Journal of the Korean Society of Combustion (한국연소학회지)

The Korean Society of Combustion (한국연소학회)
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Influence of Coal Conversion Model and Turbulent Mixing Rate in Numerical Simulation of a Pulverized-coal-fired Boiler

미분탄 보일러 연소 해석에서 석탄 반응 모델 및 난류 혼합 속도의 영향 평가

  • 양주향 (성균관대학교 기계공학부) ;
  • 김정은 (성균관대학교 기계공학부) ;
  • 류창국 (성균관대학교 기계공학부)
  • Received : 2015.06.30
  • Accepted : 2015.09.22
  • Published : 2015.09.30
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Abstract

Investigating coal combustion in a large-scale boiler using computational fluid dynamics (CFD) requires a combination of flow and reaction models. These models include a number of rate constants which are often difficult to determine or validate for particular coals or furnaces. Nonetheless, CFD plays an important role in developing new combustion technologies and improving the operation. In this study, the model selection and rate constants for coal devolatilization, char conversion, and turbulent reaction were evaluated for a commercial wall-firing boiler. The influence of devolatilization and char reaction models was found not significant on the overall temperature distribution and heat transfer rate. However, the difference in the flame shapes near the burners were noticeable. Compared to the coal conversion models, the rate constant used for the eddy dissipation rate of gaseous reactions had a larger influence on the temperature and heat transfer rate. Based on the operation data, a value for the rate constant was recommended.

Keywords

References

  1. J. Szuhanszki, S. Black, A. Pranzitelli, L. Ma, P.J. Stanger, D.B. Ingham, M. Pourkashanian, "Evaluation of the performance of a power plant boiler firing coal, biomass and a blend under oxyfuel conditions as a $CO_2$ capture technique," Energy Procedia, 37, (2013), 1413-1422. https://doi.org/10.1016/j.egypro.2013.06.017
  2. A.H. Al-Abbas, J. Naser, D. Dodds, "CFD modelling of air-fired and oxy-fuel combustion in a largescale furnace at Loy Yang A brown coal power station," Fuel, 102, (2012), 646-665. https://doi.org/10.1016/j.fuel.2012.06.028
  3. S. Park, J.A. Kim, C. Ryu, T. Chae, W. Yang, Y.J. Kim, H.Y. Park, H.C. Lim, "Combustion and heat transfer characteristics of oxy-coal combustion in a 100 MWe front-wall-fired furnace," Fuel, 106, (2013), 718-729. https://doi.org/10.1016/j.fuel.2012.11.001
  4. J.-E. A. Kim, C. Ryu, W. Yang, Y.J. Kim, H.Y. Park, H.P. Kim, "Assessment of combustion and heat transfer in Youngdong 100 MWe retrofit boiler for demonstration of oxy-coal combustion," International Journal of Greenhouse Gas Control, 17, (2013), 250-258. https://doi.org/10.1016/j.ijggc.2013.05.015
  5. C.R. Choi, C.N. Kim, "Numerical investigation on the flow, combustion and NOx emission characteristics in a 500 MWe tangentially fired pulverizedcoal boiler," Fuel, 88, (2009), 1720-1731. https://doi.org/10.1016/j.fuel.2009.04.001
  6. W.P. Adamczyk, S. Werle, A. Ryfa, "Application of the computational method for predicting NOx reduction within large scale coal-fired boiler," Applied Thermal Engineering, 73, (2014), 343-350. https://doi.org/10.1016/j.applthermaleng.2014.07.045
  7. T.J. Taha, A.F. Stam, K. Stam, G. Brem, "CFD modeling of ash deposition for co-combustion of MBM with coal in a tangentially fired utility boiler," Fuel Processing Technology, 114, (2013), 126-134. https://doi.org/10.1016/j.fuproc.2013.03.042
  8. C. Schuhbauer, M. Angerer, H. Spliethoff, F. Kluger, H. Tschaffon, "Coupled simulation of a tangentially hard coal fired $700^{\circ}C$ boiler," Fuel, 122, (2014), 149-163. https://doi.org/10.1016/j.fuel.2014.01.032
  9. M.Y. Hwang, C.H. Jeon, J.H. Song, G.B. Kim, S.M. Kim, M.S. Park, "Coal ash combustion simulation for 500 MW coal-firing boiler," Trans. Korean Soc. Mech. Eng. B, 35(9), (2011), 939-946. https://doi.org/10.3795/KSME-B.2011.35.9.939
  10. J. Andersen, C. L. Rasmussen, T. Giselsson, P. Glarborg, "Global combustion mechanisms for use in CFD modeling under oxy-fuel conditions," Energy & Fuels, 23, (2009), 1379-1389. https://doi.org/10.1021/ef8003619
  11. H. Xue, J. C. Ho, Y.M. Cheng, "Comparison of different combustion models in enclosure fire simulation," Fire Safety Journal, 36, (2001), 37-54. https://doi.org/10.1016/S0379-7112(00)00043-6
  12. D. Joung, K. Han, K.Y. Huh, H. Park, "Evaluation of the structural coal combustion model in a swirling pulverized coal combustor," J. Korean Soc. Combust., 17(2), (2012), 32-39
  13. J.H. Hong, J.A., Kim, C., Ryu, Y., Kim, "Evaluation of operational characteristics in a 500 MWe opposed- fired coal boiler using computational fluid dynamics," The 43th KOSCO Symposium, December 1st-2nd, 2011, 447-450.
  14. Fluent Inc., Fluent 6.3 user's guide, NH: Fluent Inc, Lebanon, 2006.
  15. S. Niksa, PC Coal Lab version 4.1: user guide and tutorial. CA: Niksa Energy Associates LLC, Belmont, 1997.
  16. C.Y. Wen, T.Z. Chaung, "Entrainment coal gasification modeling," Industrial & Engineering Chemistry Process Design and Development, 18(4), (1979), 684-695. https://doi.org/10.1021/i260072a020
  17. M.M. Baum, P.J. Street, "Predicting the combustion behaviour of coal particles," Combustion science and technology, 3, (1971), 231-243. https://doi.org/10.1080/00102207108952290
  18. W.P. Jones & R. P. Lindstedt, "Global reaction schemes for hydrocarbon combustion," Combustion and Flame, Vol. 73(3), (1988), 233-249. https://doi.org/10.1016/0010-2180(88)90021-1
  19. B.F. Magnussen, B.H. Hjertager, "On mathematical modeling of turbulent combustion with special emphasis on soot formation and combustion," In Symposium (International) on Combustion, 16(1), (1977), 719-729.
  20. B.M. Visser, J.P. Smart, W.L. Van de Kamp, R. Weber, R, "Measurements and predictions of quarl zone properties of swirling pulverised coal flames," In Symposium (International) on Combustion, 23(1), (1991), 949-955.
  21. J. Yang, J. A. Kim, J. Hong, M. Kim, C. Ryu, Y.J. Kim, H.Y. Park, S.H. Baek, "Effects of detailed operating parameters on combustion in two 500 MWe coal-fired boilers of an identical design," Fuel, 144, (2015), 145-156. https://doi.org/10.1016/j.fuel.2014.12.017