本研究以銅管製作具有環狀陣列的溝槽毛細結構之密閉二相虹吸式熱管，虹吸熱管整體高度為93.85mm，而內部溝槽毛細結構是以放電線切割加工法在25.4mm(OD)×19.4mm(ID)×82mm(L)的銅管內，切割出溝槽寬0.4mm、深2.4mm、溝槽數80個的矩形溝槽，提供裝置所需之毛細作用力。再以銅銀焊將管體與其他零件焊接組裝成型。 本研究之密閉二相虹吸式熱管之測試方法，是在熱管管體上裝置一散熱鰭片，於熱管上方裝置一風扇，利用強制空冷的方式帶走熱量，測試之加熱平台與本研究裝置接觸之加熱面積為31mm×31mm，施加13.5kgf之壓力，透過溫度點的量測，可推算加熱面之溫度，熱傳量與整體熱阻，並透過分析與計算，可定義並比較虹吸式熱管之性能。虹吸熱管採用去離子純水（D.I.water）當作其工作流體，並充填10.5%、18.2%、29.7%三種比例之工作流體，電源供應器輸出功率從20W開始，實驗達穩態後步級一個瓦數（20W），每次步級時間約一小時，其實驗結果顯示，發現充填率18.2%時，最高加熱功率可至160W，經計算後實際熱傳量高達140W，而加熱表面溫度維持在80℃以下，並可獲得本研究之最佳熱阻0.35℃/watt，此充填率相較於另外兩種充填率有較佳之效果，因此18.2 %為本研究虹吸式熱管之最佳充填率，並且提升整體散熱器的散熱效率。 In this study, a two-phase closed thermosyphon was fabricated with annular array grooved wicks by copper. The thermosyphon consisted of a 82mm long cooper tube having an inside diameter of 19.4mm and outside diameter of 25.4mm. Rectangular grooves with 0.4mm width and 2.4mm deep were cut by WEDM inside the tube to provide device wick capillary. The tube was sealed with other components by copper-silver welding. Thermal performance of the thermosyphon was evaluated experimentally in a fan-heat sink CPU test apparatus with a heating area of 31mm×31mm. the clamping pressure between the thermosyphon and the heat sink was maintained at 13.5 kgf during the test. The influence of working fluid filling ratio and heat load are studied. D.I. water was used as the working fluid and three different filling ratio,10.5%, 18.2% and 29.7% were investigated in the research. After evaluation, the thermosyphon with 18.2% fill rate showed the best performance compared to the other samples. It had a evaporator temperature at 80℃, corresponding to a thermal resistance of 0.35℃/watt at an actual input power of 140W.
