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.