Flow Pattern and Void Fraction of Refrigerant Two-phase Flow in a Horizontal Pipe

Abstract

An experiment on a refrigerant two-phase flow in a horizontal pipe was performed for flow pattern observation and void fraction measurement. Refrigerants used were R12 and R22, and the saturation pressure range was from 5.7 to 19.6 bar. From obtained data it was found that the flow pattern of the refrigerant two-phase flow can be presented on a revised Baker map, where the property correction factor on surface tension was modified. It was also found that the influence of the shut-off speed in void fraction measurement is negligible. Experimental data on void fraction agree well with Zivi, Thom and Baroczy correlation approximated by Butterworth.