Spectroscopic Observation of Chemical Species From High Temperature Air Pulverized Coal Combustion

Abstract

In situ monitoring of chemical species from the combustion pulverized coal in hightemperature air is examined using several different spectroscopic diagnostic at different equivalence ratios. Twodimensional (2D) distributions of flame temperature were obtained using a thermal video camera. The experimental results showed the temperatures to range from low to 1400 آ°C under various conditions of fuellean, stoichiometric, and fuelrich. The highest temperature and flame stability were obtained under fuellean combustion condition. The chemical species generated from within the combustion zone were analyzed from the spontaneous emission spectra of the flame in the Ultraviolet–visible (UVVis) range. The spatial distribution of NO, OH, and CN were identified from the spectra. The 2D distribution of emission intensity visualized and recorded for NO, OH, and CN revealed hightemperatures close to the root of the flame that rapidly dispersed radially outward to provide very high temperatures over a much larger volume at further downstream locations of the flame.