Design of link assembly for runner blade actuation in a Kaplan turbine
2019 (English) Independent thesis Advanced level (professional degree), 20 credits / 30 HE credits
Student thesis Alternative title
Konstruktion av länkpaket som möjliggör manövrering av skovelblad i kaplanturbin (Swedish)
Abstract [en]
The reliability and robust power generation of the hydro power plants must be sustained. Therefore, the components must handle the stresses that arise during operation to ensure the expected lifetime of the power plant. The Kaplan turbine utilize its blades on the runner to optimize the efficiency depending on the current load and to ensure this function, the internal runner components must not fail.The blade adjustment is made possible by a hydraulic servomotor actuating a link package that rotate a lever like a slider-crank mechanism. This lever is attached to the blades and the blades will thus rotate if the servo moves up and down. The company Andritz Hydro AB have seen problems with the link package design and needed to investigate if it could be improved. The main problems involve failure of pin locks and rotating sleeves. This report go through the concept development of a new link package design, with methods described by Ulrich and Eppinger. In total 35 new concepts were developed with one being further investigated and designed to fit in the seven bladed runners in two power plants located in midSweden. The designs were evaluated against the current link packages in the aspects of fitment, assembly, mechanical strength and what modifications were needed to components other than the link packages. No strength evaluation was made for one of the turbines and no fatigue calculations were done for either one.The new design showed improvements in manufacturing costs and assembly time due to a new lockplate design and the need of sleeves is eliminated. Fitment of the new design link packages would require minor modifications to existing components in the turbines. One of the investigated turbines have a Finnish design, which showed that there won’t be enough clearance to fit the new design in that specific runner. This is due to the crosshead support being integrated in the hub, instead of being a separate component. The analysis made showed that the new design were in some areas better than the old reference design regarding strength, but for the most aspects they were equal.The new link package design will theoretically be an improvement compared to the old link design.
Place, publisher, year, edition, pages 2019. , p. 53
Keywords [en]
Kaplan, Kaplan turbine, link assembly, link package, LTU
National Category
Mechanical Engineering
Identifiers URN: urn:nbn:se:ltu:diva-74467 OAI: oai:DiVA.org:ltu-74467 DiVA, id: diva2:1324100
External cooperation
Andritz Hydro AB
Subject / course Student thesis, at least 30 credits
Educational program Mechanical Engineering, master's level
Supervisors
Examiners
2019-06-132019-06-132019-06-13 Bibliographically approved