超临界和超超临界锅炉煤粉燃烧新技术分析

分析了我国超临界和超超临界锅炉采用的新型煤粉燃烧技术。其主要特点体现在采用了不同的综合性技术构思实现煤粉着火初期低氧燃烧和采用多级配风及NOx还原技术实现低污染排放;在燃烧器内采用煤粉浓缩技术和在喷口附近加强热烟气回流以实现快速着火和低负荷不投油稳定燃烧;采用小功率燃烧器和均衡的火焰温度以降低水冷壁的热负荷,采用旋流式燃烧器对冲布置或直流式燃烧器反向双切圆辐射对流互补的方法减小热偏差;适当增加炉膛容积和设置燃烬风,进一步提高炉内脱氮效果和燃烧效率等方面。

Analysis of New Pulverized Coal Combustion Technology of Super Critical Pressure Boiler

This article analyzes the new type pulverized coal combustion technology adopted in the indigenous supercritical pressure boiler.The main features are:to adopt different comprehensive technological conceptions to realize low oxygen combustion in the imitial stage ignition,to adopt multistage air distribution and NO_x reduction technology to realize low pollution emission,to strengthen hot gas back flow in the vicinity of exhaust nozzle of burners to realize quick ignition and steady combustion at low load without oilaid fiving,to adopt low power burners and equilibrium flame temperature to decrease the thermal load of watercooled wall,to adopt whirl burnersopposed arrangement or impellerless burnersback bitangential radiationcontraflow complement to reduce thermal deflection,and to appropriately increase furnace volume and arrange burnout air to further raise furnace deNO_x effect and improve combustion efficiency etc.