辽宁省主要城市浅层地温能赋存条件及特征

Conditions and Features of the Occurrence of Shallow Geothermal Energy in Major Cities of Liaoning Province

摘要:

为研究岩土体的热物理参数变化规律等浅层地温能赋存特征，运用现场热响应试验和实验室测试分析等研究手段对岩土体导热系数（热导率）、孔隙度、比热容等参数进行科学分析，利用IGSHPA线热源模型和INGERSOll圆柱热源模型开展导热系数变化特征分析.研究结果显示，区内地层平均导热系数为1.68～3.44 W?（m?K）-1，高值区位于基岩山区.地层初始地温范围为10.80～15.80℃，高值区位于东、西两侧基岩山区及山前地带.在天然含水率条件下，岩土体的导热系数随含水率、颗粒密度、孔隙度的变化规律趋势明显，即随含水量的增大而逐渐减小，随颗粒密度的增加而增大，随孔隙度的增加而逐渐降低.随钻孔直径的增加，钻孔导热系数减小，钻孔热阻明显增加.以与初始地温差1.0°作为地温恢复的标准，黏性土地层恢复期需要5 d，中粗砂地层恢复期为3 d；以与初始地温差0.5°作为地温恢复的标准，黏性土地层恢复期需要15 d，中粗砂地层恢复期为7 d.

关键词:浅层地温能; 初始地温; 导热系数; 比热容; 线热源模型

Abstract:

Change rule for the study of the thermal physical parameters of rock and soil mass can occurrence characteristics of shallow ground temperature,such as using the thermal response test and the research methods such as laboratory test and analysis of geotechnical engineering (thermal conductivity),porosity,thermal conductivity,specific heat,scientific analysis,parameters,such as using IGSHPA line heat source model and INGERSOll cylindrical heat source model to carry out the analysis of characteristics of coefficient of thermal conductivity changes.The results show that the average thermal conductivity of strata in the area is 1.68～3.44W? (m?K)-1,and the high value area is located in bedrock mountainous area.Formation of initial ground temperature range of 10.80～15.80℃,the high value area in east and west on both sides of bedrock mountains and piedmont zone.Under the condition of natural moisture content,the thermal conductivity of the rock and soil body shows an obvious trend with the change of water content,particle density and porosity,that is,it gradually decreases with the increase of water content,increases with the increase of particle density and gradually decreases with the increase of porosity.As the diameter of borehole increases, the thermal conductivity of borehole decreases and the thermal resistance of borehole increases obviously.And the initial temperature of 1.0°as a standard for geothermal recovery,sticky soil layer recovery needs 5d,coarse sand formation in the recovery of 3d; And the initial temperature of 0.5°as a standard for geothermal recovery,sticky soil layer recovery need 15d,coarse sand formation in the recovery period for 7d.

Key words:shallow geothermal energy; initial ground temperature; heat conductivity coefficient; specific heat; line heat source model