Performance assessment of an ejector enhanced dual temperature refrigeration cycle for domestic refrigerator application

Abstract

Recently, more than 10% energy saving potential was experimentally demonstrated in the condenser outlet split ejector expansion refrigeration cycle when compared with a conventional refrigerator. Nevertheless, introducing two-phase refrigerant into the evaporator causes excessive pressure drop, and compression of redundant vapor counteracts the ejector performance. To overcome these challenges, a modified cycle is proposed by adding a separator to minimize vapor feeding into the low-temperature evaporator. A cycle model is developed and verified by experimental data achieving 10% accuracy. Theoretical investigations of the new cycle indicate 7.7% and 5.5% efficiency and volumetric cooling capacity improvement comparing with the conventional condenser outlet split cycle at nominal conditions. Impacts of evaporating temperature, condensing temperature, pressure drop of the evaporator, heat recovery effectiveness, and separator efficiency are discussed. This study offers an option to further improve energy efficiency for the dual temperature domestic refrigerator.