Recuperative steam cooled gas turbine method and apparatus
AssigneeWestinghouse Electric Corp.
InventorMichael S. Briesch
Life of this patent
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Abstract
A recuperative steam cooled gas turbine in which steam used to cool the turbine section is subsequently introduced into the combustors, thereby recuperating the heat absorbed by the steam during cooling. The steam is generated in a heat recovery steam generator and then directed to a manifold within the turbine shell. From the manifold, the steam flows through passages formed within the interior of the vane by a baffle, thereby cooling the vane and heating the steam. The steam is then discharged from the vane into a chamber that collects the compressed air from the compressor. In the chamber, the heated steam mixes with the compressed air and the air/steam mixture then flows into the combustors, where it serves to reduce NOx generation from the combustors and increase power output from the turbine.
Claims14
A gas turbine power plant, comprising:
- a) a compressor for producing of flow of compressed air;
- b) means for directing at least a first portion of said flow of said compressed to a combustor having means for producing a hot compressed gas by burning a fuel in said first portion of said flow of compressed air therein;
- c) a turbine for expanding said hot compressed gas from said combustor so as to produce an expanded gas and shaft power, said turbine having a plurality of airfoils for directing the flow of said hot compressed gas through said turbine;
- d) means for directing a flow of steam in a first direction through said airfoils, wherein heat is transferred from said airfoils to said steam, thereby cooling said airfoils and heating said steam;
- e) means for directing said heated steam from said airfoils to said combustor, whereby said heated steam is further heated in said combustor and forms a portion of said hot compressed gas produced by said combustor;
- and
- f) means for directing a second portion of said flow of compressed air in a second direction through said airfoils only when said flow of steam does not flow through said airfoils.
In a gas turbine power plant having a compressor for producing compressed air and a combustor for burning a fuel in said compressed air to produce a hot compressed NO.sub.x bearing gas and a turbine for expanding said hot compressed gas so as to produce shaft power, said turbine having a plurality of airfoils disposed therein, a method of (i) increasing said shaft power output produced by said turbine, (ii) reducing NO.sub.x concentration in said hot compressed gas, and (iii) cooling said airfoils, comprising the steps of:
- a) generating a flow of steam;
- b) directing at least a portion of said flow of steam to said airfoils and flowing said steam therethrough in a first direction, thereby cooling said airfoils and heating said steam;
- c) directing a portion of said compressed air through said airfoils in a second direction;
- d) directing said flow of heated steam from said airfoils to said combustor for mixing therein with said hot compressed NO.sub.x bearing gas, thereby quenching said gas and reducing NO.sub.x concentration in said gas and producing a hot gas/steam mixture;
- and
- e) flowing said hot gas/steam mixture through said turbine so as to produce shaft power therein, whereby said hot gas/steam mixture flows over said airfoils, thereby transferring heat thereto for heating said steam, the second direction being opposite from the first direction.
Dependencies are inferred from the claim text.