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Study on the evaluation method of heat transfer characteristics of rocks with cracks for the development of the deep ground.

深部发育裂隙岩石传热特性评价方法研究

基本信息

批准号：
08455215
负责人：
YANAGISAWA Eiji
金额：
$ 3.71万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455215/
关键词：
Porous Medium Heat transfer phenomenon Finite Element Method Transient heat flow Heat convection Soil properties Thermal properties of soils Nonlinear heat transfer 非定常熱伝導問題熱映像解析地盤材料等価介在物法

项目摘要

A personal computer system and a program to capture thermographs was developed for the analyses of laboratory experiment of the heat flow in the ground and then the heat transfer in the porous media saturated by pore water was examined using a small model ground. In this experimental equipment the ground with different permeability can be constructed and any amount of ground water flow can be given by changing the water head. A FEM program was also developed to analyze the experimental results and to evaluate the thermal constants of the constituents. Comparing the theoretical results and experimental ones, effect of water flow to the apparent heat conductivity of soil was studied, and it was found that there are strong effect of convection of heat by pore water on the heat conductivity of soil as a whole and an empirical equation proposed by De Vries gives an accurate values of heat conductivity of the soils.Application of percolation theory and equivalent inclusion method to the estimation of thermal constants of soils were examined last year and it was already concluded that these theories are not always convenient to evaluate the thermal constants of soils because the theoretical estimation always contains errors caused by assumption of structures and averaging procedures. In addition to that it was found that the proposed method of FEM calculation gives enough accurate results compared to the values estimated from these two theoretical assumptions. Therefore analytical studies by use of percolation theory and equivalent inclusion method was excluded from the studies of this year.

本文介绍了一个用于地下热流实验分析的微机系统和一个热像采集程序，并利用一个小型模型地下对孔隙水饱和多孔介质的传热进行了研究。该实验装置可以构造不同渗透性的地基，通过改变水头，可以给出任意量的地下水流量。还开发了一个有限元程序来分析实验结果，并评估组分的热常数。将理论计算结果与实验结果进行对比，研究了水流对土壤表观导热系数的影响，本文应用渗流理论和等效包体法对土壤的导热系数进行了估算，结果表明，孔隙水的热对流对土壤的导热系数有很强的影响，De弗里斯提出的经验公式能给出土壤导热系数的精确值土壤热常数的理论计算方法在去年进行了研究，并得出结论，这些理论并不总是方便地计算土壤的热常数，因为理论估计总是包含由结构假设和平均程序引起的误差。除此之外，还发现，与从这两个理论假设估计的值相比，所提出的有限元计算方法给出了足够准确的结果。因此，利用渗流理论和等效包合法进行的分析研究被排除在今年的研究之外。