The first Session was dedicated to end users only. The end user day featured a number of fascinating case studies covering noteworthy events and lessons learned. As if that wasn't enough, attendees also got to participate in an engaging Q&A session with fellow users. This session covered the burning questions that had been gathered via the pre-conference questionnaire and sparked some lively discussions. All in all, it was an exciting and informative experience for everyone involved!

Some of the key lessons discussed:

• RLE and an overhauled exchange rotor
  • Rotor life assessment should be done prior 144kFFH. There are options how to manage rotor life extension. Original rotor can be analyzed at the workshop and if needed overhauled for possible extra life. This procedure requires long downtime that is not always possible for plant operation. Another solutions is a refurbished or new replacement rotor that can be prepared prior scheduled Major Overhaul of the unit and installed during the MO to get the Unit back online soonest.
    In 2022, during a scheduled Major Inspection, the user's rotor was reaching 169,000 FFH, and a rotor exchange was performed. The original rotor was inspected and overhauled, and a replacement rotor was selected to reduce unit downtime. Additionally, the remaining life after RLE might only be one MI cycle, but with a replacement rotor, a longer life extension could be reached. The refurbished rotor was fully inspected and overhauled before delivery to the site.
• Liquid fuel operating experience
  • The user showed experience in operating gas fuel DLN 2.6+ with backup Light Fuel Oil. The unit was originally designed for dual fuel application where gas is the primary fuel and LFO is the backup fuel. Due to the increase in gas prices globally, the unit had to be operated temporarily with LFO. The changeover from gas to LFO and back was successful. Combustion using LFO and water injection for NOx control worked as planned without any problems. Some minor improvements are needed for the auxiliary systems, such as improving the reliability of the flame detection and combustion dynamic monitoring system.
• Compressor clashing
  • Compressor clashing during startup sequence was presented. Different phenomenons that can cause compressor clashing was discussed together with possible root cause analysis. As the fleet ages, special attention should be paid on the condition of stator vanes and carrier rings.
• Load gear barreling
  • 6FA load gear is one of the largest gears manufactured. Gear operates under different operating parameters like temperatures, speeds, oil quality and flow, load, shaftline alignment that all can affect gear lifetime and condition of wheels. Proper inspections are important to determine and document the condition of the gear:
    • Evaluation of actual contact pattern with red dye and indications of micropitting.
    • No load tooth contact to evaluate shift of contact area.
    • Backlash measurement.

Are you an owner or operator of a F6FA gas turbine? If you're not already a part of the GTUsers Users Group, it's time to join. Head over to GTUsers.com and register now to get all the latest news, insights, and discussions surrounding this unit. Join the community and take your F6FA expertise to the next level!

OEM GE Gas Power Session
GE delivered comprehensive and technical lectures that addressed the questions raised by the end users. They provided updates on the latest technical developments, fleet status, and TILs. Additionally, GE arranged a visit to their workshop that included break out sessions and a tour of the manufacturing and repair shop floor.

Conference GE day included the following main topic areas:

• Decarbonization and fuel flexibility for the 6FA DLN2.6, 2.6+, and new DLN EVO combustion systems. They provided insights into the limits of hydrogen blending with natural gas without requiring significant changes in plant hardware, and when modifications to combustion and/or auxiliary systems are needed. Additionally, GE presented readiness and challenges related to operating with biofuels and ammonia.
• Control system upgrades and particularly cybersecurity
• The auxiliary session covered crucial but often overlooked systems, such as the Static Frequency Converter (SFC). When the SFC reaches the end of its lifespan, it can be challenging to find spare parts and technical support. The upgrade process for the SFC was extensively reviewed, including the necessary replacement work and commissioning time.
• Opflex opportunities. Flexibility is a must! Opflex controls offer a range of solutions for a variety of challenges, both market-driven and operational. Whether it's the need for a turndown extension, faster startup, management of transient situations, or increased availability through advanced exhaust spread monitoring, Opflex controls are designed to address these challenges and more.
• TILs related to gas turbine and accessories were discussed with the audience in order to provide a thorough understanding of the reasons behind each TIL and its recommended actions.
• RLE scopes and critical rotor components for 6FA.01and 6FA.03 depending on operational profile (starts based or hourly based maintenance).

And, last but not least, the Q&A session was a crucial part of the event, where end-users had the opportunity to ask detailed questions. GTUsers and the SteerCo collected questions from end-users in advance, ensuring that all queries were answered thoroughly by GE experts, leading to lively discussions and a deeper understanding of the topics presented.

MJB International

MJBI was pleased to participate in this year’s F6FA Users Conference in Budapest on 18th April 2023 and would like to thank all those who attended the event.

MJBI is a highly experienced independent gas turbine service provider dedicated to providing our customers with a wide range of technical services and innovative solutions that add value to their operations.

Eric Osterberg (Business Development Manager) used the opportunity to highlight the wide range of aftermarket maintenance, repair and overhaul solutions MJBI continues to develop for the advanced technology 6FA gas turbine fleet.  MJBI works closely with end users under LTSA or on a transactional basis and fully understands what it takes to successfully operate and maintain their critical rotating equipment packages. Using recent examples of 6FA maintenance, repair, overhaul and supply scopes that MJBI has performed, Eric was able to demonstrate to the Users Group MJB’s significant 6FA product and service offering.  

More information about MJBI products, services and capabilities can be found at mjbi.com

MECHANICAL DYNAMICS & ANALYSIS

MD&A's presentation covered the repair and new manufacturing of DLN2.0 and DLN2.6 fuel nozzle assemblies with end covers.

Understanding the crucial role of the fuel nozzles is important to avoid operational problems like:

• Temperature spreads increasing
• Flashbacks and lean blowouts
• Inability to tune the engine
• Emissions not stable at start-up and full-load conditions
• Unit trip at start-up due to emissions
• Machine being de-rated.

MD&A showcased several case studies where a combination of thorough fuel nozzle refurbishment and MDA's specific upgrades resulted in significantly improved combustion reliability, low emissions, and extended component lifetimes. These upgrades were also shown to significantly reduce owning and operating costs by delivering "same-as-new" quality at a fraction of the cost of purchasing a new part. Just to mention some of the refurbishment tasks:

• Outer center nozzle life extension and remanufactured outer gas nozzles
• Insert repairs
• Replacement of wear components
• Proper flow testing and matching of nozzles.

MD&A also showed their capabilities to repair AGP components and thereby extend the life of critical assets.

GTC

GTC Control Solutions a Division of AP4 Group always have interactive case studies presented and this time a topic "Being an Owner’s Engineer during controls upgrade project" was discussed.
Control upgrades require proper owner's engineering to monitor that the supply fulfills customer expectations technically and schedule is kept.
Main tasks are:

1. Identify all the deliverables and the promised dates
2. Review design documentation not only what is included but also what is MISSING
3. Pre-commissioning: Loop checks, out of scope works, critical signals
4. Commissioning: Planning like loading, cooldown, waterwash, fuel change over
5. Testing: Redundancy, overspeed
6. Keep a proper punch list
7. Final documentation

GTC has been involved as an owner's engineer in a number of control system upgrades, including MarkV to MarkVIe and EX2100 to EX2100e upgrades. In this role, GTC ensures that the scope of work is complete and that no important features are missed during the upgrade process. This helps to ensure that the upgrade is successful in improving the performance and reliability of the gas turbine control system.

Dekomte

Dekomte is a leading manufacturer of fabric and metallic expansion joints and bellows, engineered to compensate for the changes in length caused by shifting temperatures in ductwork. Axial, lateral and angular movements are compensated for.

Dekomte expansion joints are available in any geometric shape (round, square, oval, multi-sided) and in any size.

Dekomte's approach to expansion joint selection and maintenance is based on being a solution provider for their customers. They explained the technologies, selection criteria, and importance of proper maintenance for expansion joints, including:

•  Providing expansion joints for a variety of gas turbine models as an OEM supplier.
•  Offering custom designs with their special DEKOMTE '3WA' solutions for high cycling applications, ensuring reliable and long-lasting performance.

Dekomte presented a number of compelling case studies, including one involving the transition of a 6FA gas turbine. In this project, Dekomte supplied a complete new expansion joint between the GT and HRSG, complete with internal insulation. The installation process was carried out with impressive efficiency, resulting in minimal outage duration and maximum cost savings for the customer.

At the 6FA user conference, there were also several other important third-party service providers present, including:

Minimax

National Electric Coil

Trinity Turbine Technology

Emerson Controls

Turbine Services Ltd.