瓦斯煤尘共存条件下的煤尘云爆炸下限

近年来瓦斯煤尘共存条件下的爆炸事故呈多发趋势。运用20 L爆炸特性测试系统，对瓦斯煤尘共存复合体系的爆炸特性进行实验研究，得到了瓦斯在不同点火能量、静止及湍流状态下的爆炸下限，以及不同条件下煤尘的爆炸下限。结果表明:随着瓦斯浓度的增加，煤尘的爆炸下限呈指数衰减；瓦斯浓度存在某临界点，高于此临界点，复合体系爆炸过程中瓦斯起主导作用，表现为"强瓦斯"性，反之，煤尘起主导作用，表现为"强煤尘"性。研究结论为有效预防煤矿井下瓦斯煤尘共存爆炸事故提供重要的理论依据。

Minimum explosive concentration of coal dust cloud in the coexistence of gas and coal dust

The present work was carried for the prevention of increasingly ever prevalent gas explosion accidents that had occurred in the coexistence of gas and coal dust in recent years. Using a 20 L explosion test system, we studied experimentally the explosive characteristics of the coexisting gas and coal dust and obtained the lower limit of gas explosion under different ignition energies, static and turbulent conditions and the lower limit concentration of coal dust explosion under different conditions. The results show that with the increase of gas concentration, the minimum explosive concentration of coal dust cloud decreases exponentially and that there is a critical gas concentration, in higher than which gas plays a leading role in the process of explosion, shown as the so-called "strong gas". Otherwise, coal dust plays the leading role, which is characterized by the "strong coal dust". The conclusions can serve as an important theoretical basis for preventing the coal mine gas and coal dust explosion.