TURBINE STATOR VANE SEGMENT HAVING CLOSED COOLING CIRCUIT

摘要

A second stage stator vane segment includes outer and inner walls integrally cast with a pair of vanes and hooks for locating the segments on the inner shell of a turbine. Each of the outer and inner walls is divided into compartments which are in turn divided into inner and outer chambers by impingement plates. Cooling steam inlet to the outer side wall flows into the outer chambers and through the openings of the impingement plate for steaming cooling the outer side wall. Steam flows through cavities in the vane for impingement steam cooling the vane and into compartments of the inner side wall. Impingement plates in the inner side wall direct the steam for impingement cooling of the inner side wall and return through a cavity in the vane for further impingement-cooling of the vane and flow to a steam exhaust. The trailing edge of the vane is air cooled.