Thermal Performance Improvements of Vapour Compression Refrigeration System Using Eco Friendly Based Nanorefrigerants in Primary Circuit

Abstract

Now a days nano refrigerants are being considered as a most efficient heat transfer fluids having superior heat transfer properties than conventional refrigerants in various thermal applications. Refrigerant based nano fluid termed as “Nanorefrigerant” have the great potential for improve thing first law thermal performance in terms of coefficient of performance in the refrigeration and air conditioning system. The thermo physical properties by addition of different nanoparticle mixed with eco friendly refrigerant are analyzed and their effects on the coefficient of performance (C.O.P.) have been reported in this paper. The thermal modeling have been done for the same cooling load and same geometry parameter for all nanoparticles and refrigerant combination mixture in the vapour compression refrigeration based chiller system having two concentric tube type heat exchanger as evaporator and condenser. The experimental results are indicating the thermal conductivity, dynamic viscosity and density of nanorefrigerant (different nanoparticle i.e. Cu, Al2O3,CuO and TiO2 with eco friendly refrigerant R134a,R407c and R404A) increased about 15 to 94 %, 20% and 12 to 34 % respectively compared to base refrigerant on the other hand specific heat of nanorefrigerant is slightly lower that the base refrigerant. Moreover Al2O3/R134a nanorefrigerant shows highest C.O.P. of 35%. R404A and R407 with different nanoparticle show enhancement in C.O.P. about 3 to 14 % and 3 to 12 % respectively. Therefore application of nanorefrigerant in refrigeration and air conditioning system is most required to improve the performance of the system.