Abstract |
The synthesis of new non-chlorinated refrigerants expands the base of alternatives for replacing ozone-depleting chlorofluorocarbons (CFCs) and their first-generation replacements, hydrochlorofluorocarbons (HCFCs). Besides the direct use of these refrigerants, there is also the potential to combine them with other compounds to form blends. In the work, the potential for azeotrope formation and performance was evaluated for fluorinated ethers, ethanes, and propanes. Azeotrope formation was predicted using an interaction parameter for the mixture which was based on the dipole moments and volumes of the components. Dipole moments for the new compounds were predicted from the molecular structure. Of 20 fluorinated ether and hydrocarbon pairs tested, seven were found to form azeotropes. Results from the work predicted azeotropes with boiling points between -46 C (-52 F) and -19 C (-2 F), indicating potential replacements for CFC-12 and R-502, an azeotrope of HCFC-22 and CFC-115. Azeotrope performance in vapor-compression cycles was then evaluated. |