Experimental Investigation of Water Post-CHF Boiling in Forced Vertical Flow

摘要

This report started with a review of the published information on post-CHF phenomena and the experimental techniques. An experimental investigation of water film and transition boiling in a forced vertical up-flow channel has been conducted employing the calorimetric method. Film boiling was achieved by introducing the subcooled water flowing through a central bore of the cylindrical copper test section, which was heated up well above the Leidenfrost point in advance. The experimental range covered mass fluxes from 250 to 1000 kg/m exp 2 . s and inlet subcooling from 8 to 27 exp 0 C at pressures slightly above atmospheric conditions. Boiling curves were constructed using a lumped system approach. The results show that inlet subcooling and mass flux had the strongest influences on post-CHF boiling phenomena. As inlet subcooling and mass flux increased, the critical heat fluxes and the post-CHF boiling heat fluxes both increased. (ERA citation 10:002366)