水泥窑炉窑尾烟气NOx碳热还原数值模拟研究  

Numerical Simulation on Carbothermal Reduction of NOx in Flue Gas From Cement Kiln

作　　者：王晓伟 蔡军[1,2] 任强强 陈锐[1,2] WANG Xiaowei;CAI Jun;REN Qiangqiang;CHEN Rui(Institute of Engineering Thermophysics,Chinese Academy of Sciences,Haidian District,Beijing 100190,China;University of Chinese Academy of Sciences,Shijingshan District,Beijing 100049,China)

机构地区：[1]中国科学院工程热物理研究所,北京市海淀区区100190 [2]中国科学院大学,北京市石景山区100049

出　　处：《中国电机工程学报》2023年第3期1060-1071,共12页Proceedings of the CSEE

基　　金：中国科学院A类战略性先导科技专项(XDA21040300);中国科学院青年创新促进会优秀会员项目(2012129)。

摘　　要：烟气碳热还原是减少燃煤水泥窑炉NO_(x)排放的有效方法,围绕该方法在水泥窑炉领域的实际应用,该文以宁夏某水泥公司的2500t/d水泥窑炉生产线为研究对象,采用计算流体力学(computational fluid dynamics,CFD)方法对水泥窑炉窑尾烟气NO_(x)碳热还原进行数值模拟。系统探究水泥窑炉C5出口烟气初始O_(2)含量、烟气初始温度以及给煤速率等因素对烟气碳热还原效果的影响规律。模拟结果表明:随着烟气初始O_(2)含量降低,NO_(x)还原效率逐渐升高,但是换热效率变差;烟气初始温度在1023.15~1123.15K范围内时,随着烟气初始温度升高,NO_(x)还原效率先降低后升高;随着给煤速率增加,NO_(x)还原效率逐渐升高。综合考虑,烟气初始O_(2)含量以控制在1%左右为宜,而烟气初始温度为1048.15K时较为理想,综合考虑烟气/生料的温升与NO_(x)还原效果,给煤速率控制在700kg/h比较合适。该文研究结果可为烟气碳热还原技术在水泥窑炉的实际应用提供一定理论指导和参考。Carbothermal reduction of NO_(x)in flue gas is an effective method to reduce NO_(x)emissions from coal-fired cement kilns.Focusing on the practical application of this method in the field of cement kilns,the 2500t/d cement kiln production line of a cement company in Ningxia is taken as the research object,and the computational fluid dynamics(CFD)method is used to conduct numerical simulation research on carbothermal reduction of NO_(x)in flue gas.The influences of initial O_(2)contents in flue gas at C5 outlet,initial temperatures in flue gas at C5 outlet and coal feeding rates on carbothermal reduction effect of flue gas are explored.The simulation results show that with the decrease of the initial O_(2)content in flue gas,the reduction efficiency of NO_(x)gradually increases,but the heat exchange efficiency becomes worse.When the initial flue gas temperature is in the range of 1023.15~1123.15K,the NO_(x)reduction efficiency decreases first and then increases with the increase of the initial flue gas temperature.With the increase of coal feeding rate,the NO_(x)reduction efficiency gradually increases.Overall,the initial O_(2)content of flue gas should be controlled at about 1%,and the initial temperature of flue gas at 1048.15K is suitable.Considering the temperature rise of flue gas and raw material and NO_(x)reduction effect,the coal feeding rate should be controlled at 700kg/h.The results of this study can provide important theoretical guidance and reference for the practical application of flue gas carbothermal reduction technology in cement kilns.

关 键 词：水泥窑炉 脱硝 碳热还原 数值模拟 

分 类 号：TK16[动力工程及工程热物理—热能工程]