| 摘要 |
PROBLEM TO BE SOLVED: To form a clearance most favorably by controlling the change by a thermal elongation of the clearance in operation by cooling the air for sealing, on the seal clearance control system between the stages of stationary blades of a turbine. SOLUTION: The air from a compressor is cooled by a cooler 12 and introduced into the cavity 26 in an inside shroud 23 through an outside shroud 22 and the tube 28 in a stationary blade 21 and streamed out from the seal part 36 to the outside through a space 34 and streamed out from the seal part 37 to the outside through a seal ring 25 and a space 35 and seals the inside of the inside shroud 23 from a high temperature combustion gas. The clearanceδH between a stationary part and a rotary part is changed by a thermal elongation, but always monitored by a clearance measurement sensor 14. A control device 10 opens a flow rate adjust valve 11 whenδH is big and bypasses the air not through the cooler 12 and closes the valve 11 whenδH is small and the thermal elongation is controlled so thatδH is always favorable. Therefore, the seal performance is improved so that the contact can be avoided.
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