Diagnosis and Treatment of the Shaft Vibration Problem for an Ultra Super-critical 700MW Unit

Abstract

In this article, there existed a second order unbalance on LP1 shaft of a Super-critical 700MW unit. It can be derived from the mathematical model of flexible and symmetrical shaft vibration characteristics that there are two specific balancing methods, symmetrical for handling odd orders and symmetrical reverse for even orders. The symmetrical reverse balancing method is proved to be effective to solve the second order vibration problems.