Che-Yin Lee This email address is being protected from spambots. You need JavaScript enabled to view it.1, Hsin-Heng Huang2, Shi-Min Lee2 and Kwan Ouyang3
1Department of Mechanical and Electro-Mechanical Engineering, Tamkang University, Tamsui, Taiwan 251, R.O.C. 2Department of Aerospace Engineering, Tamkang University, Tamsui, Taiwan 251, R.O.C. 3Department of Marine Engineering, Taipei College of Maritime Technology, Taipei, Taiwan, R.O.C.
Received: August 5, 2014 Accepted: November 13, 2014 Publication Date: December 1, 2014
This study used numerical simulation to analyze the influence of different factors, such as vacuum degree, fill ratio and aspect ratio, on the heat transfer characteristics of low-watt thermosyphon in natural convection. The mass and energy source terms were added in the continuity and energy equation to simulate the exchanges between vapor and liquid phases. The comparison analysis of computed result and experiment data showed that the numerical model used in this study is appropriate to analyze the physical mechanism and heat transfer property of thermosyphon. The results confirmed that low vacuum degree and long evaporator characterize better thermal resistance. The optimal fill ratio was 60% when the vacuum degree was 35 torr and the aspect ratio was 11.8.
Keywords: Heat Pipe, Thermosyphon, Vacuum Degree, Fill Ratio, Aspect Ratio, Boiling Heat Transfer
REFERENCES
[1] Li, J., Lin, F. and Niu, G., “An Insert-Type Two-Phase Closed Loop Thermosyphon for Split-Type Solar Water Heaters,” Applied Thermal Engineering, Vol. 70, Issue 1, pp. 441 450 (2014). doi: 10.1016/j.applthermaleng.2014.05.019
[2] Reay, D. A. and Kew, P. A., Heat Pipes (5th ed.), Butterworth-Heinemann, New York (2006).
[3] Zhang, M., Lai, Y., Zhang, J. and Sun, Z., “Numerical Study on Cooling Characteristics of Two-Phase Closed Thermosyphon Embankment in Permafrost Regions,” Cold Regions Science and Technology, Vol. 65, Issue 2, pp. 203 210 (2011). doi: 10.1016/j.coldregions. 2010.08.001
[4] Schmidt, E., in: Proc. Instn. Mech. Engrs., Conf. ASME, London, pp. 361 363 (1951).
[5] Imura, H., Sasaguchi, K., Kozai, H. and Humata, S., “Critical Heat Flux in a Closed Two-Phase Thermosypon,” International Journal of Heat and Mass Transfer, Vol. 26, No. 8, pp. 1181 1188 (1983). doi: 10. 1016/S0017-9310(83)80172-0
[6] Noie, S. H., “Heat Transfer Characteristics of a TwoPhase Closed Thermosyphon,” Journal of Applied Thermal Engineering, Vol. 25, pp. 495 506 (2005). doi: 10.1016/j.applthermaleng.2004.06.019
[7] Kafeel, K. and Turan, A., “Axi-Symmetric Simulation of a Two Phase Vertical Thermosyphon Using Eulerian Two-Fluid Methodology,” Heat and Mass Transfer, Vol. 49, Issue 8, pp. 1089 1099 (2013). doi: 10.1007/s00231-013-1155-6
[8] ANSYS FLUENT, User Guide (Release 14.0) (2011).
[9] Lee, W. H. and Lyczkowski, R. W., “The Basic Character of Five Two-Phase Flow Model Equation Sets,” International Journal for Numerical Methods in Fluids, Vol. 33, Issue 8, pp. 1075 1098 (2000). doi: 10.1002/1097-0363(20000830)33:83.3.CO;2-X
[10] Fadhl, B., Wrobel, L. C. and Jouhara, H., “Numerical Modelling of the Temperature Distribution in a TwoPhase Closed Thermosyphon,” Applied Thermal Engineering, Vol. 60, Issue 1 2, pp. 122 131 (2013). doi: 10.1016/j.applthermaleng.2013.06.044
[11] Karthikeyan, M., Vaidyanathan, S. and Sivaraman, B., “Thermal Performance of a Two Phase Closed Thermosyphon Using Aqueous Solution,” International Journal of Engineering Science and Technology, Vol. 2, Issue 5, pp. 913 918 (2010).
We use cookies on this website to personalize content to improve your user experience and analyze our traffic. By using this site you agree to its use of cookies.