Large Diameter Tube Flooding Experiments at Elevated Pressures

Abstract

A series of air/water and steam/water flooding experiments were conducted to study the effects of pressure and inlet water flow rate on flooding conditions in a large diameter vertical tube. Flooding is defined as the phenomena that occurs when an annular film flow reversal takes place due to the momentum of a countercurrent flowing gas. These experiments were performed to compare air/water and steam/water flooding data under various conditions and develop an empirical correlation that can be used to describe flooding in a large diameter vertical tube. For these experiments a vertical stainless steel tube was used to obtain well-characterized data in a simple geometry. Tests were conducted by establishing an annular liquid film into the test section followed by injecting gas into the test section to induce flooding. Flooding is considered to occur once some amount of the annular film reverses flow direction. Tests were performed at four different pressures ranging from atmospheric to 45 psig, at three different water inlet flow rates and with various tests, ranging from 0% to nearly 100% flow reversal.

The data used for this work is important due to it being the first of its kind in a well characterized large-diameter tube. The data suggest that there is little dependency on test section pressure and inlet water flow rate on flooding curves when plotted as non-dimensional Kutateladze parameters. The steam/water and air/water data trended very closely, and a correction factor was able to be used to translate the steam/water data to match with the air/water data. This data and corresponding empirical correlations developed can be used to modify and improve existing reactor safety codes.