Energy-Exergy Performance Comparison of Vapour Compression Refrigeration Systems using Three Nano Materials Mixed in R718 in the Secondry Fluid and Ecofriendly Refrigerants in the Primary Circuit and Direct Mixing of nano Materials in the Refrigerants

Abstract

This paper describes thermal modelling of vapour compression refrigeration system using (ii) eco-friendly refrigerants in primary circuit with nano particles mixed with R718 in secondary evaporator circuit. This model takes care of the secondary nanoparticles mixed in the fluids as input conditions as geometric characteristics of the system such as size of nanoparticles and the compressor speed to predict the secondary fluids output temperatures, the operating pressures, the compressor power consumption and the system overall energy performance. Such design analysis is conveniently useful to compare the thermal performance of different nanoparticles (Cu, Al2O3, TiO2) based nanofluid as a secondary fluid in a vapour compression refrigeration system. The influence of input variables on the irreversibilities in terms of exergy destruction ratio of the system is presented. Such a model can also be used to design various components viz. evaporator, compressor, condenser and throttle valve for vapour compression refrigeration systems for any desired cooling capacity. This model takes care of use of nanofluids as a secondary fluid in vapour compression refrigeration systems and simulate the non-linear equations of the system. It was observed that for the same geometric characteristics of the system, first and second law performance improved from 8% to 17% by using eco-friendly refrigerants in the primary circuit and nanoparticles mixed with water as a secondary fluid in VCS .and first and second law performance improved from 8% to 32% by mixing nano particles in the eco-friendly refrigerants in the primary circuit