Abstract: Fuel injection for hydrogen-gas fuels poses risks with regard to emissions, flashback, and flame-holding events in a gas turbine engine. Accordingly, embodiments of a fuel injection system are disclosed that uniformly mix gas and fuel, while stabilizing a flame and facilitating maintenance. The fuel injection system may comprise a plurality of micromixer panels, mounted in windows of a frame that are arranged circumferentially around a longitudinal axis of the gas turbine engine. Each micromixer panel may comprise a plurality of axial channels, arranged around a central pilot body that is fixed in a grommet. Two or more internal fuel feeds may supply fuel to distinct subsets of fuel jets within the outlets of the axial channels, such that the fuel injection system may be operated in multiple stages.

Abstract: In a fuel injector, the temperature differential between a distributor plate, through which relatively cool fuel passes, and the manifold to which the distributor plate is bonded causes stresses and strains that can reduce the durability and longevity of the fuel injector. In disclosed embodiments, the distributor plate is bonded to an outer arm and inner arm. These arms act as levers to take up the stresses and strains caused by the temperature differential, thereby increasing the durability and longevity of the fuel injector.

Abstract: No known single-stage dry low emissions fuel injectors are capable of effectively operating over all ranges of hydrogen concentrations in hydrogen/natural gas fuel mixtures. Accordingly, a fuel injector is disclosed that is capable of operating in both a premix mode for fuel mixtures with lower hydrogen concentrations and a micromix mode for fuel mixtures with higher hydrogen concentrations. The fuel injector may comprise premix jets near an inlet of the fuel injector, optionally within one or more swirlers, and micromix jets near the outlet of the fuel injector. In the premix mode, fuel with lower hydrogen concentrations is provided to the premix jets, whereas in the micromix mode, fuel with higher hydrogen concentrations is provided to the micromix jets.