市政污水污泥水热耦合干化系统能耗模拟  

Simulation of energy consumption in municipal sewage sludgehydrothermal coupled drying system

作　　者：冯昱恒 韩梦曦 余天驰 金则陈 胡维杰 张鹏飞 陆利烨 吴乃新[5] FENG Yuheng;HAN Mengxi;YU Tianchi;JIN Zechen;HU Weijie;ZHANG Pengfei;LU Liye;WU Naixin(School of Mechanical and Energy Engineering,Tongji University,Shanghai 201800,China;Neogene Intelligent Technology Co.,Ltd.,Shanghai 200001,China;Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092,China;Huaneng Taicang,Suzhou 215400,China;Shanghai Boiler Factory Co.,Ltd.,Shanghai 200245,China)

机构地区：[1]同济大学机械与能源工程学院,上海201800 [2]上海新近纪智能科技有限公司,上海200001 [3]上海市政工程设计研究总院(集团)有限公司,上海200092 [4]华能太仓电厂,江苏苏州215400 [5]上海锅炉厂有限公司,上海200245

出　　处：《洁净煤技术》2023年第9期69-77,共9页Clean Coal Technology

基　　金：上海市“科技行动计划”国际合作课题资助项目(22230730300,21230731100);上海市“科技创新行动计划”科技支撑碳达峰碳中和专项资助项目(21DZ1209200)。

摘　　要：干化+焚烧技术已逐渐成为我国大中城市中心城区污泥的重要处置手段,水热炭化预处理可提高污泥脱水性能,进而降低系统能耗,但对水热+干化污泥预处置过程的能耗分析还鲜有报道。研究了200~260℃下水热炭化预处理污泥的三相产物分布及水热液有机组分构成,在此基础上建立了水热+空气干化系统的能量-质量流模型,并分析了水热条件对系统能耗的影响,最后与空气干化系统、厌氧发酵+空气干化系统能耗进行对比。发现釜内压力为8 MPa,水热反应温度由200℃上升至240℃时,由于水热液中热值较高的有机组分芳香烃、含氮杂环比例明显下降,水热反应釜能耗由184 kJ/kg(以原污泥计)降至161 kJ/kg,温度上升至260℃时,由于水蒸气气相分率明显增加及水热液中芳香烃含量回升,能耗上升至278 kJ/kg。受水蒸气气相分率影响,240℃下水热反应能耗随压力升高而降低,压力升至4 MPa后降低趋势迅速放缓。直接空气干化系统在干化空气温度为110℃时,系统总能耗为1942 kJ/kg;厌氧消化+干化系统由于对沼气进行高效热回收利用,消化时间为10 d时,系统热耗低至212 kJ/kg,总能耗为984 kJ/kg;而水热炭化+干化系统由于有效提升了污泥脱水性能,使系统总能耗进一步降低,240℃水热温度下系统总能耗为597 kJ/kg。研究结果为污泥独立焚烧或与燃煤电站耦合燃烧前预处理方式的选择和优化提供了基础数据和理论依据。Drying and incineration technology has gradually become an important disposal method for sludge in the central urban areas of large and medium-sized cities in China.Hydrothermal carbonization can improve the dewatering property of sludge,thereby reducing the energy consumption of the system.However,there are few reports on the energy consumption analysis of hydrothermal and drying sludge pre-disposal process.In this article,the distribution of three-phase products and the organic components of hydrothermal liquid at hydrothermal temperatures from 200℃to 260℃were studied.Based on this,the energy-mass flow model of the hydrothermal and air-drying system was established,and the impact of different hydrothermal conditions on system energy consumption was analyzed.Finally,the energy consumption with air-drying system,and the anaerobic fermentation as well as the air drying system was compared.It is found that when the pressure inside the kettle is 8 MPa,the temperature of hydrothermal reaction is increased from 200℃to 240℃.The energy consumption of the hydrothermal reactor decreases from 184 kJ/kg(sludge,the same below)to 161 kJ/kg,mainly due to a significant decrease in the proportions of aromatic hydrocarbons and nitrogen-containing heterocyclic rings in the hydrothermal liquid.When the temperature rises to 260℃,the energy consumption increases to 278 kJ/kg due to the significant increase in the vapor phase fraction and the recovery of aromatic hydrocarbon mass.It is found that the energy consumption of hydrothermal reaction at 240℃decreases with the increase of pressure due to the influence of the vapor phase fraction.The decreasing trend slows down rapidly after the pressure increases to 4 MPa.The total energy consumption of the direct air drying system is 1942 kJ/kg when the drying air temperature is 110℃.In the anaerobic digestion and drying system,due to the efficient heat recovery of biogas,the heat consumption is as low as 212 kJ/kg at 10 days′digestion time,and the total energy consumption is

关 键 词：污水污泥 水热炭化 能耗分析 热干化 预处理 过程模拟 

分 类 号：TK6[动力工程及工程热物理—生物能] TK9