Advanced seals for industrial turbine applications: design approach and static seal development

Changes in the market place are imposing increasing demands to improve efficiency (decreasing heat rate) and power output for both existing and new industrial turbines. The improvement is to be done while maintaining or decreasing emission levels. This demand has led to extensive efforts to improve the performance of the various components in industrial gas turbines, steam turbines, compressors, and generators. One of the critical areas being addressed is reducing the parasitic leakage flows through the various static and dynamic seals. Implementing advanced seals into industrial turbines has progressed well over the last several years, with significant operating performance gains achieved. Advanced static seals have been placed in gas-turbine hot gas-path junctions and steam-turbine packing ring segment end gaps. The status of efforts to develop and implement advanced static seals in industrial turbines is summarized. The design approach following design-for-six-sigma methodology is summarized, and the development efforts for each static seal type are presented.