Study On Influence Factors Of Hydraulic Characteristics In The Side Inlet/Outlet Of Qingyuan Reservoir

Pumped storage power station plays several different roles in peak load shaving,frequency modulation,phase modulation,emergency standby etc in the power system,and it is an indispensable adjustment tool in the effective modern power system.The inlet/outlet is an important part of the water delivery system in a pumped storage power station,and its design level is directly related to the safety and efficiency of the power station.Based on Qingyuan Pumped Storage Power Station,this paper studied the bidirectional hydraulic characteristics of side inlet/outlet combining the method of model experiments with numerical simulation.Qingyuan reservoir's side inlet/outlet experimental model was established.Then the hydraulic characteristics,such as head loss coefficient,velocity distribution and flow distribution,were measured using acoustic doppler velocimeters and piezometric tube under the condition of outflow and inflow.It was found that the hydraulic characteristics of the design scheme meet the requirements of hydraulics,but it still had room for further optimization.To get better hydraulic characteristics of inlet/outlet,at the same time to study the influence factor of hydraulic characteristics at the side inlet/outlet,the side inlet/outlet numerical model was established.For numerical simulation,GCI was adopted to study the convergence of the mesh,and the error by the density of mesh were assessed.Then this paper compared the results of numerical simulation with model experiments to verify the rationality and reliability of the numerical simulation.Through the method of numerical simulation,this paper studied the influence on side inlet/outlet hydraulic characteristics by the change of orifice height.The results showed that in the range of 8.7m to 9.6m,with the increase of orifice height,the head loss coefficient and the non-uniformity coefficient of the flow velocity in section of the trash rack gradually under the outflow and inflow conditions.After that,remaining unchanged in the body shape parameters,this paper studied the influence of the change of the tunnel slope on the hydraulic characteristics of the side inlet/outlet.It turned out that under the outflow conditions,when the tunnel slope was less than the vertical diffusion angle of the diffusion section,with the increase of the slope angle of the tunnel,the reverse velocity zone,the non-uniformity coefficient of flow velocity and the head loss gradually decreased.When the tunnel slope the was larger than the vertical diffusion angle of the diffusion section,with the increase of the tunnel slope,the range of the reverse velocity zone,the non-uniformity coefficient of the velocity and the head loss gradually increased.Under the inflow conditions,the various hydraulic characteristics don't change substantially with the change of the tunnel slope.