交錯潤濕性表面對冷凝熱傳之增強

本研究欲探討以超疏水為基底之交錯濕潤性表面,對含有空氣之水蒸氣冷凝熱傳之影響。分別在水平向下及垂直的冷凝面,進行不同改質條紋配置之實驗。實驗結果顯示,表面條紋配置、表面方向、表面過冷度,以及不可凝結氣體均會對冷凝熱傳產生影響。交錯濕潤性表面在水平及垂直時,分別呈現相反的熱傳趨勢。對水平冷凝面而言,改質條紋越寬,會有越好的熱傳增強效果;反之,改質條紋較細的交錯濕潤性表面,在表面垂直時熱傳效果較佳。此外,交錯濕潤性表面有助於擾動由不可凝結氣體產生之邊界層,進一步提升熱傳,且此效益在冷凝面沒有重力滑落效應,也就是水平時,更為顯著。此研究顯示,若是能仔細考量及設計表面條紋的配置及其他操作條件,交錯濕潤性表面的冷凝熱傳性能將能進一步提升。

關鍵字

冷凝熱傳；表面改質；交錯濕潤性

並列摘要

This study investigated the effect of surfaces with superhydrophobicity-based interlaced wettability on steam–air mixture condensation. Experiments were conducted on various types of surface with different modified strip widths under downward-facing horizontal and vertical surface orientations. The experimental results revealed that the condensation heat-transfer on surfaces with interlaced wettability could be highly influenced by the surface pattern, surface orientation, wall subcooling, and the existence of NCGs. Opposite trends of heat transfer were observed under different surface orientation. The experimental data of horizontal surfaces showed that the heat transfer can be enhanced when the width of the modified surperhydrophobic strips getting wider, while the narrower modified strips would increase the heat transfer more efficiently for vertical surfaces. In addition, a two-dimensional disturbance of the boundary layer imposed by NCGs is proposed, holding the potential to further heat transfer enhancement for steam-air condensation, especially in the situation without the sweeping of condensates under the gravity force. Such the facts imply that the potential of the interlaced surface could be further improved and applied if considering both the surface pattern and the operating conditions carefully.

並列關鍵字

condensation heat transfer ； surface modification ； interlaced wettability

參考文獻

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國際替代計量

交錯潤濕性表面對冷凝熱傳之增強

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