Patent ID: 9003806
Filing Date: 2015-04-14
Classification: F23D,F23N,F23R,Y02E

Abstract:
1. A method of operating a combustor, the combustor having a central nozzle and a plurality of outer nozzles surrounding the central nozzle, comprising; providing a liquid fuel to only the plurality of outer nozzles at a specified total energy input; and transitioning from liquid fuel operation of the combustor to gas fuel operation, the transition comprising: decreasing the liquid fuel to the plurality of outer nozzles while simultaneously increasing a gas fuel to the central nozzle and the plurality of outer nozzles to substantially maintain the specified total energy input; supplying a fuel-air ratio of the gas fuel to the central nozzle that exceeds a threshold value such that a central nozzle flame is anchored; supplying the fuel-air ratio of the gas fuel to the plurality of outer nozzles that is less than the threshold value such that a plurality of outer nozzle flames are lifted; ceasing a supply of the liquid fuel to the plurality of outer ports while substantially maintaining the specified total energy input; and supplying a purge flow to the plurality of outer nozzles.