砂岩和灰岩热导率温度作用效应的实验研究

发布时间：2019-02-20 19:23

【摘要】：高温作用会导致岩石内部结构发生变化,并对其热物理性质产生显著影响,因此,研究高温作用后岩石热物理性质的变化规律对地热系统及存在热流传播问题的地下工程具有指导意义。实验以高温作用后砂岩、灰岩为研究对象,利用热常数分析仪研究了砂岩、灰岩热导率随温度的变化特征,并结合岩石微观结构特性,从矿物受热的微观机理出发,对岩石热导率变化的内在机理进行了初步探讨。结果表明,砂岩热导率可分为25~100℃、100~400℃、400~600℃和600~900℃四个阶段,灰岩热导率可分为25~100℃和100~400℃两个阶段,砂岩、灰岩在25~400℃间由于水分的蒸发热导率整体变化较快,400℃以后矿物发生相变及分解、熔融等物理化学反应,从而微裂缝发育、延伸,并连接形成宏观裂隙,砂岩热导率急剧下降,灰岩内部结构较完整,微裂隙发育较少,热导率基本稳定。
[Abstract]:The high temperature will lead to the change of the internal structure of the rock and have a significant effect on its thermo-physical properties. The study of the variation of the thermal physical properties of rocks after high temperature action is of great significance to the geothermal system and underground engineering with heat flux propagation problem. The thermal conductivity of sandstone and limestone under high temperature is studied by means of thermal constant analyzer. The characteristics of thermal conductivity of sandstone and limestone with temperature are studied, and the microstructure of rock is combined with the microscopic mechanism of mineral heating. The internal mechanism of rock thermal conductivity variation is discussed. The results show that the thermal conductivity of sandstone can be divided into four stages: 25 鈩，

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