燃煤耦合污泥焚烧发电技术研究进展  

Research progress of coal-fired coupled sludge incineration power generation technology

作　　者：王飞[1] 张盛 王丽花 WANG Fei;ZHANG Sheng;WANG Lihua(College of Energy Engineering,Zhejiang University,Hangzhou 310027,China;Shanghai Chengtou Wastewater Treatment Co.,Ltd.,Shanghai 201203,China)

机构地区：[1]浙江大学能源工程学院,浙江杭州310027 [2]上海城投污水处理有限公司,上海201203

出　　处：《洁净煤技术》2022年第3期82-94,共13页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2019YFC1907000);国家自然科学基金资助项目(51976188);浙江省科技计划资助项目(2021C03162,2022C03092);宁波市科技创新2025重大专项资助项目(2018B10023)。

摘　　要：焚烧法作为实现我国污泥快速减量化、无害化处置的主流方式得到广泛应用,而在“双碳”减排目标的推动下,燃煤耦合污泥焚烧发电技术能有效实现燃煤低碳减排和污泥清洁焚烧处置。然而,现阶段燃煤耦合污泥焚烧发电技术在锅炉结焦结渣、燃烧污染物排放和技术经济性等方面仍存在较多问题。总结了污泥基本理化性质、水分赋存形态、煤质指标和不同干化技术,对比分析了湿污泥直接掺烧、烟气直接干化污泥后掺烧和饱和蒸气间接干化污泥后掺烧这3种技术路线的优缺点,并结合我国燃煤耦合污泥发电典型工程项目的技术参数进行深入分析。实践表明,湿污泥直接掺烧存在燃烧工况稳定性差、处置量低等问题,而“干化+掺烧”技术路线能在保证燃烧热稳定性的基础上实现较大的污泥处置量。考虑到烟气直接干化污泥存在粉尘爆炸风险高、烟气量需求大等问题,利用饱和蒸气间接干化污泥后掺烧燃烧效果较好。在污泥间接干化技术中,桨叶式干化和圆盘式干化热效率高、粉尘产生量低、占地面积小。由于污泥干化过程中存在黏滞性,需选取合适的干化模型对传热传质过程进行分析。我国燃煤耦合污泥发电典型工程项目运行实践表明,污泥掺烧比例控制在较佳范围时,既能保证燃煤机组燃烧热效率,又能满足常规污染物、重金属和二噁英等污染物的排放标准。在国家政策层面,亟需对燃煤耦合污泥焚烧发电技术污染物排放标准、发电补贴标准和碳减排核算标准等相关政策加以明确和细化,大力推动该技术的发展。Incineration is widely used as the mainstream way to achieve the rapid reduction and harmless disposal of sludge in China,and with the aim of"double carbon"emission reduction plan,co-combustion of sludge with coal can realize the carbon emission reduction and the clean incineration of sludge.However,there are still many problems in slagging,combustion pollutant emission and technical economy.The basic physical and chemical characteristics,water content distribution,coal quality index,and drying technologies of sludge were ana⁃lyzed.The advantages and disadvantages of three technical routes of co-combustion of sludge with coal,i.e.,direct co-combustion,co-combustion of sludge dried directly by flue gas,and co-combustion of sludge dried indirectly by steam,were thoroughly analyzed based on the typical co-combustion projects.The results show that direct co-combustion of wet sludge is faced with poor combustion stability and low disposal capacity,and the combination of drying and co-combustion can achieve a large disposal capacity and ensure the combustion stability.Considering the problems of high dust explosion risk and large demand for flue gas in the direct drying of sludge by flue gas,co-combustion of sludge dried indirectly by steam is a better choice with good combustion performance.Among sludge indirect-drying technologies,paddle drying and rotary disc drying have high thermal efficiency,low dust production,and small floor area.Due to the existence of viscosity during sludge drying,it is necessary to select an appropriate drying model to analyze the heat and mass transfer process.Based on the operation practice of typical co-combustion projects in China,it is found that when the blending ratio of sludge is well con⁃trolled,co-combustion technology can not only ensure high combustion thermal efficiency,but also meet the emission standards of pollu⁃tants including conventional pollutants,heavy metals and dioxins.In terms of national policy,it is urgent to clarify and refine corresponding policies,e.g.,the

关 键 词：燃煤机组 污泥 掺烧 燃煤耦合 干化技术 燃煤污染物 

分 类 号：TQ426[化学工程]