煤泥在一台600 MW W火焰锅炉上的掺烧试验与数值模拟

Experimental and Numerical Investigation of a 600 MW W-flame Boiler Co-firing Anthracite and Coal Slime

以某600 MW W火焰锅炉为例,开展了无烟煤掺烧煤泥的热重实验、燃烧数值模拟和现场掺烧试验研究,分析了掺烧煤泥对着火、燃烧和NO_x排放特性以及运行经济性的影响。结果表明:掺烧煤泥可以改善无烟煤的着火特性,但其综合燃烧特性会变差;掺烧煤泥时,炉内温度降低,固体未完全燃烧损失增加,锅炉效率和NO_x质量浓度也会降低;当煤泥的掺混比例小于10%时,对锅炉稳定燃烧和运行不会产生显著影响,但可以减少发电成本;当煤泥掺混比例大于10%时,通过提高风粉比和减小颗粒粒径等优化方式可以改善炉内燃烧状况,降低飞灰含碳质量分数,但NO_x的质量浓度会有一定程度的上升。

Taking a 600 MW W-flame boiler as an example,thermogravimetric analysis,numerical simulation and field tests were conducted on the combustion characteristics of various anthracite-coal slime mixtures,so as to analyze the ignition,combustion and NOx emission characteristics as well as the operation efficiency of the boiler under co-firing conditions.Results show that the ignition characteristics of anthracite could be improved by blending in coal slime,but the comprehensive combustion characteristics would get worse.Under co-firing conditions,the in-furnace temperature reduces,the solid incomplete combustion loss increases,and the boiler efficiency decreases,but the mass concentration of NOx drops.When the blending ratio of coal slime is less than 10%,the power generation cost could be reduced without significant influence on the stable combustion and operation of the boiler.When the blending ratio gets above 10%,the combustion condition could be improved and the carbon content in fly ash could be reduced by increasing the ratio of air to pulverized coal and by reducing the particle size,however,the mass concentration of NOx would be increased in this case.