U.S. patent application number 11/371681 was filed with the patent office on 2007-09-13 for system and method for cooling a server-based data center with sub-ambient cooling.
This patent application is currently assigned to Raytheon Company. Invention is credited to Richard M. Weber, William G. Wyatt.
Application Number | 20070209782 11/371681 |
Document ID | / |
Family ID | 38235190 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070209782 |
Kind Code |
A1 |
Wyatt; William G. ; et
al. |
September 13, 2007 |
System and method for cooling a server-based data center with
sub-ambient cooling
Abstract
According to one embodiment of the invention, a cooling system
for heat-generating structures comprises a plurality of heat
exchangers, a structure which directs flow of the fluid coolant
substantially in the form of a liquid to each of the plurality of
heat exchangers, and a structure which reduces a pressure of the
fluid coolant to a pressure at which the fluid coolant has a
boiling temperature less than a temperature of the heat-generating
structures. Each of the plurality of heat exchangers is in thermal
communication with at least one of the heat-generating structures
and has an inlet and an outlet. Thermal energy from the
heat-generating structure causes the fluid coolant substantially in
the form of a liquid to boil and vaporize in each of the plurality
of heat exchangers so that the fluid coolant absorbs thermal energy
from the heat-generating structure as the fluid coolant changes
state.
Inventors: |
Wyatt; William G.; (Plano,
TX) ; Weber; Richard M.; (Prosper, TX) |
Correspondence
Address: |
BAKER BOTTS LLP
2001 ROSS AVENUE
6TH FLOOR
DALLAS
TX
75201-2980
US
|
Assignee: |
Raytheon Company
|
Family ID: |
38235190 |
Appl. No.: |
11/371681 |
Filed: |
March 8, 2006 |
Current U.S.
Class: |
165/76 ;
165/104.31; 165/104.32; 165/104.33 |
Current CPC
Class: |
F28D 2021/0031 20130101;
F28D 15/0266 20130101; F28F 2265/14 20130101; F28C 2001/006
20130101; F28D 2021/0019 20130101; H05K 7/20827 20130101 |
Class at
Publication: |
165/076 ;
165/104.33; 165/104.31; 165/104.32 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Claims
1. A cooling system for heat-generating structures disposed in an
environment having an ambient pressure, the cooling system
comprising: a structure which reduces a pressure of a fluid coolant
to a subambient pressure at which the fluid coolant has a boiling
temperature less than a temperature of the heat-generating
structures; a plurality of heat exchangers, each of the plurality
of heat exchangers in thermal communication with at least one of
the heat-generating structures, each of the plurality of heat
exchangers having an inlet and an outlet, each respective inlet
operable to receive fluid coolant into the respective heat
exchangers substantially in the form of a liquid, and each
respective outlet operable to dispense of fluid coolant out of the
respective heat exchanger substantially in the form of a vapor; a
structure which directs flow of the fluid coolant substantially in
the form of a liquid to each of the plurality of heat exchangers,
thermal energy from the heat-generating structure causing the fluid
coolant substantially in the form of a liquid to boil and vaporize
in each of the plurality of heat exchangers so that the fluid
coolant absorbs thermal energy from the heat-generating structure
as the fluid coolant changes state; and a structure which receives
flow of the fluid coolant substantially in the form of a vapor from
each of the plurality of heat exchangers.
2. The cooling system of claim 1, further comprising: a condensing
heat exchanger fluidly coupled between the structure which directs
flow of the fluid coolant substantially in the form of a liquid to
each of the plurality of heat exchangers and the structure which
receives flow of the fluid coolant substantially in the form of a
vapor from each of the plurality of heat exchangers, the condensing
heat exchange operable to condense the fluid coolant substantially
in the form of a vapor into the fluid coolant substantially in the
form of a liquid.
3. The cooling system of claim 2, wherein the condensing heat
exchanger is a water tower.
4. The cooling system of claim 1, wherein the heat-generating
structures are servers.
5. The cooling system of claim 1, wherein the fluid is water.
6. The cooling system of claim 1, wherein at least some of the
plurality of heat-exchangers are removably coupleable to the
structure which directs flow of the fluid coolant substantially in
the form of a liquid to each of the plurality of heat exchangers
and to the structure which receives flow of the fluid coolant
substantially in the form of a vapor from each of the plurality of
heat exchangers.
7. The cooling system of claim 1, wherein the heat-generating
structures include thermosyphons that receive the thermal-energy
from the heat generating structures, and the plurality of heat
exchangers are operable to receive the thermal energy from the
thermosyphons.
8. The cooling system of claim 1, further comprising: a plurality
of heat exchangers for at least one of the heat-generating
structures; a liquid manifold line coupled to each of the plurality
of heat exchangers for the at least one of the heat-generating
structures, the liquid manifold line operable to: receive fluid
coolant from the structure which directs flow of the fluid coolant
substantially in the form of a liquid to each of the plurality of
heat exchangers, and direct flow of the fluid coolant substantially
in the form of a liquid to each of the plurality of heat exchangers
for the at least one of the heat-generating structures; a vapor
manifold line coupled to each of the plurality of heat exchangers
for the at least one of the heat-generating structures, the liquid
vapor line operable to: receive flow of fluid coolant substantially
in the form of a vapor from each of the plurality of heat
exchangers for the at least one of the heat-generating structures,
and direct flow of the fluid coolant substantially in the form of a
vapor to the structure which receives flow of the fluid coolant
substantially in the form of a vapor from each of the plurality of
heat exchangers.
9. The cooling system of claim 8, wherein the plurality of heat
exchangers are removeably coupleable to the liquid manifold line
and the vapor manifold line.
10. A cooling system for heat-generating structures, the cooling
system comprising: a plurality of heat exchangers, each of the
plurality of heat exchangers in thermal communication with at least
one of the heat-generating structures, each of the plurality of
heat exchangers having an inlet and an outlet, each respective
inlet operable to receive fluid coolant into the respective heat
exchangers substantially in the form of a liquid, and each
respective outlet operable to dispense fluid coolant out of the
respective heat exchanger substantially in the form of a vapor; and
a structure which directs flow of the fluid coolant substantially
in the form of a liquid to each of the plurality of heat
exchangers, thermal energy from the heat-generating structure
causing the fluid coolant substantially in the form of a liquid to
boil and vaporize in each of the plurality of heat exchangers so
that the fluid coolant absorbs thermal energy from the
heat-generating structure as the fluid coolant changes state.
11. The cooling system of claim 10, further comprising: a structure
which reduces a pressure of the fluid coolant to a pressure at
which the fluid coolant has a boiling temperature less than a
temperature of the heat-generating structures.
12. The cooling system of claim 11, wherein the heat-generating
structures are disposed in an environment having an ambient
pressure and the pressure of the fluid coolant is reduced to a
subambient pressure.
13. The cooling system of claim 10, further comprising: a structure
which receives flow of the fluid coolant substantially in the form
of a vapor from each of the plurality of heat exchangers.
14. The cooling system of claim 13, further comprising: a
condensing heat exchanger fluidly coupled between the structure
which directs flow of the fluid coolant substantially in the form
of a liquid to each of the plurality of heat exchangers and the
structure which receives flow of the fluid coolant substantially in
the form of a vapor from each of the plurality of heat exchangers,
the condensing heat exchange operable to condense the fluid coolant
substantially in the form of a vapor into the fluid coolant
substantially in the form of a liquid.
15. The cooling system of claim 13, further comprising: a plurality
of heat exchangers for at least one of the heat-generating
structures; a liquid manifold line coupled to each of the plurality
of heat exchangers for the at least one of the heat-generating
structures, the liquid manifold line operable to: receive fluid
coolant from the structure which directs flow of the fluid coolant
substantially in the form of a liquid to each of the plurality of
heat exchangers, and direct flow of the fluid coolant substantially
in the form of a liquid to each of the plurality of heat exchangers
for the at least one of the heat-generating structures; a vapor
manifold line coupled to each of the plurality of heat exchangers
for the at least one of the heat-generating structures, the liquid
vapor line operable to: receive flow of fluid coolant substantially
in the form of a vapor from each of the plurality of heat
exchangers for the at least one of the heat-generating structures,
and direct flow of the fluid coolant substantially in the form of a
vapor to the structure which receives flow of the fluid coolant
substantially in the form of a vapor from each of the plurality of
heat exchangers.
16. The cooling system of claim 13, wherein at least some of the
plurality of heat-exchangers are removably coupleable to the
structure which directs flow of the fluid coolant substantially in
the form of a liquid to each of the plurality of heat exchangers
and to the structure which receives flow of the fluid coolant
substantially in the form of a vapor from each of the plurality of
heat exchangers.
17. A method for cooling heat-generating structures, the method
comprising: providing a plurality of heat exchangers, each of the
plurality of heat exchangers in thermal communication with at least
one of the heat-generating structures, each of the plurality of
heat exchangers having an inlet and an outlet, each respective
inlet operable to receive fluid coolant into the respective heat
exchangers substantially in the form of a liquid, and each
respective outlet operable to dispense of fluid coolant out of the
respective heat exchanger substantially in the form of a vapor;
reducing a pressure of the fluid coolant to a pressure at which the
fluid coolant has a boiling temperature less than a temperature of
the heat-generating structure; and bringing, through a structure,
the fluid coolant into thermal communication with each of the
plurality of heat exchangers, so that the fluid coolant absorbs
heat from each of the plurality of heat exchangers.
18. The cooling system of claim 17, wherein the heat-generating
structures are disposed in an environment having an ambient
pressure and the pressure of the fluid coolant is reduced to a
subambient pressure.
19. The method of claim 17, further comprising: providing a
plurality of heat exchangers for at least one of the
heat-generating structures; receiving, at a liquid manifold line
coupled to each of the plurality of heat exchangers for the at
least one of the heat-generating structures, the fluid coolant
substantially in the form of a liquid; and directing, from the
liquid manifold line, fluid coolant substantially in the form of a
liquid to each of the plurality of heat exchangers for the at least
one of the heat-generating structures.
20. The method of claim 17, wherein the plurality of heat
exchangers are removably coupleable from the structure.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates generally to the field of cooling
systems and, more particularly, to a system and method for cooling
a server-based data center with sub-ambient cooling.
BACKGROUND OF THE INVENTION
[0002] A variety of different types of structures can generate heat
or thermal energy in operation. To prevent such structures from
over heating, a variety of different types of cooling systems may
be utilized to dissipate the thermal energy, including air
conditioning systems.
SUMMARY OF THE INVENTION
[0003] According to one embodiment of the invention, a cooling
system for heat-generating structures comprises a plurality of heat
exchangers, a structure which directs flow of the fluid coolant
substantially in the form of a liquid to each of the plurality of
heat exchangers, and a structure which reduces a pressure of the
fluid coolant to a pressure at which the fluid coolant has a
boiling temperature less than a temperature of the heat-generating
structures. Each of the plurality of heat exchangers is in thermal
communication with at least one of the heat-generating structures
and has an inlet and an outlet. Thermal energy from the
heat-generating structure causes the fluid coolant substantially in
the form of a liquid to boil and vaporize in each of the plurality
of heat exchangers so that the fluid coolant absorbs thermal energy
from the heat-generating structure as the fluid coolant changes
state.
[0004] Certain embodiments of the invention may provide numerous
technical advantages. For example, a technical advantage of one
embodiment may include the capability to enhance cooling capability
for data centers at a reduced energy consumption. Other technical
advantages of other embodiments may include the capability to
minimize a need for conditioned air in a cooling system. Still yet
other technical advantages of other embodiments may include the
capability to minimize potential impact on a server upon a leak
occurring the in the cooling system.
[0005] Although specific advantages have been enumerated above,
various embodiments may include all, some, or none of the
enumerated advantages. Additionally, other technical advantages may
become readily apparent to one of ordinary skill in the art after
review of the following figures and description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a more complete understanding of example embodiments of
the present invention and its advantages, reference is now made to
the following description, taken in conjunction with the
accompanying drawings, in which:
[0007] FIG. 1 is a block diagram of an embodiment of a cooling
system that may be utilized in conjunction with other
embodiments;
[0008] FIG. 2 is a block diagram of another embodiment of a cooling
system that may be utilized in conjunction with other
embodiments;
[0009] FIGS. 3A and 3B illustrate in a block diagram, a transfer of
thermal energy from a structure to a cooling system, according to
embodiments of the invention;
[0010] FIG. 4 is a block diagram of a cooling system, according to
an embodiment of the invention; and
[0011] FIGS. 5A and 5B illustration a sub-system for transfer of
thermal energy from a structure to a cooling system, according to
an embodiment of the invention.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION
[0012] It should be understood at the outset that although example
embodiments of the present invention are illustrated below, the
present invention may be implemented using any number of
techniques, whether currently known or in existence. The present
invention should in no way be limited to the example embodiments,
drawings, and techniques illustrated below, including the
embodiments and implementation illustrated and described herein.
Additionally, the drawings are not necessarily drawn to scale.
[0013] Conventional server based data centers are usually cooled
with refrigerated air. The American Society of Heating
Refrigerating and Air-conditioning Engineers (ASHRAE) has suggested
organizing server cabinets in rows with cool conditioned-air in the
spaces between every second row. The cool air is drawn through the
front of the cabinets to cool the interior electronics and then
blown out the back and toward the ceiling where it is exhausted.
Further, ASHRAE papers have suggested the use of heat pipes to
concentrate the heat and loop-thermosyphons to take the heat to the
top of individual cabinets. The heat or thermal energy is then
removed from the top of the individual cabinet by the cool
conditioned-air.
[0014] Difficulties can arise with such configurations. For a
modern data center, which could be on the order of 40,000 square
feet (having, for example, 1,300 server cabinets), the cooling
needs could be on the order of 1,000 tons (3513 kW) of
refrigeration, including the ancillary cooling loads (lighting, fan
heat, UPS, etc.). To meet these cooling needs, the refrigerated air
cooling system may require two 500 ton chillers with variable speed
compressors and forty 30 ton chilled water computer room
air-conditioning units. In other words, these systems requires a
lot of energy consumption. Accordingly, teachings of some
embodiments of the invention recognize a cooling system that
efficiently enhances cooling capability for data centers at a
reduced energy consumption. Additionally, teachings of some
embodiments of the invention recognize a cooling system that
minimizes a need for conditioned air. Further, teachings of some
embodiments of the invention recognize a configuration that
minimizes impact on a server upon a leak occurring in the cooling
system.
[0015] FIG. 1 is a block diagram of an embodiment of a cooling
system 10 that may be utilized in conjunction with other
embodiments disclosed herein, namely the embodiments described with
reference to FIGS. 3-5B. Although the details of one cooling system
will be described below, it should be expressly understood that
other cooling systems may be used in conjunction with embodiments
of the invention, including the cooling system 100, described with
reference to FIG. 2.
[0016] The cooling system 10 of FIG. 1 is shown cooling a structure
12 that is exposed to or generates thermal energy. The structure 12
may be any of a variety of structures, including, but not limited
to, electronic components, circuits, computers, and servers.
Because the structure 12 can vary greatly, the details of structure
12 are not illustrated and described. The cooling system 10 of FIG.
1 includes a vapor line 61, a liquid line 71, heat exchangers 23
and 24, a pump 46, inlet orifices 47 and 48, a condenser heat
exchanger 41, an expansion reservoir 42, and a pressure controller
51.
[0017] The structure 12 may be arranged and designed to conduct
heat or thermal energy to the heat exchangers 23, 24. To receive
this thermal energy or heat, the heat exchanger 23, 24 may be
disposed on an edge of the structure 12 (e.g., as a thermosyphon,
heat pipe, or other device) or may extend through portions of the
structure 12, for example, through a thermal plane of structure 12.
In particular embodiments, the heat exchangers 23, 24 may extend up
to the components of the structure 12, directly receiving thermal
energy from the components. Although two heat exchangers 23, 24 are
shown in the cooling system 10 of FIG. 1, one heat exchanger or
more than two heat exchangers may be used to cool the structure 12
in other cooling systems.
[0018] In operation, a fluid coolant flows through each of the heat
exchangers 23, 24. As discussed later, this fluid coolant may be a
two-phase fluid coolant, which enters inlet conduits 25 of heat
exchangers 23, 24 in liquid form. Absorption of heat from the
structure 12 causes part or all of the liquid coolant to boil and
vaporize such that some or all of the fluid coolant leaves the exit
conduits 27 of heat exchangers 23, 24 in a vapor phase. To
facilitate such absorption or transfer of thermal energy, the heat
exchangers 23, 24 may be lined with pin fins or other similar
devices which, among other things, increase surface contact between
the fluid coolant and walls of the heat exchangers 23, 24.
Additionally, in particular embodiments, the fluid coolant may be
forced or sprayed into the heat exchangers 23, 24 to ensure fluid
contact between the fluid coolant and the walls of the heat
exchangers 23, 24.
[0019] The fluid coolant departs the exit conduits 27 and flows
through the vapor line 61, the condenser heat exchanger 41, the
expansion reservoir 42, a pump 46, the liquid line 71, and a
respective one of two orifices 47 and 48, in order to again to
reach the inlet conduits 25 of the heat exchanger 23, 24. The pump
46 may cause the fluid coolant to circulate around the loop shown
in FIG. 1. In particular embodiments, the pump 46 may use magnetic
drives so there are no shaft seals that can wear or leak with time.
Although the vapor line 61 uses the term "vapor" and the liquid
line 71 uses the terms "liquid", each respective line may have
fluid in a different phase. For example, the liquid line 71 may
have contain some vapor and the vapor line 61 may contain some
liquid.
[0020] The orifices 47 and 48 in particular embodiments may
facilitate proper partitioning of the fluid coolant among the
respective heat exchanger 23, 24 , and may also help to create a
large pressure drop between the output of the pump 46 and the heat
exchanger 23, 24 in which the fluid coolant vaporizes. The orifices
47 and 48 may have the same size, or may have different sizes in
order to partition the coolant in a proportional manner which
facilitates a desired cooling profile.
[0021] A flow 56 of fluid (either gas or liquid) may be forced to
flow through the condenser heat exchanger 41, for example by a fan
(not shown) or other suitable device. In particular embodiments,
the flow 56 of fluid may be ambient fluid. The condenser heat
exchanger 41 transfers heat from the fluid coolant to the flow 56
of ambient fluid, thereby causing any portion of the fluid coolant
which is in the vapor phase to condense back into a liquid phase.
In particular embodiments, a liquid bypass 49 may be provided for
liquid fluid coolant that either may have exited the heat
exchangers 23, 24 or that may have condensed from vapor fluid
coolant during travel to the condenser heat exchanger 41. In
particular embodiments, the condenser heat exchanger 41 may be a
cooling tower.
[0022] The liquid fluid coolant exiting the condenser heat
exchanger 41 may be supplied to the expansion reservoir 42. Since
fluids typically take up more volume in their vapor phase than in
their liquid phase, the expansion reservoir 42 may be provided in
order to take up the volume of liquid fluid coolant that is
displaced when some or all of the coolant in the system changes
from its liquid phase to its vapor phase. The amount of the fluid
coolant which is in its vapor phase can vary over time, due in part
to the fact that the amount of heat or thermal energy being
produced by the structure 12 will vary over time, as the structure
12 system operates in various operational modes.
[0023] Turning now in more detail to the fluid coolant, one highly
efficient technique for removing heat from a surface is to boil and
vaporize a liquid which is in contact with a surface. As the liquid
vaporizes in this process, it inherently absorbs heat to effectuate
such vaporization. The amount of heat that can be absorbed per unit
volume of a liquid is commonly known as the latent heat of
vaporization of the liquid. The higher the latent heat of
vaporization, the larger the amount of heat that can be absorbed
per unit volume of liquid being vaporized.
[0024] The fluid coolant used in the embodiment of FIG. 1 may
include, but is not limited to, mixtures of antifreeze and water or
water, alone. In particular embodiments, the antifreeze may be
ethylene glycol, propylene glycol, methanol, or other suitable
antifreeze. In other embodiments, the mixture may also include
fluoroinert. In particular embodiments, the fluid coolant may
absorb a substantial amount of heat as it vaporizes, and thus may
have a very high latent heat of vaporization.
[0025] Water boils at a temperature of approximately 100.degree. C.
at an atmospheric pressure of 14.7 pounds per square inch absolute
(psia). In particular embodiments, the fluid coolant's boiling
temperature may be reduced to between 55-65.degree. C. by
subjecting the fluid coolant to a subambient pressure of about 2-3
psia. Thus, in the cooling system 10 of FIG. 1, the orifices 47 and
48 may permit the pressure of the fluid coolant downstream from
them to be substantially less than the fluid coolant pressure
between the pump 46 and the orifices 47 and 48, which in this
embodiment is shown as approximately 12 psia. In some embodiments,
the pressure controller 51 maintains the coolant at a pressure of
approximately 2-7 psia along the portion of the loop which extends
from the orifices 47 and 48 to the pump 46, in particular through
the heat exchangers 23 and 24, the condenser heat exchanger 41, and
the expansion reservoir 42. In particular embodiments, a metal
bellows may be used in the expansion reservoir 42, connected to the
loop using brazed joints. In particular embodiments, the pressure
controller 51 may control loop pressure by using a motor driven
linear actuator that is part of the metal bellows of the expansion
reservoir 42 or by using small gear pump to evacuate the loop to
the desired pressure level. The fluid coolant removed may be stored
in the metal bellows whose fluid connects are brazed. In other
configurations, the pressure controller 51 may utilize other
suitable devices capable of controlling pressure.
[0026] In particular embodiments, the fluid coolant flowing from
the pump 46 to the orifices 47 and 48 through liquid line 71 may
have a temperature of approximately 55.degree. C. to 65.degree. C.
and a pressure of approximately 12 psia as referenced above. After
passing through the orifices 47 and 48, the fluid coolant may still
have a temperature of approximately 55.degree. C. to 65.degree. C.,
but may also have a lower pressure in the range about 2 psia to 3
psia. Due to this reduced pressure, some or all of the fluid
coolant will boil or vaporize as it passes through and absorbs heat
from the heat exchanger 23 and 24.
[0027] After exiting the exits ports 27 of the heat exchanger 23,
24, the subambient coolant vapor travels through the vapor line 61
to the condenser heat exchanger 41 where heat or thermal energy can
be transferred from the subambient fluid coolant to the flow 56 of
fluid. The flow 56 of fluid in particular embodiments may have a
temperature of less than 50.degree. C. In other embodiments, the
flow 56 may have a temperature of less than 40.degree. C. As heat
is removed from the fluid coolant, any portion of the fluid which
is in its vapor phase will condense such that substantially all of
the fluid coolant will be in liquid form when it exits the
condenser heat exchanger 41. At this point, the fluid coolant may
have a temperature of approximately 55.degree. C. to 65.degree. C.
and a subambient pressure of approximately 2 psia to 3 psia. The
fluid coolant may then flow to pump 46, which in particular
embodiments 46 may increase the pressure of the fluid coolant to a
value in the range of approximately 12 psia, as mentioned earlier.
Prior to the pump 46, there may be a fluid connection to an
expansion reservoir 42 which, when used in conjunction with the
pressure controller 51, can control the pressure within the cooling
loop.
[0028] It will be noted that the embodiment of FIG. 1 may operate
without a refrigeration system. In the context of electronic
circuitry, such as may be utilized in the structure 12, the absence
of a refrigeration system can result in a significant reduction in
the size, weight, and power consumption of the structure provided
to cool the circuit components of the structure 12.
[0029] FIG. 2 is a block diagram of another embodiment of a cooling
system 100 that may be utilized in conjunction with other
embodiments disclosed herein, namely the embodiments described with
reference to FIGS. 3-5B. The cooling system 100 of FIG. 2 may
operate in a similar manner to the cooling system 10 of FIG. 1;
however, the cooling system 100 of FIG. 2 also incorporates an air
removal system 190. For a variety of reasons, unintended air or
other fluids may be introduced into the cooling system 100. For
example, in embodiments operating at sub-ambient pressure, outside
ambient fluid will tend to leak into the sub-ambient system upon a
presence of a leak in the system--that is, from a higher to lower
pressure. Accordingly the cooling system 100 may utilize the air
removal system 190 to remove air or other fluids from the cooling
system 100. The air removal system 190 in the embodiment of FIG. 2
includes an air pump 192, a reclamation heat exchanger 194, an air
trap 196, and a reclamation fill valve 198.
[0030] With reference to FIG. 2, the cooling loop for the cooling
system 100 is similar to the cooling loop for the cooling system 10
of FIG. 1 for example, including a heat exchanger 123, a pump 160,
a liquid line 171, a vapor line 161, an expansion reservoir 142, a
pressure controller 151, and a condenser heat exchanger 141.
However, fluid or air leaks 102 may enter the system at the heat
exchanger 123 of a structure 112 or other location and travel in
the vapor line 161 to the condenser heat exchanger 141. At the
condenser heat exchanger 141, condensed coolant liquid may pass
though while air (and any associated coolant vapor that may be
present therein) may be pumped using air pump 192 to a reclamation
heat exchanger 194. The reclamation heat exchanger 194 may cool the
air/coolant vapor combination, which condenses the vapor from the
air stream being removed from the bottom of the condenser heat
exchanger 141. Coolant separates from the air in a trap 196 while
the air exits through a vent 195. A level switch 197 may be in
communication with a reclamation fill valve 198 to allow the
reclamation fill valve 198 to open when recovered coolant is
present. The recovered coolant may be reintroduced to the loop
through the reclamation fill valve 198 and a conduit in
communication with the pump 146.
[0031] Although one example of an air removal system 190 has been
shown with reference to FIG. 2, other air removal systems may be
used in other embodiments of the invention with more, less, or
alternative component parts. Additionally, although components of
embodiments of cooling system 10 and 100 have been shown in FIGS. 1
and 2, it should be understood that other embodiments of the
cooling system 10 can include more, fewer, or different component
parts. For example, although specific temperatures and pressures
have been described for such one embodiment of the cooling systems
10 and 100, other embodiments of the cooling system 10 and 100 may
operate at different pressures and temperatures. Additionally, in
some embodiments a coolant fill port and/or a coolant bleed port
may be utilized with metal-to-metal caps to seal them. Further, in
some embodiments, all or a portion of the joints between various
components may be brazed, soldered or welded using metal-to-metal
seal caps. Further, in some embodiments, as opposed to utilizing a
reclamation heat exchanger 194, the air/coolant vapor combination
may simply be vented to the atmosphere.
[0032] FIGS. 3A and 3B illustrate in a block diagram, a transfer of
thermal energy from a structure 212 to a cooling system, according
to embodiments of the invention. In FIG. 3A, the heat exchanger 223
has been disposed on an end of a structure 212. In such
embodiments, the heat exchanger 223 may be a thermosyphon, heat
pipe, or other similar device. Although not expressly shown, the
structure 212 may include a variety of features to enhance transfer
of thermal energy to the heat exchanger 223. Fluid is received in a
substantially liquid state through a liquid line 271 and vaporized
in the heat exchanger 223. The fluid exits the heat exchanger 223
in a substantially vapor state to the vapor line 261.
[0033] In FIG. 3B, a plurality of heat exchangers 223 extend
through the structure 212 to enhance a transfer of thermal energy.
In each of the heat exchangers, fluid is received in a
substantially liquid state through a liquid line 271 and vaporized
in the heat exchanger 223. The fluid exits the heat exchanger 223
in a substantially vapor state to the vapor line 261.
[0034] FIG. 4 is a block diagram of a cooling system 300, according
to an embodiment of the invention. The cooling loop for the cooling
system 300 may operate in a similar manner to the cooling loops for
the cooling system 10 of FIG. 1 and the cooling system 100 of FIG.
2, for example, including a heat exchanger 323, a pump 346, a
liquid line 371, a vapor line 361, and a condenser heat exchanger
341. The cooling system 300 may be used to cool a plurality of
structures 312, for example, servers in a data center.
[0035] In operation, components of the each of servers or
structures 312 may generate thermal energy, which is dissipated to
the heat exchanger 312. Each of the heat exchangers 323 of the
servers or structures 312 may interact with a common liquid line
371 and a common vapor line 361. Each of the heat exchangers 323
receives fluid in a substantially liquid state through the liquid
line 371 and vaporizes the fluid in the heat exchanger 323. The
fluid exits the heat exchanger 323 in a substantially vapor state
to the vapor line 361.
[0036] As briefly referenced above in FIGS. 3A and 3B, the heat
exchangers 323 in some embodiments may be disposed on an end of the
server or structure 312, for example, as a thermosyphon, heat pipe,
or other similar device. In other embodiments, the heat exchangers
323 may extend into a portion of the structures 312 to enhance a
transfer of thermal energy. In either of these embodiments, the
server or structures 312 may include a variety of different
features to enhance transfer of thermal energy to the heat
exchangers 323.
[0037] In particular embodiments, the servers or structures 312 may
be located inside a building while the condenser heat exchanger 341
and/or pump 346 may be located outside of a building.
[0038] FIGS. 5A and 5B illustration a sub-system 400 for transfer
of thermal energy from a structure 412 to a cooling system,
according to an embodiment of the invention. The sub-system 400 of
FIGS. 5A and 5B may be used in conjunction with the cooling systems
10, 100, and 300 of FIGS. 1, 2, and 4, or other cooling systems.
The structure 412 is shown as a server tower, which may hold a
plurality of circuit cards assemblies 492 and their associated
chassis 462 on shelves 488 or other suitable components. The
sub-system 400 includes a liquid manifold line 482 in communication
with a liquid line 471 of a cooling system and a vapor manifold
line 484 in communication with a vapor line 461 of a cooling
system. To deliver liquid coolant and receive vapor coolant, the
liquid manifold line 482 and vapor manifold line 484 may be
arranged in a variety of configurations. In particular embodiments,
the liquid manifold line 482 and vapor manifold line 484 may be
vertically disposed in a rear portion of the rack 480.
[0039] One or more electronic chassis 462 may respectively be
plugged into the liquid manifold line 482 and the vapor manifold
line 484 to obtain cooling functionality for the electronic chassis
462. The chassis 462 may have a heat exchanger 423 in its wall,
which contains an inlet port 425 (e.g., for substantial liquid
fluid coolant) and an exit port 427 (e.g., for substantially vapor
fluid coolant) . The inlet port 425 may fluidly couple to the
liquid manifold line 482 and the exit port 427 may fluidly couple
to the vapor manifold line 484 using a variety of fluid coupling
techniques, including but not limited to techniques which utilize
seals, O-rings, and other devices.
[0040] Although the chassis 462 has been described as fluidly
coupling to the liquid manifold line 482 and the vapor manifold
line 484 in the structure 412 in this embodiment, in other
embodiments, the structure 412 may provide a series of coolant
channels or heat exchangers plumbed into the walls of the rack 412,
for example, in a manner similar to that described with reference
to FIG. 3B. Accordingly, each chassis 462 would simply slide into
its allocated slot where it may be coupled or clamped to the
coolant channels or heat exchangers. An advantage of such an
embodiment is that the cooling system may be sealed. Accordingly,
minimized perturbances to such a sealed system would occur during
insertion or removal of a chassis 462.
[0041] Although the present invention has been described with
several embodiments, a myriad of changes, variations, alterations,
transformations, and modifications may be suggested to one skilled
in the art, and it is intended that the present invention encompass
such changes, variations, alterations, transformation, and
modifications as they fall within the scope of the appended
claims.
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