Numerical Study On The Modification Of The Diversion Chamber Of Gas-liquid Mixed Pump And The Internal Two-phase Flow Characteristics

With the rapid development of industry and technology,the demand for oil and natural gas resources is also increasing,and the difficulty in mining oil and natural gas is increasing.Deep-sea oil and gas resources have become the focus of national development.As the development of deep-sea development is limited by pressure,lift and gas-liquid mixing,more stringent requirements are imposed on the "gas-liquid mixed pump" for power components.In recent years,domestic and foreign scholars have made many achievements in the research and analysis of gas-liquid mixed-feed pumps.However,the problems of low efficiency of gas-liquid mixed pump in deep sea mining and small use range of gas content are still to be solved.In this paper,a new type of deep-sea multi-stage centrifugal gas-liquid mixed pump is used as the analysis object,and the research work of gas-liquid two-phase flow is carried out.The liquid phase uses water as the medium and the gas phase uses air as the medium.In this paper,the Eulerian-Eulerian heterogeneous flow model is used as the two-phase flow calculation model.The SST k-turbulence model is used for the liquid phase,and the gas-phase two-phase flow is calculated for the mixed pump model using the dispersed phase zero equation model.The different operating conditions of the mixed pump were studied.The external characteristics and the characteristics of the two-phase flow characteristics of the mixed pump under the non-operating condition were analyzed.The first stage and single stage pump of the mixed pump were operated in the third stage.The external characteristics and internal flow characteristics under the same working conditions are compared,explaining the nature of the influence of the interaction between the mixed pump stages on the performance of the pump stage.Aiming at the two-phase flow characteristics of the mixed pump,a measure of the reforming of the diversion chamber is proposed.Many modifications are proposed for this kind of measure.The numerical calculations are carried out under different working conditions for different schemes.Excellent retrofit solution.The external characteristics,gas phase distribution and turbulent kinetic energy of the pump model before and after the modification of the diversion chamber were compared and analyzed under the three-stage operating conditions.The results show that the changes of flow rate and gas content have different effects on the external characteristics and internal flow characteristics of the mixed pump,and the influence of gas content is more obvious than the flow rate.The first stage of the mixed pump in the third stage operation has higher external characteristics than the single stage pump,and the internal flow distribution law is also different.The analysis shows that the essence of the difference in performance is that the first stage of the three-stage pump is subjected to the second and third levels of work.By comparing and analyzing the external characteristics and internal flow characteristics of the mixed pump of different diversion chambers,the optimal modification scheme was selected.