Patent ID: 6986254
Filing Date: 2006-01-17
Classification: F23R

Abstract:
1. A method of operating a combustion system of a gas turbine engine, said method comprising: a) providing a combustion system wherein having a plurality of first injectors arranged in a first array about a center axis, a plurality of second injectors arranged in a second array radially outward of said first injectors proximate a first swirler to mix fuel with a first portion of compressed air, an aft injector assembly comprising a manifold having at least one injection sector and a plurality of third injectors located in said manifold such that fuel mixes with a second portion of compressed air; b) at ignition, supplying fuel to said first injectors and a first sector of said aft injector assembly with fuel gradually increasing to said first injectors until crossfire is achieved; c) after crossfire has occurred, gradually decreasing fuel flow to said first injectors and decreasing and terminating fuel flow to said first sector of said aft injector assembly and initiating and increasing fuel flow to said second injectors until the engine reaches a full-speed no-load condition; d) at engine full-speed no-load condition, fuel flow gradually increases to said first and second injectors to a first part-load; e) at said first part-load condition, gradually decreasing fuel flow to said first and second injectors while gradually increasing fuel flow to said first sector of said aft injector assembly; f) as load increases, gradually increasing fuel flow to each of said first and second injectors and said first sector of said aft injector assembly to a second part-load condition; g) at said second part-load condition, gradually decreasing fuel flow to said first and second injectors and said first sector of said aft injector assembly, while initiating, and gradually increasing fuel flow to a second sector of said aft injector assembly; and, h) as load increases, gradually increasing fuel flow to said first and second injectors and said first and second sectors of said aft injector assembly.