Effect of condition of heating surface on pool boiling heat transfer. On boiling for unwettable surface and grooving surface.

Abstract

Boiling heat transfer was investigated by experiment for grooving surfaces and some unwetted heating surfaces which were coated on the small copper surface with Teflon and some silicon materials. For a Teflon coated surface, the boiling curve showed the same characteristics as that of the copper surface, but the coefficient of heat transfer was considerable low in the nucleate boiling region. For some silicon coated surfaces, the boiling curve was much different from the usual heat transfer in pool boiling. The heat flux increased monotonously with the increase of the super heat and no critical heat flux and minimum heat flux were observed. For grooving surfaces, the critical heat flux was considerable low and observed at lower superheat than that in conventional boiling heat transfer.