Abstract
This paper takes a pump-turbine as the research subject and, based on the Computational Fluid Dynamics (CFD) numerical method and combined with test data, investigates the pressure fluctuation characteristics in the pump mode and analyzes the pressure fluctuation characteristics at 0.75 Qd, 1.0 Qd and 1.25 Qd when the guide vane opening is 17.5°. The results showed that the protruding frequencies of pressure fluctuation in the bladeless region were mainly 5 fn, 10 fn and 20 fn, and the main frequencies in the runner area and near the outlet wall of the draft tube were 16 fn and 5 fn, respectively. At different heights for the guide vanes, the pressure fluctuation in the bladeless region had significant differences, and the pressure fluctuation near the bottom ring was the most intense. The amplitude of the rotor–stator interaction frequency continuously attenuates from the bladeless region to the outlet of the stay vanes, and the amplitude attenuation of each frequency is mainly concentrated in the area of the guide vanes. In this paper, the influence of different flow rates on the pressure fluctuation in the pump mode is analyzed, which provides a theoretical reference for the stability and further study of pump-turbines.
Highlights
The pumped storage power station plays a few important roles in the power system, such as peak load regulating, emergency standby and directional service
It can be seen from the table that the protruding frequencies of the pressure fluctuation in the bladeless region were 10 fn, 20 fn, and 5 fn, in descending order according to the amplitude, which was the same as the theoretical prediction of the rotor–stator interaction frequency above, indicating that the pressure fluctuation in the bladeless region is mainly caused by rotor–stator interaction
With the increase of flow, the pressure fluctuation inside the runner decreased gradually, and the strong fluctuation region was mainly concentrated in the pressure surface at the trailing edge of the splitter blades
Summary
The pumped storage power station plays a few important roles in the power system, such as peak load regulating, emergency standby and directional service. A runner with splitter blades has gradually been recognized to play an important role in reducing pressure fluctuations and improving cavitation performance. Foreign and domestic scholars, using computational fluid dynamics and the fluid–structure interaction numerical calculation method for analysis of the internal flow of the pump-turbine, have sufficient cognition about its mechanism and give relevant improvement measures [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. The pressure fluctuation characteristics of the pump-turbine with splitter blades under different flow rates are analyzed based on the CFD numerical calculation method and combined with relevant test data, which provides certain theoretical reference for the design and improvement of pump-turbines
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
