Concurrent measurements of temperature and soot concentration of pulverised coal flames

This paper presents a novel instrumentation system for the concurrent measurements of temperature and soot concentration of pulverised coal flames. The system operates on the two-colour principle combining advanced optical sensing and digital image processing techniques. The temperature of a flame is calculated from the ratio between the grey-levels of corresponding pixels within two images captured at two different wavelengths. The soot concentration of the flame is estimated using the KL factor which is derived from the intermediate information obtained during the temperature measurement. The prototype system has been evaluated on a 0.5 MW_th coal-fired furnace. Experimental results obtained show that the system is capable of measuring the instantaneous, two-dimensional distributions of the temperature and soot concentration of the flame with a reasonable accuracy