摘要 |
The invention provides a heat transfer composition comprising (i) a first component selected from frans-1,3,3,3-tetrafluoropropene (R-1234ze(E)), cis-1,3,3,3- tetrafluoropropene (R-1234ze(Z)) and mixtures thereof; (ii) carbon dioxide (R-744); and (iii) a third component selected from 2,3,3,3-tetrafluoropropene (R-1234yf), 3,3,3- trifluoropropene (R-1243zf), and mixtures thereof. |