Influence of surface wettability increase induced by Gamma-ray irradiation on critical heat flux in downward-facing flow boiling

摘要

To increase the surface wettability is a feasible way to enhance critical heat flux (CHF) according to some CHF theories and many previous researches. It is found that surface wettability of metal can be increased after the surface being irradiated by Gamma-ray irradiation and CHF in pool boiling can thus be enhanced. In this study, whether CHF in downward-facing flow boiling can be enhanced after the surface being irradiated by Gamma-ray is experimentally investigated. Copper surface and metal porous honeycomb plate are irradiated by Gamma-ray and then used in the downward-facing flow boiling experiments. However, the experiment results show that downward-facing flow boiling CHF is not enhanced even though the surface wettability of bare surface and metal porous honeycomb plate increase a lot. The reason is analyzed considering the characteristic of downward-facing flow boiling. (C) 2020 Elsevier Ltd. All rights reserved.