锅炉SCR烟气脱硝空气预热器堵塞原因及其解决措施

AIR PREHEATER BLOCKING IN BOILER WITH SCR DENITRIFICATION DEVICE:REASON ANALYSIS AND SOLUTIONS

分析锅炉进行SCR烟气脱硝时空气预热器冷段元件硫酸氢氨堵塞的原因,认为其主要因SCR装置过量喷氨或局部过量喷氨造成大量氨逃逸所致。对此,提出对于运行效果较差的空气预热器,可结合降低排烟温度或者漏风率进行其换热元件的综合改造等措施。同时,建议空气预热器冷段换热元件在煤中硫含量较低以及出口综合温度较高时采用高性能的考登钢材质。

Heat transfer elements of preheater on boiler with SCR denitrification equipment were blocked by ammonium bisulfate(ABS).Large amount of ammonia escaping caused by excessive ammonia injection in SCR equipment or it's local area was considered as the main reason.Thus,comprehensive retrofit for heat transfer elements of preheater with bad operation effect should be conducted,combining with decreasing the exhaust gas temperature or air leakage rate.Meanwhile,the heat transfer element for cold segment of air preheater should be made of Corten steel,for the low sulfur content coal,or high outlet integrated temperature.