电力学报2025，Vol.40Issue(3)：161-170,10.DOI:10.13357/j.dlxb.2025.018
纯燃气流床煤气化细渣的LFFF-CFB燃烧技术
LFFF-CFB Combustion Technology for Pure Fine Slag from Entrained-flow Gasification
摘要
Abstract
The coal gasification fine slag(GFS)generated during the gasification process in the entrained-flow bed has a relatively high carbon content.All existing resource utilization approaches require a decarbonization treatment process.Meanwhile,the circulating fluidized bed(CFB)combustion technology demonstrates excel-lent fuel adaptability.Nevertheless,it is widely recognized within the industry that the residual carbon during the formation of GSF is encapsulated within the molten vitreous body.As a result,under the CFB combustion temperature(about 900℃)conditions,it is extremely difficult to be completely combusted.In order to explore the feasibility of efficient burnout of entrained-flow gasifier GFS in CFB boilers,this paper has successively in-vestigated the occurrence forms of carbon and ash in the GFS,the carbon reaction activity,and its combustion characteristics under fluidized bed conditions.Through comparative studies of scanning electron microscopy and loss-on-ignition experiments before and after FS grinding,the microscopic morphology of the separation of porous residual carbon particles from ash particles is revealed,and the difference in weight loss of FS before and after grinding is only 2.86%.Furthermore,it is clarified that the residual carbon in GFS mainly exists out-side the molten inorganic substances,namely the"ash-char separation"occurrence form.The TGA and burn-out experiments in the muffle furnace demonstrate that the burnout of GFS could be achieved under the medi-um-temperature combustion conditions of CFB.In view of the characteristics of typical Geldart Group A parti-cles with fine particle size of GFS,the commonly used fluidization wind speed of traditional CFB fails to offer sufficient system residence time,thereby being unable to fulfill the efficient combustion demands of fine-grained GFS.Based on the rapid fluidization map,a Low-gas-velocity Fast Fluidization of Fine Particles(LFFF)CFB combustion technology for pure GFS is proposed.The fluidization velocity Utr is selected to be much lower than the conventional fluidization wind speed and slightly higher than the transition velocity,there-by significantly enhancing the residence time of GFS within the system.A one-dimensional CFB combustion model is utilized to predict and analyze the flow characteristics of GFS at the low fluidization gas velocity and the temperature distribution of the boiler.Finally,a CFB boiler scheme with an annual processing capacity of 240 000 t for the LFFF combustion technology that solely burns fine gasification slag is proposed.关键词
循环流化床/气流床气化细渣/灰炭分离/低气速细粒子快速流态化Key words
circulating fluidized bed(CFB)/fine slag from entrained-flow gasification/ash-char separation/low velocity fine particle fast fluidization(LFFF)分类
能源与动力引用本文复制引用
李雨,周托,王瑀,赵翠晶,杨海瑞,王银峰,张缦..纯燃气流床煤气化细渣的LFFF-CFB燃烧技术[J].电力学报,2025,40(3):161-170,10.基金项目
新疆维吾尔自治区重点研发计划项目(2024B03031). （2024B03031）
