@PhdThesis{duepublico_mods_00081596,
  author = 	{Meller, Dominik},
  title = 	{Large eddy simulation of reactive solid fuel systems using advanced flamelet approaches},
  year = 	{2024},
  month = 	{Mar},
  day = 	{01},
  keywords = 	{LES <Str{\"o}mung>},
  abstract = 	{The rising global energy demand poses a significant challenge in achieving CO2 reduction targets to mitigate global warming. Despite the ongoing progress in renewable energy technologies, such as hydrogen and iron oxidation/reduction, fossil fuels, particularly coal, continue to dominate the global energy mix. While efforts to transition to cleaner energy sources are expected to reduce coal demand, it is unlikely that coal usage will cease in the near future. Thus, the study of coal combustion and the implementation of effective emission reduction measures remain crucial. In the context of carbon-neutral power generation, carbon capture, utilization, and storage (CCUS) has become a pivotal technology. Additionally, the co-firing of coal with secondary fuel sources like ammonia or biomass shows promise for substantial CO2 emissions reduction. The primary objective of this work is to advance the comprehension and optimization of single and co-fired coal combustion through the application of sophisticated large eddy simulations (LES) using advanced models for coal combustion. This approach incorporates flamelet-based tabulation strategies within an Euler-Lagrange framework, offering broader applicability beyond coal to encompass also other solid fuels, such as biomass or iron. Studies are conducted on several pulverized coal flame configurations, ranging from laboratory-scale experiments to semi-industrial burner furnaces. Detailed LES and comparisons with experimental data demonstrate improved predictions of combustion characteristics, including temperature distributions and species concentrations. The investigations on a laboratory-scale coal jet flame highlight the significance of considering experimental artifacts and probing effects during simulation. Substantial deviations of up to 50 {\%} are found in the species concentration results, primarily attributed to the probing effect. In a separate study on the laboratory-scale coal jet flame, an investigation is conducted on the co-firing of coal and ammonia. This study represents one of the pioneering LES carried out on this topic. Initially, a novel reaction mechanism is generated, serving as the foundation for the subsequent flamelet table generation. The simulations show reasonable agreement with experimental data, improving predictions of OH and NH reaction zones when using the novel reaction mechanism. Another study examines a semi-industrial scale coal furnace equipped with a low-NOx burner, aiming to investigate the combustion characteristics and the processes of NOx formation. The results show an overall good agreement with experimental data. The incorporation of an additional transport equation for NO yields a substantial enhancement in the predictive accuracy of NO concentrations. This is achieved through the comprehensive consideration of NO production and destruction processes by splitting the NO source term into a formation and a rescaled consumption part. The developed simulation framework shows great promise in investigating cleaner combustion processes, including coal and ammonia or coal and biomass co-firing, and holds potential for future applications in technologies such as iron oxidation and reduction.},
  doi = 	{10.17185/duepublico/81596},
  url = 	{https://duepublico2.uni-due.de/receive/duepublico_mods_00081596},
  url = 	{https://doi.org/10.17185/duepublico/81596},
  file = 	{:https://duepublico2.uni-due.de/servlets/MCRFileNodeServlet/duepublico_derivate_00081107/Diss_Meller.pdf:PDF},
  language = 	{en}
}