Effect of flame spray coating on falling film evaporation for multi effect distillation system

Abstract Horizontal tube falling film evaporators find various applications like multi effect distillation for sea water desalination, power and process applications, refrigeration applications, etc. In this system, latent heat released inside the tube due to condensation is transferred to the falling film on the tube surface resulting in convective evaporation. Among many heat transfer enhancement techniques, thermal spray coatings enjoy diverse applications with economic advantage for commercial applications. This paper focuses on Computational Fluid Dynamic(CFD) analysis of falling film evaporation of water on horizontal tubes under the influence of gravity at vacuum. ANSYS Fluent with VOF two-phase model is used for the falling film studies on the horizontal tube. Half section of the tube is modeled with gravitational flow of sea water from the top. This model is used to predict the enhancement in convective evaporation on thermal spray coated tube surface with varying roughness. These CFD results are...