GAS TURBINE NOZZLE SEGMENT AND METHOD OF COOLING BAND OF NOZZLE SEGMENT

摘要

PURPOSE: A gas turbine nozzle segment and method of cooling band of nozzle segment is provided to improve side wall cooling by arranging impingement cooling apertures directly through the inturned flanges of the side walls of the bands in order to reduce the distance traveled by the cooling steam flow. CONSTITUTION: A gas turbine nozzle segment has an outer and inner band(12). Each band includes a side wall(40), a cover(20) and an impingement plate(26) between the cover and a nozzle wall(18) defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity(24) for flow through apertures(30) of an impingement plate(22) to cool the nozzle wall. The side wall of the band and an inturned flange(42) define with the nozzle wall an undercut region(44). The inturned flange has a plurality of apertures(56) for directing cooling steam to cool the side wall between adjacent nozzle segments.