Modelling Ignition, Combustion, and Pollutant Emissions

Abstract In this chapter, the ignition, combustion, and pollutant formation of solid fuel particles under different operating conditions are investigated using detailed numerical simulations. First, coal and biomass combustion in a laminar flow reactor configuration are compared, showcasing similar combustion characteristics between coal and biomass. Then, particle/particle interaction effects in the particle group configuration are investigated, indicating later ignition time and flame opening behaviour in higher particle number densities. Particle/chemistry/turbulence interactions are also studied in particle cloud combustion under isotropic turbulence, where ignition is found to occur most likely outside of particle clusters. To assess the reduced-order flamelet models for solid fuel combustion, the optimal estimator concept is employed using the generated dataset, revealing that modelling errors increase near particles. Finally, NO $$_x$$ x formation during solid fuel combustion is analysed. The highest NO $$_x$$ x formation is found to occur near the particle groups around stoichiometric mixtures. Important pathways for NO $$_x$$ x formation under different operating conditions are studied, revealing the dominance of the fuel-NO $$_x$$ x pathways.