生成陽極氧化鋁奈米表面於重力熱管內熱傳性能之研究

Study on the heat transfer performance of gravity heat pipes with anodized aluminum oxide nano-surface

楊孟學(Meng-Hsueh Yang)

指導教授 ： 翁輝竹

中原大學/工學院/機械工程研究所/碩士(2017年)

https://doi.org/10.6840/cycu201700498

摘要

本論文完成生成陽極氧化鋁奈米表面於重力熱管內熱傳性能之研究，主要目的在實驗探討不同的熱輸入功率下，氧化鋁奈米管長與管徑對重力熱管溫度分布、熱阻與乾燒現象之影響。首先，運用陽極氧化法於鋁製重力熱管之蒸發端內壁表面生成陽極氧化鋁奈米管。接著，控制不同陽極氧化處理電壓與時間，以獲得不同奈米管長與管徑之氧化表面。進一步，利用FE-SEM觀察其生成結果。最後，將處理過後之重力熱管放置於散熱測試系統，以量測溫度、計算熱阻，並記錄乾燒現象。
結果發現，在特定熱輸入功率下，增加陽極氧化處理時間可生成長度較長之氧化鋁奈米管，重力熱管內蒸發端與冷凝端之溫度變化，以及其內表面熱阻隨著管長增長而下降，而管長的增長另可達到延後乾燒現象之發生；增加陽極氧化處理電壓可生成較大之奈米管徑，重力熱管內蒸發端與冷凝端之溫度變化，以及其內表面熱阻亦隨著管徑增大而下降，而管徑的增大似乎未對乾燒現象造成影響。綜上結果得知，若將陽極氧化處理應用於重力熱管蒸發端內壁表面，可明顯提升重力熱管之熱傳輸效果。並且，隨著處理時間與電壓的增長與增大，可進一步放大重力熱管內熱傳性能。

關鍵字

重力熱管；陽極氧化處理；氧化鋁奈米管；奈米結構效應

並列摘要

This thesis is conducted with the study on the heat transfer performance of gravity heat pipes with anodized aluminum oxide nano-surface. The main purpose is to experimentally investigate the influences of aluminum oxide nanotube length and diameter on the temperature distribution, thermal resistance, and dryout phenomenon of gravity heat pipes under different thermal powers input. First, the anodic oxidation method is used to generate anodic aluminum nanotubes on the inner wall-surface of the evaporation section of aluminum gravity heat pipes. Then, nano-surfaces with different nanotube lengths and diameters are obtained by controlling the anodic oxidation time and voltage. Further, the shape of those nanotubes are observed by using the FE-SEM. Finally, these gravity heat pipes are placed in a thermal test system so as to measure the temperature, calculate the thermal resistance, and record the dryout phenomenon.
The results show that the increase in the anodic oxidation time could increase the length of an anodized aluminum nanotube under a particular thermal power input. Increasing the nanotube length reduces the temperature change between the evaporation section and condensation section and the thermal resistance; moreover, the dryout phenomenon is delayed. In addition, the increase in the anodic oxidation voltage could increase the nanotube diameter. Increasing the nanotube diameter also reduces the temperature change between the evaporation section and condensation section and the thermal resistance; however, the increase in diameter does not seem to affect the dryout phenomenon. In summary, if the anodic oxidation treatment is applied to the inner wall surface of the evaporation section of a gravity heat pipe, the heat transfer performance could be obviously improved. The heat transfer performance of the gravity heat pipe could further be enhanced by increasing the anodic oxidation time and voltage.

並列關鍵字

gravity heat pipes ； anodic oxidation treatment ； aluminum oxide nanotubes ； nanostructure effects

參考文獻

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