ABSTRACT

To investigate the actual gas explosion and propagation laws in the roadway of an underground mine, experiments were conducted in a standard 19-L tube of rectangular section to provide a comprehensive understanding of the effects of carbon monoxide (CO) addition and obstacles placed on the flame propagation of explosions from methane–air mixtures at different conditions. The flame structure, flame propagation speed, heat loss, and explosion pressure were used to reflect the explosion behaviors of the premixed flame. The experimental results indicate that the enhancement and attenuation of the explosion pressure wave are significantly influenced by an obstacle. The existence of obstacles changed the trend of classical pressure rise, thus forming a first pressure peak. In addition, the position close to the obstacle presented a higher explosion pressure. Under 7 vol.% and 9.5 vol.% CH₄ conditions, the increase of CO (from 0 vol.% to 2 vol.%) promoted explosion flame propagation. However, the CO exhibited a clear negative effect on the rate of flame propagation due to exacerbated O₂ depletion of 11 vol.% CH₄, and the negative effect enhances with CO increased. Besides, when the CO addition increased, the flame tended to more instability and more brightly. For heat loss, with the increase of CO content in mixed gases, there was a slight promoting, constant and inhibiting effect for 11 vol.%, 9.5 vol.%, and 7 vol.% CH₄, respectively. These results are of fundamental importance for the prevention and mitigation of gas explosion in underground mines and other industrial scenarios.

摘要

为了研究地下矿井巷道中的实际瓦斯爆炸和传播规律，在矩形截面的标准 19 L 管中进行了实验，以全面了解一氧化碳 (CO) 添加的影响和对井道设置的障碍。不同条件下甲烷-空气混合物爆炸的火焰传播。火焰结构、火焰传播速度、热损失和爆炸压力用来反映预混火焰的爆炸行为。实验结果表明，爆炸压力波的增强和衰减受到障碍物的显着影响。障碍物的存在改变了经典压力上升的趋势，从而形成了第一个压力峰值。此外，靠近障碍物的位置呈现出更高的爆炸压力。低于 7 vol.% 和 9.5 vol.% CH_{在 4 个}条件下，CO 的增加（从 0 vol.% 到 2 vol.%）促进了爆炸火焰的传播。然而，由于11 vol.% CH _{4 的}O ₂消耗加剧，CO 对火焰传播速率表现出明显的负面影响，并且负面影响随着 CO 的增加而增强。此外，当CO添加量增加时，火焰趋于不稳定和明亮。对于热损失，随着混合气体中CO含量的增加，11 vol.%、9.5 vol.%和7 vol.% CH ₄分别有轻微的促进、恒定和抑制作用。这些结果对于预防和缓解地下矿井和其他工业场景中的瓦斯爆炸具有重要意义。