The fatigue life of a specific inner casing of an ultra-supercritical steam turbine was investigated under a half year in-service conditions. The Ramberg-Osgood model and Manson-Coffin-Basquin strain-life equation were used to describe the stress-strain behavior and calculate the fatigue damage. A temperature comparison was performed to validate the reliability of finite element model. The results showed that fluctuating steam pressure rather than temperature had more significant effect on the variation of stress in the casing. Locations with high stress level were prone to cause larger fatigue damage. Statistical analysis was carried out to reveal that over half fluctuations of steam pressure could cause damage.

This content is only available via PDF.
You do not currently have access to this content.