Heat Transfer Performance of Green Bioglycol-Based TiO2–SiO2 Nanofluids

Abstract

The dispersion of nanoparticles in conventional heat transfer fluids has been proven to improve the performance of the fluids. However, study on the heat transfer performance of hybrid nanofluids in the mixture of water and green Bio-glycol are limited in the literature. This paper presents the heat transfer performance and friction factor of green Bio-glycol based TiO2-SiO2 nanofluids. The TiO2 and SiO2 nanoparticles were dispersed in the mixture of 60:40 water: Bio-glycol (W/BG) and prepared at various concentrations up to 2.5% and composition ratios of 20:80. The experimental study on forced convection heat transfer was done under turbulent flow at constant heat flux for different operating temperatures of 30, 50 and 70 °C. The maximum heat transfer enhancements of the TiO2-SiO2 nanofluids at different bulk temperatures of 30, 50 and 70 °C were observed to be up to 128.1%, 73.95%, and 67.81%, respectively for 2.5% volume concentration. A slight friction factor escalation of the nanofluids was observed with 12% maximum increment. New correlations were developed to estimate the Nusselt number, and friction factor. The equations showed good accuracy with average deviations of less than 4.3%. As a conclusion, the employment of the eco-friendly coolant nanofluids in improving thermal performance is proven and applicable for turbulent forced convection heat transfer applications. Hence, the utilization of the green Bio-glycol based TiO2-SiO2 nanofluids at 2.5% volume concentration was recommended for various engineering applications.