Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Computational Assessment of a Gas-Liquid Pipe System on the fluid-dynamics of a high-temperature sulfidation corrosion mechanism
Submission Author:
Diogo Dantas Ribeiro , SP
Co-Authors:
Fernando César Oliveira, João Neto, EDUARDO OLIVEIRA, Diogo Dantas Ribeiro
Presenter: Diogo Dantas Ribeiro
doi://10.26678/ABCM.COBEM2017.COB17-1884
Abstract
Sulfidation corrosion mechanisms are strongly influenced by flow nature and distribution based on velocity fields, phases concentration and composition. On higher temperatures the vapour phase plays a major role on corrosion cracking evolution considering it's fraction of hydrogen sulfide and the conditions for wall effective collisions of sulfur components. This work focuses on the fluid dynamics of a gas-liquid flow through a computational approach regarding a carbon steel pipe system located in the feed section of an industrial fired heater. The main objective is to observe and analyze the flow characteristics that contributed to a local failure in the upstream vicinities of a tee connection mostly due to sulfidation corrosion. Based on a process simulation developed with Hysys® that supplied the two-phase flow characteristics and stream composition, translating an equilibrium condition, a numerical approach through CFD is structured. A block hexahedrical mesh was structured using Ansys ICEM-CFD®, being the two-phase fluid dynamics transient solution obtained with solver Ansys Fluent® through a Multi-fluid VOF and k-ω SST approach. For the accounting of Hydrogen Sulfide and Hydrogen transports on each phase, a decoupled multicomponent solution was adopted. The results showed that alterations on velocity profiles, phases volume and species fractions occurred as a consequence of flow direction changes sourced by a declined pipe transition and re-fueled by a tee reducing connection. This leaded a swirled and transitional flow on the vicinities of the failure region which established the conditions for the occurrence of sulfidation corrosion.
Keywords
CFD, Two-phase Flow, Sulfidation Corrosion, Transient analysis, Decoupled Multicomponent Approach
