臺灣博碩士論文加值系統

　　傳統熱管以去離子水作為熱管之工作流體，本研究是使用奈米銀流體來取代之。奈米銀流體是以水相合成法製備，並將此流體充於溝槽型熱管，並藉由熱傳實驗測試方式，驗證改變工作流體後，熱管性能是否能有效提升。
　　本研究是用長度150mm，直徑6mm之熱管，而實驗中以去離子水為工作流體時，平均最大熱傳量為35W；而以奈米銀流體為工作流體，平均最大熱傳量為40∼42W，可有效提升17∼18％。於熱反應測試中，使用去離子水、15nm奈米銀流體、35nm奈米銀流體，其熱反應時間分別為18∼20秒、14∼16秒、16∼17秒可達穩態，故奈米銀流體比去離子水之熱反應快速。實驗結果亦顯示使用去離子水為工作流體，兩端（蒸發端與冷凝端）溫差為2.5℃∼3.5℃，而奈米銀流體，粒徑為15nm與35nm，溫差平均值為2.731℃、3.85℃。調整不同濃度時，發現低濃度（10~50ppm）平均值則為2.34℃。而於熱阻之測試，值經由溫差與功率計算後，去離子水為0.16℃/W，奈米銀15nm與35nm分別為0.137℃/W和0.131℃/W。
　　由上述皆可知使用奈米銀流體確實可提升熱管之最大熱傳量，且在低濃度尤甚，且也可增加傳熱速率，總體而言，可提升熱管效能。
若能大量批次化量產，將可對熱管產業帶來一衝擊與新的商業模式。

DI water is generally used as the working fluid for heat pipe. In this study, silver nanofluid takes the place of DI water. Silver nanofluid is synthesized by using the aqueous method and the heat pipe is grooved type. With heat transfer experiments, this paper is to verify whether silver nanofluid could effectively enhance the performance of heat pipe.
In this work, the heat pipe is 150 mm in length and 6 mm in diameter. In the test of maximum heat transfer rate, the average value is 35 W for DI water and 40~42 W for silver nanofluid, which has 17~18% performance increase. In the thermal response test, the response time to reach steady state for DI water is 18~20 seconds and they are 14~16 and 16~17 seconds for 15 nm and 35 nm silver nanofluid, respectively. Accordingly, silver nanofluid has the smaller response time. At the steady state of the test, the temperature difference of evaporation and condensation ends is 2.5�aC~3.5�aC for DI water and the average differences are 2.731�aC and 3.85�aC for 15 nm and 35 nm silver nanofluid. Besides, the average temperature difference could reach 2.34�aC for low concentration (10~50ppm) of silver nanofluid. In thermal resistance test, the value is 0.16�aC /W for DI water and they are 0.137�aC /W and 0.131�aC /W for 15 nm and 35 nm silver nanofluid.
From the results shown above, the silver nanofluid could promote the thermal performance of heat pipe, especially at the low concentration. If mass production could be applied, the usage of silver nanofluid will bring impact and new business models to heat pipe.

摘要.............................................................................................................I
英文摘要.....................................................................................................I
誌謝...........................................................................................................III
目錄.........................................................................................................IV
圖目錄....................................................................................................VIII
表目錄........................................................................................................X
第一章 緒論...............................................................................................1
1.1 前言...............................................................................................1
1.2 研究動機.......................................................................................2
1.3 文獻回顧.......................................................................................3
第二章 熱管理論基礎..............................................................................8
2.1. 熱管構造及工作原理..................................................................8
2.2 熱管使用上的限制.......................................................................9
2.2.1 毛細溝槽限制.....................................................................9
2.2.2 飛散限制.............................................................................9
2.2.3 沸騰限制...........................................................................10
2.2.4 黏滯限制...........................................................................10
2.2.5 音速限制...........................................................................11
2.3 熱管使用之最大熱通量............................................................11
2.4 奈米流體之熱傳導係數理論分析............................................12
第三章 實驗方法與設備........................................................................16
3.1 實驗方法.....................................................................................16
3.2 實驗材料製作.............................................................................16
3.2.1 熱管製作...........................................................................16
3.2.2 奈米流體制備...................................................................17
3.2.3 工作流體濃度調配...........................................................19
3.3 流體性質.....................................................................................20
3.4 量測方法.....................................................................................21
3.4.1 暫態熱反應之測試...........................................................21
3.4.2 最大熱傳量之測試...........................................................22
3.5 實驗參數.....................................................................................22
3.6 實驗儀器.....................................................................................23
第四章 實驗結果與討論........................................................................37
4.1 最大熱傳量（Q`max）.............................................................37
4.1.1 比較相同粒徑，不同濃度下之最大熱傳量..................38
4.1.2 比較相同濃度，不同粒徑下之最大熱傳量..................38
4.2 比較熱反應速率.........................................................................39
4.3 流體物理性質.............................................................................40
4.3.1 密度...................................................................................40
4.3.2 熱傳導係數量測...............................................................41
4.4 從最大熱傳量比較熱阻值........................................................42
第五章 結論.............................................................................................51
參考文獻...................................................................................................53

[1] R.S. Gaugler, “Heat Transfer Devices,” US Patent 2350348, Appl.21 December1942, Published 6 June 1966.

[2] Stephen U.S. Choi and J. A. Eastman, Enhancing thermal conductivity of fluids with nanoparticles, Tech.Rep.Fed,Vol.231,MD66, ASME,1995

[3] C.Y. Tsai, H.T. Chien, B. Chan, P.H. Chen, P.P. Ding, T.Y. Luh, Effect of structural character of gold nano-particles in nanofluid on heat pipe thermal performance, Material Letters 58(2004)

[4] Shung-Wen Kang, Wei-Chiang Wei, Sheng-Hong Tsai, Chia-Ching Huang, Experimental investigation of nanofluids on sintered heat pipe thermal performance, 2008

[5] Eastman J.A,S.U.S.Choi,S,Li,W.Yu,L.J.Thompson, Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles Appl. Phys. Lett. 78, 718 (2001); DOI:10.1063/1.1341218

[6] H.Masuda,A.Ebata,K.Teramea,N.Hishinuma,Alteration of thermal conductivity and viscosity of liquid by dispersing ultra fine particles, Netsu Bussei 4(1993).

[7] G.P.Peterson, An introduction to heat pipes: modeling, testing, and Application, John Wiley &Sons, Inc,1994.

[8] Hsin Tang chien, Chien In Tasi, Ping Hei Chen, Po Yeh Chen, Improvement on thermal performance of a disk shaped miniature heat pipe with nanofluid, ICEPT2003

[9] W.C. Wei, S.H. Tsai, S.Y. Yang, S.W. Kang, Effect of nano-fluid concentration on heat pipe thermal performance, IASME Transaction 2(2005)
[10] S.W. Kang, W.C. Wei, S.H. Tsai, S.Y. Yang, Experimental investigation of silver nano-fluid on heat pipe thermal performance, Applied Thermal Engineering 26(2006)

[11]趙宴佑，“嵌入式熱管散熱效益之研究，�訄磪艀言\大學工程科學系，2000。

[12]日本熱管技術協會編，�邾鷅犑瑋N理論實務（HEAT PIPE TECHNOLOGY，�迡_興出版社，2000。

[13]簡欣堂，�虳`米微粒流體應用於光電散熱元件之實驗分析，�訄磪艄x灣大學機械工程學系，2004

[14] 賴衍村，“熱管散熱效益之研究，�訄磪艀言\大學工程科學系，2001。

[15]余騰煥，�衁鷵敯鶶B理學，�苳誚X出版社，1977

[16]陸志鴻，�衁鷵敯鷊＃龤A�苳什篨鰼韙u程學會出版，1966

[17]馬承九，�郋鰼韙u作法，�苳T民書局印行，1973

[18]許鴻川，�苭H實驗計畫法探討燒結型熱管性能，�訄磪艀言\大學工程科學系，2008

[19]李炳仁，�邾鷅瑂s作與熱沉鑄造之實驗研究與數值分析，�訄磪艀言\大學工程科學系，2004

[20] Chang, G., et al., Silver-nanoparticle-attached indium tin oxide 　　surfaces fabricated by a seed-mediated growth approach. J Phys
Chem B, 2005. 109(3): p. 1204-9