Finding the causes of a penstock overload
RCM applies expert rules to detect plant operation process errors and equipment malfunctions
Trend analysis on historized data is conducted by RCM to assess 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 include the following recommendations :
- Condition-based safety maintenance: initiate test to validate new settings for inlet stroke valves, speed governor, generator synchronization…
- Operating support : stop gap measures: rejection of operating ranges for critical machines for transient conditions, lowering of the head, limitation of full wickets gate opening.
- Questioning the design of certain key components, for example: modifying the stroke law of closure of inlet valves, guard valve by pass implementation.
Example of spherical valve self-sustained seal ring oscillations causing penstock resonance fluctuations.
Penstock cyclical pressure caused by a resonance