【作者】 支浩；

【导师】 奚正平； 汤慧萍；

【作者基本信息】 西安建筑科技大学 ， 材料学， 2009， 硕士

【摘要】 传热是我们生活中一种普遍现象,是现代工业中各个领域面临的共性问题。随着世界经济的快速发展,常规能源不断减少,人们在开发新能源的同时更加注重了节约能源的研究。强化传热是一种新近发展起来的高效传热技术,具有较高的传热效率,已成为传热研究领域的一个重要课题。在强化传热技术中,强化换热材料是强化传热领域的一个重要方面。在强化换热材料中,金属纤维以其独特的优势成为一种具有很好发展前途的换热材料。现如今金属多孔表面大多采用火焰喷涂法、机械加工法、复合法、粉末烧结法以及有序丝网烧结法制备,金属纤维多孔材料用于强化传热是传热学领域一个重要的研究方向,对于烧结金属纤维法制备传热用金属多孔材料的研究还很少。本文采用烧结法制备不同参数的传热用金属纤维多孔材料,重点研究了不锈钢和紫铜两种金属纤维多孔材料不同的制备工艺,探索出两种材料最佳烧结温度。通过实验摸索出一整套从原材料→铺制→烧结→修整→成品适合金属纤维多孔材料的制备工艺。用此方法制备的金属纤维多孔材料表面无污染,纤维之间结合紧密,材料内部孔隙结构均匀。本论文重点研究了材质以及结构参数对金属纤维多孔材料池沸腾传热性能的影响。结果表明,制备的金属纤维多孔材料具备较高的传热性能,传热效果与光表面比最大可提高6倍;金属纤维多孔材料在常压下的传热性能并不随纤维丝径和材料厚度的变化呈递增或递减;在孔隙率为80～90%的高孔隙率下,金属纤维多孔材料的传热性能随着孔隙率的降低而增强,80%的传热效果最好。本论文对于高效换热器的研究与开发具有重要的参考价值。更多还原

【Abstract】 Thermal transmission is a general phenomenon in our life and a similarity faced by the modern industries. Nowadays, with world economy growing rapidly, the conventional energy is decreasing at the same time. People should pay more attention on the research of energy conservation, while exploiting new energy resources. So that the technology of enhanced heat transfer appears at this time, and become an important subject in the heat-transfer research field. Material is one of most important aspect of enhanced heat transfer. Among all the enhanced heat transfer materials, metal fiber porous materials is one of the best potential heat-transfer materials because of its unique advantages.There are many methods for fabrication metal porous coatings, such as machining, sintering or brazing of particles, electrolytic deposition, flame spraying and ordered wire mesh structures. Heat transfer metal fibre porous materials is one of the important research directions in the field of enhanced heat transfer. But the research on metal fibre porous materials which is prepared by sintered metal fiber has not be extensivly concerned.In this thesis, the heat transfer metal fiber porous materials of stainless steel and copper fiber were prepared by sintering process whose procedure is as follow: fiber→cutting→paving→sintering→trimming→products. The optimal sintering temperatures changed with the fiber diameter. For dissimilar materials, the sintering temperatures were also different. The Scanning Electron Microscopy was show that the materials fabricated present symmetrical interpretation pore structures with randomly stacked fibers and high specific surface. The effects of material type and structure on the behavior of pool boiling heat transfer were experimentally studied. The experiment results showed that the porous materials present excellent heat transfer performance, the heat transfer coefficient of sintered copper fiber materials is about seven times higher than plain surface. The results also showed that : In the condition of atmospheric pressur, the transfer properties of the metal fibre porous materials did not depend on the biber diameter and thickness of the samples.In the range of 80-90%, with the decrease of porositys, the heat transfer increases. When the porosity was 80%, the heat transfer property reached to the maximum.The result of this thesis is valuable for the research and exploitation of highly active heat-change facilities.The research of this dissertation is funded by National "973" Project (project No.2006CB601200)更多还原