Effect of nano-particle coating techniques of SiO2 on improvement of Critical Heat Flux

In this study, two methods of nano-particle coating, by boiling and electrophoretic, have been used to investigate the effect of surface modification on the Critical Heat Flux of stainless steel plates. In each of these two methods, the coating was performed for 20, 40, and 60 minutes while other parameters remained constant. The SEM1 and EDS2 images were captured and then the contact angles were measured using the Stadler technique to study the effect of surface properties on Critical Heat Flux.  Finally, the boiling curves of the hydrophilic and superhydrophilic surfaces were obtained and then the Critical Heat Flux (CHF) is determined. The CHF values were compared with the existing experimental data and empirical correlations. It was found that the CHF for nanoparticle coating by pool boiling, is significantly higher than those of electrophoretic coating. Also, a comparison of the present Critical Heat Flux results with those obtained by the empirical correlations that are a function of surface properties showed better agreement