STUDY ON COMBUSTION CHARACTERISTICS OF LIGNITE IN A CFB BOILER
The shortage of coal promotes the lignite utility in power plant because of the rapid economy development recently. However, lignite is high in moisture content as well as volatile content and low in calorific value. It is very difficult to burn in traditional pulverized coal fired boiler. Circulating fluidized bed (CFB) boiler is an alternative with low pollutant emission. Some CFB boilers are built and put into commercial operation in Northeast China and East Inner Mongolia where lignite is abundant. The operation experiences of these boilers are introduced in this paper. The effect of coal particle size on bottom ash ratio, combustion efficiency, thermal efficiency, pollution emission, and ash deposits in convective heating surface were investigated. It was found that for the lignite fired CFB boiler, the largest coal particle size should be 20 to 40mm to maintain bed material balance. But the bottom ash only shares less than 10％ of the total ash. Due to high volatile content in the lignite, the combustion efficiency could achieve more than 99％. Meanwhile, NOx emission was relative low and satisfied national environment protection requirement. It is suggested that flue gas velocity in convective heating surface should be ranged in a certain scope to prevent ash deposit and erosion.
CFB boiler lignite coal particle size performance
J.Leng T.S.Zou J.X.Wu C.Jiang J.L.Gao J.Wu D.Su D.Y.Song
Northeast Electric Power Research Institute Co., Ltd, ShenYang, 110006,China
国际会议
第20届国际流化床燃烧会议(20th International Conference on Fluidized Bed Combustion)
西安
英文
429-433
2009-05-18（万方平台首次上网日期，不代表论文的发表时间）