Methods and systems to facilitate operating within flame-holding margin

Abstract

A method to facilitate controlling flame-holding margins in a turbine engine is provided. The method includes coupling at least one turbine nozzle segment within the turbine engine, wherein the at least one turbine nozzle segment includes at least one vane extending between an inner band and an outer band. The method also includes positioning at least one fuel injection orifice in a surface of the at least one vane, channeling a fuel through the at least one fuel injection orifice into a compressed fluid flow to establish a jet penetration height, and defining an operating window by adjusting an operating parameter of the fuel to reduce the jet penetration height and to facilitate reducing the flame-holding margins.

1 . A method to facilitate operating within flame-holding margins in a turbine engine, said method comprising:
 coupling at least one turbine nozzle segment within the turbine engine, wherein the at least one turbine nozzle segment includes at least one vane extending between an inner band and an outer band;   positioning at least one fuel injection orifice in a surface of the at least one vane;   channeling a fuel through the at least one fuel injection orifice into a compressed fluid flow to establish a jet penetration height; and   defining an operating window by adjusting an operating parameter of the fuel to reduce the jet penetration height and to facilitate increasing the flame-holding margins.   
   
   
       2 . A method in accordance with  claim 1  further comprising:
 sizing the at least one fuel injection orifice to operate using a design fuel; and   channeling a non-design fuel through the at least one fuel injection orifice.   
   
   
       3 . A method in accordance with  claim 1  wherein defining an operating window by adjusting a parameter of the fuel further comprises adjusting a density of the fuel by changing a temperature of the fuel. 
   
   
       4 . A method in accordance with  claim 3  further comprising changing the temperature of the fuel to facilitate altering a momentum ratio of the fuel. 
   
   
       5 . A method in accordance with  claim 1  wherein defining an operating window by adjusting a parameter of the fuel further comprises adjusting a fuel nozzle pressure ratio range by changing a temperature of the fuel. 
   
   
       6 . A method in accordance with  claim 1  wherein channeling a fuel through the at least one fuel injection orifice further comprises channeling a non-design fuel having a modified wobbe index that is lower than a modified wobbe index of the design fuel through the at least one fuel injection orifice. 
   
   
       7 . A method in accordance with  claim 1  wherein channeling a fuel through the at least one fuel injection orifice further comprises:
 channeling a non-design fuel through the at least one fuel injection orifice, wherein the non-design fuel has a higher modified wobbe index (MWI) than an MWI of the design fuel; and   at least one of heating and cooling the non-design fuel.   
   
   
       8 . A method in accordance with  claim 1  wherein channeling a fuel through the at least one fuel injection orifice further comprises channeling a non-design fuel through the at least one fuel injection orifice, wherein the non-design fuel is at least one of liquefied natural gas, syngas and process gas. 
   
   
       9 . A system to facilitate operating within flame-holding margins in a turbine engine, said system comprising:
 at least one turbine nozzle segment coupled within the turbine engine, said at least one turbine nozzle segment comprises at least one vane extending between an inner band and an outer band;   a design fuel from a fuel source;   at least one fuel injection orifice defined in a surface of the at least one vane, said at least one fuel injection orifice designed to optimize turbine performance using said design fuel;   a non-design fuel channeled through the at least one fuel injection orifice into a compressed fluid flow to establish a jet penetration height; and   an operating window to facilitate reducing the jet penetration height and to facilitate increasing the flame-holding margins.   
   
   
       10 . A system in accordance with  claim 9  wherein said operating window is established by adjusting an operating parameter of said non-design fuel. 
   
   
       11 . A system in accordance with  claim 9  wherein said operating window is defined by adjusting a density of said non-design fuel by changing a temperature of said non-design fuel. 
   
   
       12 . A system in accordance with  claim 11  wherein the temperature is reduced to adjust a non-design fuel momentum ratio. 
   
   
       13 . A system in accordance with  claim 9  wherein said operating window is defined by adjusting a fuel nozzle pressure ratio range by changing a pressure of said non-design fuel. 
   
   
       14 . A system in accordance with  claim 9  wherein said non-design fuel has a modified wobbe index lower than a modified wobbe index of the design fuel. 
   
   
       15 . A method in accordance with  claim 9  wherein said non-design fuel is heated and has a higher modified wobbe index than the design fuel. 
   
   
       16 . A method in accordance with  claim 9  wherein said non-design fuel is at least one of liquefied natural gas, syngas and process gas. 
   
   
       17 . A turbine engine comprising a nozzle assembly comprising an inner band, an outer band, and at least one vane extending between said inner band and said outer band, said vane comprising a plurality of fuel injection orifices designed to optimize performance using a design fuel and configured to channel a non-design fuel therefrom to facilitate controlling flame-holding margins. 
   
   
       18 . A turbine engine in accordance with  claim 17  wherein said inner band comprises at least one fuel supply passage configured to supply said non-design fuel to at least one of said plurality of fuel injection orifices. 
   
   
       19 . A turbine engine in accordance with  claim 17  wherein said non-design fuel is at least one of liquefied naural gas, syngas and process gas. 
   
   
       20 . A turbine engine in accordance with  claim 17  wherein said non-design fuel is cooled to reduce a jet penetration height and a flame-holding region.