Investigation of energy and exergy performance on a small-scale refrigeration system with PCMs inserted between coil and wall of the evaporator cabin

Abstract

Domestic refrigerators have become an indispensable part of the modern life. Since they are connected to the electric mains and operate throughout the day and year, they consume a lot of energy. Several experimental studies show that the addition of phase change material in the refrigerators at various locations improves the energy efficiency of the refrigerators. In this work, an experimental study was conducted to explore and reveal the improvement in energy efficiency of a small-scale refrigeration system when PCM was applied between the evaporator coil and the insulation. It was observed that the addition of PCM for a thickness of 0.03 m could reduce the heat ingress inside the evaporator by 15–19%. Moreover, the compressor ON cycle time and the temperature fluctuation inside the freezer cabinet were also relatively lesser. The per day energy consumption was reduced by 15.7–17.3% and the improvement in COP was found to be 17.4% with the addition of PCM. The refrigeration system was able to retain its desired temperature level for a period of 5 h even after the power supply was switched OFF. This idea of incorporating PCM between coil and insulation could be extended to household refrigerators so as to reduce the energy consumption. This would come handy in case of power outages which are very common in places having low grid reliability.