Unsteady CFD analysis of kraft recovery boiler fly-ash trajectories, sticking efficiencies and deposition rates with a mechanistic particle rebound-stick model

摘要

This work presents a CFD model of a transversally-periodic bundle of four in-line tubes of a kraft recovery boiler bank for ash deposition calculations. The flue gas was laden with discrete solid ash particles. Particle contact and sticking-rebound mechanics were used. The ash deposition parameters (arrival rate, sticking efficiency, deposit rates) were computed locally, studying the dependency on the particle diameter. Emphasis was put regarding grid resolution, unsteady flow solving, and the differences observed among different tubes and locations.