U.S. patent application number 15/073820 was filed with the patent office on 2016-09-29 for apparatus, system, and method for compressing a process fluid.
This patent application is currently assigned to DRESSER-RAND COMPANY. The applicant listed for this patent is Paul Morrison Brown, Mark J. Kuzdzal, Pascal Lardy, Logan Marsh Sailer, Silvano R. Saretto, James M. Sorokes, Ravichandra Srinivasan. Invention is credited to Paul Morrison Brown, Mark J. Kuzdzal, Pascal Lardy, Logan Marsh Sailer, Silvano R. Saretto, James M. Sorokes, Ravichandra Srinivasan.
Application Number | 20160281727 15/073820 |
Document ID | / |
Family ID | 56974037 |
Filed Date | 2016-09-29 |
United States Patent
Application |
20160281727 |
Kind Code |
A1 |
Lardy; Pascal ; et
al. |
September 29, 2016 |
APPARATUS, SYSTEM, AND METHOD FOR COMPRESSING A PROCESS FLUID
Abstract
A supersonic compressor including an inlet configured to receive
and flow therethrough a process fluid. The supersonic compressor
may further include a rotary shaft and a centrifugal impeller
coupled therewith. The centrifugal impeller may be configured to
impart energy to the process fluid received and to discharge the
process fluid therefrom in at least a partially radial direction at
an exit absolute Mach number of about one or greater. The
supersonic compressor may further include a static diffuser
circumferentially disposed about the centrifugal impeller and
configured to receive the process fluid therefrom and convert the
energy imparted. The supersonic compressor may further include a
collector fluidly coupled to and configured to collect the process
fluid exiting the diffuser, such that the supersonic compressor is
configured to provide a compression ratio of at least about
8:1.
Inventors: |
Lardy; Pascal; (Notre Dame
du Bec, FR) ; Sorokes; James M.; (Olean, NY) ;
Kuzdzal; Mark J.; (Allegany, NY) ; Brown; Paul
Morrison; (Seattle, WA) ; Saretto; Silvano R.;
(Snoqualmie, WA) ; Srinivasan; Ravichandra;
(Renton, WA) ; Sailer; Logan Marsh; (Seattle,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lardy; Pascal
Sorokes; James M.
Kuzdzal; Mark J.
Brown; Paul Morrison
Saretto; Silvano R.
Srinivasan; Ravichandra
Sailer; Logan Marsh |
Notre Dame du Bec
Olean
Allegany
Seattle
Snoqualmie
Renton
Seattle |
NY
NY
WA
WA
WA
WA |
FR
US
US
US
US
US
US |
|
|
Assignee: |
DRESSER-RAND COMPANY
Olean
NY
|
Family ID: |
56974037 |
Appl. No.: |
15/073820 |
Filed: |
March 18, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62139027 |
Mar 27, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/441 20130101;
F04D 13/06 20130101; F04D 17/10 20130101; F04D 21/00 20130101; F04D
1/00 20130101; F04D 25/06 20130101; F04D 27/0292 20130101 |
International
Class: |
F04D 29/041 20060101
F04D029/041; F04D 13/06 20060101 F04D013/06; F04D 29/44 20060101
F04D029/44; F04D 1/00 20060101 F04D001/00 |
Goverment Interests
STATEMENT OF GOVERNMENT INTEREST
[0002] This invention was made with government support under
Government Contract No. DOE-DE-FE0000493 awarded by the U.S.
Department of Energy. The government has certain rights in the
invention.
Claims
1. A supersonic compressor comprising: a housing; an inlet coupled
to or integral with the housing and defining an inlet passageway
configured to receive and flow therethrough a process fluid; a
plurality of inlet guide vanes coupled to the housing and extending
into the inlet passageway; a rotary shaft configured to be driven
by a driver; a centrifugal impeller coupled with the rotary shaft
and fluidly coupled to the inlet passageway via a plurality of flow
passages formed by the centrifugal impeller, the centrifugal
impeller having a tip and configured to impart energy to the
process fluid received via the inlet passageway and to discharge
the process fluid from the tip via the plurality of flow passages
in at least a partially radial direction at an exit absolute Mach
number of about one or greater; a balance piston configured to
balance an axial thrust generated by the centrifugal impeller; a
static diffuser circumferentially disposed about the tip of the
centrifugal impeller and bounded in part by a shroud wall and a hub
wall defining an annular diffuser passageway therebetween, the
static diffuser configured to receive the process fluid from the
plurality of flow passages of the centrifugal impeller and convert,
within the annular diffuser passageway, the energy imparted; and a
collector fluidly coupled to the annular diffuser passageway and
configured to collect the process fluid exiting the annular
diffuser passageway, wherein the supersonic compressor is
configured to provide a compression ratio of at least about
8:1.
2. The supersonic compressor of claim 1, wherein: the plurality of
inlet guide vanes are pivotably coupled to the housing; the balance
piston is integral with the centrifugal impeller; and the collector
is a discharge volute configured to discharge the process fluid to
a downstream processing component.
3. The supersonic compressor of claim 2, wherein the plurality of
inlet guide vanes are configured to condition the process fluid
flowing therethrough to yield one or more predetermined fluid
properties selected from the group consisting of a flow pattern, a
velocity, a mass flow rate, a pressure, and a temperature.
4. The supersonic compressor of claim 1, wherein: the supersonic
compressor is configured to provide a compression ratio of at least
about 10:1; the process fluid comprises carbon dioxide; the
centrifugal impeller is configured to discharge the process fluid
from the tip via the plurality of flow passages in at least a
partially radial direction at an exit absolute Mach number of about
1.3 or greater; and the centrifugal impeller is further configured
to rotate via the rotary shaft at a rotational speed of about 500
meters per second or greater.
5. The supersonic compressor of claim 1, wherein the static
diffuser is a vaneless diffuser configured to discharge the process
fluid flowing therethrough at a subsonic velocity.
6. The supersonic compressor of claim 1, wherein the centrifugal
impeller comprises a hub and a plurality of blades extending
therefrom and forming the plurality of flow passages, each of the
plurality of blades comprising a leading edge and at least one
leading edge of the plurality of blades is meridionally spaced from
at least one other leading edge of the plurality of blades.
7. The supersonic compressor of claim 1, further comprising a
shroud having an abradable material disposed adjacent a plurality
of blades extending from a hub of the centrifugal impeller.
8. The supersonic compressor of claim 1, wherein the process fluid
comprises carbon dioxide.
9. The supersonic compressor of claim 8, wherein the process fluid
comprises about ninety percent carbon dioxide.
10. The supersonic compressor of claim 1, wherein the centrifugal
impeller is an open-faced impeller.
11. A compression system comprising: a driver comprising a drive
shaft, the driver configured to provide the drive shaft with
rotational energy; a supersonic compressor operatively coupled to
the driver via a rotary shaft integral with or coupled with the
drive shaft, the supersonic compressor comprising: a compressor
chassis; an inlet defining an inlet passageway configured to flow a
process fluid therethrough, the process fluid having a first
velocity and a first pressure energy; a plurality of inlet guide
vanes pivotally coupled to the compressor chassis and extending
into the inlet passageway; a centrifugal impeller coupled with the
rotary shaft and fluidly coupled to the inlet passageway via a
plurality of flow passages formed by the centrifugal impeller, the
centrifugal impeller having a tip and configured to increase the
first velocity and the first pressure energy of the process fluid
received via the inlet passageway and to discharge the process
fluid from the tip via the plurality of flow passages in at least a
partially radial direction having a second velocity and a second
pressure energy, the second velocity being a supersonic velocity
having an exit absolute Mach number of about one or greater; a
static diffuser circumferentially disposed about the tip of the
centrifugal impeller and defining an annular diffuser passageway
fluidly coupled to the plurality of flow passages, the annular
diffuser passageway configured to receive and reduce the second
velocity of the process fluid to a third velocity and increase the
second pressure energy to a third pressure energy, the third
velocity being a subsonic velocity; and a discharge volute fluidly
coupled to the annular diffuser passageway and configured to
receive the process fluid flowing therefrom, wherein the supersonic
compressor is configured to provide a compression ratio of at least
about 8:1.
12. The compression system of claim 11, wherein the supersonic
compressor further comprises: a shroud having an abradable material
disposed adjacent a plurality of blades extending from a hub of the
centrifugal impeller and forming the plurality of flow passages
fluidly coupled to the annular diffuser passageway and the inlet
passageway; and a balance piston integral with the centrifugal
impeller and configured to balance an axial thrust generated by the
centrifugal impeller, wherein the supersonic compressor is
configured to provide a compression ratio of at least about 10:1,
the process fluid comprises carbon dioxide, and the second velocity
has an exit absolute Mach number of about 1.3 or greater.
13. The compression system of claim 11, wherein the static diffuser
is a vaneless diffuser bounded in part by a shroud wall and a hub
wall defining the annular diffuser passageway therebetween.
14. The compression system of claim 13, wherein either or both the
shroud wall and the hub wall are contoured, such that an axial
width of the annular diffuser passageway is reduced as the shroud
wall and the hub wall extend radially outward.
15. The compression system of claim 11, wherein the static diffuser
comprises a plurality of low solidity diffuser vanes extending into
the annular diffuser passageway.
16. The compression system of claim 15, wherein the static diffuser
is bounded in part by a shroud wall and a hub wall defining the
annular diffuser passageway therebetween, and the plurality of low
solidity diffuser vanes are arranged in tandem within the annular
diffuser passageway and extend into the annular diffuser passageway
from the shroud wall, the hub wall, or both the shroud wall and the
hub wall.
17. A method for compressing a process fluid, comprising: driving a
rotary shaft of a supersonic compressor via a driver operatively
coupled with the supersonic compressor; establishing a fluid
property of the process fluid flowing through an inlet passageway
defined by an inlet of the supersonic compressor via at least one
moveable inlet guide vane pivotally coupled to a housing of the
supersonic compressor and extending into the inlet passageway;
rotating a centrifugal impeller mounted about the rotary shaft,
such that the process fluid flowing though the inlet passageway of
the supersonic compressor is drawn into the centrifugal impeller
and discharged from a tip of the centrifugal impeller via a
plurality of flow passages, the discharged process fluid having a
supersonic velocity with an exit absolute Mach number of about 1.0
or greater; and flowing the discharged process fluid having a
supersonic velocity through an annular diffuser passageway defined
by a static diffuser and fluidly coupled to the plurality of flow
passages such that a pressure energy of the discharged process
fluid is increased, thereby compressing the discharged process
fluid at a compression ratio of about 8:1 or greater.
18. The method of claim 17, further comprising: adjusting the at
least one moveable inlet guide vane to establish the fluid property
of the process fluid, wherein the fluid property is selected from
the group consisting of a flow pattern, a first velocity, a mass
flow rate, a pressure, and a temperature, and wherein the process
fluid comprises carbon dioxide.
19. The method of claim 17, wherein: the static diffuser is a
vaneless diffuser bounded in part by a shroud wall and a hub wall
defining the annular diffuser passageway therebetween, the shroud
wall bounding the annular diffuser passageway is a straight wall, a
contoured wall, or a combination thereof, and the hub wall bounding
the annular diffuser passageway is a straight wall, a contoured
wall, or a combination thereof.
20. The method of claim 17, wherein: the static diffuser is a vaned
diffuser bounded in part by a shroud wall and a hub wall defining
the annular diffuser passageway therebetween, and the static
diffuser comprises a plurality of low solidity diffuser vanes
extending into the annular diffuser passageway from either or both
the shroud wall and the hub wall.
Description
[0001] This application claims the benefit of U.S. Provisional
patent application having Ser. No. 62/139,027, which was filed Mar.
27, 2015. The aforementioned patent application is hereby
incorporated by reference in its entirety into the present
application to the extent consistent with the present
application.
BACKGROUND
[0003] Compressors and systems including compressors have been
developed and are utilized in a myriad of industrial processes
(e.g., petroleum refineries, offshore oil production platforms, and
subsea process control systems) to compress gas, typically by
applying mechanical energy to the gas in a low pressure environment
and transporting the gas to and compressing the gas within a higher
pressure environment. The compressed gas may be utilized to perform
work or for operation of one or more downstream process components.
As conventional compressors are increasingly used in offshore oil
production facilities and other environments facing space
constraints, there is an ever-increasing demand for smaller,
lighter, and more compact compressors. In addition to the
foregoing, it is desirable for commercial purposes that the compact
compressors achieve higher compression ratios (e.g., 10:1 or
greater) while maintaining a compact arrangement.
[0004] In view of the foregoing, skilled artisans may often attempt
to achieve the higher compression ratios by increasing the number
of compression stages within the compact compressor. Increasing the
number of compression stages, however, increases the overall number
of components (e.g., impellers and/or other intricate parts)
required to achieve the desired compressor throughput (e.g., mass
flow) and pressure rise to achieve the higher compression ratios.
Increasing the number of components required in these compact
compressors may often increase length requirements for the rotary
shaft and/or increase distance requirements between rotary shaft
bearings. The imposition of these requirements often results in
larger, less compact compressors as compared to compact compressors
utilizing fewer compression stages. Further, in many cases,
increasing the number of compression stages in the compact
compressors may still not provide the desired higher compression
ratios, or if the desired compression ratios are achieved, the
compact compressors may exhibit decreased efficiencies that make
the compact compressors commercially undesirable.
[0005] What is needed, therefore, is an efficient compression
system that provides increased compression ratios in a compact
arrangement that is economically and commercially viable.
SUMMARY
[0006] Embodiments of the disclosure may provide a supersonic
compressor. The supersonic compressor may include a housing and an
inlet coupled to or integral with the housing and defining an inlet
passageway configured to receive and flow therethrough a process
fluid. The supersonic compressor may also include a plurality of
inlet guide vanes coupled to the housing and extending into the
inlet passageway. The supersonic compressor may further include a
rotary shaft configured to be driven by a driver, and a centrifugal
impeller coupled with the rotary shaft and fluidly coupled to the
inlet passageway via a plurality of flow passages formed by the
centrifugal impeller. The centrifugal impeller may have a tip and
be configured to impart energy to the process fluid received via
the inlet passageway and to discharge the process fluid from the
tip via the plurality of flow passages in at least a partially
radial direction at an exit absolute Mach number of about one or
greater. The supersonic compressor may also include a balance
piston configured to balance an axial thrust generated by the
centrifugal impeller. The supersonic compressor may further include
a static diffuser circumferentially disposed about the tip of the
centrifugal impeller and bounded in part by a shroud wall and a hub
wall defining an annular diffuser passageway therebetween. The
static diffuser may be configured to receive the process fluid from
the plurality of flow passages of the centrifugal impeller and
convert, within the annular diffuser passageway, the energy
imparted. The supersonic compressor may further include a collector
fluidly coupled to the annular diffuser passageway and configured
to collect the process fluid exiting the annular diffuser
passageway, such that the supersonic compressor is configured to
provide a compression ratio of at least about 8:1.
[0007] Embodiments of the disclosure may further provide a
compression system. The compression system may include a driver
including a drive shaft, the driver configured to provide the drive
shaft with rotational energy, and a supersonic compressor
operatively coupled to the driver via a rotary shaft integral with
or coupled with the drive shaft. The supersonic compressor may
include a compressor chassis and an inlet defining an inlet
passageway configured to flow a process fluid therethrough. The
process fluid may have a first velocity and a first pressure
energy. The supersonic compressor may also include a plurality of
inlet guide vanes pivotally coupled to the compressor chassis and
extending into the inlet passageway, and a centrifugal impeller
coupled with the rotary shaft and fluidly coupled to the inlet
passageway via a plurality of flow passages formed by the
centrifugal impeller. The centrifugal impeller may have a tip and
may be configured to increase the first velocity and the first
pressure energy of the process fluid received via the inlet
passageway and to discharge the process fluid from the tip via the
plurality of flow passages in at least a partially radial direction
having a second velocity and a second pressure energy. The second
velocity may be a supersonic velocity having an exit absolute Mach
number of about one or greater. The supersonic compressor may
further include a static diffuser circumferentially disposed about
the tip of the centrifugal impeller and defining an annular
diffuser passageway fluidly coupled to the plurality of flow
passages. The annular diffuser passageway may be configured to
receive and reduce the second velocity of the process fluid to a
third velocity and increase the second pressure energy to a third
pressure energy, the third velocity being a subsonic velocity. The
supersonic compressor may also include a discharge volute fluidly
coupled to the annular diffuser passageway and configured to
receive the process fluid flowing therefrom, such that the
supersonic compressor is configured to provide a compression ratio
of at least about 8:1.
[0008] Embodiments of the disclosure may further provide a method
for compressing a process fluid. The method may include driving a
rotary shaft of a supersonic compressor via a driver operatively
coupled with the supersonic compressor. The method may also include
establishing a fluid property of the process fluid flowing through
an inlet passageway defined by an inlet of the supersonic
compressor via at least one moveable inlet guide vane pivotally
coupled to a housing of the supersonic compressor and extending
into the inlet passageway. The method may further include rotating
a centrifugal impeller mounted about the rotary shaft, such that
the process fluid flowing though the inlet passageway of the
supersonic compressor is drawn into the centrifugal impeller and
discharged from a tip of the centrifugal impeller via a plurality
of flow passages. The discharged process fluid may have a
supersonic velocity with an exit absolute Mach number of about 1.0
or greater. The method may also include flowing the discharged
process fluid having a supersonic velocity through an annular
diffuser passageway defined by a static diffuser and fluidly
coupled to the plurality of flow passages such that a pressure
energy of the discharged process fluid is increased, thereby
compressing the discharged process fluid at a compression ratio of
about 8:1 or greater.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] 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.
[0010] FIG. 1 illustrates a schematic view of an exemplary
compression system, according to one or more embodiments.
[0011] FIG. 2 illustrates a cross-sectional view of an exemplary
compressor, which may be included in the compression system of FIG.
1, according to one or more embodiments.
[0012] FIG. 3 illustrates a perspective view of an exemplary
impeller, which may be included in the compressor of FIG. 2,
according to one or more embodiments.
[0013] FIG. 4 illustrates a front view of a portion of the impeller
of FIG. 3 and a portion of an exemplary vaneless static diffuser
that may be included in the compressor of FIG. 2, according to one
or more embodiments.
[0014] FIG. 5 illustrates a front view of a portion of the impeller
of FIG. 3 and a portion of an exemplary vaned static diffuser that
may be included in the compressor of FIG. 2, according to one or
more embodiments.
[0015] FIG. 6 is a flowchart depicting an exemplary method for
compressing a process fluid, according to one or more
embodiments.
DETAILED DESCRIPTION
[0016] 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
one exemplary embodiment may be used in any other exemplary
embodiment, without departing from the scope of the disclosure.
[0017] 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. Additionally, 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.
Furthermore, as it is used in the claims or specification, the term
"or" is intended to encompass both exclusive and inclusive cases,
i.e., "A or B" is intended to be synonymous with "at least one of A
and B," unless otherwise expressly specified herein.
[0018] FIG. 1 illustrates a schematic view of an exemplary
compression system 100, according to one or more embodiments. The
compression system 100 may include one or more compressors 102 (one
is shown) configured to pressurize a process fluid. In an exemplary
embodiment, the compression system 100 may have a compression ratio
of at least about 6:1 or greater. For example, the compression
system 100 may compress the process fluid to a compression ratio of
about 6:1, about 6.1:1, about 6.2:1, about 6.3:1, about 6.4:1,
about 6.5:1, about 6.6:1, about 6.7:1, about 6.8:1, about 6.9:1,
about 7:1, about 7.1:1, about 7.2:1, about 7.3:1, about 7.4:1,
about 7.5:1, about 7.6:1, about 7.7:1, about 7.8:1, about 7.9:1,
about 8:1, about 8.1:1, about 8.2:1, about 8.3:1, about 8.4:1,
about 8.5:1, about 8.6:1, about 8.7:1, about 8.8:1, about 8.9:1,
about 9:1, about 9.1:1, about 9.2:1, about 9.3:1, about 9.4:1,
about 9.5:1, about 9.6:1, about 9.7:1, about 9.8:1, about 9.9:1,
about 10:1, about 10.1:1, about 10.2:1, about 10.3:1, about 10.4:1,
about 10.5:1, about 10.6:1, about 10.7:1, about 10.8:1, about
10.9:1, about 11:1, about 11.1:1, about 11.2:1, about 11.3:1, about
11.4:1, about 11.5:1, about 11.6:1, about 11.7:1, about 11.8:1,
about 11.9:1, about 12:1, about 12.1:1, about 12.2:1, about 12.3:1,
about 12.4:1, about 12.5:1, about 12.6:1, about 12.7:1, about
12.8:1, about 12.9:1, about 13:1, about 13.1:1, about 13.2:1, about
13.3:1, about 13.4:1, about 13.5:1, about 13.6:1, about 13.7:1,
about 13.8:1, about 13.9:1, about 14:1, or greater.
[0019] The compression system 100 may also include, amongst other
components, a driver 104 operatively coupled to the compressor 102
via a drive shaft 106. The driver 104 may be configured to provide
the drive shaft 106 with rotational energy. In an exemplary
embodiment, the drive shaft 106 may be integral with or coupled
with a rotary shaft 108 of the compressor 102, such that the
rotational energy of the drive shaft 106 is imparted to the rotary
shaft 108. The drive shaft 106 may be coupled with the rotary shaft
108 via a gearbox (not shown) including a plurality of gears
configured to transmit the rotational energy of the drive shaft 106
to the rotary shaft 108 of the compressor 102, such that the drive
shaft 106 and the rotary shaft 108 may spin at the same speed,
substantially similar speeds, or differing speeds and rotational
directions.
[0020] The driver 104 may be a motor and more specifically may be
an electric motor, such as a permanent magnet motor, and may
include a stator (not shown) and a rotor (not shown). It will be
appreciated, however, that other embodiments may employ other types
of electric motors including, but not limited to, synchronous
motors, induction motors, and brushed DC motors. The driver 104 may
also be a hydraulic motor, an internal combustion engine, a steam
turbine, a gas turbine, or any other device capable of driving the
rotary shaft 108 of the compressor 102 either directly or through a
power train.
[0021] In an exemplary embodiment, the compressor 102 may be a
direct-inlet centrifugal compressor. In other embodiments, the
compressor 102 may be a back-to-back compressor. The direct-inlet
centrifugal compressor may be, for example, a version of a
Dresser-Rand Pipeline Direct Inlet (PDI) centrifugal compressor
manufactured by the Dresser-Rand Company of Olean, N.Y. The
compressor 102 may have a center-hung rotor configuration or an
overhung rotor configuration, as illustrated in FIG. 1. In an
exemplary embodiment, the compressor 102 may be an axial-inlet
centrifugal compressor. In another embodiment, the compressor 102
may be a radial-inlet centrifugal compressor. As previously
discussed, the compression system 100 may include one or more
compressors 102. For example, the compression system 100 may
include a plurality of compressors (not shown). In another example,
illustrated in FIG. 1, the compression system 100 may include a
single compressor 102. The compressor 102 may be a supersonic
compressor or a subsonic compressor. In at least one embodiment,
the compression system 100 may include a plurality of compressors
(not shown), and at least one compressor of the plurality of
compressors is a subsonic compressor. In another embodiment,
illustrated in FIG. 1, the compression system 100 includes a single
compressor 102, and the single compressor 102 is a supersonic
compressor.
[0022] The compressor 102 may include one or more stages (not
shown). In at least one embodiment, the compressor 102 may be a
single-stage compressor. In another embodiment, the compressor 102
may be a multi-stage centrifugal compressor. Each stage (not shown)
of the compressor 102 may be a subsonic compressor stage or a
supersonic compressor stage. In an exemplary embodiment, the
compressor 102 may include a single supersonic compressor stage. In
another embodiment, the compressor 102 may include a plurality of
subsonic compressor stages. In yet another embodiment, the
compressor 102 may include a subsonic compressor stage and a
supersonic compressor stage. Any one or more stages of the
compressor 102 may have a compression ratio greater than about 1:1.
For example, any one or more stages of the compressor 102 may have
a compression ratio of about 1.1:1, about 1.2:1, about 1.3:1, about
1.4:1, about 1.5:1, about 1.6:1, about 1.7:1, about 1.8:1, about
1.9:1, about 2:1, about 2.1:1, about 2.2:1, about 2.3:1, about
2.4:1, about 2.5:1, about 2.6:1, about 2.7:1, about 2.8:1, about
2.9:1, about 3:1, about 3.1:1, about 3.2:1, about 3.3:1, about
3.4:1, about 3.5:1, about 3.6:1, about 3.7:1, about 3.8:1, about
3.9:1, about 4:1, about 4.1:1, about 4.2:1, about 4.3:1, about
4.4:1, about 4.5:1, about 4.6:1, about 4.7:1, about 4.8:1, about
4.9:1, about 5:1, about 5.1:1, about 5.2:1, about 5.3:1, about
5.4:1, about 5.5:1, about 5.6:1, about 5.7:1, about 5.8:1, about
5.9:1, about 6:1, about 6.1:1, about 6.2:1, about 6.3:1, about
6.4:1, about 6.5:1, about 6.6:1, about 6.7:1, about 6.8:1, about
6.9:1, about 7:1, about 7.1:1, about 7.2:1, about 7.3:1, about
7.4:1, about 7.5:1, about 7.6:1, about 7.7:1, about 7.8:1, about
7.9:1, about 8.0:1, about 8.1:1, about 8.2:1, about 8.3:1, about
8.4:1, about 8.5:1, about 8.6:1, about 8.7:1, about 8.8:1, about
8.9:1, about 9:1, about 9.1:1, about 9.2:1, about 9.3:1, about
9.4:1, about 9.5:1, about 9.6:1, about 9.7:1, about 9.8:1, about
9.9:1, about 10:1, about 10.1:1, about 10.2:1, about 10.3:1, about
10.4:1, about 10.5:1, about 10.6:1, about 10.7:1, about 10.8:1,
about 10.9:1, about 11:1, about 11.1:1, about 11.2:1, about 11.3:1,
about 11.4:1, about 11.5:1, 11 3.6:1, about 11.7:1, about 11.8:1,
about 11.9:1, about 12:1, about 12.1:1, about 12.2:1, about 12.3:1,
about 12.4:1, about 12.5:1, about 12.6:1, about 12.7:1, about
12.8:1, about 12.9:1, about 13:1, about 13.1:1, about 13.2:1, about
13.3:1, about 13.4:1, about 13.5:1, about 13.6:1, about 13.7:1,
about 13.8:1, about 13.9:1, about 14:1, or greater. In an exemplary
embodiment, the compressor 102 may include a plurality of
compressor stages, where a first stage (not shown) of the plurality
of compressor stages may have a compression ratio of about 1.75:1
and a second stage (not shown) of the plurality of compressor
stages may have a compression ratio of about 6.0:1.
[0023] FIG. 2 illustrates a cross-sectional view of an embodiment
of the compressor 102, which may be included in the compression
system 100 of FIG. 1. As shown in FIG. 2, the compressor 102
includes a housing 110 forming or having an axial inlet 112
defining an inlet passageway 114, a static diffuser 116 fluidly
coupled to the inlet passageway 114, and a collector 117 fluidly
coupled to the static diffuser 116. Although illustrated as an
axial inlet in FIG. 2, in one or more other embodiments, the inlet
112 may be a radial inlet. The driver 104 may be disposed outside
of (as shown in FIG. 1) or within the housing 110, such that the
housing 110 may have a first end, or compressor end, and a second
end (not shown), or driver end. The housing 110 may be configured
to hermetically seal the driver 104 and the compressor 102 within,
thereby providing both support and protection to each component of
the compression system 100. The housing 110 may also be configured
to contain the process fluid flowing through one or more portions
or components of the compressor 102.
[0024] The drive shaft 106 of the driver 104 and the rotary shaft
108 of the compressor 102 may be supported, respectively, by one or
more radial bearings 118, as shown in FIG. 1 in an overhung
configuration. The radial bearings 118 may be directly or
indirectly supported by the housing 110, and in turn provide
support to the drive shaft 106 and the rotary shaft 108, which
carry the compressor 102 and the driver 104 during operation of the
compression system 100. In one embodiment, the radial bearings 118
may be magnetic bearings, such as active or passive magnetic
bearings. In other embodiments, however, other types of bearings
(e.g., oil film bearings) may be used. In addition, at least one
axial thrust bearing 120 may be provided to manage movement of the
rotary shaft 108 in the axial direction. In an embodiment in which
the driver 104 and the compressor 102 are hermetically-sealed
within the housing 110, the thrust bearing 120 may be provided at
or near the end of the rotary shaft 108 adjacent the compressor end
of the housing 110. The axial thrust bearing 120 may be a magnetic
bearing and may be configured to bear axial thrusts generated by
the compressor 102.
[0025] As shown in FIG. 2, the axial inlet 112 defining the inlet
passageway 114 of the compressor 102 may include one or more inlet
guide vanes 122 of an inlet guide vane assembly configured to
condition a process fluid flowing therethrough to achieve
predetermined or desired fluid properties and/or fluid flow
attributes. Such fluid properties may include flow pattern (e.g.,
swirl distribution), velocity, mass flow rate, pressure,
temperature, and/or any suitable fluid property and fluid flow
attribute to enable the compressor 102 to function as described
herein. The inlet guide vanes 122 may be disposed within the inlet
passageway 114 and may be static or moveable, i.e., adjustable. In
an exemplary embodiment, a plurality of inlet guide vanes 122 may
be arranged about a circumferential inner surface 124 of the axial
inlet 112 in a spaced apart orientation, each extending into the
inlet passageway 114. The spacing of the inlet guide vanes 122 may
be equidistant or may vary depending on the predetermined process
fluid property and/or fluid flow attribute desired. With reference
to shape, the inlet guide vanes 122 may be airfoil shaped,
streamline shaped, or otherwise shaped and configured to at least
partially impart the one or more fluid properties and/or fluid flow
attributes on the process fluid flowing through the inlet
passageway 114.
[0026] In one or more embodiments, the inlet guide vanes 122 may be
moveably coupled to the housing 110 and disposed within the inlet
passageway 114 as disclosed in U.S. Pat. No. 8,632,302, the subject
matter of which is incorporated by reference herein to the extent
consistent with the present disclosure. The inlet guide vanes 122
may be further coupled to an annular inlet guide vane actuation
member (not shown), such that upon actuation of the annular inlet
vane actuation member, each of the inlet guide vanes 122 coupled to
the annular inlet guide vane actuation member may pivot about the
respective coupling to the housing 110, thereby adjusting the flow
incident on components of the compressor 102. As configured, the
inlet guide vanes 122 may be adjusted without disassembling the
housing 110 in order to adjust the performance of the compressor
102. Doing so without disassembly of the compressor 102 saves time
and effort in optimizing the compressor 102 for a particular
operating condition. Furthermore, the impact of alternate vane
angles on overall flow range and/or peak efficiency may be assessed
and optimized for increased performance, and a matrix of inlet
guide vane angles may be produced on a relatively short cycle time
relative to conventional compressors such that the data may be
analyzed to determine the best combination of inlet guide vane
angles for any given application.
[0027] The compressor 102 may include a centrifugal impeller 126
configured to rotate about a center axis 128 within the housing
110. In an exemplary embodiment, the centrifugal impeller 126
includes a hub 130 and is open or "unshrouded." In another
embodiment, the centrifugal impeller 126 may be a shrouded
impeller. The hub 130 may include a first meridional end portion
132, generally referred to as the eye of the centrifugal impeller
126, and a second meridional end portion 134 having a disc shape,
the outer perimeter of the second meridional end portion 134
generally referred to as the tip 136 of the centrifugal impeller
126. The disc-shaped, second meridional end portion 134 may taper
inwardly to the first meridional end portion 132 having an annular
shape. The hub 130 may define a bore 138 configured to receive a
coupling member 140, such as a tie-bolt, to couple the centrifugal
impeller 126 to the rotary shaft 108. In another embodiment, the
bore 138 may be configured to receive the rotary shaft 108
extending therethrough.
[0028] As shown in FIG. 2, the compressor 102 may include a balance
piston 142 configured to balance an axial thrust generated by the
centrifugal impeller 126 during operation. In an exemplary
embodiment, the balance piston 142 may be integral with the
centrifugal impeller 126, such that the balance piston 142 and the
centrifugal impeller 126 are formed from a single or unitary piece.
In another embodiment, the balance piston 142 and the centrifugal
impeller 126 may be separate components. For example, the balance
piston 142 and the centrifugal impeller 126 may be separate annular
components coupled with one another. One or more seals, e.g.,
labyrinth seals, may be implemented to isolate the balance piston
142 from external contaminants or lubricants.
[0029] The centrifugal impeller 126 may be operatively coupled to
the rotary shaft 108 such that the rotary shaft 108, when acted
upon by the driver 104 via the drive shaft 106, rotates, thereby
causing the centrifugal impeller 126 to rotate such that process
fluid flowing into the inlet passageway 114 is drawn into the
centrifugal impeller 126 and accelerated to the tip 136, or
periphery, of the centrifugal impeller 126, thereby increasing the
velocity of the process fluid. In one or more embodiments, the
process fluid at the tip 136 of the centrifugal impeller 126 may be
subsonic and have an absolute Mach number less than one. For
example, the process fluid at the tip 136 of the centrifugal
impeller 126 may have an exit absolute Mach number less than one,
less than 0.9, less than 0.8, less than 0.7, less than 0.6, or less
than 0.5. Accordingly, in such embodiments, the compressor 102
discussed herein may be "subsonic," as the centrifugal impeller 126
may be configured to rotate about the center axis 128 at a speed
sufficient to provide the process fluid at the tip 136 thereof with
an exit absolute Mach number of less than one.
[0030] In one or more embodiments, the process fluid at the tip 136
of the centrifugal impeller 126 may be supersonic and have an exit
absolute Mach number of one or greater. For example, the process
fluid at the tip 136 of the centrifugal impeller 126 may have an
exit absolute Mach number of at least one, at least 1.1, at least
1.2, at least 1.3, at least 1.4, or at least 1.5. Accordingly, in
such embodiments, the compressor 102 discussed herein may be
"supersonic," as the centrifugal impeller 126 may be configured to
rotate about the center axis 128 at a speed sufficient to provide
the process fluid at the tip 136 thereof with an exit absolute Mach
number of one or greater or with a fluid velocity greater than the
speed of sound. In a supersonic compressor or a stage thereof, the
rotational or tip speed of the centrifugal impeller 126 may be
about 500 meters per second (m/s) or greater. For example, the tip
speed of the centrifugal impeller 126 may be about 510 m/s, about
520 m/s, about 530 m/s, about 540 m/s, about 550 m/s, about 560
m/s, or greater.
[0031] Referring now to FIGS. 3-5, with continued reference to FIG.
2, FIG. 3 illustrates a perspective view of the centrifugal
impeller 126 that may be included in the compressor 102, according
to one or more embodiments. FIG. 4 illustrates a front view of a
portion of the centrifugal impeller 126 of FIG. 3 and a portion of
the static diffuser 116 that may be included in the compressor 102
of FIG. 2, according to one or more embodiments. FIG. 5 illustrates
a front view of a portion of the centrifugal impeller 126 of FIG. 3
and a portion of another static diffuser 216 that may be included
in the compressor 102 of FIG. 2 and utilized in place of the static
supersonic diffuser 116, according to one or more embodiments.
[0032] As shown in FIG. 2 and more clearly in FIGS. 3-5, the
centrifugal impeller 126 may include a plurality of aerodynamic
surfaces or blades 144a,b coupled or integral with the hub 130 and
configured to increase the velocity and energy of the process
fluid. As illustrated in FIGS. 3-5, the blades 144a,b of the
centrifugal impeller 126 may be curved, such that the process fluid
may be urged in a tangential and radial direction by the
centrifugal force through a plurality of flow passages 146, 148
formed by the blades 144a,b and discharged from the blade tips of
the centrifugal impeller 126 (cumulatively, the tip 136 of the
centrifugal impeller 126) in at least partially radial directions
that extend 360 degrees around the centrifugal impeller 126. It
will be appreciated that the contour or amount of curvature of the
blades 144a,b is not limited to the shaping illustrated in FIGS.
3-5 and may be determined based, at least in part, on desired
operating parameters.
[0033] The plurality of blades 144a,b may include main blades 144a
spaced equidistantly apart and circumferentially about the center
axis 128. Each main blade 144a may extend from a leading edge 150
disposed adjacent the first meridional end portion 132 of the
centrifugal impeller 126 to a trailing edge 152 disposed adjacent
the second meridional end portion 134 of the centrifugal impeller
126. Further, based on rotation of the centrifugal impeller 126,
each main blade 144a may define a pressure surface on one side 154
of the main blade 144a and a suction surface on the opposing side
156 of the main blade 144a. As shown most clearly in FIG. 3, the
centrifugal impeller 126 may include thirteen main blades 144a;
however, other embodiments including more than or less than
thirteen main blades are contemplated herein. The number of main
blades 144a may be determined based, at least in part, on desired
operating parameters.
[0034] The plurality of blades 144a,b may also include one or more
splitter blades 144b configured to reduce aerodynamic choking
conditions that may occur in the compressor 102 depending on the
number of blades 144a,b employed with respect to the centrifugal
impeller 126. The splitter blades 144b may be spaced equidistantly
apart and circumferentially about the center axis 128. Each
splitter blade 144b may extend from a leading edge 158,
meridionally spaced and downstream from the first meridional end
portion 132, to a trailing edge 160 disposed adjacent the second
meridional end portion 134 of the centrifugal impeller 126. The
leading edge 158 of each splitter blade 144b may be disposed
meridionally outward from the leading edges 150 of the main blades
144a such that the respective leading edges 150, 158 of the main
blades 144a and splitter blades 144b are staggered and not
coplanar. Further, based on rotation of the centrifugal impeller
126, each splitter blade 144b may define a pressure surface on one
side 162 of the splitter blade 144b and a suction surface on the
opposing side 164 of the splitter blade 144b.
[0035] As most clearly illustrated in FIGS. 2 and 3, each of the
main blades 144a and the splitter blades 144b extends meridionally
from the second meridional end portion 134 of the centrifugal
impeller 126 toward the first meridional end portion 132 thereof.
The configuration of the respective meridional extents of the main
blades 144a and the splitter blades 144b may be substantially
similar proximal the respective trailing edges 152, 160 of the main
blades 144a and the splitter blades 144b. The configuration of the
respective meridional extents of the main blades 144a and the
splitter blades 144b may differ from the second meridional end
portion 134 to the respective leading edges 150, 158 of the main
blades 144a and the splitter blades 144b. In an exemplary
embodiment, the meridional extent of each of the main blades 144a
may be greater than the meridional extent of each of the splitter
blades 144b, such that the respective leading edges 158 of the
splitter blades 144b may be disposed meridionally offset toward the
second meridional end portion 134 of the centrifugal impeller 126
from the respective leading edges 150 of the main blades 144a.
[0036] The splitter blades 144b and main blades 144a may be
arranged circumferentially about the center axis 128 in a pattern
such that a splitter blade 144b is disposed between adjacent main
blades 144a. As arranged, each splitter blade 144b may be disposed
between the pressure surface side 154 of an adjacent main blade
144a and the suction surface side 156 of the other adjacent main
blade 144a. Further, the splitter blades 144b may be "clocked" with
respect to the main blades 144a, such that each splitter blade 144b
is circumferentially offset or not equidistant from the respective
adjacent main blades 144a and thus is not circumferentially
centered between the adjacent main blades 144a. By clocking the
splitter blades 144b, e.g., displacing the splitter blades 144b
from a position equidistant from adjacent main blades 144a, the
operating characteristics of the centrifugal impeller 126 may be
improved.
[0037] In one or more embodiments, the splitter blades 144b and
main blades 144a may be arranged circumferentially about the center
axis 128 in a pattern such that a plurality of splitter blades 144b
may be disposed between adjacent main blades 144a. Accordingly, in
one embodiment, at least two splitter blades 144b are disposed
between adjacent main blades 144a. The leading edges 158 of the
respective splitter blades 144b may be offset meridionally from one
another such that the respective leading edges 158 of the splitter
blades 144b are staggered and not coplanar.
[0038] As positioned between the adjacent main blades 144a, each
splitter blade 144b may be oriented such that the splitter blade
144b is canted, such that the leading edge 158 of the splitter
blade 144b is circumferentially offset from a position equidistant
from the adjacent main blades 144a a different percentage amount
than the trailing edge 160 of the splitter blade 144b. Accordingly,
in an exemplary embodiment, the leading edge 158 of the splitter
blade 144b may be displaced from a position equidistant from the
adjacent main blades 144a by a distance of a first percentage
amount of one half the angular distance .theta. between the
adjacent main blades 144a. The trailing edge 160 of the splitter
blade 144b may be displaced from the position equidistant the
adjacent main blades 144a by a distance of a second percentage
amount of one half the angular distance 8 between the adjacent main
blades 144a.
[0039] In an exemplary embodiment, the first percentage amount may
be greater than the second percentage amount. In another
embodiment, the first percentage amount may be less than the second
percentage amount. For example, the difference in displacement
between the leading edge 158 and the trailing edge 160 from the
position equidistant the adjacent main blades 144a may be a
percentage amount of about one percent, about two percent, about
three percent, about four percent, about five percent, about ten
percent, about fifteen percent, about twenty percent, or greater.
In another example, the difference in displacement between the
leading edge 158 and the trailing edge 160 from the position
equidistant the adjacent main blades 144a may be a percentage
amount of between about one percent and about two percent, about
three percent and about five percent, about five percent and about
ten percent, or about ten percent and about twenty percent. The
differences in distance related to the percentage amounts, e.g.,
the amount the splitter blade 144b is canted, may be determined
based, at least in part, on desired operating parameters.
[0040] As shown in FIGS. 3-5, a plurality of flow passages 146, 148
may be formed between the splitter blades 144b and the adjacent
main blades 144a as arranged about the center axis 128. In an
exemplary embodiment, the plurality of flow passages 146, 148 may
include a first flow passage 146 formed between the pressure
surface side 162 of the splitter blade 144b and the suction surface
side 156 of one of the adjacent main blades 144a and a second flow
passage 148 between the suction surface side 164 of the splitter
blade 144b and the pressure surface side 154 of the other adjacent
main blade 144a. The mass flow of the process fluid through the
first and second flow passages 146, 148 may be determined based on
the displacement of the splitter blade 144b in relation to the
adjacent main blades 144b. For example, it has been determined that
disposing the splitter blade 144b equidistantly between the
adjacent main blades 144a may not result in equal mass flow through
the first flow passage 146 and the second flow passage 148.
Accordingly, in an exemplary embodiment, the splitter blade 144b
may be circumferentially offset from a position centered between
adjacent main blades 144a, such that the suction surface side 164
of the splitter blade 144b is disposed in a direction closer to the
pressure surface side 154 of one of the adjacent main blades 144a
and further from the suction surface side 156 of the other adjacent
main blade 144a, thereby substantially equalizing the mass flow
through the respective flow passages 146, 148.
[0041] As will be appreciated by those of skill in the art, the
desired displacement of the splitter blades 144b may depend on
various factors, such as the shape of the blades 144a,b, the angle
of incidence of the blades 144a,b, the size of the blades 144a,b
and of the centrifugal impeller 126, the operating speed range,
etc. However, the displacement necessary to equalize the mass flow
through the first flow passage 146 and the second flow passage 148
may be determined for a given design of the centrifugal impeller
126 and corresponding blades 144a,b by measurement of the mass
flow, such as by use of a mass flow meter.
[0042] As shown in FIG. 2, the compressor 102 may include a shroud
170 coupled to the housing 110 and disposed adjacent the plurality
of blades 144a,b of the centrifugal impeller 126. In particular, a
surface 172 of the shroud 170 may include an abradable material and
may be contoured to substantially align with the silhouette of the
plurality of blades 144a,b, thus substantially reducing leakage
flow of the process fluid in a gap defined therebetween. The
abradable material is arranged on the surface 172 of the shroud 170
and configured to be deformed and/or removed therefrom during
incidental contact of the rotating centrifugal impeller 126 with
the abradable material of the stationary shroud 170 during axial
movement of the rotary shaft 108, thereby preventing damage to the
blades 144a,b and resulting in a loss of a sacrificial amount of
the abradable material.
[0043] In an embodiment, illustrated most clearly in FIG. 4 with
continued reference to FIG. 2, the compressor 102 may include the
static diffuser 116 fluidly coupled to the axial inlet 112 and
configured to receive the radial process fluid flow exiting the tip
136 of the centrifugal impeller 126. In an exemplary embodiment,
the static diffuser 116 may be a vaneless diffuser. The static
diffuser 116 may be configured to convert kinetic energy of the
process fluid from the centrifugal impeller 126 into increased
static pressure. In an exemplary embodiment, the static diffuser
116 may be located downstream of the centrifugal impeller 126 and
may be statically disposed circumferentially about the periphery,
or tip 136, of the centrifugal impeller 126.
[0044] The static diffuser 116 may be coupled with or integral with
the housing 110 of the compressor 102 and may form an annular
diffuser passageway 174 having an inlet end 176 adjacent the tip
136 of the centrifugal impeller 126 and a radially outer outlet end
178. In an exemplary embodiment, the annular diffuser passageway
174 may be formed, at least in part, by portions of the housing
110, namely a shroud wall 180 and a hub wall 182, forming the
confining sidewalls of the static diffuser 116. The shroud wall 180
and the hub wall 182 may each be a straight wall or a contoured
wall, such that the annular diffuser passageway 174 may be formed
from straight walls, contoured walls, or a combination thereof. In
addition, the annular diffuser passageway 174 may have a reduced
width as the shroud wall 180 and the hub wall 182 extend radially
outward. Such a "pinched" diffuser may provide for lower choke and
surge limits and, thus, improve the efficiency of the centrifugal
impeller 126.
[0045] In another embodiment, illustrated most clearly in FIG. 5
with continued reference to FIG. 2, a static diffuser 216 may be
utilized in the compressor 102 in place of the static diffuser 116
disclosed above. The static diffuser 216 illustrated in FIG. 5 may
be similar in some respects to the static diffuser 116 described
above and therefore may be best understood with reference to the
description of FIGS. 2 and 4, where like numerals may designate
like components and will not be described again in detail. The
static diffuser 216 may be fluidly coupled to the axial inlet 112
and configured to receive the radial process fluid flow exiting the
centrifugal impeller 126.
[0046] The static diffuser 216 may be configured to convert kinetic
energy of the process fluid from the centrifugal impeller 126 into
increased static pressure. In an exemplary embodiment, the static
diffuser 216 may be located downstream of the centrifugal impeller
126 and may be statically disposed circumferentially about the
periphery, or tip 136, of the centrifugal impeller 126. The static
diffuser 216 may be coupled with or integral with the housing 110
of the compressor 102 and may further form the annular diffuser
passageway 174 having the inlet end 176 adjacent the tip 136 of the
centrifugal impeller 126 and the radially outer outlet end 178. In
an exemplary embodiment, the annular diffuser passageway 174 may be
formed, at least in part, by the shroud wall 180 and the hub wall
182 of the housing 110.
[0047] In an exemplary embodiment, the static diffuser 216 may be a
vaned diffuser, e.g., wedge diffuser, or a vaned diffuser as shown
in FIG. 5. The static diffuser 216 may have a plurality of diffuser
vanes 184, 186 arranged in a plurality of concentric rings 188, 190
about the center axis 128 and extending from the shroud wall 180 or
the hub wall 182 or from both the shroud wall 180 and the hub wall
182 of the static diffuser 216. As shown in FIG. 5, the plurality
of diffuser vanes 184, 186 may include first row vanes 184 arranged
in a first ring 188 about the center axis 128 and extending from
the hub wall 182 of the static diffuser 216. The first row vanes
184 each include a leading edge 192 disposed proximal the inlet end
176 and a trailing edge 194 radially and circumferentially offset
from the leading edge 192. The first row vanes 184 may be low
solidity diffuser vanes, where the chord to pitch ratio of the
first row vanes 184 is less than one. As provided herein, diffuser
vanes having a chord to pitch ratio of less than one are referred
to as low solidity diffuser vanes. In the illustrated embodiment of
FIG. 5, the first ring 188 includes seventeen low solidity diffuser
vanes; however, embodiments including more or less than seventeen
low solidity diffuser vanes are contemplated herein. Each of the
first row vanes 184 may be airfoils or shaped substantially similar
thereto.
[0048] As shown in FIG. 5, the plurality of diffuser vanes 184, 186
may include second row vanes 186 arranged in a second ring 190
about the center axis 128 and extending from the hub wall 182 of
the static diffuser 216. The plurality of diffuser vanes 184, 186
is arranged in tandem, such that the second ring 190 of second row
vanes 186 is disposed radially outward from the first ring 188 of
first row vanes 184. The second row vanes 186 include respective
leading edges 196 disposed proximal the trailing edges 194 of the
first row vanes 184 and respective trailing edges 198 radially and
circumferentially offset from the leading edges 196. The second row
vanes 186 may have a greater solidity than the first row vanes 184,
where the chord to pitch ratio of the second row vanes 186 is
generally greater than the chord to pitch ratio of the first row
vanes 184. In an exemplary embodiment, the chord to pitch ratio of
the second row vanes 186 is one or greater. As provided herein,
diffuser vanes having a chord to pitch ratio of one or greater are
referred to as high solidity diffuser vanes. In the illustrated
embodiment of FIG. 5, the second ring 190 includes a multiple of
the number of first row vanes 184, and more specifically, twice the
number of first row vanes 184. Thus, in an embodiment in which the
first ring 188 includes seventeen first row vanes 184, the second
ring 190 may include thirty-four diffuser vanes; however,
embodiments including more or less than thirty-four diffuser vanes
are contemplated herein. Each of the second row vanes 186 may be
airfoils or shaped substantially similar thereto.
[0049] In an exemplary embodiment, the first row vanes 184 of the
first ring 188 may be proximal the tip 136 of the centrifugal
impeller 126 and may be spaced therefrom via an inner vaneless
space 200. Accordingly, the inner vaneless space 200 may be
provided between the centrifugal impeller tip diameter 202 and the
leading edge diameter 204 of the first ring 188. In an exemplary
embodiment, the inner vaneless space 200 may be formed from the
leading edge diameter 204 being about five to about ten percent
greater than the centrifugal impeller tip diameter 202. In another
embodiment, the inner vaneless space 200 may be formed from the
leading edge diameter 204 being about six to about eight percent
greater than the centrifugal impeller tip diameter 202. Similarly,
an outer vaneless space 206 may be provided between the diameter
208 formed by the trailing edges 194 of the first row vanes 184 of
the first ring 188 and the diameter 210 of the leading edges 196 of
the second row vanes 186 of the second ring 190. In an exemplary
embodiment, the outer vaneless space 206 may be formed from the
leading edge diameter 210 of the second ring 190 being about five
to about ten percent greater than the trailing edge diameter 208 of
the first ring 188. In another embodiment, the outer vaneless space
206 may be formed from the leading edge diameter 210 of the second
ring 190 being about six to about eight percent greater than the
trailing edge diameter 208 of the first ring 188.
[0050] In an exemplary embodiment, the incidence of the first row
vanes 184 of the first ring 188 may be determined for controlling
the exit absolute Mach number and reducing supersonic flow
introduced at the inlet end 176 of the static diffuser 216 to a
subsonic flow at the trailing edges 194 of the first ring 188. As
configured, shock waves created by the leading edges 192 of the
first ring 188 do not propagate to the second row vanes 186;
however, the leading edges 192 of the first ring 188 provide for a
communication path from the downstream portion of the static
diffuser 216 toward an upstream portion of the centrifugal impeller
126 to back pressure the centrifugal impeller 126, thereby
obtaining a wider range. The incidence of the second row vanes 186
of the second ring 190 may be determined by placing the second ring
190 in the "shadow" or flow path of the first ring 188.
Accordingly, the second row vanes 186 may be arranged such that two
second row vanes 186 are provided in the wake of each first row
vane 184 and are provided to alter the direction of the process
fluid flow.
[0051] In another embodiment, the static diffuser 216 may include
third row vanes (not shown) arranged in a third ring (not shown)
about the center axis 128 and disposed radially outward of the
first ring 188 and the second ring 190, where the first ring 188,
the second ring 190, and the third ring are concentric. The third
row vanes may have a chord to pitch ratio less than the chord to
pitch ratio of the second row vanes 186 of the second ring 190. In
another embodiment, the third row vanes may have a chord to pitch
ratio substantially equal to the chord to pitch ratio of the first
row vanes 184 of the first ring 188. The third row vanes may be
configured to provide additional turning of the process fluid
flow.
[0052] As discussed above, in one or more embodiments, the
compressor 102 provided herein may be referred to as "supersonic"
because the centrifugal impeller 126 may be designed to rotate
about the center axis 128 at high speeds such that a moving process
fluid encountering the inlet end 176 of the static diffuser 116 is
said to have a fluid velocity which is above the speed of sound of
the process fluid being compressed. Thus, in an exemplary
embodiment, the moving process fluid encountering the inlet end 176
of the static diffuser 116 may have an exit absolute Mach number of
about one or greater. However, to increase total energy of the
fluid system, the moving process fluid encountering the inlet end
176 of the static diffuser 116 may have an exit absolute Mach
number of at least about 1.1, at least about 1.2, at least about
1.3, at least about 1.4, or at least about 1.5. In another example,
the process fluid at the tip 136 of the centrifugal impeller 126
may have an exit absolute Mach number from about 1.1 to about 1.5,
or about 1.2 to about 1.4.
[0053] The process fluid flow leaving the outlet end 178 of the
static diffuser 116, 216 may flow into the collector 117, as most
clearly seen in FIG. 2. The collector 117 may be configured to
gather the process fluid flow from the static diffuser 116, 216 and
to deliver the process fluid flow to a downstream pipe and/or
process component (not shown). In an exemplary embodiment, the
collector 117 may be a discharge volute or specifically, a
scroll-type discharge volute. In another embodiment, the collector
117 may be a plenum. The collector 117 may be further configured to
increase the static pressure of the process fluid flow by
converting the kinetic energy of the process fluid to static
pressure. The collector 117 may have a round tongue (not shown). In
another embodiment, the collector may have a sharp tongue (not
shown). It will be appreciated that the tongue of the collector 117
may form other shapes known to those of ordinary skill in the art
without varying from the scope of this disclosure.
[0054] One or more exemplary operational aspects of an exemplary
compression system 100 will now be discussed with continued
reference to FIGS. 1-5. A process fluid may be provided from an
external source (not shown), having a low pressure environment, to
the compression system 100. The compression system 100 may include,
amongst other components, the compressor 102 having the centrifugal
impeller 126 coupled with the rotary shaft 108 and the static
diffuser 116 disposed circumferentially about the rotating
centrifugal impeller 126. In another embodiment, the compression
system 100 may include, amongst other components, the compressor
102 having the centrifugal impeller 126 coupled with the rotary
shaft 108 and the static diffuser 216 disposed circumferentially
about the rotating centrifugal impeller 126.
[0055] The process fluid may be drawn into the axial inlet 112 of
the compressor 102 with a velocity ranging, for example, from about
Mach 0.05 to about Mach 0.40. The process fluid may flow through
the inlet passageway 114 defined by the axial inlet 112 and across
the inlet guide vanes 122 extending into the inlet passageway 114.
The process fluid flowing across the inlet guide vanes 122 may be
provided with an increased velocity and imparted with at least one
fluid property (e.g., swirl) prior to be being drawn into the
rotating centrifugal impeller 126. The inlet guide vanes 122 may be
adjusted in order to vary the one or more fluid properties imparted
to the process fluid.
[0056] The process fluid may be drawn into the rotating centrifugal
impeller 126 and may contact the curved centrifugal impeller blades
144a,b, such that the process fluid may be accelerated in a
tangential and radial direction by centrifugal force and may be
discharged from the flow passages 146, 148 via the blade tips of
the centrifugal impeller 126 (cumulatively, the tip 136 of the
centrifugal impeller 126) in at least partially radial directions
that extend 360 degrees around the rotating centrifugal impeller
126. The rotating centrifugal impeller 126 increases the velocity
and static pressure of the process fluid, such that the velocity of
the process fluid discharged from the blade tips (cumulatively, the
tip 136 of the centrifugal impeller 126) may be supersonic in some
embodiments and have an exit absolute Mach number of at least about
one, at least about 1.1, at least about 1.2, at least about 1.3, at
least about 1.4, or at least about 1.5.
[0057] In an embodiment, the static diffuser 116 may be disposed
circumferentially about the periphery, or tip 136, of the
centrifugal impeller 126 and may be coupled with or integral with
the housing 110 of the compressor 102. In another embodiment, the
static diffuser 216 may be disposed circumferentially about the
periphery, or tip 136, of the centrifugal impeller 126 and may be
coupled with or integral with the housing 110 of the compressor
102. The radial process fluid flow discharged from the rotating
centrifugal impeller 126 may be received by the static diffuser
116, 216 such that the velocity of the flow of process fluid
discharged from the tip 136 of the rotating centrifugal impeller
126 is substantially similar to the velocity of the process fluid
entering the inlet end 176 of the static diffuser 116, 216.
Accordingly, the process fluid may enter the inlet end 176 of the
static diffuser 116, 216 with a supersonic velocity having, for
example, an exit absolute Mach number of at least one, and
correspondingly, may be referred to as supersonic process
fluid.
[0058] The velocity of the supersonic process fluid flowing into
the inlet end 176 of the static diffuser 116, 216 decreases with
increasing radius of the annular diffuser passageway 174 as the
process fluid flows from the inlet end 176 to the radially outer
outlet end 178 of the static diffuser 116, 216 as the velocity head
is converted to static pressure. In at least one embodiment
including the static diffuser 216, the tangential velocity of the
supersonic process fluid may decelerate from supersonic to subsonic
velocities across the first row vanes 184 without shock losses. The
static diffuser 116, 216 may reduce the velocity and increase the
pressure energy of the process fluid.
[0059] The process fluid exiting the static diffuser 116, 216 may
have a subsonic velocity and may be fed into the collector 117 or
discharge volute. The collector 117 may increase the static
pressure of the process fluid by converting the remaining kinetic
energy of the process fluid to static pressure. The process fluid
may then be routed to perform work or for operation of one or more
downstream processes or components (not shown).
[0060] The process fluid pressurized, circulated, contained, or
otherwise utilized in the compression system 100 may be a fluid in
a liquid phase, a gas phase, a supercritical state, a subcritical
state, or any combination thereof. The process fluid may be a
mixture, or process fluid mixture. The process fluid may include
one or more high molecular weight process fluids, one or more low
molecular weight process fluids, or any mixture or combination
thereof. As used herein, the term "high molecular weight process
fluids" refers to process fluids having a molecular weight of about
30 grams per mole (g/mol) or greater. Illustrative high molecular
weight process fluids may include, but are not limited to,
hydrocarbons, such as ethane, propane, butanes, pentanes, and
hexanes. Illustrative high molecular weight process fluids may also
include, but are not limited to, carbon dioxide (CO.sub.2) or
process fluid mixtures containing carbon dioxide. As used herein,
the term "low molecular weight process fluids" refers to process
fluids having a molecular weight less than about 30 g/mol.
Illustrative low molecular weight process fluids may include, but
are not limited to, air, hydrogen, methane, or any combination or
mixtures thereof.
[0061] In an exemplary embodiment, the process fluid or the process
fluid mixture may be or include carbon dioxide. The amount of
carbon dioxide in the process fluid or the process fluid mixture
may be at least about 80%, at least about 85%, at least about 90%,
at least about 95%, at least about 96%, at least about 97%, at
least about 98%, at least about 99%, or greater by volume.
Utilizing carbon dioxide as the process fluid or as a component or
part of the process fluid mixture in the compression system 100 may
provide one or more advantages. For example, the high density and
high heat capacity or volumetric heat capacity of carbon dioxide
with respect to other process fluids may make carbon dioxide more
"energy dense." Accordingly, a relative size of the compression
system 100 and/or the components thereof may be reduced without
reducing the performance of the compression system 100.
[0062] The carbon dioxide may be of any particular type, source,
purity, or grade. For example, industrial grade carbon dioxide may
be utilized as the process fluid without departing from the scope
of the disclosure. Further, as previously discussed, the process
fluids may be a mixture, or process fluid mixture. The process
fluid mixture may be selected for one or more desirable properties
of the process fluid mixture within the compression system 100. For
example, the process fluid mixture may include a mixture of a
liquid absorbent and carbon dioxide (or a process fluid containing
carbon dioxide) that may enable the process fluid mixture to be
compressed to a relatively higher pressure with less energy input
than compressing carbon dioxide (or a process fluid containing
carbon dioxide) alone.
[0063] FIG. 6 is a flowchart depicting an exemplary method 300 for
compressing a process fluid, according to one or more embodiments.
The method 300 may include driving a rotary shaft of a supersonic
compressor via a driver operatively coupled with the supersonic
compressor, as at 302. The drive shaft may be driven by a driver,
such as, for example, an electric motor.
[0064] The method 300 may also include establishing a fluid
property of the process fluid flowing through an inlet passageway
defined by an inlet of the supersonic compressor via at least one
moveable inlet guide vane pivotally coupled to a housing of the
supersonic compressor and extending into the inlet passageway, the
process fluid including carbon dioxide, as at 304. The method may
also include adjusting the at least one moveable inlet guide vane
to establish the fluid property of the process fluid, where the
fluid property is a flow pattern, a first velocity, a mass flow
rate, a pressure, or a temperature.
[0065] The method 300 may further include rotating a centrifugal
impeller mounted about the rotary shaft, such that the process
fluid flowing though the inlet passageway of the supersonic
compressor is drawn into the centrifugal impeller and discharged
from a tip of the centrifugal impeller via a plurality of flow
passages, the discharged process fluid having a supersonic velocity
with an exit absolute Mach number of about one or greater, as at
306. The method 300 may also include flowing the discharged process
fluid having a supersonic velocity through an annular diffuser
passageway defined by a static diffuser and fluidly coupled to the
plurality of flow passages such that a pressure energy of the
discharged process fluid is increased, thereby compressing the
discharged process fluid at a compression ratio of about 8:1 or
greater, as at 308.
[0066] The static diffuser may be a vaneless diffuser bounded in
part by a shroud wall and a hub wall defining the annular diffuser
passageway therebetween. The shroud wall bounding the annular
diffuser passageway may be a straight wall, a contoured wall, or a
combination thereof, and the hub wall bounding the annular diffuser
passageway may be a straight wall, a contoured wall, or a
combination thereof. In another embodiment, the static diffuser may
be a vaned diffuser bounded in part by a shroud wall and a hub wall
defining the annular diffuser passageway therebetween, and the
vaned diffuser may include a plurality of low solidity diffuser
vanes extending into the annular diffuser passageway from either or
both the shroud wall and the hub wall.
[0067] It should be appreciated that all numerical values and
ranges disclosed herein are approximate valves and ranges, whether
"about" is used in conjunction therewith. It should also be
appreciated that the term "about," as used herein, in conjunction
with a numeral refers to a value that is +/-5% (inclusive) of that
numeral, +/-10% (inclusive) of that numeral, or +/-15% (inclusive)
of that numeral. It should further be appreciated that when a
numerical range is disclosed herein, any numerical value falling
within the range is also specifically disclosed.
[0068] Certain embodiments and features have been described using a
set of numerical upper limits and a set of numerical lower limits.
It should be appreciated that ranges including the combination of
any two values, e.g., the combination of any lower value with any
upper value, the combination of any two lower values, and/or the
combination of any two upper values are contemplated unless
otherwise indicated.
[0069] The foregoing has outlined features of several embodiments
so that those skilled in the art may better understand the present
disclosure. 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.
* * * * *