Heat transfer studies in a plate heat exchanger using Fe2O3-water-engine oil nanofluid

Abstract

Improving heat transfer performance of conventional fluid creates significant energy savings in process Industries. In this aspect, experimental study was performed to evaluate the heat transfer performance of Fe2O3-Water (W)-Engine Oil (EO) nanofluid at different concentrations and different hot fluid inlet temperatures in a plate heat exchanger. Experiments were conducted by mixing Fe2O3 nanoparticle (45 nm) in a base fluid of water-engine oil mixture with volume fractions of 5%EO + 95%W and 10%EO +90%W. Main aim of the present study is to assess the impact of variations in nanoparticle volume fraction and hot fluid inlet temperature on the heat transfer performance of prepared nanofluid. Based on the experimental results, convective heat transfer coefficient, Reynolds, Prandtl and Nusselt number were determined. Result shows that at the hot fluid inlet temperature of 75?C, the increase in Nusselt number and convective heat transfer co efficient are optimum at 0.9 vol. % nanoparticle for both the base fluid mixtures. The increase in heat transfer coefficient is because of the Brownian motion (increasing thermal conductivity) effect, motion caused by temperature gradient (Thermo-phoretic) and motion due to concentration gradient (Osmophoretic). If the volume fraction of nanoparticle increases then Reynolds number increment is higher than Prandtl number decrement, which augments Nusselt number as well as convective heat transfer coefficient.