Late lean injection system

Abstract

A late lean injection system includes at least one fuel injector disposed proximate a combustion zone. Also included is at least one guide for directing an airflow from a region proximate a compressor discharge exit to the at least one fuel injector.

1 . A late lean injection system comprising:
 at least one fuel injector disposed proximate a combustion zone; and   at least one guide for directing an airflow from a region proximate a compressor discharge exit to the at least one fuel injector.   
     
     
         2 . The late lean injection system of  claim 1 , further comprising a transition duct. 
     
     
         3 . The late lean injection system of  claim 2 , wherein the at least one fuel injector is disposed proximate the transition duct and is configured to inject a fuel into the combustion zone. 
     
     
         4 . The late lean injection system of  claim 2 , further comprising a liner duct, wherein the at least one fuel injector is disposed proximate the liner duct and is configured to inject a fuel into the combustion zone. 
     
     
         5 . The late lean injection system of  claim 1 , wherein the at least one guide includes a first end disposed proximate the compressor discharge exit and a second end disposed proximate the at least one fuel injector. 
     
     
         6 . The late lean injection system of  claim 1 , wherein the at least one guide comprises a bend proximate the at least one fuel injector. 
     
     
         7 . The late lean injection system of  claim 6 , wherein the at least one guide comprises at least one straightening vane proximate the bend. 
     
     
         8 . The late lean injection system of  claim 1 , wherein the at least one guide is operably connected to a compressor discharge casing. 
     
     
         9 . The late lean injection system of  claim 1 , further comprising a plurality of fuel injectors, wherein the plurality of fuel injectors are circumferentially spaced at a single axial location. 
     
     
         10 . The late lean injection system of  claim 1 , further comprising a plurality of fuel injectors, wherein the plurality of fuel injectors are circumferentially spaced a plurality of axial locations. 
     
     
         11 . A late lean injection system comprising:
 a transition duct defining a transition interior, the transition duct having an end adapted for connection to a first turbine zone, and an opposite end;   a sleeve spaced radially outward of the transition duct and extending circumferentially around the transition duct;   at least one fuel injector configured to inject fuel into the transition interior; and   at least one guide for directing an airflow to the at least one fuel injector.   
     
     
         12 . The late lean injection system of  claim 11 , wherein the at least one guide includes a first end disposed proximate a compressor discharge exit and a second end disposed proximate the at least one fuel injector. 
     
     
         13 . The late lean injection system of  claim 12 , further comprising a liner duct disposed proximate the opposite end of the transition duct. 
     
     
         14 . The late lean injection system transition piece of  claim 11 , wherein the at least one guide comprises a bend proximate the at least one fuel injector. 
     
     
         15 . The late lean injection system transition piece of  claim 14 , wherein the at least one guide comprises at least one straightening vane proximate the bend. 
     
     
         16 . The late lean injection system transition piece of  claim 12 , wherein the at least one guide is operably connected to a compressor discharge casing. 
     
     
         17 . A late lean injection system comprising:
 a transition duct having an upstream end and a downstream end;   a liner duct disposed proximate the upstream end of the transition duct;   a flowsleeve spaced radially outward of the liner duct and extending circumferentially around the liner duct;   at least one fuel injector disposed proximate at least one of the transition duct and the liner duct; and   at least one guide for directing an airflow from a region proximate a compressor discharge exit to the at least one fuel injector.   
     
     
         18 . The late lean injection system of  claim 17 , wherein the at least one guide includes a first end disposed proximate the compressor discharge exit and a second end disposed proximate the at least one fuel injector. 
     
     
         19 . The late lean injection system of  claim 17 , wherein the at least one guide comprises a bend proximate the at least one fuel injector. 
     
     
         20 . The late lean injection system of  claim 17 , wherein the at least one guide is operably connected to a compressor discharge casing.