A group combustion model was developed to investigate the ignition and flame propagation of a dust cloud containing coal particles. The model includes detailed submodels accounting for devolatilization, homogeneous gas phase combustion, heterogeneous char reaction, and radiative heat transfer. Ignition delay time and flame structure at various time steps were presented for a coal-air flame. The gas temperature profile has two peaks during the transient process. The first temperature peak is resulted from fast devolatilization and gas phase combustion. The second peak is results from both the gas phase combustion and char reaction. Increased oxygen concentration shortens the ignition delay time and increases both the gas and particle temperature. Replacing N{sub}2 with CO{sub}2 in the oxidizer decreases flame temperature.
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