Analysis and Treatment of Vibration Fault of a 1 050 MW Steam Turbine Generating Unit

Abstract

During the capital construction commissioning of unit No.1 of a 2×1 050 MW coal-fired power plant， vibration of bearings No.5 and No.6 exceeded the set standard and become rather unstable， holding up the project. Through vibration test and analysis， it is found that: 1）there are dynamic and static collision and thermal imbalance in low-pressure cylinder B， resulting in excessive vibration of bearing No.5； 2）the bottom load distribution on the generator stator is poor， and the bearing No.6 has a weak dynamic stiffness， resulting in excessive and unstable vibration. Through comprehensive treatment measures， such as the dynamic and static clearance adjustment based on the cylinder impact test， the stator gasket adjustment of the bottom load test of the generator stator， and field dynamic shafting balancing， the vibration fault is controlled， and the operational stability of the unit is improved. Part of the treatment experience has been successfully applied to the vibration prevention of unit.2， which indicates that this case can be employed as a good engineering reference.

Keywords

• steam turbine generating unit
• load distribution
• collision
• cylinder impact
• dynamic balance