Influence of soot on radiative heat transfer in bubbling fluidized bed combustors

Date

2021-08-01

Author

Yaşar, Mehmet Soner
Selçuk, Nevin
Külah, Görkem

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

291
views

0
downloads

The effect of soot particles and aggregates on radiative heat transfer in bubbling fluidized bed combustors is investigated. For this purpose, a soot radiative property model based on Rayleigh scattering theory is coupled with in-house developed 1-D gray and spectral radiation codes and a 3-D spectral radiation code based on method of lines solution of discrete ordinates method for the application of (i) a 1-D slab problem involving combustion gases and soot and (ii) freeboard of a 0.3 MWt atmospheric bubbling fluidized bed combustion test rig including combustion gases, fly ash particles and soot. The predictions of the 1-D radiation code reveal that (i) Planck-mean soot radiative properties provide reasonably accurate radiative heat transfer predictions (ii) soot particle diameter and number of soot particles in an aggregate do not considerably influence the net wall heat fluxes and source terms as absorption coefficient of soot is not significantly affected by those parameters and is orders of magnitude higher than scattering coefficient. Application of 3-D radiation model to the test rig shows that soot significantly contributes to radiative heat transfer in the freeboards of bubbling fluidized bed combustors. Soot has a noticeable impact on radiation even at very low volume fractions.

Subject Keywords

Spectral thermal radiation, Soot, Fluidized bed combustors, Combustion gases, Fly ash particles

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85105574158&origin=inward
https://hdl.handle.net/11511/90817

Journal

Journal of Quantitative Spectroscopy and Radiative Transfer

DOI

https://doi.org/10.1016/j.jqsrt.2021.107711

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

Influence of spectral particle properties on radiative heat transfer in optically thin and thick media of fluidized bed combustors Ates, Cihan; Sen, Ozge; Selçuk, Nevin; Külah, Görkem (2017-12-01) In this study, influence of spectral particle properties on radiative heat transfer in the freeboard/dilute zone of fluidized bed combustors (FBCs) is investigated. The aim is to identify how important it is to involve spectral particle properties and to determine the predictive accuracy of gray Mie and gray Geometric Optics (GOA) approximations in optically thin and thick media by benchmarking their predictions against spectral solutions. For that purpose, input data required for modelling radiative heat t...
Significance of particle concentration distribution on radiative heat transfer in circulating fluidized bed combustors Ates, CİHAN; Selçuk, Nevin; Külah, Görkem (2018-02-01) In this study, effect of particle concentration distribution on radiative heat transfer in circulating fluidized bed combustors (CFBCs) is investigated. The aim is to identify how important it is to include axial and radial variations of particle concentration along the splash and dilute zones in radiative heat transfer calculations and to determine the predictive accuracy of simple OD and 1D approximations for particle concentration distribution in the riser by benchmarking their predictions against a semi...
Influence of bag filter ash to spectral thermal radiation in fluidized bed combustors Co-Fired with biomass Yaşar, Mehmet Soner; Selçuk, Nevin; Külah, Görkem (2021-09-01) Influence of fine particles collected in bag filter on spectral thermal radiation is investigated in the freeboard of a 0.3 MWt atmospheric bubbling fluidized bed combustion test rig where lignite, lignite/olive residue, and lignite/hazelnut shell blends are fired with limestone addition. For this purpose, a 3-D radiation code based on method of lines solution of discrete ordinates method coupled with banded one gas spectral line-based weighted sum of gray gases for spectral gas properties, Mie theory for s...
Influence of fly ash composition on non-gray particle radiation in combusting systems Ates, CİHAN; Selçuk, Nevin; Külah, Görkem (2018-08-01) In this study, chemical composition dependency of both radiative properties of ash particles and radiative heat exchange are investigated for conditions typically encountered in industrial coal-fired furnaces. For that purpose, chemical composition dependent / independent complex index of refraction models are utilized to evaluate (i) spectral particle absorption efficiencies, scattering efficiencies and asymmetry factors, (ii) particle cloud properties representing pulverized coal fired furnaces (PC-Fired)...
Influence of oxygen concentration on the sooting behavior of ethanol droplet flames in microgravity conditions Yozgatlıgil, Ahmet; Choi, Mun Young; Kazakov, Andrei; Dryer, Frederick L. (Elsevier BV, 2007-1) The influence of oxygen (O-2) concentration and inert on the sooting and burning behavior of large ethanol droplets under microgravity conditions was investigated through measurements of burning rate, flame temperature, sootshell diameter, and soot volume fraction. The experiments were performed at the NASA Glenn Research Center (GRC) 2.2 s drop tower in Cleveland, OH. Argon (Ar), helium (He), and nitrogen (N-2) were used as the inerts and the O-2 concentration was varied between 21% and 50% mole fraction a...

Citation Formats

M. S. Yaşar, N. Selçuk, and G. Külah, “Influence of soot on radiative heat transfer in bubbling fluidized bed combustors,” Journal of Quantitative Spectroscopy and Radiative Transfer, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85105574158&origin=inward.