变密度多孔介质强化导热模型及实验研究  

Model for the Enhanced Heat Conduction of a Variable Density Porous Medium and Its Experimental Study

作　　者：杨丽红[1] 孙金祥[1] 沈航明 

机构地区：[1]上海理工大学机械工程学院,上海200093

出　　处：《热能动力工程》2014年第5期515-520,595,共6页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金资助项目(51245009);上海市自然科学基金资助项目(12ZR1420600)

摘　　要：以等温容器截面为研究对象,基于多孔介质模型,采用变密度填充容器,强化中心向容器壁的导热。首先,基于稳态导热最小化热阻模型,确定了变密度铜丝2层和3层填充方案。其次,按确定的分层填充方案搭建实验台并测定容器有效导热系数,与均匀填充相比,导热系数分别增大了52.9%和77.9%。最后,对变密度填充下的瞬态导热进行了数值模拟研究,在中心温度200℃和中心热功率恒定两种情况下,经过一定时间热传导,变密度填充缩小了容器中心到容器壁的温度差。以上研究结果表明基于最小热阻的分层变密度填充铜丝可以强化由中心向周围的导热。With the section of an isothermal vessel serving as the object of study,based on the model for porous media,the vessel was filled at a variable density to enhance the heat conduction from the center to the wall of the vessel. Firstly,based on a model for the minimized heat resistance of the heat conduction in the steady state,the two-layer and three-layer copper wire filling scheme at a variable density were determined. Secondly,a test rig was set up according to the layered filling scheme and the effective heat conduction coefficient of the vessel was determined. Compared with the uniform filling scheme,the heat conduction coefficient increased by 52. 9% and 77. 9% respectively. Finally,a numerical simulation study was performed of the transient heat conduction under the condition of the vessel being filled at a variable density. Under the condition of the central temperature being 200 ℃ and the central thermal power being constant,through the heat conduction for a certain time period,the filling at a variable density minimized the temperature difference between the center and wall of the vessel. The foregoing research results show that based on the minimized heat resistance,layered filling with copper wires at a variable density can enhance the heat conduction from the center to its surroundings.

关 键 词：等温容器 多孔介质 变密度 强化导热 有效导热系数 

分 类 号：TK124[动力工程及工程热物理—工程热物理]