Coal particle volatile combustion and flame interaction. Part I: Characterization of transient and group effects

Detailed simulations for flamelet modelling of SOx formation from coal

“…Recently a number of fully-resolved simulations of single particles [8][9][10][11] and coal particle arrays [12][13][14] have been performed. Vascellari et al [8] pioneered the work on fully-resolved simulations of single coal particle ignition experiments [15] for flamelet modelling.…”

“…The work confirmed the earlier findings in [8] and demonstrated that homogeneous particle ignition always occurs in the downstream wake region behind the particle regardless of gas composition. Tufano et al [13,14] performed fully-resolved simulations of coal particle arrays in both laminar and turbulent flows. Vascellari et al [11] modelled the fully-resolved data of [9] with a flamelet approach, in both a priori and a posteriori simulations.…”

“…The experimental trends of ignition delay times in various N 2 /O 2 /CO 2 mixtures were captured and the sensitivity of absolute ignition delay time predictions to gas phase chemistry, particle Reynolds number Re p , particle preheat and extraction criteria for ignition delay were highlighted. The sensitivity of the simulation results to transient effects and varying inter-particle distance (or global equivalence ratios) was studied in [13]. The flamelet table was based on unsteady laminar diffusion flamelets and a novel theoretical formulation of the scalar dissipation rate in the vicinity of single particles allowed for accurate flamelet predictions of the ignition process.…”

“…The flamelet table was based on unsteady laminar diffusion flamelets and a novel theoretical formulation of the scalar dissipation rate in the vicinity of single particles allowed for accurate flamelet predictions of the ignition process. Tufano et al [13,14] performed fully-resolved simulations of coal particle arrays in both laminar and turbulent flows. The sensitivity of the simulation results to transient effects and varying inter-particle distance (or global equivalence ratios) was studied in [13].…”

“…Tufano et al [13,14] performed fully-resolved simulations of coal particle arrays in both laminar and turbulent flows. The sensitivity of the simulation results to transient effects and varying inter-particle distance (or global equivalence ratios) was studied in [13]. A wide range of burning conditions was observed, spanning from individual particle burning (for large spacing/lean mixtures) to group combustion (for small spacing/rich mixtures).…”