Assessment of a model with char attrition for a bubbling atmospheric fluidized-bed combustor

2004-05-01
Gogebakan, Y
Selçuk, Nevin
A comprehensive model, previously developed and tested for prediction of behavior of continuous fluidized-bed combustors, is extended to incorporate char attrition and is applied to the simulation of a 0.3 MegaWatt (MW) atmospheric bubbling fluidized-bed combustor burning lignites with high Volatile Matter/Fixed Carbon (VM/FC) ratios in their own ashes. The effect of this incorporation is assessed by comparing the predictions of the model with and without attrition with measurements. Favorable comparisons obtained between predicted and measured temperature and concentration profiles and carryover char particle size distributions imply that these parameters are not sensitive to char attrition for lignites and the operating conditions under consideration. However, comparisons between combustion efficiencies predicted with and without char attrition and those obtained from measurements show that consideration of char attrition is essential for accurate prediction of combustion efficiencies.
COMBUSTION SCIENCE AND TECHNOLOGY

Suggestions

Modeling of NOx emissions from fluidized bed combustion of high volatile lignites
Afacan, Onur; Gogebakan, Yusuf; Selçuk, Nevin (2007-01-01)
A comprehensive model, previously developed and tested for prediction of behavior of continuous fluidized bed combustors is extended to incorporate NOx formation and reduction reactions and applied to the simulation of Middle East Technical University (METU) 0.3 MW Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) burning lignites with high Volatile Matter/Fixed Carbon (VM/FC) ratios in their own ashes. Favorable comparisons are obtained between the predicted and measured temperatures and concentrations ...
Mathematical Modeling of a Bubbling Fluidized Bed Combustor Cofired with Lignite and Biomass
Külah, Görkem; Selçuk, Nevin (2010-01-01)
A comprehensive system model of fluidized bed combustor, previously developed and tested for the prediction of combustion behavior of fluidized bed combustors fired with lignite was extended for the modeling of cofiring of lignite with biomass by incorporating volatile release, char combustion, and population balance for biomass. The model predictions were validated against measurements taken on a Middle East Technical University 0.3 MWt Atmospheric Bubbling Fluidized Bed Combustor fired with lignite only, ...
Simulation of circulating fluidized bed combustors firing indigenous lignite
Özkan, Mert; Selçuk, Nevin; Department of Chemical Engineering (2010)
A comprehensive model, previously developed for a rectangular parallelepiped shaped 0.3 MWt circulating fluidized bed combustor (CFBC) fired with high calorific value coal burning in sand and validated against experimental data is adapted to cylindrical configuration and is extended to incorporate NOx formation and reduction reactions and pressure drops around cyclone, downcomer and loop seal. Its predictive accuracy is tested by applying it to the simulation of Middle East Technical University (METU) 150 k...
Evaluation of an improved code for the performance of AFBCs
Selçuk, Nevin; Oymak, O (1997-03-01)
In a previously developed system model, bed and freeboard models were coupled for the continuous combustion of lignite particles of widely varied size distributions, burning in their own ash in a fluidised combustor. This was modified to incorporate a) a procedure for faster computation of particle-size distributions (PSDs) without any sacrifice of accuracy; b) an energy balance on char particles, for determining temperature variation with particle size; and c) assumption of plug flow for the interstitial g...
Assessment of gas radiative property models in the presence of nongray particles
Ates, CİHAN; OZEN, Guzide; Selçuk, Nevin; Külah, Görkem (2018-01-01)
In this study, a radiation code based on the method of lines solution of the discrete ordinates method for the prediction of radiative heat transfer in nongray gaseous media is developed by incorporation of two different spectral gas radiative property models, banded spectral line-based weighted sum of gray gases (banded SLW) and gray wide band (GWB) approximation in the presence of nongray absorbing-emitting-scattering particles. The aim is to introduce an accurate and CPU efficient spectral gas radiation ...
Citation Formats
Y. Gogebakan and N. Selçuk, “Assessment of a model with char attrition for a bubbling atmospheric fluidized-bed combustor,” COMBUSTION SCIENCE AND TECHNOLOGY, pp. 799–818, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31048.