半焦燃烧及煤热解燃烧耦合试验研究

Experimental study on semi-coke combustion and coal pyrolysis and combustion coupling

为了考察冷半焦、预热半焦及煤热解燃烧耦合所产半焦在循环流化床中的流态化特性和输运特性、燃烧特性及污染物原始排放特性,在循环流化床热解燃烧耦合试验台上进行了冷半焦燃烧、预热半焦燃烧及煤热解燃烧耦合试验研究。研究结果表明,3种类型半焦在燃烧炉炉膛内的流态化特性较好,0~4 mm的预热半焦和粒径0~4 mm煤热解所产半焦均能顺畅通过热解炉与燃烧炉之间的输运通道进入燃烧炉;半焦燃烧时能在燃烧炉炉膛内形成上下均匀的温度场,且随一次风率增大,温度分布更均匀;3种类型半焦的燃烬特性较好,燃烧效率都在99.68%以上;随燃烧炉温度升高,N2O排放值减少,NOx和SO2排放值增加,随二次风比例增大,NOx的排放值降低,SO2排放值升高,N2O的排放值变化不明显。

In order to investigate the characteristics of fluidization,transportation,combustion and original emission of pollutant gas of cold semi-coke,preheated semi-coke and semi-coke produced by coupling combustion with pyrolysis of coal,experiments were carried out in a circulated fluidized bed( CFB) combustor designed with a coupling combustion with pyrolysis system. The results show that three types of semi-coke can be fluidized well in the combustion furnace.Preheated semi-coke with particle size from 0 to 4 mm and semi-coke produced by coupling combustion with pyrolysis of coal with particle size of 0 to 4 mm can smoothly go through the channel between the pyrolysis and combustion furnace. Uniform temperature field is reached during the combustion of semi-coke and it becomes more uniform as the primary air rate increases. The combustion efficiency is 99. 68% higher in all cases,indicating that the burnout characteristics of three types of semi-coke are good. With the increase of the combustion temperature,the emission of N2 O decreases while the emission of NOxand SO2 increases. With the increase of proportion of secondary air,the emission of NOxdecreases,the emission of SO2 increases while the emission of N2 O emissions does not change significantly.