Experimental study of pool boiling heat transfer on copper surfaces with Cu-Al2O3 nanocomposite coatings

The current growth in nanoscience created a deep space of research for modern technology in the field of energy conservation by reducing the energy dissipation from the energy conversion applications. The boiling heat transfer enhancement is an important and advanced field of research to increase the performance of energy conversion applications. The pool boiling heat transfer performance of saturated DI water at atmospheric pressure is examined experimentally on copper surfaces with Cu-Al2O3 nanocomposite coatings, as these particles have higher thermal conductivity. The nanocomposite coatings are developed by a single-step electrochemical deposition technique. This technique provides an easy control on surface properties like porosity and coating thickness. The deposition method is studied carefully and responsible surface morphology parameters are reported. The boiling heat transfer coefficient (BHTC) and critical heat flux (CHF) are improved considerably for nanocomposite coatings. The maximum critical heat flux of 1852 kW/m(2) and heat transfer coefficient of 199 kW/m(2 )K are found to be 72.5% and 273% higher than that of bare surface, respectively. The mechanism for pool boiling heat transfer enhancement with Cu-Al2O3 nanocomposite coated surfaces engages several effects like improvement in surface roughness, activation of larger number of nucleation sites, increase in porosity, and improved surface wettability.