Experimental and numerical investigation of thermo-hydrodynamic performance of twin tube counter flow heat exchanger using cerium oxide nanofluid

Abstract

This study accomplished experimental and numerical investigations regarding cerium oxide (CeO2) nanofluid. The aim of this study is to estimate the thermo-hydrodynamic performance of twin tube counter flow heat exchangers (TTCFHEs) in the presence of CeO2 nanofluid. The CeO2 nanofluid concentrations varied from 0.1% to 0.3% by volume. In TTCFHEs, the mass flow rates of cold fluid flow varied from 3 LPM to 15 LPM (i.e. Reynolds number, Re varied from 2436 to 11,626). At the same time, hot fluid flows inside the shell at a constant mass flow rate of 6 LPM. For the numerical investigations, the standard k-ɛ model is adopted for the turbulent flow regimes, where the Reynolds number is varied from 2436 to 11,626. For validation purpose, the present numerical study and experimental data are matched with the correlations available in the literature. Further, numerical result of the Nusslet number is well agreed with the experimentally recorded data with a deviation less than 10%. From the study, it is witnessed that the outlet temperature of the cold fluid increases and decreases with increasing the concentrations of CeO2 nanofluids and with increasing the flow Reynolds number, respectively. On account of 0.3% and 0.2% CeO2 nanofluid, the average Nusselt number (Nu) showed almost 43.35% and 30.13% greater than that of base fluid with a moderate increase in the pressure drop in the range of mass flow rate is considered. However, from the numerical investigations, the performance evaluation criteria (PEC) increases with increasing nanofluid concentrations. At higher concentrations (i.e. 0.3%) of CeO2 nanofluid, the average PEC showed 16.65% higher than the 0.1% CeO2 nanofluid with a marginal increase in the pressure drop.