SCR脱硝系统氨管道堵塞原因分析及对策

Reason Analysis and Countermeasure on Ammonia Pipeline Jam of SCR Denitration System

某600MW机组脱硝系统在运行中发生锅炉侧脱硝系统供氨流量下降、供氨压力下降、脱硝出口氮氧化物含量上升的异常现象,主要原因是采用碳钢管做为供氨管道,导致铁的氧化物杂质堵塞了供氨系统阀门门芯,而冬季过低的环境温度影响了氨气流量是杂质在门芯等位置积存的诱因,通过更换氨管道材质并对供氨管道加强保温解决了异常现象,保证了脱硝的正常运行。

A certain 600MW generating set denitration system takes place abnormity phenomena, such as decline of fluxand pressure of ammonia supply from denitration system of boiler side, and ascent of nitrogen oxides content at exit of denitrationin its operation. The main reason is to take carbon steel tube as ammonia supply tube so as to cause oxidation impurity ofiron to stop the valve core of ammonia supply system. The lower temperature in winter affect the ammonia air flow which causesto happen impurity deposit in the valve core. By replacing the materials of ammonia tube and by taking heat preservation andresolving the abnormity phenomena in ammonia supply tube, the normal operation of denitration is ensured.