Effect In Performance Of Helicon-axial Multiphase Pump By Varying Axial Clearance

On the basis of second generation prototype of the YQH-100, the inner flow field and external characteristics of oil-gas pump compression stage were simulated based on the Euler method of multi-fluid model for two phase turbulence flows in different inlet gas volume fraction by using CFX. By analyzing the pressure field, the velocity field and gas-liquid distribution, the internal flow characteristics of gas-liquid mixing medium in oil-gas mixture pump individual compression stage were discussed. The change on performance was studied, which is brought by varying rotor-stator axial clearance in single stage and axial spacing between compression stages.The inner flow field and external characteristics of both single stage and two stages were simulated at different rotor-stator axial clearances and axial spacing respectively. Internal and external character of single stage at four different clearances (10mm, 15mm, 20mm, and 30mm)and two stages at three different axial spacing(10mm,15mm,20mm) was stimulated in diverse inlet gas fraction. The effect on total head, efficiency and torque were analyzed according to the simulation result.The results show that varying axial clearance effect on total head torque and efficiency. Total head trend to decrease with too long clearance or too small clearance which intensifies the degree of liquid-gas separation. The longer clearance is, the smaller backflow among rotor and stator will be, which bring smaller torque of blades. Efficiency depend on the synthetically action of total head and torque. There is no significant law between the clearance and efficiency .The efficiency of compression stage is highest when the axial clearance is 15mm in four clearances being chosen. Varying axial spacing has effect on total head torque and efficiency. Total head trend to decrease with too long clearance or too small clearance. Torque of blades is varied little with changing axial spacing. The efficiency of compression stage is highest when the axial clearance is 15mm in four axial spacing being chosen.