transcritical, refrigeration, r744, household refrigerator, compressor
The vapor compression cycle using refrigerant CFC (chlorofluorocarbon) and HCFC (hydrochlorofluorocarbon) is widely used in refrigeration, air-conditioning and water heating industries. Utilization of these gases are prohibited by the Montreal Protocol. The critical temperature of carbon dioxide (CO2) is much lower than that of the other refrigerants, namely 31.06°C. The gas cooling process occurs at a constant pressure but at variable temperatures takes the place of the condensation process that occurs at both constant pressure and temperature. Domestic type refrigerators use smaller compressor capacities between 100 W to 300 W. Data on CO2 (R744) refrigeration cooling cycle applications and calorimetric measurements are not available in the market and literature. Utilizing the experimental setup, our research group has developed a model for mass flow rate and compressor power of commercially available R744 compressors at different pressures and temperatures. In this article, experimental results and mathematical model calculations will be presented and discussed.