CFD prediction of physical field for multi-air channel pulverized coal burner in rotary kiln

来源期刊：中南大学学报(英文版)2006年第1期

论文作者：马爱纯 周孑民 欧俭平 李旺兴

文章页码：75 - 79

Key words：CFD; numerical simulation; CFX; physical field; multi-air channel coal burner; rotary kiln

Abstract: A 3-D numerical simulation with CFX software on physical field of multi-air channel coal burner in rotary kiln was carried out. The effects of various operational and structural parameters on flame feature and temperature distribution were investigated. A thermal measurement was conducted on a rotary kiln (4.5 m in diameter, 90 m in length) with four-air channel coal burner to determine the boundary conditions and to verify the simulation results.The calculation result shows that the distribution of velocity near burner exit is saddle-like; recirculation zones near nozzle and wall are useful for mixture primary air with coal and high temperature fume. A little central airflow can avoid coal backing up and cool nozzle. Adjusting the ratio of internal airflow to outer airflow is an effective and major means to regulate flame and temperature distribution in sintering region. Large whirlcone angle can intensify disturbution range at flame root to accelerate ignition and mixture. Large coal size can reduce high temperature region and result in coal combusting insufficiently. Too much combustion air will lengthen flame and increase heat loss.