Effect of the Aligned Flow Obstacles on Subcooled Flow Boiling in an Inclined Rectangular Channel

Abstract

The primary objective of this study is to investigate effect of aligned obstacles on heat removal capability of the core catcher cooling channel. In addition, it is aimed to understand the physical mechanism triggering flow boiling crisis affected by the aligned flow obstructions by means of visualization technique. This study presents experimental data for subcooled flow boiling of water at atmospheric pressure and low mass flux conditions. To investigate the heat transfer capability of the channel with the aligned studs, the down-scaled experiments for prototypical core catcher system were conducted. Effect of the various shapes of aligned studs on the boiling heat transfer characteristics has been experimented carefully. It was observed that the studs hindered the bubble release/sweeping process and the local heat flux between the studs was significantly lower than the crosssectional average heat flux. Local reversible dry patch appeared repetitively with exception of elliptic stud case, with which irreversible local dry patch appeared.