INVESTIGATION AND MODELING OF COCURRENT DOWNFLOW CIRCULATING FLUIDIZED BED (DOWNER)

Abstract To simulate the gas and solids flow structure in downflow circulating fluidized beds or downer reactors, a two-dimensional two-phase turbulence hydrodynamic model (κ. — ϵ turbulence model) was developed. The influence of solid particles on the turbulence structure of the gas phase has been considered in deriving the hydrodynamic model. An improved numerical method (based on the SIMPLE method) is used for the flow model calculation. The predicted radial distributions or axial gas and particle velocities are in good agreement with the experimental data determined by LDV measurement. This turbulence hydrodynamic model provides a good description of the gas and solids flow structure in the downer.

[1]  D. Gidaspow,et al.  A bubbling fluidization model using kinetic theory of granular flow , 1990 .

[2]  Sankaran Sundaresan,et al.  Turbulent gas‐particle flow in vertical risers , 1994 .

[3]  Dimitri Gidaspow,et al.  Computation of flow patterns in circulating fluidized beds , 1990 .

[4]  W. Reynolds.  Computation of Turbulent Flows , 1975 .

[5]  Yong Jin,et al.  Hydrodynamics of cocurrent downflow circulating fluidized bed (CDCFB) , 1992 .

[6]  John R. Grace,et al.  High-velocity fluidized bed reactors , 1990 .

[7]  S. Patankar.  Numerical Heat Transfer and Fluid Flow , 2018, Lecture Notes in Mechanical Engineering.

[8]  J. Grace,et al.  Hydrodynamics of gas-solid fluidization , 1995 .

[9]  Hamid Arastoopour,et al.  Hydrodynamic analysis of dilute gas—solids flow in a vertical pipe , 1990 .

[10]  R. Jackson,et al.  Gas‐particle flow in a vertical pipe with particle‐particle interactions , 1989 .

[11]  Jennifer L. Sinclair,et al.  Dilute turbulent gas‐solid flow in risers with particle‐particle interactions , 1995 .

[12]  Brian Launder,et al.  Sensitizing the Dissipation Equation to Irrotational Strains , 1980 .

[13]  Mihail C. Roco,et al.  Particulate two-phase flow , 1993 .

[14]  F. Durst,et al.  Eulerian and Lagrangian predictions of particulate two phase flows , 1984 .

[15]  C. P. Chen,et al.  A turbulence closure model for dilute gas‐particle flows , 1985 .

[16]  R. Clift,et al.  Bubbles, Drops, and Particles , 1978 .

[17]  S. L. Soo,et al.  Fluid dynamics of multiphase systems , 1967 .

[18]  Yong Jin,et al.  Cocurrent downflow circulating fluidized bed (downer) reactors — A state of the art review , 1995 .

[19]  Cedric Briens,et al.  Application of fiber optic reflection probes to the measurement of local particle velocity and concentration in gas—solid flow , 1994 .

[20]  C. P. Chen,et al.  Modeling of confined turbulent fluid-particle flows using Eulerian and Lagrangian schemes , 1990 .

[21]  Said Elghobashi,et al.  A two-equation turbulence model for dispersed dilute confined two-phase flows , 1989 .

[22]  Yoshinobu Morikawa,et al.  LDV measurements of an air-solid two-phase flow in a vertical pipe , 1984, Journal of Fluid Mechanics.