ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
A Phenomenological Model of Dryout With Circumferentially Varying Heat Flux
Sinopsis
The Butterworth model for azimuthal mass transfer within a liquid film has been incorporated in to a
phenomenological model of annular film dryout. The modified algorithm has been fitted to experimental burnout
values from the published literature. These Critical Heat Flux (CHF) measurements relate to tubes subject to
azimuthally non-uniform heat flux which replicates the conditions found in fired boilers. The combined
models accurately predicted the CHF with an average error and RMS error of 0.8 % and 3.0 % respectively. This
supports the validity of the underlying mass transfer model. The best fit for the film-spreading coefficient was
0.3 mm. This is lower than the 0.9 mm suggested in the original work. There is some evidence in the data to
show the coefficient is not constant and depends on flow conditions. However the number of data points is too
small to allow a definitive conclusion on this point.
PALABRAS CLAVE:
Two-phase/Multiphase flow, Boiling and evaporation