MW Recovery with Thermal Performance Software

Event Background

Société Tunisienne de l'Electricité et du Gaz (STEG)uses APM Performance Intelligence as part of their performance monitoring strategy. On June 27, 2024, the software indicated that Gas Turbine 5 at Bouchemma Power Station was experiencing a degradation of 4 MW.

“This event is a show case on the added value of GEVernova digital solution APM PI, wich is a facility to maintain our fleet reliable and efficient. This is aligned with STEG road map to deploy advanced technology, using digital solution to monitor STEG’s Assets.”

Recommendations & Actions

Utilizing APM Performance Intelligence, the STEG M&D team could see which section of the gas turbine the losses were coming from (Figure 1). They requested that the operations team check for observations that could be related to any abnormal operation or change in sensor behavior.
GE Vernova
Figure 1: APM Performance Intelligence trend showing increased degradation on June 27, 2024 in Turbine Efficiency and Misc.

“Daily, we, STEG and GE M&D team, are reviewing and analyzing any deviation observed in the performance trend, KPI’s and asset health. We anticipate to do proactive actions to avoid any unplanned unavailability, this is totally in coordination with site team.”

The site team requested to inspect a purge valve, and it was found not to be opening as per the opening purge order. The site performed 20VG3 purge valve maintenance, which restored the machine performance. The initial site recommendation, extended lean leanoperation of the machine, would have caused significant mechanical damage without resolving this issue. Fuel nozzle inspection has been scheduled in the next BI inspection.
There was a similar history in the past on this machine in 2016 which caused damage to SFN1 and SFN2(Figures 2-3).

Customer Impact

4MW recovery was confirmed by APM Performance Intelligence over the course of the next few days(Figure 1).

Fuel nozzle mechanical damage was avoided, and the total financial impact was estimated to be $351,300 USD (~ 1,068,000 TND) and 96 saved hours (Figure 4).
GE Vernova
Figure 2-3: 2016fuel nozzle damage; significant mechanical damage avoided in 2024
GE Vernova
Figure 2-3: 2016fuel nozzle damage; significant mechanical damage avoided in 2024
GE Vernova
Figure 4: Cost benefit analysis