Deposition From Waxy Mixtures Under Turbulent Flow in Pipelines: Inclusion of a Viscoplastic Deformation Model for Deposit Aging(Abstract)

摘要

A mathematical model for solids deposition from multicomponent paraffinic mixtures is developed to simulate turbulent flow in pipelines. The model is based on the moving boundary problem formulation, with the liquid-deposit interface temperature held at the wax appearance temperature (WAT). {1,2} The deposit formation and growth is modeled primarily as a heat-transfer process, in which the shear stress causes changes in the deposit properties with time. The effect of shear stress on the growth and composition of the deposit-layer was incorporated via a viscoplastic model, {3} which is based on one-dimensional deformation of a cubical-cage, causing the "squeezing out" of a fraction of the liquid from the deposit.{4} The viscoplastic deformation model accounts for time-dependent variations in deposit composition, which is influenced by Reynolds number (or shear rate).