Numerical analysis of water purification processes in closed loop systems

This work is devoted to the development of a numerical approach to modeling the stage of "fine" filtration of the aquatic environment, following after passing of water through mechanical filters. At this stage of purification, the aquatic environment is subjected to electromagnetic or thermal effects. For the analysis of cleaning processes, mathematical models of fluid flow are proposed, taking into account thermal effects, the evolution of pollutant concentration with consideration of developed convection-diffusion processes in the presence of a quasi-static electric field. To describe the flow of an aqueous medium containing particles of solid fine impurities, a quasi-hydrodynamic model is used, supplemented by the equations of convection-diffusion-reaction. The numerical implementation of the model in the case of three-dimensional Cartesian geometry is based on the finite volume method on irregular tetrahedral and prismatic meshes and is focused on the use of parallel computing. As examples of the use of the developed technology of computer modeling, the problems of electromagnetic cleaning of the aquatic environment and pollution of the electric heating element are considered. In the first task, the dependence of the pollutant concentration on time is calculated. It demonstrates the cleaning effect and allows us to estimate degree of cleaning depending on the parameters of the electric field. In the second task, the process of scale formation and subsequent regeneration of the heating element is studied. The calculations performed show how the heating element is contaminated and how it is cleaned under the influence of hydrochloric acid. These data make it possible to refine the parameters of perspective closed-cycle plants, in which cycles of medium heating and regeneration of heating elements alternate.