Experimental study of heat transfer characteristics of nanofluid nucleate and film boiling on horizontal flat plate

Abstract

This study investigated the heat transfer characteristics of nano fluid nucleate and film boiling experimentally. To this end, Al2O3 and SiO2 deionized water-based nano fluids were prepared with three volumetric concentrations of 0.1%, 0.3%, and 0.5%. Boiling experiments were conducted on a circular and polished copper surface with a diameter of 25 mm. The results illustrated that the addition of nanoparticles to the base fluid reduced the heat transfer coefficient of nucleate boiling. Boiling of nano fluids elevated surface wettability and the critical heat flux was significantly higher than that of pure deionized water. The Al2O3 deionized water-based nano fluid with a volumetric concentration of 0.5% had the best performance, with a critical heat flux of 44.56% higher than that of pure deionized water. The presence of nanoparticles in the deionized waterbased nano uid improved the heat transfer coefficient of film boiling. As demonstrated by the results, the stable film boiling for nano fluids began with a more significant difference in wall superheat temperature than pure deionized water. Among the investigated concentrations, the volumetric concentration of 0.5% yielded the best performance for both nano fluids such that the minimum heat fluxes of Al2O3 and SiO2 deionized water-based nano fluids increased by 35.01% and 34.40%, respectively, compared to pure deionized water.