Research on Radiation Spectrum of Pulverized Coal Combustion Flame

In order to study on radiation spectrum of pulverized coal flame, radiation spectrums of pulverized coal flame on flat flame burner were measured with fiber optic spectrometer and the radiation characteristic was analyzed in detail. Distribution curves of radiation intensity of flame with wavelength were obtained based on Planck' s Law and calibration by using blackbody furnace. Then, combustion parameters such as temperature and emissivity were calculated by using least square method. Therefore, the measurement method based on radiation spectrum of pulverized coal flame was proposed. And the experimental investigations on pulverized coal flame under different conditions were carried out with this method. The result shows that the radiation spectrum of pulverized coal flame is significant and continuous in the wavelength ranging from 200 to 1 100 nm. The temperature and emissivity of flame can be determined by using Planck' s Law and least square method. Meanwhile, emission peaks of alkali metal such as sodium and potassium appear on the radiation spectrum of pulverized coal combustion flame near 590, 766, 769 and 779 nm, and the appearance of these emission lines is related with temperature. When the concentration of pulverized coal is increasing, the temperature of pulverized coal flame has a little change but the emissivity changes obviously. The intensity of radiation is increasing greatly with emissivity. It can provide important reference for combustion optimization of boiler.