Experimental Analysis on the Performance of MHTHS with Propylene Glycol and De Ionized Water Based Nanofluids

Abstract

The present study aimed to evaluate the heat transfer performance of three different mixtures of propylene glycol and De ionized water-based nanofluids in a mini hexagonal tube heat sink (MHTHS), as well as the influences of particle volume fraction and temperature on the thermo physical properties of nanofluids. The three different nanoparticles such as MgO, ZnO, and Al₂O₃ were dispersed in a mixture of Propylene Glycol (PG) and De ionized water (DIW) at four different volume fractions of 0.01, 0.02, 0.03, and 0.04 respectively. In colder regions, propylene Glycol was used as a better heat transfer fluid in miniature devices due to its anti-freezing properties. In this study, the experiment was conducted under two conditions First, the flow rate of DIW was maintained at 20L/h and the flow rate of three different nanofluids varied from 20 L/h to 50 L/h. Secondly, mixture proportions of 20%(PG)/80% (DIW) and 40% (PG)/60% (DIW) were taken as base fluids. The measurements of thermal conductivity and viscosity were also investigated. Experiments were performed to determine the heat transfer coefficient, Nusselt number, friction factor, and pressure drop of three different nanofluids flowing in an MHTHS were also investigated. Experimental results indicate that heat transfer coefficients and Nusselt number intensify with an increase in Volume fractions and Reynolds number. Consequently, friction factor and pressure drop were also investigated. The results revealed MgO-PG (20%)/DIW (80%) with 0.04VF results in a 36.6% enhancement in heat transfer rate compared to the base fluid. The Nusselt number for MgO-PG (20%)/DIW (80%) at 0.04VF showed an enhancement of 25.6% compared to the base fluid. ZnO-PG (40%)/DIW (60%) had a higher friction factor and pressure drop than the base fluid. Finally, the Reynolds number of nanofluids for selected velocity and contour escalated with increasing temperature and decreased with higher volume fraction. By optimizing the volume fraction of MgO-PG (20%)/DIW (80%) based nanofluids, the performance and longevity of miniature devices in colder regions can be effectively enhanced by providing an efficient cooling solution.