Heat transfer compositions and methods
View Patent ↗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.
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, wherein the weight ratio of said HFC-32:HF-125 is from about 0.9:1.2 to about 1.2:0.9; (c) from greater than 0% to about 30% by weight of HFO-1234yf and from greater than 0% to about 30% by weight of HFO-1234ze, wherein the ratio of HFO-1234ze:HFO-1234yf is about 7:20 and wherein said HFO-1234ze consists essentially of transHFO-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 comprising from greater than 15% to about 30% by weight of HFC-32.
3. The heat transfer composition of claim 1 comprising from greater than 20% to about 30% by weight of HFC-32.
4. The heat transfer composition of claim 1 comprising from greater than 10% to about 30% by weight of HFC-125.
5. The heat transfer composition of claim 1 comprising from greater than 20% to about 30% by weight of HFC-125.
6. The heat transfer composition of claim 1 comprising from greater than 0% to about 25% by weight of HFO-1234yf.
7. The heat transfer composition of claim 1 comprising from greater than 0% to about 22% by weight of HFO-1234yf.
8. The heat transfer composition of claim 1 comprising from about 1% to about 30% by weight of HFO-1234ze.
9. The heat transfer composition of claim 1 comprising from about 5% to about 30% by weight of HFO-1234ze.
10. 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.
11. 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.
12. 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.
13. 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.
14. The heat transfer composition of claim 1 wherein HFO- 1234 ze is provided in an amount of about 7% and HFO-1234yf is provided in an amount of about 20%.
15. The heat transfer composition of claim 1 comprising from greater than 15% to about 35% by weight of HFC-134a.
16. The heat transfer composition of claim 1 comprising from greater than 15% to about 30% by weight of HFC-134a.
17. The heat transfer composition of claim 1 further comprising up to about 5% by weight of CF3I.
18. The heat transfer composition of claim 1 further comprising up to about 5% by weight of HFCO-1233ze.
19. 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, wherein the weight ratio of said HFC-32:HF-125 is from about 0.9:1.2 to about 1.2:0.9; (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 wherein the ratio of HFO-1234ze:HFO-1234yf about 7:20 and wherein said HFO-1234ze consists essentially of transHFO-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.
20. A heat transfer system comprising a compressor, a condenser and an evaporator in fluid communication, and a heat transfer composition according to claim 1 contained in said system, said condenser having an operating temperature of from about 35° C. to about 45° C.
21. The heat transfer system of claim 20 wherein said evaporator has an operating temperature of from about −40° C. up to less than about −15° C.
22. The heat transfer system of claim 20 wherein said evaporator has an operating temperature of from about −35° C. to about −25° C.