| 摘要 |
PROBLEM TO BE SOLVED: To obtain sufficient cooling capacity, and also control a moving blade gap, by providing double shells; for surrounding turbine moving blades at every stage, and forming hollow annular chambers among the respective stage; on a turbine casing surrounding the moving blade part of a gas turbine, to flow cooling air in the chambers. SOLUTION: Double shells 12, for surrounding turbine moving blades 5a at every stage, and forming hollow annular chambers 11 among respective stage, are provided on a turbine casing 10 for surrounding the moving blade parts of a gas turbine. Cooling air is made to flow in a peripheral direction surrounding the turbine moving blades 5a, into the hollow annular chamber 11. This can give sufficient speed to the flow of the cooling air, thereby obtaining high cooling capacity. Also a gap control device 18 is provided which is adjusting the flow rate of the cooling air to control the moving blade gap. The double shell 12 is formed of outer and inner walls 13 and 14, to maintain them at low temperature by air in the hollow annular chmber 11, to provide containing capacity more than before, by the conbination of the outer and inner walls 13 and 14 and a shroud back plate 16. |
