Pilot plant assessment of blend properties and their impact on critical power plant components

摘要

A series of tests were performed to determine the effects of blending eastern bituminous coals with western subbituminous coals on utility boiler operation. Relative to the baseline bituminous coal, the testing reported here indicated that there were significant impacts to boiler performance due to the blending of the eastern and western coals. Results indicated that fuel blending can be used to adequately control flue gas emissions of both SO(sub 2) and NO(sub x) at the expense of reduced milling efficiency, increased sootblowing in the high-temperature and low-temperature regions of the boiler and, to a lesser extent, decreased collection efficiency for an electrostatic precipitator. The higher reactivity of the subbituminous coal increased the overall combustion efficiency, which may tend to decrease the impact of milling efficiency losses. The extent of these impacts was directly related to the percentage of subbituminous coal in the blends. At the lowest blend ratios of subbituminous coal, the impacts were greatly reduced.