Abstract: Based on the N-S equation and k-ε standard turbulence model, the inner flow of a screw centrifugal pump is simulated to study the work capacity of the impeller. The velocity, pressure and concentration along the blade in the whole process are observed, the energy transfer of transmission medium produced by impeller is separated into the centrifugal force work, the airfoil lift work and the volume change with the concept of lift coefficient of airfoil and drag coefficient, the blade load coefficient is used to analyze working capability of each segment of screw centrifugal pump impeller by introduction of load coefficient of centrifugal force, load coefficient of lifting and volume load coefficient, and the effect of two phase flow medium on impeller working is also analyzed. The results show that fluid energy of screw centrifugal pump is primarily provided by helical segment, the helical segment in the front of the impeller play an important role in multistage energized, the solid-liquid flow in screw centrifugal pump is turbulent flow, and the solid and liquid phase flows with different velocities respectively because of being pushed by the impeller screw and centrifugal effect. As liquid phase is the primary phase, the energy conversion is mainly up to the change of liquid energy, the solid phase flows under the wrapped action of liquid, and solid energy is carried out through liquid indirectly. Large particle size of solid phase and the higher volume concentration of two phase flow are more advantageous to the liquid energy conversion in the two-phase flow, on the contrary, when the volume concentration is too high, it is not conducive to the liquid energy conversion.

Key words: Load factor, Numerical simulation, Profile Lines, Screw centrifugal pump, Work capacity