CATALYTIC COMBUSTOR HAVING SECONDARY FUEL INJECTION FOR LOW NO.SUB.X STATIONARY COMBUSTION TURBINES

摘要

49,667 A combustion turbine is provided with a plurality of catalytic combustors each of which includes a combustor basket coupled to a transition duct through a catalytic unit such that the parts are free to grow axially with operating temperature changes. The combustor basket is provided with a primary nozzle at its upstream end to provide fuel for conventional combustion and dilution in a primary zone. A plurality of secondary nozzles are provided for fuel injection through the basket sidewall at the downstream end of the primary zone. A fuel preparation zone is provided within the basket from the secondary fuel injection location to the catalytic unit to provide uniform mixing of the fuel in the gas flow. During startup and lower loads, primary fuel is supplied to energize the turbine without secondary fuel. At a predetermined load, secondary fuel flow is initiated and primary fuel is cut back to a level sufficient to provide any preheat needed to raise the secondary fuel mixture to a level required for catalytic activity.