基于线热源理论的岩土体现场热响应试验研究

Study on geotechnical field thermal response test based on lineal heat source theory

为了准确获得地下岩土体热物性参数,基于线热原模型理论,详细分析了岩土体热物性现场热响应测试的理论模型及数据处理方法。以丹阳市滨江新城DYG084号100m深单U型垂直埋管试验孔恒热流散热试验为例,采集现场测试数据得到埋管供回水温度响应曲线,采用了基于线热源模型的数据拟合法对试验数据进行分析处理。数据分析表明,土壤的初始地层温度为19.23℃,夏季工况下,岩土体综合导热系数、容积比热容和钻孔内热阻分别为2.29W/(m·K)、2.33×106J/(m3·K)和0.143(m·℃)/W;试验表明,本文所建立的地下岩土体热物性测试数据分析模型是可行的,可应用于实际地源热泵工程地下岩土体热物性测试数据的处理分析。

In order to accurately obtain the thermal properties of the in-situ ground,an analysis on the theoretical model and the data processing method of thermal response test based on the theory of lineal heat source are introduced in detail. Vertical single U-tube test well with depth of 100 m is taken as a testing.The original ground temperature and the inlet and outlet water temperature response curve of the underground heat exchanger are also obtained,and thermal parameters of ground are collected through field test data fitting method based on lineal heat source model. Results show that the initial formation temperature of the soil is 19. 23℃. Under summer conditions,the geotechnical comprehensive coefficient of thermal conductivity is 2. 29 W /（ m·K）,the volumetric heat capacity and borehole thermal resistance are 2. 33 × 106 J /（ m3·K） and 0. 143m·℃ /W respectively. The experimental validation shows that the analysis model proposed in this paper are feasible and can be used in the practical ground source heat pump project for determination of ground thermal properties.