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姓名 陳勁廷(Jin-Ting Chen) 查詢紙本館藏 畢業系所 機械工程學系 論文名稱 微多孔塗層兩相蒸發冷卻器研究 相關論文 檔案 [Endnote RIS 格式]
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至系統瀏覽論文 ( 永不開放)
摘要(中) 由於電子設備的快速發展，高熱通量的散熱變得更加重要。在過去的幾
十年裡，已經使用諸如空氣冷卻和液體冷卻系統等成熟技術，獲得了出色的
熱管理解決方案。但是，由於熱傳係數低，它們不再是可行的解決辦法。兩
相冷卻系統為更高的熱傳提供了一種可能的解決方案。若欲傳遞相同熱傳量，
由於液體之潛熱遠高於顯熱，兩相冷卻所需要的流量和泵動力比單相冷卻低
得多，能夠降低所需要的泵動力。一般對於池沸騰熱傳之增強，多於蒸發表
面製作結構表面或多孔表面，以增加其活化孔穴數量。多孔表面則是由不同
或單一尺寸之金屬顆粒，以燒結或電鍍等方式製作而成，粒子堆疊會產生孔
穴以及互相連接的通道。傳統的多孔材料塗層較厚，導致加熱表面與蒸發表
面之間的熱阻較大，因此多孔表面的傳熱性能下降。微孔表面可以改善這個
問題，因為微孔表面全部位於過熱區域，所以更容易產生氣泡，而多孔層較
薄，熱阻也較小。在本研究中，我們設計了不同直線流道大小的蒸發熱交換
器，並使用平均顆粒尺寸為 20 μm 的鋁粉塗佈於蒸發冷卻器上，來比較有塗 層和非塗層熱交換器的熱傳性能。
實驗結果顯示微多孔表面，鰭片間距 2mm，在高熱通量時熱傳增強效果
較好，與平滑表面相比，提升 17%~62%，且微多孔表面的粒子堆積會形成互
相連結的通道，可幫助液體補充至加熱表面，與平滑表面相比，微多孔表面
的燒乾情形會延後發生。微多孔表面，鰭片間距 1mm 因為鰭片間距較小，
汽泡生成後，容易與周圍的汽泡結合。所以其熱傳增強效果比鰭片間距 2mm
時低。摘要(英) Due to the rapid development of electronic equipment, dissipating heat from
high heat flux sources becomes more important. For the past few decades, excellent
thermal management solutions have been attained using well-established
technologies such as air cooling and liquid cooling system. However, they are no
longer viable solutions due to low heat transfer coefficient. Therefore, there is an
increasing need for compact and high heat-flux thermal management system. Two
phase cooling system offers a potential solution for higher heat transfer.
Considering the same heat transfer coefficient, two-phase flow required much
lower flow rate and pumping power compare to single-phase flow, as result of
higher heat transfer coefficient of two phase flow.
Surface structure or porous surface due to increasing the cavity and nucleation
site, can enhance the pool boiling heat transfer coefficient. Porous surface is made
of different or single-size metal particles, and the stack of particles will produce
cavities and interconnected channels. Cavities increase the nucleation sites which
generate more bubbles, while the interconnected flow paths provide fluid flow and
bubble escape path. The traditional porous material coating is thick, which cause a
large thermal resistance between the heating surface and the evaporation surface,
therefore heat transfer performance of the porous surface decreases. Micro-porous
surface can improve this problem, because micro-porous surface is all in the
superheat region, it is easier to produce bubbles while the porous layer is thin,
thermal resistance is also small.
In this study, we designed different size of straight fin type heat exchanger
and use Aluminum powder with average particle size of 20 μm, micro porous used to coating those heat exchanger to compare the heat transfer performance of coating
and non-coating heat exchanger.
The experimental results show that the microporous surface has a fin spacing
of 2 mm. The heat transfer enhancement effect is better at high heat flux, which is
17%~62% higher than that of the smooth surface, and the particle accumulation on
the microporous surface forms a channel that is mutually entangled. It helps to
replenish the liquid to the heated surface, and the dry out of the microporous surface
is delayed compared to the smooth surface. Microporous surface with fin spacing
1mm, because the fin spacing is small, after the bubble is generated, it is easy to
combine with the surrounding bubbles. Therefore, the heat transfer enhancement effect is lower than when the fin pitch is 2 mm.關鍵字(中) ★ 微多孔表面
★ 兩相冷卻
★ 直線流道關鍵字(英) ★ Micro porous coating
★ Two Phase cooling
★ Straight fin channel論文目次 摘要 .......................................................................................................................... i
Abstract .................................................................................................................... ii
目錄 ........................................................................................................................ iv
圖目錄 ................................................................................................................... vii
表目錄 ..................................................................................................................... x
符號說明 ................................................................................................................ xi
第一章、前言 ......................................................................................................... 1
1.1 研究背景與動機 ....................................................................................... 1
1.2 研究目的 .................................................................................................. 3
第二章 文獻回顧 ................................................................................................... 7
2.1 多孔表面熱傳增強 .................................................................................. 7
2.1.1 微多孔表面熱傳增強 ................................................................... 8
2.1.2 多孔層厚度對熱傳的影響 ......................................................... 10
2.1.3 製作方式對熱傳的影響 ............................................................. 11
2.2 兩相蒸發微流道冷卻器之熱傳性能 .................................................... 12
2.3 微流道熱交換器內流動現象 ................................................................ 13
2.4 熱傳增強之兩相蒸發冷卻器熱傳性能 ................................................ 14
2.5 總結 ........................................................................................................ 16
表 2.1、冷卻技術文獻整理 ................................................................................. 17
第三章 實驗方法 ................................................................................................. 44
3.1 兩相蒸發冷卻器之流道設計 ................................................................ 44
3.1.1 直線流道設計 ............................................................................. 44
3.1.2 微多孔表面直線流道製作 ......................................................... 47
v
3.1.2.1 製作步驟 .......................................................................... 48
3.1.2.2 噴塗參數 ........................................................................... 49
3.1.3 熱交換器組合 ............................................................................. 49
3.2 實驗系統 ................................................................................................ 49
3.2.1 加熱系統 ..................................................................................... 50
3.2.2 實驗量測儀器與設備 ................................................................. 50
3.2.2.1 溫度量測 .......................................................................... 50
3.2.2.2 流量量測 .......................................................................... 51
3.2.2.3 差壓量測 .......................................................................... 51
3.2.3 資料擷取系統 ............................................................................. 51
3.3 實驗步驟 ................................................................................................ 51
3.4 實驗數據換算 ........................................................................................ 52
3.4.1 加熱瓦數 ..................................................................................... 52
3.4.2 質量流率 ..................................................................................... 53
3.4.3 乾度 ............................................................................................. 53
3.4.4 熱傳係數 ..................................................................................... 53
3.4.5 熱阻值 ......................................................................................... 54
第四章、實驗結果與討論 ................................................................................... 71
4.1 熱傳性能之實驗結果 ............................................................................ 71
4.1.1 平滑表面直線流道蒸發冷卻器之熱傳性能 ............................. 71
4.1.2 微多孔塗層蒸發冷卻器之熱傳性能 ....................................... 72
4.2 蒸發冷卻器之壓降性能 ........................................................................ 74
4.3 可視化結果與熱傳性能之關係 ............................................................ 75
4.3.1 平滑表面直線型流道可視化結果與熱傳性能之關係............. 75
vi
4.3.2 微多孔表面直線流道可視化結果與熱傳性能之關係............. 76
第五章、結論 ....................................................................................................... 97
參考文獻 ............................................................................................................... 98
附錄(一)、實驗誤差分析 .................................................................................. 102
附錄(二)、熱邊界層計算 .................................................................................. 105參考文獻 [1] https://www.electronics-cooling.com/ [2] 李至誠，2017，不同流道型式之蒸發熱交換器的熱傳性能研究，國立
中央大學機械工程研究所碩士論文，中壢，台灣。
[3] http://www.1-act.com/advanced-technologies/pumped-two-phase-cooling/ [4] “Pumped Two-Phase Cooling Solutions for Challenging Thermal Management Application,” Advanced Cooling Technologies, Inc. 2015. [5] Yang, C.-Y., and Fan, C.-F., 2006, “Pool boiling of refrigerants R-134a and R-404A on porous and structured surface tubes – Part II, heat transfer performance,” J. Enhanced Heat Transfer, Vol. 13, pp. 65-84 [6] 范智峰，2004，冷媒 R-134a 與 R-404A 在熱傳增強管上之池沸騰觀
察與熱傳性能分析，國立中央大學機械工程研究所博士論文，中壢，
台灣。
[7] Collier, J. G., and Thome, J. R., 1994, Convective Boiling and Condensation, Third Edition. Oxford University Press New York. Chapter 4, pp. 148-151. [8] Yang J., 2005, ‘‘Development of heat transfer enhancement techniques for external cooling of an advanced reactor vessel,’’ Ph. D thesis, Department of Mechanical Engineering, Pennsylvania State University, USA. [9] Chang, J. Y., and You, S. M., 1997a, “Boiling heat transfer phenomena from micro-porous and porous surfaces in saturated FC-72,” Int. J. Heat Mass Transfer, Vol. 40, pp. 4437-4447. [10] Webb, R. L., “Principles of Enhanced Heat Transfer” 2th, Taylor & Francis, New York, 2005. [11] O’Connor, J. P., and You, S. M., 1995 “A painting technique to enhance pool boiling heat transfer in FC-72,” ASME J. Heat Transfer, Vol. 117, pp. 387-393. [12] Chang, J. Y., and You, S. M., 1996, “Heater orientation effects on pool boiling of micro-porous-enhanced surfaces in saturated FC-72,” ASME J. Heat Transfer, Vol. 118, pp. 937–943. [13] Chang, J. Y., and You, S.M., 1997b, “Enhanced boiling heat transfer from micro-porous surfaces: effects of a coating composition and method,” Int. J. Heat Mass Transfer. Vol. 40, pp. 4449–4460. [14] Cieslinski, J. T., 2002, “Nucleate pool boiling in porous metallic coatings,” Exp. Therm. Fluid Sci., Vol. 25, pp. 557-564. [15] Li, C., and Peterson, G. P., 2007, “Parametric study of pool boiling on horizontal highly conductive microporous coated surfaces” ASME J. Heat Transfer, Vol. 129, pp. 1465-1475. [16] Alam, M. S., Prasad, L., Gupta, S. C., and Agarwal, V. K., 2008, “Enhanced boiling of saturated water on copper coated heating tubes,” Chem. Eng. Process., Vol. 47, pp. 159-167. [17] El-Genk, M. S., and Ali, A. F., 2010, “Enhanced nucleate boiling on copper micro-porous surfaces,” Int. J. Multiphase Flow, Vol. 36, pp. 780792. [18] Yang, C.-Y., and Liu, C.-F., 2013, “Effect of Coating Layer Thickness for Boiling Heat Transfer on Micro Porous Coated Surface in Confined and Unconfined Spaces,” Exp. Therm. Fluid Sci., Vol. 47 pp. 40-47. [19] Yang, J., and Cheung, F.-B., 2005, “A hydrodynamic CHF model for downward facing boiling on a coated vessel,” Int. J. Heat Fluid Flow, Vol. 26, pp. 474-484. [20] Tuckerman, D. B., and Pease , R.F.W., 1981, “High-performance heat sinking for VLSI,” IEEE Electron Devices Society, Vol. 2, pp. 126-129 [21] Agostini, B., Fabbri, M., Park, J.E., Wojtan, L., Thome, J.R., and Michel, B., 2007, ”State of the Art of High Heat Flux Cooling Technologies,” Heat Transfer Engineering, Vol. 28, No. 4,pp. 258-281. [22] Cornwell, K., and Kew, P. A., 1992, “Boiling in small parallel channels,” Proceedings of CEC Conference on Energy Efficiency in Process Technology, Athens, Elsevier Applied Sciences, pp. 624–638 [23] Balasubramanian, P., and Kandlikar, S. G., 2005, ”Experimental study of flow patterns, pressure drop and flow instabilities in parallel rectangular minichannels, ” Heat Transfer Engineering, Vol. 26, pp. 20-27. [24] Lee, J., and Mudawar, I., 2008, “Fluid flow and heat transfer characteristics of low temperature two-phase micro-channel heat sinks – Part 1: Experimental methods and flow visualization results,” International Journal of Heat and Mass Transfer, Vol. 51, pp. 4315-4326. [25] Sun, Y., Zhang, L., Xu, H., Zhong, X., 2011, ‘‘Subcooled flow boiling heat transfer from microporous surfaces in a small channel,” Int. J. Thermal Sciences, Vol. 50, pp. 881-889. [26] Bai, P., Tang, T., and Tang, B., 2013, “Enhanced flow boiling in parallel microchannels with metallic porous coating, ” Applied Thermal Engineering, Vol. 58, pp. 291-297. [27] Deng, D., Chen, R., Tang, Y., Lu, L., Zeng, T., and Wan, W., 2005, “A comparative study of flow boiling performance in reentrant copper microchannels and reentrant porous microchannels with multi-scale rough surface,” International Journal of Multiphase Flow, Vol. 72, pp. 275-287. [28] Sujith Kumar C. S., Suresh S., Yang, Q., and Aneesh, C.R. 2005, “An experimental investigation on flow boiling heat transfer enhancement using spary pyrolysed alumina porous coating,” Applied Thermal Engineering, Vol. 71, pp. 508-518 [29] Fritz, W., 1935, “Berechnung des Maximal Volumens von Dampfblasen,” Phys. Z., Vol. 36., Quoted in [16] [30] Shah, M. M., 1976, “A New Correlation for Heat Transfer during Boiling Flow Through Pipes,” ASHRAE Transaction, Vol. 82, No. 2, pp. 66-86. [31] Kandlikar, S. G., and Balasubramanian, P., 2004, “An extension of the flow boiling correlation to transition, laminar, and deep laminar flows in minichannels and microchannels,” Heat Transfer Engineering, Vol. 25, pp. 86-93.指導教授 楊建裕(Chien-Yuh Yang) 審核日期 2018-8-14 推文 plurk
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