A Novel High Ecciciency, Environmentally Frindly Refrigerant Mixture for Mobile Air-conditioners

초록

In this study, thermodynamic performance of a novel refrigerant mixture for automobile air conditioners was examined both theoretically and experimentally. The proposed mixtures are near-azeotropic ternary mixtures with a gliding temperature difference of about 1C and are composed of three environmentally friendly refrigerants. To measure their performance, a breadboard type air-conditioner was manufactured and both CFC12 and these mixtures at various compositions were tested under the same external conditions. During the tests, a conventional mineral oil for CFC12 was used and the expansion valve was adjusted to get the proper mass flow rate while the amount of charge varied to establish the same superheat and subcooling at the exits of the evaporator and condenser. Test results show that the ternary mixtures had 9-20% and 7-21% increases in COP and capacity respectively. Even though the mixtures contain one flammable component, they can be made nonflammable and also the fractionation is not a problem due to their near-azeotropic nature. Since their ODP and GWP are 0.0 and less than 50% that of HFC134a respectively, they are an excellent alternative refrigerants for both CFC12 and HFC134a in the long run.