燃煤烟气降温过程汞的均相化学反应动力学模拟  

KINETICS MODELING OF HOMOGENOUS MERCURY TRANSFORMATION IN COAL-DERIVED FLUE GAS COOLING PROCESS

作　　者：陈雷[1] 姚强[1] 禚玉群[1] 赵香龙[1] 

机构地区：[1]清华大学热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2007年第2期343-346,共4页Journal of Engineering Thermophysics

基　　金：国家重点基础研究发展规划项目资助(No.2002CB211606;No.2006CB200300)

摘　　要：本文建立了燃煤烟气冷却过程中汞氧化的均相反应动力学模型,使用化学动力学软件Chemkin4．0．1,通过理论计算考察各种影响汞均相氧化的因素,并对实验电厂的烟气汞氧化过程进行模拟,与实验结果进行对比．模型显示600 K左右为典型燃煤烟气氧化速率最快的温度区间；煤中氯含量近线性增加汞的氧化；烟气中汞的氧化受到动力学控制,因而低的烟气降温速率有利于汞的氧化．对电厂烟气的模拟显示,600 K左右的空气预热器是汞氧化速率最快的区域；而在400 K左右的除尘器中因停留时间长,汞也得到了明显的氧化。均相化学反应动力学模型对电厂汞排放模拟的结果与实验显示了一定的吻合,但模型对大部分电厂汞的氧化预测结果均比实验值偏高,需要进一步完善．A kinetics model for homogeneous mercury transformation in coal-derived flue gas was established with Chemkin 4.0.1, to investigate the factors affecting mercury transformation, and simulate the power plant flue gas cooling process. The model shows that the temperature range for highest oxidation rate is about 600 K in typical flue gas, chlorine increases mercury oxidation rate linearly, and lower cooling rates lead to more oxidation because of kinetic-controlled reactions. The simulation results of power plant flue gas cooling process show that mercury is oxidized promptly in Air Preheater for proper temperature range, and also oxidized much in Particulate Control Devices for long residence time. The simulation results coincide with onsite tests in some ways, however they over-predicted most of the cases, indicating further improvements are need in the future.

关 键 词：汞 煤燃烧 动力学 污染控制 

分 类 号：TQ534[化学工程—煤化学工程]