Counterflow injection mechanism having coaxial fuel-air passages

Abstract

In accordance with certain embodiments, a system includes a fuel-air injection mechanism having coaxial fuel and air passages leading to fuel and air injection openings. The fuel and air injection openings are configured to reside at an off-axis position of a gas turbine combustor, and the fuel and air injection openings are configured to orient in an injection direction not aligned with a flow direction through the gas turbine combustor to a turbine.

1 . A system, comprising: 
 a fuel-air injection mechanism comprising coaxial fuel and air passages leading to fuel and air injection openings, wherein the fuel and air injection openings are configured to reside at an off-axis position of a gas turbine combustor, and the fuel and air injection openings are configured to orient in an injection direction not aligned with a flow direction through the gas turbine combustor to a turbine.    
   
   
       2 . The system of  claim 1 , wherein the fuel and air injection openings are generally coaxial with one another.  
   
   
       3 . The system of  claim 1 , wherein the fuel and air injection openings are offset from one another along a common axis of the coaxial fuel and air passages.  
   
   
       4 . The system of  claim 1 , wherein the fuel and air injection openings are oriented crosswise relative to one another.  
   
   
       5 . The system of  claim 4 , wherein the fuel injection opening is disposed in a circumferential wall of an air passage of the coaxial fuel and air passages.  
   
   
       6 . The system of  claim 4 , wherein the fuel injection opening is disposed in a circumferential wall of a fuel passage of the coaxial fuel and air passages.  
   
   
       7 . The system of  claim 1 , wherein the coaxial fuel and air passages comprise a fuel swirling mechanism, or an air swirling mechanism, or counter swirling mechanisms, or a combination thereof.  
   
   
       8 . The system of  claim 1 , comprising a plurality of fuel-air injection mechanisms, including the fuel-air injection mechanism, disposed at multiple radial positions in a circumferential arrangement.  
   
   
       9 . The system of  claim 8 , wherein the plurality of fuel-air injection mechanisms is oriented in a generally converging relationship.  
   
   
       10 . The system of  claim 1 , comprising the gas turbine combustor.  
   
   
       11 . The system of  claim 10 , wherein the gas turbine combustor comprises a combustion liner having an inner casing and an outer casing, an air flow path between and along the inner and outer casings, and the air flow path extends to the fuel-air injection mechanism.  
   
   
       12 . The system of  claim 10 , comprising a gas turbine engine having the turbine and a compressor coupled to the gas turbine combustor.  
   
   
       13 . The system of  claim 12 , comprising a power generator, or a propulsion system, or a vehicle, or a combinations thereof coupled to the gas turbine engine.  
   
   
       14 . A system, comprising: 
 a gas turbine combustor, comprising: 
 a combustion liner having a generally lengthwise flow axis extending from a stagnation zone to a turbine nozzle; and  
 a counterflow fuel-air injector disposed in the combustion liner at one or more intermediate positions between the stagnation zone and the turbine nozzle, wherein the counterflow fuel-air injector comprises coaxial fuel and air passages extending to fuel and air injection openings not aligned with a flow direction from the stagnation zone to the turbine nozzle.  
   
   
   
       15 . The system of  claim 14 , wherein the fuel and air injection openings are generally coaxial with one another.  
   
   
       16 . The system of  claim 14 , wherein the fuel and air injection openings are oriented crosswise relative to one another.  
   
   
       17 . The system of  claim 16 , wherein the fuel injection opening is disposed in a circumferential wall of an air passage of the coaxial fuel and air passages, or the fuel injection opening is disposed in another circumferential wall of a fuel passage of the coaxial fuel and air passages, or a combination thereof.  
   
   
       18 . The system of  claim 14 , wherein the coaxial fuel and air passages comprise a fuel swirling mechanism, or an air swirling mechanism, or counter swirling mechanisms, or a combination thereof.  
   
   
       19 . The system of  claim 14 , wherein the combustion liner comprises a hollow annular wall having a perforated outer casing disposed about a substantially solid inner casing, and an air circulation path extends throughout the hollow annular wall to air passages of the coaxial fuel and air passages.  
   
   
       20 . The system of  claim 14 , comprising a gas turbine engine including a turbine and a compressor coupled to the gas turbine combustor.  
   
   
       21 . The system of  claim 14 , wherein the fuel and air injection openings are oriented in a generally converging relationship toward the stagnation zone.  
   
   
       22 . The system of  claim 14 , wherein the counterflow fuel-air injector is disposed in a generally off-axis configuration relative to the generally lengthwise flow axis.  
   
   
       23 . A method, comprising: 
 coaxially flowing fuel and air to a counterflow fuel-air injector oriented in a generally counterflow direction relative to a generally lengthwise flow axis from a stagnation zone to a turbine nozzle of a gas turbine combustor.    
   
   
       24 . The method of  claim 23 , wherein coaxially flowing fuel and air comprises coaxially injecting fuel and air through coaxial fuel-air openings in the counterflow fuel-air injector.  
   
   
       25 . The method of  claim 23 , wherein coaxially flowing fuel and air comprises radially injecting fuel from a fuel port into an air passage.  
   
   
       26 . The method of  claim 23 , wherein coaxially flowing fuel and air comprises swirling the air, or swirling the fuel, or swirling the fuel and air in a common rotational direction, or counterswirling the fuel and air in opposite rotational directions.  
   
   
       27 . The method of  claim 23 , wherein coaxially flowing fuel and air comprises injecting fuel and air from a plurality of counterflow fuel-air injectors oriented to converge toward the stagnation zone.  
   
   
       28 . The method of  claim 23 , wherein coaxially flowing fuel and air comprises circulating air through a hollow annular combustion liner and injecting the air into the gas turbine combustor along with fuel.