基于DTS技术的菏泽地层导热性研究

DTS TECHNOLOGY FOR THERMAL CONDUCTIVITY OF GROUND IN HEZE,SHANGDONG PROVINCE

为了确定山东省菏泽市某地区的地下热物性参数,本文基于线源热传导理论,将DTS技术与现场热响应试验(TRT)相结合,利用测温光缆对现场单U和双U地埋管加热(或冷却)过程的钻孔温度进行了分布式测定,对该地区每一地层的导热系数进行了计算。试验结果表明:利用DTS技术可在现场热响应试验中准确可靠地获得各个地层导热系数分布,评价各个地层的热交换能力;渗流对地层导热性具有显著的提高作用;双U管试验的测试结果比单U管试验所获得的结果更准确;受热量累积效应的影响,换能试验时间越长,所得到的导热系数越小,并逐渐趋于一稳定值。本研究成果可为地源热泵设计提供基本依据。

This paper attempts to determine the underground thermal properties of a region in Heze,Shandong Province. On the basis of the theory of line source,a field thermal response test was carried out using distributed temperature sensing technology（ DTS）. Temperature measurement cables were used to capture distributed temperatures of the borehole during heating or cooling process,under single and double U buried pipe conditions respectively. The thermal conductivities of each layer were subsequently calculated. The experimental results show that the thermal conductivity of different strata can be accurately and reliably obtained with DTS technology in the field thermal response test,and the heat exchange capacity of each stratum can be evaluated. There is a significant improving effect of seepage on the thermal conductivity. It is also found that the results obtained by the double Utube test are more accurate than that obtained by single U-tube test. Because of the heat accumulation effect,the longer the test time is,the smaller the thermal conductivity is. If the test time is long enough,the thermalconductivity would become a stable value. The results of this study can provide the basic basis for ground source heat pump design.