| 摘要: |
| 随着航空航天领域的发展采用沸腾换热的高效换热技术越来越受到关注,泡沫金属具有比表面积大、导热系数高的优 点,可以强化流动沸腾换热的效果。本文在实验工况为孔密度10-40PPI,干度0.1-0.9,质流密度90-180kg/(m2·s),热流密度12.4-18.6kW/m2的条件下,研究了表面润湿性为未改性和疏水改性的泡沫金属管内制冷剂流动沸腾换热的情况。结果表 明:40PPI泡沫金属管比10PPI泡沫金属管的沸腾换热表面传热系数最多增大了96%;随着干度.质流密度和热流密度的增大，泡沫金属管内流动沸腾换热表面传热系数最多分别增大74%,95%以及48%；疏水改性增加了泡沫表面的成核点数,与未改性相 比可以使传热系数增大10%-30%。 |
| 关键词: 流动沸腾 泡沫金属 孔密度 换热 |
| DOI： |
| 投稿时间：2021-01-15 修订日期：2020-03-25
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| 基金项目:国家自然科学基金(51976115)资助项目；上海市科委科技创新行动计划(19142203000)项目资助。 |
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| Effect of Metal Foam Structure on Flow Boiling Heat Transfer Characteristics |
|
Hu Haitiao, lai Zhancheng, Zhao Yaxin, Li Mengshan
|
| (Institute of Refrigeration and Cryogenics，Shanghai Jiao 'Tong University) |
| Abstract: |
| With the development of aeronautics and astronautics, more and more attention has paid to efficient heat transfer inside a tube. Metal foam has a large specific surface area and high thermal conductivity, which are suitable for enhancing the flow boiling heat transfer. In this study, the effect of the metal foam structure on the flow boiling heat transfer in tubes was studied experimentally. The experimental conditions covered a pore density of 10–40 pores per inch (PPI), vapor quality of 0.1–0.9, mass flux of 90–180 kg/(m2·s), and a heat flux of 12.4–18.6 kW/m2, and the wettability of the hydrophobic or uncoated surfaces. The experimental results show that the heat transfer coefficient of the 40 PPI metal foam tube is up to 96% higher than that of the of the 10 PPI metal foam tube. With an increase in vapor quality, mass flux, and heat flux, the flow boiling heat transfer in the metal foam filled tube is increased by a maximum of 74%, 95%, and 48%, respectively, and hydrophobic modification increases the number of nucleate sites on the metal foam surface, resulting in a heat transfer enhancement of 10%–30%. |
| Key words: flow boiling metal foam pore density heat transfer |
