Abstract
In this investigation, a domestic refrigerator was designed to work with R-134a and the possibility of using mixed refrigerants. The effect of condenser temperature and evaporator temperature on COP, refrigerating effect was investigated. The energy consumption of the refrigerator during experiment with mixed refrigerant and R-134a was measured. The results shows the continuous running and cycling results showed that R134a with a charge of 100 g or mixed refrigerant with charge of 80 mg or more satisfy the required freezer air temperature of −12 °C. The lowest electric energy consumption was achieved using mixed refrigerant with temperature level is less than -15oC. This combination achieved higher volumetric cooling capacity and lower freezer air temperature compared to R-134a. Experimental results of the refrigerator using mixed refrigerant were compared with those using R134a. Pull-down time, pressure ratio and power consumption of mixed refrigerant refrigerator were lower than those of R134a refrigerator by about 7.6%, 5.5% and 4.3%, respectively. Also, actual COP of mixed refrigerant refrigerator was higher than that of R-134a by about 7.6%. Lower on-time ratio and energy consumption of mixed refrigerant refrigerator is nearly 14.3% and 10.8%, respectively, compared to those of R-134a refrigerator were achieved. The COP and other result obtained in this experiment show a positive indication of using mixed refrigerant as refrigerants in domestic refrigerator.