THERMODYNAMIC ANALYSES OF THE CFC-12 AND HFC-134A REFRIGERATION CYCLES

Dichlorodifluoromethane (CFC-12) is the major contributor to ozone dep letion. The new refrigerant tetrafluorethane (HFC-134a), which is a le ading candidate to replace CFC-12 in refrigeration and air-conditionin g applications, has been investigated from the standpoint of thermodyn amic performance. For this purpose, a computer program is written to c alculate the thermodynamic properties of HFC-134a, which can be used a s a reference for analyses. A comparison has also been made for CFC-12 and HFC-134a refrigerants, which indicates that CFC-12 may be replace d by HFC-134a without a significant loss in overall thermal performanc e. It is found that the volumetric refrigerating effect of HFC-134a is less than that of CFC-12 for the same operating conditions. Thus, a l arger compressor will be required for the same refrigeration capacity with HFC-134a.