煤层气化上覆岩层温度场分布规律研究

由于温度对岩石的影响作用,高温下岩体的物理力学性能及破坏规律与常温下岩体的大不相同;通过对气化炉上覆岩层岩石导热系数试验,取得了不同温度下岩石的导热系数及规律方程,采用comsol多物理场耦合软件进行传热数值计算。研究表明:岩石的导热系数随温度增加呈下降趋势,随岩性不同下降的速度基本相同;在不同的温度下,各岩性的导热系数有一定的差异。通过模拟软件的分析得到了煤层气化上覆岩层温度分布随高度方向变化的规律,温度下降梯度随岩性不同而不同。这一结果为进一步研究煤炭地下气化上覆岩层强度变化及破坏规律提供了理论指导。

Temperature Field Distribution in Overburden with Coal Seam Gasification

Due to the effect of temperature on the rock,rock’s physical and mechanical properties and destruction rules under the high temperature are different from that under normal temperature.Through the experiment on the coefficient of thermal conductivity of the overlaying strata rock,we get the coefficient of thermal conductivity of the rock and rule equation under different temperatures.Using comsol multi-physical coupling software,we calculate the value of heat transfer.The result shows that: the thermal conductivity of rock declines with temperature increasing.The speeds of the decline are the same for different lithology.Under different temperatures,the thermal conductivity of the lithology is of certain differences.With the help of the simulation software,the variation rule of the temperature distribution of the overlaying strata is obtained.Temperature gradients vary for different types of rock The results provide theoretical guidance for further study on the strength variation and damage rule of the overlaying strata in the process of underground coal gasification.