Transient multiple particle simulations of char particle combustion

Abstract

Transient combustion behavior of char particle arrays in oxy-fuel atmosphere is analyzed with a resolved-particle two-dimensional simulation framework, considering both heterogenous and homogeneous chemical reactions. A range of various parameters is considered, such as particle distance, oxygen levels in the incoming flow, particle Reynolds number, and the particle arrangement. The analysis shows a large dependence on the distance between the particles and the location of each particle within the array. While particles facing the incoming flow show the highest burning efficiency, this efficiency drops as consecutive rows are considered. This effect is stronger for arrays, where the distance between the consecutive rows is less than three particle diameters. Within the range of particle Reynolds numbers considered in this study (1⩽Re⩽8), higher Reynolds numbers result in more efficient burning. The arrangement of the particles inside the array has a mild influence on the combustion behavior. As arrays with lower particle number densities are considered, the influence of the arrangement of the particle array diminishes. Finally, considering the temperature and the oxygen mass fraction around all the simulated particles in the parameter space provides insight towards the global relation between these variables, highlighting possible modeling directions.