Effects of Rotation Speeds on Electrical Submersible Pump Performance Under Two-Phase Flow

Abstract

Electrical submersible pumps (ESP) are a pump classification, which is typically connected to an application of transporting fluids located in submersible elevations into supply pipelines. These pumps type can be found in offshore oil and gas facilities and are often used as transfer pumps for liquefied natural gas (LNG) terminals. In multiphase applications such as in LNG transport, operational challenges from the presence of air pockets and bubbles present a cavitation and degradation risk to the pump components. This paper proposed a computer simulation model using CFD analysis in ANSYS Fluent to study the effects of multiphase flow (gas–liquid flow) on ESP while varying the rotational speed with constant flow rate and inlet gas volume fraction (IGVF). Flow rate and IGVF kept constant with 20 L\min and 1%, respectively, while rotation speed varied by 500, 900, 1500, 2000, and 2500 rpm. The CFD results show that at low rotation speeds a large gas pocket performed at impeller inlet. However, by increasing the rotation speed, this gas pocket collapses to bubbly flow at the impeller inlet which leads to losses in high kinetic energy and concentration of bubbles at the impeller outlet and volute.