Numerical investigation of the effects of volatile matter composition and chemical reaction mechanism on pulverized coal combustion characteristics

Volatile matter is generally treated as postulated substance or a combination of different species because the detailed chemical compounds in volatile matter are not yet completely understood. However, very few studies investigate the effects of volatile matter composition and chemical reaction mechanism on the pulverized coal combustion characteristics. In this work, numerical simulations of pulverized coal laminar flames stabilized in a two-dimensional counterflow are conducted to examine these effects on the behaviors of pulverized coal combustion. The results show that the pulverized coal combustion characteristics can be changed considerably by slightly varying the species compositions in volatile matter. The pulverized coal flame structure calculated with large hydrocarbon volatile matter can be largely reproduced by a specific combination of light species. It is also shown that the pulverized coal flame structure cannot be correctly predicted by a single-step mechanism. Finally, it is found that both the stable thermo-chemical quantities and some intermediate species (e.g. OH) mass fractions are not sensitive to the choice of chemical reaction mechanism when detailed chemistry is considered.