U.S. patent application number 13/251615 was filed with the patent office on 2012-01-26 for heat sink system and assembly.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Theodore Clark Brown, Roland Donajkowski, Ajith Kuttannair Kumar.
Application Number | 20120018138 13/251615 |
Document ID | / |
Family ID | 37895868 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120018138 |
Kind Code |
A1 |
Kumar; Ajith Kuttannair ; et
al. |
January 26, 2012 |
HEAT SINK SYSTEM AND ASSEMBLY
Abstract
A heat sink system with reduced airborne debris clogging, for
cooling power electronics, the heat sink system including a heat
sink having a plurality of fins, a housing configured to direct air
flow around the side, top, and/or bottom of the heat sink and then
through the fins of the heat sink at a back of the heat sink, and
an inlet airway passage formed between a wall of the housing and
said side, top, and/or bottom of the finned heat sink to allow air
to pass within the housing, wherein said side, top, and/or bottom
of the heat sink comprises at least one of said plurality of fins
disposed directly in contact with the inlet airway passage.
Inventors: |
Kumar; Ajith Kuttannair;
(Lawrence Park, PA) ; Brown; Theodore Clark;
(Lawrence Park, PA) ; Donajkowski; Roland;
(Lawrence Park, PA) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
37895868 |
Appl. No.: |
13/251615 |
Filed: |
October 3, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12340824 |
Dec 22, 2008 |
8028744 |
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13251615 |
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11291247 |
Dec 1, 2005 |
7472742 |
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12340824 |
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Current U.S.
Class: |
165/185 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/0002 20130101; F28F 19/00 20130101; H01L 23/3672
20130101; F28F 3/02 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
165/185 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Claims
1. A system comprising: a housing configured to receive airflow
into an inlet airflow passageway; and a heat sink having plural
fins spaced apart from each other and configured to receive the
airflow between the fins from the inlet airflow passageway after
the airflow has flowed through the inlet airflow passageway to
reduce a temperature of the airflow, wherein at least one of the
fins of the heat sink defines at least a portion of the inlet
airflow passageway.
2. The system of claim 1, wherein an outside fin of the fins in the
heat sink is configured to define a portion of the inlet airflow
passageway along a length of the inlet airflow passageway.
3. The system of claim 1, wherein at least two of the fins in the
heat sink are separated from each other by a larger separation
distance than other fins in the heat sink to define a bypass
channel of the heat sink.
4. The system of claim 3, wherein the bypass channel in the heat
sink is positioned in the heat sink to allow a debris-laden portion
of the airflow to flow through the bypass channel.
5. The system of claim 1, wherein the housing includes a transition
seal configured to engage the at least one of the fins of the heat
sink that defines the portion of the inlet airflow passageway to
prevent the airflow from flowing between an interface between the
at least one of the fins and the housing.
6. The system of claim 5, wherein the transition seal includes a
curved portion and the at least one of the fins includes a
complimentary shape to the curved portion.
7. The system of claim 1, wherein the at least one of the fins that
defines the at least the portion of the inlet airflow passageway is
thicker than one or more others of the fins in the heat sink.
8. The system of claim 1, wherein the at least one of the fins that
defines the at least the portion of the inlet airflow passageway is
in direct thermal contact with the airflow prior to the airflow
flowing through the heat sink.
9. The system of claim 1, wherein the at least one of the fins
defines the at least the portion of the inlet airflow passageway by
extending along a side of the inlet airflow passageway.
10. The system of claim 1, wherein the plural fins include inlet
fins and outlet fins, and the inlet fins are disposed within the
inlet airflow passageway such that the airflow flows between the
inlet fins before flowing between the outlet fins.
11. The system of claim 10, wherein at least one of the inlet fins
or the outlet fins includes fins of varying lengths that are
arranged to turn the airflow from the inlet fins to the outlet
fins.
12. The system of claim 10, wherein at least one of the inlet fins
or the outlet fins includes curved fins that define vanes arranged
to turn the airflow from the inlet fins to the outlet fins.
13. The system of claim 1, wherein the housing includes a
restriction element configured to reduce a size of an opening
through which the airflow is received into the inlet airflow
passageway, the restriction element configured to increase a
pressure drop of the airflow as the airflow flows into the inlet
airflow passageway, through the heat sink, and out of the heat
sink.
14. The system of claim 1, wherein at least one of the fins of the
heat sink is divided into a plurality of discrete segments that are
spaced apart from each other along a length of the at least one of
the fins.
15. The system of claim 1, wherein at least one of the fins of the
heat sink has an undulating body.
16. The system of claim 1, wherein the heat sink includes a support
system having grooves configured to receive ends of the fins, with
a first fin of the fins being bent in a first direction and a
second fin of the fins being bent in an opposite, second direction
such that the first fin and the second fin are coupled together in
the heat sink.
17. A system comprising: a heat sink having plural fins spaced
apart from each other, the fins including inlet fins and outlet
fins, with the inlet fins are disposed within an inlet airflow
passageway that receives airflow to be cooled by the heat sink such
that the airflow flows between the inlet fins before flowing
between the outlet fins; wherein at least one of the inlet fins or
the outlet fins are arranged to turn the airflow from the inlet
fins to the outlet fins after the airflow has at least one of
flowed through the inlet fins or before the airflow has flowed
through the outlet fins.
18. The system of claim 17, wherein the at least one of the inlet
fins or the outlet fins are arranged to turn the airflow toward the
outlet fins without the airflow being turned by a housing disposed
outside of or around the inlet fins or the outlet fins.
19. The system of claim 17, wherein at least one of the inlet fins
or the outlet fins include fins of varying lengths.
20. The system of claim 19, wherein the inlet fins include the fins
of varying lengths with the fins having longer lengths located
along an outside of the heat sink and the fins having decreasing
lengths for the fins that are closer to a center of the heat
sink.
21. The system of claim 19, wherein the outlet fins include the
fins of varying lengths with the fins having longer lengths located
along a center of the heat sink and the fins having decreasing
lengths for the fins that are closer to the inlet fins.
22. The system of claim 17, wherein at least one of the inlet fins
or the outlet fins includes curved fins that define vanes arranged
to turn the airflow from the inlet fins to the outlet fins.
23. The system of claim 22, wherein the at least one of the inlet
fins or the outlet fins that includes the curved fins also include
one or more straight fins disposed between two or more of the
curved fins.
24. The system of claim 17, wherein at least two of the fins in the
heat sink are separated from each other by a larger separation
distance than other fins in the heat sink to define a bypass
channel of the heat sink.
25. The system of claim 17, wherein the bypass channel in the heat
sink is positioned in the heat sink to allow a debris-laden portion
of the airflow to flow through the bypass channel.
26. The system of claim 17, wherein at least one of the fins is
divided into a plurality of discrete segments that are spaced apart
from each other along a length of the at least one of the fins.
27. The system of claim 17, wherein at least one of the fins of the
heat sink has an undulating body.
28. The system of claim 17, wherein the heat sink includes a
support system having grooves configured to receive ends of the
fins, with a first fin of the fins being bent in a first direction
and a second fin of the fins being bent in an opposite, second
direction such that the first fin and the second fin are coupled
together in the heat sink.
29. A system comprising: a heat sink configured to be disposed in a
housing having an inlet airflow passageway that receives airflow to
flow through and be cooled by the heat sink, the heat sink having
plural fins spaced apart from each other and configured to receive
the airflow between the fins from the inlet airflow passageway of
the housing, wherein at least one of the fins of the heat sink
defines at least a portion of the inlet airflow passageway in the
housing when the heat sink is disposed within the housing.
30. The system of claim 29, wherein an outside fin of the fins in
the heat sink is configured to define a portion of the inlet
airflow passageway in the housing along a length of the inlet
airflow passageway.
31. The system of claim 29, wherein at least two of the fins in the
heat sink are separated from each other by a larger separation
distance than other fins in the heat sink to define a bypass
channel of the heat sink.
32. The system of claim 29, wherein the at least one of the fins
that defines the at least the portion of the inlet airflow
passageway in the housing is thicker than one or more others of the
fins in the heat sink.
33. The system of claim 29, wherein the at least one of the fins
that defines the at least the portion of the inlet airflow
passageway in the housing is in direct thermal contact with the
airflow prior to the airflow flowing through the heat sink when the
heat sink is disposed within the housing.
34. The system of claim 29, wherein the at least one of the fins
defines the at least the portion of the inlet airflow passageway of
the housing by extending along a side of the inlet airflow
passageway when the heat sink is disposed within the housing.
35. A system comprising: a housing including an inlet airflow
passageway that is configured to receive airflow from outside of
the housing, the housing configured to receive a heat sink having
plural fins spaced apart from each other, wherein the housing is
shaped to receive the airflow, direct the airflow through the inlet
airflow passageway, and between the fins of the heat sink, and
wherein the housing is configured to receive the heat sink into the
housing such that at least one of the fins of the heat sink defines
at least a portion of the inlet airflow passageway.
36. The system of claim 35, wherein the housing is configured to
receive the heat sink such that an outside fin of the fins in the
heat sink is configured to define a portion of the inlet airflow
passageway of the housing along a length of the inlet airflow
passageway.
37. The system of claim 35, wherein the housing includes a
transition seal configured to engage the at least one of the fins
of the heat sink that defines the portion of the inlet airflow
passageway to prevent the airflow from flowing between an interface
between the at least one of the fins and the housing.
38. The system of claim 37, wherein the transition seal includes a
curved portion and the at least one of the fins includes a
complimentary shape to the curved portion.
39. The system of claim 35, wherein the housing is configured to
receive the heat sink such that the at least one of the fins that
defines the at least the portion of the inlet airflow passageway is
in direct thermal contact with the airflow prior to the airflow
flowing through the heat sink.
40. The system of claim 35, wherein the housing includes a
restriction element configured to reduce a size of an opening
through which the airflow is received into the inlet airflow
passageway, the restriction element configured to increase a
pressure drop of the airflow as the airflow flows into the inlet
airflow passageway, through the heat sink, and out of the heat
sink.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority
benefit from U.S. patent application Ser. No. 12/340,824 (filed on
22Dec. 2008, and referred to herein as the "'824 Application"),
which is a continuation of and claims priority benefit from U.S.
patent application Ser. No. 11/291,247 (filed on 1 Dec. 2005, and
referred to herein as the "'247 Application"). The entire
disclosures of the '824 and '247 Applications are incorporated
herein by reference in their entirety.
BACKGROUND
[0002] One or more embodiments of the inventive subject matter
described herein relate to transportation vehicles that use
relatively high power electronics that may require cooling systems
and, more particularly, to a heat sink assembly for reducing airway
blockage in the heat sink assembly.
[0003] Vehicles such as locomotives and related transportation
vehicles can be equipped with power electronics having cooling
systems that use finned heat sinks to aid in heat dissipation.
These heat sinks are cooled by forced air. Previous heat sink
designs have been used which employ typical fin arrangements with
uniform spacing between the fins of the heat sinks. The cooling
capability of the heat sink can depend on the number of fins, the
spacing of the fins, the shape of the fins, and the size of the
fins. An example heat sink that is currently used in locomotives is
one developed by Aavid Thermalloy.
[0004] In some situations, airflow is directed to flow through the
heat sink. Some known designs of heat sinks are susceptible to
plugging with airborne debris such as diesel fumes, dust, dirt, and
the like. When plugged, the effectiveness of the heat sink can be
dramatically reduced, resulting in poorer cooling of the power
electronics that rely on the heat sink for cooling and potentially
increased failure rates of the electronics due to excessive
temperatures the electronics may experience as a result of the
effectiveness of the heat sink being reduced.
BRIEF DESCRIPTION
[0005] One or more embodiments of the presently described inventive
subject matter relate to a system, assembly, and method for cooling
electronics with reduced airborne debris clogging in the heat sink.
In one embodiment, a heat sink system includes a heat sink having a
plurality of fins and a housing configured to direct air flow
around a side, top, and/or bottom of the heat sink and through the
fins of the heat sink at a back of the heat sink. The heat sink
system also includes an inlet airway passage formed between a wall
of the housing and the side, top, and/or bottom of the finned heat
sink to allow air to pass within the housing. In one embodiment,
the side, top, and/or bottom of the heat sink include at least one
of the fins disposed directly in contact with the inlet airway
passage.
[0006] In another embodiment, in a cooling system having a heat
sink system with air passing through an inlet airway passage to
reach a plurality of fins on a heat sink, the heat sink system
includes a transition seal between the heat sink and the inlet
airway passage. The heat sink system may also include a slot
proximate the inlet airway passage to receive an outer fin of the
heat sink. The outer fin is of a thickness to contact the inner
edges of the slot. At least one of the fins can be in thermal
connection with the inlet airway passage.
[0007] In another embodiment, a heat sink assembly includes a base
element defining two dimensions of the heat sink assembly and a
plurality of fins attached to and extending from the base element.
The heat sink assembly also includes an inlet airway passage
through which air travels to reach the plurality of fins, and a
transition seal between the heat sink and the inlet airflow
passage. The heat sink assembly also includes a slot (such as a
ribbed slot) that is located proximate the inlet airflow passage to
receive an outer fin of the heat sink, where the outer fin is of a
thickness to contact inner edges of the slot. At least one of the
fins is in thermal connection with the inlet airflow passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more particular description of the inventive subject
matter briefly described above will be rendered by reference to
specific embodiments thereof that are illustrated in the appended
drawings. Understanding that these drawings depict only typical
embodiments of the inventive subject matter and are not therefore
to be considered to be limiting of its scope, the inventive subject
matter will be described and explained with additional specificity
and detail through the use of the accompanying drawings in
which:
[0009] FIG. 1 illustrates an example of a heat sink system in
accordance with one embodiment;
[0010] FIG. 2 depicts an example embodiment of a cross-section of
the heat sink shown in FIG. 1 along line 2-2 in FIG. 1;
[0011] FIG. 3 depicts an example embodiment of a heat sink system
in accordance with another embodiment;
[0012] FIG. 4 depicts a top view of another embodiment of a heat
sink system;
[0013] FIG. 5 illustrates a top view of one embodiment of the heat
sink shown in FIG. 4;
[0014] FIG. 6 depicts a top view of an example embodiment of a heat
sink system in accordance with another embodiment;
[0015] FIG. 7 illustrates a perspective view of a heat sink system
in accordance with another embodiment;
[0016] FIG. 8 provides a detailed view of a transition seal of the
heat sink system shown in FIG. 7 in accordance with one
embodiment;
[0017] FIG. 9 depicts example leading edge designs for a heat sink
fin;
[0018] FIG. 10 depicts example embodiments of various fin
arrangements;
[0019] FIG. 11 illustrates one embodiment of a straddle mount fin
support system;
[0020] FIG. 12 is an example embodiment of a first fin
arrangement;
[0021] FIG. 13 is another example embodiment of a second fin
arrangement; and
[0022] FIG. 14 is another example embodiment of a third fin
arrangement.
DETAILED DESCRIPTION
[0023] With reference to the figures, example embodiments of the
inventive subject matter will now be described. However, it should
be noted that, though the presently described inventive subject
matter describes various inventions or improvements that may be
used in a heat sink system, these inventions or improvements may be
used individually in a single application or various combinations,
including all versions at once, may be used together. Toward this
end, the example embodiments described herein should not be viewed
as individual inventions since one or more of the embodiments
described herein can be used collectively with one or more other
embodiments as well.
[0024] FIG. 1 illustrates an example of a heat sink system 100 in
accordance with one embodiment. The heat sink system 100 includes a
housing 102 with a heat sink 104 contained in the housing 102. The
housing 102 contains and channels the airflow 106 through the heat
sink 104 to cool the airflow 106. The heat sink 104 can be held in
position by placement of the heat sink 104 between two or more
solid divider walls 108 that oppose each other. The divider walls
108 also separate the heat sink 104 from inlet airflow passages 110
(also referred to herein as airflow passages 110 or inlet paths
110) disposed on opposite sides of the heat sink 104. As shown in
FIG. 1, the divider walls 108 define at least part of the inlet
airflow passages 110 (e.g., by forming one side of each of the
inlet airflow passages 110).
[0025] The heat sink 104 has fins 112 through which the airflow 106
is directed. As the airflow 106 travels through the housing 102 and
through the inlet airflow passageways 110, the airflow 106
experiences bends 114 in the housing 102 and the inlet airflow
passageways 110. As the airflow 106 experiences the bends 114,
heavier debris particles in the airflow 106 may be forced to the
outside of the radius of the bends 114, and may impinge upon a
center 116 of a heat sink face 118 of the heat sink 104 where the
two inlet airflow passageways 110 converge. This phenomenon has
been further verified through debris ingestion testing of heat
sinks 104. Once debris clogging is initiated in the center 116 of
the heat sink 104, plugging of the heat sink 104 can occur and can
then proceed to increase, or grow, across the face 118 of the heat
sink 104 toward the divider walls 108.
[0026] With continued reference to FIG. 1, FIG. 2 depicts an
example embodiment of a cross-section of the heat sink 104 along
line 2-2 in FIG. 1. The heat sink 104 includes the finned heat sink
104having a center-bypass area 120. The fins 112 are laterally
spaced apart by the same or approximately the same separation
distance 200 with at least two of the fins 112 laterally spaced
apart by a greater separation distance 202 than the other fins 112.
The separation of the fins 112 by the greater separation distance
202 creates the bypass area 120 (also referred to herein as a
bypass channel) in the heat sink 104. In the illustrated
embodiment, the bypass area 120 provides an open channel through or
between the center 116 of the heat sink fins 112 which allows for
airborne debris to pass through the heat sink 104 (e.g., through
the bypass area 120) without depositing on the inlet face 118 of
the heat sink 104.
[0027] In one embodiment, the bypass area 120 can be formed by
removing one or more fins 112 from the heat sink 114. To offset
such a removal of the heat sink fins 112, the overall size of the
heat sink 104 may be modified in overall width, fin height, length,
and/or a number of fins 112 to achieve equivalent thermal
performance when compared to a heat sink that does not include the
bypass area 120. This can be achieved with constant spacing between
the fins 112 and a bigger spacing in the bypass area 120, and/or by
having a gradually increased spacing between the fins 112 toward
the center 116 of the heat sink 104. While the bypass area 120 is
shown as being disposed in the center 116 of the face 118 of the
heat sink 104, the bypass area 120 may not be located in the center
116 of the face 118, but may located where a higher or the highest
concentration of debris is expected.
[0028] FIG. 3 depicts an example embodiment of a heat sink system
300 in accordance with another embodiment. The heat sink system 300
includes a housing 302 having housing guide vanes 304 and a finned
heat sink 306. In one embodiment, the heat sink 306 may be similar
to the heat sink 104 shown in FIGS. 1 and 2. The vanes 304 can
include walls disposed in inlet airflow passageways 308 of the
housing 302 that can separate at least some of the debris-laden air
("Dirty Airflow" in FIG. 3) of the airflow 106 that is flowing
through the inlet airflow passageways 308 from the airflow 106 that
does not include debris or includes relatively less debris ("Clean
Airflow" in FIG. 3). For example, the vanes 304 are disposed
between, and spaced apart from, outer surfaces 310 of the inlet
airflow passageways 308 and opposing inner surfaces 312 of the
inlet airflow passageways 308. In the illustrated embodiment, at
least part of the inner surfaces 312 includes divider walls 314,
which may be similar to the divider walls 108 (shown in FIG. 1).
Also as shown in FIG. 3, the vanes 304 may extend from an inlet
face 316 of the heat sink 306 that receives the airflow 106 and
partially along the inlet air passageways 308. The vanes 304 may
have shapes that are at least partially curved to follow or
approximately follow the curvature of the inlet airflow passageways
308.
[0029] Including the vanes 304 in the housing 302 may further
enhance the effectiveness of the heat sink 306 having a bypass area
that is similar to the bypass area 120 (shown in FIG. 1) described
above. For example, the heat sink 104 may be included in the
housing 302 as the heat sink 306 with the bypass area 120 at least
partially disposed between the vanes 304 such that the vanes 304
direct at least some of the Dirty Airflow into the bypass area 120.
For example, the vanes 304 may be used to more precisely control
the amount and specific portion of the airflow 106 that is diverted
or directed through the bypass area 120 (e.g., the Dirty Airflow)
while allowing or directing the other airflow 106 (e.g., the Clean
Airflow) between the fins of the heat sink 104. The vanes 304 may
direct the heavier particles in the airflow 106 to the opening of
the bypass area 120 so as to delay and/or avoid the initiation of
plugging of the spaces between the fins of the heat sink 306.
Although only two vanes 304 are illustrated, a larger number of
vanes 304 may be included in the housing 302.
[0030] As shown in FIG. 3, the heat sink 306 may be mounted between
two divider walls 314 which act to locate the heat sink 306 so as
to channel the airflow 106 through the heat sink 306. Additional
concepts of packaging the heat sink 306 may be employed to increase
the volume of the heat sink 306 without increasing the overall size
and/or weight of the heat sink 306. Increasing the volume of the
heat sink 306 may allow for one or more fins 112 of the heat sink
306 to be removed or moved from the heat sink 306, which in turn
can allow for increased separation distances between the fins 112
without an associated loss in effective heat transfer area of the
heat sink 306.
[0031] FIG. 4 depicts a top view of another embodiment of a heat
sink system 400. The heat sink system 400 includes a finned heat
sink 402 within a housing 404 that does not include the divider
walls on opposite sides of the heat sink 402. For example, the
housing 404 may be similar to the housing 302 (shown in FIG. 3)
with the divider walls 314 (shown in FIG. 3) of the housing 300
removed.
[0032] As shown in FIG. 4, the airflow 106 flows through inlet
airflow passageways 406 disposed between the heat sink 402 and the
housing 404. The airflow 106 moves around sides of the heat sink
402, curves along bends 408 in the housing 404, and flows into an
inlet face 410 of the heat sink 402. In the illustrated embodiment,
the heat sink 402 does not include a bypass channel that is similar
to the bypass channel 120 shown in FIG. 1. Alternatively, the heat
sink 402 may include a bypass channel.
[0033] FIG. 5 illustrates a top view of one embodiment of the heat
sink 402 shown in FIG. 4. Similar to the heat sink 104 (shown in
FIG. 1), the heat sink 402 includes a plurality of fins 500, 502
that are laterally spaced apart from each other. The fins 500, 502
include interior fins 500 and outside fins 502, with the outside
fins 502 disposed outside of, and on opposite sides of, the
interior fins 500. For example, the outside fins 502 may be located
on opposite sides of the heat sink 402.
[0034] In the illustrated embodiment, the outside heat sink fins
502 may have a larger thickness dimension 504 than a thickness
dimension 506 of the interior fins 500. For example, the outside
fins 502 may be made thicker than the interior fins 500 so as to
provide additional structural support and/or to improve heat
transfer rates of the heat sink system 404. Increasing the
thickness dimension 504 of the outside fins 502 can provide the
structural strength that is supplied by the divider walls 314
(shown in FIG. 3) of the heat sink system 300. For example, with
the divider walls 314 not being present in the heat sink system
400, the outside fins 502 can provide the structural strength to
the heat sink 402 that is otherwise provided by the divider walls
314 shown in FIG. 3.
[0035] Additionally, and as shown in FIG. 4, the outside heat sink
fins 502 are disposed along the inlet airflow passageways 406 of
the housing 404. Positioning the outside heat sink fins 502 along
the inlet airflow passageways 406 causes the outside heat sink fins
502 to define at least part of the surfaces of the inlet airflow
passageways 406. As airflow 106 flows through the inlet airflow
passageways 406, at least some of the airflow 106 may come into
direct contact with the outside fins 502. The direct contact
between the airflow 106 and the outside fins 502 can cause at least
some thermal energy (e.g., heat) to be transferred from the airflow
106 to the heat sink 402 before the airflow 106 flows through the
heat sink 402.
[0036] FIG. 6 depicts a top view of an example embodiment of a heat
sink system 600 in accordance with another embodiment. The heat
sink system 600 includes a finned heat sink 602 having several heat
sink fins 604. The heat sink 602 is disposed within a housing 606.
In contrast to the heat sink systems 300 (shown in FIG. 3) and 400
(shown in FIG. 4), the heat sink 602 extends across or through
inlet airflow passageways 608 of the heat sink system 600, as shown
in FIG. 6. For example, the heat sink 602 may laterally extend
across the entirety of the interior of the housing 606.
[0037] FIG. 7 illustrates a perspective view of a heat sink system
700 in accordance with another embodiment. FIG. 8 provides a
detailed view of a transition seal 800 of the heat sink system 700
that is disposed between a heat sink fin 702 of a heat sink 704 of
the heat sink system 700 and a housing 706 of the heat sink system
700 in accordance with one embodiment. While the heat sink 700 is
shown as including fins 702 across the width of the heat sink 700,
alternatively, one or more of the fins 702 may be removed or
otherwise not present to form one or more bypass areas that are
similar to the bypass areas 120 (shown in FIG. 1) of the heat sink
104 (shown in FIG. 1).
[0038] The housing 706 of the heat sink system 700 may be similar
to the housing 302 (shown in FIG. 3) of the heat sink system 300
(shown in FIG. 3), except that the divider walls 312 (shown in FIG.
3) of the housing 302 may be at least partially removed to form the
transition seal 800. For example, at least a portion of the divider
walls 312 may be removed except for a sloped portion 802 (shown in
FIG. 8) at an end of the housing 706. The sloped portion 802 is
provided so as to have a transition seal between the heat sink 704
and the housing 706, including an inlet airflow passage 708 and a
weldment 804. Also, the housing 706 can include a ribbed slot 806
to facilitate the easy location and application of a sealing member
808, such as a gasket. The sealing member 808 can include a
pressure sensitive adhesive on one side. Alternatively, another
type of sealing material may be used.
[0039] The heat sink 704 is constructed with one or more outer or
outside solid fins 702 that have shapes that are complimentary to
the shapes of the sloped portion 802 of the transition seal 800.
For example, the outside fins 702 may have a convex portion with a
radius of curvature that matches the radius of curvature of the
concave portion in the transition seal 800 that is formed by the
sloped portion 802. The outer fins 702 may have appropriate
thicknesses so as to fit into the ribbed slots 806 on opposite
sides of the heat sink 704. The receipt of the outside fins 702
into the ribbed slots 806 may compress the sealing members 808
(e.g., gaskets) that run along the length of the outside fins 702.
The outside fins 702 may act as the divider walls of the housing
700, such as the outside fins 502 (shown in FIG. 5) of the heat
sink system 500 (shown in FIG. 5) act as the divider walls of the
heat sink system 500. For example, the heat sink 704 may replace
the divider walls 314. The engagement between the outside fins 702
and the transition seal 800 may form a seal to the airflow 106 such
that the airflow 106 does not flow between the interface between
the outside fins 702 and the sloped portion 802.
[0040] Even though a transition seal and slope portion are
disclosed to provide a seal between a heat sink and a base,
alternatively, other embodiments are possible to achieve the same
connection wherein the heat sink fins 702 are in thermal connection
with a base. For example, the fins 702, having a rectangular shape,
may have an end that extends to the weldment 804 of the housing
706. The fins 702 that may be located in or adjacent to the inlet
airflow passageways 708 may also be in thermal connection with the
airflow passageways 708.
[0041] In the illustrated embodiment, a controlled restriction
element 810 may be provided at the same end of the housing 706
through which the airflow 106 is received into the inlet airflow
passageways 708. As illustrated in FIG. 7, the restriction element
810 is attached to the housing 706. Alternatively, the restriction
element 810 can be part of or connected to the heat sink 704. This
restriction element 810 may be used to control and/or regulate a
pressure drop through the heat sink 704 due to increased spacing
between two or more of the fins 702 in the heat sink 704. The
restriction elements 810 can increase the pressure drop through or
across the heat sink system 700 by reducing cross-sectional sizes
of openings 710 through which the airflow 106 is received into the
inlet airflow passageways 708.
[0042] In one embodiment, a plurality of heat sinks, such as up to
thirty-six (36), may be used on a vehicle such as a locomotive. The
pressure drop across all of the heat sinks may be uniform. Thus, if
a new heat sink replaces a current heat sink on the locomotive, the
pressure drop across this new heat sink may need to be uniform to
the existing pressure drops across the other heat sinks. Toward
this end, a restriction element 810 is sized to ensure a uniform
pressure drop across the replacement heat sink 704. By doing this,
one heat sink may have a different sized restriction element 810
than another. This allows for ensuring that all future heat sinks
are backward compatible with existing heat sinks in a system, such
as a locomotive.
[0043] For example, if the heat sink 704 includes one or more
bypass areas similar to the bypass area 120 (shown in FIG. 1) of
the heat sink 104 (shown in FIG. 1), then the pressure drop of the
airflow 106 flowing through the heat sink 704 may be smaller than
the pressure drop of the airflow 106 flowing through another heat
sink that does not include a bypass area, or that includes a
smaller number of bypass areas or smaller separation distances
between the fins to form the bypass area. When multiple heat sink
systems are arranged in parallel (such that the airflow 106 may
flow through a plurality of the heat sink systems in parallel), the
pressure drop across each of the heat sink systems may be equal or
approximately equal to avoid substantially more airflow 106 flowing
through one or more of the heat sink systems relative to other heat
sink systems. In a vehicle or system having multiple heat sink
systems, including one or more of the heat sink systems 100, 300,
400, 700 (shown in FIGS. 1, 3, 4, and 7) having heat sinks with one
or more bypass areas 120, the restriction elements 810 may be
included in the heat sink systems to increase the pressure drop
across the heat sink systems 100, 300, 400, 700 to be equal,
approximately equal, or greater than the pressure drops across one
or more other heat sink systems connected in parallel with the heat
sink systems 100, 300, 400, and/or 700. For example, if a vehicle
is retrofitted with a heat sink having one or more bypass areas 120
while one or more other heat sinks disposed in parallel do not have
such bypass areas 120, the restriction elements 810 may be used to
increase the pressure drop across the heat sinks having the bypass
areas up to the pressure drops across the other, non-retrofitted
heat sinks.
[0044] In addition with respect to the housing 706, an access port
712 (not visible but having a location or locations identified in
FIG. 7) is provided to facilitate inspection of heat sink clogging
and/or cleaning of the heat sink 704.
[0045] FIG. 9 depicts example leading edge designs for a heat sink
fin. An improved leading edge design can assist in reducing a rate
of plugging of a heat sink, such as one or more of the heat sinks
108, 306, 402, 602, 704 (shown in FIGS. 1, 3, 4, 6, and 7). In one
embodiment of a design of a heat sink fin 900, shown in in FIG.
9(a), a leading edge 902 has a flat surface 904.
[0046] In another embodiment, a heat sink fin 906 has a leading
edge 908 that is shaped with a pointed, beveled edge 910, as
illustrated in FIG. 9(b). Alternatively, a heat sink fin 912 may
have a leading edge 914 that includes a rounded-off edge 916, as
illustrated in FIG. 9(c). The leading edges 902, 908, 914 may be
disposed at one or more of the leading edge (e.g., the edge of the
fin that contacts the airflow 106 shown in FIG. 1 as the airflow
106 enters the heat sink having the fin) and/or a trailing edge
(e.g., the opposite edge of the fin that contacts the airflow 106
as the airflow 106 exits the heat sink having the fin) of the fins
900, 906, 912. In the case of fin designs that are not solid or
continuous, such as the segmented or augmented fins disclosed
below, one or more of the leading edges 902, 908, 914 may also be
extended to the leading and/or trailing edges of each of a
plurality of fin segments of the fins.
[0047] In another embodiment, a surface finish of one or more fins
in a heat sink may be altered to reduce a propensity of particles
in the airflow 106 (shown in FIG. 1) from sticking to the surface
of the fins. To achieve a non-stick fin, the fin may be processed
to have a very fine surface finish, and/or coatings may be applied
to produce a non-stick surface. Teflon, fluoropolymers, PFA, PTFE,
and FEP are some examples of coatings available that may be applied
to reduce the propensity of particles in the airflow 106 from
sticking to the fins.
[0048] FIG. 10 depicts example embodiments of various fin
arrangements. As illustrated, at least four different concepts for
the fin arrangements are shown. The concepts depicted include, in
FIG. 10(a), an augmented fin 1000 and, in FIG. 10(b), a straight
fin 1002. The augmented fin 1000 has parts 1004 of the fin 1000
that extend into the area where airflow 106 (shown in FIG. 1)
passes, which in turn may cause turbulence. The area of turbulence
can result in debris buildup, or plugging, of a heat sink.
[0049] A configuration of a segmented fin 1006 depicted in FIG.
10(c) includes the fin 1006 divided in a plurality of discrete
segments 1008 that are spaced apart from each other. For example,
as shown in FIG. 10(c), the segments 1008 may be separated from
each other along a length of the fin 1006. The segmented fin 1006
may provide similar turbulence as the augmented fin 1000 without
providing edges or portions of the fin 1006 that stick into the air
stream of the airflow 106. By not having parts of the fin 1006
extending into the airflow 106, the probability of plugging the
heat sink with debris in the airflow 106 may be reduced.
[0050] FIG. 10(d) depicts design of a wavy fin 1010 that likewise
attempts to increase turbulence and heat transfer while removing
leading edges that promote accretion of debris. As shown in FIG.
10(d), the wavy fin 1010 includes an elongated body 1012 having an
undulating shape. The body 1012 may be continuous between opposite
ends 1014, 1016 of the body 1012.
[0051] In addition to providing enhanced clog resistance, edge
treatment of the fins and various fin configurations may be
performed or combined with other parameters such as varied fin
geometry (e.g., thickness, height, and the like of the fins) and/or
fin spacing, to tune and/or reduce the airflow-induced noise
generation of the heat sink. For example, FIG. 11 illustrates one
embodiment of a straddle mount fin support system 1100 that may be
included in a heat sink. The system 1100 may be used to attach each
of a plurality of fins 1102 to a base plate 1104 on a heat sink. As
shown in FIG. 11, the system 1100 may include grooves 1106 that
receive ends 1106 of the fins 1102.
[0052] Since the fin thickness may be small, the support of the
fins 1102 may be provided by bending portions 1110 of the fins
1102. Different fins 1102 may be bent in opposite directions (e.g.,
as shown with respect to the fins "A" and "B") and then supporting
the fins 1102 on the heat sink base 1104. For example, the fins
1102 that are bent in different directions may be coupled together
to form a single fin when the ends 1108 of the fins A and B are
placed into neighboring grooves 1106 of the system 1100.
Alternatively, thicker fins (such as the fins 112 shown in FIG. 2)
may be used and/or more space may be provided between the fins
and/or, the fins may be made thicker, such as illustrated in FIG.
2, so as to have a better heat transfer rate and to be able to
support without bending portions of the fins in opposite
directions.
[0053] FIGS. 12, 13, and 14 are example embodiments of fin
arrangements 1200, 1300, 1400 of varying lengths. The fin
arrangements 1200, 1300, 1400 include fins 1202, 1302, 1402 that
may be included in one or more of the heat sinks described herein,
such as the heat sink 602 shown in FIG. 6. The fin arrangements
1200, 1300, 1400 are described herein with reference to the heat
sink system 600 shown in FIG. 6, but alternatively may be used with
one or more other heat sink systems described herein.
[0054] In one embodiment, FIGS. 12, 13, and 14 show one side of the
fins in a heat sink, such as the fins on one side of a line through
a heat sink taken along line A-A of FIG. 6, wherein the fin
arrangement 1200, 1300, and/or 1400 used in the heat sink is
different than the fin arrangement shown in FIG. 6. For example,
the areas designated as "inlet" in FIGS. 12, 13, and 14 may include
the fins 1202, 1302, 1402 that are in the heat sink 602 and that
are located within one side of the inlet airflow passageway 608. As
illustrated, where the fins 1202, 1302, 1402 are in the inlet
airflow passageway 608, the fins 1202, 1302, 1402 in this area can
be of varied length to direct the path of the airflow 106.
Alternatively, other varied lengths of the fins 1202, 1302, and/or
1402 may be utilized to achieve a similar result in another
embodiment.
[0055] As illustrated in FIG. 12, the fins 1202 in the inlet
airflow passageway 608 are longer toward the left outer edge of the
heat sink 602 (in the view shown in FIG. 12) and then reduce in
length the closer that the fins 1202 are to other heat sink fins
1202 that are used as an outlet 1204 for the airflow 106. For
example, the airflow 106 may flow into the heat sink 602 between
the fins 1202 having varying lengths that decrease as the fins 1202
are farther from the housing 606 that holds the heat sink 602.
These fins 1202 may be referred to as "inlet fins." When the
airflow 106 passes ends of the inlet fins 1202, the airflow 106 may
turn as shown in FIG. 12 due at least in part to the varying
lengths of the inlet fins 1202.
[0056] Other fins 1202 disposed between the inlet fins 1202 and the
line A-A in FIGS. 6 and 12 may conversely increase in length from
the inlet fins 1202 toward the line A-A. For example, the length of
the fins 1202 may increase as the fins 1202 are farther from inlet
fins 1202. The varying length inlet fins 1202 and outlet fins 1202
can cause the airflow 106 to flow through the inlet fins 1202, turn
toward the outlet fins 1202, and flow through the outlet fins 1202
and out of the heat sink 602 at or near the same end of the housing
600 that the airflow 106 is initially received into the heat sink
602. Alternatively, instead of the fins 1202 having varying
lengths, the inlet fins 1202 and/or outlet fins 1202 may have the
same or approximately the same length and be cascaded (e.g.,
staggered in position so that the ends of the fins 1202 are
arranged as shown in FIG. 12) to turn the airflow 106 toward the
outlet fins 1202.
[0057] In another example embodiment, shown in FIG. 13, the inlet
fins 1202 of the embodiment shown in FIG. 12 may be removed such
that the airflow 106 moves through an inlet airflow passageway 1304
that is similar to the inlet airflow passageway 308 (shown in FIG.
3). The fins 1302 may be arranged similar to the outlet fins 1202
shown in FIG. 12 such that the inlet airflow passageway 1304 and/or
the arrangement 1300 of the outlet fins 1302 directs (e.g., turns)
the airflow 106 to the outlet fins 1302.
[0058] In another example embodiment, as illustrated in FIG. 14,
the arrangement 1400 includes the fins 1402a that are of a longer
length and curved and fins 1402b that are of a shorter length and
straight. The fins 1402a may be disposed in and/or define an inlet
airflow passageway (e.g., similar to the inlet airflow passageway
defined by the inlet fins 1202 of FIG. 12). Some of the curved fins
1402a may be curved in a first direction toward the line A-A shown
in FIGS. 6 and 14 and may be referred to as inlet fins. Other
curved fins 1402b may be curved in an opposite, second direction
toward the line A-A and may be referred to as outlet fins.
[0059] The fins 1402 may define turning vanes that turn the airflow
106 from the inlet fins 1402 toward the outlet fins 1402 instead of
having the turning vanes being part of the housing, such as in the
embodiment shown in FIG. 3. As shown in FIG. 14, not every fin 1402
may be curved to define a turning vane. For example, as illustrated
in FIG. 14, every other fin 1402 may be a curved fin 1402a that has
a vane as part of the fin 1402. Alternatively, all of the fins 1402
or a different number or arrangement of the fins 1402 may be curved
and/or straight. The vanes defined by the fins 1402 may be of
varied lengths and can be used to improve turning efficiency and
flow distribution of the airflow 106 through the heat sink. Though
vanes are illustrated on the inlet fins 1402, in another example
embodiment the inlet fins 1402 may not include the vanes.
[0060] When fins of varying length are used and/or curved fins are
used, as discussed above, the housing for the heat sink may no
longer be required. For example, the housing 602 shown in FIG. 6
may not be used as the fins 1202, 1204, 1302, and/or 1402 used in
the heat sink 602 may direct and control the movement of the
airflow 106 in the heat sink 602. Toward this end, one less element
is required within the cooling system, which results in a cost
savings.
[0061] While one or more embodiments of the inventive subject
matter has been described in what is presently considered to be a
preferred embodiment, many variations and modifications may become
apparent to one of ordinary skill in the art. Accordingly, it is
intended that the inventive subject matter not be limited to the
specific illustrative embodiment, but be interpreted within the
full spirit and scope of the appended claims.
* * * * *