Numerical analysis and performance experiment of electric submersible pump with different diffuser vanes number

Space diffuser is one of the most critical flow components in electric submersible pumps; its hydraulic design has the significant effects on the pump performance. In this paper, a typical electric submersible pump was chosen as the research object to study the influence of space diffuser vanes number, by means of numerical simulation and experimental test methods. Based on the same curve profile and same impeller, the diffuser vanes number was adjusted to three different schemes of 6, 7, and 8. Calculation domain was created based on single-stage pump model, and meshed by the high density of structured grids associating with grid independence analysis. The numerical simulations under multi-conditions were performed based on SST k-omega turbulence model and standard wall function. Through the comparisons of predicted pump performance, we found that the pump head is increasing slightly with the increase of vanes number under part-loading conditions. However, excessive vanes occupy more passage area, which leads to blockings and more hydraulic losses under over-loading conditions. The diffuser scheme with seven vanes matches the impeller very well with less hydraulic losses. The test results prove that this scheme has an excellent pump performance, both the single-stage head and efficiency are higher than the Chinese national standard.