基于回流区特性对水泥回转窑减排NO_x的分析

Analysis of NO_x Emission Reduction Based on Recirculation Region for Cement Kiln

本文提出基于回流区特性实现NOx的减排,并运用FLUENT软件对某2500 t/d线用四通道煤粉燃烧器回流区进行了冷态模拟,研究了燃烧器不同风道的风量变化对回流区的影响,并根据模拟结果进行了调整。结果表明:回流区面积及烟气回流量与内旋流风风量大小成正相关,而轴流风和外旋流风单独改变对回流区特性影响很小;增加内旋流风风量可显著降低烟室NO含量,NO降低约53%;证实了烟气回流的增加可减少回转窑内NOx生成量的推论。

Based on the study of recirculation region in this paper, a method of NOx emission reduction is introduced. A cold-state numerical simulation about the recireulation region, which belongs to a kind of coal burner with 4-channel for a cement production line with capacity of 2500 ton per day, is done by using fluent technology. At last, the influences on recirculation region caused by the airflow distribution changes of 4-channel is researched, and then some experiments are carried out. The results show that the area of recirculation region and the quantity of reflux of flue gas are proportional to the quantity of inner swirling, but axial flow or outer swirling which changes alone has little influence on recirculation region. NO emission reduction is reduced by 53% and the inference that reflux of flue gas can reduce NOx emission reduction is confirmed.