含湿岩土间歇蓄/放热过程热物性动态演变机理研究

Under intermittent storage / exothermic process of moisture soil, the geotechnical.thermos–physical properties change complicatedly because of the step changes of.thermal parameters, which in turn influence heat transfer in underground rock. In.this project, the evolution mechanism of geotechnical thermos–physical dynamical.characteristic is depth explored through experiments and simulations. The thermo.physical properties and heat response characteristic due to variations inherent.relationship of two states moisture soil (saturated and unsaturated) were studied.under different conditions of intermittent storage / exothermic process by using.soil micro-source heat pump experiment system. Based on soil moisture dynamics.theory, the relationship between thermodynamic features and   thermophysical.property was simulation analyzed under the intermittent storage / exothermic.process. The influence of the soil evaporation condensation process on thermal.property is discussed and the mathematical model of the thermal properties of.moisture soil was build in features on the dynamic evolution of the step. The.evolution regular pattern of moisture soil thermal properties under intermittent.storage / exothermic process were clarified, based on which, using Monte Carlo.method, an mathematical model coupling geotechnical heat transfer with moisture.penetration will be established, the geotechnical thermos –physical properties.under the step changes of thermal parameters will be   clarified and which the.dynamic evolution mechanism will be revealed.

含湿岩土间歇蓄/放热过程中，受到阶跃变化的非平衡热力特征的影响，岩土热物性发生.复杂的动态演变，对地下传热传质产生影响。本项目通过实验研究和数值分析相结合的手段，.深入探索含湿岩土热物性的动态演变机理。利用微型土壤源热泵实验系统研究两种状态含湿土.壤（饱和、非饱和）的热物性在不同条件下间歇蓄/放热过程中的热响应特性及内在因变关系.；结合多孔介质理论与土壤水分动力学理论，数值分析两种状态土壤在间歇蓄/放热过程中变.化的热力特征与热物性之间的数学关系，探讨土壤蒸发冷凝过程对热物性的影响，建立含湿岩.土热物性在阶跃特征影响下动态演变的数学模型，阐明含湿岩土间歇蓄/放热过程中热物性的.动态演变规律，并在此基础上，利用蒙特卡洛数学方法建立岩土热物性—含湿岩土热渗耦合传.递的数学模型，分析预测含湿岩土间歇蓄/放热过程热物性的动态变化特性，揭示含湿岩土热.物性在间歇蓄/放热过程中的动态演变机理。

在土壤源热泵运行过程中，受到阶跃变化的非平衡热力特征的影响，岩土热物性发生复杂的动态演变，对地下传热传质产生影响。尤其是在存在地下水渗流的情况下，所表现出来的温变特性渗流特性及物性变化特性均不相同，即使同种类型土壤不同土质层的岩土热物性也会不同，且随着岩土的间歇蓄/放热过程发生非线性变化。本项目采用数值分析和实验研究相结合的手段，探究含湿岩土间歇蓄/放热过程中热物性的动态演变规律。利用LBM理论方法，建立岩土层流动换热模型，研究了吸热过程中岩土层土壤多孔介质内热湿耦合过程。重点研究了不同土壤孔隙率、壁面温度和壁面润湿性对于多孔介质内流场与温度场的影响。建立了微型土壤源热泵实验平台，分别对冬季、夏季两种工况下，多种工况下的土壤源热泵系统运行过程中的土壤导热系数变化进行实验研究。研究结果表明，土壤的热物性参数与土壤孔隙率、含湿率、系统运行工况等诸多因素相关，且这种影响会反作用于土壤的传热过程。