Numerical modelling of one-dimensional laminar pulverized coal combustion

摘要

A model for laminar, premixed pulverized-coal flame propagation has been developed which includes particle radiation, conduction between gas and particles, and combustion of volatiles and char. Radiative heat transfer between particles is described by the two-flux model. Both the multiple parallel reaction model (MPRM) and the distributed activation energy model (DAEM) are used for decomposition kinetics, while six sets of multistep reaction models are used for volatiles (CO, HCN, C(sub 2)H(sub 6), CH(sub 4) and H(sub 2)) combustion. The burning of coal char is described by the single-film model and two char oxidation models are used for testing. The composition of volatiles is calculated by the interpolated method. The model is evaluated by comparing predicted particle temperature and composition profiles with experimental data for a flat-flame coal-dust burner. Flame temperatures and heat fluxes were measured by a multi-wavelength infrared pyrometer technique. A new multistep kinetic reaction model, called 'reduced model 3' with 15 reactions, which describes the oxidations of CO, CH(sub 4) and H(sub 2), is proposed. This reduced model gives the best results (particle temperatures and concentrations) compared with experimental data. (au) 98 refs.