Study of the separation characteristics of gas-liquid-solid multiphase flow in the impeller of a helical axial flow oil-gas pump

During oil and gas transportation, due to transport mixed media, phase separation is easy to occur, which reduces the efficiency of the multiphase pump and may cause 'gas blockage' in serious cases. In this paper, the self-designed single stage helical axial flow compression unit was used as the research object to explore the separation characteristics of the fluid medium in the impeller of the pump. Based on computational fluid dynamic (CFD), the Euler multiphase fluid model and the SST k-omega turbulence model were used to calculate the flow in impeller. By setting monitoring points in the flow channel, the force movement of bubbles and solid particles is analysed. The results show that the radial velocities of bubbles and solid particles suddenly change in the middle of the channel. By analysing the pressure on the impeller surface, the coincidence area and non-coincidence area are defined. The results show that in the overlapping area when lambda > 0.5, GVF is basically consistent with the inlet and the maximum GVF is 0.8. In the non-overlapping area, when lambda > 0.5, the maximum GVF is 1, indicating complete gas-liquid separation.