Finding the causes of a penstock overload
Root Cause Module algorithms apply expert rules to detect plant operation process errors and equipment malfunctions
The trend analysis of historized data is conducted by RCM to assess the evolution of the risk and impact of warning signs detected. But also, to quantify corrective actions effectiveness after their implementation.
A synthesis of the safety diagnosis is then issued to help Operators to ensure optimal security, this security diagnosis includes the following recommendations :
- Condition-based safety maintenance: initiate a test to validate new settings for inlet stroke valves, or for speed governor tuning.
- Operating support: stop-gap measures as for example the rejection of operating ranges for critical machines, lowering of the head, limitation of the full wickets gate opening.
- Questioning the design of certain key components, as for example: modifying the stroke law of closure of inlet valves, the guard valve bypass implementation.
Example of spherical valve self-sustained seal ring oscillations causing penstock hydro-acoustic resonance.
Penstock cyclical pressure caused by a resonance