Large eddy simulations of coal jet flame ignition using the direct quadrature method of moments

Publication Type dissertation
School or College College of Engineering
Department Chemical Engineering
Author Pedel, Julien
Title Large eddy simulations of coal jet flame ignition using the direct quadrature method of moments
Date 2012-08
Description The Direct Quadrature Method of Moments (DQMOM) was implemented in the Large Eddy Simulation (LES) tool ARCHES to model coal particles. LES coupled with DQMOM was first applied to nonreacting particle-laden turbulent jets. Simulation results were compared to experimental data and accurately modeled a wide range of particle behaviors, such as particle jet waviness, spreading, break up, particle clustering and segregation, in different configurations. Simulations also accurately predicted the mean axial velocity along the centerline for both the gas phase and the solid phase, thus demonstrating the validity of the approach to model particles in turbulent flows. LES was then applied to the prediction of pulverized coal flame ignition. The stability of an oxy-coal flame as a function of changing primary gas composition (CO2 and O2) was first investigated. Flame stability was measured using optical measurements of the flame standoff distance in a 40 kW pilot facility. Large Eddy Simulations (LES) of the facility provided valuable insight into the experimentally observed data and the importance of factors such as heterogeneous reactions, radiation or wall temperature. The effects of three parameters on the flame stand-off distance were studied and simulation predictions were compared to experimental data using the data collaboration method. An additional validation study of the ARCHES LES tool was then performed on an air-fired pulverized coal jet flame ignited by a preheated gas flow. The simulation results were compared qualitatively and quantitatively to experimental observations for different inlet stoichiometric ratios. LES simulations were able to capture the various combustion regimes observed during flame ignition and to accurately model the flame stand-off distance sensitivity to the stoichiometric ratio. Gas temperature and coal burnout predictions were also examined and showed good agreement with experimental data.
Type Text
Publisher University of Utah
Subject Cfd; Coal; Direct quadrature method of moments; Dqmom; Large eddy simulation; Particles
Subject LCSH Moments method (Statistics); Coal, Pulverized --Combustion -- Computer simulation; Eddies -- Computer simulation
Dissertation Institution University of Utah
Dissertation Name Doctor of Philosophy
Language eng
Rights Management Copyright © Julien Pedel 2012
Format Medium application/pdf (portable document)
Format Extent 6,721,420 bytes
Identifier etd3/id/1783
Source Original in Marriott Library Special Collections, TP7.5 2012 .P33 2012
ARK ark:/87278/s6hd89gb
ID 195472
setname ir_etd
Reference URL https://collections.lib.utah.edu/details?id=195472
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