Experimental analysis of the vibration on the draft tube of a Francis hydraulic turbine during operation at different power levels
Keywords:power plant, vibrations, vortex, dynamic stress analysis
Severe vibrations are present on the draft tube of a 95 MW hydraulic turbine operating at partial load. Frequent failures on structural elements of the power plant are produced, due to the hydraulic instability inside the draft tube; mainly when the machine operates at partial load. Pressure inside the draft tube and stress on the external draft tube wall were measured at several power levels to identify the power where the conditions are critical for the structure. Also, measurements were conducted at partial load with air injection over the stay vanes and pressure relief on the spiral case. It was found that air injection effectively reduced vibrations while the pressure relief on the spiral case did not produce any useful effect.
Z. Qian, J. Yang, W. Huai. “Numerical simulation and analysis of pressure pulsation in Francis hydraulic turbine with air admission”. Journal of Hydrodynamics. Ser. B. Vol. 19. 2007. pp. 467-472.
C. Nicolet, J. Arpe, F. Avellan. “Identification and modelling of pressure fluctuations of a Francis turbine scale model at part load operation”. 22nd IAHR Symposium on Hydraulic Machinery and Systems. 2004. Stockholm (Sweden). pp. 1-14.
H. Gunter, J. C. Zanutto, W. Ponge-Ferreira. “Hydraulic power plant machine dynamic diagnosis”. Shock and Vibration. Vol. 13. 2006. pp. 409-427.
G. Blommaert, J. E. Prenat, F. Avellan, A. Boyer. “Active control of Francis turbine operation stability”. Proceedings of the 3rd ASME/JSME Joint Fluids Engineering Conference. 1999. San Francisco (CA). pp. 1-8.
R. Susan-Resiga, T.C. Vu, S. Muntean, G.D. Ciocan, B. Nennemann. “Jet control of the draft tube vortex rope in Francis turbines at partial discharge”. 23rd IAHR Symposium. 2006. Yokohama (Japan). pp. 1-14.
R. Susan-Resiga, A. Bosioc, T. Milos, S. Bernad, S. Muntean, A. Stuparu, A. Baya, L.E. Antón. “Swirling flow apparatus and test rig for flow control in hydraulic turbines discharge cone”. 2nd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems. Timisora. Romania. 2007. pp. 24-26.
X. Escaler, E. Egusquiza, M. Farhat, F. Avellan, M. Coussirat. “Detection of cavitation in hydraulic turbines”. Mechanical Systems and Signal Processing. Vol. 20. 2006. pp. 983-1007.
F. Wang, X. Li, J. Ma, M. Yang. “Experimental investigation of characteristic frequency in ustteady hydraulic behavior of a large hydraulic turbine”. Journal of Hydrodynamics. Vol. 21. 2009. pp. 12-19.
Y. A. Cengel, M. A. Boles. “Thermodynamics: An engineering Approach”. 4ª ed. Ed. McGraw-Hill. New York. 2001. pp. 2.43-2.44.
F. Casanova, “Failure analysis of the draft tube connecting bolts of a Francis-type hydroelectric power plant”. Engineering Failure Analysis. Vol. 16. 2009. pp. 2202-2208.
How to Cite
Copyright (c) 2018 Revista Facultad de Ingeniería
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Revista Facultad de Ingeniería, Universidad de Antioquia is licensed under the Creative Commons Attribution BY-NC-SA 4.0 license. The material published in the journal can be distributed, copied and exhibited by third parties if the respective credits are given to the journal. No commercial benefit can be obtained and derivative works must be under the same license terms as the original work.