補償室與蒸發區微結構對平板型迴路式熱管特性影響之研究

Study on the Performance of flat Loop Heat Pipe in the Wick of Compensation Chamber and Evaporation Zone

褚伊銘(Yi-Ming Chu)

指導教授 ： 蘇程裕

國立臺北科技大學/機電學院/機電整合研究所/碩士(2010年)

摘要

迴路式熱管為一種以熱管與均熱板為理論基礎的兩相變化熱導的被動式冷卻系統，其相對於傳統熱管更具有高熱傳量、傳輸距離長與低熱阻的表現，在電子科技冷卻上與其它散熱應用上皆持續成為重要的研發重點與發展空間。平版型迴路式熱管的設計可直接與發熱元件貼覆，但於啟動過程中，系統中的工作流體到達重新分布，會發生如蒸發、冷凝、沸騰等相變化現象，使得系統各元件熱流狀態極不穩定。操作過程中也因為沸騰汽泡與熱洩漏等原因，影響了系統的穩定度。故迴路式熱管的啟動與操作穩定一直是各界研究之目標。
本研究中使用兩種不同粒徑、不同材料之粉末，以刮刀成型法方式製成粗坯並燒結，製成平板型迴路式熱板之複合毛細微結構。在主微結構部份以400網目銅粉末燒結使其具有較大的毛細力與較好之熱傳量，次結構以150網目鎳粉製作，其具有良好的滲透率與較低熱傳導係數值阻擋補償室受熱影響。利用刮刀成型後之粗坯可進行單次直接燒結於平板型迴路式熱管下蓋，降低製程中之誤差。實驗中分別注水6.2g、8.6g及10.6g並量測其性能。分析測試結果呈現，此研究設計之迴路式熱管在操作循環中並無明顯的會影響元件之熱振盪，並且不受傾斜角度影響，於注水量為6.2g時有最佳的效能表現，最低熱阻值為0.21℃/W。另外對補償室額外散熱時，有助於增加操作穩定性與降低整體熱阻。

關鍵字

平板型迴路式熱管 ； 毛細結構 ； 燒結 ； 補償室

並列摘要

Loop Heat Pipe is a kind of heat pipe with both vapor chamber based on the theory of two-phase change thermal conductivity of the passive cooling system. Compared to the conventional heat pipe, loop heat pipe has a high heat transfer capacity, transmission distance of a long and low thermal resistance performance in cooling, space technology or military technology and other thermal applications. The flat loop heat heating element can be placed on the heat source directly without using saddle. During the startup process, the working fluid in the system will be distributed and phase transition including evaporation, condensation and boiling will occur, leading to the thermal status for each component unstable. In addition, boiling bubbles and thermal leakage also influence the system stability. Therefore, the start up and stable operation for the loop heat pipe is the aim to investigate in various research fields.
In this study, two different sizes, different material powder were used. The wick structure of flat loop heat pipe can be fabricated to green tape with sinter process by using doctor blade casting. The first part, the sintered 400 mesh copper powders have higher capillarity and the better the heat transfer rate. In secondary part, 150 mesh nickel powders, have good permeability and lower capillarity to resist heat leaking to compensation chamber. The green tape made by doctor blade casting can be sintered to chamber of flat loop heat pipe for single time. It can decrease the error during the manufacturing. In the experiment, various water contents of 6.2g, 8.6g and 10.6g were injected to measure the performance. According to the characterization, the flat loop heat pipe has no obvious thermal oscillation and performs freely during the operation. The results show that the 6.2g water content injection has the lowest heat resistance of 0.21 ℃ / W. In addition, the compensation chamber for additional cooling can increase the operation stability and decrease the system thermal resistance.

並列關鍵字

Flat Loop Heat Pipe ； Wick Structure ； Sinter ； Compensation Chamber

參考文獻

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