Experimental Study of the Effect of Distilled Water, R O Water, Lubricating Oil, Ethanol and Tio2nanofluid Concentrations on Pool Boiling Heat Transfer: Investigating the Effects of Nanofluid Concentrations on Pool Boiling Heat Transfer

Abstract

This paper focuses on two methods using nanofluids to deposit nanoparticles for the creation of enhanced surfaces for boiling heat transfer and changing the base fluid along with adding some quantities of nanoparticles to base fluids. Recent research has confirmed a buildup of a thin layer of nanoparticles on the heated surface during nucleate boiling in nanofluids. Most of these studies report no change of heat transfer and even worse, the presence of heat transfer deterioration. However, a few others report a heat transfer enhancement. In order to understand these controversial results, experiments were conducted to explore the mechanism of surface coating during nucleate boiling in nanofluids, changing the base fluidswith different Tio2nanofluids concentrations and to study the pool boiling curve. The recent report showed that the thickness of the nanoparticle layer was observed to depend on the nanoparticles concentration and the experiment duration. Compared to a clean surface, the wettability of the surfaces with a TiO2 nanoparticle layer has been significantly improved. However, up to 50% of heat transfer coefficient deterioration was observed with TiO2nanofluids fluid concentration in water pool boiling. When tested in pure water, the addition of nanoparticle-concentration to base liquid showed significant increase in critical heat flux compared with the critical heat flux in pure water.