不同变质程度煤尘爆炸压力特性变化规律实验研究

为研究不同变质程度煤尘爆炸压力特性变化规律,以最大压力pmax和最大压力上升速率(dp/dt)max表征压力特性,使用近球形煤尘爆炸装置对褐煤、长焰煤、不黏煤和气煤的爆炸压力特性变化规律展开分析。研究发现:在4种煤尘样品中,褐煤的pmax和(dp/dt)max均最大,分别达0.71 MPa和65.69 MPa/s。随变质程度增大,长焰煤、不黏煤和气煤的pmax和(dp/dt)max均明显减小,说明以爆炸压力特性为标准,4种煤尘爆炸强度由高到低依次是褐煤、长焰煤、不黏煤和气煤。通过对比爆炸前后煤尘挥发分含量,得出参与爆炸的挥发分含量所占质量分数为46.28%~68.19%。在喷尘压力 p0=2.0 MPa,点火延迟时间t0=100 ms时,4种煤尘pmax值均达最大,分别为0.71、0.60、0.55和0.47 MPa。褐煤、不黏煤和气煤在 p0=2.0 MPa,t0=80 ms时(dp/dt)max达最大,而长焰煤则在 p0=2.0 MPa,t0=100 ms时(dp/dt)max达到最大。

Experimental study on explosion pressure variation law of coal dust with different degrees of metamorphism

In order to study the variation law of coal dust explosion pressure with different metamorphic degrees, the maximum pressure pmax and maximum pressure rise rate (dp/dt)max are characterized. The variation of explosion pressure characteristics of lignite, long flame coal, non-coking coal and gas coal is investigated by using a near-spherical coal dust explosion device. It is found that, among the selected coal dust samples, lignite has the largest pmax and (dp/dt)max, up to 0.71 MPa and 65.69 MPa/s, respectively. With the increase of metamorphism, the pmax and (dp/dt)max of long-flame coal, non-coking coal and gas coal are significantly reduced. Characterizing the explosion intensity by the explosion pressure characteristics, the four coal dust explosion strengths are then ranked from lignite, long flame coal, non-coking coal to gas coal. By comparing the volatile matter content of coal dust before and after the explosion, it is concluded that the proportion of volatile matter involved in the explosion is 46.28%.68.19%. At dispersion pressure p0= 2.0 MPa and ignition delay time t0=100 ms, the pmax values of the four types of coal dust reach the maximum 0.71, 0.60, 0.55 and 0.47 MPa, respectively. However, lignite, non-viscous coal and gas coal have the highest (dp/dt)max at p0=2.0 MPa and t0=80 ms, while long-flame coal reaches the maximum (dp/dt)max at p0=2.0 MPa and t0=100 ms. The results are of significance for mastering explosion pressure characteristics under different test conditions.