Flowrate distribution of the flue gas system in the boiler and resistance features was derived through a systematic study on the aerodynamic feature in the flue gas tunnel based on the FLUENT numeric simulation with the flue gas system of the 1 000 MW power generation unit as the object in this paper. According to the obtained data

the configuration of the flue gas tunnel and the coal powder pipes system have been optimized aiming at decreasing the pressure in the flue gas tunnel and minimizing amount of work of the project so to make sure a compact structure and accurate selection of the draught fan.