陳瑤明臺灣大學：機械工程學研究所王彥勛Wang, Yang-HsinYang-HsinWang2007-11-282018-06-282007-11-282018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/60961本研究的主要目的在於探討雙孔徑毛細結構(biporous wick)內不同的孔徑分佈 對迴路式熱管性能(LHP)之影響效應。實驗過程中改變孔洞成型劑的粒徑與含量來 調控毛細結構內的雙孔徑分佈曲線，並利用統計方法分析雙孔徑毛細結構的性能 測試結果，以取得2階因子間兩項變數的統計經驗模型(孔洞成型劑的大小： 48~62μm與74~88μm Na2CO3、孔洞成型劑的含量：20vol%與25vol%)，藉此找出較 佳的雙孔徑分佈曲線型態。最後，再進一步與單孔徑毛細結構(monoporous wick) 做熱傳量的比較。 研究結果顯示：目前實際製作結果獲得較佳的雙孔徑毛細結構，似乎傾向於 孔洞成型劑含量多(25vol%)且較小粒徑(48~62μm)的方向。其中又以改變孔洞成型 劑的含量(貢獻百分比B＝80%)對結果的影響最為明顯。在熱沉10℃與容許溫度 85℃下，較佳的雙孔徑毛細結構其熱傳量可達350W且熱阻為0.19℃/W，較單孔徑 毛細結構的熱傳性能300W與熱阻為0.23℃/W來得佳。不僅能擁有較高的熱傳量， 且能有效的降低熱阻，對於未來高熱通量的諸多應用場合是相當引人注目的。The purpose of this study was to investigate the effects of various pore size distributions of biporous wicks for a Loop heat pipe (LHP). The study was conducted following a statistical method using a two-level factorial plan involving three variables (particle size of pore former：48~62μm and 74~88μm Na2CO3, pore former content： 20vol% and 25vol%). Finally, a comparison was made between monoporous wicks and biporous wicks for the heat transport capability of the LHP. Experimental results showed that the better parameters of the biporous wick seem to tend to more pore former contents (25vol%), and smaller particle size of pore former (48~62μm), in particular pore former content (percent contribution B＝80%). At the sink 10 ℃ and the allowable evaporator temperature 85℃, the heat transfer capacity of the better biporous wick achieved 350W and the thermal resistance was 0.19 /W ℃ . In comparison to a monoporous wick for 300W and 0.23 /W, the performance is ℃ enhanced. LHPs with biporous wicks are very attractive for high heat flux applications in the future.中文摘要 ........................................................................................................................ i 英文摘要 ....................................................................................................................... ii 目錄 ..............................................................................................................................iii 圖目錄 ........................................................................................................................... v 表目錄 .......................................................................................................................... vi 符號說明 ..................................................................................................................... vii 第一章 緒論 ................................................................................................................. 1 1.1 前言 ................................................................................................................. 1 1.2 文獻回顧 ......................................................................................................... 5 1.3 研究目的 ......................................................................................................... 8 第二章 實驗原理及理論分析 ..................................................................................... 9 2.1 迴路式熱管操作原理 ..................................................................................... 9 2.1.1 毛細限制 ............................................................................................ 11 2.1.2 啟動限制 ............................................................................................ 11 2.1.3 液體過冷度限制 ................................................................................ 12 2.2 壓降理論分析 ............................................................................................... 12 2.2.1 液－汽介面之毛細壓差 .................................................................... 12 2.2.2 蒸發器溝槽內蒸汽流動壓降 ............................................................ 13 2.2.3 汽體段流動壓降 ................................................................................ 14 2.2.4 流經毛細結構之壓降 ........................................................................ 15 2.2.5 液體段及冷凝段流動壓降 ................................................................ 16 2.2.6 重力壓降 ............................................................................................ 17 2.3 補償室體積與工質注入量 ........................................................................... 18 2.3.1 補償室體積 ........................................................................................ 18 2.3.2 工質注入量 ........................................................................................ 18 第三章 實驗設備與毛細結構的製造方法 ............................................................... 20 3.1 實驗設備 ....................................................................................................... 20 3.1.1 實驗材料 ............................................................................................ 20 3.1.2 製造設備 ............................................................................................ 21 3.1.3 測試設備 ............................................................................................ 22 3.2 毛細結構的製造 ........................................................................................... 23 3.2.1 不同種類的雙孔徑毛細結構 ............................................................ 23 iv 3.2.2 雙孔徑毛細結構的製造方法 ............................................................ 24 3.2.3 毛細結構的主要參數 ........................................................................ 25 3.2.2.1 有效毛細半徑的量測 ............................................................... 25 3.2.2.2 孔隙度的量測 ........................................................................... 26 3.2.2.3 滲透度的量測 .................................................................... 26 3.3 迴路式熱管的熱性能測試 ........................................................................... 26 3.4 誤差分析 ....................................................................................................... 27 3.5 實驗參數 ....................................................................................................... 28 第四章 實驗設計方法 ............................................................................................... 29 4.1 二水準因子法 ............................................................................................... 29 4.1.1 因子的選擇 ........................................................................................ 29 4.1.2 自由度 ................................................................................................ 30 4.2 反應曲面法 ................................................................................................... 30 4.2.1 變異數分析 ........................................................................................ 30 4.3 雙孔徑毛細結構的因子選擇與範圍 ........................................................... 32 4.3.1 設計因子的選擇 ................................................................................ 32 4.3.2 設計因子的範圍 ................................................................................ 33 4.4 雙孔徑毛細結構的22 因子設計 .................................................................. 34 第五章 結果與討論 ................................................................................................... 36 5.1 蒸發器熱傳能力的反應曲面分析 ............................................................... 36 5.1.1 效應估計 ............................................................................................ 36 5.1.2 變異數分析 ........................................................................................ 37 5.1.3 蒸發器熱傳能力的反應曲面 ............................................................ 37 5.2 毛細結構內的孔徑分佈與熱傳能力之關係 ............................................... 39 5.2.1 單孔徑與雙孔徑毛細結構的熱傳能力比較 .................................... 39 5.2.2 單孔徑與雙孔徑毛細結構的孔徑分佈比較 .................................... 42 第六章 結論 ............................................................................................................... 44 6.1 結論 ............................................................................................................... 44 6.2 建議 ............................................................................................................... 45 參考文獻 ..................................................................................................................... 46 附錄A .......................................................................................................................... 49 附錄B .......................................................................................................................... 53 附錄C ................................................................................................................. 552304122 bytesapplication/pdfen-US孔徑分佈雙孔徑毛細結構迴路式熱管單孔徑毛細結構熱傳性能pore size distributionbiporous wickLoop heat pipemonoporous wickheat transport capabilitythesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/60961/1/ntu-96-R92522314-1.pdf