固体回收燃料掺烧对污泥燃烧特性的影响

Influence of the added solid recovered fuel on the combustion characteristicsof sewage sludge

为了掌握固体回收燃料(Solid Recovered Fuel,SRF)掺烧对污泥焚烧处置的热反应特性及烟气环境特性的影响,通过使用德国耐驰公司生产的热综合分析仪、SEM、XRD和GA-21plus烟气分析仪着重解析了不同掺烧比例时SRF与污泥混燃过程的热重规律、综合燃尽特征指数、结渣特性和烟气中NO_(x)排放特性。结果表明:混烧过程存在明显的多峰失重现象,主要集中在192.3~645.3℃;SRF掺烧提高了燃料的失重速率,掺混比11%时,最大失重速率达0.14%/min,显著高于污泥单独焚烧的失重速率。随着SRF掺烧比提高,燃料的着火温度和燃尽温度降低,充分燃烧阶段向低温区域偏移。SRF掺混比为11%时,稳定燃烧性能指数和综合燃烧性能指数分别提升了1.38倍和1.17倍,改善了污泥单独焚烧时的着火特性。另外,SRF掺混后燃料灰熔融温度升高,灰分黏附程度降低,颗粒聚团强度降低,从而减弱了污泥单独焚烧时结渣情况,然而掺混燃烧导致烟气中NO_(x)排放量增加。

In order to understand the effects of Solid Recovered Fuel(SRF)blending on the thermal reaction characteristics and flue gas environmental characteristics of sludge incineration disposal.The thermogravimetric law,comprehensive burning characteristic index,slagging characteristic and NO_(x)emission characteristic of SRF and sludge mixed combustion process under different mixing ratio were analyzed by using thermal synthesis analyzer,SEM,XRD and GA-21plus flue gas analyzer.The results show that there are obvious multi-peak weight loss phenomena in the mixed firing process,mainly concentrated at 192.3-645.3℃.At 11%blending ratio,the maximum weight loss rate reaches 0.14%/min,which is significantly higher than that of sludge incineration alone.With the increase of SRF blending ratio,the ignition temperature and burnout temperature of the fuel decrease,and the full combustion stage shifts to the low temperature region.When the SRF mixing ratio is 11%,the stable combustion performance index and comprehensive combustion performance index are increased by 1.38 times and 1.17 times,respectively,which improves the ignition characteristics of sludge incineration alone.In addition,after SRF mixing,the melting temperature of fuel ash increases,the adhesion degree of ash decreases,and the agglomeration strength of particles decreases,thus weakening the slagging situation when the sludge is incinerated alone.However,the mixed combustion leads to an increase in NO_(x)emission in the flue gas.