摘要
岩土体热导率是热物理性质重要参数之一,不仅仅决定着浅层地温场的展布形态,而且也是整个热泵功率计算的核心,是影响地源热泵工程投资和运行能耗的关键因素。本文通过一系列实验,对粉质粘土的热导率与含水量、密度、孔隙比进行研究和统计,从实验研究结果来看,粉质粘土热导率随着含水量的增大而增大,可以用对数关系和乘幂关系进行拟合,相关系数较好,由于样品物质成分和微观结构差异影响着传热方式组合,难以用统一的拟合方程表示同一地区热导率与含水量等因素变化规律。在含水率不变的情况下随着孔隙比的增大而热导率逐渐减小,随密度的增加而热导率增大的规律趋势明显。粉质粘土热导率随含水量的变化可分为3个阶段,含水量在0~5%,热导率随之增加急剧,含水量5%~20%时,热导率随之增加较快,含水量大于20%时,热导率随之增加缓慢并趋于稳定。
Being one of the most important parameters, the rate of thermal conductivity of rock and soil not only decides the distribution of the shallow geothermal field but also constitutes the core of the whole calculation of the heat pump power, thus serving as the key factor affecting the investment on ground-source heat pump projects and the operating energy consumption. Based on a series of experiments, the authors made a full study and statistic analysis of the relationship of the rate of thermal conductivity to water content, natural density and porosity. The test results show that the natural water content increases with the increase of the silty clay thermal conductivity, which can be fitted with the logarithmic and power relationship to obtain the better correlation coefficient. Because the differences in material compositions and microstructures of the samples affect the combination of the heat transfer, it is difficult to indicate the variation trend of the thermal conductivity and water content in the same area with the uniform fitting equations. With the increasing porosity, the rate of thermal conductivity decreases under the condition of constant water content. With the increasing density, the authors obtained the clear trend of increasing rate of thermal conductivity. There are three stages in the variation of rate of thermal conductivity and water content of silty clay. The rate of thermal conductivity increases dramatically when the water content varies in the range of 0-5%. The rate of thermal conductivity increases faster when the water content varies in the range of 5%-20%. The rate of thermal conductivity increases slowly and tends to stabilize when the water content is over 20%.
出处
《中国地质》
CAS
CSCD
北大核心
2013年第3期981-988,共8页
Geology in China
基金
北京市优秀人才培养资助计划(2010D00201100000)
北京平原区浅层地温能资源地质勘查项目(pxm2006-000-043289)资助
关键词
热导率
粉质粘土
统计分析
北京地区
rate of thermal conductivity
silty clay
statistical analysis
Beijing area