Numerical Investigation of the Performance of a Submersible Pump: Prediction of Recirculation, Vortex Formation, and Swirl Resulting from Off-Design Operating Conditions

Abstract

Like any other turbomachinery, it is essential that the hydraulic behavior and performance of mixed-flow pumps are evaluated way in advance prior to manufacturing. Pump performance relies heavily on the proper design of the intake structure. Intake structures should be accurately designed in order to minimize and avoid unnecessary swirl and vortex formations. Ensuring the optimum performance condition as well as predicting how a particular intake structure affects the efficiency of the pump often requires either physical model studies or theoretical evaluations. Unfortunately, physical models are costly, time-consuming, and site-specific. Conversely, design and performance predictions using a theoretical approach merely gives performance values or parameters, which are usually unable to determine the root cause of poor pump performance. This study evaluates the viability of using Computational Fluid Dynamics (CFD) as an alternative tool for pump designers and engineers in evaluating pump performance. A procedure for conducting CFD simulations to verify pump characteristics such as head, efficiency, and flow as an aid for preliminary pump design is presented. Afterwards, a multiphase simulation using the VOF approach is applied to compare the fluid dynamics between four different pump intake structures. A full-sized CFD model of the pump sump complete with the pump’s active components was used for the intake structure analysis in order to avoid scaling issues encountered during the reduced-scale physical model test. The results provided a clear illustration of the hydraulic phenomena and characteristic curves of the pump. A performance drop in terms of reduction in TDH was predicted across the various intake structure designs. The CFD simulation of intake structure provided a clear insight on the varying degree of swirl, flow circulation, and effect on pump efficiency between all four cases.

Numerical analysis of the internal flow and pressure pulsation characteristics of a submersible tubular electric pump device

“…The research methods mainly use CFD technology and model tests (Wang et al, 2019a;Munih et al, 2020;Yang et al, 2022a) to study the internal and external characteristics and pressure pulsation of the pump device. The three-dimensional steady numerical analysis and structural optimization of the flow field in each flow structure (Lu et al, 2018;Arocena et al, 2021;Sun et al, 2021) have achieved fruitful research results. Zhang et al (2014) investigated the three-dimensional turbulent flow and the pressure fluctuation in a submersible axial-flow pump by adopting the RNG k-ε turbulence model and the SIMPLEC algorithm, with which the pressure pulsation distribution of the impeller inlet and outlet was obtained (Ji et al, 2021).…”

Influence of Blade Exit Angle on the Performance and Internal Flow Pattern of a High-Speed Electric Submersible Pump

“…They investigated these using a combination of CFD and experimental methods, and it was found that the impeller vane outlet placement angle had a significant effect on the pump performance. Arocena et al [13] conducted a numerical study of the performance of submersible pumps. The prediction of backflow, vortex formation and cyclonic flow caused by off-design conditions was investigated using CFD simulations to verify the pump head, efficiency, flow rate and other characteristics derived in different inlet structure designs.…”

Hydraulic Performance Optimization of a Submersible Drainage Pump

“…The Taguchi method was a remarkable handy tool in optimizing the ESP. Arocena et al [29] designed and analyzed the intake structure of a submersible pump numerically. Wei et al [30] investigated the influence of impeller gap drainage width on the performance of a low-specific-speed centrifugal pump, and the results revealed that using a smaller gap width could significantly improve the performance.…”