Research on the flammable characteristics of fluoroethane (R161) and its binary blends.

As one of the potential new generation refrigerants, R161 possesses the suitable thermodynamic properties and small climate change effects, but it is flammable. This paper contributed to its fundamental flammable characteristics theoretically and experimentally. Firstly, its flames were researched under various testing conditions. Then influences of temperature and vessel dimensions on the flammability limits of R161 were tested and analyzed. The results indicated that the lower flammability limits of R161 increased with the decrease of temperature while its upper flammability limits reduced oppositely, when initial temperature varied from 55°C to -5°C. Thirdly, a method was proposed to estimate the refrigerants' flammability limits, which concerned three impact parameters, the gas concentration, bond dissociation energies and enthalpy variations. Finally, the flame suppression effects of 1,1,1,2,3,3,3-heptafluoropropane (R227ea), trifluoroiodomethane (R13I1), and trans-1,3,3,3-tetrafluoropropene (R1234ze) to R161 were tested, and the critical flammability ratios (CFR) of some inhibitors to R161 were obtained