In this paper two-phase multicomponent dispersed-film flow with phase transition (evaporation) and chemical reactions is considered. A mathematical model is presented. The closed system of equation includes mass conservation equations for each component of each phase (gas, drops, film), momentum and energy conservation for whole mixture. Also it includes equations for kinetics of the chemical reactions, evaporation and experimental correlations for drop entrainment and deposition of the near wall film. This system of equation was used for modeling of oil refinery tubular furnace.