Abstract The transient whole-coupling model in a spherical coordinate system on single pulverized coal pyrolysis and combustion was developed, taking into consideration various pyrolysis product release, heat transfer, mass transfer, and chemical reactions. The igntion and combustion characteristics of Shenmu bituminous coal were simulated. The result shows that the ignition of pulverized coal begins from volatiles, and the volatile flame can move rapidly to a position departing from the center of the coal particle by about 29 times radius, due to the limitation of oxygen diffusion; when the coal pyrolysis is completed, the CO generated by surface oxidation reaction has been ignited, the flame returns almost to the coke particle surface, the particle temperature rises abruptly, and the coke combustion is controlled by the surface oxidation reaction; with the combustion rate increasing, the coke combustion begins to be controlled by the surface reducing reaction, and the char flame departs from the particle surface again.
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