8.8. Observations

The post-CHF heat transfer regime has been summarized with three different approaches to estimate the heat transfer coefficient. We would recommend the empirical equilibrium or non-equilibrium approach for an estimate of post-CHF heat transfer rates. However, if the wall temperature and degree of superheat (or heat flux for the other boundary condition) are of crucial importance of semi-theoretical approach might be considered for detail analysis. This latter recommendation will require new data for specific geometries to determine the droplet-gas and droplet-wall heat transfer rates accurately.

References

• H. Amm and G. Ulrych, "Comparison of Measured Heat Transfer Coefficients During Reflooding a 340-rod Bundle and Those Calculated From Current Heat Transfer Correlations." Paper E7, European Two-Phase Flow Meeting, Harwell, 1974.
• A.W. Bennett, "Heat Transfer to Mixtures of High Pressure Steam and Water in an Annulus." AERE-R4352, 1964.
• R.G. Bressler, "A Review of Physical Models and Heat Transfer Correlations for Free Convection Film Boiling." Adv Cryogenic Engr, 17, 382-406, 1972.
• L.D. Clements and C.P. Colver, "Natural Convection Film Boiling Heat Transfer," Indstr. Engr Chem 62(9), 26-46, 1970.
• A.F. Course and H.A. Roberts, "Progress With Heat Transfer to a Steam Film in the Presence of Water Drops - a First Evaluation of Winfrith SGHWR Cluster Loop Data," AEEW-M1212. Paper presented at European Two-Phase Flow Group Meeting, Harwell, 1974.
• G.C. Gardner, "Evaporation and Thermophertic Motion of Water Drops Containing Salt in a High Pressure Steam Environment." Paper presented at European Two-Phase Flow Conference, Harwell, England, 1974.
• E.M. Greitzer and F.H. Abernathy, "Film Boiling on Vertical Surfaces." Int J Heat Mass Transfer, 15, 475-491, 1972.
• D.C. Groeneveld, "Effect of a Heat Flux Spike on the Downstream Dryout Behaviour," J of Heat Transfer, 121-125, 1974.
• D.C. Groenveld, "Post-Dryout Heat Transfer at Reactor Operating Conditions." AECL-4513. Paper presented at the Nat Topical Meeting on Water Reactor Safety, ANS, Salt Lake City UT, 1973.
• Y.Y. Hsu, "Review of Film Boiling,"Adv in Cryogenic Engr 17, 361-381, 1972.
• P. Hutchinson, G.F Hewitt and A.E. Dukler, Chem Eng Sci 26, 419, 1971.
• O.C. Iloje, D.N Plummer, W.M. Rohsenow, P. Griffith, "A Study of Wall Rewet and Heat Transfer in Dispersed Vertical Flow."MIT Dept of Mech Engr Report , 72718-92,1974.
• D.N. Plummer, O.C. Iloeje, W.M. Rohsenow, P. Griffith and E. Ganic, "Post Critical Heat Transfer to Flowing Liquid in a Vertical Tube." MIT Dept of Mech Engr Report 72718-91, 1974.
• P.S. Rao and P.K. Sarma, "Partial Evaporation Rates of Liquid Particles on a Hot Plate Under Film Boiling Conditions," Con J of Chem Engr, 52 (3), 415-419, 1974.
• L.S. Tong, "Film Boiling Heat Transfer at Low Quality of Subcooled Region." Proceedings 2nd Joint USAEC-EURATOM Two-Phase Flow Meeting, Germantown. Report CONF-640507, p 63, 1974.
• G.B. Wallis and J.G. Collier "Two-Phase Flow and Heat Transfer." Notes for a Summer Course, July 15-26, Thayer School of Engineering, Dartmouth College, Hanover, NH, USA. III, 33-46, 1968.
• P.B Whalley, P. Hutchinson and G.F. Hewitt, "The Calculation of Critical Heat Flux in Forced Convection Boiling," AERE-R7520, 1973.