turbine stator vane segments having leading edge impingement cooling circuits

摘要

Each nozzle vane of a turbine includes a leading edge cavity having an insert spaced from interior wall surfaces of the vane. The insert includes impingement holes for flowing cooling medium from within the insert through the holes for impingement cooling of the vane walls. The insert has a divider dividing the insert into first and second chambers. Cooling medium is supplied directly from a source to the first chamber for impingement cooling of the adjacent vane wall surfaces. Cooling medium at a substantially reduced pressure resulting from impingement cooling of the outer wall of the nozzle segment is supplied to the second chamber. The pressure of the cooling medium supplied the second chamber establishes the pressure difference between the interior and the exterior of the insert thereby affording increased cooling intensity of the impingement cooling flow.