화학공학소재연구정보센터
Korean Chemical Engineering Research, Vol.55, No.4, 548-555, August, 2017
접선연소식 보일러에서 미분탄 연소 시 공기 배분의 영향에 대한 전산해석연구
Numerical Simulation on the Effects of Air Staging for Pulverized Coal Combustion in a Tangential-firing Boiler
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초록
본 연구는 560 MWe급 접선연소식 미분탄 보일러에서 공기단계연소에 의한 연소 및 NOx 배출 특성과 슬래깅성에 대하여 분석한 것이다. 이를 위해 고급 석탄 연소 모델이 적용된 전산유체역학(CFD) 시뮬레이션을 이용하여 전체 연소공기의 당량비(SR)는 1.2로 고정하고, 버너 영역의 SR을 0.94에서 0.995까지 변화시켰다. 공기 배분의 변화에 따라 버너 영역 및 열교환기의 온도 및 전열량 분포가 변하지만 보일러의 전체 효율은 거의 동일하게 나타났다. 버너 영역의 SR이 0.94로 낮아지면 Fuel NO의 생성이 억제되어 절탄기 출구 NOx 배출량은 20% 감소하나, 미연분과 슬래깅성에는 큰 영향이 나타나지 않았다. 따라서, 이 보일러에서 NOx 배출 저감을 위해 공기배분을 조절하여 버너 영역의 SR를 낮추고 상부연소공기(OFA)의 값을 높여 운전하는 것이 타당함을 확인하였다.
This study investigated the influence of air staging on combustion and NOx emission in a tangential-firing boiler at a 560 MWe capacity. For air staging, the stoichiometric ratio (SR) for the burner zone was varied from 0.995 to 0.94 while the overall value was fixed at 1.2. The temperature and heat flux in the burner zone and upper furnace corresponded to the distribution of SR, while the total boiler efficiency remained similar. The NOx emission at the furnace exit was reduced by up to 20% when the SR in the burner zone decreased to 0.94. However, the amount of unburned carbon and slagging propensity was not noticeably influenced by the changes in the SR of the burner zone. Therefore, it was favorable to lower the SR of the burner zone for reduction of NOx emission.
  1. Seo SI, Park HY, Lee SN, Korean J. Air-Cond. Refrig. Eng., 21, 157 (2009)
  2. Okazaki K, Ando T, Energy, 22(2-3), 207 (1997)
  3. Man CK, Gibbins JR, Witkamp JG, Zhang J, Fuel, 84, 1290 (2005)
  4. Molina A, Eddings EG, Pershing DW, Sarofim AF, Prog. Energy Combust. Sci., 26, 507 (2000)
  5. Chae JO, Chun YN, Yi UY, Trans. Korean Soc. Mech. Eng. B, 17, 1556 (1993)
  6. Jang GH, Chang IG, Jeoung SY, Sun CY, Chon MH, Trans. Korean Soc. Mech. Eng. B, 1, 724 (1999)
  7. Yang JC, Sun R, Sun SZ, Zhao NB, Hao N, Chen H, Wang Y, Guo HR, Meng JQ, Fuel Process. Technol., 126, 266 (2014)
  8. Fan WD, Lin ZC, Kuang JG, Li YY, Fuel Process. Technol., 91(6), 625 (2010)
  9. Jang GH, Chang IG, Sun CY, Chon MH, Yang GM, J. Korean Soc. Combust., 1, 149 (1999)
  10. Sung Y, Moon C, Eom S, Choi G, Kim D, Fuel, 182, 558 (2016)
  11. Le Bris T, Cadavid F, Caillat S, Pietrzyk S, Blondin J, Baudoin B, Fuel, 86(14), 2213 (2007)
  12. Li S, Xu TM, Hui S, Wei XL, Appl. Energy, 86(9), 1797 (2009)
  13. Diez LI, Cortes C, Pallares J, Fuel, 87(7), 1259 (2008)
  14. Seo SI, Park HY, Kang DS, Jeong DH, Energy Eng. J., 19, 156 (2010)
  15. Yoon MJ, Lee BH, Song JH, Kim GB, Chang YJ, Jeon CH, Trans. Korean Soc. Mech. Eng. B., 34, 587 (2010)
  16. Kokkinos A, Wasyluk D, Brower M, Barna JJ, ASME International Joint Power Generation Conference, 2000.
  17. Kang KT, Song JH, Yoon MJ, Lee BH, Kim SM, Chang YJ, Jeon CH, Trans. Korean Soc. Mech. Eng. B, 11, 858 (2009)
  18. Lee SH, Park SC, Yim YJ, Kim HT, Korean Chem. Eng. Res., 34(1), 8 (1996)
  19. Lee SH, Lim H, Kim SD, Jeon CH, Korean Chem. Eng. Res., 52(2), 233 (2014)
  20. Barnes DI, CCC/147, IEA Clean Coal Centre, London UK, 43(2009).
  21. Jung B, Korean J. Chem. Eng., 13(6), 633 (1996)
  22. Scott DH, Energy Fuels, 15, 502 (2001)
  23. Wang HF, Harb JN, Prog. Energy Combust. Sci., 23(3), 267 (1997)
  24. Srinivasachar S, Helble J, Boni A, 23rd Symposium (International) on Combustion, 23, 1305-1312(1991).
  25. Lee BH, Kim SI, Kim SM, Oh DH, Gupta S, Jeon CH, Korean J. Chem. Eng., 33(1), 147 (2016)
  26. Modlinski NJ, Chem. Eng. J., 35, 361 (2014)
  27. Niksa S, Niksa Energy Associates LLC, Belmont, CA, United States, 1997.
  28. Jones WP, Lindstedt RP, Combust. Flame, 73, 233 (1988)
  29. Magnussen BF, Hjertager BH, 16th Symposium (International) on Combustion., 16, 719-729(1976).
  30. Wen CY, Chaung TZ, Ind. Eng. Chem. Process Des. Dev., 18, 684 (1979)
  31. Garba MU, Ingham DB, Ma L, Degereji MU, Pourkashanian M, Williams A, Fuel, 113, 863 (2013)
  32. Kalmanovitch DP, Frank M, Proceedings of Mineral Matter and ash deposition from coal, United Engineering Trustees Inc Santa Barbara, 89-101(1988).
  33. Srinivasachar S, Senior CL, Helble JJ, Moore JW, 16th Symposium (International) on Combustion, 1, 1179-1187(1992).