Enhancement of Saturated Boiling Heat Transfer by Using Coated Surfaces

Abstract

In this study, we investigated the influence of thermal conductance of a boiling surface on the pool boiling heat transfer to saturated liquid nitrogen at atmospheric pressure. A cooled sample was a copper sphere, 25 mm in diameter. The thermal conductance of the copper surface was changed by the ice layer and the frost layer coated on it. The experimental results show that the effects of ice layers on the copper surfaces on cooling curves and boiling heat transfer characteristics are remarkable. When a frost layer is used as a thermal insulation layer on the cooling surface, the heat flux in the transition boiling region increased markedly and both the critical heat flux and heat flux in the nucleate boiling region increased.