Modeling flame propagation of coal char particles in heterogeneous media

Mehdi Bidabadi, Moein Mohammadi, Shafagh M Bidokhti, Alireza K Poorfar, Saeedreza Zadsirjan, Massoud Shariati

Periodica Polytechnica Chemical Engineering

60 (2), 2016, 85-92, 10.3311/PPch.7891

In the present research, combustion of a quiescent coal char particle cloud has been studied in the media with spatially discrete sources by means of numerical approach. A thermal model based on diffusion-controlled regime of coal char particles has been generated in order to estimate the characteristics of flame propagation in heterogeneous media. The model uses discrete heat sources to analyze dust combustion of particles with the diameter of 50 μm. Oxygen and Nitrogen have been considered as the main oxidizer and the inert gas, respectively. Flame propagation speed in various dust and oxygen concentrations has been studied. Flame speed as a function of particle size has been investigated and comparison between cases with and without consideration of radiation effect has been made. Furthermore, minimum ignition energy as a function of dust concentration for different particle sizes has been studied. Results show a reasonable compatibility with the existing experimental data.