Study on thermophysical properties of silty clay in Guanzhong Basin, Shaanxi Province
XUE Shengze1,2, ZHOU Yang3,4, LIU Jianqiang3,4
1. College of Geology and Environment, Xi'an University of Science and Technology, Shaanxi Xi'an 710054, China; 2. Geological Research Institute for Coal Green Mining, Xi'an University of Science and Technology, Shaanxi Xi'an 710054, China; 3. Shaanxi Institute of Geological Survey, Shaanxi Xi'an 710054, China; 4. Shaanxi Hydrogeology Engineering Geology and Environmental Geology Survey Center, Shaanxi Xi'an 710068, China
Abstract：The shallow geothermal energy resources in Guanzhong Basin are very rich, but the exploitation degree still needs to be improved. The engineering characteristics of soil are determined by the thermophysical properties, which has a great impact on the basic theories and development methods during the development and utilization of shallow geothermal energy. Through the laboratory tests of thermophysical properties of silty clay in Xi'an, Xianyang, Weinan and Baoji, and the analysis of experimental data, the authors revealed the macroscopic variation rules of specific heat capacity, thermal diffusivity and thermal conductivity. The results show that, the thermal conductivity of silty clay is 0.82 to 2.65 W/(m·k), the thermal diffusivity is 0.001 28 to 0.004 86 m2/h, and the specific heat capacity is 0.77 to 1.53 kJ/(kg·K). With the increase of water content, the thermal conductivity shows a decrease trend, and its value range becomes narrow. The specific heat capacity decreases with the increase of thermal diffusivity in general. The thermal diffusivity increases linearly with thermal conductivity, and the correlation coefficients are all high. This research would provide some theoretical basis for the development of shallow geothermal energy in engineering practice process.
[1] 周阳,洪增林,张卉,等.关中盆地浅层地热能赋存规律及资源量估算[J].中国地质调查,2020,7(2):21-29. Zhou Y,Hong Z L,Zhang H,et al.Occurrence rules and resource estimation of shallow geothermal energy in Guanzhong Basin[J].Geol Surv China,2020,7(2):21-29. [2] Xing H,Di Y S,Yong Y.Analysis on the law of occurrence of shallow geothermal energy in Zhoukou City of Henan Province,China[J].J Groundwater Sci Eng,2019,7(3):282-287. [3] 王婉丽,王贵玲,朱喜,等.中国省会城市浅层地热能开发利用条件及潜力评价[J].中国地质,2017,44(6):1062-1073. Wang W L,Wang G L,Zhu X,et al.Characteristics and potential of shallow geothermal resources in provincial capital cities of China[J].Geol China,2017,44(6):1062-1073. [4] 王贵玲,刘彦广,朱喜,等.中国地热资源现状及发展趋势[J].地学前缘,2020,27(1):1-9. Wang G L,Liu Y G,Zhu X,et al.The status and development trend of geothermal resources in China[J].Earth Sci Front,2020,27(1):1-9. [5] 李修成,马致远,张雪莲,等.陕西省关中盆地东大地热田成因机制分析[J].中国地质,2016,43(6):2082-2091. Li X C,Ma Z Y,Zhang X L,et al.Genetic model of the Dongda geothermal field in Guanzhong Basin,Shaanxi Province[J].Geol China,2016,43(6):2082-2091. [6] 孙红丽. 关中盆地地热资源赋存特征及成因模式研究[D].北京:中国地质大学(北京),2015. Sun H L.The Bearing Features and Genetic Model for Geothermal Resources in Guanzhong Basin[D].Beijing:China University of Geosciences(Beijing),2015. [7] Wang J,Zhang X P,Du L Z.A laboratory study of the correlation between the thermal conductivity and electrical resistivity of soil[J].J Appl Geophys,2017,145:12-16. [8] 周阳,张卉,桂忠强,等.岩土体综合导热系数影响因素研究[J].中国地质调查,2018,5(1):89-94. Zhou Y,Zhang H,Gui Z Q,et al.Study on influencing factors of comprehensive thermal conductivity of rock and soil[J].Geol Surv China,2018,5(1):89-94. [9] 高志友,朱喜,张勇,等.济南市浅层岩土导热系数影响因素分析[J].山东科学,2019,32(3):103-112. Gao Z Y,Zhu X,Zhang Y,et al.Analysis of influencing factors on heat conductivities of shallow layer rock and soil in Jinan[J].Shandong Sci,2019,32(3):103-112. [10] Sun Q,Lyu C,Zhang W Q.The relationship between thermal conductivity and electrical resistivity of silty clay soil in the temperature range -20 ℃ to 10 ℃[J].Heat Mass Transf,2020,56(6):2007-2013. [11] Zhang N,Wang Z Y.Review of soil thermal conductivity and predictive models[J].Int J Therm Sci,2017,117:172-183. [12] 李婷,王全九,樊军.土壤热参数确定方法比较与修正[J].农业工程学报,2008,24(3):59-64. Li T,Wang Q J,Fan J.Modification and comparison of methods for determining soil thermal parameters[J].Trans CSAE,2008,24(3):59-64. [13] 王铁行,刘自成,卢靖.黄土导热系数和比热容的实验研究[J].岩土力学,2007,28(4):655-658. Wang T X,Liu Z C,Lu J.Experimental study on coefficient of thermal conductivity and specific volume heat of loess[J].Rock Soil Mech,2007,28(4):655-658. [14] 周媛媛,江海峰,李辉,等.含水砂土导热系数实验研究[J].工程热物理学报,2015,36(2):265-268. Zhou Y Y,Jiang H F,Li H,et al.Experimental study of the thermal conductivity of sand with different moisture content[J].J Eng Thermophys,2015,36(2):265-268. [15] Mostaghimi J,Pfender E.Measurement of thermal conductivities of soils[J].Wärme-Und Stoffübertragung,1980,13(1/2):3-9. [16] 栾英波,郑桂森,卫万顺.北京平原区粉质粘土热导率影响因素实验研究[J].中国地质,2013,40(3):981-988. Luan Y B,Zheng G S,Wei W S.The experimental study of the factors affecting the rate of thermal conductivity of silty clay in Beijing Plain[J].Geol China,2013,40(3):981-988.
2021, Vol. 8 
