Session: 25-02 Component Assessment

Paper Number: 153813

A Novel Methodology to Test Metallic Sealing Rings for Variable Guide Vanes 

Among the design features included in axial expanders to achieve improved performance and operational flexibility, Nozzle Guide Vanes (NGVs) are a common topic of research and development. In the last years these components, which were already characterized by an intrinsic complexity, have been challenged to achieve higher efficiency and durability performances. Therefore, deeper experimental campaigns addressing the mechanical behavior of these assemblies are being performed. The state-of-the-art test bench targets actual full-scale geometries by operating at high temperature and by recreating the actual load and NGV motion. This paper focuses on the validation of sealing solutions introduced to avoid leakages from the flow-path through the housing of the NGV stem. The proposed solution consists in the design of a novel customized bench addressing the sealing system performance and durability. After summarizing different sealing concepts to be tested, the commissioning and the results of the performed experimental campaign are detailed, with particular focus on metallic sealing rings solutions. The bench is designed to accomplish continuous endurance testing of the contact pair between sealing ring, stem and external housing at high temperature targeting actual loading conditions. Details are given regarding the design of the bench components which allow testing of sealing rings different by size and manufacturing technology. The design verifications needed for the proper bench operation are presented. The sealing capability of these solution is compared showing limited losses compatible with working conditions even in “worn” scenarios.

Presenting Author: Stella Grazia Tomasello Baker Hughes

Presenting Author Biography: Stella Tomasello is a Steam Turbine and axial expanders NPD Mechanical Design Engineer at Baker Hughes in Florence, Italy. During her Ph.D. at the University of Florence, she focused on studying and modelling the aerothermal phenomena related to the combustor-turbine interaction in modern gas turbines, employing RANS and SBES as CFD methods.

Authors:

Stella Grazia Tomasello Baker Hughes
Federico Bucciarelli Baker Hughes
Enrico Giusti Baker Hughes
Damaso Checcacci Baker Hughes