US 2002/0162333 A1 · Partial premix dual circuit fuel injector

Abstract

A low emission fuel injection system and combustion chamber for use in gas turbine engines comprises one fuel injection body having a dual circuit to supply both pilot and main fuel systems. Both pilot fuel circuit and a main fuel circuit inject fuel at essentially the same axial and radial location. The recessed pilot fuel injection site is along the combustor centerline into a swirling air passage produced by axial air swirlers. The main fuel is injected radially through a plurality of injection sites, at a compound angle, into the inner diameter of a swirling air passage produced by radial air swirlers. The fuel/air residence time prior to entering the combustion chamber is relatively short, minimizing the likelihood of auto ignition. During pilot circuit only operation, the flame is stabilized by a swirler produced recirculation zone, producing high temperatures to completely burn the fuel producing low CO and UHC emissions. During intermediate and high engine power conditions, both the main fuel and pilot circuits discharge fuel into a swirler produced, high air flow, recirculation zone producing a fuel lean, low temperature flame to reduce NOx emissions.

Claims14

Dependent claims

A gas turbine engine fuel injection and combustor system, comprising:

an outer casing extending from an upstream end to a downstream end, an internal space of the downstream end defining a combustion chamber;
an annular dome connected to an internal, upstream end of the outer casing;
a radial flow air swirler mounted to an internal surface of the annular dome and to an external surface of a fuel injector body, said swirler providing swirled air to the combustion chamber;
a fuel injector body mounted to an internal surface of the radial flow air swirler, said fuel injector body comprising a plurality of axially oriented air swirlers, an axially located pilot circuit fuel nozzle, and a plurality of radially oriented main circuit fuel nozzles;
whereby during low power gas turbine engine operation, pilot circuit fuel is mixed with axial swirler produced air flow, and is thereby caused to rotate in a vortex around a longitudinal axis of the combustion chamber and upon ignition produces a stable high temperature emission free flame;
whereby during intermediate and high power gas turbine engine operation, pilot circuit and main circuit fuel is mixed with radial and axial swirler produced air flow, and is thereby caused to rotate in a double vortex around the longitudinal axis of said combustion chamber, and upon ignition produces a stable, fuel lean, low temperature, low pollutant emission flame.

3 more elements

Dependencies are inferred from the claim text.

Partial premix dual circuit fuel injector

Life of this patent

Partial premix dual circuit fuel injector

Life of this patent

Abstract

Claims14