Numerical Study of Pulverized Coal Ignition Characteristics under O2/CO2 Atmosphere

O-2/CO2 combustion of pulverized coal is one of the promising new technologies in order to reduce the emission of CO2 and NOx from coal combustion furnaces. In this paper, an unsteady-state model of pulverized coal cloud consider the radiation and convection was used, by numerical simulation, a typical bituminous coal ignition characteristics was studied in air and O-2/CO2 atmosphere and also carried out experiment study, experiment results are in good agreement with the calculated results. Results shows that when the atmosphere changed from air to O-2/CO2, ignition delay time and ignition temperature both increased, the range of temperature increase is about 1020K. With the increase of coal concentration the ignition delay time and ignition temperature reduced under O-2/CO2 atmosphere, the ignition delay time is reduced when the ambient temperature is increased, and the ambient temperature has a greater impact on ignition delay time under O-2/CO2 atmosphere, leading a longer ignition delay time.