Principle and Implementation of Fly Ash Recirculation by Bottom-feeding on a Circulating Fluidized Bed boiler Co-burning Coal Sludge and Coal: to Improve Combustion Efficiency and Reduce Pollutions
Coal sludge is a by-product of coal washing, whose production is huge.Burning it in Circulating Fluidized Bed (CFB) boiler can both recover the heat and reduce the pollution.However, the combustion performances of CFB boilers burning coal sludge are generally not high because the particle size is small and residence time is short.For the purpose of improving combustion efficiency and reducing pollutions, fly ash recirculation by bottom-feeding (FARBF) technology was applied to a 75t/h CFB boiler burning mixture of coal sludge and coal.Industrial experiments were carried out to investigate the influence of FARBF technology on combustion performance and pollutant emission characteristics of the boiler.Results show that with FARBF, the dense bed temperature drops while the furnace exit temperature increases, the temperature distribution in the furnace becomes uniform.Under the condition of 100% maximum continuous rate (MCR), the combustion efficiency increases from 92% to 95% and the desulfurization efficiency increases from 83% to 90% as the fly ash recirculation rate increases from 0 t/h to 8 t/h.As the recirculation rate increases, the emissions of NO and CO decrease, but the particulate matter emission increases.The present study indicates that FARBF technology can improve the combustion performance and reduce pollution emissions (except for particulate matter emission) for CFB boilers burning coal sludge, and it can bring significant economical and environmental benefits.
Circulating Fluidized Bed (CFB) Fly ash Recirculation by Bottom-Feeding (FARBF) Combustion Efficiency Desulfurization Efficiency Pollutant emissions
Lunbo Duan Daoyin Liu Xiaoping Chen Changsui Zhao
School of Energy and Environment, Southeast University, Nanjing, 210096, China
国际会议
Proceeding of 2nd Conference of Circulating Fluidized Bed Boiler ( 第二届国际循环流化床锅炉会议)
青岛
英文
161-166
2019-07-19（万方平台首次上网日期，不代表论文的发表时间）