论文部分内容阅读
The gas-solid flow field is a significant factor for pulverizedcoal combustion.The offset angle of mid-secondray air nozzles strongly affect the gas-solid flow field and the coal combustion performance,especially slagging and pollutant formation.To optimize the offset angles of mid-secondary air nozzles in a tangentially fired furnace,PDA(Particle Dynamics Anemometer)measurement was carried out in a cold model of a 600MW boiler.The results show that the furnace fullness is better,the ignition performance can be improved and a beneficial air-surrounding-fuel (ASF) air-particle flow field can be achieved with the increase of mid-secondray offset angle.Appropriately increasing mid-secondray horizontal offset angle delays the mixing of the secondary air into the primary-air and enhances staged combustion andpromotes an oxidation atmosphere near the water-wall.It is concluded that 18°is competitive to achieve low Nox combustion and avoid slagging.