INVESTIGATION OF HYDRODYNAMICS, HEAT AND MASS TRANSFER SIMULTANEOUSLY IN LIQUID FILM FLOW ON INCLINED PLATES USING CFD APPLICATION

A two-phase flow CFD model using volume of fluid (VOF) method is presented for predicting the hydrodynamics, heat transfer and mass transfer of falling film flow on inclined plates, corresponding to the surface of texture of structured packing. Using the proposed CFD model the influence of solid surface microstructure, liquid properties and gas flow rate on flow behavior was investigated. From the simulated results it was shown that under the condition of no gas flow the liquid flow patterns are dependent on the microstructure of the plates, and proper micro structuring of the solid surface will improve the formation of a continuous liquid film. Increasing the wetted area results enhancement of heat and mass transfer from film. It was also found that liquid properties, especially surface tension, play an important role in determining the thin film pattern. However, there are very different liquid film patterns under the action of gas flow. Thinner liquid films break easily, but thicker liquid films remain continuous even at higher gas flow rate, which demonstrates that all factors affecting the liquid film thickness will affect the liquid film patterns under conditions of counter-current two-phase flow. Finally it was found that any changes in liquid film patterns influence too much on heat and mass transfer from the film.

Keywords:

Structured packing , Hydrodynamics , Heat transfer , Mass transfer , CFD