红砂岩结构面热阻特性及其影响的实验研究

Experimental research on the characteristics and influence of thermal resistance of joints in red sandstone

结构面传热特性是决定岩体传热效率的关键问题因素,但目前有关结构面热传递过程中其热阻特性的实验研究较少。该文采用红砂岩作为研究对象,进行单裂隙红砂岩传热实验,采用稳态法测出结构面热阻,分析面积比、填充物厚度以及压力对热阻的影响。结果表明:裂隙面热阻与面积比呈抛物线型增长关系;当裂隙中填充物厚度由0逐渐增加至0.8 mm时,粗糙裂隙面热阻随着填充物厚度增加呈抛物线型增长趋势;当压力由0增长至500 N时,平直和粗糙裂隙面热阻均随着外加压力的增加呈抛物线型减小趋势,减幅逐渐减小。该研究取得的成果可为准确刻画红砂岩结构面传热特性提供实验依据。

The heat transfer through rock discontinuity plays a key role in the heat transfer efficiency of rock masses.However,there are rare studies concerning on the thermal resistance measurements.In this paper,red sandstone with a single-fracture is used as heat transfer test.The thermal resistance of the fracture surface is measured by the steady-state method.The parameters such as the effect of area ratio,filling thickness and pressure on thermal resistance are determined and analyzed.The results show that the thermal resistance of the fracture surface increases in a parabolic manner with increasing the area ratio.When the thickness of the filling materials in the crack gradually increases from 0 to 0.8 mm,the thermal resistance of the rough crack surface shows a parabolic growth trend.By increasing the normal pressure from 0 to 500 N,thermal resistance shows a parabolic decrease trend.The findings obtained in this research provide experimental basis for accurately characterizing the heat transfer characteristics of joints in red sandstone.