INFLUENCE OF RUNNING CONDITIONS ON RESONANT OSCILLATIONS IN FRESH-AIR VENTILATOR BLADES USED IN THERMAL POWER PLANTS

Abstract

High frequency cyclic load of fresh air supply to ventilator blades in thermo energetic facilities can cause the occurrence of fretting in the pressed overlap of ventilator shaft and socket. These loads can be generated by the resonant oscillations of ventilator blades and thermal residual stress due to welding. To prevent running in resonant conditions, the manufacturer of the ventilator defined a procedure of adjusting blades natural frequency in the process of production, as well as period control during exploitation period. The numerical simulations and the accelerations measured and presented in this paper, enabling analysis of mass changes and rotation rate effects on resonant oscillations occurrence in fresh air ventilator.

Keywords

Dates

  • Submission Date2008-10-20
  • Revision Date2008-11-01
  • Acceptance Date2009-02-11

DOI Reference

10.2298/TSCI0901139T

References

  1. Tasić, M. M., Transient Heat Conduction in Bearing Bedding of the Fresh Air Ventilator, Diploma Project, (in Serbian), Faculty of Mechanical Engineering, University of Belgrade, Belgrade, 2006
  2. Tasić, B. M., Mitrović, R.,Tasić, M. M., Influence of Resonant Vibrations of W33 Fresh-Air Blades on Shaft Bedding Failure, Machine Design, Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia, 2007
  3. Ristivojević, M., et al., Redesign Report of the Fresh Air Ventilator AN 33e6's Bedding (in Serbian), Faculty of Mechanical Engineering, University of Belgrade, Belgrade, 2002
  4. Šijacki - Žerav~ić, V., et al., Research Report of the Failure of Fresh Air Ventilator AN 33e6's Shaft (in Serbian), Faculty of Mechanical Engineering, University of Belgrade, Belgrade, 2000
  5. Frost, N. E., March, K. J., Pook, L. P., Metal Fatigue, Dover Publications Inc., Mineola, N. Y., USA, 1990
  6. Mitrović, R., et al., Design Analysis of the Power Plant Fresh Air Ventilator's Bedding (in Serbian), Proceedings on CD, International, Symposium Power Plants 2004, Vrnja~ka Banja, Serbia and Montenegro, 2004
  7. Ristivojević, M., et al., Research of the Sources of Working Conditions Failure of the Power Plant Fresh Air Ventilator (in Serbian), Proceedings on CD, Energetika 2005, Zlatibor, Serbia, 2005
  8. Mitrović, R., et al., Transient Heat Conduction in Bearing of Primary Stage Air Fan of Thermal Power Plant (in Serbian), International Symposium Power Plant 2006, Vrnja~ka Banja, Serbia, 2006
  9. Ashby, M. F., Material Selection in Mechanical Design, 3rd ed., Butterworth-Heinemann, Burlington, Mass., USA, 2005
Volume 13, Issue 1, Pages139 -146