Heat Transfer Model for Dispersed Flow Regime during Reflood

Abstract

A physical model with consideration of the radiative heat transfer was proposed to evaluate analytically the heat transfer and the steam temperature in the dispersed flow regime during reflood in LOCA. This model was used to predict Semiscale Mod-1 Test S-03-8 and FLECHT-SET Test 3105B instead of a purely empirical correlation which was included in the current reflood code. Comparison of the prediction by the model with those experimental data indicated that the model presented a good agreement with turnaround time, maximum temperature and steam temperature of the data. Comparison between the predictions by the model and the current code indicated that the model presented the ap-proximately similar prediction and specially at a higher elevation of a core rod presented a better prediction of turnaround time and maximum temperature, and that the model can be applied to a reflood analysis instead of the empirical correlation. But detailed studies on physical models for the inverted annular flow regime and the quenching are indispensable to obtain a better prediction all over the core area.