Investigation of the fluid dynamic and thermodynamic behaviour of multiphase screw pumps handling liquid/gas mixtures with very high gas volume fractions

摘要

The conveyance of multiphase fluids with very high gas volume fractions (GVF's) by means of multiphase screw pumps represents a challenging task. The correct prediction of the pump characteristics and temperature distribution inside the pump at GVF's from 90 % up to the loss of prime is very important. In this research, the most significant part of a new screw pump model is presented. This model deals with the compressibility, acceleration and heat transfer effects of the two-phase mixture inside the internal clearances. It is used to predict the decrease of the volumetric flow rate at very high GVF's. Furthermore a finite volume based CFD programme was developed to enable the calculation of the two-phase flow through all clearances, using the homogeneous equilibrium model.