Effect of micro-/nano-porous thin film surfaces prepared by a hybrid method of etching and electrochemical deposition on pool boiling heat transfer performance

Abstract

Surfaces created using efficient and inexpensive methods are highly demanded in industrial applications of extremely high temperatures. In this study, Composite Nano-particle Coated Over CuO Filmed (CNCCF) surface is prepared through two processes, first through chemical etching to produce a thin film of CuO over bare Cu surface, and secondly deposition of Ni-Al2O3 composite nano-particle over CuO thin filmed copper surface by electrochemical deposition process. The completed CNCCF surface exhibits favorable characteristics for improved boiling heat transmission, such as wettability, roughness, porosity, etc. An experiment on pool boiling is conducted on the CNCCF and bare Cu surface. DI water at atmospheric pressure is used as the boiling fluid. Findings show that the CNCCF surface exhibits enhanced Critical Heat Flux (CHF) and Boiling heat Transfer Coefficient (BHTC) than bare Cu surface. The increased porosity, roughness, and other properties of the CNCCF surface are the cause of this improvement in CHF and BHTC. A high-speed camera is also used to monitor and analyze bubble behavior during boiling on all surfaces, including the Bare Cu. Further evidence for the enhancement of boiling heat transfer on the CNCCF surface comes from the nucleation site density, departure diameter, and frequency characteristics of bubbles.