A study on the effects of operational parameters on bed-to-wall heat transfer

Gungor A.

APPLIED THERMAL ENGINEERING, cilt.29, sa.11-12, ss.2280-2288, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Sayı: 11-12
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1016/j.applthermaleng.2008.11.008
  • Dergi Adı: APPLIED THERMAL ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2280-2288
  • Anahtar Kelimeler: Heat transfer, Circulating fluidized bed, Particle diameter, Suspension density, Modeling, CIRCULATING FLUIDIZED-BEDS, 2-DIMENSIONAL MODEL, COMBUSTION, COAL, CFB, MECHANISM, RISER
  • Akdeniz Üniversitesi Adresli: Hayır

Özet

In this study the effects of operational parameters on bed-to-wall heat transfer in CFBs are investigated such as solids volume fraction, particle diameter, suspension density, solid circulation rate. Based on a previously developed 2D CFB model, a modified cluster renewal model is used in this investigation. The model uses the particle-based approach (PBA) and integrates the hydrodynamics and combustion aspects. The study is also validated with experimental data. As a result of this study, it is observed that the bed-to-wall heat transfer coefficients are strongly dependent on particle diameter and solids concentration at the riser wall. The smaller particles result in higher heat transfer coefficients than larger particles for the same solids volume fraction values. The heat transfer coefficient increases with suspension density. However, at a constant suspension density, the superficial velocity does not have a significant influence on the heat transfer coefficient. PBA is satisfactorily adapted to cluster renewal model so that to define the bed-to-wall heat transfer mechanisms for the upper zone. (C) 2008 Elsevier Ltd. All rights reserved.