Experimental investigation on performance enhancement of vapor compression refrigeration (VCR) systems using nanorefrigerant [R-134a + ZrO2] at steady-state

This paper is mainly concerned with an experimental investigation of the performance enhancement of a vapor compression refrigeration (VCR) system using nano refrigerant (R-134a + ZrO 2 ) at steady-state conditions. The refrigeration system has become a major consumer of energy for many industrial applications. Therefore, there is a need to enhance the refrigeration systems. The performance of a refrigeration system can be improved by either reducing the compressor power or increasing the heat-absorption rate in the evaporator. The use of nano refrigerant can lead to lower power consumption, increased heat transfer capacity, and reduced (pumping, power, and particle clogging). A two-step method was prepared by dispersing ZrO 2 (0.5, 1, and 1.5 % v) in PAG oil. A magnetic stirrer and an ultrasonic homogenizer were used. ZrO 2 nanoparticles were selected owing to their superior thermophysical properties. Through the experiments, the discharge pressure (Pdis) varies from 11.37 bar to 7.618 bar, and the suction pressure (Psuc) changes from 1.06 to o.85 bar, which gives a VCR system pressure ratio (PR) between 6.45 and 8.32. The use of nano refrigerant reduced the compressor energy consumption by 7.68 %. Finally, the result revealed the use of (R-134a/ZrO 2 ) nano refrigerant has also resulted in a significant increase in the cooling capacity and thermal efficiency of the system.