U.S. patent application number 12/609997 was filed with the patent office on 2011-05-05 for valve sequencing system and method for controlling turbomachine acoustic signature.
This patent application is currently assigned to DRESSER-RAND COMPANY. Invention is credited to Stephen Samuel Rashid, Joseph Andrew Tecza.
Application Number | 20110103930 12/609997 |
Document ID | / |
Family ID | 43925627 |
Filed Date | 2011-05-05 |
United States Patent
Application |
20110103930 |
Kind Code |
A1 |
Tecza; Joseph Andrew ; et
al. |
May 5, 2011 |
Valve Sequencing System and Method for Controlling Turbomachine
Acoustic Signature
Abstract
A system and method for controlling the acoustic signature of a
turbomachine having a plurality of valves wherein an operating load
is identified and an arc of admission across a plurality of nozzles
is associated therewith. A valve sequencing scheme is selected and
implemented to activate the arc of admission for a particular
operating load so as to minimize valve noise by adjusting valves
simultaneously rather than consecutively.
Inventors: |
Tecza; Joseph Andrew; (Scio,
NY) ; Rashid; Stephen Samuel; (Wellsville,
NY) |
Assignee: |
DRESSER-RAND COMPANY
Olean
NY
|
Family ID: |
43925627 |
Appl. No.: |
12/609997 |
Filed: |
October 30, 2009 |
Current U.S.
Class: |
415/1 ;
415/13 |
Current CPC
Class: |
F05D 2260/96 20130101;
F01D 17/145 20130101; F05D 2270/331 20130101; F05D 2270/333
20130101; F01D 17/18 20130101; F05D 2270/3061 20130101 |
Class at
Publication: |
415/1 ;
415/13 |
International
Class: |
F01D 25/04 20060101
F01D025/04 |
Claims
1. A method of controlling a turbomachine comprising: identifying
an arc of admission corresponding to a desired operating load,
wherein turbomachine valves are either completely closed or
completely open when the arc of admission is achieved; and changing
a position of at least one of the turbomachine valves using a valve
sequencing scheme to expose the identified arc of admission and
minimize an acoustic signature of the turbomachine valves during
implementation of the desired operating load.
2. The method of claim 1, wherein the valve sequencing scheme is
configured to position one or more turbomachine valves
simultaneously.
3. The method of claim 1, wherein a plurality of arcs of admission
for the desired operating load over a period of time is
identified.
4. The method of claim 3, wherein the valve sequencing scheme
includes simultaneously adjusting the valves in at least two
different combinations over the period of time to achieve each of
the plurality of arcs of admission.
5. The method of claim 1, wherein identifying the arc of admission
includes identifying an arc of admission that reduces the acoustic
signature of the turbomachine valves during implementation of the
desired operating load.
6. The method of claim 1, wherein implementation of the desired
operating load includes controlling a flow rate of a process gas
through the plurality of turbomachine valves.
7-20. (canceled)
21. A method of controlling a turbomachine having valves,
comprising: identifying a first valve sequence that corresponds to
a first operating load of the turbomachine, wherein the first valve
sequence is configured to expose a first arc of admission;
identifying a second valve sequence that corresponds to a second
operating load of the turbomachine, wherein the second valve
sequence is configured to expose a second arc of admission; and
transitioning the valves from the first valve sequence to the
second valve sequence such that the second operating load is
achieved immediately before the second valve sequence is initiated
and each of the valves is either completely closed or completely
open when the second valve sequence is achieved.
22. The method of claim 21, wherein the first and second operating
loads of the turbomachine comprise first and second flow rates of
process gas, respectively, through the valves.
23. The method of claim 21, wherein transitioning the valves from
the first valve sequence to the second valve sequence comprises
opening a first valve and an adjacent second valve simultaneously,
wherein the second valve begins to be opened before the first valve
is completely open.
24. The method of claim 21, further comprising manipulating the
position of the valves simultaneously during transition from the
first valve sequence to the second valve sequence.
25. The method of claim 21, further comprising manipulating a
position of each valve with a corresponding individual valve
actuator.
26. The method of claim 25, wherein the individual valve actuators
are controlled by a control system configured to reduce the
acoustic signature of the valves.
27. The method of claim 26, further comprising using the control
system to regulate the operation of the valves based on
predetermined acoustic requirements of the turbomachine.
28. A turbomachine, comprising: a plurality of valve actuators
coupled to a corresponding plurality of valves; a valve control
system adapted to control the plurality of valve actuators and
implement a valve sequencing scheme by changing the position of the
plurality of valves between a first valve sequence and a second
valve sequence; and a diaphragm in fluid communication with the
plurality of valves, wherein the first valve sequence corresponds
to a first arc of admission exposed across the diaphragm and the
second valve sequence corresponds to a second arc of admission
exposed across the diaphragm, and wherein transitioning from the
first valve sequence to the second valve sequence minimizes an
acoustic signature of the plurality of valves.
29. The turbomachine of claim 28, wherein the valve control system
is configured to position two or more of the plurality of valves
simultaneously.
30. The turbomachine of claim 28, wherein the control system is
configured to identify the first and second arcs of admission.
31. The turbomachine of claim 30, wherein the control system
regulates the operation of the plurality of valves based on
predetermined acoustic requirements of the turbomachine.
32. The turbomachine of claim 28, wherein the plurality of valves
comprise adjacent first and second valves, and transitioning from
the first valve sequence to the second valve sequence comprises
opening the first and second valves simultaneously, wherein the
second valve begins to be opened before the first valve is
completely open.
33. The turbomachine of claim 28, wherein the diaphragm comprises a
plurality of partitions defining a corresponding plurality of
nozzle bowls.
34. The turbomachine of claim 33, wherein each nozzle bowl
comprises a plurality of nozzles.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to turbomachines, and more
particularly to reducing a turbomachine's acoustic signature.
BACKGROUND
[0002] Turbomachines may produce noise from several fluid dynamic
sources, including wake cutting, high velocity fluid dynamics, and
turbulent flow fields. These noise sources may represent fluid
energy that is not directed into the shaft of a turbomachine. The
turbomachine's efficiency may be increased by transferring more
fluid energy to the shaft. Valve sequencing is one method of
transferring more fluid energy to the shaft.
[0003] Valve sequencing may also affect the acoustic signature of a
turbomachine. In some instances, modifying valve sequencing for
efficiency gains may increase the acoustic signature of a
turbomachine. Thus, there is a need for a valve sequencing system
for controlling a turbomachine's acoustic signature.
SUMMARY
[0004] Embodiments of the present disclosure may provide a method
of controlling a turbomachine having a plurality of valves, the
method including selecting a desired operating load for the
turbomachine, and identifying at least one arc of admission,
wherein each of the plurality of valves is either completely closed
or completely open when the arc of admission is achieved. Further,
the method includes constructing a valve sequencing scheme
configured to activate the identified arc of admission so as to
minimize an acoustic signature of said plurality of valves during
implementation of the desired operating load.
[0005] Embodiments of the present disclosure may further provide a
turbomachine process control mechanism configured to implement a
valve sequencing scheme to control a plurality of valves. The
turbomachine process control mechanism includes a control system
that is adapted to select a desired operating load for the
turbomachine, and identify at least one arc of admission to achieve
the desired operating load. In addition, the control system is
further adapted to construct a valve sequencing scheme configured
to activate the identified arc of admission so as to minimize an
acoustic signature of said plurality of valves during
implementation of the desired operating load.
[0006] Embodiments of the present disclosure may further provide a
turbomachine, that includes a plurality of valves, and a
turbomachine process control mechanism configured to implement a
valve sequencing scheme to control the plurality of valves. The
turbomachine process control mechanism includes a control system
adapted to select a desired operating load for the turbomachine,
and identify at least one arc of admission to achieve the desired
operating load. The control system is further adapted to construct
a valve sequencing scheme configured to activate the identified arc
of admission so as to minimize an acoustic signature of said
plurality of valves during implementation of the desired operating
load.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present disclosure is best understood from the following
detailed description when read with the accompanying Figures. It is
emphasized that, in accordance with the standard practice in the
industry, various features are not drawn to scale. In fact, the
dimensions of the various features may be arbitrarily increased or
reduced for clarity of discussion.
[0008] FIG. 1 illustrates a partial cross-sectional view of an
exemplary valve system of a turbomachine according to one or more
aspects of the present disclosure.
[0009] FIG. 2 illustrates a diagrammatic view of an exemplary valve
system of a turbomachine according to one or more aspects of the
present disclosure.
[0010] FIG. 3 illustrates a graph of exemplary operating conditions
of a turbomachine according to one or more aspects of the present
disclosure.
[0011] FIG. 4a illustrates a graph of exemplary operating
conditions of a turbomachine according to one or more aspects of
the present disclosure.
[0012] FIG. 4b illustrates a graph of exemplary operating
conditions of a turbomachine according to one or more aspects of
the present disclosure.
[0013] FIG. 5 illustrates a flow chart of a method for operating a
turbomachine according to one or more aspects of the present
disclosure.
[0014] FIG. 6 illustrates a flow chart of a method for operating a
turbomachine according to one or more aspects of the present
disclosure.
DETAILED DESCRIPTION
[0015] It is to be understood that the following disclosure
describes several exemplary embodiments for implementing different
features, structures, or functions of the invention. Exemplary
embodiments of components, arrangements, and configurations are
described below to simplify the present disclosure, however, these
exemplary embodiments are provided merely as examples and are not
intended to limit the scope of the invention. Additionally, the
present disclosure may repeat reference numerals and/or letters in
the various exemplary embodiments and across the Figures provided
herein. This repetition is for the purpose of simplicity and
clarity and does not in itself dictate a relationship between the
various exemplary embodiments and/or configurations discussed in
the various Figures. Moreover, the formation of a first feature
over or on a second feature in the description that follows may
include embodiments in which the first and second features are
formed in direct contact, and may also include embodiments in which
additional features may be formed interposing the first and second
features, such that the first and second features may not be in
direct contact. Finally, the exemplary embodiments presented below
may be combined in any combination of ways, i.e., any element from
an exemplary embodiment may be used in any other exemplary
embodiment, without departing from the scope of the disclosure.
[0016] Additionally, certain terms are used throughout the
following description and claims to refer to particular components.
As one skilled in the art will appreciate, various entities may
refer to the same component by different names, and as such, the
naming convention for the elements described herein is not intended
to limit the scope of the invention, unless otherwise specifically
defined herein. Further, the naming convention used herein is not
intended to distinguish between components that differ in name but
not function. Further, in the following discussion and in the
claims, the terms "including" and "comprising" are used in an
open-ended fashion, and thus should be interpreted to mean
"including, but not limited to." All numerical values in this
disclosure may be exact or approximate values unless otherwise
specifically stated. Accordingly, various embodiments of the
disclosure may deviate from the numbers, values, and ranges
disclosed herein without departing from the intended scope.
[0017] FIG. 1 is a partial cross-sectional view of an exemplary
turbomachine 100. The turbomachine 100 is a multistage steam
turbine. However, in other embodiments, the turbomachine 100 may be
any other type of turbine or expander. The turbomachine 100
includes an inlet pipe 101, a steam chest 103, and pipes 110a-e.
One end of each of the pipes 110a-e is coupled to a valve 120a-e,
respectively, and the other end of each of the pipes 110a-e
fluidically communicates with a diaphragm 125 that includes a
plurality of partitions 130a-e that separate portions of the
diaphragm 125. The diaphragm 125 is segmented into a plurality of
nozzle bowls 135a-e that are separated by the partitions 130a-e.
Each of the nozzle bowls 135a-e includes a plurality of nozzles
140, which may also be known as diaphragm segments. The pipes
110a-e are configured to facilitate the flow of process gas to the
nozzle bowls 135a-e. In an exemplary embodiment, the process gas
includes steam, but in other embodiments may include air, products
of combustion, carbon dioxide, or a process fluid.
[0018] The diaphragm 125 may include noise-reducing technology,
which can include noise-reduction arrays. For example, the
noise-reduction arrays may include resonator arrays. Additionally,
or alternatively, noise-reduction arrays may be located proximal to
the diaphragm 125. Exemplary embodiments of noise-reduction arrays
include the technology described in U.S. Pat. Nos. 6,550,574;
6,601,672; 6,669,436; and 6,918,740.
[0019] The nozzle bowls 135a-e are configured to define one or more
arcs of admission. An arc of admission describes those nozzle bowls
135 that receive process gas due to a configuration of one or more
of the open valves 120. In other words, an arc or admission refers
to a set of nozzles 140 receiving process gas. Because there are
multiple sets of nozzles, there are multiple combinations of
nozzles that could receive process gas at any one time. Each
combination can be associated with a particular setting of valves
120. As such a particular arc of admission can be defined by a
particular combination of open and closed valves 120. For example,
a first arc of admission may include opening the valves 120a-c and
closing the valves 120d-e, so that the nozzle bowls 135a, 135d, and
135e will receive the process gas, and nozzle bowls 135b and 135c
will not receive the process gas. Partitions 130a-e prevent process
gas from being transferred between the nozzle bowls 135a-e.
[0020] Each valve 120a-e is coupled to a lifting mechanism 150a-e,
respectively. Each lifting mechanism 150 may include a cam coupled
to a rod. In another exemplary embodiment, the lifting mechanism
150 may include an electromechanical actuator. In various other
exemplary embodiments, the lifting mechanism 150 may be any type of
linear actuator. Any combination of the foregoing may constitute a
valve assembly. Other valve assemblies may include any device or
mechanism configured to control the flow of a process gas to the
nozzle bowls 135a-e.
[0021] In exemplary operation, the lifting mechanisms 150 lift the
respective valves 120 to an open position. When any one of the
valves 120 is open, it allows process gas to flow to the pipe
110a-e that is coupled to the respective valve 120. The process gas
then flows to the respective nozzle bowls 135a-e that are
fluidically coupled to the open valves 120, and across the nozzles
140 thereof.
[0022] Referring now to FIG. 2, the valves 120 and the pipes 110a-e
are shown. Arrows 202a-d illustrate the direction of process gas
moving through the pipes 110a-d. FIG. 2 also shows a simplified
view of the nozzles 140.
[0023] According to an exemplary embodiment of the present
disclosure, a valve sequencing scheme may be used to attenuate
valve noise based on the timing of acoustic-sensitive events and/or
transition events, as will be described in more detail below with
respect to FIGS. 5 and 6. Valve sequencing provides for successive
valve 120 openings and closings so that a particular arc of
admission is achieved at various times (for various power
requirements) during the operation of the turbomachine 100.
[0024] As shown in FIG. 2, the lifting mechanisms 150 are
communicably coupled to a control system 203. A control system 203
includes a microprocessor device configured to receive inputs and
generate outputs in accordance with predetermined algorithms or
instructions. In other embodiments, the control system 203 may be
any computer-based system utilized for regulating the operation of
valves 120. The control system 203 implements the valve sequencing
scheme based on predetermined acoustic requirements by controlling
the movement of the lifting mechanisms 150. The control system 203
increases operational flexibility with respect to selecting an
appropriate arc of admission so as to attenuate valve noise during
a particular operational mode, because it allows the valves 120 to
be controlled in accordance with a valve sequencing scheme,
program, or other algorithm.
[0025] A valve 120 that is positioned at a completely open position
(e.g., leaving the entrance to a pipe 110 substantially
unobstructed) is said to be operating at a "valve point." For
example, in FIG. 2, valves 120a-c are shown at a valve point. In
contrast, valve 120 may be positioned at a completely "closed
position." When a valve 120 is positioned at a completely "closed
position," then corresponding pipe 110 receives no, or
substantially no, gas flow. For example, in FIG. 2, the valve 120e
substantially obstructs the pipe 110e such that no, or
substantially no, gas flows past the valve 120e and into the pipe
110e.
[0026] When a valve 120 is neither completely closed nor completely
open, it may be said to be operating at a "throttling position," as
illustrated in FIG. 2 by valve 120d. When one of the valves 120 is
positioned at a throttling position, the turbomachine 100
experiences a large pressure drop, high Mach number flow, and/or
turbulence caused by process gas flowing around a valve 120. Such
conditions may cause the turbomachine 100 to operate inefficiently.
When none of the valves 120 is operating at a throttling position,
the turbomachine 100 may be said to be operating at an "even valve
point."
[0027] Each valve produces an acoustic signature when gas flows
therethrough. When a valve 120 is positioned at a throttling
position, it generates a larger acoustic signature than when the
valve 120 is operating at either a valve point or a closed
position. The acoustic signature of the valves 120 operating in a
throttling position is referred to as "valve screech" or "valve
noise." The acoustic signature of the valves 120 are a component of
the acoustic signature of the turbomachine 100. To improve the
performance of the turbomachine 100, and reduce valve noise, the
operation sequence of the valves 120 may be configured to minimize
the time that one or more of the valves 120 are operating at a
throttling position. In addition to improving the efficiency of the
turbomachine 100, minimizing the time that one or more of the
valves 120 operates at a throttling position also has the added
benefit of reducing valve noise during turbomachine 100
operation.
[0028] In an embodiment, two or more valves 120 may be moved
simultaneously, rather than moving the valves 120 individually. For
example, if the valves 120 are moved simultaneously from a
completely closed position to a completely open position, or
vice-versa, then the total amount of time that the valves spend at
a throttling position is decreased as compared to consecutively
moving each valve 120 one after the other. This also has the
benefit of reducing the total amount of time that valve noise is
produced.
[0029] Graphs 206a-e show a simplified relationship between entropy
and enthalpy in the process gas flowing through each valve 120, and
further illustrate the gains in efficiency achieved by minimizing
throttling. The graphs 206a-c illustrate the entropy and enthalpy
(i.e., energy) changes experienced in a process gas flow through
the valves 120a-c, which are in the completely open position. As
will be appreciated, the two lines in graphs 206a-c each indicate
the inlet and exit pressure in the valve and nozzle bowl
combination. Accordingly, as illustrated by the arrows, the process
gas enters the valves 120a-c at a given, higher pressure. It then
proceeds to the nozzle bowls 135a-e, where a portion of the
potential energy stored in the flow as pressure is transferred into
rotational mechanical energy, with a commensurate pressure drop
experienced in the gas flow. In contrast, the valve 120d is only
partially open. The graph 206d shows that the steam flow
experiences two pressure drops: first, when flowing through the
partially obstructed valve 120d, and second when transferring
energy to the nozzles 140. This first pressure drop represents
wasted potential energy that is dissipated in several forms,
including valve noise. This increased valve noise represents loss
of energy to the surroundings, and also an increase in a
turbomachine's 100 acoustic signature.
[0030] Based on the foregoing, it can be seen that process gas
passes through the valves 120a-c with minimal loss. In contrast,
valve 120d experiences a comparatively greater throttling loss,
will be noisier, and will require a higher process gas flow to
achieve the same power output. The valve 120e is completely closed,
so there is no flow and no loss.
[0031] FIG. 3 is a graph of process gas flow rate (y-axis) versus
output power (x-axis) during an exemplary operation of the
turbomachine 100. An ideal operating line 310 represents ideal
operating points. That is, the turbomachine 100 that is operating
at a point on the ideal operating line 310 transforms the maximum
amount of potential energy from the flow of process gas to power,
with no potential energy lost to throttling. Such conditions are
more likely to occur when all of the valves 120 are operating at an
even valve point. As explained above, energy is lost when one or
more of the valves 120 are operating at a throttling position.
Under real-world operating conditions, the turbomachine 100 is more
likely to operate at some point along the line 320. The delta
between the ideal operating line 310 and the line 320 represents
available energy that may be lost due to throttling.
[0032] FIG. 4A is a graph of process gas flow rate (y-axis) versus
valve lift (x-axis) representing an exemplary operation of the
turbomachine 100. The control system 203 may be configured to
operate the valves 120 so that valve opening points are timed to
produce a nearly linear response. As shown in FIG. 4a, the
turbomachine initially runs at the first valve operating point, on
the line labeled #1. Prior to, or shortly thereafter, the gains in
power in response to increased flow rate begin to become
attenuated, and the control system 203 changes the sequence, for
example, by opening one or more of the valves 120, thereby moving
the flow rate to the next line (i.e. #2). Thus, the gains from
increased flow rate can be realized similarly to an ideal system,
i.e. closer to linearly. For example, the line labeled #1 may
represent a first set of valves 120 that are completely open, and
the line labeled #2 may represent one or more additional valves 120
that are opened while keeping the first set of valves 120
completely open.
[0033] FIG. 4B is a graph of energy ("H" along the y-axis) versus
entropy ("S" along the x-axis) representing an exemplary operation
of the turbomachine 100. For a given value of H ahead of the valves
120, a fixed amount of energy H is initially provided, which
corresponds to the line labeled P.sub.Line. A small pressure drop
through the open valve 120 brings the steam to line P01: a lower
pressure but the same amount of energy. Expansion through the
nozzles 160 results in a pressure drop to line P02 and the
difference in H between lines P01 and P02 is the energy that has
been converted to do useful work on the nozzles 140.
[0034] If one or more of the valves 120 are only partly open, there
is a larger pressure drop through the partly open valve(s) 120, and
the steam exiting the partly open valves 120 has a lower pressure
P01-Throt, which is lower than P01. This pressure drop is what
restricts the flow through to the partly open valve(s) 120. When
the steam from the partly open valve(s) 120 is expanded to the
lower pressure through the respective set of nozzles 140, it
reaches the P02 line at a different location. The smaller distance
between the P01-Throt and the P02 line means there is less energy
available to do work. The remaining energy has been dissipated in
any of several forms, including noise.
[0035] FIG. 5 is a flow chart representing an exemplary method 500
for operating the turbomachine 100. First, an operating load for
turbomachine 100 is selected. Next, the particular arc of
admission, i.e., nozzle 140 selection, needed to achieve the
operating load is identified. Next, the valve 120 settings required
to implement the identified arc of admission are identified.
Finally, the valves 120 are simultaneously adjusted to yield the
selected operating load. For example, a first turbomachine 100
operating load (e.g., startup) may be associated with a first arc
of admission defined by opening the valves 120a-b, and thereby
provide process gas to the nozzle bowls 135a-b. Further, a second
turbomachine 100 operating load (e.g., operation at a fraction of
maximum power) may be associated with a second arc of admission
defined by opening the valves 120a-d, and thereby provide process
gas to the nozzle bowls 135a-d. Finally, a third turbomachine 100
operating load (e.g. operation at maximum power) may be associated
with a third arc of admission defined by opening the valves 120,
and thereby providing provide a process gas to all of the nozzle
bowls 135a-e. It should be understood that any combination of
operating loads and arc(s) of admission is within the scope of the
present disclosure.
[0036] Thus, one or more turbomachine 100 operating loads may be
defined, and an operating load may be associated with an arc of
admission. Valve sequencing may be used to control the activation
of certain arcs of admission in accordance with associated
operating loads. An arc of admission is "activated" by opening the
valves 120 that are fluidically coupled to the nozzle bowls 135a-e
that define the arc of admission, and closing the valves 120 and
the nozzle bowls 135a-e that are fluidically coupled to the nozzle
bowls 135a-e that are not part of the arc of admission. Further,
valve sequencing may be used to attenuate valve noise in accordance
with one or more of the turbomachine 100 operating loads. For
example, in an exemplary embodiment, the valves 120 may be
sequenced so that the turbomachine 100 is operating at an even
valve point during one or more of the turbomachine 100 operating
loads. In another exemplary embodiment, the valves 120 may be
sequenced to minimize the time that valves 120 spend at a
throttling position.
[0037] According to an exemplary embodiment, the method 500 begins
at block 502, wherein one or more of the turbomachine operating
loads are identified. One or more arcs of admission are defined at
block 504, such that the arcs of admission minimize valve noise
produced during the associated operating load. At block 506, an
operating load is associated with the arc of admission. A valve
sequencing scheme is defined at block 508. Optionally, the size of
one or more of the valves 120 is defined at block 510 to minimize
valve noise produced during the associated operating load.
[0038] Blocks 512 and 514 include operating the turbomachine 100 in
accordance with the valve sequencing scheme. Block 512 includes
activating the arc of admission, and block 514 may include
initiating an operating load associated with the arc of
admission.
[0039] FIG. 6 is a flow chart representing another exemplary method
600 for operating the turbomachine 100. According to an exemplary
embodiment, the method 600 begins at block 610, which includes
identifying an acoustic-sensitive event associated with an acoustic
requirement. Block 620 includes defining a valve sequencing scheme
that meets the acoustic requirement. The valve sequencing scheme
meets the acoustic requirement when the acoustic signature of the
turbomachine 100 satisfies the acoustic requirement. Block 630
includes positioning all valves 120 at either a completely open
position or a completely closed position prior to the
acoustic-sensitive event. Finally, block 640 includes opening or
closing one or more of the valves 120 after the acoustic-sensitive
event.
[0040] According to an exemplary embodiment, an acoustic-sensitive
event is an event that is scheduled to occur during operation of
the turbomachine 100. For example, events such as start-up, reduced
power, or maximum power, may be acoustic-sensitive events. Valve
noise may be undesirable during such acoustic-sensitive events.
Upon identifying one or more acoustic-sensitive events, a valve
sequencing scheme may be implemented to attenuate the production of
noise while the turbomachine is operating at an operating load
associated with, or required by, the turbomachine during the
acoustic-sensitive event.
[0041] In an exemplary embodiment, a valve sequencing scheme is
implemented by defining the timing of valve 120 openings and
closings so that an acoustic-sensitive event occurs before the next
valve 120 in a sequence begins to open, and the valves 120 are
configured to be at an even valve point during the
acoustic-sensitive event. In some exemplary embodiments, a valve
sequencing scheme designed to accommodate one or more
acoustic-sensitive events may sacrifice turbine operation
efficiency in order to obtain a desired acoustical target
result.
[0042] An acoustic-sensitive event may include one or more
transition events. A transition event includes an event where a
first operating load transitions to a second operating load. During
such transition events, valve noise may be undesirable. Upon
identifying one or more transition events, a valve sequencing
scheme is implemented to attenuate turbomachine 100 noise. In an
exemplary embodiment, a valve sequencing system is configured to
time the opening and closing of the valves 120 so that one or more
transition events occur before the next valve 120 in a sequence
begins to open. In some exemplary embodiments, a valve sequencing
scheme designed to accommodate one or more transition events may
sacrifice turbine operation efficiency in order to obtain a desired
acoustical target result.
[0043] The foregoing has outlined features of several embodiments
so that those skilled in the art may better understand the detailed
description that follows. Those skilled in the art should
appreciate that they may readily use the present disclosure as a
basis for designing or modifying other processes and structures for
carrying out the same purposes and/or achieving the same advantages
of the embodiments introduced herein. Those skilled in the art
should also realize that such equivalent constructions do not
depart from the spirit and scope of the present disclosure, and
that they may make various changes, substitutions and alterations
herein without departing from the spirit and scope of the present
disclosure.
* * * * *