Advanced Seal Development for Large Industrial Gas Turbines

Combined-cycle plants powered by large utility gas turbines have become the system of choice in the power generation industry. This change has increased the emphasis hi improving performance and decreasing harmful emissions of large gas turbine engines and is the focus of the U.S. Department of Energy's (DOE) Advanced Turbine Systems (ATS) Program. One of the critical areas being addressed is improving static and dynamic sealing, because modest decreases in leakage flows can have significant effects on engine performance. For many dynamic seal locations hi Westinghouse's ATS gas turbine engine, brush seals are being considered as a replacement for labyrinth seals to reduce leakage flows. Brush seal development was initiated two years ago and significant progress has been made. Brush seal designs for the turbine interstage and compressor diaphragm locations have been established based on tribology and subscale rig testing results. Fullscale turbine interstage and compressor diaphragm brush seals have been fabricated for validation hi component rigs and operating engines. Brush seal development is continuing for the turbine front and run locations. Also, development is in progress of a low leakage, non-contact, dry gas face seal for the rear of the ATS engine turbine rotor.