KÜHLUNG EINER STATORSCHAUFEL BEI EINER GASTURBINE

摘要

In a cooled gas turbine stationary blade, both steam cooling and air cooling are utilized to reduce the amount of cooling air. In the stationary blade having outer and inner shrouds 1, 21 and steam passages 10A, 10B, 10C, 10D and 10E which are communicated with each other and in which a sealing air feed tube 2 passes through a central portion thereof, steam covers 3, 4 are provided in the outer shroud 1, and steam S is introduced from a steam feed port 5. The steam S passes through serpentine passages 10A to 10E and is recovered from the steam outlet 12 after cooling the central portion of the outer shroud 1 by means of an impingement plate 8. Apportion of the steam of the passage 10A is introduced from the impingement plate 25 to a steam sump 24 to cool the central portion of the inner shroud 21 and pass through the passage 10D to be recovered from the steam outlet port 12. On the other hand, cooling air is fed from cooling air feed ports 6 and 26 to peripheral portions of the outer and inner shrouds 1, 21, and is discharged to the outside from the rear sides thereof, respectively, and the cooling air is further fed from a cooling air feeding port 7 to the passage 10E on the rear edge of the blade to cool the rear edge of the blade. Only the narrow portions where it is difficult for the steam to pass are air-cooled to thereby reduce the amount of the cooling air.