Multiphase Euler-Lagrange CFD simulation applied to Wet Flue Gas Desulphurisation technology

摘要

The gas and liquid hydrodynamics inside an Open Spray Tower has been simulated using a commercial CFD code, while a model that treats the absorption process Of SO2 has been developed and implemented in the software through dedicated modules. Besides SO2 absorption also evaporation of slurry droplets and droplet-wall interaction are considered, the latter modeled with an empirical correlation and implemented in a sub-module. The continuous gas phase has been modeled in an Eulerian framework, while the dispersed liquid phase with a Lagrangian approach by tracking a large number of particles through the computational domain. Physical absorption of SO2 has been modeled using dual-film theory and appropriate empirical and semi-empirical correlations. The model for aqueous phase chemistry considers instantaneous equilibrium reactions of eight dissolved species into a slurry droplet, namely: SO2.(aq), CO2.aq, H, OH-, HSO3-, SO32-, HCO3-, CO32-. The empirical droplet-wall interaction model handles impact, deposition and splashing events Occurring when a liquid particle hits an internal element of the scrubber. A pilot plant OST has been simulated and the numerical results show good agreement with the experimental values of pressure drop, temperature and Sulphur dioxide removal efficiency. (C) 2008 Elsevier Ltd. All rights reserved.