JOURNAL BROWSE
Search
Advanced SearchSearch Tips
Simulation model for Francis and Reversible Pump Turbines
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
Simulation model for Francis and Reversible Pump Turbines
Nielsen, Torbjorn K.;
  PDF(new window)
 Abstract
When simulating the dynamic behaviour of a hydro power plant, it is essential to have a good representation of the turbine behaviour. The pressure transients in the system occurs because the flow changes, which the turbine defines. The flow through the turbine is a function of the pressure, the speed of rotation and the wicket gate opening and is, most often described in a performance diagram or Hill diagram. In the Hill diagram, the efficiency is drawn like contour lines, hence the name. A turbines Hill diagram is obtained by performance tests on scaled model in a laboratory. However, system dynamic simulations have to be performed in the early stage of a project, before the turbine manufacturer has been chosen and the Hill diagram is known. Therefore one have to rely on diagrams for a turbine with similar speed number. The Hill diagram is drawn through measured points, so for using the diagram in a simulation program, one have to iterate in the diagram based on curve fitting of the measured points. This paper describes an alternative method. By means of the Euler turbine equation, it is possible to set up two differential equations which represents the turbine performance with good enough accuracy for the dynamic simulations. The only input is the turbine's main geometry, the runner blade in- and outlet angle and the guide vane angle at best efficiency point of operation (BEP). In the paper, simulated turbine characteristics for a high head Francis turbine, and for a reversible pump turbine are compared with laboratory measured characteristics.
 Keywords
Hydropower;Turbines;Characteristics;Simulation;
 Language
English
 Cited by
 References
1.
Dorfler P.K., Engineer A.J., Pendse R.N:, Huvet P., Brahme M.V.. Stable operation acvhieved on a single -stage reversible pump-turbine showing instability at no-load. Proceeding of the 19th Symposium on Hydraulic Machinery and Systems. 1998. Singapore.

2.
Nielsen T.K., Svarstad M.F. Unstable behaviour of RPT when testing turbine characteristics in the laboratory. 27th IAHR Symposium on Hydraulic Machinery and Systems, 2014, Montreal.

3.
Martin, C.S. Stability of pump-turbines during transient operations. 5th International conference on pressure surges, 1986, Hannover, Germany.

4.
Nielsen T.K, Olimstad G., Dynamic Behavior of Reversible Pump-Turbines in Turbine Mode of Operation, in International Symposium on Transport Phenomena and Dynamics of Rotating Machine, 2010, Honolulu.

5.
Olimstad G., Borresen B., Nielsen T.K., Geometry Impact on Pump-Turbine Characteristics, in 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machine. 2012 Honolulu.

6.
Staubli T., Senn F., Sallaberger M., Instability of pump-turbines during start -up in the turbine mode. Hydro 2008, Ljubljana.

7.
Olimstad G., Borresen B., Nielsen T.K., A Two Dimensional Model for Pump-Turbine Instability Investigation, in 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machine, 2011, Honolulu.

8.
Olimstad,G., Nielsen, T.K., Borresen, B. Sability Limits of Reversible Pump Turbines in Turbine Mode of Operation and Measutrements of Unstable Chracteristics. Journal of Fluids Engineering, 2012, Vol. 134

9.
Olimstad,G., Nielsen, T.K., Borresen, B. Dependency on Runner Geometry for Reversible-Pump Turbine Characteristics in Turbine Mode of Operation. Journal of Fluids Engineering, 2012, Vol 134