Assessment of pulverised coal and secondary fuel mixtures combustion using image processing

Abstract

Air stepping, which takes place in pulverised-coal burners, makes combustion less stable. Such a situation may lead to shifting the flame, unstable combustion and eventually to extinguishing of the flame. Adding secondary fuels such as waste fuels and biomass spoils combustion stability and leads to increasing corrosion and boiler slagging. Spatial distribution of radiation intensity (flame shape) and its changes in time domain deliver the quickest and straight information of combustion process itself. We have utilised flame images taken by CCD camera in a several combustion tests to find flame shape features, which would point a state of unstable combustion.