System for injecting a liquid fuel into a combustion gas flow field

Abstract

A system for injecting a liquid fuel into a combustion gas flow field includes an annular liner that defines a combustion gas flow path. The annular liner includes an inner wall, an outer wall and a fuel injector opening that extends through the inner wall and the outer wall. The system further includes a gas fuel injector that is coaxially aligned with the fuel injector opening. The gas fuel injector includes an upstream end and a downstream end. The downstream end terminates substantially adjacent to the inner wall. A dilution air passage is at least partially defined by the gas fuel injector. A liquid fuel injector extends partially through the dilution air passage. The liquid fuel injector includes an injection end that terminates upstream from the inner wall.

What is claimed is: 
     
         1 . A system for injecting a liquid fuel into a combustion gas flow field, comprising:
 a. an annular liner that defines a combustion gas flow path, the annular liner having an inner wall, an outer wall and a fuel injector opening that extends through the inner wall and the outer wall;   b. a gas fuel injector coaxially aligned with the fuel injector opening, the gas fuel injector having an upstream end and a downstream end, wherein the downstream end terminates substantially adjacent to the inner wall;   c. a dilution air passage at least partially defined by the gas fuel injector, wherein the dilution air passage provides for fluid communication through the annular liner into the combustion gas flow path; and   d. a liquid fuel injector that extends partially through the dilution air passage, the liquid fuel injector having an injection end that terminates upstream from the inner wall.   
     
     
         2 . The system as in  claim 1 , wherein the liquid fuel injector further comprises a plurality of liquid fuel injection ports disposed at the injection end. 
     
     
         3 . The system as in  claim 1 , wherein the liquid fuel injector further comprises a first liquid fuel injection port, a second liquid fuel injection port and a third liquid fuel injection port arranged in a triangular array across the injection end. 
     
     
         4 . The system as in  claim 3 , wherein the first liquid fuel injection port is spaced an equal distance from the second liquid fuel injection port and from the third liquid fuel injection port. 
     
     
         5 . The system as in  claim 3 , wherein the first liquid fuel injection port is positioned upstream from the second liquid fuel injection port and the third liquid fuel injection port with respect to a direction of flow of combustion gases within the combustion gas flow path. 
     
     
         6 . The system as in  claim 1 , wherein the injection end of the liquid fuel injector terminates between the inner wall and the outer wall of the annular liner. 
     
     
         7 . The system as in  claim 1 , wherein the upstream end of the gas fuel injector defines an inlet of the dilution air passage and the downstream end defines an outlet of the dilution air passage. 
     
     
         8 . The system as in  claim 1 , wherein the gas fuel injector comprises a gas fuel plenum that extends circumferentially around the upstream end and a plurality of gas fuel ports that provide for fluid communication between the gas fuel plenum and the dilution flow passage. 
     
     
         9 . A system for injecting a liquid fuel into a combustion gas flow field, comprising:
 a. an annular liner that defines a combustion gas flow path within the combustor, the annular liner having an inner wall, an outer wall and a fuel injector opening; and   b. a fuel injector coaxially aligned with the fuel injector opening, the fuel injector comprising:
 i. an annular main body having an upstream end and a downstream end, wherein the annular main body defines a dilution air passage that provides for fluid communication through the fuel injector into the combustion gas flow path; 
 ii. a gas fuel plenum defined within the main body; 
 iii. a liquid fuel plenum defined within the main body; and 
 iv. a plurality of liquid fuel injectors that extend from the main body into the dilution air passage to provide for fluid communication between the liquid fuel plenum and the dilution air passage, wherein the plurality of liquid fuel injectors terminate upstream from the inner wall of the annular liner. 
   
     
     
         10 . The system as in  claim 9 , wherein the plurality of liquid fuel injectors comprises a first liquid fuel injector, a second liquid fuel injector and a third liquid fuel injector arranged in a triangular array within the dilution air passage. 
     
     
         11 . The system as in  claim 10 , wherein the first liquid fuel injector is positioned upstream from the second liquid fuel injector and the third liquid fuel injector with respect to a direction of flow of combustion gases within the combustion gas flow path. 
     
     
         12 . The system as in  claim 10 , wherein the first liquid fuel injector, the second liquid fuel injector and the third liquid fuel injector are arranged in a triangular array within the dilution air passage. 
     
     
         13 . The system as in  claim 10 , wherein the first liquid fuel injector is spaced an equal distance from the second liquid fuel injector and the third liquid fuel injector. 
     
     
         14 . A gas turbine, comprising:
 a. a compressor;   b. a combustor disposed downstream from the compressor, the combustor having an axially extending fuel nozzle that extends downstream from the end cover, a combustion gas flow path defined downstream from the axially extending fuel nozzle and an annular liner that at least partially defines the combustion gas flow path within the combustor, the annular liner having an inner wall, an outer wall and a fuel injector opening;   c. a turbine disposed downstream from the combustor; and   d. wherein the combustor further includes a system for injecting a liquid fuel into a combustion gas flow field within the combusor downstream from the axially extending fuel nozzle, the system comprising:
 i. a dilution air passage that provides for fluid communication through the annular liner into the combustion gas flow path; and 
 ii. a plurality of liquid fuel injectors disposed within the dilution air passage, wherein the plurality of liquid fuel injectors terminate within the dilution air passage upstream from the inner wall of the annular liner. 
   
     
     
         15 . The gas turbine as in  claim 14 , wherein the system comprises a gas fuel injector disposed coaxially within the fuel injector opening, the gas fuel injector having an upstream end and a downstream end, wherein the downstream end terminates substantially adjacent to the inner wall. 
     
     
         16 . The gas turbine as in  claim 15 , wherein the liquid fuel injector includes an injection end that terminates adjacent to or upstream from the downstream end of the gas fuel injector. 
     
     
         17 . The gas turbine as in  claim 14 , wherein the liquid fuel injector further comprises a first liquid fuel injection port, a second liquid fuel injection port and a third liquid fuel injection port that are arranged in a triangular array across the injection end, wherein the first liquid fuel injection port is positioned upstream from the second liquid fuel injection port and the third liquid fuel injection port with respect to a flow of combustion gases that flow through the combustion gas flow path. 
     
     
         18 . The gas turbine as in  claim 18 , wherein the system further comprises:
 a. an annular main body having an upstream end and a downstream end, wherein the annular main body defines the dilution air passage;   b. a gas fuel plenum that extends within the main body;   c. a liquid fuel plenum that extends within the main body; and   d. wherein the at least one liquid fuel injector extends from the main body into the dilution air passage to provide for fluid communication between the liquid fuel plenum and the dilution air passage.   
     
     
         19 . The gas turbine as in  claim 18 , wherein the at least one liquid fuel injector comprises of a first liquid fuel injector, a second liquid fuel injector and a third liquid fuel injector arranged in a triangular array within the dilution air passage. 
     
     
         20 . The gas turbine as in  claim 18 , wherein the first liquid fuel injector is positioned upstream from the second liquid fuel injector and the third liquid fuel injector with respect to a flow of the combustion gases.