全负荷脱硝技术在超临界燃煤机组的应用

Application of Full Load Denitration Technology in Supercritical Coal-fired Unit

在低负荷阶段,广东珠海金湾发电有限公司(以下简称"金湾电厂")两台锅炉的脱硝系统因烟温低而退出运行,造成烟气污染物的超标排放。为了使低负荷时氮氧化物(NO_x)的排放达到最新环保要求,金湾电厂对锅炉进行了脱硝改造:首先在锅炉尾部烟道加装了脱硝装置并对省煤器进行分级改造,然后进行低氮燃烧调整以及启停机运行的优化。改造后,烟囱出口NO_x的质量浓度小于30mg/m^3(标准状态下),40%~60%负荷阶段脱硝装置投运率100%,有效地减少污染物的排放,较好地解决锅炉因烟温低而脱硝系统不能投入运行的问题。

In the stage of low load,denitration systems of two boilers in Guangdong Zhuhai Jinwan power generation co.,ltd.（hereinafter referred as Jinwan power plant）was out of service due to low gas temperature which caused discharge beyond standards of flue gas pollutants.In order to ensure emission of NOx satisfy the newest environmental protection requirement at the time of low load,Jinwan power plant conducted denitration transformation for the boiler which was firstly to add denitration device for the tail flue of boiler and carry out classification transformation for the economizer,then make adjustment for low nitrogen combustion and optimization on start and stop of the unit.After transformation,per hour average material quality concentration of NOx at the exit of chimney is less than30 mg/m^3 in standard condition and operational percentage of denitration device in 40%-60%load stage reaches to 100% which effectively reduces emission of pollutants and well solves the problem of the denitration system being unable to be put into operation for reason of low gas temperature.