Numerical Study And Energy Saving Analysis Of Electric Submersible Pump Internal Flow Field Characteristics Under Variable Frequency Speed Regulation Condition

With oilfield development has entered into the middle-later period, reservoir pressure change is larger, so as to maintain formation pressure, water injection rate is increased. Therefore, it is frequently necessary for electric submersible pump to be run efficiently under off-design conditions, and variable-frequency regulating speed technology can well meet the requirements, use CFD technology to research internal flow field numerical experiments, for variable frequency control technology is better applied to electric submersible pump, and analyze energy saving of variable frequency speed regulation.Choose a type of electric submersible pump as the research object, the impeller and guide vane overflowing part are extracted as three dimensional flow field, structured grids are divided. Determine fluid dynamics model and calculation methods. CFD technology is used to calculate internal flow field numerical value for variable flow and speed of electric submersible pump. According to post-processing calculating data, the pressure field, velocity field, other nephogram and external characteristic curve of impeller and guide vane were obtained. And the electric submersible pump hydraulic performance change rule were researched under the variable flow and variable speed operation conditions.Under off-design conditions, the internal flow field research results show that: the loss of impeller and guide vane flow channel is higher under off-design condition, and the pump efficiency is highest under design condition. The internal flow field structure is close under various rotate speed condition of high efficient workspace, but the pressure and velocity field will change along with the speed changes. The flow field simulation results under nozzle adjustment and variable frequency regulation condition show that: The internal flow field hydraulic performance is better through variable frequency regulation compared to nozzle adjustment condition, the hydraulic loss is smaller. Under the nozzle adjustment condition, in the pump passageway appear hindering fluid flow, and the loss is bigger, so compared with nozzle adjustment, the frequency conversion adjustment can save energy and improve the pump efficiency.The research result in this paper, for the promotion and application of electric submersible pump optimization design and variable-frequency regulating speed technology, it provides a theoretical basis and technical guidance.