METHODOLOGICAL APPROACH TO INTEGRITY ASSESSMENT AND SERVICE LIFE OF ROTATING EQUIPMENT AT HYDROPOWER PLANT – TURBINE SHAFT
Miodrag Arsić1, Radovan Karić2, Aleksandar Sedmak2, Meri Burzić2, Brane Vistać1
1)Materials Testing Institute, Bulevar vojvode Mišića 43, Belgrade
2)University of Belgrade, Faculty of Mechanical Engineering, Kraljice Marije 16, Belgrade
3)University of Belgrade, Faculty of Mechanical Engineering, Innovation Centre, Kraljice Marije 16, Belgrade
Horizontal Kaplan turbines, were installed in 10 hydro-electric generating units at “DJERDAP 2”, total power of 28 MW. Taking into account the fact that fatigue started to occur in many components, the research is conducted regarding the influence of loading regime, work condition and type of damage, on the service life of equipment components. Analytical calculation established values of bending stresses acting on the turbine shaft due to fatigue, corrosion, and stress concentration, that are above 25 MPa in flanges exposed to water, and over 40 MPa for flanges exposed to “corrosive water”, which is also protected by epoxy fibres, possibly causing the occurrence of surface cracks on the transition radius between the cylindrical part of the shaft and the flange.
Keywords: turbine shaft, stress concentration, corrosion, fatigue, crack