To investigate the impact of multiple combustible gases produced by long-flame coal spontaneous combustion on the gas explosion limit and to guide the reoperation of the coal mine goaf and fire area, the influence of gas generated by coal spontaneous combustion on gas explosion limit is investigated in this paper using a temperature-programmed device and a 20 L spherical explosion device. The results show that the volume fraction of CO produced during the spontaneous combustion of coal samples is 0.47%, followed by CH₄ and C₂H₆, and C₂H₄ has the lowest content. Simultaneously, the coal spontaneous combustion is divided by 30°C, 80°C, and 170°C as the threshold, depending on the different gas characteristics. Organic C₂H₄ and C₂H₆ produced by coal spontaneous combustion have a greater impact on the CH₄ explosion limit than inorganic CO. The lower and upper limits of CH₄ explosion were reduced to 2.98% and 12.2%, respectively, by 0.8% C₂H₆. C₂H₄ and C₂H₆ explosion limits change dramatically when mixed with CH₄. The CO and CH₄ mixture explosion limit decreases first and then increases. C₂H₄ and C₂H₆ have a significant impact on the explosion pressure of mixed gas and the lower explosion limit of gas. The lower explosion limit falls from 5.1% to 4.3% as the explosion pressure rises from 0.25 MPa to 0.29 MPa.

中文翻译：

---

长焰煤自燃瓦斯对瓦斯爆炸极限的影响

为研究长焰煤自燃产生的多种可燃气体对瓦斯爆炸极限的影响，指导煤矿采空区和火区的再作业，研究了煤自燃产生的多种可燃气体对瓦斯爆炸极限的影响。本文采用程序升温装置和 20 L 球形爆炸装置。结果表明，煤样自燃过程中产生的CO体积分数为0.47%，其次为CH ₄和C ₂ H ₆，C ₂ H ₄含量最低。同时，煤的自燃根据不同的气体特性分为30℃、80℃、170℃为阈值。煤自燃产生的有机C ₂ H ₄和C ₂ H _{6对CH 4}爆炸极限的影响大于无机CO。CH 4 爆炸下限和上限_分别降低到2.98%和12.2%，通过0.8% C ₂ H ₆。当与 CH ₄混合时， C ₂ H ₄和 C ₂ H ₆的爆炸极限会发生显着变化。CO 和 CH ₄混合物爆炸极限先降低后升高。C ₂ H ₄和C ₂ H ₆对混合气体的爆炸压力和气体的爆炸下限有显着影响。随着爆炸压力从 0.25 MPa 上升到 0.29 MPa，爆炸下限从 5.1% 下降到 4.3%。