Abstract: A turbomachine combustor portion includes a combustion chamber. A center injection nozzle is arranged within the combustion chamber and includes a center nozzle inlet and a center nozzle outlet. An outer premixed injection nozzle is positioned radially outward of the center injection nozzle and includes an outer nozzle inlet and an outer nozzle outlet that is arranged upstream of the center nozzle outlet. A late lean injector is positioned downstream of the center nozzle and the outer premixed nozzle. The combustor portion includes a first combustion zone arranged downstream of the outer nozzle outlet, a second combustion zone arranged downstream of the center nozzle outlet, and a third combustion zone arranged further downstream of the center nozzle outlet. The center injection nozzle, outer premixed injection nozzle, and late lean injector are selectively operated to establish a combustion flame front in the first, second, and third combustion zones.

Abstract: A turbomachine combustor portion includes a combustion chamber. A center injection nozzle is arranged within the combustion chamber and includes a center nozzle inlet and a center nozzle outlet. An outer premixed injection nozzle is positioned radially outward of the center injection nozzle and includes an outer nozzle inlet and an outer nozzle outlet that is arranged upstream of the center nozzle outlet. A late lean injector is positioned downstream of the center nozzle and the outer premixed nozzle. The combustor portion includes a first combustion zone arranged downstream of the outer nozzle outlet, a second combustion zone arranged downstream of the center nozzle outlet, and a third combustion zone arranged further downstream of the center nozzle outlet. The center injection nozzle, outer premixed injection nozzle, and late lean injector are selectively operated to establish a combustion flame front in the first, second, and third combustion zones.

Abstract: Apparatus for providing electromagnetic radiation to a combustor during a combustion process are disclosed. An electromagnetic radiation source delivers electromagnetic radiation through a first waveguide to a second waveguide that includes an electromagnetic radiation outlet positioned to deliver electromagnetic radiation to the interior of the combustor. Electromagnetic radiation is delivered to low temperature regions of a combustor to reduce carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions. In addition, the electromagnetic radiation stimulates the combustion process so that lean air-fuel mixtures and low BTU gases can be burned at lower combustion temperatures leading to reduced NOx emissions.

Abstract: A combustor for a gas turbine includes a plurality of radially outer nozzles arranged in an annular array, each of the radially outer nozzles having an outlet end located to supply fuel and/or air to a first combustion chamber. A center nozzle has an outlet end located axially upstream of the outlet ends of the radially outer nozzles, and is configured and arranged to supply fuel and air to a second combustion chamber axially upstream of the first combustion chamber. The second combustion chamber opens into the first combustion chamber and has a length sufficient to maintain a center nozzle flame confined to the second combustion chamber.