| 摘要(英) |
In the recent years, most of investigations of two phase flow distribution in plate heat exchanger (PHE) were experimental study. Due to complexity of flow and thermal structure inside PHE, researchers used simpler flat/circular tubes to represent the real plate in PHE. This study used the Computational fluid dynamics software ANSYS FLUENT to model an industrial type of K050 chevron corrugation PHE and simulated the two phase flow distribution. Several effects were studied, including two phase flow, flow maldistribution, the operating condition and the direction of the inflow distributor.
This paper was divided into two parts. First, the air/water two phase flow was investigated for effect of various direction of air inflow distributor (12 clock, 3 clock, 4 clock, 5 clock, 6 clock and 9 clock) in the single channel PHE. Simulation results showed that the direction of 3, 4 and 6 clocks generated better flow distribution. At low Reynolds number (Rel =500), the case of 3 clock had the most uneven flow distribution, while better flow distribution was observed for the case of 6 clock. At medium Reynolds number (Rel =1500), all the three cases (3, 4, 6 clocks) improved their flow distribution with reduced standard deviation of flowrate. It can be concluded that the increase of the Reynolds number which transformed the flow into turbulent and improved the flow distribution across channels inside PHE. At the high Reynolds number (Rel =3000), the case of 4 clock had the best even flow distribution. Finally, consider the effects of the flow passages on the hot/cold sides and the pressure drop, air inflow at 4 clock of the distributor was recommended.
The second part was investigation for the improvement of two phase flow distribution in a 10-channel PHE with an inflow distributor. Numerical results showed that at the multi-channels PHE without the distributor, the flow must operated at higher Reynolds number in order to have better flow distribution. If the PHE operated under Reynolds number lower than 1500, the vapor-liquid distribution can very uneven.
With the inflow distributor added, the maldistribution of the vapor phase improved significantly. Yet the flow distribution of liquid phase only worked at low Reynolds number condition. As Reynolds number increased, the inflow distributor was not that effective for liquid flow distribution.
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| 參考文獻 |
Asano, H., Takenka, N., Fujii, T., Maeda, N. (2004), “Visualization and void fraction measurement of gas-liquid two phase flow in plate heat exchanger”, Applied Radiation and Isotopes 61: 707-713.
ANSYS (2009) “ANSYS Fluent user guide”, ANSYS. Inc.
ANSYS (2009) “ANSYS Fluent theory guide”, ANSYS. Inc.
Baroczy, C.J. (1966), “A systemic correlation for two phase pressure drop”, Chem. Eng. Progr. Symp. Ser. 62, 232–249.
Fritz, W. (1935), “Berechnung des maximal von dampfblasen”, Phys. Z., 36, 379.
Gradeck, M., Lebouche, M. (2000), “Two phase gas-liquid flow in horizontal channels”, Inter. J. Multiphase Flow 26: 435-443.
Gradeck, M., Lebouche, M. (2000), “Two phase gas-liquid flow in horizontal corrugated channels”, Inter. J, Multiphase Flow 26: 435-443.
Kim, N. H., Sin, T. R. (2006), “Two-phase flow distribution of air–water annular flow in a parallel flow heat exchanger”, Inter. J. Multiphase Flow 32: 1340–1353.
Lozano, A., Barreras, F., Fueyo, N., Santodomingo, S. (2008), “The flow in an oil/water plate heat exchanger for the automotive industry”, Applied Thermal Eng. 28: 1109–1117.
Marchitto, A., Devia, F., Fossa, M., Guglielmini, G., Schenone, C. (2008), “Experiments on two-phase flow distribution inside parallel channels of compact heat exchangers”, Inter. J. Multiphase Flow 34: 128–144.
Marchitto, A., Fossa, M., Guglielmini, G. (2012), “The effect of the flow direction inside the header on two-phase flow distribution in parallel vertical channels”, Applied Thermal Eng.g 36: 245-251.
Nilpueng, K., Wongwises, S. (2006), “Flow pattern and pressure drop of vertical upward gas–liquid flow in sinusoidal wavy channels”. Exp. Thermal and Fluid Science 30: 523–534.
Parvareh, A., Rahimi, M., Alizadehdakhel, A., Alsairafi, A.A. (2010), “CFD and ERT investigation on two-phase flow regimes in vertical and horizontal tubes”, Inter. Communications in Heat and Mass Transfer 37:304–311.
Sandra, C.K., Schepper, D., Heynderickx, G. J., Marin, G. B. (2008), “CFD modeling of all gas–liquid and vapor–liquid flow regimes predicted by the Baker chart”, Chemical Eng. J. 138: 349–357.
Vist, S., Pettersen, J. (2004), “Two-phase flow distribution in compact heat exchanger manifolds”, Exp. Thermal and Fluid Science 28: 209–215.
Vlasogiannis, P., Karagiannis, G., Argyropoulos, P., Bontozoglou, V. (2002), “Air-water two phase flow and heat transfer in a plate heat exchanger”, Inter. J. Multiphase Flow 28: 757-772.
王啟川（2007），熱交換器設計，五南圖書出版有限公司，台北市。
曾廣彬（2010），「板式熱交換器之流場模擬與流動分布不均勻態分析」，國立中央大學機械工程研究所，碩士論文。
孟繁宇（2011），「水-空氣在板式熱交換器內的流動觀察」，國立中央大學機械工程研究所，碩士論文。
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