US 5,253,976 A · Integrated steam and air cooling for combined cycle gas turbines

Abstract

A steam or air-cooled combined cycle gas turbine includes first and second turbine stages and a second nozzle stage disposed about a spacer between the turbine stages. Cooling steam is passed through the nozzle vanes radially inwardly and through the seal between the spacer and the nozzle stage into a pair of chambers. Inlet ports are carried by the first and second-stage turbines for conducting the steam through both single and multi-pass circuits in the turbine blades to cool the blades. Steam is inlet along the axis of the turbine for mixing with the steam inlet past the nozzle stage and spacer seal. Air is inlet adjacent the axis of the turbine and a valve selectively opens and closes an air inlet for admitting air into the chambers. When the turbine is in a start-up mode or steam is not available, the valve is open to admit air into the chambers to supply cooling air to the turbine blades. When steam is available, the valve is closed and the turbine blades are steam cooled.

Claims24

Dependent claims

A cooling system for a gas turbine comprising:

a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine;
said turbine blades each having at least one interior passage extending from an inlet port adjacent a root portion of the blade to an outlet port adjacent a tip portion of the blade;
a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow;
each said vane having at least one interior passage having an inlet and an outlet adjacent respective radially outer and inner end portions of said vane for passing steam from said inlet radially inwardly through said vane to said outlet;
a spacer between said turbine stages and rotatable therewith;
at least one passageway through said spacer and in communication with said outlets for said vanes and said inlet ports for said turbine blades for flowing steam from said nozzle vanes to said turbine blades, whereby steam may flow through said passages in said blades to cool said blades.

3 more elements

A blade for the turbine stage of a gas turbine, comprising:

a body having a discrete length and a general airfoil shape, with pressure and suction sides, tip and root portions and leading and trailing edges;
a plurality of discrete internal passages extending lengthwise along said blade having inlet and outlet ports adjacent said root and tip portions, respectively, for flowing cooling fluid through the blade including a pair of single-pass passages adjacent said leading and trailing edges, respectively, and first and second multi-pass passages intermediate said leading and trailing edges and said single-pass passages;
each of said first and second multi-pass passages having first, second and third discrete passageways for flowing cooling fluid from said root portion toward said tip portion, back toward said root portion and finally toward said tip portion, respectively, to cool intermediate portions of said blade, said third passageways disposed adjacent one another, said first and second passageways of said first multi-pass passage being disposed between the leading edge and said third passageway thereof, said first and second passageways of said second multi-pass passage being, disposed between the trailing edge and said third passageway thereof whereby cooling fluid flows through said first and second passages generally toward one another for exit through outlets thereof substantially medially of the airfoil-shaped body and at said tip portion of said blade.

Dependencies are inferred from the claim text.

Integrated steam and air cooling for combined cycle gas turbines

Life of this patent

Integrated steam and air cooling for combined cycle gas turbines

Life of this patent

Abstract

Claims24