Numerical Simulation on Steam-Water Film Direct Contact Condensation

Steam-water film interfacial energy and mass transfer mechanism of direct contact condensation is the basis for the optimization design of mixing condensers. Taking steam-water film direct contact condensation as the research object, a film interfacial condensation energy and mass transfer model was established based on the volume of fluid (VOF) model. The impact of varying steam and water mass flow rate ranging in 0.002-0.010 kg/s and 0.30-0.83 kg/s respectively, as well as the influence of flow pattern, on the heat exchange of steam-water film direct contact condensation were analyzed. Results show that the heat transfer coefficient increases with the water and steam mass flow rate. The steam mass flow rate has little influence than the water mass flow rate on direct contact condensation. Compared with the parallel flow,cross flow proves to be more favorable for the heat transfer process. Due to the increased interphase force and irregular shape of the water film, the risk of water film breakage increases in the countercurrent flow condition.