燃煤机组掺烧城市污泥发电的干化工艺对比  

Comparison of Drying Processes of Coal-fired Generating Units Mixed with Municipal Sludge

作　　者：颜莹莹 黄荣敏 王保龙 郭科赶 黄盛鹏 刘向磊 成浩科 陈雨柔 YAN Ying-ying;HUANG Rong-min;WANG Bao-long;GUO Ke-gan;HUANG Sheng-peng;LIU Xiang-lei;CHENG Hao-ke;CHEN Yu-rou(Yangtze Ecology and Environment Co.Ltd.,Wuhan 430014,China;Lu'an Three Gorges Smart Water Management Co.Ltd.,Lu'an 237005,China)

机构地区：[1]长江生态环保集团有限公司,湖北武汉430014 [2]六安市三峡智慧水管家有限责任公司,安徽六安237005

出　　处：《中国给水排水》2023年第24期53-58,共6页China Water & Wastewater

基　　金：国家重点研发计划项目(2020YFC1908700)。

摘　　要：在政策的驱动下,近年来利用火电厂协同处置污泥的项目逐渐增多,污泥火电厂协同焚烧已经成为国内污泥处置的重要方式之一。污水处理厂外运的湿污泥含水率一般为80%,低位热值仅为100~200 kJ/kg,如果直接送入电厂燃煤锅炉燃烧,将使炉膛温度降低,锅炉效率大幅下降,影响锅炉正常燃烧,因此将湿污泥干化至40%含水率以下,提高污泥热值后进行掺烧是比较合理的掺烧方式。目前,燃煤电厂掺烧污泥的干化方式主要有烟气直接干化法、蒸汽间接干化法和低温带式直接干化法。其中,烟气直接干化法的投资和运行成本较低,但污泥掺烧比例不能太高,否则需抽取的烟气量较大,可能对锅炉热力系统产生影响,造成汽温不足。因此,该工艺的选取需要结合机组热力计算综合确定。蒸汽间接干化法的系统较为复杂,投资和运行成本较高,但对锅炉运行影响较小,可以布置较大规模的污泥干化掺烧系统。低温余热干化法的投资成本较高,运行成本较低,对系统的排烟量和排烟温度的依赖程度较高,污泥掺烧比例不能太高,因此,该工艺的选取也需要结合机组热力计算综合确定。Driven by policies,in recent years,the use of thermal power plants for sludge co-processing has gradually increased.Co-incineration of sludge in thermal power plants has become one of the important methods of domestic sludge disposal.The moisture content of the wet sludge transported by sewage treatment plants is generally about 80%,and its low calorific value is only 100-200 kJ/kg.If the wet sludge is directly sent to the coal-fired boiler of the power plant for combustion,it will reduce the furnace temperature and the boiler efficiency,and affect the normal combustion of the boiler.Therefore,it is more reasonable to dry the wet sludge to water content below 40%to improve the calorific value of the sludge before co-incineration.At present,the drying methods of mixed-combustion sludge in coal-fired power plants mainly include direct flue gas drying,indirect steam drying,and low-temperature belt direct drying.Among them,the investment and operation cost of the direct flue gas drying method is low,but the sludge blending ratio should be controlled.Otherwise,a large amount of flue gas needs to be extracted,which may affect the boiler thermal system,leading to an insufficient steam temperature.Therefore,the selection of the process needs to be comprehensively determined by combining the thermal calculation of the unit.The system of the indirect steam drying method is complicated with high investment and operation costs,but it has little influence on the operation of the boiler.A larger scale sludge drying and co-burning system can be set up.The low-temperature waste heat drying method has higher investment costs,lower operating costs,and a higher degree of dependence on the exhaust volume and temperature of the system,and the proportion of sludge blending should not be too high.Therefore,the process selection also needs to be combined with the thermal calculation of the unit.

关 键 词：污泥电厂掺烧 直接干化 间接干化 污泥处置 

分 类 号：TU992[建筑科学—市政工程]