Systems and methods for coherence reduction in combustion system

Abstract

A system includes a gas turbine engine having a first combustor and a second combustor. The first combustor includes a first set of fuel nozzles and a first plurality of injection pegs. The first plurality of injection pegs are disposed in a first configuration upstream of the first set of fuel nozzles, along a first fuel path, and the first plurality of injection pegs are configured to route a fuel to the first set of fuel nozzles. The system further includes a second combustor having a second set of fuel nozzles and a second plurality of injection pegs. The second plurality of injection pegs are disposed in a second configuration upstream of the second set of fuel nozzles, along a second fuel path, and the second plurality of injection pegs are configured to route the fuel to the second set of fuel nozzles. The second configuration has at least one difference relative to the first configuration.

1 . A system, comprising:
 a gas turbine engine, comprising:
 a first combustor having a first set of fuel nozzles and a first plurality of injection pegs, wherein the first plurality of injection pegs are disposed in a first configuration upstream of the first set of fuel nozzles, along a first fuel path, and the first plurality of injection pegs are configured to route a fuel to the first set of fuel nozzles; and 
 a second combustor having a second set of fuel nozzles and a second plurality of injection pegs, wherein the second plurality of injection pegs are disposed in a second configuration upstream of the second set of fuel nozzles, along a second fuel path, and the second plurality of injection pegs are configured to route the fuel to the second set of fuel nozzles, and the second configuration has at least one difference relative to the first configuration. 
   
     
     
         2 . The system of  claim 1 , wherein the at least one difference is configured to reduce coherence between the first combustor and the second combustor by varying a first convective time of the first set of injection pegs relative to a second convective time of the second set of injection pegs. 
     
     
         3 . The system of  claim 1 , wherein the at least one difference is configured to vary combustion dynamics between the first combustor and the second combustor by varying a first ratio of an air-fuel mixture of the first set of fuel nozzles relative to a second ratio of the air-fuel mixture of the second set of fuel nozzles. 
     
     
         4 . The system of  claim 1 , wherein the at least one difference between the first plurality of injection pegs and the second plurality of injection pegs comprises a difference between at least one injection peg of the first plurality of injection pegs and at least one injection peg of the second plurality of injection pegs. 
     
     
         5 . The system of  claim 4 , wherein the at least one difference between the first plurality of injection pegs and the second plurality of injection pegs comprises at least one of a different axial configuration, a different circumferential configuration, or a different geometry, or any combination thereof. 
     
     
         6 . The system of  claim 5 , wherein the different axial configuration comprises at least one of a different axial placement, a different axial location, a different axial position, or a different axial arrangement, or any combination thereof, between one or more axes of the first or second combustor. 
     
     
         7 . The system of  claim 5 , wherein the different circumferential configuration comprises at least one of a different circumferential placement, a different circumferential location, a different circumferential position, or a different circumferential arrangement, or any combination thereof, between a first axis of the first and second combustor. 
     
     
         8 . The system of  claim 5 , wherein the different geometry comprises at least one of a different angle, a different size, or a different shape, or any combination thereof, between the first plurality of injection pegs and the second plurality of injection pegs. 
     
     
         9 . The system of  claim 1 , wherein the first set of fuel nozzles are arranged into one or more fuel circuits, and wherein a first injection peg and a second injection peg of the first plurality of injection pegs are associated with a first fuel circuit and a second fuel circuit of the one or more fuel circuits, respectively. 
     
     
         10 . The system of  claim 9 , wherein the first injection peg comprises at least one difference relative to the second injection peg, and wherein the at least one difference comprises a different axial configuration, a different circumferential configuration, a different geometry, or any combination thereof. 
     
     
         11 . A system, comprising:
 a first turbine combustor, comprising:
 a first plurality of fuel nozzles configured to route an air-fuel mixture to a combustion chamber of the first turbine combustor, wherein the first plurality of fuel nozzles comprises a first set of fuel nozzles and a second set of fuel nozzles; and 
 a first plurality of injection pegs configured to route a fuel to the first plurality of fuel nozzles, wherein the first plurality of injection pegs comprises a first set of injection pegs associated with the first set of fuel nozzles and a second set of injection pegs associated with the second set of fuel nozzles, and the first set of injection pegs has at least one difference relative to the second set of injection pegs. 
   
     
     
         12 . The system of  claim 11 , wherein the at least one difference is configured to reduce coherence between the first combustor and the second combustor by varying a first convective time of the first set of injection pegs relative to a second convective time of the second set of injection pegs. 
     
     
         13 . The system of  claim 11 , comprising a second turbine combustor comprising:
 a second plurality of fuel nozzles configured to route the air-fuel mixture to a second combustion chamber of the second turbine combustor, wherein the second plurality of fuel nozzles comprises a third set of fuel nozzles and a fourth set of fuel nozzles; and   a second plurality of injection pegs configured to route the fuel to the second plurality of fuel nozzles, wherein the second plurality of injection pegs comprises a third set of injection pegs associated with the third set of fuel nozzles and a fourth set of injection pegs associated with the fourth set of fuel nozzles.   
     
     
         14 . The system of  claim 13 , wherein the first set of injection pegs or the second set of injection pegs comprises at least one difference relative to the third set of injection pegs or the fourth set of injection pegs. 
     
     
         15 . The system of  claim 14 , wherein the at least one difference is configured to vary combustion dynamics between the first combustor and the second combustor by varying a first ratio of an air-fuel mixture of the first set of fuel nozzles relative to a second ratio of the air-fuel mixture of the second set of fuel nozzles. 
     
     
         16 . The system of  claim 11 , wherein the at least one difference between the first set of injection pegs and the second set of injection pegs comprises a different axial configuration, a different circumferential configuration, a different geometry, or any combination thereof. 
     
     
         17 . The system of  claim 11 , wherein the first set of injection pegs or the second set of injection pegs comprises a set of zero injection pegs. 
     
     
         18 . A method, comprising:
 controlling a first combustion dynamic of a first combustor or a first convective time of a first set of injection pegs of the first combustor with a first configuration of a first plurality of injection pegs disposed upstream of the first set of fuel nozzles along a first fuel path; and   controlling a second combustion dynamic of a second combustor or a second convective time of a second set of injection pegs of the second combustor with a second configuration of a second plurality of injection pegs disposed upstream of the second set of fuel nozzles along a second fuel path, wherein the second plurality of injection pegs has at least one difference relative to the first plurality of injection pegs.   
     
     
         19 . The method of  claim 18 , wherein the at least one difference comprises a different axial configuration, a different circumferential configuration, a different geometry, or any combination thereof. 
     
     
         20 . The method of  claim 18 , wherein the at least one difference between the first plurality of injection pegs and the second plurality of injection pegs is configured to reduce modal coupling between the first combustor and the second combustor.