天然气锅炉NOx及CO排放控制试验研究

为了响应政府业及民用天然气锅炉达到超低氮排放,要求绝大多数天然气锅炉采用低氮燃烧器+烟气再循环系统的技术路线,实施后普遍出现NO_x、CO含量偏高、炉膛振动较大等问题。借助116 MW天然气锅炉进行试验研究,研究了燃烧器燃料配比、燃烧火焰长度、助燃空气氧含量三个因素对NO_x及CO的影响,并对投入烟气再循环前后炉膛振动情况进行了检测。试验表明:燃烧器燃料内外配比对NO_x、CO生成影响较大,两者呈现相反趋势变化;燃烧火焰长度对NO_x生成影响较大,对CO含量影响较小;助燃空气氧含量对NO_x、CO生成以及锅炉振动影响较大。三种影响因素相比,助燃空气氧含量影响更为突出。

Experimental study on NOx and CO emission control of natural gas boiler

In order to satisfy the requirements of ultra-low nitrogen emission from natural gas boilers most natural gas boilers adopt the low nitrogen Burner with flue gas recirculation system.However,problems such as high content of NO_xand CO and large furnace vibration appear.Experiments are carried out on the 116 MW natural gas boiler to investigate the influences of burner fuel ratio,combustion flame length and oxygen content of combustion supporting air on NO_xand CO.And the furnace vibration before and after flue gas recirculation is tested.The experimental results show that:the internal and external ratio of burner fuel has a great influence on NO_xand CO generation,and the two show opposite trend.The length of combustion flame has great influence on NO_xgeneration,but little effect on CO content.The oxygen content of combustion supporting air has a greater impact on NO_x,CO generation and boiler vibration.Analyzing the effects of the three factors,it is found that the influence of oxygen content in combustion air is more prominent.