A technical method to improve NOx/NH3 mixing ratio in SCR system and its engineering applications
A technical method to improve NOx/NH3 mixing ratio in SCR system and its engineering applications
复制标题
DOI：
10.1016/j.joei.2018.12.005
复制
发表时间：
2019-12-01
影响因子：
5.7
通讯作者：
Luo, Kai Hong
中科院分区：
文献类型：
--
作者：
Liu, Guofu;Cui, Yidong;Luo, Kai Hong
为了优化电厂选择性催化还原（SCR）系统NOx/NH3混合比，提出了一种诊断注氨网前截面区域内NOx通量分布的技术方法，用于指导注氨网支管的阀门调整。根据截面面积相应分区的NOx通量分布，可以定量确定AIG系统各支管的权重系数。实现不同AIG支管阀门的控制策略，指导AIG前整个横截面区域内的NH3喷射，提高NOx/NH3混合比。该技术已在某660mw电厂SCR系统烟气隧道的一侧（通常SCR系统的两个隧道称为a侧和b侧）上应用了一年多。SCR系统的氨耗率降低了约12.62%，出口NOx分布均匀性的标准差提高了约79.01%。空气预热器烟气阻力的上升速度比SCR系统的其他烟气隧道慢39.18%。这表明该技术的应用明显抑制了空气预热器上粘性硫酸氢铵（ABS）的形成。(C) 2018能源研究所。Elsevier Ltd.出版。版权所有。
A technical method for diagnosing the distribution of NOx flux within the cross-section area in front of ammonia injection grid (AIG) was proposed for guiding the valve-tuning of AIG branch-pipes, in order to optimize the NOx/NH3 mixing ratio in the selective catalytic reduction (SCR) system of power plant. The weight coefficient of each branch-pipe in AIG system can be quantitatively determined with regard to the distribution of NOx flux in the corresponding sub-zone of the cross-section area. The control strategy of the valves for different AIG branch-pipes can be achieved for guiding the NH3 injection and improving the NOx/NH3 mixing ratio within the whole cross-section area in front of AIG. The technology has been applied on one side of the SCR system flue-gas tunnels (normally two tunnels for the SCR system called as A-side and B-side) of a 660 MW plant for more than one year. The ammonia consumption rate of the SCR system was reduced about 12.62% and the uniformity of outlet NOx distribution was estimated to be greatly improved by about 79.01% with regard to the standard deviation. The rising rate of the flue gas resistance of the air preheater was slown down by 39.18% compared to that of the other flue-gas tunnel of SCR system. This implied that the formation of the sticky ammonium bisulfate (ABS) on air preheater was significantly inhibited through the application of this technology. (C) 2018 Energy Institute. Published by Elsevier Ltd. All rights reserved.