Abstract
This paper presents the experimental detections of the combustion process in a 300 MW arch-fired boiler burning a low quality coal. Visualizations of two-dimensional (2-D) temperature distribution in the furnace based on a novel flame image processing technique have been carried out. The detections have been the first time to perform on this type of boiler. The average temperature and emissivity of the flame have been calculated along the height. The results indicate that the flame center, which should be generally designed to locate in the lower furnace center, shifts upward close to or into the upper furnace above the arches. It shortens the running distance of the flame in the lower furnace and is unfavorable to the burnout of the pulverized coal. The flame emissivity decreases with the increase of the burnout degree of the pulverized coal along the furnace height.
