The Strength And Rigidity Analysis Of Large Capacity Francis Turbine Parts-Spiral Case And Stay Ring

The structural size of the hydro-generating unit becomes larger and larger; The strength and rigidity of the parts becomes important to the operation of the machine.Using the large FEA software-IDEAS, this thesis mainly researches on the analysis of Spiral case stay ring in YunNanJingHong hydro-generating unit, which is the ongoing study in institute of HarBin generator. The main conclusions are shown in the following:1. The traditional FEA of spiral case and stay ring under the condition of without concerning concrete. Finally the stress and displacement of the spiral case and stay ring without concerning the concrete are calculated.2. Introduction of variational analysis technology. This includes the basal theories of variational analysis, the virtues of variational analysis, the use of variational analysis and the comporation between traditional FEA and variational analysis. Finally the thesis illustrates the use of variational analysis with a actual case.3. The variational analysis of spiral case and stay ring's strength. Not only the thickness parameters of spiral case and stay ring but also the structural parameters are used for variational analysis. Finally the parameters which influence the strength of the structure highly are enquired.4. The strength and rigidity analysis of the spiral case and stay ring concerning the concrete. This chapter presents the two usual conditions: spring layer between spiral case and stay ring and concrete, hollow gap between spiral case and stay ring and concrete. These two conditions are both calculated. Moreover how the strength of spiral case and stay ring changes when the physical parameter changes is also calculated.