CFD approach for unburned carbon reduction in pulverized coal boilers

Jun Li, Radosław Jankowski, Michał Kotecki, Weihong Yang, Dariusz Szewczyk, Artur Brzdekiewicz, Wlodzimierz Blasiak

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Low-NO x technologies are widely used in pulverized coal boilers, but they usually produce high levels of carbon in the fly ash. High levels of unburned carbon represent fuel loss, so the overall boiler efficiency is reduced. Additionally, the higher carbon content affects the suitability of fly ash for cement applications. The purpose of this paper is to provide a CFD approach for unburned carbon reduction by optimizing operating conditions. In this paper, three different boiler loads were simulated: 200 MW, 170 MW, and 140 MW. The air supply system was simulated previously for preparing as precise as possible boundary conditions. At last, the unburned carbon level of every burner was investigated, and the effects of residue residence time and the local fuel-air momentum ratio are discussed in detail. According to the predicted results, operating conditions and the residence time of the coal particles affects the unburned carbon level in fly ash. Operating conditions play a more significant role during the combustion process, while the residence time affects char burnout only when the burners location is low. Therefore, it is concluded that a cost-effective method could be developed for reducing the unburned carbon level in ash and correspondingly, the loss on ignition level. First, it is necessary to determine which burners are operating under poor conditions through CFD analysis. Then, the fuel air momentum ratios of those burners should be modified by changing the operating conditions, meanwhile increasing the residence time of coal particles to ensure complete combustion.

LanguageEnglish
Pages926-937
Number of pages12
JournalEnergy and Fuels
Volume26
Issue number2
Early online date27 Dec 2011
DOIs
Publication statusPublished - 16 Feb 2012

Fingerprint

Coal
Boilers
Computational fluid dynamics
Carbon
Coal Ash
Fuel burners
Fly ash
Ashes
Momentum
Air
Coal ash
Ignition
Cements
Boundary conditions
Costs

Keywords

  • pulverized coal boilers
  • unburned carbon
  • operating conditions

Cite this

Li, J., Jankowski, R., Kotecki, M., Yang, W., Szewczyk, D., Brzdekiewicz, A., & Blasiak, W. (2012). CFD approach for unburned carbon reduction in pulverized coal boilers. Energy and Fuels, 26(2), 926-937. https://doi.org/10.1021/ef201700a
Li, Jun ; Jankowski, Radosław ; Kotecki, Michał ; Yang, Weihong ; Szewczyk, Dariusz ; Brzdekiewicz, Artur ; Blasiak, Wlodzimierz. / CFD approach for unburned carbon reduction in pulverized coal boilers. In: Energy and Fuels. 2012 ; Vol. 26, No. 2. pp. 926-937.
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Li, J, Jankowski, R, Kotecki, M, Yang, W, Szewczyk, D, Brzdekiewicz, A & Blasiak, W 2012, 'CFD approach for unburned carbon reduction in pulverized coal boilers' Energy and Fuels, vol. 26, no. 2, pp. 926-937. https://doi.org/10.1021/ef201700a

CFD approach for unburned carbon reduction in pulverized coal boilers. / Li, Jun; Jankowski, Radosław; Kotecki, Michał; Yang, Weihong; Szewczyk, Dariusz; Brzdekiewicz, Artur; Blasiak, Wlodzimierz.

In: Energy and Fuels, Vol. 26, No. 2, 16.02.2012, p. 926-937.

Research output: Contribution to journalArticle

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AU - Li, Jun

AU - Jankowski, Radosław

AU - Kotecki, Michał

AU - Yang, Weihong

AU - Szewczyk, Dariusz

AU - Brzdekiewicz, Artur

AU - Blasiak, Wlodzimierz

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Li J, Jankowski R, Kotecki M, Yang W, Szewczyk D, Brzdekiewicz A et al. CFD approach for unburned carbon reduction in pulverized coal boilers. Energy and Fuels. 2012 Feb 16;26(2):926-937. https://doi.org/10.1021/ef201700a