Abstract
An investigation on the high-quality dryout in two electrically heated coiled tubes with horizontally helix axes is reported. The temperature profiles both along the tube and around the circumference are measured, and it is found that the temperature profiles around the circumference are not identical for the cross-sections at different parts of the coil. The “local condition hypothesis” seems applicable under present conditions, and the critical heat fluxq crdecreases with increasing critical qualityx cr. The CHF increases as mass velocity and ratio of tube diameter to coil diameter (d/D) increases, and it seems not to be affected by the system pressure. The CHF is larger with coils than that with straight tubes, and the difference increases with increasing mass velocity andd/D.
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References
G. Berthoud and S. Jayanti, “Characterization of Dryout in Helical Coils,”Int. J. Heat Mass Transfer,33, No.7, pp.1451–1463, (1990).
K. Jensen and A.E. Bergles, “Critical Heat Flux in Helically Coiled Tubes,”Trans. of ASME,103, pp.660–666, (1981).
M.K. Jensen and A.E. Bergles, “Critical Heat Flux in Helical Coils with a Circumferential Heat Flux Tilt Toward the Outside Surface,”Int. J. Heat Mass Transfer,25, No.9, pp.1383–1395, (1982),
I.I. Gromova and V.N. Smolin, “Burnout Heat Transfer in Steam Generating Channels under Steady and Unsteady Conditions,”Heat Transfer-Soviet Research,24, No.5, pp.603–611, (1992).
M. Cumo, G.E. Farello and G. Ferrari, “The Influence of Curvature in Post Dry-out Heat Transfer,”Int. J. Heat Mass Transfer,15, pp.2045–2062, (1972).
T.K. Chen, Q.C. Bi and X.J. Chen, “Critical Heat Flux and Post CHF Heat Transfer of Steam Water two Phase Flow in Helical Coil Tubes,” Proc. 3rd Int. Conf. of Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Hawaii, U.S.A. Oct. (1993).
X.J. Chen and C.J. Tu, “Characteristics of Flow and Heat Transfer in Steam Generators of Helically Coiled Tubes,”Nulear Power Engineering (in Chinese),3, No.5, (1982).
A. Owhadi, et al., “Forced Convection Boiling Inside Helically-Coiled Tubes,”Int. J. Heat Mass Transfer,11, pp.1779–1793, (1968).
H.C. Unal, “Determination of Void Fraction, Incipient Point of Boiling, and Initial Point of Net Vapor Generation in Sodium-Heated Helically Coiled Steam Generator Tubes,”Trans. of ASME,100, pp.268–274, (1978).
P.B. Whalley, “Air-Water Two-Phase Flow in a Helically Coiled Tube,”Int. J. Multiphase Flow,6, pp.345–356, (1980).
F.D. Zhou, “Investigation on Steam Water Two-Phase Flow and Transfer Inside Helically Coiled Tubes (in Chinese),” Ph.D. Dissertation, Xi’an Jiaotong University, China, (1985).
L.J. Guo, “Dynamic Characteristics of Vapor (Air) Water Two-Phase Flow in Horizontal Helical Coils (in Chinese),” Ph.D. Dissertation, Xi’an Jiaotong University, China, (1989).
O. Watanabe, K. Nakajima, H. Fujita, “Characteristics of Liquid-Film Thickness of Air-Water Annular Two-Phase Flow in Helically Coiled Tubes,”Heat Transfer-Japanese Research, 22, No.5, (1993).
K. Moribumi, “Film Thickness and Flow Boiling for Two-Phase Annular Flow in Helically Coiled Tubes,” Int. Meeting on Reactor Heat Transfer, Paper No.16, Germany, (1973).
O. Watanabe, N. Heya, et al., “Low-Quality Dryout in Horizontal Helical Coiled Tubes,”Heat Transfer-Japanese Research, 22, (1993).
K. Stephan, «Heat Transfer in Condensation and Boiling», Translated by C. V. Green, Springer-Verlag Berlin Heidelberg, pp.236–238, (1992).
J.G. Collierm and J.R. Thome, «Convective Boiling and Condensation», Clarendon Press, pp.339–353, (1994).
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Ma, W., Zhang, M. & Chen, X. High-quality critical heat flux in horizontally coiled tubes. J. of Thermal Science 4, 205–211 (1995). https://doi.org/10.1007/BF02650830
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DOI: https://doi.org/10.1007/BF02650830