Effect of System Pressure on Frictional Pressure Gradient in Vertical Upward Gas-Liquid Two-Phase Flow. Experimental Results on Pressure Drop for System Pressure from 0.3 to 20 MPa.

Abstract

In order to clarify the pressure effects on frictional pressure gradients in vertical upward gas-liquid two-phase flow, measurements of pressure gradients were made for a pressure range of 0.3∼20 MPa. Frictional pressure gradients for each system pressure were presented and it was revealed that the effects of superficial liquid velocity on the frictional pressure gradient gets smaller with increasing system pressure. Furthermore, the characteristic is clarified that there exist minimum values with increasing superficial gas velocity in the pressure range of 10∼20 MPa. Comparison of measured values of frictional pressure gradients with the correlations proposed by Lockhart-Martinelli and Chisholm were made and these correlations were found not to be valid for the data at high pressure conditions. A new correlation to predict friction pressure gradients was proposed.