The use of pre-dried brown coals is one possibility of increasing the efficiencies of brown coal fired utility boilers. As a mean value an increase of 3-4%-points can be achieved. On the other hand the usage of such fuels leads to a modified combustion behaviour. Especially to look at this point a mathematical model including all model parameters was developed and tested. For this task the commercial software Fluent~(~R) was used. In the study different models and model parameters were tested, especially the influence of the kinetics for pyrolysis and char burnout, particle tracking procedures, radiation models and properties and others. For validation purposes experimental data was available by RWE trials, done in their industrial combustion chamber in Niederauβem. Detailed axial and radial profiles of temperature and species concentrations for different brown coals and a large variety of process parameters were used, The comparison between experimental and numerical data forms the main part of this paper. Thus, the validity of the developed model can be demonstrated.
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