A1 Journal article (refereed), original research

Coarse Grain 3D CFD-DEM Simulation and Validation with Capacitance Probe Measurements in a Circulating Fluidized Bed


Publication Details
Authors: Stroh Alexander, Daikeler Alexander, Nikku Markku, May Jan, Alobaid Falah, von Bohnstein Maximilian, Ströhle Jochen, Epple Bernd
Publisher: Elsevier
Publication year: 2019
Language: English
Related Journal or Series Information: Chemical Engineering Science
Journal acronym: CES
Volume number: 196
Start page: 37
End page: 53
Number of pages: 17
ISSN: 0009-2509
eISSN: 1873-4405
JUFO-Level of this publication: 2
Open Access: Not an Open Access publication

Abstract

A cold flow circulating fluidized bed
(CFB) reactor is simulated under three fluidization velocities with the
coarse grain discrete element method (DEM) using two different
polydisperse particle systems namely glass beads and slightly coarser
sand particles of Geldart A-B range. Particle velocities and particle
concentration were measured by capacitance probe for the validation of
the numerical model. The simulations were carried out using a homogenous
drag model and a structure dependent drag model using the theory of
energy minimization multiscale method (EMMS). Numerical parameters like
grid resolution and computational time were investigated for the coarse
grain CFD-DEM model, suggesting a cell uniformity criteria that might
lead to more mesh independent results. The simulated macroscopic
quantities such as pressure profile are generally in good agreement for
all simulated cases using the EMMS model. Microscopic quantities such as
particles velocities and solids concentration are partially matched
well with the experimental data. The qualitative profiles of particle
velocity and particle concentration are in better agreement for the EMMS
model than for the homogenous drag model. The simulated reactor outflux
using glass beads is well matched with experiment. The simulated
reactor outflux with sand material is overestimated with EMMS model,
although not that strong as for the Gidaspow model, in comparison to
experimental measurements. One reason for the discrepancy is due to the
cluster diameter correlation that require further development to be
applicable in turbulent fluidization flow regime. Further model
improvements are discussed and solutions are provided.


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Last updated on 2020-20-03 at 10:03