Fuel supply system for a gas turbine engine
In one aspect, a fuel supply system may include a fuel injector having a primary and a secondary pilot fuel nozzle in fluid communication with a primary and a secondary fuel circuit, respectively, and a main fuel nozzle in fluid communication with a main fuel circuit. The fuel injector may also define a by-pass fuel circuit connected between the primary circuit and the secondary circuit and/or the main circuit. The system may also include a primary fuel manifold configured to be fluidly connected to the primary pilot fuel nozzle via the primary fuel circuit. Moreover, the system may include a by-pass valve provided in operative association with the by-pass fuel circuit. The by-pass valve may be configured to be opened such that a portion of the fuel flowing through the primary circuit from the primary fuel manifold is directed to the secondary circuit and/or the main circuit.
1. A system for supplying fuel to fuel injectors of a combustor of a gas turbine engine, the system comprising:
a fuel injector including a primary pilot fuel nozzle in fluid communication with a primary fuel circuit, a secondary pilot fuel nozzle in fluid communication with a secondary fuel circuit and a main fuel nozzle in fluid communication with a main fuel circuit, each of the primary, secondary and main fuel circuits extending at least partially within the fuel injector, the fuel injector further defining a by-pass fuel circuit fluidly connected between the primary fuel circuit and at least one of the secondary fuel circuit or the main fuel circuit;
a primary fuel manifold configured to be fluidly connected to the primary pilot fuel nozzle via the primary fuel circuit;
a by-pass valve provided in operative association with the by-pass fuel circuit, the by-pass valve being configured to be opened such that a portion of the fuel flowing through the primary fuel circuit from the primary fuel manifold is directed to the at least one of the secondary fuel circuit or the main fuel circuit; and
further comprising an enriched fuel injector and an enriched fuel manifold, the enriched fuel injector including a second primary pilot fuel nozzle in fluid communication with the enriched fuel manifold via a second primary fuel circuit, a second secondary pilot fuel nozzle in fluid communication with a secondary fuel manifold via a second secondary fuel circuit and a second main fuel nozzle in fluid communication with a main fuel manifold via a second main fuel circuit;
wherein the enriched fuel injector further defines a second by-pass circuit fluidly connected between the second primary fuel circuit and at least one of the second secondary fuel circuit or the second main fuel circuit.
2. The system of claim 1 , wherein the by-pass fuel circuit is fluidly connected between the primary fuel circuit and the secondary fuel circuit, the by-pass valve configured to be opened such that the portion of the fuel flowing through the primary fuel circuit is directed to the secondary fuel circuit and is subsequently delivered to the secondary pilot fuel nozzle.
3. The system of claim 1 , wherein the by-pass valve is housed within a valve housing of the fuel injector.
4. The system of claim 1 , wherein operation of the by-pass valve is configured to be actively or passively controlled.
5. The system of claim 4 , wherein the by-pass valve corresponds to an electronic valve configured to be opened upon receipt of a control signal.
6. The system of claim 4 , wherein the by-pass valve corresponds to a pressure-activated valve configured to be opened when a fluid pressure within the primary fuel circuit exceeds a predetermined cracking pressure.
7. A system for supplying fuel to enriched fuel injectors of a combustor of a gas turbine engine, the system comprising:
an enriched fuel injector including a primary pilot fuel nozzle in fluid communication with a primary fuel circuit, a secondary pilot fuel nozzle in fluid communication with a secondary fuel circuit and a main fuel nozzle in fluid communication with a main fuel circuit, each of the primary, secondary and main fuel circuits extending at least partially within the enriched fuel injector, the enriched fuel injector further defining a by-pass fuel circuit fluidly connected between the primary fuel circuit and at least one of the secondary fuel circuit or the main fuel circuit;
an enriched fuel manifold configured to be fluidly connected to the primary pilot fuel nozzle via the primary fuel circuit;
a secondary fuel manifold configured to be fluidly connected to the secondary pilot fuel nozzle via the secondary fuel circuit;
a main fuel manifold configured to be fluidly connected to the main fuel nozzle via the main fuel circuit;
a by-pass valve provided in operative association with the by-pass fuel circuit, the by-pass valve being configured to be opened such that a portion of the fuel flowing through the primary fuel circuit from the enriched fuel manifold is directed to the at least one of the secondary fuel circuit or the main fuel circuit; and
further comprising a standard fuel injector and a standard fuel manifold, the standard fuel injector including a second primary pilot fuel nozzle in fluid communication with the standard fuel manifold via a second primary fuel circuit, a second secondary pilot fuel nozzle in fluid communication with the secondary fuel manifold via a second secondary fuel circuit and a second main fuel nozzle in fluid communication with the main fuel manifold via a second main fuel circuit;
wherein the standard fuel injector further defines a second by-pass fuel circuit fluidly connected between the second primary fuel circuit and at least one of the second secondary fuel circuit or the second main fuel circuit.
8. The system of claim 7 , further comprising a second by-pass valve provided in operative association with the second by-pass fuel circuit, the second by-pass valve being configured to be opened such that a portion of the fuel flowing through the second primary fuel circuit from the standard fuel manifold is directed to the at least one of the second secondary fuel circuit or the second main fuel circuit.
9. A fuel injector for a combustor of a gas turbine engine, the fuel injector comprising:
a primary fuel circuit in fluid communication with a primary pilot fuel nozzle of the fuel injector, the primary fuel circuit including a primary valve provided in operative association therewith for controlling a primary flow of fuel through the primary fuel circuit to the primary pilot fuel nozzle;
a secondary fuel circuit in fluid communication with a secondary pilot fuel nozzle of the fuel injector, the secondary fuel circuit including a secondary valve provided in operative association therewith for controlling a secondary flow of fuel through the secondary fuel circuit to the secondary pilot fuel nozzle;
a main fuel circuit in fluid communication with a main fuel nozzle of the fuel injector, the main fuel circuit including a main valve provided in operative association therewith for controlling a main flow of fuel through the main fuel circuit to the main fuel nozzle;
a by-pass fuel circuit fluidly connected between the primary fuel circuit and at least one of the secondary fuel circuit or the main fuel circuit;
a by-pass valve provided in operative association with the by-pass fuel circuit, the by-pass valve being configured to be opened such that a portion of the primary flow of fuel flowing through the primary fuel circuit is directed to the at least one of the secondary fuel circuit or the main fuel circuit; and
further comprising an enriched fuel injector and an enriched fuel manifold, the enriched fuel injector including a second primary pilot fuel nozzle in fluid communication with the enriched fuel manifold via a second primary fuel circuit, a second secondary pilot fuel nozzle in fluid communication with a secondary fuel manifold via a second secondary fuel circuit and a second main fuel nozzle in fluid communication with a main fuel manifold via a second main fuel circuit;
wherein the enriched fuel injector further defines a second by-pass fuel circuit fluidly connected between the second primary fuel circuit and at least one of the second secondary fuel circuit or the second main fuel circuit.
10. The fuel injector of claim 9 , wherein the by-pass fuel circuit is fluidly connected to the secondary fuel circuit at a location downstream of the secondary valve, the by-pass valve configured to be opened such that the portion of the fuel flowing through the primary fuel circuit is directed to the secondary fuel circuit and is subsequently delivered to the secondary pilot fuel nozzle.
11. The fuel injector of claim 9 , wherein the by-pass valve, the primary valve, the secondary valve and the main valve are housed within a valve housing of the fuel injector.
12. The fuel injector of claim 9 , wherein operation of the by-pass valve is configured to be actively or passively controlled.
13. The fuel injector of claim 12 , wherein the by-pass valve corresponds to a pressure-activated valve configured to be opened when a fluid pressure within the primary fuel circuit exceeds a predetermined cracking pressure.