A Study on Local Flow Patterns of Fas-liquid Two-phase Cross Flow in Vertical Tubes

摘要

The upward non-boiling multiphase cross flow and heat transfer in the vertical tube occurs widely in oil production and chemical facilities, but it draws little attention. In this study, the local flow patterns of an upward gas-water two phase cross flow in a vertical tube were investigated with an optical probe and the visualization of digital high speed video system. The local flow patterns in cross flow are firstly defined as bubble, slug, churn and annular flow patterns. Optical probe signals are analyzed in probability density function, and it is proved that the local flow patterns can be recognized by this method. The transition mechanisms between the different flow patterns have been analyzed theoretically and the corresponding transition models are proposed. Finally local flow pattern maps of the upward gas-water two-phase cross flow in the vertical tube are also firstly constructed.