热模拟实验中低变质煤的突出参数变化特征

Change features of outburst parameters in the thermal simulation experiment of low metamorphic coal

为了研究瓦斯突出煤体的演化过程,采用煤化变质热模拟实验装置对煤样进行热模拟实验,分析不同实验温度条件下煤样的产气量、气体组分及加热前后煤体结构性能参数的变化规律。结果显示:在较高的实验温度下(450℃)产生的气体总量比较低温度(200℃)下大得多,前者的产气量几乎是后者的10倍,且相应的煤挥发分、坚固性系数和瓦斯放散初速度变化了5~7倍;350℃左右是低变质煤热解大量产生CH——4和焦油的临界温度,且在此温度时,低变质煤的坚固性系数和瓦斯放散初速度值已经超过突出煤层鉴定指标。由此认为,温度能改变煤体化学结构并产生瓦斯气体,且大量瓦斯气体的生成改变了煤的物理结构,其综合作用表现为煤体更易破碎,其突出危险性增加。

In order to study the evolution and preparation process of the gas outburst of coal body,we put the low metamorphic coal in sealed reactor under the action of heating to metamorphose and generate gas,maybe develop into coal and gas mixture with outstanding potential.In this way,we carry out the coal and gas outburst simulation experiment on inoculation evolution appearance.Research results show that the total amount of gas produced at relatively high experimental temperatures（450℃） is more than the total amount of gas produced at relatively low experimental temperatures（200℃）,the production of the former is almost 10 times than the latter,and the corresponding Vdaf,f and ΔP change 5 to 7 times.It indicates that temperature could change the chemistry structure of coal and then produce gas,and gas changes the physical structure when gas is produced.Their comprehensive effect increases the risk of coal outburst danger.It can be inferred from the experiment that along with the temperature increasing,the degree of coal metamorphism deepening,coal is more likely to be broken,the danger of coal outburst increases too.