针对高分子材料的换热器普遍存在传热系数低的问题，提出了基于毛细润湿机理的PVDF中空纤维换热毛细管。首先采用非溶剂致相分离法制备具有多孔结构的PVDF中空纤维换热毛细管，利用换热毛细管壁中的非贯通孔在换热过程中，空气隙被水填充后，微孔中的水分受传热过程中管壁两侧温差而产生微循环，可增强传热从而提高传热系数，还对换热毛细管的力学性能、孔隙率、表面结构、断面结构等方面进行表征，揭示换热管表面微孔对传热的促进机理。亲水化改性后的总传热系数比改性前可提升104％。
The heat exchangers of polymer material have the problem of low thermal conductivity.This paper proposes PVDF heat exchange capillary tubes based on capillary wetting mechanism.Namely PVDF heat ex-change capillary tubes with porous structure were prepared by nonsolvent induce phase separation,the heat transfer process was intensified by wetting the air gap of the capillary surface,and their mechanical perform-ance,internal porosity and structure were characterized.It is shown that heat transfer has been promoted by the air gap of the capillary surface.However,thermal transmission is hindered by the air gap of the capillary surface for the low conductivity of air.The air gap of the micropores in the tube wall would be filled up with water after the micropores of the tubes wall being hydrophilized which means that water in the micropores would form mi-cro-convection by the temperature difference between two sides of the tube wall.Thus the heat transfer coeffi-cient could be significantly improved.The total heat transfer coefficient of hollow fiber heat exchanger can be improved of 104% after being hydrophilized.
参考文献
| [1] | 于开录;吕庆春;阮国岭.低温多效蒸馏海水淡化工程与技术进展[J].中国给水排水,2008(22):82-85. |
| [2] | N. Lukic;L.L. Diezel;A.P. Froba.Economical aspects of the improvement of a mechanical vapour compression desalination plant by dropwise condensation[J].Desalination: The International Journal on the Science and Technology of Desalting and Water Purification,20101/2(1/2):173-178. |
| [3] | Jochen B.P. Christmann;Lorenz J. Kratz;Hans-Jorg Bart.Falling film evaporation with polymeric heat transfer surfaces[J].Desalination: The International Journal on the Science and Technology of Desalting and Water Purification,2013:56-62. |
| [4] | L. Zaheed;R. J. J. Jachuck.Review of polymer compact heat exchangers, with special emphasis on a polymer film unit[J].Applied thermal engineering: Design, processes, equipment, economics,200416(16):2323-2358. |
| [5] | Lin Chen;Zhen Li;Zeng-Yuan Guo.Experimental investigation of plastic finned-tube heat exchangers, with emphasis on material thermal conductivity[J].Experimental Thermal and Fluid Science: International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics,20095(5):922-928. |
| [6] | 张春燕;于俊荣;刘兆峰.中空纤维制备技术及其应用[J].合成纤维,2004(6):21-24. |
| [7] | 衣卫京;肖红.中空纤维的技术现状和发展展望[J].合成纤维,2004(z1):15-17,20. |
| [8] | 吕晓龙.中空纤维多孔膜性能评价方法探讨[J].膜科学与技术,2011(02):1-6. |
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