燃用易结焦煤锅炉空气分级燃烧试验研究

Experimental Study of Air-staged Combustion on a Burning Coking Coal Boiler

为降低NOx排放,对480 t/h燃用易结焦煤种锅炉采用加装分离燃尽风(SOFA)与燃料浓淡燃烧器结合技术进行燃烧系统改造试验,研究了分离燃尽风风门开度、位置、摆角及开启层数对煤粉燃尽率与NOx排放的影响。结果表明:SOFA风门55%开度与开启两层SOFA风门时,锅炉NOx排放浓度均可降低到250 mg/Nm3以下,较改造前的550 mg/Nm3降低约55%,减排效果明显;增大燃尽风摆角可小幅降低飞灰含碳量与减小炉膛出口烟温偏差,但NOx排放明显增加。

In order to reduce NOx emission, an experimental investigation was carried out on a 480 t/h burning easy coking coal boiler, with a technique combini% separated over firing air （SOFA） nozzles above the highest secondary air nozzles and fuel-staged combustion burners in the primary combustion zone. The influence of SOFA damper opening, position, swing angle and opening layer number on the carbon content of fly ash and NOx emission of boiler is investigated. The tests indicate the amount of NOx emission concentration can be decreased to less than 250 mg/ms, reduced by 55% when the SOFA ratio is 55% or open two layers of SOFA. The carbon content of fly ash and the deviation of flue gas temperature at furnace outlet can reduce slightly after the swing angle of SOFA increase, while NOx emission increases obviously.