Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.34, No.5, 619-628, 1996
가압유동층 석탄연소로에서 압력이 연소특성에 미치는 영향
Effect of Pressure on the Combustion Characteristics in a Press- urized Fluidized Bed Coal Combustor
시스템의 공정변수를 예측할 수 있는 가압하의 유동층 석탄연소로의 모델을 전개하였으며 본 모델을 사용하여 반응기 압력의 변화에 따른 시스템의 성능(탄소연소효율, 층내 탄소분율, 생성가스의 조성)을 넓은 범위에 걸쳐 분석하였다. Gel-dart B군에 속하는 석탄연소로 기포유동층의 거동은 압력의 변화에 의해 거의 바뀌지 않았다. 높은 유속 및 낮은 층온도의 조건에서 가압에 의한 효율의 이득이 크게 나타났으며 700℃의 층온도 조건에서는 15atm으로 가압함으로써 약 5%의 효율을 증가시킬 수 있다. 가압을 하면 산소의 농도증가로 탄소연소효율이 증대되지만 층내 탄소함량은 압력에 따라 2배 미만의 범위에서 증가하였다.
The effect of system pressure on the performance of a pressurized fluidized bed coal combustor(carbon combustion efficiency, bed carbon loading, gaseous concentration profile) has been studied by a PFBC model. The behavior of bubbling bed of Geldart B group does not change by pressurization. The more increase in the carbon combustion efficiency can be obtained by pressurization at conditions of the lower temperature and higher gas velocities. At the bed temperature of 700℃, 5% increase in the carbon efficiency can be obtained with 15 atm. The carbon efficiency increases due to larger oxygen concen- tration, whereas the bed carbon loading also slightly increases with an in- crease in system pressure.
[References]
  1. Choi JH, Ph.D. Thesis, KAIST, Seoul, Korea, 1989
  2. Gibbs BM, Inst. Fuel. Symp. Ser., 1(A5.1), 10, 1975
  3. Arena U, D'Amore M, Massimilla L, AIChE J., 29, 40, 1983
  4. Chirone R, D'Amore M, Massimilla L, AIChE J., 31, 812, 1985
  5. Rajan RR, Wen CY, AIChE J., 26, 642, 1980
  6. Horio M, Wen CY, AIChE Symp. Ser., 74(176), 101, 1978
  7. Chen TP, Saxena SC, AIChE Symp. Ser., 74(176), 149, 1978
  8. Wells JW, Byrd JR, Krishnan RP, Proc. 7th Int. Conf. on FBC, I, 284-294, 1982
  9. Overturf BW, Reklaitis GV, AIChE J., 29(5), 813, 1983
  10. Horio M, Shibata T, Kadoguchi K, Muchi I, "Behavior of Entrained Particles in the Freeboard," Proc. 2nd China japan Symp., edited by Kwauk, M. and Kunii, D., 124-135, 1985
  11. Park D, Levenspiel O, Fuel, 61, 578, 1982
  12. Degang R, Baosheng J, Mingyao Z, "A Coal Combustion Model in Pressurized Fluidized Bed," Fluidized Bed Combusion, ASME, pp. 1177-1181, 1991
  13. Miccio M, Nastri V, Poletto M, "The Effect of System Pressure on Char Combustion in Fluidized Beds: Model Predictions," Fluidized Bed Combustion, ASME, pp. 1233-1243, 1991
  14. Wen CY, Yu YH, AIChE J., 12, 610, 1966
  15. Mori S, Wen CY, AIChE J., 21, 109, 1975
  16. Davidson JF, Harrison RD, "Fluidized Particles," Cambridge Univ. Press, 1963
  17. Kunii D, Levenspiel O, "Fluidization Engineering," 2nd ed., Chap. 6, Boston, Butterworth-Heinemann, 1991
  18. Kobayashi H, Arai F, Sunagawa T, Kag. Kog., 31, 239, 1967
  19. Haider A, Levenspiel O, Powder Technol., 58, 63, 1989
  20. Merrick D, Highley J, AIChE Symp. Ser., 70(137), 366, 1974
  21. Field MA, Gill DN, Morgan BB, Hawkseley PGW, "Combustion of Pulverized Coal," British Coal Utilization Research Association, Leatherhead, Chenev and Sons Ltd. Banbury, 1967
  22. Ross IB, Davidson JF, Trans. I. Chem. E., 60, 108, 1981
  23. Arthur JR, Trans. Faraday Soc., 47, 164, 1951
  24. LaNauze RD, Chem. Eng. Res. Des., 63(1), 3, 1985
  25. Shiao SY, Warchol JJ, Botros PE, "Coal Devolatization and Char Oxidation under Simulated PFBC Conditions," Fluidized Bed Combustion, ASME, pp. 1183-1190, 1991
  26. Wallman PH, Carlsson RCJ, "Fluidized Bed Combustion Kinetics at Elevated Pressures," Fluidized Bed Combustion, ASME, pp. 1517-1522, 1991
  27. Howard JB, Williams GC, Fine DB, Proc. 14th Int. Symp. on Combustion, The Combustion Institute, Pittsburgh, pp. 975-985, 1973
  28. Hoffmann AC, Yates JG, Chem. Eng. Commun., 41, 133, 1986
  29. Kunii D, Levenspiel O, Ind. Eng. Chem. Res., 29, 1226, 1990
  30. Adanez J, Abanades JC, Ind. Eng. Chem. Res., 31, 2286, 1992