点火延迟时间对甲烷煤尘爆炸特性的影响

为研究不同湍流环境下,煤尘对甲烷爆炸特性的影响,基于20 L爆炸球采用0、25、50、100、200 g/m^3的煤尘分别与6.5%、9.5%、12%的甲烷在点火延迟时间60 ms和120 ms的条件下进行混合爆炸实验。结果表明:点火延迟时间的增大对单相甲烷爆炸最大爆炸压力影响较小,显著降低最大压力上升速率;有煤尘参与时,3种甲烷浓度下,点火延迟时间的提高能够降低最大爆炸压力和最大压力上升速率,当甲烷浓度为9.5%时,2种点火延迟时间下,对应的最佳煤尘浓度不同,点火延迟时间越小,最佳煤尘浓度越小,甲烷浓度为12%时,点火延迟时间为60 ms时,最大爆炸压力和最大压力上升速率对高浓度煤尘比较敏感,火延迟时间为120 ms时,最大爆炸压力和最大压力上升速率对低浓度煤尘较为敏感。

Effect of Ignition Delay Time on Explosion Characteristics of Methane and Coal Dust Hybrid Mixtures

To study the effect of coal dust on methane explosion characteristics under different turbulent environments,based on 20 L explosion sphere,the mixed explosion experiments of 0 g/m^3,25 g/m^3,50 g/m^3,100 g/m^3,200 g/m^3 coal dust and 6.5%,9.5%,12%methane hybrid mixtures were obtained under the condition of ignition delay time 60 ms and 120 ms,respectively.The results show that the increase of the ignition delay time has a small effect on the maximum explosion pressure of methane explosion,and reduces the maximum pressure rise rate significantly.When coal dust is involved,the increase of the ignition delay time can reduce the maximum explosion pressure and the maximum pressure rise rate under the three methane concentrations.When the methane concentration is 9.5%,the optimal coal dust concentration is different under the two kinds of ignition delay time.The smaller the ignition delay time is,the smaller the optimal coal dust concentration is.The methane concentration is 12%,when the ignition delay time is 60 ms,the maximum explosion pressure and the maximum pressure rise rate are more sensitive to high concentration coal dust,when the ignition delay time is 120 ms,the maximum explosion pressure and the maximum pressure rise rate are more sensitive to low concentration coal dust.