Patent ID: 8616827

Claim:
A system for adjusting a clearance between blade tips of a turbine and a shroud assembly in a turbine engine, the system comprising: a first fluid passageway in fluid communication with a first source of fluid at a first pressure from a first compressor stage of a multi-stage compressor and extending between the first compressor stage and a shroud assembly of a turbine engine to direct a first stream of fluid at the first pressure to the shroud assembly; a second fluid passageway in fluid communication with a second source of fluid at a second pressure from a second compressor stage of the multi-stage compressor and extending between the second compressor stage and the shroud assembly to direct a second stream of fluid at the second pressure to the shroud assembly; a first valve positioned along said first fluid passageway and a second valve positioned along said second fluid passageway, each of said first and second valves moveable between open and closed configurations, said first valve controlled passively and directly by the first pressure of the first stream of fluid, said second valve controlled passively and directly by the second pressure of the second stream of fluid; wherein said first and second fluid passageways are in fluid communication with an interior region of said shroud assembly to direct said first and second streams of fluid into said interior region, said first and second fluid streams flow through said interior region of said shroud assembly to thermally expand and contract said shroud assembly to adjust the clearance between the blade tips and the shroud assembly; and wherein said first valve is moved toward said closed configuration when power production of the turbine engine is increased from a period of relatively low power production and/or wherein said second valve is moved toward said open configuration when power production of the turbine engine is increased from a period of relatively low power production.