Development and optimization of a two-phase flow pump and separator system

Abstract

This paper describes the results of a study on the development and the optimization of a twophase flow pump and separator system. This system must be lightweight, compact and efficient and has to extract the gas out of the two-phase flow and transmit energy into the liquid only. Prototypes of different designs are tested at ULB on a specific test bench using water and air. The current prototype is a helical-centrifugal pump. The axial part is used to separate the two phases of the flow and to collect, in the centrifugal part, the liquid phase only. Different tests were performed to visualise the flows, to study the prototype performances and to understand how to improve them. The positive aspect of this prototype is its high separation efficiency over a wide range of flow rates and liquid-to-gas ratios. On the other hand, the pumping performance has to be improved. The study deals also with the development of a visualization technique to measure the gas/liquid ratio at the outlet of the system. Photos of the two-phase flow are taken at the system outlet and processed with a specific software to determine the proportion of air in the water flow. At the same time, the flow field in the pump and separator system is being studied with two commercial CFD (computational fluid dynamics) software packages: Fluent and STAR-CD. Before starting two-phase flow simulations, a comparison of these two codes was made with a single-phase and incompressible fluid model.SCOPUS: cp.pinfo:eu-repo/semantics/publishe