| abstract |
The invention provides a heat transfer composition comprising trans- 1,3,3,3-tetrafluoropropene (R-1234ze(E)), carbon dioxide. (R-744) and a third component selected from difluoromethane (R-32), 1, 1 -difluoroethane (R- 15.2a), fluoroethane (R-161), 1,1,1,2-tetrafluoroethane (R-134a), propylene, propane and mixtures thereof. The compositions are desgined to give higher flammable limit, higher ignition energy, and/or lower flame velocity. The compositions may be used to partially replace heat transfer agents with higher global warming potential such as refrigerants, heating agents, cooling agents, or foam blowing agents. |