锅炉燃烧调整对NOx排放和锅炉效率影响的试验研究

在2台典型的1025 t/h锅炉上进行了燃烧调整降低NOx排放浓度的试验研究,通过改变过量空气系数、辅助风配风方式、运行负荷和制粉系统运行方式等,测定了锅炉尾部烟道NOx排放浓度,分析了锅炉运行工况、运行方式对NOx排放的影响.结果表明:降低过量空气系数,烟煤锅炉NOx减排效果比贫煤锅炉好得多;降低负荷,烟煤锅炉的NOx排放量降低值较大;缩腰式配风的NOx排放浓度比均匀配风方式约降低10%,制粉系统的运行方式影响炉内燃料的燃烧状态和温度分布,也影响NOx的生成和排放.在不降低锅炉效率的前提下,调整燃烧工况,可降低锅炉排放NOx浓度1O%～20%.

Experimental Study of the Effect of Boiler Combustion Control on NOx Emission and Boiler Efficiency

The influences of boiler combustion control on NO. emission have been studied on two typical 1025 t/h boilers. By changing the excessive air coefficients, the amounts of burnout air, boiler loads, milling system operational modes, and so on, the influences of boiler operating conditions and modes on NOx emission have been analyzed. The results show that the with the decrease of the excessive air coefficient and boiler load, NOx emission of the bituminous coal fired boiler reduces much more than that of the lean coal fired boiler. And the NO. emission of the constricted air distribution mode is 10% lower than that of the uniform mode. The operational mode of milling system influences coal combustion and temperature profile in the furnace as well as the NOx emission. The NO. emission can be reduced by 10-20% through combustion control without reduction of boiler efficiency.