U.S. patent application number 12/900668 was filed with the patent office on 2012-04-12 for system and method for determining a flame condition in a combustor.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Douglas Scott Byrd, Joseph Robert Law.
Application Number | 20120088197 12/900668 |
Document ID | / |
Family ID | 45872508 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120088197 |
Kind Code |
A1 |
Byrd; Douglas Scott ; et
al. |
April 12, 2012 |
SYSTEM AND METHOD FOR DETERMINING A FLAME CONDITION IN A
COMBUSTOR
Abstract
A system for determining a flame condition in a combustor
includes a pressure sensor that generates a pressure signal
reflective of a pressure in the combustor. A controller receives
the pressure signal and generates a flame signal reflective of the
flame condition in the combustor. A method for determining a flame
condition in a combustor includes measuring a pressure in the
combustor, comparing the measured pressure in the combustor to a
predetermined limit, and generating a flame signal based on the
comparison of the measured pressure in the combustor to the
predetermined limit, wherein the flame signal reflects the flame
condition in the combustor.
Inventors: |
Byrd; Douglas Scott;
(Greenville, SC) ; Law; Joseph Robert; (Greer,
SC) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
45872508 |
Appl. No.: |
12/900668 |
Filed: |
October 8, 2010 |
Current U.S.
Class: |
431/2 |
Current CPC
Class: |
F23N 5/242 20130101;
F02C 9/50 20130101; F23N 2229/00 20200101; F05D 2260/80 20130101;
F23N 5/16 20130101; F05D 2270/301 20130101; F23N 2241/20 20200101;
F05D 2270/083 20130101; F02C 9/28 20130101; F23N 2231/06
20200101 |
Class at
Publication: |
431/2 |
International
Class: |
F23C 99/00 20060101
F23C099/00 |
Claims
1. A system for determining a flame condition in a combustor
comprising: a. a pressure sensor, wherein said pressure sensor
generates a pressure signal reflective of a pressure in the
combustor; b. a controller, wherein said controller receives said
pressure signal from said pressure sensor and generates a flame
signal reflective of the flame condition in the combustor.
2. The system as in claim 1, wherein said controller compares said
pressure signal to a predetermined limit.
3. The system as in claim 2, wherein said predetermined limit
comprises a predetermined pressure.
4. The system as in claim 1, wherein said pressure sensor generates
a plurality of pressure signals to said controller, wherein each of
said plurality of pressure signals reflects the pressure in the
combustor at a different time.
5. The system as in claim 4, wherein said controller receives said
plurality of pressure signals from said pressure sensor and
generates said flame signal reflective of the flame condition in
the combustor.
6. The system as in claim 4, wherein said controller compares said
plurality of pressure signals to a predetermined profile.
7. The system as in claim 6, wherein said predetermined profile
comprises a predetermined pressure profile.
8. The system as in claim 1, further comprising an igniter that
receives said flame signal.
9. A system for determining a flame condition in a combustor
comprising: a. a pressure sensor, wherein said pressure sensor
generates a series of time indexed pressure signals reflective of
pressures in the combustor at different times; b. a controller,
wherein said controller receives said time indexed pressure signals
from said pressure sensor and generates a flame signal reflective
of the flame condition in the combustor.
10. The system as in claim 9, wherein said controller compares said
time indexed pressure signals to a predetermined profile.
11. The system as in claim 10, wherein said predetermined profile
comprises a predetermined pressure profile.
12. The system as in claim 9, further comprising an igniter that
receives said flame signal.
13. A method for determining a flame condition in a combustor
comprising: a. measuring a pressure in the combustor; b. comparing
the measured pressure in the combustor to a predetermined limit; c.
generating a flame signal based on the comparison of the measured
pressure in the combustor to the predetermined limit, wherein the
flame signal reflects the flame condition in the combustor.
14. The method as in claim 13, further comprising transmitting the
flame signal to an igniter.
15. The method as in claim 13, further comprising transmitting the
flame signal to a compressor.
16. The method as in claim 13, further comprising transmitting the
flame signal to a fuel system.
17. The method as in claim 13, further comprising transmitting the
flame signal to a generator.
18. The method as in claim 13, further comprising measuring a
plurality of pressures in the combustor at different times.
19. The method as in claim 18, further comprising generating the
flame signal based on the plurality of measured pressures in the
combustor, wherein the flame signal is reflective of the flame
condition in the combustor.
20. The method as in claim 18, further comprising comparing the
plurality of pressures to a predetermined profile.
Description
FIELD OF THE INVENTION
[0001] The present invention generally involves a system and method
for determining a flame condition in a combustor. Specifically,
particular embodiments of the present invention monitor pressure in
the combustor to determine the presence and/or absence of a flame
in the combustor.
BACKGROUND OF THE INVENTION
[0002] Combustors are known in the art for igniting fuel with air
to produce combustion gases having high temperature and pressure.
For example, gas turbine systems typically include multiple
combustors that mix a compressed working fluid from a compressor
with fuel and ignite the mixture to produce high temperature and
pressure combustion gases. During initial light-off of a combustor,
it is generally desirable to create and maintain a stable flame in
the combustor immediately prior to or shortly after introducing
fuel into the combustor to initiate and maintain combustion in the
combustor. During steady-state and transient operations, the
fuel-air mixture is constantly being adjusted to optimize
thermodynamic efficiency and reduce undesirable emissions of
nitrous oxide, carbon monoxide, and other combustion byproduct
gases. The adjustments to the fuel-air mixture may create
instabilities in the flame that may lead to a blowout or loss of
flame condition in the combustor, thus interrupting continuity of
the combustion process. In either instance, it is desirable to
detect and monitor the flame condition in the combustor to ensure
safe and continuous operation of the combustor.
[0003] Various systems are known in the art for detecting and/or
monitoring the flame condition in the combustor. For example,
optical sensors that detect light, ultraviolet, or other emissions
produced by a combustion flame may be used to determine the flame
condition in the combustor. Optical sensors, however, typically
require some form of cooling which has a tendency to interfere with
the efficiency and operation of the combustor and/or downstream
components. Temperature detectors in or downstream of the combustor
may also be used to detect and monitor the flame condition in the
combustor. However, the response time of temperature detectors is
typically too slow to provide a timely response to sudden changes
in the flame condition in the combustor. As a result, an improved
system and method for determining the flame condition in a
combustor would be useful.
BRIEF DESCRIPTION OF THE INVENTION
[0004] 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.
[0005] One embodiment of the present invention is a system for
determining a flame condition in a combustor. The system includes a
pressure sensor that generates a pressure signal reflective of a
pressure in the combustor. A controller receives the pressure
signal from the pressure sensor and generates a flame signal
reflective of the flame condition in the combustor.
[0006] Another embodiment of the present invention is a system for
determining a flame condition in a combustor. The system includes a
pressure sensor that generates a series of time indexed pressure
signals reflective of pressures in the combustor at different
times. A controller receives the time indexed pressure signals from
the pressure sensor and generates a flame signal reflective of the
flame condition in the combustor.
[0007] Embodiments of the present invention may also provide a
method for determining a flame condition in a combustor. The method
includes measuring a pressure in the combustor, comparing the
measured pressure in the combustor to a predetermined limit, and
generating a flame signal based on the comparison of the measured
pressure in the combustor to the predetermined limit, wherein the
flame signal reflects the flame condition in the combustor.
[0008] 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
[0009] 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:
[0010] FIG. 1 is a simplified block diagram of a system according
to one embodiment of the present invention;
[0011] FIG. 2 is a block diagram of an algorithm according to one
embodiment of the present invention;
[0012] FIG. 3 is an exemplary graph of pressure in each of 14
different combustors;
[0013] FIG. 4 is a block diagram of an algorithm according to an
alternate embodiment of the present invention; and
[0014] FIG. 5 is an exemplary time-pressure graph for a
combustor.
DETAILED DESCRIPTION OF THE INVENTION
[0015] 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.
[0016] 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.
[0017] Various embodiments of the present invention provide a
system and method for determining a flame condition in a combustor.
As used herein, the "flame condition" is defined to mean the
presence, absence, and/or stability of a flame in the combustor.
Specifically, embodiments of the present invention may sense and
measure pressure, pressure changes, and/or the rate of pressure
changes in the combustor to determine the flame condition in the
combustor. As a result, embodiments of the present invention may
provide a redundant, reliable, and/or replacement system and method
for monitoring the flame condition in a combustor to improve the
overall reliability and performance of the combustor. Although
exemplary embodiments of the present invention are discussed in the
context of a combustor incorporated in a gas turbine system, one of
ordinary skill in the art will readily appreciate that the
teachings of the present invention may be applicable to any system
or method that involves the combustion of fuel, and the scope of
the present invention is not limited to any particular combustor
application unless specifically recited in the claims.
[0018] FIG. 1 provides a simplified block diagram of a system 10 in
the context of a gas turbine system 12 according to one embodiment
of the present invention. As is known in the art, the gas turbine
system 12 generally includes an axial compressor 14 at the front,
one or more combustors 16 around the middle, and a turbine 18 at
the rear. Ambient air 20 enters the compressor 14, and rotating
blades and stationary vanes in the compressor 14 progressively
impart kinetic energy to the air to produce a compressed working
fluid 22 at a highly energized state. As shown in FIG. 1, the
compressor 14 may include an inlet guide vane 24 that may be
adjustable to control or regulate the amount of ambient air 20 that
enters the compressor 14, thus controlling the mass flow rate
and/or pressure of the compressed working fluid 22 exiting the
compressor 14. The compressed working fluid 22 exits the compressor
14 and flows into the combustors 16 where it mixes with fuel
supplied by a fuel system 26. The mixture ignites to generate
combustion gases 28 having a high temperature and pressure. The
combustion gases 28 expand in the turbine 18 to produce work. For
example, expansion of the combustion gases 28 in the turbine 18 may
rotate a shaft 30 connected to a generator 32 to produce
electricity.
[0019] In the embodiment shown in FIG. 1, the system 10 generally
includes a pressure sensor 34 and a controller 36 operatively
connected to the gas turbine system 12 to determine the flame
condition in one or more combustors 16. The pressure sensor 34 may
comprise any suitable instrument known in the art for detecting and
measuring pressure in the combustor 16 and generating one or more
pressure signals 38 reflective of the pressure in the combustor 16.
The controller 36 receives the one or more pressure signals 38 from
each pressure sensor 34 and generates a flame signal 40 reflective
of the flame condition in each combustor 16.
[0020] The controller 36 may be a stand alone component or a
sub-component included in any computer system known in the art,
such as a laptop, a personal computer, a mini computer, a mainframe
computer, or industrial controllers, microcontrollers, or embedded
systems. The various controller and computer systems discussed
herein are not limited to any particular hardware architecture or
configuration. Embodiments of the systems and methods set forth
herein may be implemented by one or more general-purpose or
customized controllers adapted in any suitable manner to provide
the desired functionality. The controller 36 may be adapted to
provide additional functionality, either complementary or unrelated
to the present subject matter. For instance, one or more
controllers may be adapted to provide the described functionality
by accessing software instructions rendered in a computer-readable
form. When software is used, any suitable programming, scripting,
or other type of language or combinations of languages may be used
to implement the teachings contained herein. However, software need
not be used exclusively, or at all. For example, as will be
understood by those of ordinary skill in the art without required
additional detailed discussion, some systems and methods set the
forth and disclosed herein may also be implemented by hard-wired
logic or other circuitry, including, but not limited to,
application-specific circuits. Of course, various combinations of
computer-executed software and hard-wired logic or other circuitry
may be suitable as well.
[0021] The pressure sensor 34 and the controller 36 may operate
intermittently, continuously, and/or when directed by an operator.
For example, FIG. 2 provides a block diagram of an algorithm that
may be programmed, hardwired, or otherwise implemented by the
controller 36 to determine the flame condition in the combustor 16.
Block 50 represents the activation of the flame detection system
10. The activation may be manually or automatically directed. For
example, during an initial combustor 16 light-off, an operator may
manually activate the flame detection system 10 to assist in
determining when ignition occurs in the combustor 16. Alternately,
following a blowout or loss of flame condition in a combustor 16, a
protective or corrective system may automatically activate the
flame detection system 10 to monitor the relight of the flame in
the combustor 16.
[0022] At block 52, the system 10 may energize an igniter 54
operatively connected to the combustor 16 to provide a spark, pilot
light, laser beam, or other ignition source for the combustor 16.
In addition, at block 52 the pressure sensor 34 begins measuring
the pressure in the combustor 16 and generating one or more
pressure signals 38 to the controller 36.
[0023] At block 56, the controller 36 compares the one or more
pressure signals 38 to a predetermined limit to determine the flame
condition in the combustor 16. The predetermined limit provides an
indication of the presence or absence of a flame in the combustor
16 and may be established by calculations, operational experience,
modeling, or other methods known in the art. For example, although
the instantaneous pressure in each combustor 16 may vary
substantially over relatively short time intervals, an
instantaneous pressure in any combustor 16 may be reliably used to
indicate the presence or absence of a flame in an individual
combustor 16. To illustrate this, FIG. 3 shows an exemplary graph
of the instantaneous pressure in each of 14 different combustors 16
in the gas turbine system 12. As shown in FIG. 3, the instantaneous
pressure in combustor number 11 is significantly below the
instantaneous pressure in any other combustor, thus indicating a
loss or lack of flame in combustor number 11. One of ordinary skill
in the art will readily appreciate that the predetermined limit is
not necessarily limited to instantaneous pressure. For example, the
predetermined limit in alternate embodiments may be a change in
pressure, a rate of change in pressure, and/or another calculation
or derivative of pressure in the combustor 16 that indicates the
presence or absence of a flame in the combustor 16.
[0024] The controller 36 generates the flame signal 40 reflective
of the flame condition in the combustor 16 based on the comparison
between the one or more pressure signals 38 and the predetermined
limit. For example, if the comparison between the one or more
pressure signals 38 and the predetermined limit indicates the
presence of a flame in the combustor 16, then the controller 36 may
send the flame signal 40 to the igniter 54 to de-energize the
igniter 54 and/or de-activate the flame detection system 10, as
represented by block 58. Alternately, if the comparison between the
one or more pressure signals 38 and the predetermined limit
indicates the absence of a flame in the combustor 16, then the
flame signal 40 may cause the igniter 54 to remain energized.
[0025] As shown by block 60 in FIG. 2, the algorithm may further
include a predetermined time limit. For example, if the comparison
between the one or more pressure signals 38 indicates the absence
of a flame in the combustor 16, and the predetermined time limit is
not exceeded, the flame signal 40 may cause the igniter 54 to
remain energized. However, if the predetermined time limit is
exceeded, indicating an inability to ignite the combustor 16 within
the predetermined time period, the controller 36 may generate a
signal to de-energize the igniter 54 and/or the flame detection
system 10 and/or increase or decrease the fuel flow to the
combustor 16, as represented by block 58.
[0026] FIG. 4 provides a block diagram of another example of an
algorithm that may be programmed, hardwired, or otherwise
implemented by the controller 36 to determine the flame condition
in the combustor 16 and/or respond to an anticipated change in the
flame condition. Block 70 represents the activation of the flame
detection system 10. As with the embodiment previously described
and illustrated with respect to FIG. 2, the activation may be
manually or automatically directed. For example, an operator may
manually activate the flame detection system 10 during transient
operations to more closely monitor the flame condition to avoid an
inadvertent blowout or loss of flame in the combustor 16.
Alternately, a protective or corrective system may automatically
activate the flame detection system 10 during transient operations
to more closely monitor the flame condition.
[0027] At block 72, the pressure sensor 34 again begins measuring
the pressure in the combustor 16 and generating one or more
pressure signals 38 to the controller 36. In this particular
embodiment, the pressure signals 38 may be time indexed to provide
a continuous stream of pressure signals reflective of pressures in
the combustor 16 at different times. Depending on the particular
embodiment, the system 10 may also energize the igniter 54
operatively connected to the combustor 16 to provide a spark, pilot
light, laser beam, or other ignition source for the combustor
16.
[0028] At block 74, the controller 36 compares the one or more
pressure signals 38 to a predetermined profile, such as a profile
of pressure over a time interval, to determine the flame condition
in the combustor 16. The predetermined profile provides an
indication of the presence or absence of conditions that may lead
to or reliably serve as a precursor to a blowout or loss of flame
condition in the combustor 16 during transient operations. The
predetermined profile may be developed by calculations, operational
experience, modeling, or other methods known in the art. For
example, individual combustors may exhibit distinctive, repeatable,
and observable changes in pressure over a time interval that may be
used to predict or anticipate a blowout or loss of flame condition
in the combustor. To illustrate this, FIG. 5 shows an exemplary
pressure profile 76 of a combustor during a blowout condition 78
and a subsequent re-light 80 of the combustor. As shown in FIG. 5,
the pressure profile 76 illustrates a distinctive pressure, change
in pressure, and/or rate of change in pressure in the combustor 16
during the blowout condition 78 and the subsequent re-light 80 of
the combustor. The controller 36 may thus compare the time indexed
pressure signals 38 to this predetermined profile to generate the
flame signal 40 reflective of the flame condition in the combustor
16. One of ordinary skill in the art will readily appreciate that
the predetermined profile is not necessarily limited to a single
calculation or derivative of pressure in the combustor 16, and the
predetermined profile may comprise a combination of multiple
calculations or derivatives of pressure in the combustor 16. For a
example, the predetermined profile in alternate embodiments may be
a combination of individual profiles of time indexed pressures,
time indexed changes in pressures, time indexed rates of change in
pressures, and/or other calculations or derivatives of pressure in
the combustor 16 that may be reliably used as precursors to a
blowout or loss of flame condition in the combustor 16.
[0029] Returning to FIG. 4, block 82 represents that the system 10
may further use the flame signal 40 to adjust various parameters in
the gas turbine system 12 to avoid a blowout or loss of flame
condition in the combustor 16. For example, as previously described
with respect to the embodiment shown in FIGS. 1 and 2, the igniter
54 may receive the flame signal 40 to energize the igniter 54 and
provide an immediate ignition source for relighting the flame in
the combustor 16. Alternately, or in addition, the controller 36
may transmit the flame signal 40 to the compressor 14 to change the
position of the inlet guide vane 24, to the fuel system 26 to
change the amount of fuel supplied to the combustor 16, and/or to
the generator 32 to change the load on the turbine 18. The system
10 may take each of these actions individually or in combination in
response to the flame signal 40 to stabilize the flame in the
combustor 16 during transient operations that may otherwise result
in a blowout or loss of flame condition in the combustor 16.
[0030] It is anticipated that embodiments of the present invention
provide several benefits over existing technology. For example, the
system 10 and methods described with respect to FIGS. 1-5 may be
used to supplement and/or replace existing optical and thermal
sensors used to determine the flame condition in a combustor. In
addition, embodiments of the present invention may be used to
detect conditions or precursors that may lead to instability in the
flame condition, and in particular embodiments, the system 10 may
take appropriate action to remove or correct the conditions or
precursors to ensure continuity in the combustion process.
[0031] 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.
* * * * *