Modelling for post-dryout heat transfer and droplet sizes at low pressure and low flow conditions

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · International Communications in Heat and Mass Transfer

DOI:https://doi.org/10.1016/0735-1933(96)00060-7· OSTI ID:372285

Jeong, H Y; No, H C ^[1]

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1. Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering

A correlation describing the initial droplet size just after the CHF position at low mass flux is suggested through regression analysis. The history-dependent post-dryout model of Varone and Rohsenow replaced by the Webb-Chen model for wall-vapor heat transfer is used as a reference model in the analysis. In the post-dryout region at low pressure and low flow, it is found that the suggested one-dimensional mechanistic model is valid only in the churn-turbulent flow regime (j*{sub g} = 0.5 {approximately} 4.5). It is also suggested that the droplet size generated from the churn-turbulent surface is dependent not only on the pressure but also on the vapor velocity. It turns out that the present model can predict the measured cladding and vapor temperatures within 20% and 15%, respectively.

• OSTI ID: 372285
• Journal Information: International Communications in Heat and Mass Transfer, Journal Name: International Communications in Heat and Mass Transfer Journal Issue: 6 Vol. 23; ISSN 0735-1933; ISSN IHMTDL
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
COOLING
DRYOUT
HYDRODYNAMICS
LOSS OF COOLANT
REACTOR CORES