陳瑤明臺灣大學：機械工程學研究所陳柏綸Chen, Po-LunPo-LunChen2007-11-282018-06-282007-11-282018-06-282005http://ntur.lib.ntu.edu.tw//handle/246246/61513本文旨在運用雙孔徑毛細結構增強迴路式熱管之熱傳性能。文中採用兩種不同粒徑的同種粉末，實際製造出具備兩種孔徑毛細結構，包括雙層型及混粉型。藉以增加更多而有效之蒸氣產生區域進而提昇整體迴路式熱管之性能。文中並同時製作出單孔徑毛細結構以利比較，最後將其分別置入迴路式熱管系統中，測試其性能表現，包括其熱傳能力和熱阻。 在毛細結構製作上，燒結程序中，歷經繁覆的試驗程序，找出各不同粉徑毛細結構與燒結成形溫度的關係，據此並獲得雙孔徑燒結的最佳燒結建議，成功製作完成雙孔徑毛細結構。在毛細結構的性能上，孔隙度在相近的狀態下，雙粉燒結之1:1混粉型式滲透度比單孔徑毛細結構可提升約30%。 綜整實驗結果，比較單粉鬆裝燒結和選用雙粉鬆裝燒結所製作出來的雙孔徑毛細結構之熱性能測試。發現此兩種型式之雙孔徑毛細結構在高瓦數時，達到穩態的時間較單孔徑毛細結構為短，顯示雙孔徑毛細結構較單孔徑毛細結構擁有較佳的液汽分布以便能快速地達到穩態。在同樣設定操作溫度80℃下，單孔徑毛細結構表現出之最佳性能為200W，熱阻為0.26℃/W；選用雙粉鬆裝燒結所製作出的毛細結構，在混粉型式重量比例達1：1時，可達到最大瓦數為300W，熱阻為0.17℃/W。初步量測結果顯示，具雙孔徑毛細結構之迴路式熱管在熱傳性能的提升方面，頗有相當之潛力。In this paper, bidisperse wick structures were manufactured for enhancing the heat transfer capabilities of the loop heat pipe. Use two particle sizes of the same material to manufacture two types of the bidisperse wick structures, called “the two layers” and “the powders mixed” for increasing more effective vapor region to promote the performance of the loop heat pipe. In the meanwhile, the monodisperse wick structure is manufactured for a contrast. Both of the monodisperse and the bidisperse wick structures were then installed into the loop heat pipe, then the heat transfer performance of the loop heat pipe system was tested. Find the relationship among the different particle sizes with the temperature of the forming wick structures by many times of sintering experiment. Based on the relationship, acquire a proposal of manufacturing bidisperse wick structures successfully. In the wick structure’s parameters, the permeability of “the powders mixed” is enhancing 30% by the monodisperse wick structure when the ratio of the two types of the powders is 1：1 , meanwhile, the porosity of the bidisperse wick structure is close to the one of the monodisperse wick structure. Summing up the tested results of the loop heat pipe with the bidisperse and with the monodisperse wick structures, the two types of the bidisperse wick structures have a shorter time of reaching steady state than the time of the monodisperse structure. Indicating the bidisperse structures improves the vapor and liquid distribution in the porous media when vaporization phenomena occur in it. Series of testing results showed that the maximum heat transport capacity of the loop heat pipe with monodisperse structure was up to 200-Watts and the thermal resistance was 0.26℃/W , meanwhile , the one with bidisperse structure of “the powders mixed” by the ratio is 1：1 was up to 300-Watts and the thermal resistance was 0.17℃/W at 80℃ allowable temperature.On the preliminary measuring, the loop heat pipe with bidisperse wick structures is referred to have high potential for the application.第一章 緒 論………………………………………………………………1 1.1研究動機……………………………………………………………1 1.2文獻回顧………………………………………………………………5 1.3研究目的………………………………………………………………7 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………………………………………………………10 2.1.2啟動限制………………………………………………………11 2.1.3液體過冷度限制………………………………………………11 2.1.4補償室體積限制………………………………………………12 2.2理論分析………………………………………………………………13 2.2.1流動壓降分析…………………………………………………13 2.2.1.1液-汽介面之毛細壓差……………………………………13 2.2.1.2蒸發器溝槽內蒸汽流動壓降………………………………13 2.2.1.3汽體段流動壓降…………………………………………14 2.2.1.4流經毛細結構之壓降………………………………………15 2.2.1.5液體段及冷凝段流動壓降…………………………………16 2.2.1.6重力壓降…………………………………………………17 2.2.2熱阻分析……………………………………………………18 2.2.2.1蒸發器熱阻………………………………………………18 2.2.2.2冷凝器熱阻………………………………………………21 2.2.3工質注入量……………………………………………………22 第三章 實驗設備與方法…………………………………………………23 3.1製造系統…………………………………………………………23 3.1.1雙孔徑毛細結構製造系統………………………………………23 3.1.2雙孔徑毛細結構之製造實驗材料………………………………24 3.1.3迴路式熱管製造系統…………………………………………24 3.2測試系統………………………………………………………………24 3.2.1冷態測試系統………………………………………………25 3.2.1.1孔隙度……………………………………………………25 3.2.1.2有效孔徑……………………………………………………27 3.2.1.1滲透度……………………………………………………28 3.2.2熱性能測試系統…………………………………………………29 3.3實驗步驟………………………………………………………………32 3.3.1雙孔徑毛細結構製作步驟………………………………………32 3.3.1.1雙層毛細結構製作流程圖……………………………………32 3.3.1.2混粉毛細結構製作流程圖……………………………………33 3.3.2迴路式熱管熱傳性能測試步驟…………………………………34 3.3.2.1迴路式熱管安裝過程…………………………………34 3.3.2.2 熱性能測試步驟…………………………………………35 3.4誤差分析………………………………………………………36 3.5實驗參數……………………………………………………40 第四章 結果與討論…………………………………………………………41 4.1迴路式熱管之設計……………………………………………41 4.1.1工質選擇………………………………………………42 4.1.2管路材質之選擇………………………………………………… 43 4.1.3迴路式熱管各元件之尺寸……………………………………43 4.2毛細結構製作……………………………………………………46 4.2.1雙孔徑毛細結構之製作…………………………………………46 4.2.1.1粉末大小粒徑的選擇………………………………………47 4.2.1.2燒結溫度和粉末粒徑大小之關係…………………………50 4.2.1.3製作雙層型式毛細結構…………………………………52 4.2.1.4製作混粉型式毛細結構…………………………………54 4.3毛細結構參數量測結果探討……………………………………… 57 4.3.1孔隙度比較……………………………………………………57 4.3.1.1單孔徑毛細結構………………………………………… 57 4.3.1.2雙層雙孔徑毛細結構…………………………………… 57 4.3.1.3混粉型式雙孔徑毛細結構……………………………… 58 4.3.2有效孔徑比較…………………………………………………58 4.4迴路式熱管熱性能測試………………………………………………62 第五章 結論和建議…………………………………………………………66 參考文獻……………………………………………………………………69 附錄…………………………………………………………………………713091551 bytesapplication/pdfen-US雙孔徑毛細結構迴路式熱管燒結the bidisperse wick structuresloop heat pipesinteringthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/61513/1/ntu-94-R90522311-1.pdf