Study Of Liquid Viscosity Effect On Performance Of Electrical Submersible Pump(ESP) Based On Simulation And Experiment

Submersible electric pumps are an important type of mechanical oil extraction equipment used in oil fields.Pump performance tests were all measured using water as the medium.However,the pump in the oil field conveys a viscous medium mixed with oil and gas.This can cause the field operating parameters to be inconsistent with the parameters on the nameplate,which is not conducive to the evaluation of the actual working performance of the electric submersible pump.In addition,to ensure its stable and reasonable operation,the submersible pump often uses the variable frequency control technology to adjust the off-design condition and control production.Therefore,it is of great significance to study the performance curves and internal flow field of the submersible electric pump with different viscosity liquids as medium under variable flow conditions and different rotational speeds.In this paper,submersible pumps are tested for the performance of liquids with different viscosity.By analyzing the experimental data and plotting the efficiency,head and shaft power curves of the submersible pump under different viscosities,and using Excel 2016 for regression analysis,the influence of viscosity changes on the pump hydraulic performance was studied.In the software ANSYS CFX,the single stage submersible pump under different flow conditions is simulated.The simulation results are compared with the experimental data.The overall error does not exceed 7% except for small individual errors in small flow conditions.These results verify the reliability of numerical simulations.In addition,the variable speed conditions are combined to analyze the effects of viscosity on the hydraulic efficiency,head and shaft power of submersible pumps under variable frequency control.The static pressure distribution and velocity vector distribution of the submerged electric pump's internal flow field are analyzed,which reveals the internal flow mechanism of the submersible electric pump under variable flow conditions and variable speed conditions under different viscosity media.The results of the research on the external characteristics and internal flow field of the submersible electric pump showed that the shaft power increased with the increase of the viscosity of the liquid pumped by the pump under the same flow conditions.In contrast,head and efficiency decrease as the viscosity increases.Under large flow conditions,the liquid generates a detachment and vortex at the leading edge of the blade,and the fluid loss in the pump is greater.From the performance curve of the pump at different speeds,as the speed increases,the lift and power increase gradually,and the peak efficiency at each speed condition also increases with the increase of the speed,which verifies the proportionality law.Under high efficiency conditions,the distribution of the flow field under different rotational speeds of the submersible pump is similar,but the pressure field and velocity field in the local area still differ with the change of the rotational speed.The above research results provide theoretical basis and technical guidance for the effectof liquid viscosity on the submersible electric pump,which has certain guiding significance for the actual operation of the pump.