Energy And Exergy Performance Evaluation Of A Vapour Compression Refrigeration System Using Conventional (r134a) And Tio₂ Nano-refrigerant

Abstract

The Increasing Demand For Energy-efficient And Environmentally Sustainable Refrigeration Systems Has Led To The Exploration Of Advanced Working Fluids. This Study Presents The Energy And Exergy Analysis Of A Vapour Compression Refrigeration System (VCRS) Operating With A Conventional Refrigerant (R134a) And A Nano-refrigerant Formed By Dispersing 0.1% Titanium Dioxide (TiO₂) Nanoparticles Into The Compressor Lubricant. Energy Analysis, Based On The First Law Of Thermodynamics, Was Used To Determine The Refrigeration Effect, Compressor Work And Coefficient Of Performance (COP), While Exergy Analysis, Based On The Second Law, Was Used To Quantify Irreversibilities And Exergy Destruction In The Compressor, Condenser, Expansion Valve And Evaporator. Experiments Were Carried Out On A Vapour-compression Test Rig At Constant Water Temperatures Of 16°C, 18°C And 20°C. The Results Show That The Addition Of TiO₂ Nanoparticles Increases The Refrigeration Effect By 1.24–2.86% And Reduces Compressor Work By 5.78–8.71% Relative To Conventional R134a, Yielding An Improvement In Theoretical COP Of 9.14–10.45%, With The Maximum Improvement Of 10.45% Obtained At 18°C. Exergy Destruction Was Reduced In Every Major Component, With The Largest Reductions Observed In The Compressor (6.60–12.24%) And The Expansion Valve (7.14–15.79%), And Smaller Reductions In The Condenser (4.17–5.47%) And Evaporator (6.40–7.41%). The Study Concludes That A 0.1% TiO₂ Nano-refrigerant Is A Favourable And Thermodynamically Superior Alternative To Conventional R134a For Vapour Compression Refrigeration Systems.

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