The optimal model of misaligned guide vanes for a particular pump–turbine

Abstract

When the Pump-turbine operates in the S-shaped curve, the difficulty in loading rejection process and unusual increase in water pressure will occur, which is caused by the machine vibration. Misaligned Guide Vanes(MGV) can improve the stability of pump-turbine in no-load condition. In order to explore the feasible and effective way of pre-opening guide vanes, four kinds of pre-opening programs are given for the full three-dimensional numerical simulation of flow analysis and the model test then should be performed for the optimal model. From the CFD calculations and the experiment result shows that: the number of the pre-opening guide vanes is not the more the better for improving the S characteristics and the way of symmetrical distribution of the guide vanes is better than the way of centralized distribution. Finally, the program of pre-opening 2#, 7#, 12#, 17# four guide vanes has the most effective mitigation of the S characteristics of the particular Pump-turbine, and the CFD simulation also shows the good agreement with the experimental data.