Combustion experimental analysis into effects of interaction between blended coals on the NO emission

Abstract

Abstract In studies of blended coal combustion, blending methods have an effect on NO emissions, but few experimental studies investigate the coal combustion in different height of furnace. In order to compare the effects of different blending methods on the NO emission during combustion process, bituminous coal, anthracite and their blended coal were burned in various modes in a two-layer and layer distance adjustable reactor. The results showed that NO emission of blended coal decreased nonlinearly with the blending ratio of bituminous coal (BBR) increasing. It indicated that interactions between component coals affected NO formation, leading to different NO emission in these three blending methods (two in-furnace blending methods and one out-furnace blending method). Compared with other methods, the in-furnace blending method (bituminous coal on the upper layer and anthracite on the lower layer) showed a great potential to reduce NO emission. Particularly, when the layer distance increased to 200 mm and the BBR is 70%, the NO emission reached the lowest.