U.S. patent application number 12/052599 was filed with the patent office on 2008-10-16 for integrated heat exchangers in a rack for vertical board style computer systems.
This patent application is currently assigned to LIEBERT CORPORATION. Invention is credited to Daniel Baer, Thomas Harvey, Steven Madara, Stephen Sillato.
Application Number | 20080251240 12/052599 |
Document ID | / |
Family ID | 36023033 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080251240 |
Kind Code |
A1 |
Madara; Steven ; et
al. |
October 16, 2008 |
INTEGRATED HEAT EXCHANGERS IN A RACK FOR VERTICAL BOARD STYLE
COMPUTER SYSTEMS
Abstract
A system for cooling heat-generating objects, such as computer
boards situated in a rack, includes an enclosure in which the heat
generating objects are situated. The enclosure has an air inlet and
an air outlet, and a fan induces airflow into the air inlet,
through the enclosure and out the air outlet. A heat exchanger is
situated in the enclosure such that the heat exchanger is in a
spaced apart relationship with the heat-generating object. Air
moving through or past the heat-generating object is warmed, and
the heat exchanger removes the heat before the air exits the
enclosure.
Inventors: |
Madara; Steven; (Dublin,
OH) ; Sillato; Stephen; (Westerville, OH) ;
Harvey; Thomas; (Columbus, OH) ; Baer; Daniel;
(Delaware, OH) |
Correspondence
Address: |
LOCKE LORD BISSELL & LIDDELL LLP;ATTN: IP DOCKETING
600 TRAVIS STREET, 3400 CHASE TOWER
HOUSTON
TX
77002
US
|
Assignee: |
LIEBERT CORPORATION
Columbus
OH
|
Family ID: |
36023033 |
Appl. No.: |
12/052599 |
Filed: |
March 20, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11164187 |
Nov 14, 2005 |
7367384 |
|
|
12052599 |
|
|
|
|
60522857 |
Nov 14, 2004 |
|
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Current U.S.
Class: |
165/122 |
Current CPC
Class: |
H05K 7/20736 20130101;
G06F 1/203 20130101; H05K 7/20781 20130101 |
Class at
Publication: |
165/122 |
International
Class: |
F24H 3/06 20060101
F24H003/06 |
Claims
1-18. (canceled)
19. A enclosure for cooling heat generating objects, comprising: at
least a cabinet portion and a door portion, the enclosure having an
air inlet and an air outlet; at least one rack located in the
cabinet portion for operatively connecting at least one heat
generating object; a fan associated with the enclosure for inducing
air into the housing through the air inlet, establishing air flow
within the housing and expelling air out of the housing through the
air outlet; an air-to-fluid heat exchanger located in the cabinet
portion and in the air flow path between the air inlet and the heat
generating object; and whereby the air expelled from the housing is
substantially the same temperature as the air entering the
enclosure.
20. The enclosure of claim 19, wherein the fan is situated adjacent
the air outlet and outside of the housing.
21. The enclosure of claim 19, wherein the fan is situated adjacent
the air inlet and outside of the housing.
22. The enclosure of claim 19, wherein the location of the fan is
selected from the group consisting of: adjacent the air inlet and
outside the housing; adjacent the air inlet and inside the housing;
adjacent the air outlet and outside the housing; and adjacent the
air outlet and inside the housing.
23. The enclosure of claim 19, further comprising a second
air-to-fluid heat exchanger located between the heat generating
object and the air outlet.
24. The enclosure of claim 19, wherein the air-to-fluid heat
exchanger is a micro-channel heat exchanger.
25. The enclosure of claim 24, wherein the heat exchanger is
adapted to transfer heat from the air to a refrigerant.
26. The enclosure of claim 25, wherein the refrigerant is a
two-phase refrigerant.
27. The enclosure of claim 19, further comprising a plurality of
racks, each rack adapted to operatively connect a plurality of
vertically-oriented heat generating objects to the rack.
28. The enclosure of claim 27, further comprising at least one heat
exchanger located between each rack.
29. The enclosure of claim 28, wherein the at least one heat
exchanger located between each rack is an air-to-fluid heat
exchanger.
30. The enclosure of claim 29, wherein the at least one heat
exchanger located between each rack is a micro-channel heat
exchanger.
31. The enclosure of claim 30, wherein the at least one heat
exchanger located between each rack is adapted to transfer heat
from the air to a refrigerant.
32. The enclosure of claim 31, wherein the refrigerant is a
two-phase refrigerant.
33. A method for cooling heat generating objects located within an
enclosure, comprising: providing an enclosure comprising at least a
cabinet portion and a door portion, the enclosure having an air
inlet and an air outlet; locating at least one rack within the
cabinet portion for operatively connecting at least one heat
generating object to the rack; associating a fan with the enclosure
to induce air into the housing through the air inlet; placing an
air-to-fluid heat exchanger in the cabinet portion and in an air
flow path between the air inlet and the rack to transfer heat from
the air; establishing air flow through the heat exchanger and
across the rack to transfer heat to the air; and expelling air out
of the housing through the air outlet at substantially the same
temperature as the air entering the inlet.
34. The method of claim 33, wherein associating the fan comprises
locating the fan adjacent the air outlet and outside of the
housing.
35. The method of claim 33, wherein associating the fan comprises
locating the fan adjacent the air inlet and outside of the
housing.
36. The method of claim 33, wherein associating the fan is selected
from the group consisting of: adjacent the air inlet and outside
the housing; adjacent the air inlet and inside the housing;
adjacent the air outlet and outside the housing; and adjacent the
air outlet and inside the housing.
37. The method of claim 33, further comprising placing a second
air-to-fluid heat exchanger between the rack and the air
outlet.
38. The method of claim 33, wherein the air-to-fluid heat exchanger
is a micro-channel heat exchanger.
39. The method of claim 38, wherein the heat exchanger is adapted
to transfer heat from the air to a refrigerant.
40. The method of claim 39, wherein the refrigerant is a two-phase
refrigerant.
41. The method of claim 33, further comprising locating a plurality
of racks within the cabinet portion, each rack adapted to
operatively connect a plurality of vertically oriented-heat
generating objects to the rack.
42. The method of claim 41, further comprising placing at least one
heat exchanger between each rack.
43. The method of claim 42, wherein the at least one heat exchanger
between each rack is an air-to-fluid heat exchanger.
44. The method of claim 43, wherein the at least one heat exchanger
between each rack is a micro-channel heat exchanger.
45. The method of claim 44, wherein the at least one heat exchanger
located between each rack is adapted to transfer heat from air to a
refrigerant.
46. The method of claim 45, wherein the refrigerant is a two-phase
refrigerant.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application Ser. No. 60/522,857 filed Nov. 14, 2004, the
contents of all of which are incorporated herein by reference.
BACKGROUND
[0002] The present disclosure relates to systems for cooling
electronic and other heat-generating equipment, and more
particularly to systems for cooling the air flowing in proximity to
electronic equipment configured in vertical banks in a rack or
cabinet.
[0003] The growth of the computer industry over the past few
decades has been phenomenal. Many new computer designs combine
multiple computer/processor boards to make "high end" computers and
"servers". Due to the demand for floor space, computer boards are
often configured to be "stacked" vertically in a rack or cabinet.
Many existing cooling systems for electronic equipment contained in
such a vertical rack do not provide adequate cooling. In many of
these cooling systems, air is drawn into the bottom of the rack or
cabinet containing computer boards and moved vertically through the
cabinet, progressively cooling the respective computer boards. In
this design, the boards mounted "higher" in the rack receive warmer
air than those mounted toward the bottom because the air has
already passed over and absorbed heat from one or more boards.
Consequently, the "higher" boards are not adequately cooled by the
flow of warmer air.
[0004] At the same time, newer, more powerful microprocessors are
constantly being introduced, but this higher performance is
generally accompanied by significantly increased heat generation.
Thus, these newer processor configurations are driving up heat
loads to the point that "unaided" air cooling cannot provide enough
capacity to keep these "stacked" computers from overheating. As a
result, "stacked" servers may have to operate at reduced processing
speeds to limit the heat load, which in turn compromises
performance.
[0005] In addition, existing cooling systems have a rather limited
cooling capability. For instance, many existing cooling systems
have heat densities of approximately 80 watts per square foot
(W/ft.sup.2), though some cooling systems still under development
are said to possess heat densities of up to 150 W/ft.sup.2. Even
cooling systems having these heat densities, however, may not
effectively cool today's state-of-the-art electronic equipment.
[0006] As is readily apparent, if equipment is not sufficiently
cooled, the internal temperature of the electronic components in
the equipment dramatically increases over relatively short periods
of time, which may result in significantly reduced system
performance and, in some cases, component or total system failure.
Even where system performance is not compromised, inefficient
cooling may unnecessarily increase the cost of cooling the
equipment. Thus, there remains a need for a cooling system that
adequately and efficiently cools computer boards configured in
vertical banks in a rack.
SUMMARY
[0007] A system for cooling heat generating objects, such as
computer boards situated in a rack, includes an enclosure in which
the heat generating objects are situated. The enclosure has an air
inlet and an air outlet, and a fan induces air flow into the air
inlet, through the enclosure and out the air outlet. The fan may be
situated adjacent the air inlet or outlet, or multiple fans may be
used at the inlet and outlet. A heat exchanger is situated in the
enclosure such that the heat exchanger is in a spaced apart
relationship with the heat-generating object. Air moving through or
past the heat-generating object is warmed, and the heat exchanger
removes the heat before the air exits the enclosure.
[0008] In certain exemplary embodiments, the heat exchanger is
situated adjacent the air inlet. In further embodiments, the heat
exchanger is situated adjacent the air outlet, or heat exchangers
are situated at both the inlet and outlet of the enclosure. Often,
a plurality of heat-generating objects are situated vertically in
the enclosure, and a plurality of heat exchangers are situated in
the enclosure such that a heat exchanger is situated between
adjacent heat generating objects in a spaced-apart
relationship.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other objects and advantages of the invention will become
apparent upon reading the following detailed description and upon
reference to the drawings in which:
[0010] FIG. 1 is a perspective view schematically illustrating a
system for cooling heat generating objects in a cabinet.
[0011] FIG. 2 is a perspective view schematically illustrating an
alternative system for cooling heat generating objects in a
cabinet.
[0012] FIGS. 3 and 4 are front and side views, respectively,
schematically illustrating another system for cooling heat
generating objects in a cabinet.
[0013] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof have been shown
by way of example in the drawings and are herein described in
detail. It should be understood, however, that the description
herein of specific embodiments is not intended to limit the
invention to the particular forms disclosed, but on the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DETAILED DESCRIPTION
[0014] Illustrative embodiments of the invention are described
below. In the interest of clarity, not all features of an actual
implementation are described in this specification. It will of
course be appreciated that in the development of any such actual
embodiment, numerous implementation-specific decisions must be made
to achieve the developers' specific goals, such as compliance with
system-related and business-related constraints, which will vary
from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time-consuming, but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
[0015] Turning now to FIG. 1, therein is illustrated an embodiment
of a cooling system 10 for cooling heat generating objects 12
configured in banks within an enclosure such as a cabinet 16.
Typically, the heat generating objects consist of electronic
assemblies, such as circuit board assemblies, received in racks in
the cabinet 16. The cooling system includes a fan 14, which induces
airflow in the direction of arrow 15, into the cabinet 16 through
an inlet, upwardly and through the cabinet 16, exiting the cabinet
16 through an outlet. It will be apparent to one skilled in the art
that fan 14 can be located at any position that will induce airflow
through cabinet 16, and that a plurality of fans can be used. The
airflow 15 cools the electronic equipment 12 as it passes through
each bank of equipment. The cooling of the electronic equipment 12
causes an increase in the temperature of the flowing air stream,
such that air stream 19 exiting the outlet at the top of cabinet 16
is warmer than that entering the air inlet of the cabinet 16. The
air stream itself is cooled as it passes the heat exchangers 20
located between each bank of electronic equipment 12. The heat
exchangers 20 are spaced apart from the equipment 12 such that an
air space is defined between the equipment 12 and the heat
exchangers 20. The air stream 19 is also cooled as it passes
through the top heat exchanger 18 and exits outward, away from the
components within cabinet 16, so that it does not add any
unnecessary heat load to the room air conditioning.
[0016] Another system 10A is shown in FIG. 2, wherein a heat
exchanger 22 is in front of, or alternately, before the first heat
load or heat-generating device 12. As illustrated in FIG. 2, front
heat exchanger 22 can be placed in-between fan 14 and the first
heat-generating device 12. This allows for air to be "pre-cooled"
prior to entering into or around the heat-generating devices. In a
typical scenario, fan 14 induces airflow in the direction of arrow
15, upwardly and into cabinet 16 through an air inlet. The airflow
first passes through front heat exchanger 22, where it is cooled
prior to coming into contact with the heat generating devices 12.
The now pre-cooled air then flows upwardly, through and/or around
heat generating devices 12, and optionally through one or more
additional, intermediate heat-exchangers 20, before passing through
top heat exchanger 18 and exiting the cabinet 16 through an air
outlet. As described previously, inclusion of a top heat exchanger
18 allows for the air steam 19 exiting the cabinet 16 to be cooled
prior to exiting into the room, so as to minimize the effect on the
heat load to the room air conditioning. As shown in FIG. 2, the
heat generating devices 12 and the corresponding heat exchangers
18, 20, 22 are in a spaced-apart relationship, such that an air
space is defined between the heat generating object 12 and the
adjacent heat exchanger(s).
[0017] FIGS. 3 and 4 schematically illustrate front and side views
of another exemplary cooling system 10B. As shown therein, cooling
system 10B comprises a first fan 14 spaced in front of, or before
front heat exchanger 22. The system 10B also comprises a plurality
of heat-generating devices 12 arranged vertically (one device 12
positioned above another) within cabinet 16, with one or more heat
exchangers 20 interspaced between them as necessary in order to
obtain the most efficient cooling, as well as a top heat exchanger
18 spaced downstream of the heat-generating devices 12, but still
within cabinet 16. An air space is defined between each device 12
and the adjacent heat exchanger 20. At the top end of system 10B
near the cabinet's air outlet is a second fan, 24, which can be
mounted externally to the cabinet 16, or can be optionally
contained within cabinet 16. The use of a second fan 24 allows for
the air that has been cooled by top heat exchanger 18 to be pulled
upward and/or away from cabinet 16 and the components housed
therein, so as to aid in minimizing addition of extra heat load to
the room air conditioning system. In operation, the airflow stream
is pulled into system 10B by first fan 14, and moves in the
direction of arrow 15. Airflow is directed upward, through the
cabinet, cooling the heat generating devices 12 as it passes
through each bank. This airflow is itself further cooled as it
passes front heat exchanger 20 and through or around the other heat
exchangers 20 interspersed between devices 12. The airflow stream
is then cooled a final time as it passes through or around top heat
exchanger 18, and is drawn upward and out of cabinet 16 by second
fan 24, pushing the air away from cabinet 16 and the components
contained therein.
[0018] The second fan 24, as illustrated in FIGS. 3 and 4, can be
attached directly to the top of cabinet 16. Alternatively, and
equally acceptable, fan 24 can be contained at the upper portion of
cabinet 16, such as intermediate between top heat exchanger 18 and
the air outlet in the top panel of the cabinet. Equally acceptable,
second fan 24 can be separated from the top of cabinet 16 by some
distance, which can range from several millimeters to greater
distances which will depend upon the strength of fan 24. For
example, second fan 24 can be suspended from a roof structure, or
be a part of or added into an existing cooling system.
[0019] FIGS. 1-4 show exemplary systems each having a plurality of
heat generating objects and heat exchangers. Other embodiments
include a single heat exchanger, such as front heat exchanger 22,
downsteam of a heat-generating device such as a bank of computer
boards. Such a cooling system could be particularly useful for
aiding in the cooling of heat-generating equipment that does not
need more than one heat exchanger in order to be effectively and
efficiently cooled. A further advantage of the present invention is
that it is scalable: that is, as many heat exchangers can be added
incrementally as computer size and architecture dictate. As used
herein, the term "downstream" refers to objects which follow
another object, while the term "upstream" refers to objects which
come before (although not necessarily immediately before) another
object. In example, referring to FIG. 1, heat exchangers 20 are
"downstream" of fan 14, and fan 14 is "upstream" of heat generating
objects 12.
[0020] In certain exemplary embodiments, the heat exchangers are
micro-channel refrigerant heat exchangers placed in the air stream
after each vertically oriented bank of computer boards or other
heat-generating device. With the use of micro-channel heat
exchangers, the heat exchangers cool the hot air from each set of
computer boards by transferring heat to a refrigerant (which is
then pumped away) before that air contacts the next set of computer
boards.
[0021] In some exemplary embodiments, the cooling refrigerant used
is a non-conductive, two-phase refrigerant which acts as an
alternative cooling medium instead of water so that a coolant leak
does not pose a risk of an electrical short or similar hazard. This
type of refrigerant allows for better heat transfer capacity in the
same space because of the use of micro channel coils and because
the refrigerant absorbs a significant amount of heat as it
evaporates. The use of a two-phase refrigerant allows the heat
exchangers to operate essentially isothermally, which provides a
uniform air temperature to the computer boards. The use of such a
system also allows for a smaller "footprint" than if water or other
single-phase fluids are used.
[0022] The particular embodiments disclosed above are illustrative
only, as the invention may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having
the benefit of the teachings herein. Furthermore, no limitations
are intended to the details of construction or design herein shown,
other than as described in the claims below. It is therefore
evident that the particular embodiments disclosed above may be
altered or modified and all such variations are considered within
the scope and spirit of the invention. Accordingly, the protection
sought herein is as set forth in the claims below.
* * * * *