Abstract
Measurements were performed in a 300-MWe wall-fired pulverized-coal utility boiler. Enhanced ignition-dual register (EI-DR) burners and centrally fuel rich (CFR) swirl coal combustion burners were installed in the bottom row of the furnace during experiments. Local mean concentrations of O2, CO, CO2 and NO x gas species, gas temperatures, and char burnout were determined in the region of the two types of burners. For centrally fuel rich swirl coal combustion burners, local mean CO concentrations, gas temperatures and the temperature gradient are higher and mean concentrations of O2 and NO x along the jet flow direction in the burner region are lower than for the enhanced ignition-dual register burners. Moreover, the mean O2 concentration is higher and the gas temperature and mean CO concentration are lower in the side wall region. For centrally fuel rich swirl coal combustion burners in the bottom row, the combustion efficiency of the boiler increases from 96.73% to 97.09%, and NO x emission decreases from 411.5 to 355 ppm @ 6% O2 compared to enhanced ignition-dual register burners and the boiler operates stably at 110 MWe without auxiliary fuel oil.
We thank M. Costa and J. L. T. Azevedo for the support to this work. This work was supported by Hi-Tech Research and Development Program of China (Contract No. 2007AA05Z301), the Ministry of Education of China via the 2004 New Century Excellent Talents in University (Contract No. NECT-04-0328), Heilongjiang Province via 2005 Key Projects (Contract No. GC05A314), Key Project of the National Eleventh-Five Year Research Program of China (Contract No. 2006BAA01B01), the National Basic Research Program of China (Contract No. 2006CB200303), and the Post-doctoral Foundation of Heilongjiang Province LRB07-216.