随温度升高煤岩体渗透率减小或波动变化的细观机制

 采用在线加热同步观测煤岩样孔隙结构演变的实验方法，对常温～350 ℃时的贫煤和花岗岩试件进行细观结构演化研究，得出以下结论：(1) 相同条件下，兼具固体颗粒和纯孔隙的子网格受温度作用更为明显，孔隙变化更大。由于该孔隙为多孔介质的吼道孔隙，故孔隙大小的变化会对煤岩渗透率造成显著影响；(2) 温度升高时，花岗岩和大部分贫煤样品的渗透率具有先增大后减小的特性，少数贫煤样品的渗透率呈现单调下降趋势；(3) 煤岩样孔隙率越小，其孔隙率单调降低的临界温度点越低。热力耦合作用下同步分析煤岩体细观结构的演变，进而探求其宏细观对应规律，已成为岩石渗流力学研究的重要趋势。

Meso-mechanism of permeability decrease or fluctuation of coal and rock with the temperature increase

The meso-structure evolution of coal and granite samples at normal temperature to 350 ℃ was studied by means of on-line heating and synchronous observation. Under the same conditions，the sub meshes with solid particles and pure pores are affected by the temperature more obviously，and the pores are larger. As these pores are throats of porous media，the change of their sizes have a significant effect on the permeability of coal and rock. The permeability of granite and most of the meager coal samples increase first and then decrease with the increase of temperature，while a few meager coal samples show a monotone downward trend. The smaller the coal porosity is，the lower the critical temperature of porosity decreasing.