V84.2 Gas Turbine Coating Additions for Durability Improvement
The V84.2 gas turbine possesses a turbine inlet temperature (TIT) in the range of 1060 to 1080 °C, depending on the specific design version. It therefore relies on various thermal barrier coating (TBC) systems in the combustion and turbine “hot” section to ensure adequate durability of components in these areas. However, the OEM design or “bill of material” does not include TBC on many components, or areas of components, which clearly would benefit by the addition of TBC systems due to oxidation and/or thermal erosion in service. In addition, due to dynamic vibration, several of the combustion system component interfaces suffer significant fretting wear, which could benefit from a “wear” or “hardface” coating system to maintain clearances and component wall thickness.
Several years ago, Eta Technologies LLC (Eta Tech) introduced TBC and wear coating systems in the V84.2 gas turbine which have proven to increase durability, extend component life and thus lower unit life cycle costs. Coating additions implemented by Eta Tech include full gaspath TBC of inner casings, TBC of combustor dome plates, burner insert rings and mixing chambers. Wear coatings have been added to dome plates, burner insert rings, inner casing inlets, mixing chamber transition rings, K-rings and inner casing inlet bowl ring fingers. Inspection after removal from numerous major outage intervals have clearly shown the benefit of these Eta Tech engineered coating additions.
For V84.2 end users, Eta Tech continues to provide modifications and upgrades to maximize durability and minimize maintenance costs!