ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
MODIFICATION OF THE DIFFUSION LAYER MODEL FOR CONDENSATION HEAT TRANSFER UNDER THE PRESENCE OF NONCONDENSABLE GASES
Abstract
A diffusion layer model has been modified with a turbulent diffusion coefficient to consider an effect of turbulent flow on condensation. The modified diffusion layer model is aimed to predict condensation heat transfer on vertical surfaces in the presence of noncondensable gases. Correlations of heat and mass transfer coefficient in the original diffusion layer model have been modified using the correlations to calculate heat and
mass transfer on a vertical surface for various flow conditions. The modified diffusion layer model can predict
local heat and mass transfer as well the averaged values using the correlations for local heat and mass transfer coefficient. The modified diffusion layer model has been implemented into the MARS code and validated against the database of several experiments which cover various conditions expected during a postulated severe accident. The modified diffusion layer model shows a good agreement with the experimental data on both of
forced convection flow and natural convection flow. Although there are some deviations in the entrance region, the model can predict a trend of heat transfer at the entrance region within a good agreement.