摘要
针对600 MW超临界W火焰锅炉,通过数值模拟的方法研究了煤粉浓度和燃烬风对劣质无烟煤燃烧NOx释放特性的影响。结果表明,NOx主要在煤粉燃烧前期距一次风喷口2～4 m处大量生成,选择合适的煤粉浓度,炉内NOx最大值可下降16.5%;与常规浓度相比,高浓度煤粉燃烧可有效降低炉膛出口NOx排放;燃烬风对炉内各物质含量及NOx的生成影响显著,燃烬风率由6%增加到15%,炉膛出口NOx排放量由756.0 mg/m3下降到502.9 mg/m3。
In light of a 600 MW supercritical pressure W-flame boiler, the NOx release characteristics during the com- bustion of poor-quality anthracite were numerically simulated at the conditions of different pulverized coal concentra- tions and different over-fire air rates. The results indicate that a large quantity of NOx is generated in the initial burning stage of pulverized coal, at the distance of 2 - 4 m away from the primary air nozzles. The maximum of NOx in the fur- nace can be reduced by 16.5% by choosing a reasonable pulverized coal concentration. Compared with the conven- tional concentration, NOx emissions at furnace exit can be effectively reduced during the combustion of pulverized coal with higher concentration. Over-fire air has great effects on the substance contents and the generation of NOx in the fur- nace, NOx emissions at furnace exit decrease from 756. 0 mg/m3 to 502.9 mg/m3 with the rate of over-fire air increas- ing from 6% to 15%.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2012年第2期310-315,共6页
Journal of China Coal Society
基金
国家自然科学基金资助项目(50906030)
关键词
超临界W火焰锅炉
NOx释放
煤粉浓度
燃烬风
数值模拟
supercritical pressure W-flame boiler
NOx emissions
pulverized coal concentration
over-fire air
numeri-cal simulation
