Air-Blown Conversion of Micronized Coal: Numerical Simulation and Experiment

Influence of coal micronization on air-blown conversion of pulverized coal fuel is under study. On the basis of these experiments, computational fluid dynamics methods are used to perform simulation determining the conditions of the process under study. Conversion of coarse coal in a medium of combustion products of fine coal with the following parameters: a flow rate ratio of primary and secondary coal is 0.82; a corresponding air flow rate is 0.35; the stoichiometric coefficient of primary, secondary, and total air are 0.8, 1.87, and 1.39; temperatures in the active zone are higher than 1200°C. According to the computational results for this regime, the carbon conversion rate for the primary and secondary coal is 100% and 60%, respectively, and its total value is $$\approx$$ 80%. The results obtained suggest that it is possible to increase the efficiency of coal combustion due to micronization technologies as applied to oil-free ignition and torch illumination systems on steam pulverized coal boilers at TPPs.