Abstract:

Metal foam has very large specific surface area, and it has great potential in dehumidification. The key for designing metal foam heat exchanger for dehumidification is to promote the drainage performance of metal foam. The influence of structure factors on drainage performance of metal foam with three different surface wettability was investigated by dynamic dip test in this study. The results showed that, the drainage performance was deteriorated with the increase of pore density or height and promoted with the increase of porosity. For hydrophobic samples, the drainage performance of 5—40PPI metal foams was promoted, while water retention was reduced by 26%—60%. For hydrophilic samples, the drainage performance of 5—10PPI metal foam was promoted with the maximum reduction of water retention of 23%, while the drainage performance of 15—40PPI metal foam was deteriorated with the maximum increment of water retention of 13%.

Key words: dehumidification, metal foam, structure, drainage, porous media, flow

摘要：

泡沫金属具有超大比表面积，应用在除湿领域有很大潜力；保证泡沫金属表面冷凝液滴的及时排出是开发泡沫金属除湿换热器的关键，因此必须明确泡沫金属的排水性能。通过动态浸入实验，研究了3种不同润湿性下泡沫金属结构特性对排水性能的影响。研究结果表明：泡沫金属的孔密度越大，孔隙率越低，重力方向高度越大，排水性越差；疏水改性下5~40PPI泡沫金属的排水性能增强，残余水量减少26%~60%；亲水改性下5~10PPI泡沫金属的排水性能增强，残余水量最多降低23%，但15~40PPI泡沫金属的排水性能减弱，残余水量最多增大13%。

关键词: 除湿, 泡沫金属, 结构, 排水, 多孔介质, 流动