为降低NOx 排放浓度，减轻结焦，对150 MW机组480 t/h 四角切圆燃烧锅炉采用燃料浓淡分级与加装分离燃尽风(SOFA)相结合的技术进行燃烧系统改造，并进行了改造后燃烧优化调整试验.结果表明：SOFA挡板55％开度且开启2层挡板时，锅炉 NOx 排放量均可降至250 mg/m3以下，较改造前的550 mg/m3降低约55％，减排效果明显；燃用五彩湾煤时，锅炉效率可达到92％以上，最优工况下可达到92．48％，较改造前91．69％提高了0．79％；炉膛出口烟温能够控制在850℃以下，有效地减轻了高温受热面结焦，保证锅炉长期经济、安全运行.%In order to reduce the NOx emission and inhibit coking in boiler furnace,transformation was car-ried out on a 480 t/h tangentially fired boiler,by using the technology combining the fuel-staged combus-tion technology with installation of the separated over firing air (SOFA)nozzles above the highest second-ary air nozzles.Moreover,combustion optimization and regulation tests were performed after the retrofit-ting.The results indicate that:the NOx emission decreased to lower than 250 mg/m3 (by 55%)when the SOFA damper opened with two layers and with opening degree of 5 5%;when burning Wucaiwan coal,the boiler had efficiency higher than 92%,and the optimal efficiency reached up to 92.48%,about 0.79% high-er than that before the retrofitting;the exhaust temperature was lower than 850 ℃,which can prevent the boiler from coking on heating surface effectively,and ensure the economy and safety of boiler operation.
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