微米级褐煤粉尘爆炸压力试验研究

Experimental study on explosion pressure of micron lignite dust

使用近球形煤尘爆炸装置,以微米级褐煤粉尘为研究对象,测试爆炸压力特性变化规律。研究表明:微米级褐煤粉尘爆炸最大压力为0.73MPa,最大压力上升速率为65.78MPa/s,该爆炸强度可对爆源附近人员造成极大危害。爆炸前后参与爆炸的挥发分质量分数达到26.25%,表明挥发分是参与褐煤粉尘爆炸的主体成分。随喷尘压力在1.4~2.6MPa范围内增大,爆炸最大压力和最大压力上升速率均先增大后减小。喷尘压力为1.8~2.2MPa时,爆炸最大压力相对较大,表明该条件下褐煤粉尘在点火头附近扩散得最充分。随点火延迟时间在70~130ms范围内增大,爆炸最大压力和最大压力上升速率均先增大后减小,最佳点火延迟时间约为100ms,说明该条件下褐煤粉尘颗粒达到最佳分散状态,爆炸强度最大。

A near spherical coal dust explosion experimental de-vice was used to test and analyze the change law of explosion pressure characteristics with micron lignite dust as the research object.The research shows that the maximum pressure of mi-cron lignite dust explosion is 0.73 MPa,and the maximum pres-sure rise rate is 65.78 MPa/s.The explosion intensity can cause great harm to people near the explosion source.The mass frac-tion of volatile matter involved in the explosion reached 26.25%,indicating that volatile matter is the main component involved in the explosion of lignite dust.When the dust injec-tion pressure is between 1.4 MPa and 2.6 MPa,the maximum explosion pressure and the maximum pressure rise rate first in-crease and then decrease.When the dust injection pressure is 1.8~2.2 MPa,the maximum explosion pressure is relatively large,indicating that the lignite dust diffuses most fully in the area near the ignition head under this condition.As the increase of the ignition delay time from 70 ms to 130 ms,the maximum explosion pressure and the maximum pressure rise rate both in-crease first and then decrease,and the optimal ignition delay time is about 100 ms,indicating that under this condition,lig-nite dust particles reach the best dispersion state,so that the ex-plosion intensity can be maximized.