气凝胶纳米多孔材料传热计算模型研究进展  

A review of heat transfer models of nanoporous silica aerogel insulation material

作　　者：何雅玲[1] 谢涛[1] 

机构地区：[1]西安交通大学能源与动力工程学院,热流科学与工程教育部重点实验室,西安710049

出　　处：《科学通报》2015年第2期137-163,共27页Chinese Science Bulletin

基　　金：国家自然科学基金重点项目(51436007);国家重点基础研究发展计划(2013CB228304)资助

摘　　要：对新型气凝胶纳米多孔隔热材料等效热导率计算模型在近年来的发展进行了研究总结,介绍了(1)纳米尺度下气凝胶隔热材料的气相/固相/辐射等不同传热模式的传热特点;(2)气凝胶纳米尺度多孔网络中的气相传热、固相传热以及辐射传热的理论计算、数值预测以及经验关联等不同计算模型的特点及建立方法;(3)气凝胶纳米多孔隔热材料以及气凝胶复合隔热材料的整体等效热导率计算模型的研究进展;(4)以前期开展的研究工作为例,具体说明了气凝胶复合隔热材料从纳米尺度到微米尺度的传热模型的建立过程以及整体等效热导率计算模型的建立方法;(5)对分子动力学方法在气凝胶纳米多孔材料中的应用做了简要介绍.最后指出,对于气凝胶纳米多孔材料,其纳米尺度下的气固接触界面等特殊区域的耦合传热机理研究还不完善,复杂结构的纳米颗粒的固相热导率以及整体热导率计算模型也不够准确.因而采取适用于纳米尺度下的传热计算方法对这些问题进行更细致深入的研究,可以为进一步阐明气凝胶复合隔热材料内部的热量传递机理,建立更准确的气凝胶复合隔热材料传热计算模型,探索不同影响因素对传热性能的影响规律,以及开展气凝胶复合隔热材料的性能预测及优化等方面的研究,提供理论指导帮助.In this paper, the development of effective thermal conductivity models for nanoporous silica aerogel insulation materials is summarized. In the first part, heat transfer characteristics of nanoscale gaseous/solid/radiative heat transfer inside aerogel insulation material are introduced. Then, the existing theoretical models, empirical models, and numerical methods for the thermal conductivity of each heat transfer mode are reviewed and analyzed. After that, the advances in effective thermal conductivity models for the nanoporous silica aerogel materials as well as their composite insulation materials after the addition of opacifiers and reinforced fibers are presented. Next, the authors＇ previous work is taken as an illustration of a procedure for establishing an effective thermal conductivity model of an aerogel insulation material from nano- to macro-scale. A brief introduction to the application of molecular dynamics in the simulation of aerogel materials is also given. In the end, further researchneeds are indicatedfor the nanoporous silica aerogel insulation materials. These include： the coupled heat transfer behavior at the gas-solid contact interface, the influence of scale/interfacial effects on the thermal conductivity of nanoscale solid particles, and the effect of different influencing factors on the total heat transfer performance. Such studies could provide help in accurately predicting the thermal conductivity as well as optimizing the insulation performance for the aerogel material and could provide guide for the design of new type aerogel insulation material which can be used in industry such as aeronautics and astronautics, thermal insulation, building, chemical industry and so on.

关 键 词：气凝胶纳米多孔材料 等效热导率 气相传热 固相传热 辐射传热 

分 类 号：TB383.4[一般工业技术—材料科学与工程] TK124[动力工程及工程热物理—工程热物理]