密闭管内甲烷－煤粉复合爆炸火焰传播规律的实验研究

在1.2 m长竖直爆炸管内对不同初始条件下的甲烷－煤粉混合物进行了弱点火火焰传播实验。分别考察了甲烷浓度、煤粉浓度、煤粉粒径以及点火延迟时间对复合爆炸火焰传播特性的影响。结果表明，煤粉的存在使得纯甲烷在空气中爆炸火焰传播速度显著增大，最大火焰传播速度出现在距离点火端0.425 m（长径比等于6）处；火焰传播至长管末端壁面后，爆炸压力达到最大值；甲烷浓度越接近化学当量比，火焰传播速度越快；火焰传播速度随煤粉浓度和点火延迟时间的变化趋势为先增大后减小，最佳煤粉浓度为500 g/m³，最佳点火延迟时间为500 ms；在一定粒径范围内，火焰传播速度随着煤粉粒径的增大而减小。

Flame propagation of methane-coal dust explosion in closed vessel

Flame propagation of methane-coal dust compound explosion in different initial conditions in a 1.2 m long vertical pipe was quantitatively investigated. The effect of methane concentration, coal dust concentration, coal dust particle diameter and ignition delay on the flame propagation characterization was experimentally researched. The experimental results show that the flame velocity significantly increases in methane-coal dust explosion compared with methane-air explosion. The maximum flame velocity appears at the distance of 0.425 m from ignition position. Explosion pressure rises with the flame propagation and reaches the maximum pressure when the flame propagates to the end of the pipe. Flame propagation velocity is faster when the methane concentration closes to chemical equivalence ratio. Flame propagation velocity increases first and then decreases with the coal concentration and ignition delay time. The most dangerous condition of flame propagation is 500 g/m3 for dust concentration and 500 ms for ignition delay time. The flame velocity decreases when dust size increases.