甲烷爆炸是矿井生产中的重大灾害。通过20L密封的球形爆炸罐，实验测试了体积百分比浓度为6％～9％的甲烷爆炸过程中罐内压力的变化，建立了据实验结果计算爆炸过程温度、转化率及各组分浓度等重要参数的数学模型，实现爆炸过程定量研究。研究表明，实验浓度范围内，甲烷初始浓度越大，爆炸最高温度越高，达到最高温度点和终止反应的时间越短，反应最高转化率越大，反应越剧烈。甲烷初始浓度为6％和7％时，爆炸温度变化率和甲烷转化率变化率曲线各出现两个明显的峰，随着甲烷初始浓度升高，第一个峰高度增大，第二个峰高度降低，到甲烷浓度9％时仅剩第一个峰。理论分析认为，第一个峰是自由基链反应、第二个峰值则主要是热着火的结果。本研究对瓦斯爆炸危害评估及预防有重要的作用。%Gas explosion is one of the most serious disasters in mine production.In a 20L enclosed near-global ex-plosion testing tank, a series of explosion experiments were conducted with methane molecular fraction ranging from 6% to 9%, and the pressure change in the tank was real-time recorded during experiments.A mathematical model was set up for calculating temperature, conversion rate of methane and concentration of different gas species.It proved that in the range of tested methane concentration, the larger the methane concentration, the higher the high-est explosion temperature in the tank, and the shorter the time needed to attain the highest temperature and to finish the reaction, and the larger the highest conversion rate, the more violence the explosion.As the initial molecular fraction of methane is 6%and 7%, there appear two apparent peaks in the curves of explosion temperature change rate and methane conversion rate to time.As the initial methane concentration rises, the height of the first peak in-creases and the second peak decreases, until only the first peak left when initial methane molecular fraction rises to 9%.Theoretical analysis showed that the first peak is due to free radical reaction and the second one is due to heat ignition.This study is important for risk evaluation and prevention of gas explosion.
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