Lifetime Deterioration of Turbine Components During Start-Ups

Market requirements of power supply reliability force both manufacturers and operators of power machinery to take adequate care of a unit’s equipment. A unit’s reliability strongly depends on how it is operated. The operating conditions of this kind of equipment are very complex, mainly in terms of unsteady thermal and mechanical loading. In this paper the authors try to show the influence of different ways of operation on the turbine component strength state, lifetime and some safety aspects. The analyses are carried out by means of the FEM using the real measurements. Real parameter gradients within a single initial thermal state significantly differ from the manufacturer’s instructions. This of course results in the size of the components’ stress level and, consequently, in fatigue. In this paper the authors point out the problem mentioned above and show to what extent the speed of start-up influences the stress state and durability of the steam turbine components.