U.S. patent application number 12/898887 was filed with the patent office on 2012-04-12 for apparatus and method for modifying a combustor nozzle.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Bharat Bagepalli, Donald Timothy Lemon, Elias Marquez, Richard Arthur Symonds.
Application Number | 20120088201 12/898887 |
Document ID | / |
Family ID | 45872507 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120088201 |
Kind Code |
A1 |
Marquez; Elias ; et
al. |
April 12, 2012 |
APPARATUS AND METHOD FOR MODIFYING A COMBUSTOR NOZZLE
Abstract
A combustor nozzle includes a nozzle body that defines a cavity.
An orifice in the nozzle body provides fluid communication from the
cavity through the nozzle body. A movable barrier proximate to the
orifice has a first position in which the movable barrier at least
partially obstructs the orifice. A method for supplying fuel to a
combustor includes flowing fuel through an orifice in a nozzle,
determining a reactivity of the fuel, and adjusting an effective
cross sectional area of the orifice based on the reactivity of the
fuel.
Inventors: |
Marquez; Elias; (Queretaro,
MX) ; Bagepalli; Bharat; (Niskayuna, NY) ;
Symonds; Richard Arthur; (Longwood, FL) ; Lemon;
Donald Timothy; (Greenville, SC) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
45872507 |
Appl. No.: |
12/898887 |
Filed: |
October 6, 2010 |
Current U.S.
Class: |
431/350 |
Current CPC
Class: |
F23R 2900/00016
20130101; F23R 3/28 20130101; F23R 3/14 20130101 |
Class at
Publication: |
431/350 |
International
Class: |
F23D 14/46 20060101
F23D014/46 |
Claims
1. A combustor nozzle comprising: a. a nozzle body, wherein the
nozzle body defines a cavity; b. an orifice in the nozzle body,
wherein the orifice provides fluid communication from the cavity
through the nozzle body; and c. a movable barrier proximate to the
orifice, wherein the movable barrier has a first position in which
the movable barrier at least partially obstructs the orifice.
2. The combustor nozzle as in claim 1, further comprising means for
moving the movable barrier.
3. The combustor nozzle as in claim 1, wherein the movable barrier
is inside the cavity.
4. The combustor nozzle as in claim 1, wherein the movable barrier
reduces an effective cross sectional area of the orifice in the
first position.
5. The combustor nozzle as in claim 1, wherein the movable barrier
has a second position in which the movable barrier increases an
effective cross sectional area of the orifice.
6. The combustor nozzle as in claim 1, further comprising a
plurality of orifices in the nozzle body and a plurality of movable
barriers proximate to the plurality of orifices, wherein the
plurality of movable barriers have a first position that at least
partially obstructs the plurality of orifices.
7. The combustor nozzle as in claim 1, further comprising a hub
inside the cavity, wherein the barrier is connected to the hub.
8. The combustor nozzle as in claim 7, wherein the movable barrier
is in threaded engagement with the hub.
9. A combustor nozzle comprising: a. a nozzle body, wherein the
nozzle body defines a cavity; b. an orifice in the nozzle body,
wherein the orifice provides fluid communication from the cavity
through the nozzle body; and c. a removable insert in the orifice,
wherein the removable insert reduces effective cross sectional area
of the orifice.
10. The combustor nozzle as in claim 9, wherein the removable
insert as in threaded engagement with the orifice.
11. The combustor nozzle as in claim 9, wherein the removable
insert is press fit into the orifice.
12. The combustor nozzle as in claim 9, wherein the removable
insert has a grooved internal surface.
13. The combustor nozzle as in claim 9, wherein the removable
insert has an internal surface and further comprising turbulators
on the internal surface.
14. The combustor nozzle as in claim 9, further comprising a
plurality of orifices in the nozzle body, wherein each of the
plurality of orifices provides fluid communication from the cavity
through the nozzle body.
15. The combustor nozzle as in claim 14, further comprising the
removable insert in each of the plurality of orifices, wherein each
removable insert reduces an effective cross sectional area of the
orifice therein.
16. A method for supplying fuel to a combustor comprising: a.
flowing fuel through an orifice in a nozzle; b. determining a
reactivity of the fuel; c. adjusting an effective cross sectional
area of the orifice based on the reactivity of the fuel.
17. The method as in claim 16, further comprising reducing the
effective cross sectional area of the orifice.
18. The method as in claim 16, further comprising installing an
insert into the orifice.
19. The method as in claim 16, further comprising removing an
insert from the orifice.
20. The method as in claim 16, further comprising flowing fuel
through a plurality of orifices in the nozzle and adjusting an
effective cross sectional area of the plurality of orifices based
on the reactivity of the fuel.
Description
FIELD OF THE INVENTION
[0001] The present invention generally involves an apparatus and
method for modifying a combustor nozzle. In particular, embodiments
of the present invention include a nozzle that can be adjusted to
operate with fuels having different reactivity levels.
BACKGROUND OF THE INVENTION
[0002] Combustors are widely used in commercial operations. For
example, a typical gas turbine includes a compressor that supplies
a compressed working fluid to at least one combustor. The combustor
mixes fuel with the compressed working fluid and ignites the
mixture to produce combustion gases having a high temperature and
pressure. The combustion gases exit the combustor and flow to a
turbine where they expand to produce work.
[0003] Various fuels may be supplied to the combustor for
combustion. For example, the combustor may be designed to operate
using blast furnace gas, coke oven gas, natural gas, vaporized
liquefied natural gas (LNG), propane, hydrogen, or combinations
thereof. Each fuel type generally has a different reactivity for
combustion. In addition, the reactivity may vary among fuels of the
same type, depending on various factors such as the fuel supplier,
purity, temperature, addition of diluents, etc. Changes in the fuel
may change the operation and/or performance of various components
in the gas turbine. For example, a change in the reactivity of the
fuel may change the pressure, temperature, and output of the
combustor. Therefore, it may be desirable to adjust the combustor,
and specifically the nozzles in the combustor, to accommodate fuels
having different reactivity levels.
[0004] Various efforts have been made to design and operate
combustors with different reactivity fuels. For example, the
operating limits of the combustors may be adjusted based on the
reactivity of the fuel. However, this solution may result in
reduced operating limits for the combustors or other equipment
associated with the gas turbine. Another solution for operating
combustors with different reactivity fuels is to shut down the
combustor and replace one or more nozzles with substitute nozzles
having different sized fuel orifices. However, this method requires
interruption of the service provided by the gas turbine as well as
an inventory of substitute nozzles. Interruption of the service
provided by the gas turbine obviously results in unplanned and
unwanted outages, and the inventory of substitute nozzles increases
the operating costs for the gas turbine. As a result, an improved
nozzle that can be adjusted to operate with different reactivity
fuels would be desirable.
BRIEF DESCRIPTION OF THE INVENTION
[0005] Aspects and advantages of the invention are set forth below
in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
[0006] One embodiment of the present invention is a combustor
nozzle that includes a nozzle body that defines a cavity. An
orifice in the nozzle body provides fluid communication from the
cavity through the nozzle body. A movable barrier proximate to the
orifice has a first position in which the movable barrier at least
partially obstructs the orifice.
[0007] Another embodiment of the present invention is a combustor
nozzle that includes a nozzle body that defines a cavity. An
orifice in the nozzle body provides fluid communication from the
cavity through the nozzle body. A removable insert in the orifice
reduces effective cross sectional area of the orifice.
[0008] The present invention also includes a method for supplying
fuel to a combustor. The method includes flowing fuel through an
orifice in a nozzle, determining a reactivity of the fuel, and
adjusting an effective cross sectional area of the orifice based on
the reactivity of the fuel.
[0009] Those of ordinary skill in the art will better appreciate
the features and aspects of such embodiments, and others, upon
review of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A full and enabling disclosure of the present invention,
including the best mode thereof to one skilled in the art, is set
forth more particularly in the remainder of the specification,
including reference to the accompanying figures, in which:
[0011] FIG. 1 is a simplified cross-section of a combustor known in
the art;
[0012] FIG. 2 is a simplified cross-section of a nozzle according
to one embodiment of the present invention;
[0013] FIG. 3 is a simplified cross-section of a nozzle according
to an alternate embodiment of the present invention;
[0014] FIG. 4 is a perspective view of a removable insert according
to one embodiment of the present invention;
[0015] FIG. 5 is a perspective view of a removable insert according
to a second embodiment of the present invention; and
[0016] FIG. 6 is a perspective view of a removable insert according
to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Reference will now be made in detail to present embodiments
of the invention, one or more examples of which are illustrated in
the accompanying drawings. The detailed description uses numerical
and letter designations to refer to features in the drawings. Like
or similar designations in the drawings and description have been
used to refer to like or similar parts of the invention.
[0018] Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that modifications and
variations can be made in the present invention without departing
from the scope or spirit thereof. For instance, features
illustrated or described as part of one embodiment may be used on
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0019] Various embodiments of the present invention provide a
nozzle for a combustor that may be used with different reactivity
fuels. The nozzle generally includes one or more orifices for
flowing fuel into a combustion chamber, and the cross sectional
area of the one or more orifices may be increased or decreased
according to the reactivity of the fuel. As a result, the nozzle
may be adjusted to be used with fuels having different reactivity
levels.
[0020] FIG. 1 provides a simplified cross-section of a combustor 10
within the scope of the present invention. Although the combustor
10 illustrated in FIG. 1 is suitable for use in a gas turbine
system, one of ordinary skill in the art will readily appreciate
that the embodiments of the present invention described herein are
not limited to a combustor used in a gas turbine system, unless
specifically recited in the claims. A casing 12 may surround the
combustor 10 to contain a compressed working fluid. Nozzles may be
arranged in an end cover 16, for example, with primary nozzles 18
radially arranged around a secondary nozzle 20, as shown in FIG. 1.
A liner 22 downstream of the nozzles 18, 20 may define an upstream
chamber 24 and a downstream chamber 26 separated by a throat 28.
The compressed working fluid may flow between the casing 12 and the
liner 22 to the nozzles 18, 20. The nozzles 18, 20 mix fuel with
the compressed working fluid, and the mixture flows from the
nozzles 18, 20 into the upstream 24 and downstream 26 chambers
where combustion occurs.
[0021] FIG. 2 provides a simplified cross-section of a nozzle 30
installed in the end cover 16 of the combustor 10 according to one
embodiment of the present invention. As shown, the nozzle 30
generally includes a nozzle body 32 that defines a cavity 34 inside
the nozzle 30 and one or more orifices 36 in the nozzle body 32
that provide fluid communication from the cavity 34 through the
nozzle body 32. The nozzle 30 may further include a shroud 38
surrounding the nozzle body 32 with one or more swirler vanes 40
radially arranged between the shroud 38 and the nozzle body 32. A
supply of fuel 42 connected to the nozzle 30 supplies fuel to the
cavity 34. The fuel then flows through the one or more orifices 36,
and the swirler vanes 40, if present, swirl the fuel entering the
upstream chamber 24 prior to combustion.
[0022] As shown in FIG. 2, the nozzle may further include one or
more movable barriers 44 proximate to the one or more orifices 36.
The movable barrier 44 generally includes a distal end 46 having
any geometric shape. For example, the distal end 46 may comprise a
cylinder, circle, square, triangle, or other geometric shape. The
movable barrier 44 may be located completely inside the cavity 34,
as shown in FIG. 2. In alternate embodiments, the movable barrier
44 may be located partially inside the cavity 34, with the distal
end 46 extending through the orifice 36.
[0023] The movable barrier 44 has a first position and a second
position. In the first position, the distal end 46 of the movable
barrier 44 is closer to the orifice 36 to obstruct the orifice 36
and/or reduce the effective cross sectional area of the orifice 36.
As used herein, the effective cross sectional area of the orifice
36 is the total area through which the fuel they flow from the
cavity 34 into the upstream chamber 24. For example, in the first
position, the distal end 46 of the movable barrier 44 may be close
enough to the orifice 36, or even inside the orifice 36, so as to
reduce the effective cross sectional area of the orifice 36,
thereby reducing the flow rate of fuel from the cavity 34, through
the orifice 36, and into the combustion chamber 24. In the second
position, the distal end 46 of the movable barrier 44 may be
further from the orifice 36 so as to increase the effective cross
sectional area of the orifice 36. For example, in the second
position, the distal end 46 of the movable barrier 44 may be far
enough from the orifice 36 so that the effective cross sectional
area of the orifice 36 is maximized, thereby increasing the flow
rate of fuel from the cavity 34, through the orifice 36, and into
the combustion chamber 24.
[0024] The movable barrier 44 may be connected to a hub 48 inside
the cavity 34 and may include means for moving the movable barrier
44. For example, as shown in FIG. 2, each distal end 46 may be
connected by a rod 50 or piston to the hub 48. Each rod 50 or
piston may include internal or external threads 52 that provide a
threaded engagement between each rod 50 and the hub 48. In this
manner, the threaded engagement between each rod 50 and the hub 48
provides the means for moving the movable barrier 44. Alternately,
or in addition, the means for moving the movable barrier 44 may
comprise a pneumatic or hydraulic supply 54 connected to the hub
48. Air or another fluid may thus be supplied to the hub 48 to
pneumatically or hydraulically extend or retract each rod 50 with
respect to the hub 48. In still further embodiments, the means for
moving the movable barrier 44 may comprise any articulated,
threaded, ratcheted, hinged, or other mechanical structure known in
the art for reciprocating movement.
[0025] The embodiment of the nozzle 30 shown and described with
respect to FIG. 2 thus provides several advantages over existing
designs. For example, a customer may determine a reactivity of the
fuel and readily adjust the flow rate of fuel through the nozzle 30
by adjusting the position of the movable barrier 44. In this
manner, the customer may adjust the effective cross sectional area
of the orifices 36 in the nozzle 30 based on the reactivity of the
fuel. As a result, the customer does not have to maintain an
inventory of substitute nozzles and may instead switch between fuel
types or different reactivity fuels without requiring an
unscheduled or unwanted shutdown to replace the nozzle. In
addition, the movable barrier 44 allows the customer to slightly
adjust the position of the movable barrier 44 during steady-state
operations to achieve a desired combustor output.
[0026] FIG. 3 shows is a simplified cross-section of a nozzle 60
according to an alternate embodiment of the present invention. As
shown, the nozzle 60 generally includes a nozzle body 62 that
defines a cavity 64 inside the nozzle 60 and one or more orifices
66 in the nozzle body 62 that provide fluid communication from the
cavity 64 through the nozzle body 62. The nozzle 60 may further
include a shroud 68 surrounding the nozzle body 62 with one or more
swirler vanes 70 radially arranged between the shroud 68 and the
nozzle body 62. A supply of fuel 72 connected to the nozzle 60
supplies fuel to the cavity 64. The fuel than flows through the one
or more orifices 66, and the swirler vanes 70, if present, swirl
the fuel entering the combustion chamber 24 prior to
combustion.
[0027] As shown in FIG. 3, the nozzle 60 may further include one or
more removable inserts 74 in one or more orifices 66. The removable
inserts 74 may have various internal diameters corresponding to
various reactivity levels in the fuel. In particular embodiments,
the removable inserts 74 may comprise a solid insert that serves as
a plug to completely block fuel flow through an individual orifice
66. In this manner, the removable inserts 74 may be installed in
each orifice 66 or a subset of orifices 66 to reduce the effective
cross sectional area of the orifices 66, thereby reducing the flow
rate of fuel from the cavity 64, through the orifices 66, and into
the combustion chamber 24. When desired, the removable inserts 74
may be removed from the orifices 66 so that the effective cross
sectional area of the orifices 66 is maximized, thereby increasing
the flow rate of fuel from the cavity 64, through the orifices 66,
and into the combustion chamber 24.
[0028] FIGS. 4, 5, and 6 provide perspective views of removable
inserts according to alternate embodiments of the present
invention. For example, the removable insert 74 shown in FIG. 4
includes a smooth inner surface 76 and a threaded outer surface 78
that allows the removable insert 74 may be threaded into or out of
the orifice 66. The removable insert 80 shown in FIG. 5 includes a
smooth outer surface 82 and a grooved or rifled inner surface 84.
The removable insert 86 shown in FIG. 6 similarly includes a smooth
outer surface 82 with turbulators 88 on the inner surface. In this
manner, the removable inserts 80, 86 shown in FIG. 5 or 6 may be
press fit into the orifice 66, and the grooved inner surface 84 or
turbulators 88 on the inner surface enhances swirling,
acceleration, and/or mixing of fuel flowing through the removable
inserts 80, 86.
[0029] The embodiment of the nozzle 60 shown and described with
respect to FIGS. 3, 4, 5, and 6 thus provides several advantages
over existing designs. For example, a customer may determine a
reactivity of the fuel and readily adjust the flow rate of fuel
through the nozzle 60 by installing or removing one or more
removable inserts 74 from one or more orifices 66. In this manner,
the customer may adjust the effective cross sectional area of the
orifices 66 in the nozzle 60 based on the reactivity of the fuel.
As a result, the customer does not have to maintain an inventory of
substitute nozzles and may instead switch between fuel types or
fuels having different reactivity levels without replacing the
nozzle.
[0030] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other and examples are intended to be within the
scope of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *