Model turbine design and performance improvement analysis of Kesikköprü Hydroelectric Power Plant

In this study, design of a Francis turbine is made based on head and discharge values of the turbines which are currently working in Kesikköprü Hydropower Plant. Computational flow domains of this Francis turbine's components are generated on ANSYS v15 separately. These flow domains are assembled and they constitute the whole Francis turbine's computational model. This model is subjected to CFD analyses for different guide vane angles to determine the effect of guide vanes on turbine performance and efficiency. CFD analyses are carried out on ANSYS CFX. As a result, efficiency values, pressure and velocity distributions are obtained for five different guide vane angles. An efficiency curve is generated based on these values. According to this efficiency curve, 22-degree guide vane position corresponds to the best efficiency point with a 94% efficiency. Thus, 22-degree guide vane angle is decided as the optimum guide vane position for final design. Besides, cavitation analysis is carried out for this final design. According to the results of this analysis, it is obtained that the turbine is cavitation-free. In addition to this, when absolute pressure and gage pressure values are examined from the pressure distribution contours, it is obvious that there's no cavitation in turbine runner. The turbines in Kesikköprü Hydropower Plant are working with the mean efficiency value 89%. As 94% efficiency value is obtained from CFD analyses, there would be an additional efficiency increment about 5% if the rehabilitation process will come true.