Effect Of Tandem Dislocation Blade On Inter-Nal Flow Field And Pressure Fluctuation Characteristics Of Multiphase Pump

With the increasing demand for fossil energy,the development of deep-sea oil and air resources has become a breakthrough in energy shortage.As an important equipment for exploiting deep-sea oil and air resources,the performance and stability of multiphase pump affects the efficiency of oil and air resources development.Due to harsh seafloor environment and complex oil and air two-phase media,the performance of multiphase pump is affected,even threatening the safe and stable operation of the unit.In this paper,a multiphase pump is used as a prototype pump to improve the performance and stability of the pump by modifying the blades.The blades of the impeller are interrupted in the middle of the impeller,and the whole blade of the rear half rotates clockwise on the axial direction of the pump shaft.The rotated angle is defined as the angle of the tandem dislocation blades.The air-liquid two-phase flow characteristics and hydrodynamic characteristics of the mixed pump with different tandem dislocation blade angles were investigated by combining numerical simulation and experiment.The main research contents and conclusions are as follows:(1)In order to explore the influence of the tandem dislocation blade angles in series on the performance and stability of multiphase mixed pump,the influence of tandem dislocation blades on the external characteristics of the pump under pure liquid condition was obtained by combining numerical simulation and experimental research.It was found that the head of the mixed pump near the rated flow rate is higher when the tandem dislocation blade angle is 45 degrees,and the internal flow field and pressure fluctuation were analyzed.It is found that the tandem dislocation blade structure can improve the boosting performance of front blade in the(2)In order to study the influence of gas content on the performance and stability of tandem dislocation blade mixed pumps with different series arrangement under gas-liquid two-phase condition.By means of numerical simulation,the influence rule of tandem dislocation blades on the external characteristics of the mixed pump under gas-liquid two-phase condition is obtained.It is found that the head of the mixed pump is higher near the low gas content when the tandem dislocation blade angle is 45 degrees.Through analysis of the internal flow field and pressure fluctuation,it is found that when the tandem dislocation blade angle is 45 degrees,the blade can effectively interrupt the high gas content area in the flow channel and uniformly distribute the gas in the flow channel.Compared with the original mixed pump,the turbulent energy change of the mixed pump is the smallest when the tandem dislocation blade angle is 45 degrees,and the amplitudes of non-blade frequency and the frequency multiplication of the blade frequency are smaller under the condition of high air content,which has better stability.In this paper,the influence mechanism of tandem dislocation flow path on flow pattern in mixed pump is revealed,and the influence rule of angle and air content of tandem dislocation blade on flow pattern in mixed pump is clarified,which has certain guiding significance for actual engineering.