1. State Key Laboratory Cultivation Base for Gas Geology and Gas Control,Henan Polytechnic University,Jiaozuo　 454000,China; 2. School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo　 454000,China; 3. The Collaborative Innovation Center of Coal Safety Production of Henan,Jiaozuo　454000,China

为了研究温度冲击条件下的煤体渗透性变化规律及增透机制,利用恒温箱和液氮对原煤煤样进行了两种条件下的温度冲击试验,分析了煤样在温度冲击前后的渗透率变化情况和微观裂隙发育情况,探讨了温度冲击过程中的声发射信号分布规律。试验结果表明:在经过冷冲击处理和热-冷冲击处理后,煤体的渗透率平均增幅分别为48.68%和469.24%,热-冷冲击处理过程中煤样的声发射能量峰值是冷冲击处理过程中煤样的声发射能量峰值的3.6倍,相比冷冲击处理,热-冷处理所产生的微裂纹数量更多,裂隙呈树枝状发育,增透效果更好;煤体性质的各向异性和温度冲击所产生的超过煤体抗拉强度的热应力是主要的增透机制。

To study the change law of permeability of coal under the condition of temperature impact and the mecha- nism of increasing permeability,the temperature impact test of two kinds of conditions of coal samples were carried out using thermostat and liquid nitrogen,the permeability variation of coal samples before and after temperature shock and the development of micro fracture were analyzed,and the distribution of acoustic emission signal in the process of tem- perature shock was also discussed. The experimental results indicate that after the cold shock treatment and hot-cold shock treatment,an average increase of permeability of coal were 48． 68% and 469． 24% respectively,the AE energy peak during hot-cold impact process is 3． 6 times of that during the cold shock process. Compared with cold shock treatment,the hot-cold impact process produces more number of crack,the fractures show a dendritic development,and the effect of increasing permeability is better. The thermal stress exceeding the tensile strength of coal produced by the anisotropy and thermal shock properties of coal is the main mechanism of increasing permeability.

WEI Jianping,SUN Liutao,WANG Dengke,et al. Change law of permeability of coal under temperature impact and the mechanism of in- creasing permeability[J]. Journal of China Coal Society,2017,42(8):1919-1925.