Advanced Vibration Diagnostics Reveal the True Cause of Turbo-Generator Blade Failure
This OROS application note details a root cause investigation into a blade failure on a 15 MW turbo-generator at BASF. After an overhaul, the machine experienced unexpected blade damage, prompting a comprehensive vibration and rotor dynamic analysis using advanced diagnostic tools.
Tests ruled out speed instability, torsional resonance, and balancing issues. The investigation concluded that excessive steam extraction in the exhaust system caused blade excitation and failure, highlighting the importance of in-depth vibration diagnostics in turbomachinery.
Article Highlights:
- Root cause investigation of a blade failure on a 15 MW turbo-generator at BASF.
- Advanced vibration diagnostics performed using OROS analyzer and ORBIGate software.
- Speed stability, torsional vibration, torque, and shaft centerline behavior were all analyzed.
- No issues found with speed regulator, torsional resonance, or balancing.
- Slow-roll vibration traced to turning gear eccentricity — not a fault condition.
- Root cause identified as excessive steam extraction in the exhaust system, leading to blade excitation and damage.
- Highlights the value of detailed rotor dynamic and vibration analysis in preventing unplanned downtime.
Key Takeaway:
Comprehensive vibration and rotor dynamic analysis is essential for accurately diagnosing turbomachinery failures — in this case at BASF, advanced diagnostics ruled out mechanical and control issues and revealed that excessive steam extraction caused the blade damage, demonstrating the importance of detailed data-driven investigation to prevent unnecessary downtime and misdiagnosis.