Modelling of in-tube binary mixtures condensation in annular-mist flow with entrainment and deposition.

Mixtures condensation is widely encountered in liquefaction of natural gas process, refrigeration systems and other chemical and power generation industries. The study of the two-phase condensation region is of importance for the design of condensers, especially those employing multicomponent mixtures. This work presents a one-dimensional, three-field model to simulate the annular-mist flow regime considering a liquid film, droplets and a gas core. Considering the mass transfer resistance and the droplets interchange, the mass and species equations for each phase, the momentum and energy equations are solved for the in-tube condensation process of binary mixtures. The model is validated by experimental data from the literature. The flow characteristics, the compositions and temperatures in each field are analysed. The effect of the droplet interchange on the heat transfer is also investigated.