| Due to the interplay between rotors, journal bearings, oil films and machine foundations, turbo-sets must be viewed as extremely complex machines. The number of spring-mass systems and influences of dynamic forces excite these machines into an intricate pattern of vibrations. These forces are also influenced by the operational mode. Subsequently, to analyse this pattern it is important to clearly separate the possible operational modes. A distinction is made between various operational modes. These are: - Zero-speed
- Barring operation
- Run-up from zero-speed to nominal speed or speed range
- Normal operation at nominal speed or in nominal speed range
- Coast-down to zero speed
Within these modes, the focus is on normal behaviour. One objective is to accurately describe the normal behaviour and highlight any significant deviations. Comprehensive knowledge of the machines and long-term operational behaviour is necessary for a detailed and spot-on diagnosis of the vibration data of turbo-sets. | | |
