U.S. patent application number 12/129280 was filed with the patent office on 2009-12-03 for low noise ejector for a turbomachine.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Kevin Wayne Kinzie, Carl Gerard Schott.
Application Number | 20090297339 12/129280 |
Document ID | / |
Family ID | 41254221 |
Filed Date | 2009-12-03 |
United States Patent
Application |
20090297339 |
Kind Code |
A1 |
Schott; Carl Gerard ; et
al. |
December 3, 2009 |
LOW NOISE EJECTOR FOR A TURBOMACHINE
Abstract
A turbomachine includes a compressor and an ejector. The ejector
includes at least one nozzle having a first end portion that
extends to a second end portion defining a flow region. The second
end portion includes a variable outlet for controlling an airflow
from the compressor.
Inventors: |
Schott; Carl Gerard;
(Simpsonville, SC) ; Kinzie; Kevin Wayne; (Moore,
SC) |
Correspondence
Address: |
CANTOR COLBURN, LLP
20 Church Street, 22nd Floor
Hartford
CT
06103
US
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
41254221 |
Appl. No.: |
12/129280 |
Filed: |
May 29, 2008 |
Current U.S.
Class: |
415/148 |
Current CPC
Class: |
F04D 25/04 20130101;
F04D 25/16 20130101; F05D 2220/3216 20130101; F01D 9/02 20130101;
F02C 9/18 20130101 |
Class at
Publication: |
415/148 |
International
Class: |
F01D 17/14 20060101
F01D017/14 |
Claims
1. A turbomachine comprising: a compressor; and an ejector fluidly
connected to the compressor, the ejector including at least one
nozzle having a first end portion that extends to a second end
portion defining a flow region, the second end portion including a
variable outlet for controlling an airflow from the compressor.
2. The turbomachine according to claim 1, wherein the at least one
nozzle includes a first nozzle and a second nozzle, the second
nozzle being slidingly disposed with the first nozzle.
3. The turbomachine according to claim 2, wherein the first nozzle
includes a first chevron portion that defines a first dimension for
the variable outlet and the second nozzle includes a second chevron
portion that defines a second dimension for the variable outlet,
the second dimension being distinct from the first dimension, the
second nozzle being shiftable between a first position, wherein
airflow from the compressor passes through the variable outlet
configured at the first dimension, to a second position, wherein
the airflow from the compressor passes through the variable outlet
configured at the second dimension.
4. The turbomachine according to claim 1, wherein the variable
outlet is defined by a plurality of chevrons, each of the plurality
of chevrons being pivotally connected to the second end of the at
least one nozzle.
5. The turbomachine according to claim 4, further comprising: a
chevron collar operatively connected to each of the plurality of
chevrons.
6. The turbomachine according to claim 5, wherein the chevron
collar is shiftably mounted to the at least one nozzle.
7. The turbomachine according to claim 4, further comprising: an
actuator rod operatively connected to the chevron collar, the
actuator rod being adapted to selectively shift the chevron collar
between a first position wherein the variable outlet is configured
at the first dimension and a second position, wherein the variable
outlet is configured at the second dimension, the second dimension
being distinct from the first dimension.
8. An ejector for a turbomachine comprises: at least one nozzle
having a first end portion that extends to a second end portion
through a flow region, the second end portion including a variable
outlet configured to control an airflow from a compressor.
9. The ejector according to claim 8, wherein the at least one
nozzle includes a first nozzle and a second nozzle, the second
nozzle being slidingly disposed with the first nozzle.
10. The ejector according to claim 9, wherein the first nozzle
includes a first chevron portion that defines a first dimension for
the variable outlet and the second nozzle includes a second chevron
portion that defines a second dimension for the variable outlet,
the second dimension being distinct from the first dimension, the
second nozzle being shiftable between a first position, wherein
airflow from the compressor passes through the variable outlet
configured at the first dimension, to a second position, wherein
the airflow from the compressor passes through the variable outlet
configured at the second dimension.
11. The ejector according to claim 8, wherein the variable outlet
is defined by a plurality of chevrons, each of the plurality of
chevrons being pivotally connected to the second end of the
ejector.
12. The ejector according to claim 11, further comprising: a
chevron collar operatively connected to each of the plurality of
chevrons.
13. The ejector according to claim 12, wherein the chevron collar
is shiftably mounted to the at least one motive nozzle.
14. The ejector according to claim 12, further comprising: an
actuator rod operatively connected to the chevron collar, the
actuator rod being adapted to selectively shift the chevron collar
between a first position wherein the variable orifice has a first
dimension and a second position, wherein the variable orifice has a
second dimension, the second dimension being distinct from the
first dimension.
15. The ejector according to claim 14, wherein the first dimension
defines a first diameter and the second dimension defines a second
diameter.
16. A method of controlling an airflow through an ejector for a
turbomachine, the method comprising: generating an airflow in a
compressor portion of the turbomachine; guiding the airflow to an
ejector; passing the airflow to a nozzle of the ejector; and
passing the airflow through a variable outlet portion of the
nozzle.
17. The method of claim 16, wherein passing the airflow though the
variable outlet comprises shifting a secondary nozzle portion,
arranged within the nozzle from a first position, wherein the
airflow passes though the variable outlet portion configured at a
first dimension, and a second position wherein the variable outlet
is configured at a second dimension, the second dimension being
distinct from the first dimension.
18. The method of claim 16, wherein passing the airflow though the
variable outlet comprises pivoting a plurality of chevrons arranged
on the nozzle from a first position, wherein the variable outlet
portion is configured at a first dimension, to a second potion
wherein the variable outlet portion is configured at a second
dimension, the second dimension being distinct from the first
dimension.
19. The method of claim 16, further comprising: selectively
shifting a chevron collar to pivot the plurality of chevrons.
20. The method of claim 16, further comprising: passing the airflow
at the desired pressure from the ejector into a turbine portion of
the turbomachine.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the art of ejectors and,
more particularly, to a low noise ejector for a turbomachine.
[0002] At least some known ejectors mix two flow streams, a
high-pressure primary or motive stream and a low-pressure secondary
or suction stream, to produce a discharge flow with pressure
intermediate to or lower than the two input flows. The ejector
nozzle facilitates this mixing process by accelerating the
high-pressure motive flow creating a high speed jet. The high speed
jet is channeled through a mixing tube or chamber to entrain the
low-pressure suction flow. The two mixed flows are then discharged,
typically through a diffuser.
[0003] The motive flow is throttled to match ejector output to a
turbine operating at off-design load and/or ambient conditions.
Existing throttling devices maintain a constant high speed jet
diameter as output is reduced. In such devices, flow is reduced by
lowering an effective velocity of the motive flow. Reducing
velocity of the motive flow in a throttled condition inhibits
entrainment of the ejector and thus limits an overall throttling
range and degrades entrainment performance.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In accordance with one exemplary embodiment of the invention
a turbomachine includes a compressor and an ejector. The ejector
includes at least one nozzle having a first end portion that
extends to a second end portion defining a flow region. The second
end portion includes a variable outlet for controlling an airflow
from the compressor.
[0005] In accordance with another exemplary embodiment of the
invention, an ejector for a turbomachine includes at least one
nozzle having a first end portion that extends to a second end
portion defining a flow region. The second end portion includes a
variable outlet configured to controlling an airflow from a
compressor.
[0006] In accordance with yet another exemplarily embodiment of the
invention, a method of controlling an airflow through an ejector
for a turbomachine includes generating an airflow in a compressor
portion of the turbomachine, guiding the airflow to an ejector,
passing the airflow to a nozzle of the ejector, and passing the
airflow through a variable outlet portion of the nozzle.
[0007] Additional features and advantages are realized through the
techniques of exemplary embodiments of the present invention. Other
embodiments and aspects of the invention are described in detail
herein and are considered a part of the claimed invention. For a
better understanding of the invention with advantages and features
thereof, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic representation of a gas turbine engine
having a low noise ejector including a nozzle having a selectively
variable orifice in accordance with an exemplary embodiment of the
invention;
[0009] FIG. 2 is a partial schematic representation of a nozzle
having a selectively variable orifice in accordance with an
exemplary embodiment of the invention illustrating the selectively
variable orifice in a first configuration;
[0010] FIG. 3 is a partial schematic representation of the nozzle
of FIG. 2 illustrating the selectively variable orifice in a second
configuration;
[0011] FIG. 4 is a partial schematic representation of a nozzle
having a selectively variable orifice in accordance with another
exemplary embodiment of the invention illustrating the selectively
variable orifice in a first configuration; and
[0012] FIG. 5 is a partial schematic representation of the nozzle
of FIG. 4 illustrating the selectively variable orifice in a second
configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0013] With initial reference to FIG. 1, a turbomachine, shown in
the form of a gas turbine engine constructed in accordance with an
exemplary embodiment of the invention, is indicated generally at 2.
Turbine engine 2 includes a compressor 4 having a plurality of
compressor stages, four of which are indicated at 6 through 9.
Compressor 4 is operatively connected to a turbine 12 via a shaft
14. Turbine 12 includes a plurality of turbine stages, three of
which are indicated at 17 through 19. Turbine 2 also includes a
cooling system 30 that directs a cooling airflow from compressor 4
to turbine 12. That is, cooling air is extracted from various ones
of stages 6 through 9 and passed to corresponding ones of stages 17
through 19 of turbine 12.
[0014] Towards that end, cooling system 30 includes a first cooling
circuit 40 that interconnects compressor stage 7 with turbine stage
19. In the embodiment shown, compressor stage 7 is a mid-pressure
stage that is connected to a corresponding mid-pressure stage 19 of
turbine 12. Cooling system 30 also includes a second cooling
circuit 44 that interconnects compressor stage 8 with turbine stage
18. Compressor stage 8 is at a higher pressure than stage 7 and
thus in connected to stage 18, which, likewise, is at a pressure
higher than stage 17. In addition, cooling system 30 is shown to
include a bypass circuit 47 having a bypass valve 48 that is
selectively operated to maintain internal pressure within turbine
engine 2.
[0015] In order to utilize as little high-pressure air from
compressor 4 as possible, second cooling circuit 44 is provided
with an ejector 55 that is operatively connected to first cooling
circuit 40 via a connector circuit 58. With this arrangement, a
high pressure primary or motive airflow passing through ejector 55
draws in a portion of a lower pressure secondary or suction airflow
from first cooling circuit 58. The high-pressure airflow and
low-pressure airflow mix to form a combined airflow that is
directed through a primary or motive nozzle 60 located within
ejector 55. Motive nozzle 60 accelerates the high pressure fluid to
a higher speed to substantially match a pressure and speed of fluid
within, for example, turbine stage 18. However, as pressure within
turbine stage 18 varies over an operating range of turbine 12,
ejector 55, as will be discussed more fully below, is selectively
adjustable in order to control pressures within second cooling
circuit 44 to match pressures within turbine stage 18 over a wide
operating range of turbine 12.
[0016] Reference will now be made to FIGS. 2 and 3 in describing
motive nozzle 60 constructed in accordance with a first exemplary
embodiment of the invention. As shown, motive nozzle 60 includes a
first end portion 70 that extends to a second end portion 71
through an intermediate portion 72 defining a flow region 75. As
will be discussed more fully below, second end portion 71 includes
a variable outlet 78. In accordance with the exemplary embodiment,
variable outlet 78 is defined, in part, by a chevron 79 arranged at
second end portion 71. Chevron 79 is designed to lower an overall
noise output from ejector 55. Chevron 79 is configured to extend
towards a centerline (not separately labeled) of ejector 55 in
order to control airflow. Chevron 79 defines a first dimension 85
for variable outlet 78.
[0017] In further accordance with the exemplary embodiment shown,
ejector 55 includes a secondary motive nozzle 88 arranged within
motive nozzle 60. Secondary motive nozzle 88 is operatively
connected to an actuator shaft 91 through a plurality of struts,
one of which is indicated at 93. As will be discussed more fully
below, actuator shaft 91 is selectively operated in order to shift
secondary motive nozzle 88 within flow region 75 in order to
control an overall output from ejector 55. Towards that end,
secondary nozzle 88 includes a first end portion 97 that extends to
a second end portion 98 through an intermediate portion 99.
Intermediate portion 99 defines a secondary chevron 104 that
correspondingly defines a second dimension for variable outlet
78.
[0018] With this arrangement, during base load operation of turbine
2, secondary motive nozzle 88 is shifted to a first configuration
as indicated in FIG. 2 wherein air passing through flow region 75
passes through variable outlet 78 configured at first dimension 85.
However, during off baseload operation or, when ambient air
temperatures are outside of design parameters, secondary motive
nozzle 88 is shifted towards a second configuration as indicated in
FIG. 3 where the airflow flowing through flow region 75 is guided
through variable outlet 78 configured at the second dimension 107.
More specifically, in the second configuration illustrated in FIG.
3, secondary chevron 104 abuts chevron 79 closing or narrowing
variable outlet 78. Of course, depending on the particular
operating speed and/or, ambient air conditions, secondary motive
nozzle 88 can be shifted to any one of a plurality of intermediate
positions (not shown) in order to establish any number of
intermediate dimensions for variable outlet 78 to produce a desired
airflow pressure/speed to provide cooling air to turbine stage 18.
With this arrangement, ejector 55 is selectively configurable to
produce a wide range of pressures/volumes so as to match operating
pressures within a turbine stage across a broad operating range of
turbine 2.
[0019] Reference will now be made to FIGS. 4 and 5 in describing a
motive nozzle 120 constructed in accordance with another exemplary
embodiment of the invention. As shown, nozzle 120 includes a motive
pipe 124 having a first end portion 128 that extends to a second
end portion 129 through an intermediate portion 130 so as to define
a flow region 132. In a manner similar to that described above
second end portion 129 includes a variable outlet 132. Nozzle 120
further includes a plurality of chevrons, one of which is indicated
at 136 which, as will be discussed more fully below, define an
outlet geometry or dimension for variable outlet 132. In a manner
also similar to that described above, chevrons 136 extend towards a
centerline (not separately labeled) of ejector 55 so as to minimize
noise output during turbine operation. In the embodiment shown,
each chevron 136 includes a first end section 138 that extends to a
second end section 139 through an intermediate section 140. In
accordance with the exemplary embodiment shown, each chevron 136 is
pivotally mounted to motive pipe 124 and thus includes a hinge 142.
As will be discussed more fully below, chevrons 136 are selectively
pivotable between a first position, illustrated in FIG. 4 and a
second position, indicated in FIG. 5.
[0020] In order to control the selective movement of chevrons 136,
nozzle 120 is provided with a chevron collar 154 that is slidingly
mounted to motive pipe 124. Chevron collar 154 includes a first end
157 that extends to a second end 158. Second end 158 is operatively
connected to first end section 138 of the plurality of chevrons
136. First end section 157 is operatively connected to an actuator
rod 161 that is selectively shiftable in order to move or position
chevrons 136 between the first position illustrated in FIG. 4 and
the second position illustrated in FIG. 5.
[0021] During normal or baseload operation of turbine 2, actuator
rod 161 is shifted so as to cause chevron collar 154 to move
chevrons 136 to the first configuration illustrated in FIG. 4
establishing an outlet portion or orifice 165 having a first
dimension 166. In this manner, a sufficient airflow passes through
flow region 132 into compressor stage 18. During off base load
operations or, when ambient temperatures are outside design
parameters, actuator rod 161 acts against chevron collar 154 to
close chevrons 136 shifting orifice 165 to a second dimension 169
that is smaller than first dimension 166. In this manner, cooling
air at a sufficient volume and a sufficient temperature is passed
to turbine stage 18 in order to accommodate off base load
operation.
[0022] At this point, it should be appreciated that ejector 55 in
accordance with provides a selectively variable airflow output thus
enabling cooling circuit flow to be tailored to pressure conditions
within turbine section of a turbine engine across wide operating
ranges. That is, the ejector, in accordance with the exemplary
embodiment of the invention, is more tunable across a broader range
or operating conditions so as to provide more control at hotter
temperatures and additional adjustments to provide cooling air
across a wider operating range. It should also be understood that
the variable outlet can be formed using a variety of different
structures.
[0023] In general, 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 examples are intended to be
within the scope of exemplary embodiments of the present invention
if they have 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
language of the claims.
* * * * *