燃料物性参数对瓦斯煤尘复合爆炸的耦合作用

为研究瓦斯煤尘复合爆炸影响因素的耦合规律,对煤粉质量浓度、甲烷体积分数、煤粉粒径、煤粉种类等4种影响因素进行了多因素与单因素实验分析。通过正交实验,将各因素对爆炸的影响进行了定量分析,结果表明,4个因素对最大爆炸压力p_(max)的影响由强到弱依次为:甲烷体积分数、煤粉质量浓度、煤粉种类、煤粉粒径;对最大爆炸压力上升速率(dp/dt)_(max)的影响程度由强到弱依次为:甲烷体积分数、煤粉质量浓度、煤粉粒径、煤粉种类。对于体积分数为9%、11%的甲烷,复合体系的p_(max)随煤粉的质量增加而减小。当煤粉质量浓度增加到100、200 g/m3时,在与体积分数为6%的甲烷耦合作用下,会产生更强的“激励”作用,且煤粉浓度较大时,挥发分低的煤种最佳瓦斯浓度会降低。甲烷体积分数存在临界值,该临界值会改变挥发分因素的影响方式:低于此临界值时,高挥发分煤尘体系的(dp/dt)_(max)更高,(dp/dt)_(max)来临时间更短;高于此临界值时,低挥发分体系具有更高的爆炸强度。粒径影响挥发分的作用,粒径越大,挥发分的影响差异越明显。当甲烷体积分数为11%时,挥发分高的煤尘更容易受粒径的影响,直径小的煤尘体系,爆炸系数Kst更小;而低挥发分煤粉在甲烷体积分数接近当量时受粒径影响更明显。

Comparative experimental study on inhibiting gas explosion using ABC dry powder and diatomite powder

Using a 20 L spherical explosion suppressing test system, the largest gas explosion pressure and maximum pressure rising rate with additives of ultra-fine ABC dry powder and diatomite powder were tested and compared, and the explosion suppression effect of the two kinds of powder was analyzed. Experimental results show that both powders can suppress gas ex- plosion and ABC dry powder is superior to diatomite powder. Adding two powders under the same experimental conditions, when methane concentration is 7.0%, the maximum explosion pressure decreased 39% and 4%, respectively, while the rising rate of the maximum pressure decreased 80% and 53%, respectively. When methane concentration is 9.5%, the maximum ex- plosion pressure decreased 14% and 12%, respectively, the rising rate of maximum pressure decreased 62% and 27%, respec- tively, the maximum explosion pressure decreased 23% and 18%, respectively, while the rising rate of the maximum pressure decreased 77% and 70%, respectively. When methane concentration is 12.0%, the explosion suppression effect of ultra-fine ABC dry powder is not affected by the methane concentration, and the explosion suppression effect of diatomite powder under high methane concentrations is more obvious.