水泥三喷腾分解炉煅烧过程数值模拟研究

Numerical simulation study on calcination process of cement triple-spouting precalciner

为了深入研究分解炉内的煅烧过程,提高煅烧效果,运用Fluent软件对国内某水泥公司4 500 t/d TTF分解炉进行了数值建模。在选取Standard k-ε模型、离散相模型和组分传输模型模拟出流场和温度场的基础上,分析了煤粉燃烧过程及生料角度、三次风速度和温度对炉内煅烧过程的影响。结果表明:生料入射角度对分解率有较大的影响;三次风速度较大时,生料分解率和焦炭燃烬率也较高;三次风温度升高,会引起助燃空气不足,降低焦炭反应活性,从而降低燃烬率;通过优化3个参数,CaCO_3分解率达到90.3%,焦炭燃烬率达到88.0%。开展水泥分解炉煅烧过程数值模拟研究并将之应用于实际工程项目中,可为优化水泥生产工况提供理论参考,对水泥工业与资源环境的协调发展具有较大的现实意义。

To study the calcination process in a precalciner and improve calcination effect, the 4 500 t/d TTF precalciner in a domestic cement company is numerically modeled by Fluent. By selecting the standard k-ε model, discrete phase model and component transfer model, the flow field and temperature field are simulated, based on which, the pulverized coal combustion process and the effects of cement raw meal angle, tertiary air velocity and tertiary air temperature on calcination process are analyzed. The results show that the incidence angle of raw meal has great influence on the decomposition rate. When the tertiary air velocity is higher, the decomposition rate of raw meal and the burning rate of coke are also higher. Increase in tertiary air temperature causes insufficient combustion air and reduces coke reactivity, thereby reduces combustion rate. By optimizing the three parameters, the decomposition rate of CaCO3 and the burning rate of coke can reach 90.3% and 88.0%, respectively. The research on the numerical simulation of cement precalciner calcination process and its application in practical engineering projects can provide theoretical reference for optimizing cement production conditions, and has great practical significance for the cement industry and its coordinated development with resources and environment.