U.S. patent application number 13/736391 was filed with the patent office on 2014-07-10 for cooling system for a machine and method of assembly of same.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is GENERAL ELECTRIC COMPANY. Invention is credited to Sachin Vitthal Mahajan.
Application Number | 20140190184 13/736391 |
Document ID | / |
Family ID | 49920158 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140190184 |
Kind Code |
A1 |
Mahajan; Sachin Vitthal |
July 10, 2014 |
COOLING SYSTEM FOR A MACHINE AND METHOD OF ASSEMBLY OF SAME
Abstract
A cooling system for rotating machines, such as electric motors,
is provided. A heat exchanger housing is coupled with the housing
of an electric motor. At least one Peltier effect device is coupled
to an outer wall of the heat exchanger housing. At least one
outflow air passage and at least one return air passage are defined
within the heat exchanger housing to extend between the motor
housing and the outer wall of the heat exchanger housing. The at
least one outflow air passage transports heated air to the outer
wall to facilitate heat transfer from the air to the outer wall.
The at least one Peltier effect device facilitates heat transfer
from the outer wall.
Inventors: |
Mahajan; Sachin Vitthal;
(Hyderabad, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC COMPANY |
Schenectady |
NY |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
49920158 |
Appl. No.: |
13/736391 |
Filed: |
January 8, 2013 |
Current U.S.
Class: |
62/3.2 ;
29/890.035 |
Current CPC
Class: |
H02K 9/10 20130101; F25B
21/02 20130101; Y10T 29/49359 20150115 |
Class at
Publication: |
62/3.2 ;
29/890.035 |
International
Class: |
F25B 21/02 20060101
F25B021/02 |
Claims
1. A cooling system for a machine including a machine housing, said
cooling system comprising: a heat exchanger housing coupled to the
machine housing, said heat exchanger housing comprising an outer
wall, said heat exchanger housing defining at least one outflow air
passage therein and coupled in flow communication with an interior
region defined in the machine housing, said heat exchanger housing
further defining at least one return air passage coupled in flow
communication with the interior region of the machine housing to
enable air to be channeled from the interior region towards said
outer wall for transferring heat from the air to said outer wall;
and at least one Peltier effect device coupled to said outer wall
of said heat exchanger housing, said at least one Peltier effect
device configured to facilitate heat transfer from said outer
wall.
2. A cooling system in accordance with claim 1, wherein said at
least one outflow air passage comprises at least two outflow air
passages separated from each other by a dividing wall.
3. A cooling system in accordance with claim 1, wherein said at
least one outflow air passage extends substantially parallel to
said return air passage.
4. A cooling system in accordance with claim 1, wherein said at
least one outflow air passage extends from the machine housing to
said outer wall.
5. A cooling system in accordance with claim 1, wherein said at
least one return air passage extends from the machine housing to
said outer wall.
6. A cooling system in accordance with claim 1, wherein the machine
includes a rotor shaft, at least one of said at least one outflow
air passage and said at least one return air passage is oriented
substantially perpendicular to the rotor shaft.
7. A cooling system in accordance with claim 1, wherein the machine
housing has a first length, and said heat exchanger housing has a
second length that is approximately equal to the machine housing
first length.
8. A cooling system in accordance with claim 1, wherein said at
least one outflow air passage is adjacent to said at least one
return air passage.
9. A method for assembling a cooling system for a machine including
a machine housing, said method comprising: coupling a heat
exchanger housing to the machine housing, wherein the heat
exchanger housing includes an outer wall; coupling at least one
outflow air passage defined within the heat exchanger housing in
flow communication with an interior region defined in the machine
housing; coupling at least one return air passage defined within
the heat exchanger housing in flow communication with the interior
region of the machine housing and in flow communication with the at
least one outflow air passage, to enable air to be channeled from
the interior region towards the outer wall to facilitate heat
transfer heat from the air to the outer wall; and coupling at least
one Peltier effect device to the outer wall of the heat exchanger
housing, wherein the at least one Peltier effect device facilitates
heat transfer from the outer wall.
10. A method in accordance with claim 9, wherein coupling at least
one outflow air passage comprises: coupling at least two outflow
air passages within the heat exchanger housing; and isolating the
at least two outflow air passages from each other by a dividing
wall.
11. A method in accordance with claim 9, further comprising
coupling said at least one outflow air passage parallel to said
return air passage.
12. A method in accordance with claim 9, further comprising
coupling said at least one outflow air passage to extend from the
machine housing to said outer wall.
13. A method in accordance with claim 9, further comprising
coupling said at least one return air passage to extend from the
machine housing to said outer wall.
14. A method in accordance with claim 9, wherein the machine
includes a rotor shaft, said method further comprising orienting at
least one of said at least one outflow air passage and said at
least one return air passage substantially perpendicular to the
rotor shaft.
15. A method in accordance with claim 9, wherein the machine
housing has a first length, said method further comprising
configuring said heat exchanger housing with a second length that
is approximately equal to the machine housing first length.
16. A method in accordance with claim 9, further comprising
coupling said at least one outflow air passage adjacent to said at
least one return air passage.
17. A machine comprising: a housing; a heat exchanger housing
coupled to the machine housing, said heat exchanger housing
comprising an outer wall, said heat exchanger housing defining at
least one outflow air passage coupled in flow communication with an
interior region defined in the machine housing, said heat exchanger
housing further defining at least one return air passage coupled in
flow communication with said machine housing interior region and in
flow communication with said at least one outflow air passage to
enable air to be channeled from said interior region towards said
outer wall to facilitate heat transfer from said outer wall; and at
least one Peltier effect device coupled to said outer wall, said at
least one Peltier effect device configured to facilitate heat
transfer from said outer wall.
18. A machine in accordance with claim 17, wherein said at least
one outflow air passage comprises two outflow air passages
separated from each other by a dividing wall.
19. A machine in accordance with claim 17, wherein said at least
one outflow air passage extends substantially parallel to said
return air passage.
20. A machine in accordance with claim 17, wherein said at least
one outflow air passage extends from the machine housing to said
outer wall.
Description
BACKGROUND OF THE INVENTION
[0001] The present disclosure relates generally to cooling systems
for use with machines and more particularly, to methods of assembly
for same.
[0002] Machines, such as electric motors, generate heat during
operation as a result of both electrical and mechanical losses.
Typically, an electric motor must be cooled to ensure efficient and
continued operation of the motor. Excessively high motor
temperatures may result in motor bearing failure and/or damage to
the stator and/or to the rotor, in addition to a general loss of
efficiency of the motor.
[0003] Motors are designed based on many considerations. For
example, rotor temperature is a limiting factor in motor design as
the rotor can generate a disproportionally high amount heat. At
least some known electric motors include an enclosure including a
frame and endshields. Electric motor enclosures are typically
either "open" (cage-like) or totally enclosed. In an open
enclosure, ambient air circulates within the enclosure, and heat is
removed via convection between the air and higher temperature motor
components operating within the enclosure. The heated air is
subsequently exhausted from the enclosure. However, the locations
in which open enclosure-type motors can be used are generally
limited.
[0004] In contrast, totally enclosed electric motors are often used
in applications in which the entry of airborne contaminants, such
as dirt, oil, or mist, into the enclosure must be prevented. Forced
convection cooling within a totally-enclosed motor enclosure is
typically provided by a fan coupled to the rotor shaft, external to
the enclosure. However, an external, shaft-mounted fan provides
only limited heat dissipation with respect to the opposite end of
the motor. Consequently, components within the enclosure, such as
drive end bearings, can still overheat due to inefficient cooling.
Shaft-mounted fans also provide only limited heat dissipation with
respect to the rotor. In addition, coupling a fan to the rotor
shaft increases the overall footprint of the motor assembly and
creates drag on the motor that consumes a portion of the power of
the motor.
[0005] Known motor cooling systems typically use air-to-air or
air-to-liquid heat exchangers. However, air-to-air heat exchangers
may produce objectionable noise, and air-to-liquid heat exchangers
are often complex and require more enhanced maintenance
requirements, as compared to air-to-air heat exchangers. Moreover,
both air-to-air and air-to-liquid heat exchangers require large
housings whose dimensions are often larger than those of the motors
to which they are coupled. Accordingly, it would be desirable to
provide a cooling system for machines, such as electric motors,
that provides enhanced and more efficient cooling of a machine, and
that has a physically smaller size as compared to known cooling
systems.
BRIEF DESCRIPTION OF THE INVENTION
[0006] In one aspect, a cooling system for a machine including a
machine housing is provided. The cooling system includes a heat
exchanger housing coupled to the machine housing. The heat
exchanger housing includes an outer wall, the heat exchanger
housing defining at least one outflow air passage therein and
coupled in flow communication with an interior region defined in
the machine housing. The heat exchanger housing further defines at
least one return air passage coupled in flow communication with the
interior region of the machine housing to enable air to be
channeled from the interior region towards the outer wall for
transferring heat from the air to said outer wall. The cooling
system further includes at least one Peltier effect device coupled
to the outer wall of the heat exchanger housing, the at least one
Peltier effect device configured to facilitate heat transfer from
the outer wall.
[0007] In another aspect, a method for assembling a cooling system
for a machine including a machine housing is provided. The method
includes coupling a heat exchanger housing to the machine housing,
wherein the heat exchanger housing includes an outer wall. The
method also includes coupling at least one outflow air passage
defined within the heat exchanger housing in flow communication
with an interior region defined in the machine housing. The method
also includes coupling at least one return air passage defined
within the heat exchanger housing in flow communication with the
interior region of the machine housing and in flow communication
with the at least one outflow air passage, to enable air to be
channeled from the interior region towards the outer wall to
facilitate heat transfer heat from the air to the outer wall. The
method also includes coupling at least one Peltier effect device to
the outer wall of the heat exchanger housing, wherein the at least
one Peltier effect device facilitates heat transfer from the outer
wall.
[0008] In a further aspect, a machine is provided. The machine
includes a housing, and a heat exchanger housing coupled to the
machine housing. The heat exchanger housing includes an outer wall,
the heat exchanger housing defining at least one outflow air
passage coupled in flow communication with an interior region
defined in the machine housing. The heat exchanger housing further
defines at least one return air passage coupled in flow
communication with the machine housing interior region and in flow
communication with the at least one outflow air passage to enable
air to be channeled from the interior region towards the outer wall
to facilitate heat transfer from the outer wall. The machine also
includes at least one Peltier effect device coupled to the outer
wall, the at least one Peltier effect device configured to
facilitate heat transfer from the outer wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side sectional view of an exemplary known motor
cooling system.
[0010] FIG. 2 is a side sectional view of the motor cooling system
illustrated in FIG. 1.
[0011] FIG. 3 is a side sectional view of an exemplary motor
cooling system.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a side sectional view of an exemplary known motor
10, illustrating a motor cooling system 9. In the exemplary
embodiment, motor cooling system 9 includes an air-to-air cooling
circuit 21, and in particular, an ambient air flow portion 23 of
air-to-air cooling circuit 21 is illustrated. Motor 10 includes a
motor housing 11 that substantially completely encloses motor 10,
to substantially prevent intrusion of dirt, oil or other
contaminants into motor 10, as well as to substantially prevent the
escape of motor lubricant from motor 10. Motor 10 includes a rotor
12 that is supported on a rotor shaft 13 that is rotatably coupled
within motor housing 11. Rotor 12 is surrounded by a stator 14
including a plurality of end windings 16. A plurality of fan blades
18 are securely coupled to rotor shaft 13. An impeller 20 is
securely coupled to an end 17 of rotor shaft 13, external to motor
housing 11.
[0013] A heat exchanger housing 24 is mounted atop motor housing
11. Ambient air flow portion 23 of air-to-air cooling circuit 21
includes a vertical plenum 26 and one or more transverse air flow
passages 28 formed in heat exchanger housing 24. Heat exchanger
housing 24 substantially encloses impeller 20. An aperture 25 in
heat exchanger housing 24 enables ambient air 22 to be drawn into
heat exchanger housing 24, along a path illustrated by arrows 29.
Specifically, during operation of motor 10, rotation of rotor shaft
13 causes rotation of impeller 20, thus drawing ambient air 22
through aperture 25, and through vertical plenum 26. Ambient air 22
travels along transverse air flow passage 28, and is eventually
discharged from heat exchanger housing 24 through one or more end
openings 27 defined in heat exchanger housing 24.
[0014] FIG. 2 is a side sectional view of motor 10 and illustrates
an internal cooling air circuit 31. In the exemplary embodiment,
internal cooling air circuit 31 includes a pair of outflow air
passages 30 and 32 that are separated from each other by a wall 15
and by a pair of return air passages 36 and 38. Outflow air passage
30 is separated from return air passage 36 by a wall 39, and
outflow air passage 32 is separated from return air passage 38 by a
wall 41. Outflow air passage 30 is coupled in flow communication
with return air passage 36 via a transverse air passage 35. Outflow
air passage 32 is coupled in flow communication with return air
passage 38 via a transverse air passage 34. Transverse air flow
passage 28 (illustrated in FIG. 1) is isolated from outflow air
passages 30 and 32, and from return air passages 36 and 38, via a
vertical wall (not shown) in heat exchanger housing 24. Outflow air
passages 30 and 32, and return air passages 36 and 38 are coupled
in flow communication with motor 10 via apertures (not shown)
defined in motor housing 11.
[0015] During operation of motor 10, fan blades 18 draw air 33
towards a central region 37 of motor 10, and propel air 33 through
stator 14. Air 33 removes heat from rotor 12 and stator 14. Air 33
is channeled through the apertures defined in motor housing 11 into
air passages 30 and 32. As air 33 rises through outflow air
passages 30 and 32, and subsequently returns through return air
passages 36 and 38, heat is transferred from air 33 through the
vertical wall (not shown) and into ambient air 22 passing through
transverse air flow passage 28 (illustrated in FIG. 1). Although
only one transverse air flow passage 28, one pair of outflow air
passages 30 and 32, and one pair of corresponding return air
passages 36 and 38 are illustrated in FIGS. 1 and 2, in typical
known motors, multiple transverse air flow passages and multiple
pairs of outflow air passages and return air passages are
included.
[0016] Cooling of a motor, such as motor 10, requires the creation
of a temperature gradient between motor 10, specifically high
temperature regions of motor 10, and its surroundings. Motor 10
relies on the use of heat exchanger housing 24 and impeller 20 to
provide cooling for motor 10. In known motor-heat exchanger housing
configurations, a height 43 of heat exchanger housing 24 is often
as much as twice as high as a height 47 of a motor 10. The addition
of impeller 20 to rotor shaft 13 further increases an overall
length 51 of motor 10. Accordingly, a significant volume of space
may be required by the system for cooling motor 10.
[0017] FIG. 3 is a side sectional view of an exemplary motor
cooling system 40 that may be used with motor 10, for example. In
the exemplary embodiment, motor cooling system 40 includes a heat
exchanger housing 42 coupled to a motor housing 44 of an electric
motor 46. In the exemplary embodiment, heat exchanger housing 42
has a length 53 that is approximately equal to a length 57 of motor
housing 44. A rotor 48 is rotatably mounted in motor housing 44 to
a rotor shaft 50. A plurality of fan blades 52 are securely coupled
to opposed ends 61 and 63 of rotor shaft 50, to propel air 45
through motor housing 44 and heat exchanger housing 42 along the
paths illustrated by arrows 76. A stator 49 substantially surrounds
rotor 48. Heat exchanger housing 42 includes a pair of outflow air
passages 54 and 56 that are separated from each other by a wall 55.
Heat exchanger housing 42 also includes a return air passage 58
that is located adjacent to, and separated from, outflow air
passage 54 by a wall 60. Heat exchanger housing 42 also includes a
return air passage 62 that is located adjacent to, and separated
from, outflow air passage 56 by a wall 64. Outflow air passage 54
communicates with return air passage 58 via an opening 66, and
outflow air passage 56 communicates with return air passage 62 via
an opening 68. Each passage 54 and 56, and each passage 58 and 62,
is coupled in flow communication with an interior 59 of motor
housing 44 through apertures (not shown) defined in motor housing
44. Although in the exemplary motor cooling system 40, only one
pair of outflow air passages 54 and 56, and only one pair of return
air passages 58 and 62 are illustrated, in alternative embodiments,
additional outflow air passages and/or return air passages are
provided.
[0018] In contrast to heat exchanger housing 24 (shown in FIGS. 1
and 2), that includes both vertically-extending passages 30, 32,
34, and 36, as well as transverse passage 28, heat exchanger
housing 42 includes only substantially vertically-extending
passages 54, 56, 58, and 62, thus incorporating a simpler heat
exchanger housing configuration. Accordingly, heat exchanger
housing 42 is simpler to construct and maintain than known
air-to-air or liquid-to-air heat exchanger housing
constructions.
[0019] A pair of Peltier effect devices 70 and 72 is securely
coupled to an outer wall 74 of heat exchanger housing 42. Peltier
effect devices 70 and 72 are of any suitable configuration as
needed to enable motor cooling system 40 to function as described
herein. In the exemplary motor cooling system 40, Peltier effect
devices 70 and 72 are powered by an electrical power supply (not
shown), are coupled to suitable control devices (not shown), and
are secured to heat exchanger housing 42 in such a manner, that
when powered, Peltier effect devices 70 and 72 conduct heat away
from heat exchanger housing 42. Specifically, Peltier effect
devices 70 and 72 channel heat conducted through outer wall 74 to
an ambient atmosphere 77 through the creation of a steep
temperature gradient, within each of Peltier effect devices 70 and
72, which is greater than a temperature gradient achievable through
heat transfer accomplished by simple conduction and/or impeller or
fan-induced convection.
[0020] When motor 46 is in operation, rotation of rotor shaft 50
causes fan blades 52 to propel air within motor 46 and heat
exchanger housing 42 (as illustrated by arrows 76) along rotor 48
and through stator 49, in a manner similar to that as described
herein with respect to motor 10 (shown in FIGS. 1 and 2). As heated
air is propelled by fan blades 52 from motor housing 44, and
through outflow air passages 54 and 56 towards outer wall 74, heat
is transferred to outer wall 74. As Peltier devices 70 and 72
function as heat sinks, heat in outer wall 74 is subsequently
transferred away from outer wall 74 by Peltier effect devices 70
and 72, into the ambient atmosphere. Cooled air is channeled away
from outer wall 74 and returned to motor housing 44 via openings 66
and 68, and return air passages 58 and 62. In an exemplary
embodiment, Peltier effect devices 70 and 72 are powered only
during operation of motor 46. In an alternative embodiment, Peltier
effect devices 70 and 72 remain powered for a predefined period of
time after operation of motor 46 has ended, to facilitate continued
cooling of motor 46. In the exemplary embodiment, the use of
Peltier effect devices 70 and 72 means that the circulation of air
45 within heat exchanger housing 42 that is provided by fan blades
52 is sufficient to enable effective removal of heat from air 45,
without the need for an additional impeller, such as impeller 20
(shown in FIG. 1).
[0021] Exemplary embodiments of a cooling system for a machine and
method for assembling same are described above in detail. The
cooling system for a machine and method for assembling same are not
limited to the specific embodiments described herein, but rather,
components of the cooling system and/or steps of the method can be
utilized independently and separately from other components and/or
steps described herein. For example, the cooling systems and
methods described herein can also be used in combination with other
machines and methods, and are not limited to practice with only the
motor as described herein. Rather, the exemplary embodiments can be
implemented and utilized in connection with many other motor and/or
turbine and/or power and/or generator applications.
[0022] Although specific features of various embodiments of the
invention may be shown in some drawings and not in others, this is
for convenience only. In accordance with the principles of the
invention, any feature of a drawing may be referenced and/or
claimed in combination with any feature of any other drawing.
[0023] In contrast to known electric motor cooling systems, the
cooling systems described herein facilitate increased heat
dissipation from the motor, through the use of Peltier effect
devices coupled to the motor housing, in combination with outflow
and return air passages defined within the heat exchanger housing.
In addition, the cooling systems described herein permit electric
motors to be constructed with significantly reduced footprints and
reduced overall package volumes and weights. The cooling systems
described herein also create a steeper temperature gradient between
a motor housing and the ambient surroundings, resulting in more
efficient and effective cooling of an electric motor, and
accordingly, improved motor efficiency. The cooling systems
described herein also eliminate the need for rotor shaft-mounted
impellers or fans. The cooling systems described herein also reduce
maintenance requirements by enabling the use of a simplified heat
exchanger housing. The cooling systems described herein also
provide a reduction in overall motor noise as compared to
fan-equipped air-to-air heat exchanger-provided motors. The cooling
systems described herein also provide for increased bearing life
due to improved cooling of the motor bearings.
[0024] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is formed by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they have structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *