Mechanistic model for the prediction of water-subcooled-flow-boiling critical heat flux at high liquid velocity and subcooling

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Fusion Technology

OSTI ID:374455

Celata, G P; Cumo, M; Mariani, A; Zummo, G ^[1]

---

1. ENEA, Rome (Italy)

A new model is presented for the prediction of the critical heat flux (CHF) of subcooled flow boiling based on a liquid-sublayer dryout mechanism, i.e., the dryout of a thin, liquid layer beneath an intermittent vapor blanket due to the coalescence of small bubbles. The model focuses on the analysis of the CHF in subcooled flow boiling under conditions of very high mass flux and liquid subcooling, typical of fusion reactor thermal-hydraulic design, and is characterized by the absence of empirical constants always present in earlier models. Peripheral nonuniform heating and/or twisted-tape inserts are accounted for in the model, which was originally developed for uniform heating and straight flow. The simultaneous occurrence of the two events is also well predicted by the model. Although initially formulated for operating conditions typical of the thermal-hydraulic design of fusion reactor high-heat-flux components, the model is proven to be able to satisfactorily predict the CHF under more general conditions, provided local thermodynamic conditions of the bulk flow at the CHF are sufficiently far from the saturated state. 60 refs., 11 figs.

• OSTI ID: 374455
• Journal Information: Fusion Technology, Journal Name: Fusion Technology Journal Issue: 4 Vol. 29; ISSN 0748-1896; ISSN FUSTE8
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CALCULATION METHODS
CRITICAL HEAT FLUX
DESIGN
FLUID FLOW
MATHEMATICAL MODELS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
SUBCOOLED BOILING
THERMONUCLEAR REACTORS
WATER