THERMAL SCIENCE

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Yibin Wang

,

Hexin Liu

,

Houzhang Tan

MODELLING OF INITIAL DEPOSITION OF BIOMASS ASH PARTICLES ON WALLS OF SUPERHEATER TUBES

ABSTRACT
Condensation of gaseous alkali chloride and sulphate and adhesion of molten ash particles are still an important issue of investigation and gaining more and more attention in biomass utilization. In this work the behaviours for formation of initial deposition layer and condensation of KCl(g) and K2SO4(g) were simulated nu-merically in a 2-D computational domain of an in-line 4×4 tube bundle. The sticking and rebound efficiency of incident particles, condensation rate of gaseous salts and ash deposition rate on both of the windward and the leeward sides of tubes were obtained through transient calculation cases. The ash deposition mass on the windward side of tubes is mainly from impaction and stickiness of large ash particles. The condensation rate of KCl(g) is two orders of magnitude higher than that of K2SO4(g) on both of the windward and the leeward side of tubes. The ash deposition rate and the condensation rate on the windward side of tubes are of equal importance. While on the leeward side of tubes the condensation of salt vapours is more dominant than the inertial impaction in the forming stage of initial layer.
KEYWORDS
condensation, biomass, ash particles, stickness, modelling
PAPER SUBMITTED: 2020-03-11
PAPER REVISED: 2020-04-25
PAPER ACCEPTED: 2020-05-10
PUBLISHED ONLINE: 2020-09-26
DOI REFERENCE: https://doi.org/10.2298/TSCI200311270W
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2020, VOLUME 24, ISSUE Issue 6, PAGES [3489 - 3499]
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Modelling of initial deposition of biomass ash particles on walls of superheater tubes

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence