Numerical analysis of the hydraulic force of a pump turbine under partial load conditions in turbine mode

29th IAHR Symposium on Hydraulic Machinery and Systems

Wang, L.K.^1 ; Lu, J.L.^1 ; Liao, W.L.^1 ; Zhao, Y.P.^1 ; Ji, Q.F.^1

Institute of Water Resource and Hydro-electric Engineering, Xi'An University of Technology, Xi'an, China^1

关键词: Deviation coefficient;    Discharge conditions;    Low frequency pressure;    Noise and vibration;    Pressure fluctuation;    Pressure pulsation;    Pumped storage power station;    Unsteady numerical simulations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/7/072041/pdf
DOI  :  10.1088/1755-1315/240/7/072041

来源: IOP

【 摘 要 】

The power grid demand keeps changing at any time, so the pump turbine often operates in partial load condition. The noise and vibration of the unit caused by hydraulic force have an adverse effect on the safe and stable operation of the power plant. In order to study the mechanism of hydraulic force, a model pump turbine of a pumped-storage power station was set as the research object in this paper, both the steady and unsteady numerical simulation were carried out to simulate the flow field and hydraulic force of pump turbine. Axial force will increase significantly when the unit overloaded, but it has almost no change at partial load conditions. And the axial force on the runner is mainly produced by the hub and shroud, while it can be ignored on the blade. The radial force increases sharply when the condition deviates from the rated operating point. The frequency of pressure fluctuation is 20fn which is caused by rotor stator. There is more low frequency pressure fluctuation at small discharge condition because of the flow separation. The amplitude and deviation coefficient increased. The heterogeneity of pressure pulsation leads to the increase of radial force at partial load condition.