Dissertation > Excellent graduate degree dissertation topics show

Safety Analysis on Torsional Vibration of Large Steam Turbo-generator Shafts

Author: PangLe
Tutor: GuZuoJiong
School: North China Electric Power University (Beijing)
Course: Thermal Power Engineering
Keywords: steam turbine units torsional fatigue finite element method safety analysis rain-flow counting method
CLC: TM311
Type: Master's thesis
Year: 2011
Downloads: 66
Quote: 0
Read: Download Dissertation

Abstract


Today, electric power industry is developing towards more large-scale unit capacity and more complicate grid, leading to increasingly prominent problems of the shafts torsional vibration,which is big threat to the security of the units and grid. This paper gives in detail the current research progress of safety analysis on torsional vibration of turbo-Generetor shafts at domestic and international, describs the problems of existing theories, and then does some further research about it and also puts forward corresponding solutions. The method of shafts modeling is discused, advantages and disadvantages of methods to calculate shaft inherent characteristics is compared and analysed, and the superiority of verified riccati-transfer-matrix method is verified, using the finite element method. The calculation principles of shafts response is analyzed, and the analytical algorithm of shafts response under two-phase short circuit is deduced. Thoroughly analysis is given to reverse fatigue S-N curve and its influence factors, such as torsional mean stress and high cycle fatigue. The corresponding analytical correction formula is obtained and its accuracy is verified by finite element method. This paper also presents an improved model of real-time rain-flow counting, which eliminates the defects of the original model which easily produces leakage point in the second stage. Combining the malfunction response characteristics, the threshold of the fatigue accumulating damage is analyzed specially and studied quantitatively under different load spectrum, which provides theory basis for torsional vibration monitoring and warning. The method of checking torsional intensity of axis is analyzed, the correlation of intensity checking and fatigue damage is discussed, and the changes of torsional fatigue limit is obtained under fatigue damage. The paper probes the safety strategy analysis of torsional vibration at home and abroad, gets fatigue life loss range of shafts withstanding an impact under all kinds of faults, and put forward the method of computing element’s value at risk, which lay a foundation for torsional vibration safety analysis. The safety of shafts is analyzed by combining with low-pressure rotor wear fault of one power plant and two-phase short-circuit faults of the other power plant, which verifies the feasibility and accuracy of the corresponding theory. The study of this paper will have a positive significance on real-time life assessment and safety analysis of torsional vibration in power shafts.

Related Dissertations

  1. Research on the Structure and Characteristics of Permanent Magnetic Coupling,TH139
  2. Simulation Analysis on Temperature Stress of RCC Arch Dam and Its Construction Joints Design Research,TV642.2
  3. Stability Analysis of Roller Compacted Concrete Gravity Dam Based on Time-history Method,TV642.2
  4. Research on Intelligent Aerial Bomb for Forest Fire Fighting,S762
  5. Study of Gray Neural Network Model of Enterprise’s Safety Devotion,X913.4
  6. The Band Structure in 2D Resonant Phononic Crystal,O735
  7. Research on Security-check Information System Based on Multi-information Fusion,V328.3
  8. Research on Sensing with High Birefringent Photonic Crystal Fiber,TP212
  9. Numerical and Experimental Studies for Multi-Cracks of Asphalt Pavement with Semi-Rigid Basement Asphalt,U416.217
  10. Study on the Influence of Various Defects on the Characteristics of Infrared Photonic Crystal Fiber,TN253
  11. Applications of Vector Finite Element Method to Simulate Logging While Drilling Resistivity Tools,P631.83
  12. Uniform deformation laminate interlaminar stresses Numerical simulation and high-temperature creep behavior of 40Cr steel,TB33
  13. Scrap copper smelting furnace temperature measurement method,TF811
  14. Space hyperspectral imager Compensation focusing optical system of pre-,TH743
  15. Study of Composite Drive Shaft for an Automobile,U465.6
  16. Vehicle-mounted snubbing workover rig derrick Design and analysis,TE935
  17. Particle reinforced copper matrix composites mechanical behavior of finite element analysis,TB331
  18. Finite element analysis of gear transmission machine and Kinetics,TH132.41
  19. Large opening pressure vessel structural finite element analysis and strength design,TH49
  20. Composite cage rotor induction motor starting performance of the design and research,TM343
  21. More rarely slot reactance permanent magnet synchronous motor parameter calculation and research,TM341

CLC: > Industrial Technology > Electrotechnical > Motor > Generators, large the generator group ( Zonglun,) > Turbine Generator
© 2012 www.DissertationTopic.Net  Mobile