如何有效预防和控制煤自燃环境中瓦斯爆炸事故是矿井火区亟待解决的重要课题。针对矿井火区中煤自燃引发的瓦斯爆炸具有环境温度高、参与爆炸的可燃性气体成分复杂等特点，本文选取CH4、CO、H2、C2H6、C2H4代表性气体为研究对象。将其他四种可燃气体以五种比例配制后分别加入三种典型浓度的甲烷中，利用可视化气体与粉尘球形爆炸实验系统和高速摄影仪，获取其爆炸压力特性参数，并采集爆炸火焰传播图像，研究初始温度、其他四种混合气体浓度对甲烷爆炸特性及火焰传播行为的影响。为矿井火区中多元可燃气体爆炸防控与危险性预测提供依据。 研究发现，加入五种配比的任一配比后，随着初始温度的升高，7%甲烷-空气混合物的最大爆炸压力非线性下降，到达最大爆炸压力的时间呈缩短的趋势，最大爆炸压力上升速率呈几乎恒定或下降的趋势。同样，对于9.5%甲烷-空气混合物和11%甲烷-空气混合物，初始温度的升高使其最大爆炸压力与最大爆炸压力上升速率呈现下降趋势。但初始温度的升高使9.5%甲烷-空气混合物到达最大爆炸压力的时间在一定范围内波动或呈缩短的趋势，11%甲烷-空气混合物到达最大爆炸压力的时间缩短。 同一初始温度下，随着五种配比混合气体浓度的增大，对于7%甲烷-空气混合物，其最大爆炸压力与最大压力上升速率均呈增大的趋势，达到最大爆炸压力的时间明显缩短。对于9.5%和11%甲烷-空气混合物，其最大爆炸压力与最大爆炸压力上升速率均呈减小趋势，且延长了到达最大爆炸压力的时间。值得注意的是，其他四种可燃气体的存在对7%甲烷爆炸特性的影响更大。 采用MATLAB软件自编程序进行图像处理获取火焰传播距离，并对其拟合后得出瞬时火焰传播速度，在可见视窗范围内，以配比1为例，初始温度为298K时，7%、9.5%和11%甲烷-空气混合物的火焰传播速度峰值分别为1.23m/s、2.15m/s、1.78m/s。同一多元可燃气体浓度下，随着初始温度由313K增加到353K时，其最大火焰传播速度不同程度地增大。同一初始温度下，将其他四种多元可燃气体以五种不同配比加入甲烷后，使7%甲烷-空气混合物的最大火焰传播速度不同程度地增大，9.5%和11%甲烷–空气混合物的最大火焰传播速度不同程度地减小。

How to prevent and control gas explosion accidents effectively in the environment of coal spontaneous combustion is an important issue to be solved urgently in mine fire areas. The gas explosion caused by spontaneous combustion of coal has many features, such as high temperature and multiple combustible gases coexisting. In this paper, representative gases of CH4, CO, H2, C2H6 and C2H4 were selected as research object. The other four combustible gases were prepared in five ratios and then added into three typical concentrations of methane. The visualized gas and dust spherical explosion experimental system and high-speed camera were used to obtain the explosion pressure characteristic parameters, and the propagation image of explosion flame was taken. And then the effects of initial temperature and concentration of the other four mixed gas components on methane explosion characteristics and flame propagation behavior are studied. This paper provides a basis for prevention and control of mine gas mixture explosion and its risk prediction. Research indicates: After adding 5 kinds of mixed gas of any ratio, the maximum explosion pressure of 7% CH4-air mixture decreases nonlinearly with the increase of the initial temperature, and the corresponding time to reach maximum explosion pressure is shortened. The maximum rate of pressure rise is almost constant or decreasing. Similarly, for the 9.5% CH4-air mixture and the 11% CH4-air mixture, the maximum explosion pressure and the maximum rate of pressure rise decrease as the initial temperature increases. However, as the initial temperature increases, the corresponding time to reach maximum explosion pressure of the 9.5% CH4-air mixture fluctuates or shortens within a certain range. For the 11% CH4-air mixture, the time to reach the maximum explosion pressure is shortened. At the same initial temperature, for the 7% methane-air mixture, with the increase of the concentration of the five ratios, the maximum explosion pressure and the maximum rate of pressure rise all show an increasing trend, howbeit the corresponding time to reach maximum explosion pressure is significantly shortened trend. For the 9.5% and 11% methane-air mixtures, both the maximum explosion pressure and the maximum rate of pressure rise are reduced and the corresponding time to reach maximum explosion pressure is extended. It is worth noting that the presence of the other four combustible gases has a greater impact on explosive properties of a 7% methane-air mixtures. The MATLAB software was used to process the image to obtain the flame propagation distance, and the instantaneous flame propagation speed was obtained after fitting. In the visible window range, taking the ratio 1 as an example, at 298 K, the flame propagation speed peaks of the 7%, 9.5% and 11% methane-air mixtures were 1.23m/s, 2.15m/s and 1.78m/s, respectively. Under the same multi-combustible gas concentration, the maximum flame propagation speed increases with different degrees as the initial temperature increases from 313K to 353K. And at the same initial temperature, after adding the other four combustible gases to methane in five different ratios, the maximum flame propagation velocity of 7% methane-air mixture rise with different degrees, but the maximum flame propagation velocity of the 9.5% and 11% methane-air mixture decline with different degrees.