Three-dimensional Unsteady Constant Value Simulation Of The Full Flow Channel Of The Reversible Pump Turbine

During the operation of the pump or turbine of the pumped storage power station,the water pressure,the water flow and the rotational speed will cause complicated changes during the normal operation,start,stop and load rejection of the turbine or water pump,and cause the hydraulic vibration,the mechanical vibration or the parts Stress change.In order to study these phenomena,CFD numerical simulation is used to model the geometrical model of pump turbines in a storage power station.The RNG K-? model and SIMPLE algorithm are used to calculate the rated flow Qr,0.19Qr,0.473Qr,0.655 Qr,0.82Qr and 1.2Qr conditions and water pump conditions,the data of the internal flow field of the pump turbine are obtained,and the distribution and variation of the internal flow field of the pump turbine are analyzed by the processing of the post-processing software.The At the same time,the pressure fluctuation between the volute inlet,the movable guide vane,between the guide vane and the runner,and the pressure pulsation of the straight cone and the elbow of the draft pipe are analyzed to analyze the pressure pulsation of each part of the pump turbine Domain distribution and frequency domain distribution.The results show that the pressure in the spiral case of the pump turbine is descending from the static pressure in the outward direction.With the increase in the opening of the guide vane,the overall pressure of the volute is reduced.The activities of the guide vane import head and the activities of the guide vane of the imported head have a strong static pressure concentration.At 0.655Qr flow conditions,the circumferential flow in the volute of the pump turbine and the circumferential flow in the volute section are very disturbing.In the small flow conditions such as 0.19Qr and 0.473Qr,the jet is formed at the outlet of the guide vane,and the vortex structure is formed near the inlet edge of the guide vane and the runner.The opening of the guide vane is increased,the jet is weakened,the flow field of the leafless area tends to be gentle and the vortex structure disappears near the inlet edge of the blade.In the case of the runner structure,the high pressure red area is mainly concentrated in the head of the inlet of the runner blade,the inlet side of the lower ring of the wheel and the area near the transfer position of the blade.As the output increases,The high pressure zone extends from the inlet of the blade to the edge of the blade.When the deviation from the optimal working conditions is far away,the large entrance angle will cause the water flow in the rotor blade head dewatering phenomenon,the formation of vortex structure into the runner blades flow between the formation of leaf vortex.In the pump case,the flow direction of the flow and the direction of the turbine flow in the opposite direction,by the runway leaves the water flow directly hit the guide vane,to the activities of the guide vane to bring a great impact in the guide vane flow channel to form a strong Turbulence perturbation and vortex structure,the volute in the volute is also a special disorder and are accompanied by the phenomenon of secondary reflow.The tailrace vortices are intertwined with each other,and the vanes are affected by the high frequency ripple by the static and static interference.The tailrace area is affected by the low frequency pulsation of the tailrace vortex and propagated upstream and downstream.The fluctuation frequency of leafless leaves between leaf and runner is constant,and the amplitude of each frequency increases with the increase of load.