화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Korean Journal of Chemical Engineering, Vol.19, No.6, 1043-1049, November, 2002
DOI10.1007/BF02707231  Export Citation
Temperature Fluctuations and Heat Transfer in a Circulating Fluidized Bed
Pyung-Seob Song, Yi-Yeong Jeong, Jong-Sung Yun, Gil-Su Choi, Yong Kang†, and Sang-Done Kim1
  • Department of Chemical Engineering, Chungnam National University, Daejeon 305-764, Korea
  • 1Department of Chemical Engineering, KAIST, Daejeon 305-701, Korea
E-mail:
Characteristics of temperature fluctuations and heat transfer coefficient have been investigated in the riser of a circulating fluidized bed (0.102 m ID and 4.0 m in height). Effects of gas velocity and solid circulation rate on the temperature fluctuations, suspension density and heat transfer coefficient between the immersed heater and the bed have been considered in the riser. To analyze the characteristics of temperature fluctuations at the wall of the riser, the phase space portrait and Kolmogorov entropy of the fluctuations have been obtained, and the relation between the temperature fluctuations and the heat transfer coefficient has been examined. It has been found that the heat transfer system becomes more complicated and irregular with decreasing gas velocity and increasing solid circulation rate or suspension density in the riser. The heat transfer coefficient and Kolmogorov entropy of the temperature fluctuations have decreased with increasing the superficial gas velocity, while they have increased with increasing the solid circulation rate or suspension density in the bed. The heat transfer coefficient has been well correlated in terms of the Kolmogorov entropy, suspension density as well as operating variables in the riser.
Keywords:Circulating Fluidized Bed;Heat Transfer Coefficient;Temperature Fluctuation;Kolmogorov Entropy
  1. Basu P, Chem. Eng. Sci., 45, 3123 (1990) 
  2. Basu P, Nag PK, Int. J. Heat Mass Transf., 30, 2399 (1987) 
  3. Bi H, Jin Y, Yu Z, Bai D, "An Investigation of Heat Transfer in CFB," in CFB Technol. III Eds. by Basu P., Horio, M. and Hasatani, M., 233 (1991)
  4. Cho YJ, Kim SD, Han GY, Korean J. Chem. Eng., 13(6), 627 (1996)
  5. Cho YJ, Namkung W, Kim SD, Park SW, J. Chem. Eng. Jpn., 27(2), 158 (1994) 
  6. Cho YJ, Song PS, Kim SH, Kang Y, Kim SD, J. Chem. Eng. Jpn., 34(2), 254 (2001) 
  7. Dou S, Herb B, Tuzla K, Chen JC, "Dynamic Variation of Solid Concentration and Heat Transfer Coefficient at wall of Circulating Fluidized Bed," in Fluidization ed. by O.E. Potter and D.J. Nicklin, Engineering Foundation, New York, 739 (1992)
  8. Fraley LD, Lin YY, Hsiao KH, Solbakken A, "Heat Transfer Coefficient in Circulating Fluidized Bed Reactor," Proc. 21st ASME/AIChE Joint Natl Heat Trasfer Conf., Paper No. S3-HT-92, Seattle, Washington (1983)
  9. Glicksman LR, "Circulating Fluidized Bed Heat Transfer," in CFB Technol., ed. by Basu, P. and Large, L.F., Pergamon Press, Toronto, 13 (1988)
  10. Grace JR, "Heat Transfer in Circulating Fluidized Beds," in CFB Technol. I ed. by Basu, P., Pergamon Press, NY, 63 (1986)
  11. Grassberger P, "Estimating the Fractal Dimensions and Entropies of Strange Attractors in Chaos, Nonlinear Science, Theory and Applications," ed. by Holden, A.V., Manchester University Press, 291 (1986)
  12. Han KS, Sung HJ, Chung MK, Int. J. Heat Mass Transf., 34, 69 (1991) 
  13. Huilin L, Gidaspow D, Bouillard JX, AIChE Symp. Ser., 91(308), 103 (1995)
  14. Kage H, Dohzaki M, Ogura H, Matsuno Y, Korean J. Chem. Eng., 16(5), 630 (1999)
  15. Kang Y, Song PS, Yun JS, Jeong YY, Kim SD, Chem. Eng. Commun., 177, 31 (2000)
  16. Kang Y, Song PS, Woo KJ, Jeong YY, Kim SD, HWAHAK KONGHAK, 35(6), 819 (1997)
  17. Kim JS, Woo KJ, Kang Y, Nam CH, Kim SD, J. Chem. Eng. Jpn., 34(2), 185 (2001) 
  18. Kim SH, Han GY, Korean J. Chem. Eng., 16(5), 677 (1999)
  19. Kim SJ, Cho YJ, Lee CG, Kang Y, Kim SD, Korean J. Chem. Eng., 19(1), 175 (2002)
  20. Kim SW, Ahn JY, Lee DH, Kim SD, Korean J. Chem. Eng., 18(4), 555 (2001)
  21. Leckner B, Andersson BA, Powder Technol., 70, 303 (1992) 
  22. Molerus O, Chem. Eng. Sci., 48, 761 (1993) 
  23. Nag PK, Moral MNA, "Prediction of Heat Transfer in Circulating Fluidized Beds," in CFB Technol., Eds. by Basu, P., Horio, M. and Hasatani, M., 253 (1991)
  24. Namkung W, Kim SD, Korean J. Chem. Eng., 16(4), 456 (1999)
  25. Rhodes MJ, Geldart D, Powder Technol., 53, 155 (1987) 
  26. Roux JC, Simoui RH, Swinney HL, Physica, 8D, 257 (1983)
  27. Shen X, Zhou N, Xu Y, "Experimental Study on Heat Transfer in a Pressurized CFB," in CFB Technol., eds. by Basu, P., Horio, M. and Hasatani, M., 451 (1991)
  28. Subbarrao D, Basu P, Int. J. Heat Mass Transf., 27, 487 (1986)
  29. Wang XS, Rhodes MJ, Gibbs BM, Geldart D, "Radial Temperature Distributionin a CFB Riser," HM3 (1996)
  30. Weimer RF, Bexler AD, Piettit RD, Wang SI, "Optimization of a 49MW CFB Combustor," in CFB Technol., eds. by Basu, P., Horio, M. and Hasatani, M., 341 (1991)
  31. Woo KJ, Kim JS, Kang Y, Kim SD, Chem. Eng. Technol., 24(8), 829 (2001) 
  32. Wu RL, Grace JR, Lim CJ, Chem. Eng. Sci., 45, 3389 (1990) 
  33. Wu RL, Grace JR, Lim CJ, Brereton CMH, AIChE J., 35, 1685 (1989) 
  34. VanderStappen MLM, Schouten JC, VanderBleek CM, AIChE Symp. Ser., 89(296), 91 (1992)