Advertisement

Korean Journal of Chemical Engineering

, Volume 21, Issue 1, pp 75–80 | Cite as

Prediction of critical heat flux (CHF) for vertical round tubes with uniform heat flux in medium pressure regime

  • W. Jaewoo Shim
  • Joo-Yong Park
Article

Abstract

The description of critical heat flux (CHF) phenomena under medium pressure (10 bar≤P≤70.81 bar) regime is complex due to the large specific volume of vapor and the effect of buoyancy that are inherent in the conditions. In this study, a total of 2,562 data points of CHF in uniformly heated round vertical tube for water were collected from 5 different published sources. The data consisted of the following parameter ranges: 93.7≤G (mass flux)≤18,580 kg/m2s, 0.00114≤D (diameter)≤0.03747 m, 0.008≤L (length)≤5 m, 0.26≤qc (CHF)≤9.72MW/m2, and-0.21≤L (exit qualities)≤1.09. A comparative analysis is made on available correlations, and a new correlation is presented. The new CHF correlation is comprised of local variables, namely, “true” mass quality, mass flux, tube diameter, and two parameters as a function of pressure only. This study reveals that by incorporating “true” mass quality in a modified local condition hypothesis, the prediction of CHF under these conditions can be obtained quite accurately, overcoming the difficulties of flow instability and buoyancy effects. The new correlation predicts the CHF data are significantly better than those currently available correlations, with average error 2.5% and rms error 11.5% by the heat balance method.

Key words

CHF (Critical Heat Flux) Dryout Burnout Heat Transfer Equipment 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Becker, K. M., Strand, G. and Osterdahl, C., “Round Tube Burnout Data for Flow Boiling of Water at Pressures Between 30 and 200 bar,” Royal Institute of Technology, Laboratory of Nuclear Engineering, KTH-NEL-14, Sweden (1971).Google Scholar
  2. Becker, K. M., “Burnout Data for Flow of Boiling Water in Vertical Round Ducts, Annuli, and Rod Clusters,” Aktiebolaget Atomenergie Report AE 177, Sweden (1965).Google Scholar
  3. Biasi, L., Clerici, G. C., Garribba, S. and Sara, R., “A New Correlation for Round tubes and Uniform Heating and its Comparison with World Data,”Energia Nucleare,14(9), 530 (1967).Google Scholar
  4. Casterline, J. E. and Matzner, B., “Burnout in Vertical Long Tubes with Uniform and Cosine Heater Using Water at 1000 psia,” Topical Report No. 1, TASK XVI, Columbia University (1964).Google Scholar
  5. Griffel, J., “Forced Convection Boiling Burnout for Water in Uniformly Heated Tubular Test Sections,” NYO-187-7, Columbia University (1965).Google Scholar
  6. Inasaka, F. and Nariai, H., “Evaluation of Subcooled Critical Heat Flux Correlations for Tubes with and without Internal Twisted Tapes,”Nuclear Engineering and Design,163, 225 (1996).CrossRefGoogle Scholar
  7. Jafri, T., Dougherty, T. J. and Yang, B., “Correlation of Critical Heat Flux for Uniform Tubes,” NURETH-7, 4, 3197 (1995).Google Scholar
  8. Jafri, T., “Interpretation and Analysis of the Vertical Round Tube Critical Heat Flux Data,” Ph.D. Thesis, Columbia University (1993).Google Scholar
  9. Katto, Y. and Ohno, H., “An Improved Version of the Generalized Correlation of Critical Heat Flux for the Forced Convective Boiling in Uniformly Heated Vertical Tubes,”J. Heat Mass Transfer,27(9), 1641 (1984).CrossRefGoogle Scholar
  10. Kim, H. C., Baek, W. P. and Chang, S.H., “Critical Heat Flux in Vertical Round Tubes at Low Pressure and Low Flow Conditions,”Nuclear Engineering and Design,199(1), 49 (2000).CrossRefGoogle Scholar
  11. Mishima, K. and Nishihara, H., “Effect of Channel Geometry on Critical Heat Flux for Low Pressure Water,”Int. J. Heat Mass Transfer,30(6), 1169 (1987).CrossRefGoogle Scholar
  12. Saha, P. and Zuber, N., “Point of Net Vapor Generation and Vapor Void Fraction in Subcooled Boiling,” Proceeding of the 5th Int. Heat Transfer Conference, Tokyo, Japan, pp. 175–179 (1974).Google Scholar
  13. Shah, M. M., “Improved General Correlation for Critical Heat Flux during Upflow in Uniformly Heated Vertical Tubes,”Heat and Fluid Flow,8(4), 326 (1987).CrossRefGoogle Scholar
  14. Shim, W. J. and Joo, S.K., “Development and Analysis of a Uniform CHF Database,”JIEC,8(3), 268 (2002).Google Scholar
  15. Shim, W. J., “On the Development of a Two-Phase Flow Meter for Vertical Upward Flow in Tubes,”Korean J. Chem. Eng.,14(6), 528 (1997).CrossRefGoogle Scholar
  16. Thompson, B. and Macbeth, R.V., “Boiling Water Heat Transfer Burnout in Uniformly Heated Round Tubes: A Compilation of World CHF Data with Accurate Correlations,” AEEW-R 356, United Kingdom Atomic Energy Authority (1964).Google Scholar

Copyright information

© Korean Institute of Chemical Engineering 2004

Authors and Affiliations

  1. 1.Department of Chemical EngineeringDankook UniversitySeoulKorea

Personalised recommendations