This study is aimed at investigating the characteristics of CH₄ explosion diffusion and propagation to the non-methane area. The CH₄ explosion pressure and flame were tested with the aid of a self-built horizontal pipeline system. On this basis, the flame images, photoelectric signals, and pressure propagation laws during explosions of methane with different volume fractions in the pipeline were obtained. The experimental research results indicate that an obvious secondary explosion pressure occurs at L/D = 3.5. After the explosion pressures at different positions along the entire pipeline reach the peak values, they experience varying degrees of oscillations. The maximum explosion pressure in the non-methane zone may occur at different length-to-diameter ratios. When the volume fraction of CH₄ is larger, the maximum explosion pressure occurs farther. However, the explosion pressure at the end of the pipeline is lower than that at the explosion source. The flame intensity and flame duration of methane explosion are remarkably enhanced at L/D = 17.5 and then become gradually weakened in the non-methane area. The variations of explosion pressure are always prior to those of flame signal. CO and CO₂ are the main toxic and harmful gases produced by methane explosions, and high-concentration (13% in this experiment) methane explosions produce a small amount of hydrocarbon gases such as C₂H₄ and C₂H₆. The volume fractions of the gases produced decrease with the increase in the distance from the explosion source. The research results boast great significance for suppressing methane explosions and their propagation in the pipeline.

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连通室中甲烷爆炸火焰及压力波向非甲烷区传播特性研究

本研究旨在研究CH ₄爆炸扩散和传播到非甲烷区域的特征。借助自建的水平管道系统对CH _{4爆炸压力和火焰进行了测试。}在此基础上，获得了管道内不同体积分数甲烷爆炸过程中的火焰图像、光电信号和压力传播规律。实验研究结果表明，在L / D处出现明显的二次爆炸压力 = 3.5。整个管道不同位置的爆炸压力达到峰值后，会出现不同程度的振荡。非甲烷区的最大爆炸压力可能以不同的长径比出现。CH ₄的体积分数越大，最大爆炸压力出现得越远。但管道末端的爆炸压力低于爆炸源处的爆炸压力。甲烷爆炸的火焰强度和火焰持续时间在L / D =17.5时明显增强， 然后在非甲烷区域逐渐减弱。爆炸压力的变化总是先于火焰信号的变化。一氧化碳和一氧化碳₂是甲烷爆炸产生的主要有毒有害气体，高浓度（本实验中为13%）甲烷爆炸产生少量的C ₂ H ₄和C ₂ H ₆等烃类气体。所产生气体的体积分数随着与爆炸源距离的增加而减小。该研究成果对抑制甲烷爆炸及其在管道中的传播具有重要意义。