A study of effective thermal conductivity in the North China Plain based on in situ thermal response tests

被引：0
|
作者：
Wang W. [1 ,2 ]
Wang G. [1 ,2 ]
Liu C. [1 ,2 ]
Li J. [3 ]
机构：
[1] The Institute of Hydrogeology and Environmental Geology, CAGS, Shijiazhuang
[2] Technology Innovation Center of Geothermal & Hot Dry Rock Exploration and Development, Ministry of Natural Resources, Shijiazhuang
[3] Third Hydrological Engineering Geological Brigade, Hebei Bureau of Geology and Mineral Resources, Hengshui, 053000, Hebei
来源：
Dizhi Xuebao/Acta Geologica Sinica | 2020年 / 94卷 / 07期
关键词：
Effective thermal conductivity (λ[!sub]eff[!/sub]); Influencing factors; Lithology; Peclet number (Pe); Thermal response test (TRT);
D O I：
10.19762/j.cnki.dizhixuebao.2020212
中图分类号：
学科分类号：
摘要：
Average thermal parameters of the whole heat exchanger can be measured by in situ thermal response test (TRT). TRT can simulate the actual operation of the ground source heat pump (GSHP) and has been widely used in designing the GSHP. Data of TRTs from 89 different boreholes in China were collected and analyzed. Effective thermal conductivity (λeff) of the ground within 200 m was analyzed and its influencing factors were evaluated. Results show that thermal conductivity from TRT results are mostly between 1.50 and 2.16 W/(m•K) with cumulative probability between 25%~75%. Generally speaking, underground materials with coarse grain, high water yield and strong groundwater velocity show better heat transfer capacity. Lithology, water content and groundwater flow are import influencing factors for effective thermal conductivity. The regional variability of the underground material and groundwater level depth within 200m are important factors controlling effective thermal conductivity. Groundwater flow also plays an important role and the modified Peclet number (Pe) is introduced to define the effect of groundwater flow. When Pe is between 0.28 and 0.84, a 47% increase in Pe number results in a 7.56% increase in the effective thermal conductivity of the ground. © 2020, Science Press. All right reserved.
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页码：2089 / 2095
页数：6
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