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 38% by weight to about 48% 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 41% by weight trifluoroiodomethane (CF 3 I) and from about 2% by weight to about 16% by weight 2,3,3,3-tetrafluoropropene (HFO-1234yf) wherein the percentages are based on the total weight of the three compounds in the blend, and methods and systems which use same.

1 . A refrigerant comprising at least about 97% by weight of a blend of three compounds, said blend consisting of:
 from about 38% by weight to about 48% 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 41% by weight trifluoroiodomethane (CF 3 I) and   from about 2% by weight to about 16% by weight 2,3,3,3-tetrafluoropropene (HFO-1234yf)   wherein the percentages are based on the total weight of the three compounds in the blend.   
     
     
         2 . The refrigerant of  claim 1  wherein said blend consists of:
 from about 46% by weight to about 48% by weight difluoromethane (HFC-32), 
 from about 11% by weight to about 12% by weight pentafluoroethane (HFC-125), 
 from about 34% by weight to about 36% by weight trifluoroiodomethane (CF 3 I) and 
 from about 5% by weight to about 7% by weight 2,3,3,3-tetrafluoropropene (HFO-1234yf) 
 wherein the percentages are based on the total weight of the three compounds in the blend. 
 
     
     
         3 . The refrigerant of  claim 1  wherein said blend consists of:
 about 47% by weight difluoromethane (HFC-32), 
 about 12% by weight pentafluoroethane (HFC-125), 
 about 35% by weight trifluoroiodomethane (CF 3 I) and 
 about 6% by weight 2,3,3,3-tetrafluoropropene (HFO-1234yf) 
 wherein the percentages are based on the total weight of the three compounds in the blend. 
 
     
     
         4 . The refrigerant of  claim 1  wherein the refrigerant comprises at least about 98.5% by weight of said blend. 
     
     
         5 . The refrigerant of  claim 1  wherein the refrigerant comprises at least about 99.5% by weight of said blend. 
     
     
         6 . The refrigerant of  claim 1  wherein the refrigerant consists essentially of said blend. 
     
     
         7 . The refrigerant of  claim 1  wherein the refrigerant consists of said blend. 
     
     
         8 . The refrigerant of  claim 1  wherein the weight ratio of (HFC-32+HFO-1234yf):(CF3I+HFC-125) is from greater than about 1:1 to less than 1.2:1. 
     
     
         9 . The refrigerant of  claim 1  wherein the weight ratio of (HFC-32+HFO-1234yf):(CF3I+HFC-125) is from greater than about 1.1:1 to about 1.18:1. 
     
     
         10 . The refrigerant of  claim 1  wherein the weight ratio of HFC-32:HFC-125 from greater than 3.5:1 to about 4:1, preferably from about 3.8:1 to about 3.9:1.1. 
     
     
         11 . A heat transfer composition comprising the refrigerant of  claim 1 . 
     
     
         12 . The heat transfer composition of  claim 11 , wherein the refrigerant comprises greater than 70% by weight of the heat transfer composition. 
     
     
         13 . The heat transfer composition of  claim 12  further comprising a stabilizer selected from a diene based compound, or a diene based compound and a phosphorous compound, and/or a nitrogen compound and/or a phenol compound. 
     
     
         14 . The heat transfer composition of  claim 13  wherein the stabilizer composition comprises a diene based compound and a phosphorous compound wherein said phosphorous compound is a phosphite compound selected from diaryl phosphite, dialkyl phosphite, triaryl phosphite and/or trialkyl phosphite. 
     
     
         19 . The heat transfer composition of  claim 13  wherein the stabilizer composition comprises farnesene and diphenyl phosphite. 
     
     
         20 . A heat transfer composition comprising a refrigerant as claimed in  claim 1  and a stabilizer composition, wherein the stabilizer composition consists of BHT in an amount of from about 0.001% by weight to about 5% by weight. 
     
     
         21 . A heat transfer composition comprising a refrigerant as claimed in  claim 1  and a stabilizer composition, wherein the stabilizer composition comprises farnesene, diphenyl phosphite and BHT. 
     
     
         22 . The heat transfer composition of  claim 21  further comprising a lubricant selected from the group consisting of polyol esters (POEs), polyalkylene glycols (PAGs), PAG oils, silicone oils, mineral oil, alkylbenzenes (ABs), polyvinyl ethers (PVE) and poly(alpha-olefin) (PAO). 
     
     
         23 . The heat transfer composition of  claim 22  wherein the lubricant is a polyol ester (POE). 
     
     
         24 . The heat transfer composition of  claim 1  wherein said refrigerant has a Global Warming Potential (GWP) of not greater than 750. 
     
     
         25 . The method as claimed in  claim 24  wherein the heat transfer system is an air conditioning system. 
     
     
         26 . The method as claimed in  claim 25  wherein the air conditioning system is a mobile air conditioning system. 
     
     
         27 . The method as claimed in  claim 26  wherein the air conditioning system is a residential air-conditioning system (with an evaporator temperature in the range of about 0 to about 10° C., particularly about 7° C. for cooling and/or in the range of about −30 to about 50° C., particularly about 0.5° C. for heating), particularly a residential air conditioning system with a reciprocating, rotary (rolling piston or rotary valve) or scroll compressor. 
     
     
         28 . The method as claimed in  claim 26  wherein the air conditioning system is a low temperature refrigeration system (with an evaporator temperature in the range of about −40 to about −12° C., particularly about −23° C. or preferably about −32° C.). 
     
     
         29 . 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 refrigerant according to  claim 1 . 
     
     
         30 . The heat transfer system of  claim 29  wherein the heat transfer system is a low temperature refrigeration system (with an evaporator temperature in the range of about −40 to about −12° C., particularly about −23° C. or preferably about −32° C.).