微观结构对膜换湿能力影响研究  

STUDIES OF THE EFFECTS OF MICROSTRUCTURE ON MOISTURE PENETRATION THROUGH MEMBRANES

作　　者：胡腾[1] 闵敬春[1] 宋耀祖[1] 

机构地区：[1]清华大学航空航天学院工程力学系,北京100084

出　　处：《工程热物理学报》2010年第2期307-310,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50576040)

摘　　要：对多孔膜换湿过程进行了理论分析,得到了透湿量和湿阻的计算式.同时对三种膜包括PVDF,PES和纤维素膜进行了湿阻的测量实验,通过对实验数据的回归处理,得到了多孔膜的结构参数.结果表明,膜厚、孔径分布、孔隙率及曲折因子对膜的换湿特性都有较大影响,在平均孔径相同的情况下,其它因素仍然导致了不同膜换湿能力的较大差距。在所获得的结构参数基础上,通过数值模拟的方法研究了平均孔径对膜换湿能力的影响。结果表明湿阻随平均孔径的增大而减小,减小趋势逐渐平缓最后趋向一定值。A theoretical study has been conducted to investigate the effects of microstructure on the transport properties of water vapor through membranes and a model to predict the moisture flux and moisture resistance was obtained.Experiments were made to measure the moisture resistances in three porous membranes including PVDF,PES and Cellulose membranes.Parameters on membrane structures were determined through regression of the experimental data.The results support that the membrane thickness,pore size distribution,effective porosity and tortuosity all have significant impacts on the moisture penetration through membranes.Based on the parameters,the effects of the mean pore size were studied numerically.The results show that：as the mean pore size increases,the moisture resistance decreases,but the decreasing rate becomes smaller for larger pore size.

关 键 词：膜换湿 多孔膜 微观结构 湿阻 

分 类 号：TK124[动力工程及工程热物理—工程热物理]