燃烧管长度对煤粉火焰传播规律的影响

Influence of Combustion Tube Length on Propagation Law of Pulverized Coal Flame

为评价煤粉爆炸的危险性,掌握煤粉爆炸过程中火焰传播的规律,实验采用垂直的哈特曼管,选择褐煤为研究对象,研究燃烧管长度对煤粉火焰传播的影响,并使用高速摄影机记录火焰的传播过程.结果表明:随着燃烧管长度的增加,煤粉火焰在传播过程中逐渐变细,同时煤粉火焰前锋阵面的最大高度、火焰传播的最大速度不断增加.火焰传播速度整体呈现先增大后减小的趋势.当燃烧管的长度分别为300 mm、600 mm、750 mm和900 mm时,煤粉云的火焰前锋阵面的最大高度分别达到649 mm、808 mm、1003 mm和1010 mm,煤粉云的火焰传播的最大速度分别为5.4 m/s、12.09 m/s、15.0 m/s和18.61 m/s.研究结果可以为保证煤炭的安全开采提供理论支撑.

To obtain the law of flame propagation and evaluate the hazard in coal dust explosion,lignite was selected to study the effect of the combustion tube length on the flame propagation of coal dust explosion using a vertical Hartmann tube.A high-speed camera was used to record the flame propagation process.The results show that with the increase of the combustion tube length,the combustion flame gradually slenderized,and the maximum height of the flame front and the maximum velocity continuously increased.The flame propagation velocity increased first and then decreased.When the length of the combustion tube was 300 mm,600 mm,750 mm and 900 mm,the maximum height of the flame front reached 649 mm,808 mm,1003 mm and 1010 mm,respectively,and the maximum flame propagation velocity of the pulverized coal cloud was 5.4 m/s,12.09 m/s,15.0 m/s and 18.61 m/s,respectively.The research results can provide theoretical support for ensuring the safe mining of coal.