A comprehensive fluidized bed combustion model coupled with a radiation model

A freeboard model of an overall FBC system model where radiation between particle and gas is accounted for through Stefan-Boltzmann law was modified by incorporation of a radiation model based on method of lines solution of discrete ordinates method. The predictive accuracy of the coupled code was tested by comparing its predictions with measurements taken on a refractory-lined, hybrid, pilot scale FBC as well as with predictions of unmodified system model. Comparisons show good agreement particularly for the test with recycle of fine particles. Significance of using a rigorous radiation model was illustrated by validating its predictions against measurements available on an industrial scale fluidized bed boiler. It was concluded that coupling a rigorous radiation model with an overall FBC system model is essential for accurate prediction of the behaviour of industrial boilers characterized by low surface to volume ratio and relatively colder water walls.


Coupling of spectral thermal radiation model with a comprehensive system model for co-combustion of biomass in bubbling fluidized bed
Yaşar, Mehmet Soner; Selçuk, Nevin; Külah, Görkem (2023-02-01)
A previously developed 1-D comprehensive model for a bubbling fluidized bed combustor (BFBC) co-firing lignite with cotton residue and limestone is coupled with a 3-D spectral and gray radiation models utilizing method of lines (MOL) solution of discrete ordinates method (DOM). The performance of the coupled models is assessed by comparing their predictions of temperature profiles and gaseous emissions (i) with those of original FBC model without coupling and (ii) with the in-situ measurements from Middle E...
A comparative study of modeling of radiative heat transfer using mol solution of dom with gray gas, wide-band correlated-k, and spectral line-based weighted sum of gray gases models
Cayan, Fatma Nihan; Selçuk, Nevin (2007-01-01)
A radiation code based on the method of lines (MOL) solution of the discrete ordinates method (DOM) for the prediction of radiative heat transfer in nongray absorbing-emitting media was developed by incorporation of two different gas spectral radiative property models, wide-band correlated-k (WBCK) and spectral line-based weighted sum of gray gases (SLW) models. Predictive accuracy and computational efficiency of the code were assessed by applying it to one- and two-dimensional test problems and benchmarkin...
Advanced workflow for multi-well tracer test analysis in a geothermal reservoir
Bayer, Peter; AKIN, TAYLAN; Akın, Serhat (2022-05-01)
Interpretation of tracer tests in geothermal reservoirs is carried out by fitting the measured data either with simplified two-dimensional (2-D) analytical solutions or with complex numerical models. Available analytical solutions commonly only describe isotropic conditions in 1-D or 2-D, which is generally unsatisfactory to construct realistic reservoir models. Moreover, due to the large spatial and temporal scale of a tracer test in deep reservoirs, the concentration levels measured in the field are relat...
A 3-D radiation model for non-grey gases
Selçuk, Nevin (2009-02-01)
A three-dimensional radiation code based on method of lines (MOL) solution of discrete ordinates method (DOM) coupled with spectral line-based weighted sum of grey gases (SLW) model for radiative heat transfer in non-grey absorbing-emitting media for use in conjunction with a computational fluid dynamics (CFD) code based on the same approach was developed. The code was applied to three test problems: two containing isothermal homogenous/non-homogenous water vapor and one non-isothermal water vapor/carbon di...
A Novel System for Measuring Solids Dispersion In Circulating Fluidized Beds
Külah, Görkem; Bi, H T; Lim, C J; Grace, J R (null; 2008-05-08)
A novel, simple and accurate experimental measurement system with fast response was developed to measure transient local solid tracer concentration distributions to obtain information on solids mixing and dispersion in risers of circulating fluidized beds operating at a wide range of operating conditions. Phosphorescent-coated FCC particles, used as the tracer, were activated by high intensity UV light and injected at the return leg of high-density circulating fluidized bed (HDCFB) unit. The tracer concentr...
Citation Formats
D. E. Alagoz, G. Külah, and N. Selçuk, “A comprehensive fluidized bed combustion model coupled with a radiation model,” COMBUSTION SCIENCE AND TECHNOLOGY, pp. 910–926, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30974.