Steam and air cooling for stator stage of a turbine.

摘要

The second-stage nozzles include a plurality of stator vanes 10 having first, second, third, fourth and fifth passages 40, 42, 44, 46 and 48, respectively, for cooling the vanes. The first and fourth passages have a steam inlet along an outer sidewall 14 and a junction box 70 along the inner sidewall 12 for returning steam to the second passage 42. The third passage 44 has a contour corresponding to the contour of the leading edge and impingement steam is directed through openings in a partition 52, cooling the leading edge. Steam flows from the third passage 44 directly into the return passage 42 and also into a channel 64 for cooling the inner sidewall 12. Cooling air flows through fifth passage 48 radially inwardly through the inner sidewall 12 into a cavity 72 in the diaphragm 32 for flow axially outwardly into wheel. cavities 86 and 88.