某电厂脱硝系统氨逃逸故障分析与处理

Analysis and Treatment of Ammonia Escape in Denitrification System of a Power Plant

针对脱硝系统出口氨逃逸质量浓度过高导致空气预热器腐蚀、堵塞以及二次污染等问题,以某电厂氨逃逸故障为例,对烟气温度、NOx质量浓度、氨逃逸情况、运行数据等进行分析,认为入口氨氮摩尔比分布不均以及部分区域氨量过喷是造成脱硝出口氨逃逸超标的主要原因,提出降低入口NOx质量浓度的同时减少NOx质量浓度波动幅度、调整脱硝反应器入口氨氮摩尔比分布、评估催化剂性能等措施避免脱硝系统氨逃逸现象。

The high escape concentration of ammonia from the denitration system can lead to corrosion,blockage and secondary pollution of the air preheater.Taking the ammonia escape fault of a power plant as an example,the flue gas temperature,NOx mass concentration,ammonia escape situation and operation data were analyzed.The results show that the uneven distribution of molar ratio of ammonia nitrogen and the overinjection of ammonia in some areas are the main reasons for the excessive ammonia escape.The ammonia escape phenomenon in the denitration system can be avoided by reducing the mass concentration of NOx at the entrance and the fluctuation of the NOx mass concentration at the same time,adjusting the mole concentration distribution of ammonia and nitrogen at the inlet of denitration reactor,evaluating catalyst performance,etc.