Abstract: The primary nozzles of a Dry Low NOx (DLN) combustor are configured to alternatively burn a first gas fuel or a second gas fuel, where the two gas fuels may have widely disparate energy content. Natural gas may be the first gas fuel and syngas may be the second gas fuel. An inner fuel circuit and an outer fuel circuit are provided to allow effective control of fuel/air mixing profiles, dynamics, primary pre-ignition and emission control by changing the fuel split between the two fuel circuits. The inner fuel circuit may be run in a diffusion combustion mode on many gas fuels.

Abstract: A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of slots formed in the burner tube and configured to introduce air flows tangentially into the burner tube and impart swirl to the air flows; a plurality of fuel passages extending axially along the burner tube; and a plurality of fuel injection holes provided to each fuel passage. At least one of the fuel injection holes of each fuel passage is configured to inject a fuel flow tangentially into the burner tube between air flows of adjacent slots to form a fuel and air co-flow. A method of mixing air and fuel in a burner of a gas turbine is provided. The burner includes a burner tube including a plurality of slots formed in the burner tube. The method includes introducing air flows tangentially into the burner tube through the slots and imparting swirl to the air flows; and injecting fuel between air flows of adjacent slots to form fuel and air co-flows.