Cooling system for nozzle segment platform edges

In a turbine having an axis, a plurality of nozzle segments arranged in a circumferential array about said axis, each of said nozzle segments including inner and outer platforms and at least one nozzle vane extending therebetween, said platforms having side edges extending generally parallel to the axis and in generally circumferential registration with the side edges of platforms of adjacent nozzle segments;

• a cooling system for at least one of the platforms of each segment including a source of a cooling medium, a first elongated plenum extending along at least one of the side edges of said one platform, a plurality of inlet passages in communication between said source and said plenum at spaced locations along said plenum, a plurality of outlet passages in communication with said plenum at spaced locations along said plenum and having outlet openings through said one side edge of said one platform at spaced locations therealong for flowing the cooling medium toward the side edge of a platform of an adjacent nozzle segment, and passageways in communication with said plenum and a plurality of film cooling holes disposed along a surface of said platform for supplying the cooling medium along and film cooling said platform surface, said inlet passages, said outlet passages and said passageways being arranged such that said inlet passages do not have direct line-of-sight flow of the cooling medium into the outlet passages and said passageways.

A nozzle segment for a turbine having an axis, comprising:

• inner and outer platforms and at least one nozzle vane extending therebetween, said platforms having opposite side edges adjacent respective suction and pressure sides of the vane;
• a cooling system for at least one of said platforms including a source of a cooling medium, first and second elongated plenums extending along the opposite side edges of said one platform, a plurality of first and second inlet passages in communication between said source and said first and second plenums, respectively, at spaced locations therealong, a plurality of first and second outlet passages in communication with said first and second plenums, respectively, at spaced locations along said plenums and having outlet openings through respective opposite side edges of said one platform at spaced locations therealong, and a plurality of first and second passageways in communication with said first and second plenums, respectively, and a plurality of film cooling holes disposed along a surface of said one platform for supplying the cooling medium along and film cooling said platform surface;
• said first and second plenums extending along respective side edges of said platform adjacent suction and pressure sides of said vane with said first plenum spaced closer to a side edge of said platform on said suction side of said vane than said second plenum is spaced from the side edge of the platform on said pressure side of said vane.