A stochastic model for prediction of Erosion-oxidation interaction on boiler grade steel Surfaces

Fly ash particles entrained in the flue gas
from boiler furnaces in coal-fired power stations can
cause serious erosive wear on steel surfaces along the
flow path. Such erosion can reduce significantly the
operational life of the boiler components. A
fundamentally-derived mathematical model
embodying the mechanisms of erosion involving
cutting wear, plastic deformation wear and effect of
temperature on erosion behaviour, has been developed
to predict erosion rates on the coal fired boiler
components such as boiler tubes, economizer and airpreheater assemblies at room and elevated temperature.
Various grades of steels, commonly used in the
fabrication of boiler components and published data
pertaining boiler fly ash has been used for modelling
the process. The model incorporates the tensile
properties of the target metal surface at room and
elevated temperatures, as well as the characteristics of
the ash particle dynamics in the form of impingement
angle, impingement velocity and composition of the
ash particle in terms of the silica content. The
mathematical model has been implemented in an userinteractive in-house computer code, (EROSIM–1 ) to
predict the erosion rates at room and elevated
temperature for various grades of steel normally used
in boiler components. The model predictions have
been found to be in good agreement with the published
data. The model will be calibrated in future with the
plant and experimental data generated from a high
temperature air-jet erosion testing facility. It is hoped
that the calibrated model will be useful to the power
plant industry for erosion analysis of boiler
components.