Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
A thermal state variation of water droplets carried by a gas
flow during unsteady phase transformations at their surface,
with a purpose to explore optimum conditions for utilization of
phase transformation heat accumulated in humid flue gas has
been modeled. The importance of the case of phase
transformations of a “single droplet”, during conductive
heating, for a comparative evaluation of warming droplet
heating in different heat and mass transfer condition conditions,
has been shown. It has been confirmed that the thermal state
variation of droplets presented in the time scale expressed in
Fourier number is not dependant on water spray dispersity if
droplets are heated conductively. Intensity and duration of the
process of water vapor condensation on droplet surface is
significantly influenced by water temperature and spray
dispersity as well as flue gas temperature and its humidity. The
radiation flow absorbed by droplets depends on water spray
dispersity. It determines formation of a negative gradient
temperature field and can shorten duration of the condensation
mode.
