U.S. patent application number 09/940765 was filed with the patent office on 2002-01-10 for apparatus for fuel nozzle staging for gas turbine engines.
Invention is credited to Badeer, Gilbert H..
Application Number | 20020002818 09/940765 |
Document ID | / |
Family ID | 23723839 |
Filed Date | 2002-01-10 |
United States Patent
Application |
20020002818 |
Kind Code |
A1 |
Badeer, Gilbert H. |
January 10, 2002 |
Apparatus for fuel nozzle staging for gas turbine engines
Abstract
A fuel delivery system for fuel nozzle staging includes a gas
circuit and a fuel circuit. Each circuit includes a first manifold
and a second manifold. The fuel delivery system delivers a first
gas and a first fuel to a gas turbine engine during initial
operation through the first manifold connected within each
respective gas circuit. As the gas turbine engine reaches a
predetermined operational speed, staging valves permit the fuel
delivery system to also deliver the first gas and the first fuel to
the gas turbine engine through the second manifold of each
respective gas circuit.
Inventors: |
Badeer, Gilbert H.;
(Loveland, OH) |
Correspondence
Address: |
John S. Beulick
Armstrong Teasdale LLP
Suite 2600
One Metropolitan Sq.
St. Louis
MO
63102
US
|
Family ID: |
23723839 |
Appl. No.: |
09/940765 |
Filed: |
August 28, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09940765 |
Aug 28, 2001 |
|
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|
09434343 |
Nov 5, 1999 |
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Current U.S.
Class: |
60/778 ;
60/734 |
Current CPC
Class: |
F23K 5/005 20130101;
F23L 2900/07009 20130101; F02C 7/228 20130101; F23R 3/34
20130101 |
Class at
Publication: |
60/39.06 ;
60/734 |
International
Class: |
F02C 007/22 |
Claims
What is claimed is:
1. A method for delivering fuel in a gas turbine engine using a
fuel delivery system including at least a first manifold, a second
manifold, and a fuel nozzle sub-system, the first manifold
configured to deliver to the gas turbine engine a first gas during
initial operation of the gas turbine engine, the second manifold
configured to deliver to the gas turbine engine a first fuel during
initial operation of the gas turbine engine, the fuel nozzle
sub-system is connected to the manifolds and includes a plurality
of primary fuel nozzles and a plurality of secondary fuel nozzles,
the primary fuel nozzles configured to receive the first gas and
the first fuel during initial operation of the gas turbine engine,
said method comprising the steps of: supplying the first gas and
the first fuel to the fuel delivery system; and directing the first
gas and the first fuel through the first manifold, the second
manifold, and the fuel nozzle sub-system.
2. A method in accordance with claim 1 wherein the fuel delivery
system further includes a third manifold and a fourth manifold, the
third manifold configured to deliver to the gas turbine engine the
first gas once the gas turbine engine has operated at a
predetermined power level, the fourth manifold configured to
deliver to the gas turbine engine the first fuel once the gas
turbine engine has operated at a predetermined power level with a
predetermined load, said method further comprising the steps of:
accelerating the gas turbine engine from an idle speed; and
directing the first gas and the first fuel through the third
manifold and the fourth manifold after the gas turbine engine has
operated at a predetermined power level with a predetermined
load.
3. A method in accordance with claim 2 wherein the fuel delivery
system further includes a plurality of staging valves configured to
control a flow of the first gas and the first fuel to at least one
of the third manifold or the fourth manifold, said step of
directing the first gas and the first fuel through at least one of
the third manifold and the fourth manifold further comprising the
step of controlling the flow of the first gas and the first fuel
with a plurality of staging valves.
4. A method in accordance with claim 3 wherein the secondary
nozzles are configured to receive the first gas and the first fuel
after the gas turbine engine has operated at the predetermined
power level, said step of accelerating the gas turbine engine
comprising the step of directing the first gas and the first fuel
to the secondary nozzles.
5. A method in accordance with claim 4 wherein the plurality of
primary nozzles includes 20 primary nozzles, said step of directing
the first gas and the first fuel through the first manifold, the
second manifold, and the fuel nozzle sub-system comprises the step
of supplying the 20 primary nozzles with the first gas and the
first fuel.
6. A method in accordance with claim 5 wherein the plurality of
secondary nozzles includes 10 secondary nozzles, said step of
accelerating the gas turbine engine from an idle speed further
comprises the step of simultaneously supplying the 20 primary
nozzles and the 10 secondary nozzles with the first gas and the
first fuel.
7. A fuel delivery system for a gas turbine engine, said fuel
delivery system comprising: at least two manifolds comprising a
first manifold and a second manifold, said first manifold
configured to deliver to the gas turbine engine a first gas during
initial operation of the gas turbine engine, said second manifold
configured to deliver to the gas turbine engine a first fuel during
initial operation of the gas turbine engine; and a fuel nozzle
sub-system connected to said manifolds, said fuel nozzle sub-system
comprising a plurality of primary fuel nozzles and a plurality of
secondary fuel nozzles, said primary fuel nozzles configured to
receive the first gas and the first fuel during initial operation
of the gas turbine engine.
8. A fuel delivery system in accordance with claim 7 further
comprising a third manifold configured to deliver the first gas to
the gas turbine engine once the gas turbine engine has operated at
a predetermined power level with a predetermined load.
9. A fuel delivery system in accordance with claim 8 further
comprising a fourth manifold configured to deliver the first fuel
to the gas turbine engine once the gas turbine engine has operated
at the predetermined power level.
10. A fuel delivery system in accordance with claim 9 further
comprising a plurality of staging valves configured to control a
flow of the first gas and a flow of the first fuel.
11. A fuel delivery system in accordance with claim 9 wherein said
secondary fuel nozzles are configured to receive said first gas and
said first fuel after the gas turbine engine has operated at the
predetermined power level.
12. A fuel delivery system in accordance with claim 7 wherein said
plurality of primary fuel nozzles comprises 20 primary fuel
nozzles, said plurality of secondary fuel nozzles comprises 10
secondary fuel nozzles.
13. A fuel delivery system in accordance with claim 10 wherein said
plurality of staging valves comprises a first staging valve and a
second staging valve.
14. A fuel delivery system in accordance with claim 13 wherein said
first staging valve is configured to control a flow of the first
fuel to said fourth manifold.
15. A fuel delivery system in accordance with claim 13 wherein said
second staging valve is configured to control a flow of the first
gas to said third manifold.
16. A fuel delivery system for a gas turbine engine, said fuel
delivery system comprising: a gas circuit configured to deliver a
first gas to the gas turbine engine, said gas circuit comprising a
first manifold and a second manifold, said first manifold
configured to deliver the first gas during initial operation of the
gas turbine engine; and a fuel circuit configured to deliver to a
first fuel to the gas turbine engine, said first fuel circuit
comprising a first manifold and a second manifold, said first
manifold configured to deliver the first fuel during initial
operation of the gas turbine engine.
17. A fuel delivery system in accordance with claim 16 wherein said
gas circuit further comprises a plurality of nozzles connected to
said gas circuit first manifold and said gas circuit second
manifold, and a staging valve connected to said gas circuit second
manifold, said gas circuit second manifold configured to deliver
the first gas to the gas turbine engine once the gas turbine engine
has operated at a predetermined power level with a predetermined
load, said staging valve configured to control a flow of the first
gas to said gas circuit second manifold.
18. A fuel delivery system in accordance with claim 17 wherein said
fuel circuit further comprises a plurality of nozzles connected to
said fuel circuit first manifold and said fuel circuit second
manifold, and a staging valve connected to said fuel circuit second
manifold, said second manifold configured to deliver the first fuel
to the gas turbine engine once the engine has operated the
predetermined power level, said staging valve configured to control
a flow of first fuel to said fuel circuit second manifold.
19. A fuel delivery system in accordance with claim 18 wherein said
gas circuit plurality of nozzles comprises a plurality of primary
nozzles and a plurality of secondary nozzles, said fuel circuit
plurality of nozzles comprises a plurality of primary nozzles and a
plurality of secondary nozzles.
20. A fuel delivery system in accordance with claim 19 wherein said
gas circuit plurality of primary nozzles and said fuel circuit
plurality of primary nozzles comprise 20 primary nozzles, said gas
circuit plurality of secondary nozzles and said fuel circuit of
secondary nozzles comprise 10 secondary nozzles.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to gas turbine engines and,
more particularly, to fuel delivery systems for fuel nozzle staging
for gas turbine engines.
[0002] Controlling a pressure ratio of fuels delivered to a dual
fuel gas turbine engine is critical for the engine's performance.
Typically, dual fuel gas turbine engines exhibit operability
limitations during normal engine starts and during engine low power
operating conditions. For example, undesirable engine flameouts are
prevalent in gas turbine engines supplied with gas and steam
premix, or dual fuel (gas and liquid), and in steam premix turbines
as a result of the low fuel flow rates supplied during start
conditions. Additionally, flameouts may occur at steady state fuel
flow conditions in gas turbine engines when low pressure
differentials develop at the fuel nozzle tips, i.e., single annular
combustor (SAC) fuel configuration.
[0003] To compound the flammability problem, typically the
performance of gas turbine engine fuel delivery systems are
optimized to be within acceptable performance ranges when the gas
turbine engines are operating at maximum fuel flow conditions.
While optimizing a fuel delivery system to perform at maximum fuel
flow conditions enhances the performance of the gas turbine engine
during high fuel flow conditions, it also increases the possibility
of flameouts during low fuel flow conditions. Fuel nozzle pressures
can be raised to alleviate flammability operability regions of the
engine. However, raising the fuel nozzle pressures to improve the
flammability levels at low fuel flow conditions may cause excessive
and damaging pressures at maximum fuel flow conditions, where the
engine operates more frequently. Additionally, optimizing the fuel
delivery systems at low fuel flow conditions may increase carbon
monoxide emission levels generated by the gas turbine engine, thus
creating potential environmental issues.
BRIEF SUMMARY OF THE INVENTION
[0004] In an exemplary embodiment, a fuel delivery system for fuel
nozzle staging is provided for use with a gas turbine engine. The
fuel delivery system includes two circuits. A gas circuit delivers
a first gas to the gas turbine engine, and includes a first
manifold and a second manifold. A steam circuit delivers steam to
the gas turbine engine and includes a first manifold and a second
manifold. Both the gas circuit and the steam circuit are connected
to a plurality of fuel nozzles which include primary fuel nozzles
and secondary fuel nozzles. Additionally, both circuits include a
staging valve to control the flow of each respective gas and steam
into each respective circuit's second manifold.
[0005] During operation, the gas circuit first manifold and the
steam circuit first manifold deliver a first gas and steam
respectively to the gas turbine engine during initial operation and
idle operation of the gas turbine engine. During initial operations
and idle operations, the primary fuel nozzles deliver the first gas
and steam to the gas turbine engine. Once the gas turbine engine
reaches a predetermined operational speed, the staging valves open
and direct the first gas and steam into the secondary fuel nozzles.
As a result of such fuel nozzle staging, the fuel and control
system eliminates more detrimental fuel delivery systems and
provides a user with a fuel delivery system which improves
flammability limits, accurately controls the delivery of gas, and
provides flexibility to the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic illustration of a fuel delivery system
for operating a fuel nozzle staging for a gas turbine engine;
and
[0007] FIG. 2 is a side elevational view of one embodiment of a
dual fuel nozzle that could be used in conjunction with the fuel
delivery system shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0008] FIG. 1 is a schematic illustration of a fuel delivery system
10 for fuel nozzle staging for a gas turbine engine (not shown).
Fuel delivery system 10 includes a steam circuit 12 and a gas
circuit 14 which respectively deliver a first gas, i.e. steam, and
a first fuel, i.e. gas, to the gas turbine engine. Steam circuit 12
and gas circuit 14 are both metered and sized to achieve a pressure
ratio within fuel delivery system 10 appropriate for the gas being
delivered to the gas turbine engine. Steam circuit 12 delivers a
metered steam flow to the gas turbine engine and gas circuit 14
delivers a metered first gas flow to the gas turbine engine.
[0009] Steam circuit 12 includes a connecting line 16 which extends
from a metering valve (not shown) to a first manifold 20. The
metering valve is positioned between a steam supply source (not
shown) and connecting line 16. The operation of a metering valve
for controlling a flow of steam is well known. In one embodiment,
the first gas supply source is a steam supply source. First
manifold 20 is connected to a connecting line 22 which extends from
manifold 20 to a fuel nozzle sub-system 23 and includes a plurality
of fuel nozzles 24. In one embodiment, manifold 20 is a primary
steam manifold. Fuel nozzles 24 are connected to the gas turbine
engine and deliver steam to the gas turbine engine during initial
operation of the engine and while the gas turbine engine is
operating at an idle speed. In one embodiment, fuel nozzles 24 are
primary fuel nozzles and are available from Parker Hannifin, 6035
Parkland Blvd., Cleveland, Ohio.
[0010] A connecting line 30 is connected to connecting line 16
between manifold 20 and the steam circuit metering valve. The steam
circuit metering valve is connected between the steam supply source
and connecting line 16, upstream of a connection 31 with line 30.
Connecting line 30 extends from connecting line 16 to a staging
valve 32. Staging valve 32 controls the flow of steam from
connecting line 16 to a secondary manifold 34. Staging valve 32 is
sized to accommodate a maximum steam flow for secondary manifold 34
for a secondary steam flow being supplied by fuel delivery system
10. In one embodiment, secondary manifold 34 is a secondary steam
manifold. Secondary manifold 34 is connected to a connecting line
36 which extends from secondary manifold 34 to a plurality of fuel
nozzles 38 of fuel sub-system 23. Fuel nozzles 38 are connected to
the gas turbine engine and deliver the secondary steam and
secondary gas flows to the gas turbine engine once the gas turbine
engine has been operating for a predetermined length of time and is
being accelerated from the initial idle speed. In one embodiment,
fuel nozzles 38 are secondary fuel nozzles and are available from
Parker Hannifin, 6035 Parkland Blvd., Cleveland, Ohio.
[0011] Gas circuit 14 includes a connecting line 50 which extends
from a metering valve (not shown) to a first manifold 52. The
metering valve is positioned between a gas supply source (not
shown) and connecting line 50. In one embodiment, the gas supply
source is a natural gas supply source. First manifold 52 is
connected to a connecting line 54 which extends from manifold 52 to
a plurality of fuel nozzles 56 of fuel sub-system 23. In one
embodiment, manifold 52 is a primary gas manifold. Fuel nozzles 56
are connected to the gas turbine engine to deliver the first fuel
to the engine during initial operation of the gas turbine engine
and while the gas turbine engine is operating at an idle speed. In
one embodiment, fuel nozzles 56 are primary fuel nozzles and are
available from Parker Hannifin, 6035 Parkland Blvd., Cleveland,
Ohio.
[0012] A connecting line 60 is connected to connecting line 50
between manifold 52 and the gas circuit metering valve. The gas
circuit metering valve is connected between the gas supply source
and connecting line 50, upstream of a connection 61 with line 60.
Connecting line 60 extends from connecting line 50 to a staging
valve 62. Staging valve 62 controls the flow of the gas from
connecting line 50 to a secondary manifold 66. Staging valve 62 is
sized to accommodate a maximum gas flow for secondary manifold 66
for the second fuel being supplied by fuel delivery system 10. In
one embodiment, secondary manifold 66 is a secondary gas manifold.
Secondary manifold 66 is connected to a connecting line 68 which
extends from manifold 66 to a plurality of fuel nozzles 70 of fuel
sub-system 23. Fuel nozzles 70 are connected to the gas turbine
engine and deliver the gas to the gas turbine engine once the gas
turbine engine has been operating with a predetermined load at a
predetermined power level and is being accelerated from the initial
synchronous idle speed. In one embodiment, fuel nozzles 70 are
secondary fuel nozzles and are available from Parker Hannifin, 6035
Parkland Blvd., Cleveland, Ohio.
[0013] In operation, fuel delivery system 10 is capable of
delivering the steam and gas such that the gas turbine engine is
capable of starting using a metered gas flow. To start the gas
turbine engine, fuel delivery system 10 stages the metered gas
flows between primary nozzles 24 and 56. In one embodiment, fuel
delivery system includes 20 primary nozzles 24 and 56. During the
gas turbine engine start and during low power modes and idle power
modes, the first gas and steam are delivered to the gas turbine
engine through primary manifolds 20 and 52 to primary fuel nozzles
24 and 56 respectively. While the first gas and steam are being
delivered to primary manifolds 20 and 52, staging valves 32 and 62
are closed to prevent the gas and the steam from being delivered to
secondary manifolds 34 and 66. Delivering the first gas and steam
through primary nozzles 24 and 56 during low power conditions and
idle operations of the gas turbine engine enhances a low pressure
ratio of fuel delivery system 10 which improves flammability limits
for the gas turbine engine. Additionally, it has been determined
that fuel and control system 10 may reduce such emission levels up
to four times greater than known non-premix fuel and control
systems.
[0014] In an alternative embodiment, staging valve 32 and staging
valve 62 provide a pilot flow when staging valves 32 and 62 are in
a fully closed position (not shown). The pilot flow provides a
minimum positive gas flow to manifolds 34 and 66 to prevent
potentially damaging combustion gases from back-flowing from the
gas turbine engine into manifolds 34 and 66.
[0015] The gas turbine engine is then accelerated from synchronous
idle operation. Once the engine reaches a predetermined operational
speed, fuel delivery system 10 directs gas flow to secondary
manifolds 34 and 66 by gradually opening steam circuit staging
valve 32 and gas circuit staging valve 62. As staging valves 32 and
62 are opened, the first gas and steam are directed into manifolds
34 and 66 respectively. Simultaneously, the first gas and steam are
still being directed into primary fuel nozzles 24 and 56 through
manifolds 20 and 52 respectively. Shortly thereafter, secondary
steam and gas flows from secondary fuel nozzles 38 and 70
respectively and into the gas turbine engine. In one embodiment,
fuel delivery system includes 10 secondary fuel nozzles 38 and 70.
Simultaneously, the steam and the first gas are still being
directed into primary fuel nozzles 24 and 56 through manifolds 20
and 52 respectively.
[0016] FIG. 2 is a side elevational view of one embodiment of a
dual fuel nozzle 80 that could be used in conjunction with fuel and
control system 10. Fuel nozzle 80 is similar to fuel nozzles 24,
38, 56, and 70 (shown in FIG. 1). In one embodiment, fuel nozzles
24, 38, 56, and 70 are each the same model fuel nozzle and have the
same set of performance flow characteristics at all power
operations. Therefore, the gas turbine engine exit temperature
pattern factors and profiles are retained as the engine is
accelerated and secondary fuel nozzles 38 and 70 deliver the gas
and steam to the gas turbine engine.
[0017] Nozzle 80 includes a first gas inlet 82, a steam inlet 83, a
nozzle body 84, and a nozzle tip 86. Nozzle body 84 has a first end
88 and a second end 90. First fuel inlet 82 is positioned adjacent
first end 88 and nozzle tip 86 is positioned adjacent second end
90. First fuel inlet 82 extends from nozzle body 84 and includes a
coupling 92 which permits a connection to fuel circuit connection
line 68 (shown in FIG. 1) or fuel circuit connection line 54.
(shown in FIG. 1). Additionally, first fuel inlet 82 includes an
elbow block 94 which connects coupling 92 to nozzle body 84. As
first fuel flows through connecting lines 54 and 68 into coupling
92, elbow 94 directs the first fuel flow from coupling 92 towards
nozzle body 84.
[0018] Steam inlet 83 extends from a coupling 98 attached to nozzle
body 84. Coupling 98 connects nozzle 80 to steam circuit connecting
line 22 (shown in FIG. 1) or steam circuit connecting line 36
(shown in FIG. 1). The steam enters steam inlet in a direction 102
which is substantially parallel to a direction 103 in which the
first gas enters gas inlet 82. Once within nozzle body 84, the gas
is mixed with the steam and directed towards nozzle tip 86.
[0019] The above described fuel delivery system for fuel nozzle
staging for a gas turbine engine is cost-effective and reliable.
The system includes a gas circuit and a fuel circuit wherein each
circuit includes a first manifold and a second manifold. The fuel
delivery system delivers a steam and a first fuel to a turbine
engine during initial operation through a plurality of primary fuel
nozzles. Once the engine reaches a predetermined operational speed,
the fuel delivery system also delivers the steam and the first fuel
to the gas turbine engine through a plurality of secondary fuel
nozzles. Accordingly, a fuel delivery system is provided for fuel
nozzle staging for a gas turbine engine which eliminates more
costly fuel delivery systems and provides a user with a reliable,
flexible, and accurate fuel delivery system for a gas turbine
engine.
[0020] While the invention has been described in terms of various
specific embodiments, those skilled in the art will recognize that
the invention can be practiced with modification within the spirit
and scope of the claims.
* * * * *