SCR脱硝系统分区控制式喷氨格栅的优化

安徽芜湖电厂2#炉喷氨格栅采用分区控制式喷射技术。由于格栅阀门开度、浓度场、速度场三者之间耦合较差，导致反应器出口烟道NH3/NOx分布极不均匀，实测NOx最大偏差达74.7 mg·m-3，NH3逃逸率最高达11.4 μL·L-1，下游空气预热器安全运行受到严重影响。基于全区域NH3/NOx等摩尔比理念，并综合考虑该反应器入口的浓度场和速度场状况进行喷氨格栅优化。调整后，在660、500、330 MW3种典型工况下，NOx浓度最大偏差分别降至5.8、10.3、11.8 mg·m-3，NH3逃逸率由调前的4.64 μL·L-1分别降至调后的2.67、3.03、2.14 μL·L-1。系统总效率基本不变，但效率峰谷差异下降明显。

Optimization of partition controlled ammonia-injection grid in SCR denitrification system

The ammonia-injection grid (AIG) of the No. 2 boiler in Anhui Wuhu Power Plant uses partition controlled injection technology. Due to the poor coupling of the valve opening of the AIG in relation to the concentration and velocity conditions,the NH3/NOx concentration distribution of the reactor outlet was extremely uneven. The maximum deviation of measured NOx reached 74.7 mg·m-3,and the highest escape rate of NH3 soared to 11.4 μL·L-1. Therefore, the safe operation of the air pre-heater was severely affected. This study presents the optimization of the AIG system based on the concept of full area equal NH3/NOx molar,and comprehensively considers both the concentration field and velocity field conditions in the reactor. After adjustments,the maximum deviations of NOx concentration were reduced to 5.8,10.3,and 11.8 mg·m-3 under the three typical conditions of 660,500,and 330 MW,respectively. The escape rate of NH3 dropped to 2.67,3.03,and 2.14 μL·L-1 from the previous 4.64 μL·L-1. The total efficiency of the system remains unchanged,but the difference in efficient peaks decreased significantly.