构造煤渗透率对温度变化响应规律的试验研究

针对含瓦斯构造煤渗透率与温度变化关系，利用自主研发的含瓦斯煤岩热-流-固耦合三轴渗流试验装置，开展不同应力条件下含瓦斯构造煤原煤样的渗透率与温度变化的试验研究。试验结果表明：（1）在试验温度变化过程中，构造煤样渗透率随温度升高而降低，渗透率与温度变化呈现负指数函数分布规律；（2）在试验温度变化过程中，构造煤渗透率损失率与有效应力符合Boltzmann分布，渗透率损失率存在有效应力门槛值大约为4.515 MPa。渗透率变化主要分为渗透率加速变化与平稳变化两个阶段，构造煤样渗透率从加速阶段过渡到平稳变化温度大约为45 ℃；（3）在温度21～80 ℃范围内，渗透率敏感性系数数量级为10-2，温度变化对构造煤样渗透率影响不显著。同时，有效应力的增加使得温度敏感性系数降低。

An experimental study on response law of permeability of tectonic coal samples to temperature variation

To investigate the relationship between the permeability and temperature of tectonic coal containing gas, a series of tests on tectonic coal samples containing gas is carried out at different stress conditions using a self-developed triaxial hot-fluid-solid coupling seepage testing device. Experimental results show that the permeability of tectonic coal samples decreases with the increase of temperature, and there is a negative exponential function relation between permeability and temperature. Moreover, the relationship between the permeability loss rate and the effective stress follows the Boltzmann distribution with the variation of experimental temperature. There exists an effective stress threshold of approximately 4.515 MPa for the permeability loss rate. There are two stages identified in permeability change of tectonic coal, i.e. the accelerating stage and the smooth stage, and the transition temperature from the accelerating phase to smooth phase is about 45 ℃. Within the range of 21-80 ℃, the sensitivity order of the permeability coefficient is 10-2, which means the effect of temperature on permeability of tectonic coal sample is not obvious. At the same time, the increase of effective stress results in the decrease of the temperature sensitivity coefficient.