Patent ID: 6715295
Filing Date: 2004-04-06
Classification: F02C

Abstract:
A gas turbine engine having a dual-mode combustor comprising:a pre-mixed combustion zone disposed downstream of a first fuel delivery element; a diffusion combustion zone disposed downstream of a second fuel delivery element; a water injection apparatus for selectively injecting water into only the diffusion combustion zone and not the pre-mixed combustion zone for controlling combustion temperature in the diffusion flame zone; a fuel system for supplying fuel through said fuel delivery elements to said pre-mixed combustion zone and said diffusion combustion zone, a pilot fuel fraction being a ratio of a fuel flow rate provided to the pilot diffusion combustion zone divided by a sum of the fuel flow rate provided to the pilot diffusion combustion zone plus a fuel flow rate provided to the pre-mixed combustion zone; and a controller operatively connected to the fuel system and comprising logic for increasing the pilot fuel fraction prior to initiating the operation of the water injection apparatus to selectively inject water into only the diffusion combustion zone.