Heat transfer compositions, methods, and systems
The present invention relates to a refrigerant composition, including difluoromethane (HFC-32), pentafluoroethane (HFC-125), and trifluoroiodomethane (CF 3 I) for use in a heat exchange system, including air conditioning and refrigeration applications and in particular aspects to the use of such compositions as a replacement of the refrigerant R-410A for heating and cooling applications and to retrofitting heat exchange systems, including systems designed for use with R-410A.
1 . A refrigerant consisting of the following three compounds, with each compound being present in the following relative percentages:
39% to 45% by weight difluoromethane (HFC-32),
1% to 4% by weight pentafluoroethane (HFC-125), and
51% to 57% by weight trifluoroiodomethane (CF3I), wherein the refrigerant is non-flammable.
2 . The refrigerant of claim 1 consisting of:
about 41% to about 43% by weight difluoromethane (HFC-32),
1% to 4% by weight pentafluoroethane (HFC-125), and
about 53% to about 56% by weight trifluoroiodomethane (CF3I).
3 . The refrigerant of claim 2 comprising:
41%+/−0.5% by weight difluoromethane (HFC-32),
3.5%+/−0.5% by weight pentafluoroethane (HFC-125), and
55.5%+/−0.5% by weight trifluoroiodomethane (CF3I).
4 . The refrigerant of claim 2 consisting of:
41%±1% by weight difluoromethane (HFC-32),
3.5%±0.5% by weight pentafluoroethane (HFC-125), and
55.5%±0.5% by weight trifluoroiodomethane (CF3I).
5 . The refrigerant of claim 2 consisting of the following three compounds, with each compound being present in the following relative percentages:
41% by weight difluoromethane (HFC-32),
3.5% by weight pentafluoroethane (HFC-125), and
55.5% by weight trifluoroiodomethane (CF3I).
6 . A method of cooling in a heat transfer system comprising an evaporator, a condenser and a compressor, the process comprising the steps of:
i) condensing a refrigerant consisting of the following three compounds, with each compound being present in the following relative percentages:
39% to 45% by weight difluoromethane (HFC-32),
1% to 4% by weight pentafluoroethane (HFC-125), and
51% to 57% by weight trifluoroiodomethane (CF 3 I) and
ii) evaporating said refrigerant in the vicinity of the body or article to be cooled; wherein the temperature of the refrigerant in the evaporator is in the range of from about −40° C. to about 10° C.
7 . The method of claim 6 wherein the temperature of the refrigerant in the evaporator is in the range of from about −30° C. to about 5° C.
8 . The method of claim 6 wherein the temperature of the refrigerant in the evaporator is in the range of from about −40° C. to about −10° C.
9 . The method of claim 6 wherein the system is a residential air conditioning system and wherein the temperature of the refrigerant in the evaporator is in the range of from about 0° C. to about 10° C.
10 . The method of claim 6 wherein the system is a chiller system and wherein the temperature of the refrigerant in the evaporator is in the range of from about 0° C. to about 10° C.
11 . The method of claim 6 wherein the system is a low temperature refrigeration system and wherein the temperature of the refrigerant in the evaporator is in the range of from about −40° C. to about −12° C.
12 . A method of retrofitting an existing heat transfer system that contains R-410A refrigerant comprising:
(a) removing at least a portion of said R-410A refrigerant from the system; and
(b) introducing into the heat transfer system a refrigerant consisting of the following three compounds, with each compound being present in the following relative percentages:
a. 39% to 45% by weight difluoromethane (HFC-32),
b. 1% to 4% by weight pentafluoroethane (HFC-125), and
c. 51% to 57% by weight trifluoroiodomethane (CF3I).
13 . The method of claim 12 wherein said removing step comprises removing at least about 50% of the R410 refrigerant from the system.
14 . The method of claim 12 wherein said system is a chiller system.
15 . The method of claim 12 wherein said system is a residential air conditioning system.
16 . The method of claim 12 wherein said method does not include any substantial modification of the system to accommodate said refrigerant introduced in step (b).
17 . The method of claim 16 wherein said method does not include modification of the condenser, the evaporator or the expansion valve to accommodate said refrigerant introduced in step (b).