石化污泥与煤流化床混烧NO_x的排放特性

在一座热输入量为0.2MW的循环流化床试验台上进行了石化污泥与煤的混烧试验,重点考察了质量掺混比、空气过剩系数、二次风率、Ca/S摩尔比、床温等因素对NOx排放浓度的影响。试验结果表明,随着质量掺混比的增大,NOx的排放浓度呈下降趋势;随着空气过剩系数的增加,NOx的排放浓度呈上升趋势;在空气过剩系数保持不变的条件下,随着二次风率的增加,NOx的排放浓度下降;脱硫剂石灰石的添加会促进NOx的生成,且NOx的排放浓度随着Ca/S摩尔比的增大而显著上升;随着床层温度的升高,NOx的排放浓度也呈增加趋势。由于循环流化床低温和分级燃烧对NOx的抑制作用,各试验工况NOx排放浓度均较低,满足国家排放标准。

NOx Emission Characteristics during Co-combustion of Petrochemical Sludge and Coal in Fluidized Bed

The tests of co-combustion of petrochemical sludge and coal were conducted in a 0.2 MW circulating fluidized bed (CFB) test facility focusing on the influences of mass mixing ratio, excess air coefficient, the secondary air fraction, Ca/S molar ratio, bed temperature on NOx emission characteristics. The investigations show that NOx concentration in flue gas decreases with the increase of mass mixing ratio of sludge or the secondary air fraction. The NOx emission increases with the increase of excess air coefficient or bed temperature. The addition of limestone can facilitate the formation of NOx and the NOx emission increases rapidly with the increase of Ca/S molar ratio. During the test runs, NOx concentration in flue gas is quite low and meets the national standard for NOx emission due to the suppression effect of low temperature and staged combustion in the CFB.