Coupling of spectral thermal radiation model with a comprehensive system model for co-combustion of biomass in bubbling fluidized bed

Date

2023-02-01

Author

Yaşar, Mehmet Soner
Selçuk, Nevin
Külah, Görkem

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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 East Technical University (METU) 0.3 MWt BFBC. Comparisons between fluidized bed combustion (FBC) system models with and without radiation reveal that the spectral model improves the predictions only slightly. This is considered to be due to the very small temperature difference between the freeboard medium and hot refractory side walls which results in lower rates of heat transfer from the freeboard to the walls. Furthermore, radiative heat transfer in the freeboard is dominated both by combustion gases and particles.

Subject Keywords

Biomass, Bubbling fluidized bed combustors, Co-combustion, Radiative heat transfer, Spectral radiation

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85141392357&origin=inward
https://hdl.handle.net/11511/101458

Journal

Fuel

DOI

https://doi.org/10.1016/j.fuel.2022.126534

Collections

Department of Chemical Engineering, Article

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Assessment of improved banded model for spectral thermal radiation in presence of non-gray particles in fluidized bed combustors Yaşar, Mehmet Soner; Ozen, Guzide; Selçuk, Nevin; Külah, Görkem (2020-07-01) In this study, Bordbar's banded model is coupled with a 3-D radiation model based on method of lines (MOL) solution of discrete ordinates method (DOM) for modeling of radiative heat transfer in freeboard of METU 0.3 MWt ABFBC test rig where a typical Turkish lignite is fired with and without fly ash recycling. The accuracy and the computational efficiency of the model were assessed by benchmarking its predictions against banded SLW model. Furthermore, in order to show the effect of gas composition on predic...
Radiative Heat Transfer in the Dilute Zone of an Air-Fired Circulating Fluidized Bed Combustor and Its Oxy-Fired Retrofit Ozen, G.; Aydin, F.; Selçuk, Nevin (2016-01-01) A 2D radiation model based on method of lines (MOL) solution of discrete ordinates method (DOM) coupled with spectral line-based weighted sum of gray gases model (SLW) is developed to predict radiative heat fluxes along the dilute zone of the lignite-fired 150 kWt Middle East Technical University (METU) circulating fluidized bed combustor (CFBC) under both air-fired and oxy-fired conditions. The dilute zone is treated as an axisymmetric cylindrical enclosure containing a non-gray, absorbing-emitting-isotrop...
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...
Effect of recycle on radiative heat transfer in the freeboard of a fluidized bed combustor Selçuk, Nevin; Gogebakan, Yusuf (2005-05-25) Effect of recycle on radiative heat transfer in the freeboard of a fluidized bed combustor is investigated by applying a previously developed 3-D radiation model to the prediction of incident radiative heat fluxes along the freeboard walls of lignite-fired 0.3 MWt Middle East Technical University (METU) Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) Test Rig and comparing its predictions with measurements. Freeboard is treated as a rectangular enclosure containing gray, absorbing, emitting and isotrop...

Citation Formats

M. S. Yaşar, N. Selçuk, and G. Külah, “Coupling of spectral thermal radiation model with a comprehensive system model for co-combustion of biomass in bubbling fluidized bed,” Fuel, vol. 333, pp. 0–0, 2023, Accessed: 00, 2023. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85141392357&origin=inward.