Experimental Studies on Pool Boiling of Water-Based Al2O3, CuO and Hybrid Nanofluids

Experiments on pool boiling of distilled water and nanofluids: Al2O3-water, CuO-water and Hybrid (Al2O3-water and CuO-water, mixed in equal volume) have been performed on a heated nichrome wire that is submerged in distilled water and the nanofluids. This study aims to find increase in the critical heat flux (CHF) due to hybrid nanofluids mixed in equal volumes of Al2O3-water and CuO-water nanoparticles. The volume concentrations of nanoparticles were varied from 0.01 to 0.05%. The heat flux to the test heater was impressed and the corresponding current and voltage supply were recorded using a data logger until the wire started becoming red hot and then broke which is referred to as the critical heat flux. Experiments show that there is an enhancement of critical heat flux (CHF) on varying the vol. %age concentration. It is found that the CHF is quite high in case of the hybrid nanofluids as compared to the base fluid that is distilled water and single particle nanofluids. Enhancement of CHF to around 91.06% in the hybrid nanofluids has been estimated when compared with the distilled water. The heat flux versus excess temperature has been plotted for different concentrations of the nanoparticles in the Al2O3-water, CuO-water and hybrid nanofluids (Al2O3 + CuO/water). The heat transfer coefficient (HTC) has also been shown for different concentrations of the nanoparticles in the three nanofluids under study with heat flux for the nucleate boiling region.