Large eddy simulation of soot formation in a laboratory pulverized coal flame

[Display omitted] •A DS-FPV model is extended to predict the PAHs formation in PCC.•The extended DS-FPV model is coupled with the EQMOM method for soot formation.•Soot volume fraction distribution can be well predicted at the upstream region.•Soot formation/consumption are mainly controlled by surface growth/OH oxidation. In this paper, the dual-scale flamelet/progress variable (DS-FPV) model, which has been validated in gas-phase turbulent combustion, is extended to predict the polycyclic aromatic hydrocarbons (PAHs) formation in pulverized coal combustion. Moreover, the extended DS-FPV model is also coupled with a soot model to predict the soot formation in a turbulent jet flame of pulverized coal. In the soot model, the extended quadrature method of moments (EQMOM) is applied to solve the transport equation of soot number density function, and the sub-processes of nucleation, condensation, surface growth, surface oxidation and aggregation are considered. The results show that the distribution of soot volume fraction can be well predicted at the upstream region, but under-prediction appears at the downstream region, which is caused by the over-prediction of volatile matter release rate. In addition, the formation characteristics of PAHs and soot are analyzed. It is found that PAHs are mainly formed at the stage of volatile matter combustion. The soot formation is mainly controlled by surface growth, and the soot consumption is mainly controlled by OH oxidation.