摘要
建立模型研究过量空气系数对锅炉热效率和污染物控制的影响。结果表明,各工况下锅炉热效率最高时,对应不同的最佳过量空气系数。1 000MW超超临界机组负荷从550MW增加到950MW时,最佳过量空气系数从1.18增加到1.35。烟气温度和流量、排烟热损失和炉内对流换热均随过量空气系数增大而增大,锅炉热效率、NOx生成量、炉膛和火焰温度均随过量空气系数先增大后减小。较低负荷下维持一定程度偏大的过量空气系数不仅能提高锅炉热效率,还能增加烟气温度,维持SCR脱硝系统正常投运。
A model was established to study the effect of the excess air coefficient on the boiler thermal efficiency and control of pollutants. The results show that various optimum excess air coefficients correspond to the maximum boiler thermal efficiency for various operating conditions. The optimum excess air coefficient increases from 1.18 at a unit load of 550 MW to 1.35 at 950 MW. The flue gas temperature and flow rate, heat loss from flue gases and convective heat transfer all increase with the excess air coefficient. The boiler thermal efficiency, the amount of NOx, and the furnace and flame temperatures increase then decrease with increasing the excess air coefficient. For very low unit loads, a larger excess air coefficient can be set to increase the boiler thermal efficiency and the flue gas temperature to maintain the normal operation of the SCR denitrification system.
出处
《锅炉技术》
北大核心
2015年第3期30-34,39,共6页
Boiler Technology
关键词
过量空气系数
锅炉热效率
热损失
烟气温度
SCR脱硝系统
excess air coefficient
boiler thermal efficiency
heat loss
flue gas temperature
SCR denitrification system
