Combustor fuel injection system

摘要

In order to achieve ignition at altitude, particularly in relatively small combustors (10) with low fuel flow rates, a fuel injection system (20) includes an air nozzle (26), a fuel nozzle (28), and an air assist tube (34). The fuel nozzle (28) is disposed in a manner so as to direct fuel through the air nozzle (26) and includes a fuel metering orifice (30) or capillary tube (32) to control fuel flow therethrough. The air assist tube (34) is integrally associated with the fuel nozzle (28) downstream of the fuel metering orifice (30) or capillary tube (32) to accelerate fuel flowing through the fuel nozzle (28). With this arrangement, the air nozzle (26) may comprise an opening in a combustor wall (14) defining a combustion chamber (12) of a turbine engine combustor (10) wherein a combustor case (16) surrounds the combustor wall (14) to define an air flow path 18 in communication with a compressed air source whereby compressed air flows through the opening (26) and into the combustor (10) along with fuel from the fuel nozzle (28) and air from the air assist tube (34).