Dropwise Condensation Used In Mechanical Vapor Compression Desalination Plant-Computational Model

Abstract

Using ion-implanted metallic surfaces to induce a dropwise condensation improves the convective heat transfer coefficient significantly. The process of thermal desalination process, especially mechanical vapor compression (MVC) could be more effective by applying ion-implantation technology. This paper points to a possible reduction of heat transfer area of the main heat exchanger, using the specific MVC process. We showed in a selected MVC plant simulation model (mathematical model and developed software), that replacing filmwise by dropwise condensation could improve both main convective heat transfer processes (condensation and evaporation) by increasing the condensation heat transfer coefficient as well as the heat flux. For assumed improvement factor of dropwise condensation, comparing with filmwise condensation with the same MVC plant capacity, the reduction of main heat exchanger area is between 40% and 45%. The best improvement effect shows about a 10°C condensation-evaporation temperature difference.