摘要
煤粉再燃是降低NOx排放的一项新技术。借助FLUENT6.1软件平台,采用数值模拟方法对一台容量为35 t/h的四角切圆燃烧锅炉改造前后炉内燃烧过程进行研究。改造前为空气分级燃烧,改造后为超细煤粉再燃燃烧。计算结果表明:改造后在最上面一层一次风喷口的高度区域,形成一个相对低温,低氧的还原性气氛区域—再燃区。再燃降低NOx18.8%,并且与改造前的燃尽效果相当。煤粉颗粒在炉内运动具有很大的随机性,停留时间差异很大。平均而言,煤粉喷入位置越高,停留时间也越短。
Coal reburning is a new technique to reduce NOx emission. By the use of CFD software FLUENT 6.1, combustion processes in a 35t/h tangentially fired boiler before reconstruction and after are simulated. Air staging technique is applied before reconstruction and micronized coal reburning after reconstruction. Results show that deoxidization zone is formed at the height of 1.505m in furnace after boiler reconstruction. It can be concluded that micronized coal reburning can reduce NOx emission up to 18.8%, while coal still burns out effectively after reconstruction. Coal particle movements in furnace are random. Averagely, particle residence time is shorter if they are injected from a higher height position.
出处
《锅炉技术》
北大核心
2008年第5期43-48,共6页
Boiler Technology
关键词
热能动力工程
四角切圆燃烧
再燃
改造
数值模拟
thermal power engineering
tangential combustion
reburningreconstruction
numerical simulation
