Large eddy simulation of coal combustion
File(s)
Author(s)
Cavallo Marincola, Fabrizio
Type
Thesis
Abstract
In this work an in-house code for large-eddy simulations of coal combustion is developed and tested, with a special focus on the issue of modelling radiative heat transfer effects inside a furnace. An Eulerian-Lagrangian approach is used to describe the continuous gas phase and the discrete particle phase, with a two-way coupling between the two phases (implemented by another group member). The radiative transfer equation is solved using the discrete ordinates method, testing several different angular and spatial discretisation schemes. The spectral properties of the participating media are approximated with different grey gas models of varying complexity and accuracy. The accuracy of the radiative solver is initially assessed on simple idealised static cases in both two- and three-dimensions, and validated against benchmark data found in literature. The code is then integrated, parallelised and optimised with the LES flow and combustion solver, and used to simulate a large 2.4 MW coal combustion furnace. The results of the simulations are compared quantitatively against experimental data in terms of velocity, temperature, species distribution and solid particle analysis, showing a good agreement overall. A parametric study is then also performed on the variables and parameters of the radiation solver, showing great sensitivity on the outcome of the simulations in certain cases, further highlighting the importance of accurate radiation modelling for closed coal combustion furnaces.
Version
Open Access
Date Issued
2013-11
Date Awarded
2014-07
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Jones, William
Kempf, Andreas
Sponsor
Engineering and Physical Sciences Research Council
Publisher Department
Mechanical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)