臺灣博碩士論文加值系統

本研究探討R-141b冷媒分別在9.5 mm內徑的水平絕熱不鏽鋼管與10.2 mm內徑的水平加熱玻璃管內的雙相流動壓降特性。本實驗系統為一強制對流循環迴路，冷媒質量通率的操作範圍是在1163 與 1768 kg/m2s 之間，以高溫的熱水作為熱源來加熱冷媒使之達到沸騰狀態，由於熱水的流量相當大，其溫度於加熱段出入口處變化不大，使得冷媒的沸騰近似於等水溫的條件。
在絕熱測試段的壓降實驗結果指出，R-141b於水平管內的雙相摩擦加乘因子略小於弗瑞岱爾(Friedel)預估式所預測之值，大約有24 % 的平均偏差，故本研究發展一修正弗瑞岱爾預估式的經驗公式，其能有效預測R-141b冷媒的實驗數據在 ± 19 % 的誤差範圍之內。本研究同時也觀察絕熱段前之玻璃管內的雙相流譜並且以之說明蒸氣乾度與質量通率對壓降的效應。此外，本文也發展了加熱玻璃管沸騰時的雙相摩擦壓降之經驗公式，其能以雷諾數(Reynolds number)與溫差或是雷諾數與加熱功率的形式來預測雙相摩擦壓降。

The present study investigates the characteristics of two-phase flow pressure drop for R-141b in a horizontal adiabatic stainless-steel tube and a diabatic glass tube with inner diameters of 9.5 mm and 10.2 mm, respectively. The operating range of refrigerant mass flux is between 1163 and 1768 kg/m2s. The two-phase flow patterns are visualized in the heating glass tube, which is in the very upstream of the stainless-steel tube, and the effect of vapor quality and mass flux on pressure drop is demonstrated with the flow pattern. The Friedel correlation is also modified to predict the two-phase frictional multiplier of R-141b in the horizontal tube in the present study. In addition, correlations of two-phase frictional pressure drop in the diabatic glass tube are also developed.

ABSTRACTⅠ
CONTENTSⅡ
LIST OF TABLES Ⅳ
LIST OF FIGURES Ⅴ
NOMENCLATURE Ⅷ
CHAPTER 1 INTRODUCTION 1
1.1 Study Motivation 1
1.2 Study Background 1
1.3 Study Objectives and Method 2
1.4 Outline of the Thesis 2
CHAPTER 2 LITERATURE REVIEW 4
2.1 Well-Known Correlations 4
2.2 Two-Phase Pressure Drop in Enhanced Tubes 7
2.3 Effect of Refrigerant-Oil on Pressure Drop 9
2.4 Two-Phase Flow Pattern 11
CHAPTER 3 EXPERIMENTAL APPARATUS AND PROCEDURE 13
3.1 Experimental Apparatus 13
3.2 Experimental Procedure 17
3.3 Uncertainty Analysis 17
CHAPTER 4 THEORETICAL ANALYSIS 26
4.1 Liquid-Phase Friction Factor 26
4.2 Two-Phase Frictional Multiplier 27
4.3 Two-Phase Pressure Drop and Inlet Quality for the Diabatic
Test Section 29
CHAPTER 5 EXPERIMENTAL RESULTS AND DISCUSSION 32
5.1 Liquid-Phase Friction Pressure Drop 32
5.2 Two-Phase Frictional Pressure Drop in an Adiabatic SUS304
Stainless-Steel Tube 36
5.3 Two-Phase Pressure Drop in a Diabatic Pyrex Glass Tube 51
CHAPTER 6 CONCLUDING REMARKS 61
REFERENCES 63

1.B. Pierre, “Flow Resistance with Boiling Refrigerants─Part Ⅰ,”ASHRAE Journal, pp.58-65, September 1964. (Paper reviewed in Ref.[13])
2.C. C. Wang, C. S. Chiang, and D. C. Lu, “Visual Observation of Two-Phase Flow Pattern of R-22, R-134a, and R-407C in a 6.5-mm Smooth Tube,” Exp. Thermal and Fluid Science, Vol.15, pp.
395-405, 1997.
3.C. S. Kuo, and C. C. Wang, “Horizontal Flow Boiling of R22 and R407C in a 9.52 mm Micro-Fin Tube,” Applied Thermal Engineering, Vol.16, pp.719-731, 1996.
4.D. Chisholm, “Pressure Gradients due to Friction During the Flow of Evaporating Two-Phase Mixtures in Smooth Tubes and Channels,” Int. J. Heat Mass Transfer, Vol.16, pp.347-358,
1973.
5.J. A. Tichy, J. Duque-Rivera, N. A. Macken, and W. M. B. Duval, “An Experimental Investigation of Pressure Drop in Forced-Convection Condensation and Evaporation of Oil-Refrigerant Mixtures,” ASHRAE Transactions, Vol.92, Part 1, pp.461-472, 1986.
6.J. G. Collier, and J. R. Thome, “Convective Boiling and Condensation,” 3rd Ed., Ch2, McGraw-Hill, New York, 1994.
7.K. Hashizume, “Flow Pattern, Void Fraction and Pressure Drop of Refrigerant Two-Phase Flow in a Horizontal Pipe─Part Ⅰ,” Int. J. Multiphase Flow, Vol.9, No.4, pp.399-410, 1983a.
8.K. Hashizume, “Flow Pattern and Void Fraction of
Refrigerant Two-Phase Flow in a Horizontal Pipe,” Bull. JSME, Vol.26, No.219, pp.1597-1602, 1983b.
9.K. Seo, and Y. Kim, “Evaporation Heat Transfer and Pressure Drop of R-22 in 7 and 9.52 mm Smooth/Micro-fin Tubes,” Int. J. Heat Mass Transfer, Vol.43, pp.2869 -2882, 2000.
10.L. Friedel, “Improved Friction Pressure Drop Correlations for Horizontal and Vertical Two-Phase Pipe Flow,” Presented in European Two-Phase Flow Group Meeting, Ispra, Italy, Paper E2, June 1979. (Paper reviewed in Ref.[6])
11.L. M. Schlager, M. B. Pate, and A. E. Bergles, “A Survey of Refrigerant Heat transfer and Pressure Drop Emphasizing Oil Effects and In-Tube Augmentation,” ASHRAE Transactions, Vol.
93, Part 1, pp.392-416, 1987a.
12.L. M. Schlager, M. B. Pate, and A. E. Bergles,
“Evaporation and Condensation Heat Transfer and Pressure Drop in Horizontal, 12.7-mm Microfin Tubes with Refrigerant 22,” Journal of Heat Transfer-Transactions of the ASME, Vol.112, pp.1041-1047, 1990.
13.L. M. Schlager, M. B. Pate, and A. E. Bergles, “Performance Predictions of Refrigerant-Oil Mixtures in Smooth and Internally Finned Tubes─Part Ⅰ: Literature Review,” ASHRAE Transactions, Vol.96, Part 1, pp.160-169, 1990.
14.L. M. Schlager, M. B. Pate, and A. E. Bergles, “Performance Predictions of Refrigerant-Oil Mixtures in Smooth and Internally Finned Tubes─Part Ⅱ: Design Equations,” ASHRAE Transactions, Vol.96, Part 1, pp.170-182, 1990.
15.N. Kattan, J. R. Thome, and D. Favrat, “Flow Boiling in Horizontal Tube: Part 1─Development of a Diabatic Two-Phase Flow Pattern Map,” Journal of Heat Transfer-Transactions of the ASME, Vol.120, pp.140-147, 1998.
16.N. Z. Azer, and V. Sivakumar, “Enhancement of Saturated Boiling Heat Transfer by Internally Finned Tubes,” ASHRAE Transactions, Vol.90, Part 1A, pp.58-73, 1984. (Paper reviewed in Paper reviewed in Ref.[13])
17.O. Zürcher, D. Favrat, and J. R. Thome, “Development of a Diabatic Two-Phase Flow Pattern Map for Horizontal Flow Boiling,” Int. J. Heat Mass Transfer, Vol.45, pp.291-301, 2002.
18.R. J. Moffat, “Describing the Uncertainties in Experimental Results,” Exp.Thermal and Fluid Science, Vol.1, pp.3-17, 1988.
19.R. W. Lockhard, and R. C. Martinelli, “Proposed Correlation of Data for Isothermal Two-Phase Two-Component Flow in Pipes,” Chem. Eng. Prog., Vol.45, pp.39-48, 1949. (Paper reviewed in Ref.[6])
20.S. E. Haaland, “Simple and Explicit Formulas for the Friction Factor in Turbulent Pipe Flow,” J. Fluids Eng.-Transactions of the ASME, Vol.105, No.1, pp.89-90, 1983.
21.S. J. Eckels, T. M. Doerr, and M. B. Pate, “Heat Transfer Coefficients and Pressure Drops for R-134a and an Ester Lubricant Mixture in a Smooth Tube and a Micro-Fin Tube,” ASHRAE Transactions, Vol.104, No.1A, pp.366-375, 1998a.
22.S. S. Hsieh, K. J. Jang, and Y. C. Tsai, “Evaporation Heat Transfer and Pressure Drop in Horizontal Tubes with Strip-Type Inserts Using Refrigerant 600a,” Journal of Heat Transfer-Transactions of the ASME, Vol.122, pp.387-391, 2000.
23.潘欽 (C. Pan)著, “沸騰熱傳與雙相流,” 初版, 第九章, 國立編譯館, 台北市, 2001.
24.涂世昇 (S. S. Twu), “R141b冷媒在水平玻璃管內的流動沸騰研究,” 國立清華大學工程與系統科學研究所碩士論文, 1999.