Comparative Performance of Domestic Refrigerator by Using Constant and Variable Speed Compressors with HC and HFC Refrigerants.

Document Type : Research Studies

Authors

1 a demonstrator at mechanical power and energy department Minya university

2 a lecturer at the Department of mechanical power and energy, Minia University

3 an Associate Professor at the Department of mechanical power and energy, Minia University

4 an Emeritus professor at the Department of mechanical power and energy, Minia University

Abstract

Vapor compression cooling systems consume high electrical energy and contribute to environmental impacts due to the used of traditional harmful working fluids. Use of a capacity control method can reduce energy consumption and improve service life of these systems. Variable speed compressor is considered as the best and most efficient method of capacity control. Hydrocarbons can be considered as the most proper alternatives to traditional refrigerants in terms of energy efficacy and environmental impacts. In the actual work a comparison between the performance and daily energy consumption of a household refrigerator (382 liters) with constant and a variable speed compressor subject to identical operation conditions are carried out. In addition, the overall performance of the both systems using HC-600a and HFC-134a refrigerants was carried out and compared.
Results showed that the optimum charges for HC600a and HFC-134a were 55 g and 110 g respectively. The pull-down time for HC-600a is lower than that of HFC-134a system by 24.3%. The variable speed compressor system with HC-600a saves about 39.7% energy consumption in comparison to constant speed compressor system with the same refrigerant with COP enhancement by 9.6 %. Using variable speed compressor with HC600a can save energy by about 40.5% and improve the COP by 10.8% comparing to constant speed compressor system with HFC-134a. In general, variable-speed capacity control compressor offers more energy savings with better performance compared to constant speed compressor. The overall system performance and the daily energy consumption has proved that HC-600a could be the best long-term alternative to phase out of HFC-134a.

Keywords

Main Subjects