南京市各工程地质层热物性及分布特征研究

地层的热物性是地埋管地源热泵系统设计和运行中最重要的参数,本文通过测试南京市100 m深度范围内土层的常规物理参数及热物性参数,得到了各工程地质层的含水率、孔隙比、干密度、导热系数、比热容等,各工程地质亚层平均导热系数分布在1.322~2.443 W·m^-1·K^-1之间,其中最大、最小值分别为②4e、②1b4工程地质亚层。分析了土体常规物理参数与热物性参数的相关性,黏性土导热系数随着含水率的增加而减小,随着干密度的增加而增大,随着孔隙比的增加而减小,并得到了黏性土导热系数与含水率、孔隙比、干密度相关性的经验公式,为地埋管地源热泵的设计提供基础数据和理论支持。

The Distribution Characteristics of Thermal Conductivity and Specific Heat of each Engineering Geological Strata in Nanjing

Heat transfer performance is the key factor for the design and operation of the ground source heat pump. In order to analyze the routine physical parameters and the thermophysical parameters of each engineering geological strata group of Nanjing, large amounts of soil samples have been taken to test from less than 100 m depth layer. The testing parameters include the moisture content, void ratio, dry density, thermal conductivity, specific heat capacity, etc. The average thermal conductivity of each engineering geologic subhorizon ranges from 1.322 to 2.443 W·m^-1·K^-1. The maximum value is engineering geological subhorizon of ②4e, and the minimum value is ②1b4. Factors affecting the soil thermal conductivity are further explored. The correlations between the routine physical parameters and the thermophysical parameters of the soil are discussed. Thermal conductivity of the cohesion soil decreases with the soil moisture content augment or the soil void ratio augment, and increases as the soil dry density increases. Empirical formula is proposed for estimating thermal conductivity of the cohesion soil from the soil moisture content, the soil void ratio and the soil dry density. This study provides the basic data support and theoretical foundation for the ground source heat pump system design.