摘要
针对带燃烧器的分解炉建立模型并进行燃烧与分解耦合及NO_(x)转化的数值模拟。其中,采用多表面反应模型来计算焦炭的燃烧过程,深入剖析煤粉燃烧机理,通过自定义反应速率考虑CO_(2)分压对生料分解的影响,通过分析CO与NO的交互关系研究NO_(x)的转化情况,模拟结果与工程数据取得合理一致性。结果表明:燃烧器的存在使得煤粉大量集中在壁面附近,并沿壁面进行燃烧,极易对分解炉壁面造成损伤。煤粉燃烬率很高,其主燃烧区位于2.53—7.73 m内。生料入炉后,在9.04 m高度处迅速分解,最终分解率为91.7%,由于生料的初始分解位置高于煤粉主燃区的位置,煤粉燃烧与生料分解整体耦合性较差,炉内存在2处明显的局部高温。来自分级煤管的煤粉燃烧产生大量CO,有效地还原来自烟室的NO,还原率达到57.5%。
Numerical simulations were conducted to investigate the interplay of combustion and decomposition and the associated NO_(x) conversion within a precalciner with burners.A multiple surface reactions model was used to char burning,with a particular focus on the mechanisms governing the combustion of pulverized coal.CO_(2) partial pressure′s impact on raw meal decomposition was considered by customizing the reaction rate.The conversion of NO_(x) was studied by analyzing CO and NO interaction.Simulation results were in reasonable agreement with engineering data.The results indicate that the presence of the burners makes pulverized coal near the wall and combustion along it,which is likely to damage precalciner wall.Notably,pulverized coal exhibits a high burnout rate,and the main combustion zone is located in the range of 2.53-7.73 m.The raw meal is decomposed rapidly at the height of 9.04 m after entering into the precalciner,with a final decomposition rate of 91.7%.Due to the initial decomposition site of the raw meal is higher than that of the main combustion zone of pulverized coal,pulverized coal combustion and the decomposition of the raw material is poorly coupled on the whole,and there are two obvious local high temperature zones in the precalciner.Furthermore,the combustion of pulverized coal from the graded coal pipe yields a substantial amount of CO,effectively reducing NO from the flue gas chamber,with a reduction rate of 57.5%.
作者
刘勇
谢峻林
梅书霞
刘长江
李全亮
LIU Yong;XIE Junlin;MEI Shuxia;LIU Changjiang;LI Quanliang(School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,Hubei Province,China;Department of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;Guangxi Free Trade Zone Jianju Technology Co.,Ltd.,Qinzhou 535000,Guangxi,China)
出处
《化学工程》
CAS
CSCD
北大核心
2024年第9期61-66,共6页
Chemical Engineering(China)
关键词
分解炉
焦炭燃烧
碳酸钙分解
NO_(x)转化
数值模拟
precalciner
char burning
calcium carbonate decomposition
NO_(x)conversion
numerical simulation
作者简介
刘勇(1999-),男,硕士,研究方向为CFD数值模拟,电话:18260638307,E-mail:18260638307@163.com;通信联系人:梅书霞,女,博士,高级实验师,E-mail:msx0303@163.com。
