Evaluation of a Refrigeration System Based on Nano-Refrigerants and Nano-Lubricants

Abstract

Most of studies reported that disperse nanoparticles into refrigerants and lubricating oils lead to improve a coefficient of performance, due to improvement of thermal physics properties of a pure fluid, which leads to reduced energy consumption. Using nanoparticles in a refrigeration system is associated with many difficulties such as the cost of preparing and obtaining a stable and homogeneous mixture for a longer time with less agglomeration and sedimentation. In this research, nanoparticles were prepared as a mixture in an inexpensive and easy way consisting of copper and cerium oxides for the first time, with suitable average diameter to verify the possibility of overcoming the problem of stability of nanoparticles for a longer time with refrigerant. As most studies focus on improving the thermal properties of a refrigerant by using high thermal conductivity nanoparticles, while this study focuses on improving both of thermal conductivity of refrigerant and stability of nanoparticles with a refrigerant. Some studies have reported on the use of copper oxide and its effect on improving the performance of refrigeration system, but cerium oxide has not been used in refrigeration systems and this research will open the door to cerium oxide as a single material and as a mixture with copper oxide to verify the possibility of this oxide to create greater stability of nanoparticles and improve thermal properties.