循环流化床锅炉燃煤耦合污泥技术研究与展望  

Research and prospect of coal-fired and sludge-coupled technologies in CFB boilers

作　　者：张自丽 ZHANG Zili(Fujian Boiler&Pressure Vessel Inspection and Research Institute,Fuzhou 350008,China)

机构地区：[1]福建省锅炉压力容器检验研究院,福建福州350008

出　　处：《热力发电》2020年第5期7-13,共7页Thermal Power Generation

基　　金：中央引导地方科技发展专项(2019L3020);福建省科学技术厅自然科学基金项目(2018J05076);国家市场监督管理总局科技计划项目(2019MK035)。

摘　　要：循环流化床(CFB)锅炉燃料适应性广,可实现炉内脱硫,是燃煤耦合污泥技术工业化应用的最佳炉型之一。本文从燃烧工况、污染物控制与排放、数值模拟等方面对CFB锅炉燃煤耦合污泥进行了综述研究。现有研究和工业应用实例表明:将机械脱水污泥经尾部烟气余热或低品位蒸汽炉外干燥后,与煤、生物质、垃圾等混合燃烧,是较为推荐的掺烧方法;针对不同种类、不同来源的污泥,掺烧比例不宜大于30%;炉膛床温最佳控制温度约900℃,这有助于减缓CFB锅炉高温结渣;一般情况下,掺烧污泥对于SO2和NOx排放的影响有限;针对污泥掺烧过程中的二噁英问题,可从燃料源头和燃烧中、燃烧后角度采取控制措施;烟气中重金属排放随着污泥掺烧量的增加而明显增加,因此飞灰需进一步处置后方可再利用。总体而言,CFB锅炉燃煤耦合污泥技术既能回收能源又能最大程度地减量化,具有广阔的发展和应用前景,采用现有污染物脱除设备可实现燃煤耦合污泥污染物达标排放,但相关的CFB锅炉整体数值模型尚未出现或有待完善。Circulating fluidized bed(CFB)boiler has wide adaptability of fuels and can realize desulphurization in furnace,which is considered as one of the best boiler types for industrial co-combustion application of coal and sludge.From the aspects of co-combustion conditions,pollutant emission and control,and numerical simulation,the co-combustion of coal and sludge in CFB boilers is reviewed in this paper.The existing researches and industrial applications show that,the mechanical dewatered sludge being dried by the waste heat of flue gas or the low-grade steam of furnace could be mixed with coal,biomass and garbage for combustion,which was considered as the recommended method for co-combustion of sludge.For different types and sources of sludge,the sludge blending ratio could not be larger than 30%.The optimum bed temperature of furnace could be controlled at about 900℃,which would be beneficial for slowing down the high temperature slagging of CFB boiler.In general,the influence of co-combustion of sludge on SO2 and NOx emissions was limit.For the dioxin problem in the process of cocombustion of sludge,the control measures could be taken from the perspectives of fuel source,combustion and post-combustion.The emission of heavy metals from flue gas increased significantly with the mixed ratio of sludge,so the fly ash should not be reused only after further disposal.In brief,the co-combustion of coal and sludge in CFB boilers can not only recover the sludge energy,but also reduce the sludge quantification to the maximum extent,which has broad development and application prospects.The pollutants’emission standard can be satisfied with the existing pollutant removal equipments.Nonetheless,the relevant overall numerical models of CFB boilers have not appeared and should be improved in the future.

关 键 词：循环流化床锅炉 污泥 水分 灰分 掺烧比例 污染物 数值模拟 

分 类 号：TK6[动力工程及工程热物理—生物能]