Numerical simulation of influence factors on mineral matter vaporization during pulverized coal combustion

Based on the currently available test devices and measuring methods, it is quit difficult to accurately measure the vaporization rate of mineral matter in coal combustion process. A mathematic model was developed to predict the vaporization rate of mineral matter in this paper. The effect of CO2 partial pressure, temperature and size of coal particles on the vaporization rate of mineral matter was considered in the model. The vaporization behavior of the mineral matter in a 600 MWe coal-fired utility boiler furnace was simulated. The results showed that the coal particle temperature is a main factor affecting the mineral matter vaporization, while the coal particle size and CO2 partial pressure also have an effect on vaporization. The mineral matter vaporization occurred primarily along the particle trajectories after a short time when the particle temperature reached 1800 K. The comparison of the simulation results with experimental data showed that the modeling results are in good accordance with the laboratory measurements