Investigation of vibrations of shafting turbine unit T-250/300-240 at drawdown of supports and instantaneous imbalance shafting

• Datum: 2015
• 1. Verfasser: Гармаш, Н. Г.
• Format: Artikel
• Sprache: Ukrainian
• Veröffentlicht: Інститут енергетичних машин і систем ім. А. М. Підгорного Національної академії наук України 2015
• Schlagworte: rotor; shafting; turbine; defect; vibration characteristics; УДК 539.3; 539.4
• Online Zugang: https://journals.uran.ua/jme/article/view/40254
• Назва журналу: Energy Technologies & Resource Saving

The methodology and software that enables based on the finite element method with the direct integration of the motion equations by Newmark’s method solve problems forced flexural, longitudinal, torsional vibrations and transients shafting on complex elastic-damper supports, are developed. Software allows to determine the vibration characteristics of initial defects and defects that have arisen during operation of turbine shafting. The finite element calculation model of rod shafting turbine unit T-250 / 300-240 is used. Discs stages with blades, couplings, flanges or balancing weights are modeled by concentrated masses and moments of inertia. At the junction of neighboring rotors, the stiffness coupling elements are taken into account, as well as imperfections connection - radial clearance (crankshaft) or a kink of axis plots. Model identification is carried out on the basis of the experimental values of the vibration characteristics obtained by the vibration-diagnostics system. Numerical simulation of the vibrations of the turbine shaft T-250 / 300-240 is performed in such cases imperfections of connection flanges rotors as misalignment of rotor axis (crankshaft), kink of shafting axis, drawdown of supports and instantaneous imbalance shafting. Taking into account the defects leads to a change in amplitude, phase and frequency vibrations, as well as the trajectories of individual points shafting. The results obtained allow us to estimate the influence of the most widespread defects on the vibration characteristics of shafting. These symptoms of defects extend the capabilities of an expert system to assess their availability and development, which is part of the automated system of turbine vibration diagnostics.