Modelling of the turbulent gas–particle flow structure in a two-dimensional circulating fluidized bed riser

Abstract The gas–particle turbulent flow in a circulating fluidized bed (CFB) riser is investigated numerically by large eddy simulation (LES) coupled with Lagrangian approach. The gas phase model is based on locally averaged two-dimensional Navier–Stokes equations (N–S Eqs.) for two-phase flow with fluid turbulence calculated by LES, in which the effect of particles on subgrid-scale (SGS) gas flow is taken into account. The particles’ motion is treated by a Lagrangian approach, in which the particles are assumed to interact through binary, instantaneous, and non-elastic collisions. The model predicts the heterogeneous particle flow structure and the gas and particle mean velocities and turbulent intensities. The gas turbulence induces particle lateral dispersion. The instantaneous gas turbulent intensity is attenuated by the formation of clusters, whereas the intensity is enhanced by the increase of gas–particle interactions. Globally, the presence of clusters enhances the gas turbulent intensity. Finally, the turbulent model is noticeably affected by an empirically assigned gas constant C k and it consistently predicts values of the gas and particle turbulent intensities higher than those predicted by Smagorinsky's method.

[1]  J. Deardorff.  A numerical study of three-dimensional turbulent channel flow at large Reynolds numbers , 1970, Journal of Fluid Mechanics.

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

[3]  T. Kajishima,et al.  Large-eddy simulation of turbulent gas–particle flow in a vertical channel: effect of considering inter-particle collisions , 2001, Journal of Fluid Mechanics.

[4]  Hamid Arastoopour,et al.  Numerical simulation and experimental analysis of gas/solid flow systems: 1999 Fluor-Daniel Plenary lecture , 2001 .

[5]  K. Squires,et al.  On the prediction of gas–solid flows with two-way coupling using large eddy simulation , 2000 .

[6]  Alex Hansen,et al.  Disorder and granular media , 1993 .

[7]  Aibing Yu,et al.  Numerical simulation of the gas-solid flow in a fluidized bed by combining discrete particle method with computational fluid dynamics , 1997 .

[8]  Ivo Kljenak,et al.  Two-dimensional large-eddy simulation of turbulent natural convection due to internal heat generation , 2001 .

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

[10]  Gilles Flamant,et al.  DEM-LES of coal combustion in a bubbling fluidized bed. Part I: gas-particle turbulent flow structure , 2004 .

[11]  Jam Hans Kuipers,et al.  On the origin of heterogeneous structure in dense gas-solid flows , 2005 .

[12]  G. Stephanopoulos,et al.  Chemostat dynamics of plasmid-bearing, plasmid-free mixed recombinant cultures , 1988 .

[13]  J. O. Hirschfelder,et al.  Application of the Virial Theorem to Approximate Molecular and Metallic Eigenfunctions , 1937 .

[14]  M. T. Mason,et al.  Two-Dimensional Rigid-Body Collisions With Friction , 1992 .

[15]  Shinichi Yuu,et al.  Numerical simulation of the high Reynolds number slit nozzle gas–particle jet using subgrid-scale coupling large eddy simulation , 2001 .

[16]  Gilles Flamant,et al.  Lagrangian approach for simulating the gas-particle flow structure in a circulating fluidized bed riser , 2002 .

[17]  Clusters and particle segregation in gas-solids flow through a vertical tube through a vertical tube , 1996 .

[18]  P. Sagaut.  BOOK REVIEW: Large Eddy Simulation for Incompressible Flows. An Introduction , 2001 .

[19]  X. S. Wang,et al.  Mechanistic study of defluidization by numerical simulation , 2004 .

[20]  J. Smagorinsky,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS , 1963 .

[21]  A. Veefkind,et al.  The rates of production of CO and CO2 from the combustion of pulverized coal particles in a shock tube , 1998 .

[22]  Jidong Lu,et al.  Turbulence structure of the solid phase in transition region of a circulating fluidized bed , 2000 .

[23]  Steven H. Frankel,et al.  Two-dimensional large eddy simulation of soot formation in the near-field of a strongly radiating nonpremixed acetylene–air turbulent jet flame , 1999 .

[24]  Hayakawa,et al.  Dynamical simulation of fluidized beds: Hydrodynamically interacting granular particles. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

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

[26]  P. Koutmos.  Simulations of localized extinction in turbulent CH4 jet flames using a Lagrangian model for reactedness , 2000 .

[27]  Masayuki Horio,et al.  THREE-DIMENSIONAL FLOW VISUALIZATION OF DILUTELY DISPERSED SOLIDS IN BUBBLING AND CIRCULATING FLUIDIZED BEDS , 1994 .

[28]  C.M.H. Brereton,et al.  AXIAL GAS MIXING IN A CIRCULATING FLUIDIZED BED , 1988 .

[29]  Rajamani Krishna,et al.  Experimental validation of Lagrangian-Eulerian simulations of fluidized beds , 2001 .

[30]  J. Kuipers,et al.  Discrete particle simulation of bubble and slug formation in a two-dimensional gas-fluidised bed: A hard-sphere approach. , 1996 .

[31]  C. Wen.  Mechanics of Fluidization , 1966 .

[32]  Lounes Tadrist,et al.  Experimental analysis of the gas-particle flow in a circulating fluidized bed using a phase Doppler particle analyzer , 1998 .

[33]  Herbert Weinstein,et al.  Flow characterization in high-velocity fluidized beds using pressure fluctuations , 1988 .

[34]  Lounes Tadrist,et al.  Numerical study of cluster formation in a gas–particle circulating fluidized bed , 2000 .

[35]  Dimitri Gidaspow,et al.  Hydrodynamics of fluidization using kinetic theory: an emerging paradigm: 2002 Flour-Daniel lecture , 2004 .

[36]  Bo G Leckner,et al.  Fundamentals of turbulent gas-solid flows applied to circulating fluidized bed combustion , 1998 .

[37]  Kyle D. Squires,et al.  Large eddy simulation of particle‐laden turbulent channel flow , 1996 .

[38]  Y. Tsuji,et al.  Discrete particle simulation of two-dimensional fluidized bed , 1993 .

[39]  Bjørn H. Hjertager,et al.  An experimental and numerical study of flow patterns in a circulating fluidized bed reactor , 1996 .

[40]  Tron Solberg,et al.  Comparison of multifluid and discrete particle modelling in numerical predictions of gas particle flow in circulating fluidised beds , 2004 .

[41]  Lounes Tadrist,et al.  Computational study of fluctuating motions and cluster structures in gas–particle flows , 2002 .

[42]  H. Nishikawa,et al.  Numerical simulation of air and particle motions in group-B particle turbulent fluidized bed , 2001 .

[43]  M. Lesieur,et al.  New Trends in Large-Eddy Simulations of Turbulence , 1996 .