Development and Validation of an Unsteady State Numerical Model of Fouling within a Crystalline Systern

Abstract

AbstractFouling is a phenomenon that threatens the sustainability of thermal and membrane desalination processes. The deposition of fouling material on the heatlmass transfer surface increases the amount of energy required for operation. Traditional fouling research has focused on experimental investigations that provide limited results and macroscopic assessment of the process. This research uses computational fluid dynamics (CFD) to model the transient nature of fouling and obtains an insight into the intricate interactions of the variables that influence fouling on a local scale.The authors developed a Eulerian model describing both the induction and deposition processes of the crystallisation fouling mechanism. The detail provided by the CFD model demonstrated that scale growth has a considerable impact on the hydrodynamics of the system, and vice‐versa. The intricate relationships between the operating variables affect the hydrodynamics and boundary layer conditions, and impact on both the heat and mass transfer. The deposit growth causes a decrease in the thickness of the mass boundary layer, thus promoting transport towards the growing crystal layer. Validation of this model showed good agreement with experimental data in terms of its ability to predict local fouling behaviour and rates.