Heat transfer compositions and methods

Abstract

Compositions, methods and systems which comprise or utilize a multi-component mixture comprising: (a) HFC-32; (b) HFC-125; (c) HFO-1234yf and/or HFO-1234ze; (d) HFC-134a. In certain non-limiting aspects, such refrigerants may be used as a replacement for R-404A.

What is claimed is: 
     
         1 . A heat transfer composition comprising: (a) from about 10% to about 35% by weight of HFC-32; (b) from about 10% to about 35% by weight of HFC-125; (c) from about 0% to about 30% by weight of HFO-1234yf and from greater than 0% to about 30% by weight of HFO-1234ze; (d) from about 10% to about 35% by weight of HFC-134a, with the weight percent being based on the total of the components (a)-(d) in the composition. 
     
     
         2 . The heat transfer composition of  claim 1  wherein said HFO-1234ze comprises trans-HFO-1234ze. 
     
     
         3 . The heat transfer composition of  claim 1  comprising from greater than 15% to about 30% by weight of HFC-32. 
     
     
         4 . The heat transfer composition of  claim 1  comprising from greater than 20% to about 30% by weight of HFC-32. 
     
     
         5 . The heat transfer composition of  claim 1  comprising from greater than 10% to about 30% by weight of HFC-125. 
     
     
         6 . The heat transfer composition of  claim 1  comprising from greater than 20% to about 30% by weight of HFC-125. 
     
     
         7 . The heat transfer composition of  claim 1  having a weight ratio of HFC-32:HFC-125 of from about 0.9:1.2 to about 1.2:0.9. 
     
     
         8 . The heat transfer composition of  claim 1  comprising from greater than 0% to about 25% by weight of HFO-1234yf. 
     
     
         9 . The heat transfer composition of  claim 1  comprising from greater than 0% to about 22% by weight of HFO-1234yf. 
     
     
         10 . The heat transfer composition of  claim 1  comprising from about 1% to about 30% by weight of HFO-1234ze. 
     
     
         11 . The heat transfer composition of  claim 1  comprising from about 5% to about 30% by weight of HFO-1234ze. 
     
     
         12 . The heat transfer composition of  claim 1  comprising from greater than 0% to about 25% by weight of HFO-1234yf and from about 1% to about 30% by weight of HFO-1234ze. 
     
     
         13 . The heat transfer composition of  claim 1  comprising from greater than 0% to about 22% by weight of HFO-1234yf and from about 5% to about 30% by weight of HFO-1234ze. 
     
     
         14 . The heat transfer composition of  claim 1  having a weight ratio of HFO-1234ze:HFO-1234yf of about 5:1 to about 0.1:1. 
     
     
         15 . The heat transfer composition of  claim 1  having a weight ratio of HFO-1234ze:HFO-1234yf of between about 3:1 to about 0.2:1. 
     
     
         16 . The heat transfer composition of  claim 1  having a weight ratio of 134a to a combination of HFO-1234ze and HFO-1234yf between about 5:7 to about 1:1. 
     
     
         17 . The heat transfer composition of  claim 1  having a weight ratio of 134a to a combination of HFO-1234ze and HFO-1234yf of about 4:6. 
     
     
         18 . The heat transfer composition of  claim 1  wherein HFO-1234ze is provided in an amount of about 20% and HFO-1234yf is provided in an amount of about 9%. 
     
     
         19 . The heat transfer composition of  claim 1  wherein HFO-1234ze is provided in an amount of about 7% and HFO-1234yf is provided in an amount of about 20%. 
     
     
         20 . The heat transfer composition of  claim 1  wherein HFO-1234ze is provided in an amount of about 26%. 
     
     
         21 . The heat transfer composition of  claim 1  wherein HFO-1234ze is provided in an amount of about 17% and HFO-1234yf is provided in an amount of about 9%. 
     
     
         22 . The heat transfer composition of  claim 1  comprising from greater than 15% to about 35% by weight of HFC-134a. 
     
     
         23 . The heat transfer composition of  claim 1  comprising from greater than 15% to about 30% by weight of HFC-134a. 
     
     
         24 . The heat transfer composition of  claim 1  further comprising up to about 5% by weight of CF3I. 
     
     
         25 . The heat transfer composition of  claim 1  further comprising up to about 5% by weight of HFCO-1233ze. 
     
     
         26 . A method of replacing an existing heat transfer fluid contained in heat transfer system comprising removing at least a portion of said existing heat transfer fluid from said system, said existing heat transfer fluid being HFC-404A and replacing at least a portion of said existing heat transfer fluid by introducing into said system a heat transfer composition comprising: (a) from about 10% to about 35% by weight of HFC-32; (b) from about 10% to about 35% by weight of HFC-125; (c) from about 0% to about 30% by weight of HFO-1234yf and from greater than 0% to about 30% by weight of HFO-1234ze; (d) from about 10% to about 35% by weight of HFC-134a, with the weight percent being based on the total of the components (a)-(d) in the composition. 
     
     
         27 . A heat transfer system comprising a compressor, a condenser and an evaporator in fluid communication, and a heat transfer composition in said system, said heat transfer composition comprising: (a) from about 10% to about 35% by weight of HFC-32; (b) from about 10% to about 35% by weight of HFC-125; (c) from about 0% to about 30% by weight of HFO-1234yf and from greater than 0% to about 30% by weight of HFO-1234ze; (d) from about 10% to about 35% by weight of HFC-134a, with the weight percent being based on the total of the components (a)-(d) in the composition, said condenser having an operating temperature of from about 35° C. to about 45° C. 
     
     
         28 . The heat transfer system of  claim 27  wherein said evaporator has an operating temperature of from about −40° C. up to less than about −15° C. 
     
     
         29 . The heat transfer system of  claim 27  wherein said evaporator has an operating temperature of from about −35° C. to about −25° C.