An improved physical model for flooding limited CHF under zero and very low flow conditions

Abstract

This paper presents an improved physical model to obtain comprehensive understanding of the CHF characteristics and to predict the CHF values under zero and very low flow conditions. The improved model gives reasonable agreements with the experimental data for CHF locations and values. It provides details of physical information on the CHF phenomena, and analytically confirms that the flooding is a triggering mechanism of the countercurrent annular flow CHF under zero and very low flow conditions. The present model reveals that the heat flux effect such as entrainment due to nucleation should be considered for the analysis of the flooding limited CHF as the L/D ratio decreases. (C) 1998 Elsevier Science Ltd.