基于分形理论的耦合气固反应热质源的多孔介质热质传递研究

项目名称： 基于分形理论的耦合气固反应热质源的多孔介质热质传递研究

项目编号： No.51306023

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 能源与动力工程

项目作者： 汪城

作者单位： 常州大学

项目金额： 25万元

中文摘要： 气固反应系统中的膨胀石墨压块基材复合反应材料是一种典型的多孔介质，热质传递性能是其重要的性能参数。由于孔隙结构复杂，传热、传质和反应过程三者相互耦合，较难确定导热系数和气体渗透率，尤其是在反应过程中的变化规律。本项目将利用CT扫描技术，依据分形理论建立孔隙结构模型，通过扫描电镜和光学显微镜多尺度、多维度观察，结合图形处理技术、统计学原理和分形理论，确定孔隙结构参数和分形维数；其次，依据热质传递理论、反应动力学和热力学理论，建立传热、传质和反应模型，结合分形孔隙结构模型，理论分析多孔介质在气固反应过程中的结构改变和热质传递性能的变化；完善现有传热传质性能测试平台，对伴随气固反应过程的多孔介质导热系数和气体渗透率进行实验测量，建立数据库，验证和修正理论模型；最后，分析气固反应系统性能，优化材料的制备工艺和结构参数。通过本项目的实施，还将为相关多孔介质的复杂传热传质问题研究提供有一种可行的方法。

中文关键词： 多孔介质；传热传质；分形；火积；熵

英文摘要： Composite reactive material based on expanded graphite matrix is a typical kind of porous media used in solid-gas reaction system. The heat and mass transfer performances are important index parameters. Due to the complex porous structure and the coupled processes of heat transfer, mass transfer and solid-gas reaction, it was hard to measure the thermal conductivity and gas permeability of the porous media, especially their variations caused by solid-gas reaction. In this project, it was proposed to observe the complex porous structure and establish the model of porous media based on fractal theory, to theoretically investigate the heat and mass transfer performances based on the study of the processes the porous media experienced, i.e. heat transfer process, mass tranfer process and solid-gas reaction, and to experimentally measure the parameters with specially designed test-rigs. The porous media was CT-scanned. The fractal dimensions involved in the model of porous media were determined by observation with SEM and optical microscope, followed by graphic processing and mathematical analysis. The theoretical models of thermal conductivity and gas permeability of porous media in the process of solid-gas reaction were also established. The heat and mass transfer performances were determined from the fractal model

英文关键词： porous media；heat mass transfer；fractal；entransy；entropy