Computational Modelling of a Tangentially Fired Boiler With Deposit Formation Phenomena

Abstract

Any complete CFD model of pulverised coal-fired boiler needs to consider ash deposition phenomena. Wall boundary conditions (temperature and emissivity) should be temporally corrected to account for the effects of deposit growth on the combustion conditions. At present voluminous publications concerning ash related problems are available. The current paper presents development of an engineering tool integrating deposit formation models with the CFD code. It was then applied to two tangentially-fired boilers. The developed numerical tool was validated by comparing it with boiler evaporator power variation based on the on-line diagnostic system with the results from the full CFD simulation.

A validation of computational fluid dynamics temperature distribution prediction in a pulverized coal boiler with acoustic temperature measurement

“…All the results demonstrated in this work correspond to wall emissivity equal to 0.7. More detailed description of thermal wall boundary conditions can be introduced by implementation of deposition model with thermal properties submodel [36].…”

“…During real boiler operation non-stationary process of deposition formation causes spatial changes in the temperature and emissivity of the water-wall surface between soot blower activities. More detailed description of thermal wall boundary conditions can be introduced by implementation of deposition model with thermal properties sub-model [36].…”

“…We have to emphasize that during real boiler operation temperature and emissivity vary with time and spatially due to water-wall slagging and soot blowers operation. This phenomena can be included in the simulations by implementing deposition model with thermal properties submodel [36]. Fig.…”

Simulation of heat transfer in combustion chamber waterwall tubes of supercritical steam boilers

“…presented numerical modelling of boiler superheater that takes into account deposit formation on heating surfaces. Modliński (2014) presented CFD calculation for similar problems focused on boiler combustion chamber.…”

CFD simulations of heat transfer in internally helically ribbed tubes

“…Combustion and flow of flue gases with fly ash and deposit formation on superheaters outer surface have been recently presented in many studies, e.g. by Modliński (2014), Nowak-Woźny et al (2013) and Wacławiak and Kalisz (2014). Other studies include numerical modelling and mathematical models that describe fluid and thermal flow of steam and flue gas through multi-pass exchangers, such as superheaters.…”