Vibration Characteristics and Damage of Turbine Generator Shaft Rubbing

2014 ◽  
Vol 697 ◽  
pp. 210-213 ◽  
Author(s):  
Rong Pei Zhang
Keyword(s):  
Temperature Change ◽  
Vibration Characteristics ◽  
Lubricating Oil ◽  
Turbine Generator ◽  
Rotor Shaft ◽  
Turbo Generator ◽  
Deep Groove ◽  
No Elimination ◽  
Generator Unit

An abnormal journal vibration occurred when a 660MW turbo generator unit was in daily operation. It was identified that rubbing vibration had taken place based on the behavior of the journal vibration and the temperature change of lubricating oil. The rubbing was located inside the bearing box between the HIP rotor and the LP rotor. However, no elimination measures had been taken in time because the damage caused by rubbing was underestimated. Few months later a full inspection revealed that the LP rotor shaft had been worn out with a 70mm wide and 28mm deep groove, which greatly weakened the strength of the LP rotor. The analysis presented here may help in diagnosing and understanding rubbing-vibration-related problems in similar situations.

Characteristic Study of Torsional Vibration on a Full Size Turbine-Generator Unit

1991 ◽  
Author(s):  
Huang Xiuzhu ◽  
Zhang Xueyan ◽  
Sun Daixia ◽  
Gong Qing
Keyword(s):  
Torsional Vibration ◽  
Vibration Characteristics ◽  
Turbine Generator ◽  
Full Size ◽  
Torsional Response ◽  
Shaft System ◽  
Switch Operation ◽  
Shaft Torque ◽  
Generator Unit

Abstract Taking a 200MW turbine-generator unit and its connected transsmision network as a study object, torsional vibration characteristics of the shaft system caused by faulty synchronization, different disturbances in the network and switch operation were analysed and calculated. The effect of intensive excitation and “fast valve closing” on the torsional response is also discussed. It is concluded that large mechanical torque of shaft system would be encountered if there is a 3-phase fault in the network, and the shaft torque would be reduced to a certain extent by giving the “fast valve closing” if the network experience a fault.

Application of Improved Genetic Algorithm in Maintenance Decision for Turbine-Generator Unit

2010 ◽  
Vol 44-47 ◽  
pp. 2940-2944
Author(s):  
Qing He ◽  
Jian Ding Zhang
Keyword(s):  
Genetic Algorithm ◽  
Heuristic Algorithms ◽  
Maintenance Scheduling ◽  
Improved Genetic Algorithm ◽  
Turbine Generator ◽  
Executive Process ◽  
Generator Unit ◽  
Maintenance Decision ◽  
Constrained Conditions ◽  
Operating Unit

The complicated function relations are more prone to appear in the maintenance scheduling of steam-turbine generator unit. Many constrained conditions are often attendant with these function relations. In these situations, the traditional method often can not obtain the exact value. The genetic algorithm (GA), a kind of the heuristic algorithms, does not need the function own good analytic properties. In addition, as the operating unit of GA is the group, so it applies to the parallel computing process. In GA executive process, the offspring continually inherit the genes from the parents, so it is more prone to be involved in the local convergence. An improved genetic algorithm is proposed and used in the model of maintenance decision of turbine-generator unit under. The goal of the model is to seek to the rational maintenance scheduling of the generator unit, so as to minimize the sum of the maintenance expense, the loss of the profit on the generated energy, and the loss of the penalty. It is proved by the example that IGA is highly efficient.

A New Model for the Relationship Between Vibration Characteristics Caused by the Time-Varying Contact Stiffness of a Deep Groove Ball Bearing and Defect Sizes

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Jing Liu ◽  
Yimin Shao ◽  
W. D. Zhu
Keyword(s):  
Surface Defect ◽  
Ball Bearing ◽  
Contact Stiffness ◽  
Vibration Characteristics ◽  
Time Varying ◽  
Defect Depth ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Length Width ◽  
The Relationship

Vibration characteristics of a deep groove ball bearing caused by a localized surface defect are greatly affected by defect sizes, such as the length, width, and depth. However, effects of the defect depth, the time-varying contact stiffness between the ball and defect, and the relationship between the time-varying contact stiffness and defect sizes have not been considered in previous defect models. In this work, a new defect model considering a new force–deflection relationship is presented to replace the Hertzian force–deflection relationship to describe the ball-line contact between the ball and defect edge. Both the time-varying displacement impulse and time-varying contact stiffness are considered. The relationship between the time-varying contact stiffness and defect sizes is obtained. Effects of defect sizes on the vibrations of the deep groove ball bearing, especially the defect depth that cannot be described by previous defect models, are investigated. The simulation results are compared with those from the previous defect models. The results show that the model developed can predict a more realistic impulse caused by a localized surface defect for dynamic simulation of the deep groove ball bearing. An experimental investigation is also presented to validate the proposed model.

Sign in / Sign up

Export Citation Format

Share Document