Ozone layer friendly fluorohydrocarbon refrigerant fluid composition, useful in heat transfer systems, comprising difluoromethane, pentafluoroethane, 1,1,1,2-tetrachloroethane and R-143a

摘要

A novel fluorohydrocarbon composition (I) contains (by weight) 1-50 (preferably 15-35)% R-32 (difluoromethane), 10-90 (preferably 10-50)% R-125 (pentafluoroethane), 1-50 (preferably 30-50)% R-134a (1,1,1,2-tetrafluoroethane) and 5-20% R-143a. An independent claim is included for a method for converting a heat transfer system adapted to R-22 (monochlorodifluoromethane), involving use of (I) after rinsing with a solution (II) comprising (A) one or more non-flammable fluorohydrocarbon propellant(s) and (B) one or more of propane, butane, isobutane, propylene, trans-1,2-dichloroethylene, ethyl chloride, dimethyl ether (methoxymethane) and/or carbon dioxide.