氨逃逸在线监测在火电厂超低排放中的应用

Application of ammonia escape on-line monitoring in ultra-low emission of thermal power plant

"十三五"期间,火电厂超低排放改造正在提速扩围,SCR脱硝是保证烟气中NO_x达标排放的重要举措。合理控制喷氨量能够确保火电厂安全、环保和经济脱硝。氨逃逸的在线监测是指导合理控制喷氨的关键手段。介绍了一种基于可调谐二极管激光吸收光谱技术(TDLAS)的氨逃逸在线监测系统,对其进行实验室测试和现场应用。结果表明,氨逃逸在线监测系统准测量确度在±0.2μL/L以内,零点漂移和量程漂移均在±2.0%F.S./24 h以内,氨逃逸和脱硝出口NO_x浓度变化趋势吻合。

Low-emission transformation of thermal power plants is speeding up the expansion in "the 13th five period".SCR denitrification is an important measure to ensure the emission of NOx in flue gas.Spray ammonia is reasonable controlled to ensure the safety,environmental protection and economic denitrification of thermal power plant.Ammonia escaping on-line monitoring is a key means of guiding rational control of spray ammonia.In this paper,we introduce the ammonia escape online monitoring system based on Tunable Diode Laser Absorption Spectroscopy（TDLAS）.The system is respectively for laboratory testing and field applications.The results show that the system has high accuracy within ± 0.2 μL/L.At the same time,both zero drift and range drift were within ± 2.0% F.S./24 h.It has a good response to the amount of ammonia spray and the change in NOx emissions.