U.S. patent application number 11/353413 was filed with the patent office on 2007-08-16 for compressor cooling system.
This patent application is currently assigned to Ingersoll-Rand Company. Invention is credited to James C. Collins, Robert K. Haseley, Vipul R. Mistry.
Application Number | 20070186581 11/353413 |
Document ID | / |
Family ID | 38162157 |
Filed Date | 2007-08-16 |
United States Patent
Application |
20070186581 |
Kind Code |
A1 |
Mistry; Vipul R. ; et
al. |
August 16, 2007 |
Compressor cooling system
Abstract
A compressor system that includes a compressor, a refrigeration
system, a drive member and a cooling passage. The compressor is
operable to produce a flow of compressed fluid. The refrigeration
system includes an evaporator, and a flow of refrigerant passes
through the evaporator and is operable to cool the flow of
compressed fluid. The drive member is coupled to the compressor and
is operable to drive the compressor. The cooling passage extends
from a point downstream of the evaporator to a point upstream of
the compressor. At least a portion of the cooling passage is in
thermal exchange relationship with the drive member.
Inventors: |
Mistry; Vipul R.;
(Charlotte, NC) ; Collins; James C.; (Mooresville,
NC) ; Haseley; Robert K.; (Mooresville, NC) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH, LLP
100 E WISCONSIN AVENUE
Suite 3300
MILWAUKEE
WI
53202
US
|
Assignee: |
Ingersoll-Rand Company
Montvale
NJ
|
Family ID: |
38162157 |
Appl. No.: |
11/353413 |
Filed: |
February 14, 2006 |
Current U.S.
Class: |
62/505 |
Current CPC
Class: |
F04B 39/06 20130101;
F04C 29/0007 20130101; F25B 49/025 20130101; F25B 31/006 20130101;
F25B 5/00 20130101; F04C 18/16 20130101; F25B 2400/075
20130101 |
Class at
Publication: |
062/505 |
International
Class: |
F25B 31/00 20060101
F25B031/00 |
Claims
1. A compressor system comprising: a compressor operable to produce
a flow of compressed fluid; a refrigeration system including an
evaporator, the evaporator passing a flow of refrigerant
therethrough and operable to cool the flow of compressed fluid; a
drive member coupled to the compressor and operable to drive the
compressor; and a cooling passage extending from a point downstream
of the evaporator to a point upstream of the compressor, at least a
portion of the cooling passing in thermal exchange relationship
with the drive member.
2. The compressor system of claim 1, wherein the drive member
includes a motor.
3. The compressor system of claim 2, wherein the drive member
includes a variable frequency drive, and wherein at least a portion
of the flow of refrigerant within the cooling passage is operable
to cool at least one of the motor and the variable frequency
drive.
4. The compressor system of claim 1, wherein the compressor
includes an oil cooler, and wherein at least a portion of the flow
of refrigerant within the cooling passage passes through the oil
cooler to cool a flow of oil.
5. The compressor system of claim 1, wherein the compressor
includes a control system, and wherein at least a portion of the
flow of refrigerant within the cooling passage is operable to cool
the control system.
6. The compressor system of claim 1, further comprising a heat
exchanger positioned within the cooling passage, at least a portion
of the flow of refrigerant within the cooling passage passing
through the heat exchanger to cool the drive member.
7. A method of operating a fluid compression system, the method
comprising: coupling a compressor to a drive member; operating the
drive member to produce a corresponding operation of the compressor
to produce a flow of compressed fluid; passing a flow of
refrigerant through an evaporator to cool the flow of compressed
fluid; passing the flow of refrigerant from the evaporator to a
return line; diverting a portion of the flow of refrigerant from
the return line to the drive member to cool the drive member.
8. The method of claim 7, wherein the drive member includes a
motor.
9. The method of claim 7, further comprising directing a portion of
the refrigerant from the return line to an oil cooler to cool a
flow of oil.
10. The method of claim 7, further comprising directing a portion
of the refrigerant from the return line to a variable frequency
drive to cool the variable frequency drive.
11. The method of claim 7, further comprising directing a portion
of the refrigerant from the return line to a control system to cool
the control system.
12. The method of claim 7, further comprising directing a portion
of the compressed fluid from the compressor through the
refrigeration system to cool the flow of compressed fluid.
13. A fluid compression system comprising: a plurality of
compressors operable to provide a flow of compressed fluid; a
plurality of drive members, each drive member associated with one
of the compressors to drive the compressor; a refrigeration system
including a refrigerant compressor operable to compress and
discharge a flow of refrigerant, the flow of refrigerant in thermal
exchange relationship with the flow of compressed fluid such that
the flow of refrigerant cools the flow of compressed fluid; and a
cooling passage positioned to receive a portion of the flow of
refrigerant, at least a portion of the cooling passage positioned
in thermal exchange relationship with at least one of the plurality
of drive members to cool the at least one of the plurality of drive
members.
14. The fluid compression system of claim 13, wherein at least one
of the plurality of drive members includes a motor.
15. The fluid compression system of claim 14, wherein at least one
of the plurality of drive members includes a variable frequency
drive.
16. The fluid compression system of claim 13, further comprising a
control system operable to control the plurality of compressors and
in thermal exchange relationship with at least a portion of the
cooling passage to cool the control system.
17. The fluid compression system of claim 13, wherein at least one
of the plurality of compressors includes an oil cooler in thermal
exchange relationship with at least a portion of the cooling
passage to cool a flow of oil.
18. The fluid compression system of claim 13, further comprising a
heat exchanger positioned within the cooling passage to cool at
least one of the drive members.
19. The fluid compression system of claim 13, wherein the
refrigeration system includes an evaporator having an outlet.
20. The fluid compression system of claim 19, further comprising a
return passage extending from the outlet to the refrigerant
compressor, the cooling passage connected to the return passage to
receive the portion of the flow of refrigerant.
Description
BACKGROUND
[0001] The present invention relates to a cooling system for use in
a compressor system. More particularly, the present invention
relates to a refrigeration system configured to cool components of
a compressor system.
[0002] Compressor assemblies typically include a compressor that is
driven by a drive member to create a flow of compressed fluid. The
process of creating the flow of compressed fluid can produce a
considerable amount of heat. Typically, the flow of compressed
fluid exits the compressor at a high temperature. Therefore, the
flow of compressed fluid is cooled before it is utilized.
Furthermore, the heat generated by the compression process also
raises the temperature of a fluid, such as oil, utilized by the
compressor for lubricating, sealing and cooling. In addition, other
components of the compressor system such as, the drive member, a
variable frequency drive, and a control system can in some
circumstances create undesirable amounts of heat that can damage
these components or shorten their operating lives.
SUMMARY
[0003] In one embodiment, the invention provides a compressor
system that includes a compressor that is operable to produce a
flow of compressed fluid and a refrigeration system that includes
an evaporator. The evaporator passes a flow of refrigerant
therethrough and is operable to cool the flow of compressed fluid.
The compressor system also includes a drive member that is coupled
to the compressor and is operable to drive the compressor. A
cooling passage extends from a point downstream of the evaporator
to a point upstream of the compressor and at least a portion of the
cooling passage is in thermal exchange relationship with the drive
member.
[0004] In another embodiment the invention provides a method of
operating a fluid compression system that includes coupling a
compressor to a drive member and operating the drive member to
produce a corresponding operation of the compressor to produce a
flow of compressed fluid. The method also includes passing a flow
of refrigerant through an evaporator to cool the flow of compressed
fluid and passing the flow of refrigerant from the evaporator into
a return line. A portion of the flow of refrigerant is diverted
from the return line to the drive member to cool the drive
member.
[0005] In yet another embodiment, the invention provides a fluid
compression system that includes a plurality of compressors
operable to provide a flow of compressed fluid and a plurality of
drive members. Each drive member is associated with one of the
compressors and is operable to drive the compressor. The system
also includes a refrigeration system that includes a refrigeration
compressor, operable to compress and discharge a flow of
refrigerant. The flow of refrigerant is in thermal exchange
relationship with the flow of compressed fluid such that the flow
of refrigerant cools the flow of compressed fluid. A cooling
passage is positioned to receive a portion of the flow of
refrigerant. At least a portion of the cooling passage is
positioned in thermal exchange relationship with one of the
plurality of drive members to cool one of the plurality of drive
members.
[0006] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic view of a compressor system embodying
the present invention;
[0008] FIG. 2 is a schematic view of a portion of the compressor
system of FIG. 1; and
[0009] FIG. 3 is a schematic view of another compressor system
embodying the invention.
[0010] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, it is to be understood that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting. The use of "including,"
"comprising," or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items. Unless specified or limited otherwise,
the terms "mounted," "connected,"
[0011] "supported," and "coupled" and variations thereof are used
broadly and encompass both direct and indirect mountings,
connections, supports, and couplings. Further, "connected" and
"coupled" are not restricted to physical or mechanical connections
or couplings.
DETAILED DESCRIPTION
[0012] FIG. 1 schematically illustrates a compressor system 10 that
includes a compressor assembly 12 and a refrigeration system 14.
The illustrated compressor assembly 12 includes a compressor 16, a
drive member 18, a variable frequency drive (VFD) 20 and a control
system 22.
[0013] The compressor 16 can be any suitable compressor design,
such as a rotary screw compressor, a centrifugal compressor, or a
reciprocating compressor. The illustrated compressor 16 includes a
compressor outlet 24 and an after-cooler 26. The compressor outlet
24 is in fluid communication with the compressor 16 and the
after-cooler 26. The compressor 16 also includes an oil cooler 28
and an oil passage 30. The oil passage 30 is in fluid communication
with the compressor 16 and the oil cooler 28. While the illustrated
compressor 16 includes the oil cooler 28 and the after-cooler 26,
in other constructions the compressor 16 may omit one or both of
the oil cooler 28 and the after-cooler 26.
[0014] Furthermore, while the illustrated compressor 16 is a single
stage compressor, in other constructions, the compressor 16 can be
a multi-stage compressor and can include an inter-cooler located
between each stage. The inter-cooler is configured to cool the air
or working fluid compressed by the compressor 16. In this
arrangement, the output of the first compressor stage is directed
to the inlet of the second compressor stage. This arrangement
allows for a greater pressure increase, which may be necessary in
some application.
[0015] Before proceeding, it should be noted that the term
"passage" and "line" as used herein should be interpreted broadly.
Specifically, the terms "passage" and "line" should be interpreted
to include but not limited to, conduits, channels, tubes, pipes,
valves, flanges, hoses, and the like. Thus, a "passage" or "line"
is essentially any structural element that is able to direct fluid
between first and second points.
[0016] Referring to FIG. 1, the drive member 18 is coupled to the
compressor 16, and in one construction, includes a motor, such as a
variable speed motor. In other constructions, the drive member 18
can include other suitable drive members, such as a turbine, an
internal combustion engine, a diesel engine and the like.
[0017] The refrigeration system 14 includes a refrigerant
compressor 32, a condenser 34, an expansion device 36, an
evaporator 38 and a return line 40. As schematically illustrated in
FIG. 1, the refrigerant compressor 32 is fluidly coupled to the
condenser 34. The condenser 34 is fluidly coupled to the expansion
device 36 and the expansion device 36 is fluidly coupled to the
evaporator 38. The evaporator 38 is in thermal exchange
relationship with the compressor outlet 24 downstream of the
after-cooler 26 to cool the air or working fluid compressed by the
compressor 16. The evaporator 38 includes an evaporator outlet 42
that is fluidly coupled to the return line 40. The return line 40
fluidly couples the evaporator outlet 42 to the refrigerant
compressor 32 to return refrigerant to the refrigerant compressor
32 and complete the cycle. While the illustrated refrigeration
system 18 includes a single refrigerant compressor 32, condenser
34, expansion device 36, evaporator 38, and return line 40, in
other constructions, the refrigeration system 18 can include
multiple refrigerant compressors 32, condensers 34, expansion
devices 36, evaporators 38, and return lines 40, as may be desired.
In addition, as one of ordinary skill in the art will realize,
refrigeration systems may include other components not illustrated
in FIG. 1. These additional components include tanks, valves,
sensors, separators, and the like. As such, the refrigeration
system should not be limited to the components illustrated in FIG.
1.
[0018] As illustrated in FIG. 1, the refrigeration system 14
defines a portion of an air dryer system 44. The air dryer system
44 includes the refrigerant compressor 32, the condenser 34, the
expansion device 36 and the evaporator 38. It should be understood
that in other constructions, the air dryer system may not include
the refrigeration system 14 and may include another suitable air
dryer design, such as a desiccant type air dryer. In such a
construction, the refrigeration system 14 would be a separate
system, independent of the air dryer 44. In yet another
construction, the air dryer system 44 can employ a refrigeration
system separate and distinct from the refrigeration system 14.
[0019] With continued reference to FIG. 1, a cooling passage 46 is
in fluid communication with the return line 40 to draw a portion of
the refrigerant from the refrigeration system 14 after the
refrigerant has passed through the evaporator 38. It should be
understood that the cooling passage 46 can connect to the return
line 40 at any point between the evaporator 38 and the refrigerant
compressor 32. In other constructions, the cooling passage 46
connects directly to the evaporator 38 or to another point within
the refrigeration system 14. In preferred constructions, the
cooling passage 46 may include a pipe, a tube, or other
conduit.
[0020] The cooling passage 46 may include a plurality of portions
48 that are in thermal exchange relationship with one or more of
the after-cooler 26, the oil cooler 28, the drive member 18, the
VFD 20, the control system 22, or other components within the
compressor system (e.g., gearbox). Each of the plurality of
portions 48 includes a flow path that directs a portion of
refrigerant to a component to be cooled. In preferred arrangements,
each of the plurality of portions 48 includes a heat exchanger that
allows the flow of refrigerant to cool the component to be cooled
with greater efficiency.
[0021] As schematically illustrated in FIG. 2, in one construction,
one of the plurality of cooling passage portions 48 includes a heat
exchanger 50 configured to allow the flow of refrigerant to cool
the drive member 18. In such a construction, a fan 51 is driven by
the drive member 18 or a separate fan drive member, to move air
across the heat exchanger 50. The air that passes across the heat
exchanger 50 is cooled and then passes across the drive member 18
to cool the drive member 18. In one construction the separate fan
drive member can be an electric motor, and in such a construction,
the motor can be selectively turned off and on to control the
amount of air that moves across the heat exchanger 50 and the drive
member 18. A temperature switch, or other suitable device, can be
used to start and stop the fan drive member when the drive member
18 has reached predetermined temperatures. For example, the
temperature switch can be configured to turn on the fan drive
member when the temperature of the drive member 18 exceeds a
predetermined temperature, and the temperature switch can be
configured to turn off the fan drive member when the temperature of
the drive member 18 falls below a predetermined temperature.
[0022] The heat exchanger 50 and the fan 51 illustrate just one
possible arrangement of a thermal exchange relationship between one
of the cooling passage portions 48 and the drive member 18. It
should be understood that any suitable thermal exchange
relationship between the plurality of cooling passage portions 48
and the after-cooler 26, the oil cooler 28, the drive member 18,
the VFD 20, or the control system 22 can be utilized.
[0023] A valve, or other suitable control device, can be disposed
in the cooling passage 46 or in the return line 40 to provide
selective fluid communication between the evaporator outlet 42 and
the cooling passage 46. In other constructions, a valve may be
disposed in any one of, or each of the plurality of cooling passage
portions 48 to provide selective fluid communication between the
evaporator outlet 42 and the cooling passage portion 48.
[0024] FIG. 3 illustrates an alternative construction in which a
compressor system 10' includes a plurality of compressor assemblies
12' and a refrigeration system 14'. Although three compressor
assemblies 12' are illustrated, it should be understood two
compressor assemblies or four or more compressor assemblies can be
utilized as desired.
[0025] As schematically illustrated in FIG. 3, each of the
compressor assemblies 12' includes a compressor 16'. The
compressors 16' can be any suitable compressor design, such as
rotary screw compressors, centrifugal compressors, reciprocating
compressors, or any combination thereof. The illustrated
compressors 16' each include a compressor outlet 24' that is
fluidly coupled to an outlet header 54. In other constructions, the
compressor outlets 24' may not be fluidly coupled to the common
outlet header 54, and the outlets 24' can remain independent to
their respective compressor 16'.
[0026] A drive member 18', an after-cooler 26', an oil cooler 28',
a VFD 20' and a control system 22' may be associated with each one
of, or all of the plurality of compressors 16'. In another
construction, each of the compressor assemblies 12' may omit one or
more of the after-cooler 26', the oil cooler 28', the VFD 20'
and/or the control system 22'. In these constructions one control
system, a single oil cooler, or a single after-cooler may function
to control the entire compressor system 10', cool all of the system
oil, or cool all of the compressed air (or other fluid) discharged
by the compressors 16'.
[0027] It should be understood that the remainder of the compressor
system 10' illustrated in FIG. 3, including the refrigeration
system 14', is substantially the same as the compressor system 10'
illustrated in FIG. 1. Therefore, similar items have been given
similar reference numbers.
[0028] The operation of the compressor systems 10, 10' of FIGS. 1
and 3 are similar in many ways. Therefore, only the operation of
the compressor system 10 of FIG. 1 will be discussed in detail. In
operation, the drive member 18 drives the compressor 16 to produce
a flow of compressed fluid, typically air. The flow of compressed
fluid exits the compressor 16 and passes to the compressor outlet
24.
[0029] The compressor outlet 24 directs the flow of compressed
fluid to the after-cooler 26 that is configured to cool the flow of
compressed fluid. The flow of compressed fluid exits the
after-cooler 26 and flows to the evaporator 38 that defines a
portion of the air dryer system 44. The evaporator 38 is configured
to further cool the flow of compressed fluid to allow the air dryer
44 to reduce the amount of moisture contained within the flow of
compressed fluid. The flow of compressed fluid exits the evaporator
38 and flows through the remainder of the air dryer 44 before being
passed to equipment that utilizes the flow of compressed fluid.
[0030] The VFD 20 operates to vary the rotational speed (i.e.
revolutions per minute) of the associated drive member 18 in
response to one or more control signals. Changing the rotational
speed of the drive member 18 results in a corresponding change in
the rotational speed of the compressor 16. By varying the
rotational speed of the compressor 16, the volume of compressed
fluid discharged by the compressor 16 can be varied.
[0031] The control system 22 controls the operation of the
compressor assembly 12. For example, the control system 22 may
control the loading and unloading of the compressor 16 or may cycle
the compressor 16 on and off. The control system 22 may also
monitor various operating parameters of the compressor assembly 12,
such as an outlet fluid pressure, an oil temperature, an outlet
fluid temperature, etc. In addition, the control system 22 controls
the VFD 20 to control the rotational speed of the compressor 16 and
the volume of compressed fluid discharged by the compressor 16.
[0032] A flow of oil is utilized by the compressor 16 to lubricate
and cool components of the compressor 16, such as screw rotors and
bearings. During operation of the compressor 16, the temperature of
the flow of oil can increase and it may be desirable to cool the
flow of oil. In one construction, the flow of oil exits the
compressor 16 through the oil passage 30 and is passed to the oil
cooler 28. The oil cooler 28 cools the flow of oil and then the oil
passage 30 directs the flow of oil back to the compressor 16 to be
re-used to cool and lubricate the compressor components.
[0033] The refrigeration system 14 is operable to produce a cool
flow of refrigerant. The flow of refrigerant may include any
suitable refrigerant, such as argon or FREON. The refrigeration
compressor 32 is configured to create a compressed flow of
refrigerant that exits the refrigeration compressor 32 and passes
to the condenser 34. The condenser 34 removes heat from the flow of
refrigerant, thereby at least partially condensing the flow of
refrigerant. Next, the flow of refrigerant enters the expansion
device 36 where it is expanded, thereby causing a reduction in the
pressure and temperature of the flow. The expanded flow of
refrigerant exits the expansion device 36 and passes to the
evaporator 38 where the flow of refrigerant is in thermal exchange
relationship with the flow of compressed fluid, such that the flow
of refrigerant cools the flow of compressed fluid.
[0034] The flow of refrigerant exits the evaporator 38 through the
evaporator outlet 42 and flows to the return line 40. A portion of
the flow of refrigerant may be diverted from the return line 40 to
the cooling passage 46. In the cooling passage 46, the portion of
the flow of refrigerant can be further diverted into portions that
are passed to the plurality of cooling passage portions 48. One of
the plurality of cooling passage portions 48 may be in thermal
exchange relationship with the drive member 18 and the flow of
refrigerant within the cooling passage portion 48 is operable to
cool the drive member 18. Another one of the cooling passage
portions 48 may be in thermal exchange relationship with the
after-cooler 26, such that the flow of refrigerant is operable with
the after-cooler 26 to cool the flow of the compressed fluid. Yet
another cooling passage portion 48 may be in thermal exchange
relationship with the oil-cooler 28, such that the flow of
refrigerant is operable with the oil-cooler 28 to cool the flow of
oil. The cooling passage portions 48 may also be in thermal
exchange relationship with the VFD 20 and the control system 22,
such that the flows of refrigerant within the cooling passage
portions 48 are operable to cool the VFD 20 and the control system
22. In other constructions, one of the cooling passage portions 48
can be in thermal exchange relationship with the inter-cooler or
inter-coolers that are configured to cool the flow of compressed
fluid between each stage of compression.
[0035] It should be understood that although the illustrated
compressor assembly 12 includes the after-cooler 26, the oil-cooler
28, the drive member 18, the VFD 20 and the control system 22 all
in thermal exchange relationship with portions 48 of the cooling
passage 46, it is not necessary for all of these components to be
in thermal exchange relationship with the cooling passage 46. For
example, in one construction the oil-cooler 28 can be air cooled
and therefore, the oil cooler 28 may not be in thermal exchange
relationship with the cooling passage 46. In yet another
construction, the after-cooler 26, the oil-cooler 28, the VFD 20
and the control system 22 are all air cooled and only the drive
member 18 is in thermal exchange relationship with the cooling
passage 46. Thus, as one of ordinary skill will realize, any one or
combination of the components can be cooled using the refrigeration
system 14 described herein.
[0036] After the portions of the flow of refrigerant complete the
thermal exchange relationship with the after-cooler 26, the oil
cooler 28, the drive member 18, the VFD 20 and/or the control
system 22, the portions of the flow of refrigerant are passed into
the return line 40. The return line 40 collects the portions of the
flow of refrigerant, along with the portion of the flow of the
refrigerant that was not passed through the cooling passage 46, and
returns the flow of refrigerant back to the refrigerant compressor
32. The flow of refrigerant returned to the refrigerant compressor
32 repeats the refrigeration process described above to create the
cool flow of refrigerant.
[0037] Thus, the invention provides, among other things, a
compressor system 10 that includes a compressor 16, a drive member
18 and a refrigeration system 14. The refrigeration system 14 may
operate as part of an air dryer 44 to dry the compressed fluid
exiting the compressor 16 and is also operable to cool other
components such as the drive member 18, a variable frequency drive
20, a control system 22, an after-cooler 26, and/or an oil cooler
28.
* * * * *