CFD Simulation Of Labyrinth Screw Pump For Transporting The Coal Water Slurry And The Preliminary Discussion Of The Pump's Wear Mechanism

The development of CWS technology and the characteristics of several kinds of CWS pump were briefly introduced, mainly introduced the characteristics and the development situation of the labyrinth screw pump. In order to find out the flow law of solid/liquid two-phase in the interior system, we choose MLB-170-0.5 as research object, the article applied FLUENT analysis software and RNGκ-εmodel to numerical simulating and simulation in a labyrinth screw pump interior flow field, the simulated result shows that pressure, velocity, volume fraction, turbulent intensity and shear stress in pump, the wear mechanism of the pump s interior was also preliminarily discussed.The flow law of solid/liquid two-phase in the labyrinth screw pump:Pressure from inlet to outlet is gradually increasing, the velocity distribution is the same in the middle of the spiral section, in the circumferential velocity with the decrease of the trunnion gradually increasing, in the rotor threaded slot place is the maximal; Solid volume fraction in different areas of the same radial radius is different, which increase gradually along the direction of the radius and achieve maximum in the screw slots of the stator; The strongest turbulent intensity was in the clearance of stator and rotor, in the stator and the rotor threaded slot root was relatively gentle; The shear stress near the wall of the stator and rotor is bigger, and which was produced by solid phase is bigger than water.The flow law of different solid volume fraction and diameter:In the same diameter, as the solid volume fraction increasing, the pressure increased, the velocity and turbulent intensity are unchanged, the shear stress of water decreased and the coal opposite; In the same solid volume fraction, as the diameter increasing, the pressure and turbulent intensity are unchanged, the velocity of the coal decreased, the shear stress of water increased and the coal opposite.Simulation results show that:Solid volume fraction is higher in the spiral stator and the particle velocity is opposite, according to the wear formula, we can preliminary forecast that the wear of the rotor is more serious, which needs higher request for the rotor materials and proceeding technology. We obtained the solid/liquid two-phase flow condition in the interior system through the numerical simulation, which provides basis for the further research of the pump.