生物质(气)耦合燃煤锅炉运行性能及污染物分析

Operation Performance and Pollutant Analysis of Biomass(Gas)Coupled Coal-fired Boiler

为了对比分析生物质与燃煤直接燃烧和生物质气耦合燃煤对锅炉运行性能及污染物排放的影响,基于660 MW燃煤锅炉和30 t/h生物质气化炉,搭建生物质气化耦合燃煤锅炉系统模型。在额定工况下,选取松木、木屑、污泥3种生物质,进行气化,对比分析生物质和生物质气与燃煤耦合燃烧2种情况下的锅炉运行性能及燃烧产物的变化规律。结果表明:生物质直接掺烧提高了炉膛燃烧温度和排烟温度,锅炉热效率均低于纯煤燃烧的锅炉热效率。生物质气掺烧降低了炉膛燃烧温度,提高了锅炉热效率。松木气的炉膛燃烧温度降低了45.26℃,木屑气的排烟温度降低了为41.32℃。生物质气掺烧对NO_(x)减排效果更为显著,木屑气掺烧生成的NO_(x)质量浓度最低;生物质直接燃烧对SO_(x)的减排效果更好,松木掺烧生成的SO_(x)质量浓度最低。

In order to compare and analyze the impact of biomass and coal-fired direct combustion and biomass-gas-coupling coal-burning on the operation performance and pollutant emissions of the boiler,a biomass gas was built based on a 660 MW coal-fired boiler and a 30 t/h biomass gasifier Model of chemically coupled coal-fired boiler system.Under rated operating conditions,three types of biomass,pine wood,wood chips,and sludge were selected for gasification,and the boiler operating performance and combustion product change laws under the two conditions of biomass and biomass gas and coal-fired coupled combustion were compared and analyzed.The results show that the direct blending of biomass increases the furnace combustion temperature and exhaust gas temperature,and the thermal efficiency of the boiler is lower than that of the pure coal combustion boiler.The mixed combustion of biomass gas reduces the combustion temperature of the furnace and improves the thermal efficiency of the boiler.The combustion temperature of the pine gas in the furnace is reduced by 45.26℃,and the flue gas temperature of the sawdust gas is reduced to 41.32℃.The mixed combustion of biomass gas has a more significant NO_(x) reduction effect,and the mass concentration of NO_(x) generated by the mixed combustion of wood chips gas is the lowest.The direct combustion of biomass has a better SO_(x) reduction effect,and the mixed combustion of pine has the lowest SO_(x) mass concentration.