FLOW REGIME IDENTIFICATION OF STEAM-WATER FLOW IN A LARGE VERTICAL PIPE AT ELEVATED PRESSURES

摘要

Analysis of experimental data on steam-water two-phase flow in arnlarge diameter (61.0 cm O.D., and 50.8 cm I.D.) vertical pipe atrnelevated pressures and temperatures (2.8MPa/230℃ -rn6.4MPa/280℃) has been performed. Void fraction fluctuationrncharacteristics were used to identify the flow regimes existingrnunder different flow conditions. Based on the flow regime mapsrndeveloped, the slug flow , as traditionally defined, was not existentrneven under conditions where it normally occurs in small diameterrnvertical pipes.rnThe average void fraction data were correlated in the formrnof a drift flux correlation in order to obtain the distributionrnparameter and average drift velocity. The correlated data were thenrncompared with existing correlations recommended for two-phasernflow in large diameter pipes.