污泥与煤流化床混燃特性  

Co-combustion characteristics of sludge and coal in fluidized beds

作　　者：高远[1] 王卫群[1] 黄治军[1] 段元强 段伦博 GAO Yuan;WANG Weiqun;HUANG Zhijun;DUAN Yuanqiang;DUAN Lunbo(Jiangsu Frontier Electric Technology Co.,Ltd.,Nanjing 211100,China;Key Laboratory of Energy Thermal Conversion and Control under Ministry of Education,School of Energy and Environment,Southeast University,Nanjing 210096,China)

机构地区：[1]江苏方天电力技术有限公司,江苏南京211100 [2]东南大学能源与环境学院能源热转换及其过程测控教育部重点实验室,江苏南京210096

出　　处：《煤炭学报》2024年第10期4080-4087,共8页Journal of China Coal Society

基　　金：江苏方天电力技术有限公司科技资助项目(KJ202212);江苏省碳达峰碳中和科技创新专项资金(重大科技成果转化)资助项目(BA2022202);江苏省自然科学青年基金资助项目(BK20210238)。

摘　　要：污泥与煤混燃能够有效改善燃料的着火和燃烧特性,实现污泥的无害化与资源化利用。市政污水在消毒和脱水过程中引入的氯元素会增加市政污泥中氯的质量分数,进而对锅炉换热面和环保设备产生不利影响。利用热重-傅里叶红外分析仪和鼓泡流化床反应器,考察了不同操作条件对燃料着火、氯元素析出、灰粒径和元素分布的影响规律。结果表明,污泥中的挥发分较高,在其微商热重曲线中有3个失重峰,且最大失重峰出现在挥发分析出和燃烧阶段。随着污泥掺烧比例增加,燃料的着火温度和燃尽温度降低;烟气中CO、NO和SO_(2)的体积分数随着污泥掺烧比例的增加而增加,污泥中较高的挥发分促进了CO的生成,同时减弱了密相区的还原性气氛,不利于NO的还原;燃烧过程中,无论是热重还是流化床实验均表明燃料中85%以上的氯元素都以HCl形式析出,且灰对HCl的自捕集作用较弱,燃料中绝大多数氯元素最终都以气态HCl形式进行排放;飞灰的平均粒径随着污泥掺烧比例的增加而减小;随着污泥掺烧比例的增加,飞灰中钾、磷和铁的质量分数显著上升,尤其是磷元素的增幅最为明显。Co-combustion of sludge with coal can effectively improve the ignition and combustion characteristics and promote the harmless and resourceful utilization of sludge.Inorganic or organic chlorine can be introduced into municipal sewage during the disinfection and dehydration.The increased chlorine content in municipal sludge may adversely affect boiler heat exchange surfaces and environmental protection equipment.The influence of operating parameters on ignition,Cl element release,particle size,and element distribution of fly ash was investigated using a thermogravimetric-Fourier Transform Infrared Analyzer and a laboratory-scale bubbling fluidized bed.The results show that the volatile content in the sludge is high,and there are three weight loss peaks in its derivative thermogravimetric(DTG)curves,and the maximum weight loss peak appears in the volatile release and combustion stage.As the sludge blending ratio increases,the ignition and burnout temperatures of the fuel gradually decrease.The emission concentrations of CO,NO and SO_(2)increase as the sludge blending ratio increases.The higher volatile content in the sludge promotes the production of CO,while weakening the reducing atmosphere in the dense phase,which is not conducive to the reduction of NO.During the combustion process,both thermo-gravimetric and fluidized bed experiments show that more than 85% of the chlorine elements in the fuel are released in form of HCl,and the self-trapping effect of ash on HCl is weak,and most of the Cl elements in the fuel eventually are emitted in the form of gaseous HCl.The average particle size of fly ash gradually decreases as the sludge blending ratio increases,indicating that sludge ash breaks into finer particles at high temperatures.As the sludge blending ratio increases,the contents of K,P,and Fe elements in fly ash increase significantly,with P showing the most notable increase.

关 键 词：污泥 掺烧 污染物 HCl析出特性 流化床 

分 类 号：TK16[动力工程及工程热物理—热能工程]