Methods for Improving Thermodynamic Energy and Exergy Performance of Vapor Compression Refrigeration Systems Using Thirteen Eco-Friendly Refrigerants in Primary Circuit and Tio2 Nano Particles Mixed with R718 Used In Secondary Evaporator Circuit for Reduc

Abstract

The methods for improving energy and exergetic efficiency have been considered in this paper by using water as secondary coolant in evaporator with nano particles of Al2O3 and TiO2 mixed R718 refrigerant is investigated in this paper. Detailed energy and exergy analysis of multi-evaporators at different temperatures in the vapor compression refrigeration systems have been done in terms of performance parameter for R507a, R125, R134a, R290, R600, R600a, R410a, R407c, R404a and R152a refrigerants. The numerical computations have been carried out for both systems. The use of nano particles improves the energy and exergy performance significantly. The best thermodynamic performance is found using R152a and worst performance is observed using R410a. Due to flammable nature of R290, R600, R600a and R152a , the R134a is recommended for domestic applications. The results were compared by using water in secondary circuit with nano refrigerants and without nano-particles used and it was found that use of nano-particles improves thermal performances significantly. The energy performance improvement in terms of COP and exergetic performance in terms of exergetic efficiency (rational efficiency) using TiO2 is better than using Al2O3 with R718 refrigerant in the secondary evaporator circuit.