Abstract
A Performance Enhancement Kit (PEK) is introduced to infuse the latest technology to MS5001PA fleet there-by existing customers benefit from increased output, extended inspection intervals, improved reliability, and operability. The kit includes advanced-technology combustion system with improved design of hot gas path (HGP) components. The components in the KIT are designed for either enhanced output of 6% or for an increased interval between repairs or increased ‘Mean Time Between Maintenance’ (MTBM) from 24khrs to 35khrs. Initially PEK was introduced as part of MS5001PA in 2016 for standard combustor. Present study shows its application to Dry Low NOx (DLN) combustion system without affecting Maintenance Interval (MI). PEK DLN configuration alters the combustion and in-turn the Stage 1 Nozzle inlet profile. High fidelity CFD computations were performed to evaluate impact of these altered profile on HGP components, especially the thermal distribution and its impact on durability. Adiabatic wall temperatures obtained from CFD were used in developing heat transfer and flow temperature in the flow path locations. These were used to perform thermo-structural assessment for HGP components using ‘Finite Element Analysis’ (FEA) tools. With this evaluation, durability of HGP components in terms of LCF, creep was thoroughly assessed to ensure part life is meeting MI. Detailed high-fidelity FEA shows that, creep, oxidation, and ‘Low Cycle Fatigue’ (LCF) meet the design requirements for both life extension as well as the power increase conditions with DLN combustor profile. To gain confidence, MS5001PA durability results were benchmarked with field experience of ‘Standard’ (STD) and DLN configuration which shows coherent results with Creep and LCF. This gives confidence in thermal profile which was developed for PEK STD and DLN configurations. Based on detailed thermo-structural assessment, the maintenance factor was set to 1. This paper presents the latest methodology used in CFD for aero flow prediction and high-fidelity Finite Element (FE) assessment used for durability prediction of HGP components.
