Parametric optimization to reduce erosion in a Francis turbine runner

29th IAHR Symposium on Hydraulic Machinery and Systems

Valencia, E.A.^1 ; Bone, E.G.^1 ; Yánez, J.A.^1 ; Cando, E.H.^1 ; Galván, S.R.^2 ; Hidalgo, V.H.^1

School of Mechanical Engineering, Escuela Politécnica Nacional, Quito

17-01-2759, Ecuador^1

Mechanical Engineering Faculty, Universidad Michoacana de Sán Nicolás de Hidalgo, Morelos

58030, Mexico^2

关键词: Curvature deviations;    Francis turbine runner;    Geographical positions;    Geometrical features;    Hydraulic parameters;    Optimization parameter;    Optimization studies;    Parametric optimization;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/2/022041/pdf
DOI  :  10.1088/1755-1315/240/2/022041

来源: IOP

【 摘 要 】

More than a half of the overall power capacity in Ecuador uniquely depends on hydroelectric power, thanks to its geographical position and large water resources. Most of them use Francis turbines, which present detriment in their lifetime due to the presence of high hardness sediments in the water reservoirs located close to the Andean mountains. In order to mitigate such effect, a structured methodology, which identifies design space variables and defines parameters that governs the phenomenon is developed. The optimization is carried out through genetic algorithms formulated to determine optimal geometrical features and hydraulic parameters based on Euler meanline turbomachinery equation. The objective function for the optimization study at this preliminary stage was erosion factor, whilst the decision variables used were: outlet diameter, acceleration flow, degree of reaction and percentage of curvature deviation from a linear of the blade angle distribution. The results obtained showed that the erosion factor can be reduced by 49 % and that the relative flow velocity at the exit was a key optimization parameter to decrease the runner erosion. This great improvement at preliminary design has been compared with other similar studies, showing a good enough prediction of erosion and the capturing of the phenomena. Furthermore, the important contribution of the present methodology is the development of a simple and versatile tool to define the design space for erosion phenomena and in this way improve the lifetime of the blade turbine runner and hence decreasing maintenance costs.