Ozone-friendly coolant mixt. - in which standard machine oils are readily soluble, comprises 1,1,1,2-tetra:fluoroethane coolant and hydrocarbon additive

摘要

Coolant mixt. for partially or fully hermetic refrigeration cycles is characterised by the addn. of 10-20 wt.% hydrocarbon (A) to the 1,1,1,2-tetrafluoroethane (R134a) coolant. USE/ADVANTAGE - Useful for CF or HFC based coolant mixts. The mixts. have a cooling performance comparable with CFC's, and standard refrigeration machine oils (e.g. mineral oils or polyalkylbenzene derivs.) are more readily soluble in the mixts. In an example, mixt. comprising R134a and 20 wt.% propane (partial pressures 12.0 and 10.4 respectively) gave an evapn. band of 0.02 (O) deg. C, a volumetric cooling performance of 563 (626) kj/m3 and an isentropic performance value of 1.93 (1.95)s at an evapn. temp. of -30 deg. C and a condensation temp. of 40 deg. C; (figs in brackets are for an R12 (CFC) coolant).