Retrofit And Design Of Increasing Capacity And Cavitation Resistance Of Kaplan Turbine Runner Based On CFD

There is a large part of Kaplan turbine built before80’s in20centuries in our country,their running stability is poor、cavitation damage is very serious、comprehensive performanceis very low, with the development of modern turbine technology and widely application ofCFD technology,it needs pay more attention to the technological innovation of Kaplan turbine,the improvement of the hydraulic performance, the reduction or improvement of the axialflow turbine’s cavitation,these problems need to be addressed imminently.In this paper, theaxial flow turbine’s transformation and design about capacity and corrosion is studied byCFD, which has great significance to improve the overall performance of the whole unit andthe running stability.Based on this,the specific objects of study is the axial flow turbine’s transformation aboutcapacity and corrosion in the Dujiangyan Shuangbo power station.there is a feasibility studyabout the axial flow turbine’s transformation and design about capacity and corrosion,it takesadvantage of the power station existing hydraulic conditions and runner blade size totransform the original Kaplan unit’s capacity and corrosion. By analyzing the hydraulicparameters,the design of the transformation can not change the original unit over the flowchannel and the geometry,on the basis of the traditional axial flow turbine lift method,considering the impact of the flow between flange clearance of the impeller and the flowboundary layer. The hydraulic design use an improved lifting model,in creasing capacity from5000Kw to6000Kw, gaining two schemes of the runner blade drawing (including airfoilprofile, the runner blade axial plane projection and the projection plane), And takingadvantage of CFD technology to make numerical simulation and analysis about the internalflow field of the hydraulic model, the wheel’s internal flow of the new design is considered tobe relatively good by model calculation and analysis,fully able to meet the purpose of thecapacity increase, as well as making the calculation and analysis of the internal pressure of thewheel, can play a good role of cavitation corrosion skirt from the back of the skirt structure ofthe original unit to face skirt structure effect. These technical solutions and measures have allbeen used in the transformation of the power station, it has good effect.The scene running situation after the unit transformation shows that the transformedunit’s operation efficiency is improved,its overall performance has been greatly improved,theeconomic benefits of the power stations is created significantly,it also shows that thetransformation of the runner blades is valid by CFD technology and the improved liftingmodel.