 13  wherein the heat transfer system is an air conditioning system. 
     
     
         15 . The method of  claim 14  wherein the air conditioning system is selected from an automobile air conditioning system, a chiller, a residential air conditioning system, a residential heat pump, a residential air to water heat pump/hydronic system, an industrial air conditioning system and a commercial air conditioning system. 
     
     
         16 . A method of replacing an existing refrigerant contained in a heat transfer system comprising removing at least a portion of said existing refrigerant from said system, said existing refrigerant being R-410A and replacing at least a portion of said existing refrigerant by introducing into said system a stabilizer and a refrigerant, said refrigerant comprising:
 from about 40% by weight to about 49% by weight difluoromethane (HFC-32),   from about 6% by weight to about 12% by weight pentafluoroethane (HFC-125),   from about 33% by weight to about 40% by weight trifluoroiodomethane (CF 3 I); and   from about 2% by weight to about 12% by weight of trans 1,3,3,3-tetrafluoropropene (trans HFO-1234ze), provided that together said HFC-32, said HFC-125, said CF3I and said transHFO-1234ze comprise at least about 97% by weight of said refrigerant.   
     
     
         17 . The method of  claim 16  wherein the heat transfer system is an air conditioning system. 
     
     
         18 . The method of  claim 17  wherein the air conditioning system is selected from an automobile air conditioning system, a chiller, a residential air conditioning system, a residential heat pump, a residential air to water heat pump/hydronic system, an industrial air conditioning system and a commercial air conditioning system. 
     
     
         19 . The method of  claim 16  wherein said stabilizer comprises an epoxide selected from the group consisting of aromatic epoxides, alkyl epoxides, alkyenyl epoxides and combinations of two or more of these. 
     
     
         20 . The method of  claim 16  wherein said stabilizer comprises an epoxide selected from the group consisting of aromatic epoxides, alkyl epoxides, alkyenyl epoxides and combinations of two or more of these.