常温土壤导热系数的试验及预测研究

Experimental and Predictive Study of Thermal Conductivity of Room Temperature Soil

探究土壤导热系数的变化规律,对地源热泵系统和土壤储热等领域具有重要意义。利用TEMPOS热性能分析仪对不同干密度、不同饱和度下黄土和砂土导热系数变化规律进行研究。结果表明,饱和度、干密度均对土壤导热系数影响显著,黄土、砂土的导热系数随饱和度的增加总体呈增大趋势,但黄土和砂土的导热系数变化规律差异明显;黄土和砂土的导热系数随干密度的增大而增加,但黄土较砂土变化幅度较小。根据试验数据对16种预测模型进行评价,结果表明,CCM模型表现最好。

It is of great significance to explore the variation law of soil thermal conductivity for fields of ground source heat pump systems and soil heat storage.The thermal conductivity variation law of loess and sandy soils with different dry densities and different saturations was investigated by TEMPOS thermal performance analyzer.The results show that saturation and dry density both have significant effects on the thermal conductivity of soil.The thermal conductivity of loess and sandy soil shows an overall increasing trend with the increase of saturation,but there is an obvious difference in the change pattern of thermal conductivity of loess and sandy soil.The thermal conductivity of loess and sandy soil increases with the increase of dry density,but the change range of loess soil is smaller than that of sandy soil.At the same time,16 prediction models are evaluated based on the experimental data and the results show that the CCM model performs the best.