Effects of pressure on particle velocity profile in CFBS
Küçük Resim Yok
Tarih
2008
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
TuTech Innovation GmbH
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The pressure has a positive effect on the mixing conditions since increasing pressure value causes stronger turbulence in the riser which results in better mixing of particulate solids and gases. In this study the effects of pressure on particle velocity profile in CFBs is investigated based on previously developed 2D CFB hydrodynamic model which uses the particle-based approach. In the modeling, the CFB riser was analyzed in two regions: The bottom zone in turbulent fluidization regime was modeled in detail as two-phase flow which was subdivided into a solid-free bubble phase and a solid-laden emulsion phase. In the upper zone core-annulus solids flow structure was established. The pressure drop through the bottom zone was assumed to be equal to the weight of the solids and considered only in axial direction. In the upper zone, pressure drop due to the hydrodynamic head of solids was considered in axial direction while pressure drop due to solids acceleration was also considered in axial and radial directions. The model results compared fairly well with experimental data of axial pressure drop profiles and radial particle velocity profiles from the literature. The hydrodynamic behavior of CFB is greatly affected by the inlet bed pressure values. Increasing operating pressure led to a decrease in the difference between the particle velocity in the riser core region and the wall region probably due to increased turbulence.
Açıklama
9th International Conference on Circulating Fluidized Beds, CFB 2008, in Conjunction with the 4th International VGB Workshop on Operating Experience with Fluidized Bed Firing Systems -- 13 May 2008 through 16 May 2008 -- Hamburg -- 106582
Anahtar Kelimeler
Kaynak
CFB 2008 - Proceedings of the 9th Int. Conference on Circulating Fluidized Beds, in Conjunction with the 4th International VGB Workshop "Operating Experience with Fluidized Bed Firing Systems"
WoS Q Değeri
Scopus Q Değeri
N/A
