Bluff body premixing fuel injector and method for premixing fuel and air

摘要

A tangential entry premixing fuel injector (10) for a gas turbine engine combustor includes a pair of offset scrolls (18) whose ends define a pair of entry slots (36) for admitting primary combustion air tangentially into a mixing chamber (28) bounded by the scrolls (18) and by longitudinally spaced endplates (14,16). An array of fuel injection passages (42) extends along the length of the slots. The passage array is configured to inject a primary fuel nonuniformly along the length of the air entry slots and to control the fuel penetration depth d in proportion to slot height H. The injector also includes a flame disgorging centerbody (48) having a bluff tip (54) longitudinally aligned with the injector's discharge plane (22) and a secondary fuel conduit (80) extending through the centerbody for discharging a secondary combustible fluid, preferably gaseous fuel, through a series of fuel discharge openings (84) in the tip (54). The flame disgorging centerbody improves fuel injector durability by resisting ingestion of combustion flame into the mixing chamber (28) and reliably disgorging any flame that is ingested. <IMAGE>