Abstract:
An attempt has been made to improve the heat transfer characteristics of the vapor compression refrigeration cycle
using nanorefrigerant (R134a and Al2O3, size 20 nm). The performance parameters such as, coefficient of performance,
cooling capacity, energy consumption, and temperature drop across condenser and evaporator have been investigated
and analyzed. This has been done by varying the mass fraction of nanoparticles of Al2O3 (0.5–1 wt%) and the flow rate of
nanorefrigerant. The investigation has been carried out using three types of nanorefrigerants, i.e. pure R134a,
R134aþAl2O3 (0.5 wt%), and R134aþAl2O3 (1 wt%) at flow rates of 6.5 L/h and 11 L/h, respectively. The coefficient
of performance of the refrigeration system using 0.5% of Al2O3 (wt%) is found to be improving with volume flow rates of
nanorefrigerant, i.e. 7.20% for 6.5 L/h and 16.34% for 11 L/h. The use of nanorefrigerant (R134aþAl2O3) has also resulted
in a significant increase in the cooling capacity of the refrigeration system. A substantial drop in the temperature across
the condenser (3.0–23.77%), and gain in temperature across the evaporator (4.69–39.30%) is also observed for the
refrigeration system under investigation
