Experimental investigation on Thermo-hydraulic performance of radiator with preheating effects on engine performance from the waste heat using THNF coolant

Abstract

The present paper deals with the thermal and hydraulic performance of engine radiator with Al2O3, CuO, and TiO2 nanoparticles distributed at an equal volume fraction of (0.06–0.12%) called THNF (Ternary Hybrid Nanofluid), into the base fluid water, operated under 3–8lpm CFR (Coolant Flow Rate), and fan velocity varied 0.25–1.25 m s–1 at 50% load on the engine. Preparation, detailed thermophysical properties evaluation, and characterization (Scanning Electron Microscopy, Zeta potential), justifying nanofluid durability for the long run. Radiator performance parameter, PEC (Performance Evaluation Criteria), and friction factors are investigated to evaluate the penalty in pressure drop for the heat transfer enhancement. Also, the effects of fuel preheating on engine parameters (BTE and BSFC) using 0.12% THNF coolant on the engine performance at part loads with variable radiator parameters are investigated. The experimental analysis revealed a maximum heat transfer enhancement of 17.6% at a 6lpm coolant flow rate operated under a 0.12% volume fraction of THNF and requiring a 20.6% higher friction factor than water. The PEC value is obtained within the limit of 1.0045–1.098, which indicates a remarkable heat transfer enhancement on nanoparticle addition. Concurrently fuel elevated temperature resulted in in 13.06% higher brake thermal efficiency, 16.6% lower BSFC, and corresponding 13.54% fuel consumption saving obtained at 0.25 m s–1 of frontal air velocity, 6lpm of 0.12% THNF coolant flow rate at 50% load condition on engine and radiator. Therefore, preheating fuel through the radiator waste heat successfully improves the thermal efficiency, lowers the BSFC, and saves fuel consumption. © 2022, Akadémiai Kiadó, Budapest, Hungary.