U.S. patent application number 11/305411 was filed with the patent office on 2007-06-21 for systems and methods for providing resources such as cooling and secondary power to electronics in a data center.
Invention is credited to David E. Perkins, Joseph F. III Pinkerton.
Application Number | 20070139883 11/305411 |
Document ID | / |
Family ID | 38173174 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070139883 |
Kind Code |
A1 |
Pinkerton; Joseph F. III ;
et al. |
June 21, 2007 |
Systems and methods for providing resources such as cooling and
secondary power to electronics in a data center
Abstract
Systems and methods for providing operational resources such as
cooling and secondary electrical power to electronics in server
racks in data centers is provided. Pressurized air is provided in a
closed loop that is routed through each of the servers to a heat
exchanger. The electronics in the servers are in thermal contact
with the closed loop via a heat sink such that heat from the
electronics is transferred to the closed loop. The heated
pressurized air travels from the server racks to the heat exchanger
which removes the heat from the air and exhausts it to the
atmosphere. The pressurized air in the closed loop may be cooled
through the use of chilled water, stored water, or both, in which
case the closed loop passes through the water prior to traveling to
the heat sinks.
Inventors: |
Pinkerton; Joseph F. III;
(Austin, TX) ; Perkins; David E.; (Austin,
TX) |
Correspondence
Address: |
FISH & NEAVE IP GROUP;ROPES & GRAY LLP
1211 AVENUE OF THE AMERICAS
NEW YORK
NY
10036-8704
US
|
Family ID: |
38173174 |
Appl. No.: |
11/305411 |
Filed: |
December 15, 2005 |
Current U.S.
Class: |
361/696 ;
165/80.4; 257/E23.098 |
Current CPC
Class: |
H05K 7/20727 20130101;
H01L 2924/0002 20130101; H01L 23/473 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101 |
Class at
Publication: |
361/696 ;
165/080.4 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Claims
1. A method for providing operational resources to data center
electronics, said method comprising: providing pressurized air in a
closed loop; routing said pressurized air in thermal contact with
said electronics such that heat from said electronics is
transferred to said pressurized air which heats said pressurized
air; and directing said heated pressurized air to a system heat
exchanger which changes said heated pressurized air to unheated
pressurized air.
2. The method defined in claim 1, further comprising: generating
secondary power by using said pressurized air to drive a turbine in
the event of a fluctuation in power from a primary power
source.
3. The method defined in claim 2, wherein generating comprises:
providing heated pressurized air to said turbine to drive said
turbine.
4. The method defined in claim 2, wherein generating comprises:
providing pressurized air to said turbine to drive said turbine
which causes said turbine to exhaust cool air that provides cooling
to said electronics.
5. The method defined in claim 1, wherein providing comprises:
driving said pressurized air with a sealed pump so that it flows in
a cyclic manner through said closed loop.
6. The method defined in claim 1, wherein routing comprises:
physically coupling at least one heat sink to said electronics; and
directing said pressurized air through said heat sink.
7. The method defined in claim 1, wherein routing comprises:
locating at least one local heat exchanger in proximity to said
electronics; and directing said pressurized air through said local
heat exchanger; and using blowers to transfer heat from said
electronics to said local heat exchanger.
8. The method defined in claim 1, further comprising: cooling said
pressurized air prior to routing said pressurized air.
9. The method defined in claim 8, wherein cooling comprises:
providing chilled water from a chiller plant; and locating a
portion of said closed loop within said chilled water.
10. The method defined in claim 9, wherein cooling further
comprises: providing water in a water tank, said water being at a
temperature that is lower than said pressurized air prior to said
pressurized air being routed; and locating a portion of said closed
loop within said water tank.
11. The method defined in claim 9, wherein cooling further
comprises: providing water in a water tank, said water, for a first
portion of a twenty-four hour period, being at a temperature that
is lower than said pressurized air prior to said pressurized air
being routed, and said water, for a second portion of said
twenty-four hour period, being at a temperature that is higher than
said pressurized air prior to said pressurized air being routed;
and locating a portion of said closed loop within said water
tank.
12. The method defined in claim 8, wherein cooling comprises:
providing water in a water tank; and locating a portion of said
closed loop within said water tank.
13. The method defined in claim 1, wherein directing comprises:
directing said heated pressurized air to said system heat exchanger
that extracts heat from said heated pressurized air and exhausts
said heat into said atmosphere.
14. The method defined in claim 2, wherein generating comprises:
utilizing an electrical device to provide extremely short-term
bridging power as a portion of said secondary power; rotating a
turbine using said heated pressurized air, said rotation generating
electrical power; and providing said generated electrical power as
a portion of said secondary power.
15. The method defined in claim 14, wherein said electrical device
is a capacitor.
16. The method defined in claim 14, further comprising: operating a
backup generator to provide secondary power in the event of a
long-term disruption in primary power.
17. A method for providing operational resources to data center
electronics, said method comprising: maintaining pressurized air in
a closed loop; passing said pressurized air in thermal contact with
said electronics to transfer heat from said electronics to said
pressurized air; and utilizing a system heat exchanger to remove
heat from said heated pressurized air prior to passing said
pressurized air in thermal contact with said electronics.
18. The method defined in claim 17, further comprising: generating
secondary power, if needed due to a fluctuation in primary power,
by extracting at least a portion of said pressurized air and
driving a turbine with said extracted air.
19. The method defined in claim 18, wherein generating comprises:
extracting heated pressurized air to drive said turbine.
20. The method defined in claim 18, wherein generating comprises:
extracting pressurized air to drive said turbine which causes said
turbine to exhaust cool air that provides cooling to said
electronics.
21. The method defined in claim 17, wherein maintaining comprises:
driving said pressurized air with a sealed pump so that it flows in
a cyclic manner through said closed loop.
22. The method defined in claim 17, wherein passing comprises:
physically coupling at least one heat sink to said electronics;
inputting said pressurized air into an input on said heat sink; and
outputting said pressurized air from an output on said heat sink,
said output pressurized air being heated by said electronics.
23. The method defined in claim 17, further comprising: cooling
said pressurized air prior to passing said pressurized air in
thermal contact with said electronics.
24. The method defined in claim 17, wherein cooling comprises:
causing chilled water to be in thermal contact with said closed
loop.
25. The method defined in claim 24 further comprising: causing said
closed loop to be in thermal contact with water in a water tank
that is maintained at a lower temperature than said pressurized
air.
26. The method defined in claim 24 further comprising: causing said
closed loop to be in thermal contact with water in a water tank
that, for a first portion of a twenty-four hour period, is
maintained at a lower temperature than said pressurized air, and
for a second portion of said twenty-four hour period is at a higher
temperature than said pressurized air.
27. The method defined in claim 18, wherein generating secondary
power comprises: extracting at least a portion of said pressurized
air; and driving a turbine with said pressurized air, said turbine
being coupled to a generator that generates said secondary
power.
28. The method defined in claim 27, wherein generating secondary
power further comprises: providing bridging power to said
electronics while said turbine is being started from a capacitor
coupled to said electronics.
29. A method for providing operational resources to data center
electronics, said method comprising: providing pressurized air in a
closed loop; locating at least one local heat exchanger in
proximity to said electronics; directing said pressurized air
through said local heat exchanger; and using blowers to transfer
heat from said electronics to said local heat exchanger such that
heat from said electronics is transferred to said pressurized air
which heats said pressurized air; and moving said heated
pressurized air to a system heat exchanger which changes said
heated pressurized air to unheated pressurized air.
30. The method defined in claim 29 further comprising: generating
secondary power by using pressurized air to drive a turbine in the
event of a fluctuation in power from a primary power source.
31. The method defined in claim 30, wherein generating comprises:
using heated pressurized air from said closed loop to drive said
turbine.
32. The method defined in claim 29, wherein providing comprises:
causing said pressurized air to flow in a cyclic manner through
said closed loop through use of a sealed pump coupled to said
closed loop.
33. A system that provides operational resources to data center
electronics comprising: a closed loop of pressurized air; at least
one heat sink coupled to said electronics, said heat sink being in
thermal contact with said closed loop; and at least one heat
exchanger coupled to and in thermal contact with said closed
loop.
34. The system defined in claim 33, further comprising: at least
one turbine coupled to said closed loop; and a generator coupled to
each turbine to be driven by said turbine, said generator being
operable to generate secondary power in the event of a fluctuation
in power from a primary power source.
35. The system defined in claim 34, wherein said turbine is coupled
to said closed loop downstream of said heat exchanger such that
heated pressurized air from closed loop can be used to drive said
turbine.
36. The system defined in claim 33, further comprising: a sealed
pump coupled to said closed loop that drives said pressurized air
around said closed loop.
37. The system defined in claim 33, further comprising: a container
that holds water cooled by a chiller plant, said closed loop
passing through said container prior to being coupled to said at
least one heat sink.
38. The system defined in claim 33, further comprising: a water
storage tank that holds water at a temperature lower than the
temperature of said closed loop, said closed loop passing through
said tank prior to being coupled to said at least one heat
sink.
39. The system defined in claim 33, further comprising: a water
storage tank that, for a first portion of a twenty-four hour
period, holds water at a temperature lower than the temperature of
pressurized air in said closed loop, and for a second portion of
said twenty-four hour period, holds water at a temperature higher
than the temperature of pressurized air in said closed-loop, said
closed loop passing through said tank prior to being coupled to
said at least one heat sink.
40. The system defined in claim 34, further comprising: at least
one electronic device that provides bridging power in the event of
a fluctuation in primary power prior to secondary power being
generated by said at least one generator.
41. The system defined in claim 40, wherein said electronic device
is a capacitor.
42. A system that provides operational resources to data center
comprising a plurality of server racks which contain electronics,
said system comprising: a closed loop of pressurized air, said
closed loop being coupled to pass through said plurality of server
racks; a plurality of heat exchangers coupled to and in thermal
contact with said closed loop, said heat exchangers being operable
to extract heat from pressurized air passing through said closed
loop; and for each server rack in said plurality of server racks:
at least one heat sink coupled to and in thermal contact with said
electronics, said heat sink having an input coupled to one portion
of said closed loop and an output coupled to another portion such
that said closed loop passes through said heat sink.
43. The system defined in claim 42, further comprising: a turbine
coupled to said closed loop to receive pressurized air from said
closed loop in the event of a fluctuation in power from a primary
power source; and a generator coupled to said turbine, said
generator being operable to generate secondary power when driven by
said turbine.
44. The system defined in claim 43, wherein said turbine is coupled
to said closed loop downstream of said heat sink such that said
turbine receives heated pressurized air in the event of a
fluctuation in power from said primary power source.
45. The system defined in claim 42, further comprising: a sealed
pump coupled to said closed loop that drives said pressurized air
around said closed loop.
46. The system defined in claim 42, further comprising: a chiller
plant that produces chilled water; and a container that receives
said chilled water, said closed loop passing through said container
prior to being coupled in thermal contact with said heat sinks.
47. The system defined in claim 42, further comprising: a storage
tank that contains water at a temperature lower than the
temperature of pressurized air said closed loop, said closed loop
passing through said tank.
48. The system defined in claim 42, further comprising: a storage
tank that, for a first portion of a twenty-four hour period,
contains water at a temperature lower than the temperature of
pressurized air in said closed loop, and for a second portion of
said twenty-four hour period, contains water at a temperature
higher than pressurized air in said closed loop, said closed loop
passing through said tank.
49. The system defined in claim 42, further comprising: for each
server rack in said plurality of server racks: a capacitor that
provides bridging power in the event of a fluctuation of power from
said primary source of power.
50. A data center comprising: a plurality of server racks, each
server rack containing one or more servers, each server containing
one or more processors; a source of primary power; an
uninterruptible power supply (UPS), coupled to said source of
primary power, that controls the quality of power delivered to said
plurality of servers; and a pressurized closed loop air cooling
system comprising: at least one heat exchanger; and a closed loop
of pressurized air, a portion of said closed loop being in thermal
contact with at least one processor in each of said plurality of
server racks.
51. The data center defined in claim 50, wherein said cooling
system further comprises: a sealed pump coupled to said closed loop
that drives said pressurized air around said closed loop.
52. The data center defined in claim 50, wherein at least one of
said plurality of server racks comprises: a turbine coupled to said
closed loop to receive pressurized air from said closed loop in the
event of a fluctuation in power from said primary power source; and
a generator coupled to said turbine, said generator being operable
to generate secondary power when driven by said turbine
53. The data center defined in claim 52, wherein said turbine is
coupled to said closed loop downstream of said processor such that
said turbine receives heated pressurized air from said closed
loop.
54. A data center comprising: a plurality of server racks; a closed
loop of pressurized air, said closed loop being coupled to pass in
proximity to at least one of said plurality of server racks; a
plurality of system heat exchangers coupled to and in thermal
contact with said closed loop, said system heat exchangers being
operable to extract heat from pressurized air passing through said
closed loop; and for each server rack in said plurality of server
racks: blowers that remove heat from electronics within said server
rack; and at least one local heat exchanger coupled to said closed
loop that takes at least a portion of said removed heat and
utilizes it to heat said pressurized air.
55. The data center defined in claim 54, wherein at least one of
said plurality of server racks comprises: a turbine coupled to said
closed loop to receive pressurized air from said closed loop in the
event of a fluctuation in power from said primary power source; and
a generator coupled to said turbine, said generator being operable
to generate secondary power when driven by said turbine.
56. The data center defined in claim 55, wherein said turbine is
coupled to said closed loop downstream of said local heat exchanger
such that said turbine receives heated pressurized air from said
closed loop.
57. The data center defined in claim 54, wherein said data center
further comprises: at least one sealed pump coupled to said closed
loop that drives said pressurized air around said closed loop.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to systems and methods for providing
operational resources to data centers. More particularly, this
invention relates to providing operational resources such as
cooling and back-up power to the vast array of racks of electronics
that populate data centers. These racks often include processing
devices such as servers that require high quality, dependable
sources of electric power, and reliable cooling due to the heat
generated by the electronics.
[0002] The information age is upon us, driven by the ability of
anyone with a computer or computer-like device, such as a wireless
hand-held device, to access the numerous information networks that
are spread around the globe. These networks include the Internet as
well as the private networks used by companies to provide
round-the-clock access to office and company information for its
employees, customers and clients. Access to these networks can be
obtained from the home, office, or virtually anywhere.
[0003] In order to provide access to these networks, network
providers utilize dedicated sites that are often referred to as
data centers. These data centers include numerous racks of
electronics that provide various capabilities to its users such as:
data storage, data access, e-mail, network applications, Internet
access, etc. The electronics can include servers (i.e., computers
that may be accessed by multiple users "simultaneously" from remote
locations--servers typically do not provide conventional users with
keyboard/mouse/monitor interfaces (such access, however, may be
provided to a system administrator)), power supplies and access
hardware/software (such as interfaces for T1 lines, broadband
access or dial-up access).
[0004] Often, the racks of electronics are configured to be
somewhat stand-alone, whereby each rack includes at least one
server, a power supply and interface hardware to provide access to
that server. In this manner, the operational capacity of the data
center can be more easily managed, often by simply adding one or
more new server racks as required. Server racks can also be
configured such that they accept multiple servers in the same rack,
such as by way of example, "blade servers." With the increased
density of the electronics associated with each server in any given
rack, the power requirements and heat generation of the racks (and
ultimately the data centers) increases. In addition to the
stand-alone racks of electronics, these data centers often must
also have various support systems to maintain normal operations.
These support systems can include uninterruptible power supplies,
air conditioning systems to provide vast quantities of cooling air
and back-up energy power systems to provide back-up power in the
event of a loss or degradation of primary power (which is often
utility power).
[0005] While the use of individual, stand-alone racks provides
flexibility and ease of management, these advantages are inherently
limited by the amount of power and cooling that are available. For
example, a data center might be initially designed with the
capability for thirty racks of servers even though the initial
system will only include twenty servers. In that case, the air
conditioning system and power system would have to be significantly
upgraded if the system grew beyond thirty servers.
[0006] In addition, one of the most significant expenses incurred
during the operation of the data center is the cost of electricity.
This is due not only to the cost of supplying power to the racks of
electronics, but to the cost of supplying power to the vast number
of compressors that are included in the air conditioning system
needed to provide cooling air to the server racks. In most
instances, the data center includes a raised floor having openings
for each of the server racks (which are themselves open on the
bottom, such that the openings in the floor are aligned with the
servers). The server racks also include a number of blowers
installed at the top of the racks. The cooling air is provided
underneath the raised floor and pulled through the server racks by
the blowers (which also adds to the electricity demands of the
facility), which blow the hot air from the server racks into the
room. The air conditioning system must then extract the excess heat
from the server room and, for example, exhaust it to the
atmosphere.
[0007] In some instances where somewhat precise cooling would be
advantageous, water cooling systems have been employed. These
systems typically utilize water or some other coolant that is
maintained in close proximity to, if not direct contact with, the
components being cooled. For example, personal computers that use
water and/or liquid cooling systems to maintain the temperature of
critical electronic components include the Power Mac G5 sold by
Apple Computer. The liquid cooling subsystems provide a high degree
of cooling such that, for example, the quantity of forced cooling
air can be reduced (so that the noise generated by the fans is
reduced). One of the inherent risks of such systems, however, is
the potential for disaster if the cooling system leaks fluid onto
the powered electronics.
[0008] In view of the foregoing, it is an object of the present
invention to provide improved cooling for data centers.
[0009] It is also an object of the present invention to provide
improved support systems for data centers which can reduce the
demands of the data center for electric power.
[0010] It is an additional object of the present invention to
provide data centers with improved back-up electrical power.
[0011] It is still a further object of the present invention to
promote data centers with integrated cooling and back-up power
capabilities.
SUMMARY OF THE INVENTION
[0012] These and other objects of the invention are accomplished by
replacing conventional air conditioning systems in a data center
with a closed loop of compressed air and heat exchangers. In
addition, the electronics in the server racks are configured with
heat sinks in thermal contact with the electronics. The present
invention may be practiced by either direct thermal contact or by
locating the closed loop in close proximity to the electronics such
that heat is removed from the electronics by conduction and/or
convection (and the term "thermal contact" shall refer to either
configuration for the purposes described herein). A portion of the
closed loop is passed through each of the server racks and through
the heat sinks. The heat from the electronics is transferred to the
compressed air, which is then directed to the heat exchangers. The
heat exchangers are preferably installed with direct access to the
atmosphere, so that heat extracted from the closed loop can be
easily exhausted. Once the heat is extracted, the, cooler
compressed air is once again returned to the servers racks.
[0013] In order to further improve the performance of the closed
loop to extract heat from the server racks, persons skilled in the
art may include one or more subsystems to cool the compressed air
before passing it through the server racks. For example, it may be
advantageous to include a chilled water system in the data center
and to run the closed loop through the chilled water prior to the
server racks. It may also be desired to utilize water tanks, kept
at a location away from the electronics, to store water at a
temperature lower than that of the compressed air after the heat
exchangers, and to pass the closed loop through the water tanks
prior to the server racks (or, it may be desirable to utilize both
the chilled water subsystem and the water storage tanks).
[0014] The present invention may also include an air turbine,
generator and support electronics in each server rack to provide
short term back-up power in the event of a loss or degradation of
power from the primary source. In this configuration, the closed
loop would include routing to the turbine after exit from the heat
sinks (through valves that would be normally closed). In the event
of a disruption in primary power (either quality or quantity), the
valve would open and the heated compressed air would drive the
turbine. A generator coupled to the turbine would produce the
back-up electricity. In addition, it may be advantageous to include
a capacitor in each server rack to provide bridging power for the
brief instant that primary power is failing and prior to the
turbine being up to speed.
[0015] In another aspect of the present invention, a control system
can be used to monitor the temperature of the various heat sinks.
In the event that hot spots occur (i.e., instances where one server
rack might be hotter than others), the control system could direct
additional compressed air to the affected heat sinks so that all of
the server racks are maintained at a relatively constant
temperature.
[0016] The present invention provides many advantages over
conventional systems. For example, by eliminating or reducing the
size of the conventional air conditioning systems, overall cost for
electricity is significantly reduced. In addition, eliminating the
forced air approach reduces the manufacturing cost of the server
racks, because the blowers are no longer needed, as well as the
associated reduction in electric demands from the use of the
blowers.
[0017] Another advantage of the present invention is that it
eliminates some of the inherent problems related to expansion of
the data center because each server rack is independently cooled.
When a new rack is added, compressed cooling air may be brought
into the rack without concern for exceeding the existing air
conditioning capacity of the center. In addition, because each
server rack is independently cooled, the data center can be more
densely populated with server racks, and each rack may be more
densely populated with servers and electronics.
[0018] A further advantage of the present invention is the
elimination of the batteries that are often used to provide
short-term back-up power to the system. These batteries usually are
accompanied by a complex system to charge and maintain the
batteries (and safely exhaust the potentially explosive gases
emitted by the batteries). By integrating the back-up power system
with the improved cooling system, the present invention provides a
highly efficient, low cost and relatively simple solution to many
of the problems faced by data centers operators.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other features of the present invention, its
nature and various advantages will become more apparent upon
consideration of the following detailed description, taken in
conjunction with the accompanying drawings, in which like reference
characters refer to like parts throughout, and in which:
[0020] FIG. 1 is an illustrative schematic diagram of a data center
that is provided with operational resources in a conventional
manner;
[0021] FIG. 2 is an illustrative schematic diagram of a data center
that is provided with operational resources in accordance with the
principles of the present invention;
[0022] FIG. 3 is an illustrative schematic diagram of providing
cooling to a server rack in accordance with the principles of the
present invention;
[0023] FIG. 4 is a three-dimensional cutaway view of a processor
heat sink which operates with the cooling systems described herein
in accordance with the principles of the present invention; and
[0024] FIG. 5 is a three-dimensional diagram of a rack-mountable
turbine-based back-up energy system that operates in accordance
with the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIG. 1 shows a schematic of a conventional data center 100
which includes: server racks 102, compressor-driven air
conditioning units 106, lead-acid batteries 114 and uninterruptible
power supply 116 (UPS 116). Server racks 102, which are often
populated with a number of rack-mounted processor-based servers
(not-shown), are typically constructed in such a manner that most,
if not all, of the bottom of the rack is open to receive cooling
air. In addition, racks 102 also often includes electric blowers
112 which operate to pull the cooling air through the rack.
[0026] Data center 100 requires two primary resources to operate:
electricity and cooling. Under normal operation, electric power is
provided to data center 100 via primary power, such as utility
power. The majority of electric power used by data center 100 is
used by the processors in the individual servers mounted in racks
102 and by air conditioning units 106. In addition, blowers 112,
which are constantly running, consume most of the remaining power
used by the data center. The electric power input to data center
100 is monitored by UPS 116, which may include conditioning and
switching circuitry that operates to control the quantity and
quality of power provided to the servers in racks 102.
[0027] In the event of a fluctuation in primary power, UPS 116
operates to maintain the delivered power as a relatively constant
supply such that data center 100 does not generally experience the
effects of the fluctuation. The fluctuation may include extremely
short-term losses in power (such as for durations of less than one
second), short-term losses in power (such as for durations of less
than 15-20 minutes), long term power loss (which may extend
indefinitely), and spikes or variations in the quality of input
power. UPS 116 may include circuitry to ride-through or bridge
extremely short-term power losses, spikes and variations, while
utilizing energy from lead-acid batteries 114 for short term power
losses. Long term power outages are often dealt with by external
fuel-driven generators (not shown) that can operate indefinitely
provided that they are refueled on a regular basis.
[0028] In addition to electricity, data center 100 must be provided
with cooling due to the high levels of heat generated by the
electronics in each of the servers in racks 102. In particular, the
individual processors that run each of the servers in racks 102
generate a substantial amount of the excess heat that must be
removed from server racks 102 to prevent overheating that would
invariably lead to system shutdowns.
[0029] Data center 100 receives its cooling resources from a series
of compressor-based air conditioning units 106 that may be mounted
on roof 118 of data center 100. Air conditioners 106 operate on a
vapor-compression refrigeration cycle which lowers the air
temperature and removes moisture (excess humidity) from the air.
The cooled air is provided to racks 102 via ducts 108 which direct
the cooling air under raised floor 104. Server racks 102 are
typically constructed such that most, if not all, of the bottom of
the units are open. Raised floor 104 is installed with openings in
the floor that correspond to the size of server racks 102, which
are aligned over the openings. The cooled air that was provided
under raised floor 104 travels as indicated by arrows 110 into the
bottom of server racks 102. In addition, blowers 112 operate to
pull the cooled air through racks 102.
[0030] Under normal conditions, the compressors on air conditioners
106 and blowers 112 on racks 102 are constantly running to cycle
freshly-cooled air through data center 100. One deficiency in this
approach, however, is the quantity of required cooling air due to
the broad, relatively general application of the cooling air to the
source of heat (i.e., the processors in the servers (in addition to
the large demands for electric power to run the compressors and
blowers).
[0031] FIG. 2 is an illustrative schematic diagram of data center
200 which is constructed and operated in accordance with the
principles of the present invention. Data center 200 includes
server racks 202 and 204 (one instance of server racks 204 is
essentially the same the collection of server racks 202, but are
shown as a single unit for simplification), heat exchangers 208 and
air supply 214. In addition, data center 200 may include a water
holding tank 210 and/or a chilled water container 212 (which would
be coupled to a conventional chilled water system (not shown) that
produces chilled water and circulates it through container
212).
[0032] Data center 200 is provided with cooling resources in a more
directed and efficient manner than for conventional data centers,
such as data center 100. Cooling is provided to data center 200,
and specifically to server racks 202 and 204, via a closed-loop
air-based system (versus the general application cooling via
open-loop systems in conventional data centers). The air is
constantly maintained in a pressurized state so there is no need
for compressors. The cooling system operates by varying the
temperature of the pressurized air in various locations throughout
the closed-loop such that relatively cool pressurized air is
provided to the processors, which heats the air. It is understood
that the air used in embodiments according to the invention need
not be limited to atmospheric air, but can be any type of working
fluid such as, for example, nitrogen, helium, or hydrogen.
[0033] The heated pressurized air is then passed through heat
exchangers 208 which remove the excess heat and direct the cooler
pressurized air back to the server racks again. Heat exchangers 208
may be any type of conventional heat exchangers, including, for
example, a conventional chilled water system. Thus, while heat
exchangers 208 are shown on roof 216 of data center 200, if a
chilled water system is utilized as the system heat exchanger the
closed-loop will pass through chilled water 212 and roof-top heat
exchangers may not be necessary. In any event, air flow throughout
the closed-loop system is maintained by one or more hermetically
sealed (or semi-hermetically sealed) gas pumps (see element 306 of
FIG. 3).
[0034] While the cooling system is, in and of itself, a closed-loop
system, it may be possible to utilize heated pressurized air from
the closed-loop system to drive an energy backup system in
accordance with the principles of the present invention (and which
is described more fully below with respect to FIGS. 3-5). Under
such circumstances, the cooling system is maintained in its
pressurized state by one or more tanks such as air supply 214,
which supply air under pressure to replace the air consumed by the
backup energy system.
[0035] System performance is primarily dependent upon four factors:
the difference in the temperature of the air in the closed-loop
just prior to entering and leaving server racks 202, the difference
in temperature of the pressurized air in the closed loop entering
and leaving heat exchangers 208, the average or nominal pressure of
the air in the closed loop, and fluid flow pressure losses that
determine pumping power requirements. For example, the system will
operate more effectively if the air in the closed-loop is
maintained at 6000 PSI than if it were maintained at 1000 PSI, but
air at 1000 PSI is likely to be more readily available or easier to
provide than 6000 PSI air. In addition, while the present invention
may be practiced with air-to-air heat exchangers to reduce the
temperature of the air in the closed-loop, it may be more effective
to pass the conduits carrying the pressurized air through
air-to-liquid heat exchangers within water holding tank 210 and/or
chilled water container 212.
[0036] Water holding tank 210 may simply be a tank of water that
acts to cool the air passing through the submersed conduit. In
addition to, or instead of water holding tank 210, chilled water
container 212 (and the associated conventional chilled water system
(not shown)) may be used to reduce the temperature of the air
passing through the conduit in the closed-loop. Under these
circumstances, a chilled water system that may be located external
to the data center building produces chilled water that is
circulated through container 212. The closed-loop conduit is
submersed in the chilled water and air passing through the
submersed portion of the conduit is thereby further cooled.
[0037] It should be noted that there may be circumstances in which
the water in tank 210 might not be cooler than the pressurized air
in the closed-loop, such as when the system has been running all
day and the outside air is relatively hot. In this instance, once
the sun has set and the external temperature goes down, the
pressurized air may act to reduce the temperature of the water in
tank 210 (so that the water acts, in essence, as a thermal
capacitor that stores cooling energy at night and discharges it
during the day).
[0038] Assuming that optional water tank 210 and water container
212 are included, cooling occurs in the following manner.
Pressurized air is driven by a sealed pump (see element 306 of FIG.
3) through a portion of the closed-loop which is submersed in tank
210 and then through container 212, which lowers the temperature of
the pressurized air therein. The cooled pressurized air is then
distributed to each server in each server rack 202 (and 204).
[0039] The server includes an input port and output port (see, for
example, FIGS. 3 and 4) that are connected to a heat sink which is
mounted in thermal contact with the processor(s) in the server (as
described above, "thermal contact" refers to either direct thermal
contact or close proximity such that heat is removed from the
electronics/processor(s) via conduction and/or convection). Heat
generated by the processor(s) and other heat generating components
is transferred to the pressurized air in the closed-loop, which is
driven out of the server by the sealed pump(s). The heated
pressurized air is then directed to heat exchangers 208, which may
be located on roof 216 of data center 200. Heat exchangers 208
remove heat from the pressurized air in the closed-loop, thereby
reducing the temperature of the pressurized air back to an ambient
level.
[0040] Data center 200 of the present invention provides many
advantages over data center 100, including a significantly reduced
demand for electricity (due, in large part, to the elimination or
reduction of the compressors in the air conditioners and the
blowers in the server racks), significantly reduced noise (due to
the elimination of the blowers) and more effective method of
providing the necessary cooling. The closed-loop pressurized air
system is capable of removing more heat from the data center more
effectively because it is in direct thermal contact with the main
heat generating components, the processor(s), as opposed to passing
a large quantity of cooling air through server rack 102, most of
which has virtually no contact with the heat generated by the
processor(s).
[0041] Persons skilled in the art will appreciate that the present
invention may also be accomplished, albeit in a somewhat less
effective manner, by utilizing the closed loop pressurized air
cooling system shown in FIG. 2, modified in such a way that each
server rack 202 is provided with an air-to-air heat exchanger
(similar to, but smaller than heat exchangers 208). Under these
circumstances, server racks 202 would include the blowers described
previously with respect to data center 100 of FIG. 1 instead of the
heat sinks described herein.
[0042] While this configuration may be less effective at removing
heat from the processors in server racks 202 than heat sink in
thermal contact with the closed loop, this configuration does
provide the advantages of eliminating the need for a water loop
and/or vapor-compression air conditioning system used in
conventional data centers. This configuration may be more practical
for use with existing data centers in which servers cannot be
easily modified for use with processor heat sinks. Moreover, by
utilizing this configuration of the present invention, data center
operators would be able to migrate to the heat sink/thermal contact
configuration as such servers became commercially available,
because the closed loop pressurized air system would already be in
operation.
[0043] FIG. 3 is an illustrative schematic of the present invention
as it is applied to a single server in a server rack. In addition,
FIG. 3. shows an additional advantage of the present invention
whereby heat from the heated pressurized air is used to produce
back-up electrical energy in the event of a fluctuation in primary
power.
[0044] Data center 300, which is constructed and operated in
accordance with the principles of the present invention, includes
server 302 (mounted in server rack 318), heat exchanger 304, sealed
pump 306, air supply 308, optional water holding tank 310, optional
chilled water container 312, processor heat sink 314 and optional
turbine-based back-up energy subsystem 316. Cooling resources are
provided to server 302 in a manner similar to that described
previously with respect to data center 200.
[0045] In the event of a disruption in primary power, in which case
energy subsystem 316 draws off a portion of the heated pressurized
air, the closed-loop of pressurized air is maintained by air supply
308. In all circumstances, the pressurized air is circulated
through the system by sealed pump 306. Pressurized air having a
relatively ambient temperature is passed through conduit submerged
in water tank 310 and then through submerged conduit in chilled
water container 312, after which it enters server rack 318 and is
directed to an input port (not shown) on server 302. The
pressurized air then passes through heat sink 314 (which is in
thermal contact with the processor(s) and other heat generating
components, such as power converters, in server 302) which raises
the temperature of the pressurized air and lowers the temperature
of the processor(s) and associated components.
[0046] The heated pressurized air then passes through valve 320 and
on to heat exchanger 304 which is preferably installed exterior to
physical building 322 that houses most of the components of data
center 300. Moreover, while sealed pump 306 is shown exterior to
building 322, persons skilled in the art will appreciate that
sealed pump 306 may be installed at any location in the
closed-loop, regardless of whether the location is inside or
outside building 322.
[0047] Persons skilled in the art will appreciate that valve 320
could instead be located on the input-side of heat sink 314, in
which case turbine 316 would be driven by relatively cool air
instead of heated air. During a fluctuation in primary power, the
otherwise closed-loop circulates pressurized air to cool server 302
while air in tank 308 is supplied to compensate for any system air
used to drive turbine 316. Under these circumstances, the exhaust
air from turbine 316 would be particularly cool which would help to
cool server 302 and any other heat generating components in server
rack 318.
[0048] In the event of a fluctuation in primary power to data
center 300, valve 320 may be opened to direct some portion of the
heated pressurized air to turbine-based back-up energy system 316.
The heated pressurized air causes the turbine to operate which
drives a generator (which is a part of system 316) to produce
short-term back-up energy. In addition, energy system 316 may also
include an extremely short-term energy storage device, such as a
capacitor (once again, within system 316), which can provide
bridging power to server 302 for the interim period prior to the
turbine reaching operational status.
[0049] The advantages of data center 300, in addition to the
previously described advantages with respect to data center 200,
are related to the addition of an energy back-up system that needs
no additional system resources to operate. The "fuel" to drive the
turbine--hot pressurized air--is a normal by-product of the cooling
system of data center 300. Moreover, as shown in FIG. 5 (and
described below), a back-up energy system 316 for each server rack
318 can be configured and installed just like any other
rack-mounted equipment.
[0050] This also provides the additional advantage of ease of
scalability of the data center. Instead of having to add new air
conditioning units and additional back-up batteries, etc., each new
server rack is installed with its own back-up energy system. In
addition, because each additional server uses significantly less
cooling resources, cooling for many more servers can be provided by
the system before an additional heat exchanger is needed (and the
addition of a heat exchanger is significantly less expensive to
purchase and operate than an air conditioner).
[0051] FIG. 4 shows an illustrative three-dimensional diagram of a
heat sink 402 constructed in accordance with the principles of the
present invention that is mounted in thermal contact with processor
418 (which has connection pins 420). Heat sink 402 includes an
input port 404 and an output port 406, as well as cross-linked
passages 408-416 (persons skilled in the art will appreciate that
the specific configuration of the heat sink is a matter of choice,
provided that the heat sink is in thermal contact with the
processor, and that the heat sink maintains the integrity of the
"closed-loop"). For installation/ accessibility convenience, input
port 404 and output port 406 may be coupled to similar ports on the
back of each rack-mounted server.
[0052] FIG. 5 show a three-dimensional illustrative diagram of a
rack-mounted energy-backup system 500 constructed in accordance
with the principles of the present invention.
[0053] Energy system 500 includes rack-mount drawer 502, turbine
504, generator 506, electronics 508, input port 510 and wires 512.
Rack-mount drawer 502 should be constructed to be the width and
depth of a standard server rack so that it may be easily installed
therein. It may be preferable to mount system 500 in the lower
portion of the server rack, such as the bottom "drawer," since the
height of the rack will likely be larger than a standard server
drawer.
[0054] System 500 operates in accordance with the principles of the
present invention by receiving heated pressurized air via input
port 510. The heated air enters port 510 once the valve (shown in
FIG. 3) is opened. Electronics 508 monitors the quality and
quantity of power being provided to all of the components in the
server rack. In the event that electronics 508 notices a
fluctuation in primary power, electronics 508 sends a signal which
opens the valve (such as valve 320 in FIG. 3) to permit the heated
pressurized air to flow into port 510. In addition, electronics 508
includes an extremely short-term bridging energy device, such as a
capacitor, to provide back-up power for durations lasting less than
the typical one second it takes to start turbine 504.
[0055] Once turbine 504 is spinning at an appropriate speed,
generator 506 will produce short-term back-up power that is
supplied to electronics 508 for distribution to the server rack via
wires 512. In the event of a long-term failure of primary power,
electronics 508 can send a signal to the data center which causes
external, fuel-burning back-up generators (not shown) to come
on-line. These generators can run indefinitely provided that they
are refueled on a regular basis.
[0056] Thus it is seen that a closed-loop pressurized air system
can be used to provide an improved level of cooling resources to a
data center. In addition, the heated pressurized air of the
closed-loop can be used as "fuel" to drive a turbine-based energy
back-up system. Persons skilled in the art will appreciate that the
present invention can be practiced by other than the described
embodiments, which are presented for purposes of illustration
rather than of limitation, and the present invention is limited
only by the claims which follow.
* * * * *