Investigation on thermophysical properties and heat transfer performance of heat pipe charged with binary mixture based ZnO-MgO hybrid nanofluids

Hybrid nanofluids are attracted by the researchers due to their remarkable thermal conductivity as well as heat transfer behavior. Zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles were synthesized by co-precipitation and sol-gel method. The nanoparticles were characterized through X-ray diffraction studies, Fourier Transform Infra-Red spectroscopy analysis and scanning electron microscopy and energy dispersive X-ray spectroscopy methods. The produced nanoparticles were converted into nanofluids by adding a base solution as a blend of ethylene glycol and water (60:40%) and surfactant as cetyl trimethyl ammonium bromide (CTAB) using ultra-sonication process in the two-step method. Hybrid nanofluids of different concentrations (0%, 0.0125%, 0.025%, 0.05%, 0.075% and 0.1%) have been prepared and the effect of thermal conductivity, density and viscosity were determined at various temperatures(30-80 degrees C).The performance of heat pipe was analyzed with hybrid ZnO-MgO nanofluids by convective heat transfer method for three heat power inputs (30-90 W). ZnO-MgO hybrid nanofluid exhibit enhanced thermophysical properties as compared to base fluid alone. Decrease in thermal resistance and improvement in the heat transfer coefficient of nanofluids was observed by 4.07% and 28.9% respectively. The enriched thermphysical and heat transfer properties of this hybrid nanofluid could be used for heat transfer applications in heat exchanging devices. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

Hybrid nanofluids with enhanced thermophysical properties were prepared by synthesizing zinc oxide and magnesium oxide nanoparticles, converting them into nanofluids, and analyzing their heat transfer characteristics. The hybrid nanofluids showed improved thermal conductivity and heat transfer coefficient, making them suitable for heat transfer applications in heat exchanging devices.