水泥分解炉和预热器内NO_(x)形成与脱除过程的数值模拟  

Numerical simulation of NO_(x) formation and removal process in cement preheater and calciner

作　　者：唐小春 宋华庭 Tang Xiaochun;Song Huating(Guangxi Yufeng Group Co.,Ltd..,Liuzhou,545000,China;不详)

机构地区：[1]广西鱼峰集团有限公司,广西柳州545000 [2]中国中材国际工程股份有限公司(南京),江苏南京211100

出　　处：《水泥工程》2025年第1期1-7,18,共8页Cement Engineering

摘　　要：为应对水泥行业超低排放要求,需不断优化改善分解炉自脱硝和选择性非催化还原(Selective Non-Catalytic Reduction,SNCR)的脱硝效率。本文以分解炉和C6预热器为对象,采用计算颗粒流体力学(Computational Particle Fluid Dynamics,CPFD)数值模拟方法对窑尾NO_(x)的形成、自脱硝和SNCR脱硝进行了分析。研究了燃料为烟煤和无烟煤时,分解炉内NO_(x)的形成和自脱硝过程,对比了在不同位置喷氨时,窑尾SNCR的脱硝效果。结果显示无烟煤中氮主要以焦炭氮的形式存在,焦炭氮随着焦炭的缓慢燃烧逐步形成NO_(x),而烟煤中的挥发分氮在分解炉锥部转换成NO_(x)后即可快速被还原,燃烧无烟煤时,分解炉出口NO_(x)排放更高;C6预热器内的强旋流场有助于氨气在烟气中的分散,提升SNCR脱硝效率,在C6喷氨的脱硝效果明显优于在分解炉喷氨,另外,在分解炉和C6同时喷氨的脱硝效果要优于在单独在分解炉或C6喷氨。To meet the ultra-low emission requirements of the cement industry,continuous optimization and improvement of self-denitrification and Selective Non-Catalytic Reduction(SNCR)for higher denitrification efficiency are essential.In this paper,the formation process of NO_(x),self-denitrification process and SNCR denitrification process in calciner and C6 preheater are analyzed by using the Computational Particle Fluid Dynamics(CPFD)numerical simulation method.The NO_(x) formation and self-denitrification process in the calciner are investigated when using bituminous coal and anthracite as fuels.The denitrification efficiencies of SNCR system are compared when ammonia is injected at different locations.The re-sults show that the nitrogen in anthracite mainly exists in the form of Char-N,which gradually forms NOx as the char burns slowly,while the Vol-N in bituminous coal can be rapidly reduced after being converted into NO_(x) in the conical zone of cal-ciner.When anthracite is used as the fuel,the NO_(x) emission at the outlet of calciner is higher than that of bituminous coal.The rigorous swirling flow field inside the C6 preheater is beneficial to the dispersion of ammonia in the flue gas,resulting in improvements in denitrification efficiency of SNCR system.When ammonia is injected in C6 preheater,the denitrifica-tion efficiency is significantly better than in the calciner.Additionally,the denitrification efficiency when injecting ammo-nia in the calciner and C6 preheater at the same time is better than that in the calciner or C6 preheater alone.

关 键 词：分解炉 C6预热器 自脱硝 SNCR脱硝 数值模拟 

分 类 号：TQ172.6[化学工程—水泥工业]