跳到主要內容

臺灣博碩士論文加值系統

(44.210.149.205) 您好!臺灣時間:2024/04/12 22:38
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

我願授權國圖
: 
twitterline
研究生:王銓鈺
研究生(外文):Chuan-yu Wang
論文名稱:甲醇/水混合系統在內含人造孔穴之微流道中的流沸騰特徵
論文名稱(外文):Flow Boiling of Methanol/Water Mixtures in Microchannels with Artificial Cavities
指導教授:孫珍理
指導教授(外文):Chen li Sun
學位類別:碩士
校院名稱:國立臺灣科技大學
系所名稱:機械工程系
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2006
畢業學年度:94
語文別:中文
論文頁數:209
中文關鍵詞:沸騰微流道人造孔穴混合系統雙相流
外文關鍵詞:boilingmicrochannelcavitymixturetwo-phase flow
相關次數:
  • 被引用被引用:0
  • 點閱點閱:163
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
本研究以氧化矽為蝕刻遮罩,以DRIE在矽晶圓上製作內含人造孔穴之微流道,進行甲醇/水混合系統的流沸騰實驗,探討莫耳分率、流道寬度為100 �慆與150 �慆及人造孔穴對流沸騰型態的影響及單相流與二相流之壓力變化。甲醇/水為不具共沸點之混合系統,實驗中所使用之莫耳分率為0 (純水)、0.07、0.3、0.5、0.7、0.9與1 (純甲醇) 共七種,流體之體積流率設定為0.02 ml/min。實驗結果顯示由常溫加熱至完全汽化,主要出現三種流沸騰型態,所對應的過熱溫度由低至高依序為塊狀流 (slug flow)、環狀流 (annular flow) 與霧狀流 (mist flow)。
對於甲醇/水混合系統而言,增加甲醇莫耳分率會使表面張力下降,有助於氣泡在微流道中之流動,且氣液介面亦較平滑,可避免頸縮現象發生。對於普通流道而言,流道寬度對流沸騰型態之變化並不明顯;對於內含人造孔穴之流道而言,流道寬度縮小使沸騰初始之氣泡體積變小。而對於寬度為100 �慆之流道,放置人造孔穴亦可使沸騰初始之氣泡體積變小;對於寬度為150 �慆之流道,放置人造孔穴可改善slug flow型態之氣泡流動性,避免發生氣泡堆積現象。
流道型態固定時,在單相流中,溫度上升使工作流體性質改變,單相壓力隨系統溫度上升而降低。當甲醇莫耳分率x �T 0.5時,混合系統中之預溶氣體在過冷狀態即釋出,使壓力變大,提高甲醇莫耳分率會使沸騰初始及mist flow型態之壓力降低。莫耳分率固定時,放置人造孔穴可略為降低沸騰初始及完全進入mist flow型態時所對應之過熱溫度。
對於沸騰後的二相流壓力變化,利用實驗結果估算孔隙率 (void fraction),以Lockhart-Martinelli模型與均質模型 (homogeneous model) 計算二相流之摩擦壓降,發現對於甲醇/水混合系統,莫耳分率為影響二相流中摩擦壓降的重要因素。當莫耳分率愈高,摩擦壓降與量測總壓降之差距愈小。
In this study, flow boiling of methanol/water mixtures in microchannel is investigated under isothermal heating condition. The mole fractions of methanol in water tested are 0 (pure water), 0.07, 0.3, 0.5, 0.7, 0.9 and 1 (pure methanol). The widths of the microchannels are 100 �慆 and 150 �慆, while the depth and length are 150 �慆 and 1.6 mm, respectively. The bottom surfaces of the microchannels are treated by DRIE to produce artificial cavities with a diameter of 12 �慆. A syringe pump is used to deliver the mixtures and the flow rate is set to 0.02 ml/min.
There are three typical boiling regimes identified: the slug flow, the annular flow and the mist flow. For methanol/water mixtures, increasing the mole fraction decreases the surface tension and results in smaller bubbles in slug flow. It also makes the liquid-vapor interface smoother to avoid the formation of necking instability in annular flow. Moreover, by adding artificial cavities to the microchannels, bubble sizes are reduced and the required superheats of boiling incipience and transition to mist flow are both decreased.
In general, the single-phase pressure drop in microchannel decreases with increasing the system temperature and increases eruptly after the initiation of phase change. For x �T 0.5, however, dissolved gases tend to release at subcooling condition, causing the pressure drop to increase before boiling incipience. Void fraction is estimated from experimental results to calculate the frictional pressure drop of two-phase flow by employing the Lockhart-Martinelli parameter and homogeneous model. It is found that the higher mole fraction the more significant contribution of the frictional pressure drop to the total pressure drop. For x �d 0.5, the frictional pressure drop proves to dominate the total pressure drop for two-phase flow in microchannels.
摘要 i
Abstract ii
目錄 iii
符號索引 vi
表目錄 ix
圖目錄 x
第一章 緒論 1
1.1 研究動機 1
1.2 文獻回顧 2
1.3 研究目的 5
第二章 二元混合系統的物理性質 6
2.1 二元混合系統的相圖 6
2.2 二元混合系統的物理性質變化 6
2.3 Marangoni effect對於沸騰的影響 8
第三章 微流道設計與製程步驟 10
3.1 微流道設計 10
3.1.1 流道貫穿孔 10
3.1.2 流道主體 10
3.1.2 流道底部的人造孔穴 11
3.2 光罩設計 12
3.3 微流道製程 13
3.3.1 清潔矽晶圓表面有機物及原生氧化矽 13
3.3.2 沈積二氧化矽薄膜 13
3.3.3 第一次微影 14
3.3.4 第一次深反應離子蝕刻 (Deep Reactive Ion Etching, DRIE) 16
3.3.5 第二次微影 16
3.3.6 第一次反應式離子蝕刻 (Reactive Ion Etching, RIE) 17
3.3.7 第三次微影 17
3.3.8 第二次深反應離子蝕刻 17
3.3.9 第二次反應式離子蝕刻 18
3.3.10 第三次深反應離子蝕刻 18
3.3.11 電子顯微鏡觀察 18
3.4 封裝與其他後續製程 19
3.4.1 陽極接合 19
3.4.2 晶圓切割 19
3.4.3 元件夾持與管路連接 19
第四章 實驗量測與不確定性分析 20
4.1 實驗設備 20
4.1.1 注射式泵與玻璃針筒 20
4.1.2 數字型精密加熱板 20
4.1.3 熱電偶 21
4.1.4 水銀溫度計 21
4.1.5差壓感測器 21
4.1.6放大調節器 21
4.1.7資料擷取卡 22
4.1.8 探針測試平台 22
4.1.9 工作流體 22
4.2 實驗量測 22
4.3 不確定性分析 23
4.3.1 壓力 24
4.3.2 溫度 25
4.3.3 莫耳分率 25
4.3.4 體積流率 26
4.3.5 無因次參數 27
第五章 實驗結果與分析 29
5.1 流沸騰型態觀察 29
5.1.1 流道寬度為100 �慆 29
5.1.2 流道寬度為150 �慆 36
5.2 壓力變化 43
5.2.2 流道寬度為100 �慆 43
5.1.2 流道寬度為150 �慆 50
5.3 莫耳分率對流沸騰的影響 57
5.3.1 流沸騰型態 57
5.3.2 壓力變化 59
5.4 流道寬度對流沸騰的影響 62
5.4.1流沸騰型態 62
5.4.2壓力變化 63
5.5 人造孔穴對流沸騰的影響 65
5.5.1流沸騰型態 65
5.5.2壓力變化 67
第六章 討論 69
6.1 流沸騰regime map 69
6.1.1 流道寬度為100 �慆 69
6.1.3 流道寬度為150 �慆 71
6.2 二相流壓力 72
6.2.1 孔隙率計算 72
6.2.2 二相摩擦multiplier 73
6.2.3 由Lockhart-Martinelli關係式計算摩擦壓降 75
6.2.4 由均質模型計算摩擦壓降 76
第七章 結論與建議 78
7.1 結論 78
7.2 建議 79
參考文獻 80
附錄A 82
附錄B 84
[1]H. Y. Wu and P. Cheng, "Visualization and measurements of periodic boiling in silicon microchannels," International Journal of Heat and Mass Transfer, vol. 46, pp. 2603-2614, 2003.
[2]P. C. Lee, F. G. Tseng, and C. Pan, "Bubble dynamics in microchannels. Part I: Single microchannel," International Journal of Heat and Mass Transfer, vol. 47, pp. 5575-5589, 2004.
[3]J. Li and P. Cheng, "Bubble cavitation in a microchannel," International Journal of Heat and Mass Transfer, vol. 47, pp. 2689-2698, 2004.
[4]V. P. Carey, Liquid-Vapor Phase-Change Phenomena: An Introduction to the Thermophysics of Vaporization and Condensation Processes in Heat Transer Equipment. New York: Hemisphere, 1992.
[5]L. Zhang, E. N. Wang, K. E. Goodson, and T. W. Kenny, "Phase change phenomena in silicon microchannels," International Journal of Heat and Mass Transfer, vol. 48, pp. 1572-1582, 2005.
[6]S. Chatpun, M. Watanabe, and M. Shoji, "Experimental study on characteristics of nucleate pool boiling by the effects of cavity arrangement," Experimental Thermal and Fluid Science, vol. 29, pp. 33-40, 2004.
[7]X. F. Peng, G. P. Peterson, and B. X. Wang, "Flow boiling of binary mixtures in microchanneled plates," International Journal of Heat and Mass Transfer, vol. 39, pp. 1257-1264, 1996.
[8]X. F. Peng and G. P. Peterson, "Forced convection heat transfer of single-phase binary mixtures through microchannels," Experimental Thermal and Fluid Science, vol. 12, pp. 98-104, 1996.
[9]L. H. Chai, X. F. Peng, and D. J. Lee, "Interfacial effects on nucleate boiling heat transfer of binary mixtures," International Journal of Thermal Sciences, vol. 40, pp. 125-132, 2001.
[10]W. R. McGillis and V. P. Carey, "On the role of Marangoni effects on the critical heat flux for pool boiling of binary mixtures," International Journal of Heat and Mass Transfer, vol. 118, pp. 103, 1996.
[11]K. Mishima and T. Hibiki, "Some Characteristics of Air-water Two-Phase Flow in Small Diameter Vertical Tubes," International Journal of Multiphase Flow, vol. 22, pp. 703-712, 1996.
[12]A. Kawahara, P. M. Y. Chung, and M. Kawaji, "Investigation of two-phase flow pattern, void fraction and pressure drop in a microchannel," International Journal of Multiphase Flow, vol. 28, pp. 1411-1435, 2002.
[13]A. E. Dukler, M. Wicks III, and R. G. Cleveland, "Pressure drop and hold-up in two-phase flow," AIChE Journal, vol. 10, pp. 38-51, 1964.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top