在碳达峰、碳中和背景下,发展燃煤与生物质耦合发电是加快电力转型升级、实现煤电低碳发展的重要途径之一.在某台300 MW循环流化床(CFB)锅炉上设计建设了 一套燃煤直燃耦合生物质的燃烧发电系统,并利用该系统进行了燃煤直燃耦合生物质的燃烧特性试验研究.结果表明:该生物质直燃耦合系统运行稳定可靠;CFB锅炉在掺烧木屑颗粒燃料时,随着掺烧比的增加,混合燃料的飞灰含碳量下降、CO排放量降低,混合燃料的燃尽性得以改善;掺烧后经过锅炉燃烧配风优化,锅炉NOx排放量比纯烧原煤排放量略有降低.试验典型工况污染物测试表明:掺入木屑颗粒燃料后,锅炉烟气二噁英排放量为0.008 8 ngTEQ/m3(标准工况,φ(O2)=11％,下同),飞灰中二噁英排放量为0.020 6 ng TEQ/m3;飞灰中重金属及P、As、Se等有害微量元素排放值总量为32.121 mg/L;底渣中重金属及P、As、Se等有害微量元素排放值总量为3.918 mg/L,烟气和飞灰中的二噁英和重金属等有害物质排放均满足国家环保标准排放限值.
Experimental study on combustion and pollutants emission characteristics of coal coupled with biomass in 300 MW CFB boiler
In the context of carbon peak and carbon neutrality,the development of coal-biomass coupling power generation is one of the important ways to accelerate the transformation and upgrading of electric power and realize low-carbon development of coal power.A coal-fired power generation system directly coupled with biomass combustion was designed for a 300 MW circulating fluidized bed(CFB)boiler,and the combustion characteristics of directly firing biomass with coal were studied by using the system.The results show that,this biomass direct combustion coupling system could run stably and reliably.When wood pellets was co-fired in the CFB boiler,with the increase of wood pellets'blending ratio,the fly ash carbon content of the mixed fuel decreased,the CO emission reduced,and the burnout performance of the mixed fuel improved.After optimization on the boiler combustion and air distribution,the NOx emission was slightly lower than that of pure coal burning.The pollutants test under typical conditions showed that,after adding wood pellets,the dioxin emission from boiler flue gas was 0.008 8 ng TEQ/m3(standard condition,φ(O2)=11％),and the dioxin emission in fly ash was 0.020 6 ng TEQ/m3.The total emission of heavy metals and harmful trace elements such P,As and Se from fly ash was 32.121 mg/l,and that from the bottom slag was 3.918 mg/L.The emission of harmful substances like dioxins and heavy metals in flue gas and fly ash all met the emission limits of national environmental protection standards.
circulating fluidized bed boilerNOxbiomass direct-fired coupling systemcombustion testcontaminant
万方数据
维普
