Pilot Study: Test Rig for Self-lubricating Kaplan Runner Bearings

Abstract: Hydropower has a relatively small impact on the climate and contributes to almost half of Sweden’s electricity production. Vattenfall own and operate roughly 125 large scale hydro power units of which about half utilizes a Kaplan turbine. During the last 15 years Vattenfall have been using self-lubricating bearings in their Kaplan turbine runners to reduce the amount of oil in the unit and reduce the risk of oil spill into the rivers. By improving the properties of self-lubricating bearings in terms of friction and wear resistance the service life of overall runner can be increased. Vattenfall would like have full scale tests with representative conditions performed with these bearings. Hence, to test the self-lubricating bearings under more relevant conditions a full-scale test rig needs to be designed. In this thesis, one of the Kaplan turbine units of Vattenfall has been analyzed in order to study the arrangement of the blade shaft and bearings for the design of the test rig. The main objective of this thesis is to perform a pilot study of full scale tests of self-lubricating Kaplan bearings, study what work have done and if needed, develop a concept on how to design a full scale test rig with the ability to recreate the conditions in a real Kaplan runner. The Solid Edge software was used for the creation of 3D models of different components for the test rig. The force structure in the turbine has been implemented on the hub model of Kaplan turbine. One of the Vattenfall unit of Kaplan turbine runner has been analyzed using Ansys 19.1, a simulation software. Structural analysis has been carried out to understand the effect of various forces on the turbine. Further, a full scale test rig has been designed for the self-lubricating bearing in the Kaplan turbine blade.