Improvement, validation and application of CFD]DEM model to dense gas-solid flow in a fluidized bed

Abstract Dense gas–solid flow with solid volume fraction greater than 10% and at moderate Reynolds number is important in many industrial facilities such as fluidized beds. In this work, the Euler–Lagrange approach in combination with a deterministic collision model is applied to a laboratory-scale fluidized bed. The fluid–particle interaction is studied using a new procedure called the offset method, which results in several numbers of spatial displacements of the fluid grid. The proposed method is highly precise in determining porosity and momentum transfer, thus improving simulation accuracy. A validation study was carried out to assess the results using this in-house CFD/DEM code against 5-s operation of a Plexiglas spouted-fluidized bed, showing good qualitative correlation of solid distribution in the bed and acceptable quantitative agreement of pressure drops at different positions in the bed. In view of high computing cost, special emphasis is placed on effective program design, such as application of advanced detection algorithm for particle–particle/wall collisions, the multi-grid method and parallel calculation. In this context, the influence of increasing the processor number, up to 36, on calculation efficiency was investigated.

[1]  Helmar Schubert,et al.  Grundlagen des Agglomerierens , 1979 .

[2]  Joel H. Ferziger,et al.  Computational methods for fluid dynamics , 1996 .

[3]  Yoshinobu Morikawa,et al.  Experimental Measurement of the Magnus Force on a Rotating Sphere at Low Reynolds Numbers , 1985 .

[4]  Liang-Shih Fan,et al.  Principles of gas-solid flows , 1998 .

[5]  Jochen Ströhle,et al.  Extended CFD/DEM model for the simulation of circulating fluidized bed , 2013 .

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

[7]  Agba D. Salman,et al.  Accurate measurement of particle impact parameters , 1999 .

[8]  Hertz.  On the Contact of Elastic Solids , 1882 .

[9]  M. Adams,et al.  Discrete particle-continuum fluid modelling of gas–solid fluidised beds , 2002 .

[10]  Jochen Ströhle,et al.  CO2 Capture Based on Chemical and Carbonate Looping , 2008 .

[11]  Poupak Mehrani,et al.  Investigation of electrostatic charge distribution in gas–solid fluidized beds , 2010 .

[12]  Jam Hans Kuipers,et al.  Mixing and segregation in a bidisperse gas-solid fluidized bed: a numerical and experimental study , 2004 .

[13]  Said Elghobashi,et al.  On predicting particle-laden turbulent flows , 1994 .

[14]  P. Saffman.  The lift on a small sphere in a slow shear flow , 1965, Journal of Fluid Mechanics.

[15]  Mingyao Zhang,et al.  DEM simulation of gas-solid flow behaviors in spout-fluid bed , 2006 .

[16]  H. Hertz.  Ueber die Berührung fester elastischer Körper. , 1882 .

[17]  Wenqi Zhong,et al.  Characterization of dynamic behavior of a spout-fluid bed with Shannon entropy analysis , 2005 .

[18]  Said Elgobashi,et al.  An Updated Classification Map of Particle-Laden Turbulent Flows , 2006 .

[19]  A. Ladd,et al.  Moderate-Reynolds-number flows in ordered and random arrays of spheres , 2001, Journal of Fluid Mechanics.

[20]  Joseph R. Davis.  Concise metals engineering data book , 1997 .

[21]  Ng Niels Deen,et al.  Review of discrete particle modeling of fluidized beds , 2007 .

[22]  J.A.M. Kuipers,et al.  Computational fluid dynamics for dense gas–solid fluidized beds: a multi-scale modeling strategy , 2004 .

[23]  Geir Anton Johansen,et al.  Determination of void fraction and flow regime using a neural network trained on simulated data based on gamma-ray densitometry , 1999 .

[24]  Anja R. Paschedag,et al.  CFD in der Verfahrenstechnik: Allgemeine Grundlagen und mehrphasige Anwendungen , 2004 .

[25]  Yutaka Tsuji,et al.  Lagrangian numerical simulation of plug flow of cohesionless particles in a horizontal pipe , 1992 .

[26]  Jam Hans Kuipers,et al.  Discrete element study of granulation in a spout-fluidized bed , 2007 .

[27]  Keizo Yabumoto,et al.  Spontaneous structures in three-dimensional bubbling gas-fluidized bed by parallel DEM–CFD coupling simulation , 2008 .

[28]  Yutaka Tsuji,et al.  Numerical simulation of two-dimensional fluidized beds using the discrete element method (comparison between the two- and three-dimensional models) , 1998 .

[29]  J. N. Fawcett,et al.  The oblique impact of elastic spheres , 1976 .

[30]  H. Walter,et al.  Simulation von Kraftwerken und Feuerungen , 2012 .

[31]  Sunun Limtrakul,et al.  DEM modeling and simulation of a catalytic gas–solid fluidized bed reactor: a spouted bed as a case study , 2004 .

[32]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[33]  Agba D. Salman,et al.  An experimental study of the elastic rebound of spheres , 2001 .

[34]  A. Yu,et al.  Discrete particle simulation of particulate systems: Theoretical developments , 2007 .

[35]  Ng Niels Deen,et al.  Validation of a Discrete Particle Model in a 2D Spout-Fluid Bed Using Non-Intrusive Optical Measuring Techniques , 2008 .

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

[37]  F. Maio,et al.  Comparison of contact-force models for the simulation of collisions in DEM-based granular flow codes , 2004 .