U.S. patent application number 12/825586 was filed with the patent office on 2010-10-21 for apparatus and method for cooling a space in a data center by means of recirculation air.
This patent application is currently assigned to KYOTOCOOLING INTERNATIONAL B.V.. Invention is credited to Robbert Mees Lodder, Pedro Matser, Wolter Schaap, Marcel Van Dijk.
Application Number | 20100267325 12/825586 |
Document ID | / |
Family ID | 38051948 |
Filed Date | 2010-10-21 |
United States Patent
Application |
20100267325 |
Kind Code |
A1 |
Matser; Pedro ; et
al. |
October 21, 2010 |
Apparatus and Method for Cooling a Space in a Data Center by Means
of Recirculation Air
Abstract
A data center comprising an air humidity- and
temperature-conditioned space where heat producing ICT and/or
telecom equipment is arranged, a heat wheel and means for supplying
recirculation of air heated by the equipment as a first air stream
to the heat wheel and the heat wheel being configured to cool the
first air stream using a separate second air stream.
Inventors: |
Matser; Pedro; (Hoogland,
NL) ; Van Dijk; Marcel; (Spijkenisse, NL) ;
Lodder; Robbert Mees; (Den Hoorn (ZH), NL) ; Schaap;
Wolter; (Voorst, NL) |
Correspondence
Address: |
SWANSON & BRATSCHUN, L.L.C.
8210 SOUTHPARK TERRACE
LITTLETON
CO
80120
US
|
Assignee: |
KYOTOCOOLING INTERNATIONAL
B.V.
Schiedam
NL
|
Family ID: |
38051948 |
Appl. No.: |
12/825586 |
Filed: |
June 29, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12124697 |
May 21, 2008 |
7753766 |
|
|
12825586 |
|
|
|
|
PCT/NL2007/050435 |
Sep 6, 2007 |
|
|
|
12124697 |
|
|
|
|
Current U.S.
Class: |
454/184 |
Current CPC
Class: |
F24F 2203/104 20130101;
H05K 7/20745 20130101 |
Class at
Publication: |
454/184 |
International
Class: |
H05K 5/02 20060101
H05K005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 6, 2006 |
NL |
1032450 |
Claims
1. A data center, comprising: an air humidity- and
temperature-conditioned space in a building where heat producing
ICT and/or telecom equipment is arranged, the ICT and/or telecom
equipment having an operating temperature; and a data center
cooling means, the data center cooling means comprising a
substantially sensible only air to air heat exchange cooling a
first re-circulated air stream heated by the equipment to a cooling
temperature at or below the operating temperature using a second
separate airstream at a temperature less than or equal to the
cooling temperature minus a predetermined temperature difference
without any additional cooling device, the data center cooling
means comprising no refrigerant or liquid-based cooling, wherein
the data center cooling means is configured to cool the first
re-circulated air stream to the cooling temperature without any
additional cooling device whenever the second air stream
temperature is less than or equal to the cooling temperature minus
the predetermined temperature difference.
2. The data center of claim 1, further comprising means supplying
the first re-circulated air stream cooled by the air to air heat
exchanger to the equipment separately from the first re-circulated
air stream heated by the equipment.
3. The data center of claim 1, wherein the second air stream is
supplied from outside the conditioned space.
4. The data center of claim 1, wherein the second air stream is
outside air.
5. The data center of claim 1, wherein the air to air heat
exchanger comprises a heat wheel, the heat wheel comprising a
plate-shaped heat exchange body which moves successively through
the first re-circulated air stream and the second air stream.
6. The data center of claim 5, wherein the heat wheel extends
through a partition between two chambers, through which chambers
the first re-circulated air stream and the second air stream,
respectively, are guided.
7. The data center of claim 1, wherein a flow rate of the first
re-circulated air stream is adjustable.
8. The data center of claim 1 wherein the predetermined temperature
difference is about 4.degree. C.
9. The data center of claim 1 wherein the operating temperature is
in a range of 20-25.degree. C.
10. The data center of claim 1 wherein the temperature of the
second air stream is less than or equal to about 18.degree. C.
11. The data center of claim 1 wherein the cooling temperature is
approximately equal to the operating temperature.
12. The data center of claim 1 wherein a difference in temperature
between the first re-circulated airstream heated by the equipment
and the cooling temperature is about 6-12.degree. C.
13. The data center of claim 1 wherein there is substantially no
exchange of moisture between the first re-circulated air stream and
second air stream.
14. The data center of claim 1 wherein the humidity of the first
re-circulated airstream remains substantially unchanged.
15. The data center of claim 1 further comprising an additional
cooling means for supplementing the cooling of the air to air heat
exchanger when the second air stream is at a temperature greater
than the cooling temperature minus the predetermined temperature
difference to cool the first recirculated air stream to the cooling
temperature.
16. The data center of claim 15 wherein the additional cooling
means comprises at least one of soil storage, adiabatic or liquid
cooling.
17. The data center of clam 1 wherein the flow rate of the second
air stream is adjustable.
18. A method of cooling a data center, comprising: providing an air
humidity- and temperature-conditioned space in a building where
heat producing ICT and/or telecom equipment is arranged, the ICT
and/or telecom equipment having an operating temperature; providing
a data center cooling means, the data center cooling means
comprising a substantially sensible only air to air heat exchange
and no refrigerant or liquid-based cooling; supplying a first
re-circulated air stream from the humidity- and
temperature-conditioned space heated by the equipment to the air to
air heat exchanger; supplying a second separate airstream at or
below a select temperature to the air to air heat exchanger, the
select temperature being selected so that the first air stream is
cooled to a cooling temperature at or below the operating
temperature by the air to air heat exchanger without any additional
cooling device, the select temperature being less than or equal to
the cooling temperature less a predetermined temperature
difference; and providing the first airstream cooled to the cooling
temperature to the air humidity- and temperature-conditioned space,
wherein the data center cooling means cools the first re-circulated
air stream without any additional cooling device whenever the
second air stream temperature is less than the select
temperature.
19. The method of claim 18 further comprising changing a flow rate
of the first re-circulated air stream when adding or removing of
ICT and/or telecom equipment from the conditioned space.
20. The method of claim 18 further comprising adjusting a flow rate
of the second air stream as the temperature of the second air
stream changes.
21. The method of claim 18 further comprising separating the cooled
first re-circulated airstream from the heated first re-circulated
airstream.
Description
RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 12/124,697, filed on May 21, 2008,
entitled "Apparatus and Method for Cooling a Space in a Data Center
by Means of Recirculation Air", which is a continuation application
of PCT/NL2007/050435, filed on Sep. 6, 2007, which application
claims the benefit of Netherlands Application Serial No. NL
1032450, filed Sep. 6, 2006, each of which is incorporated herein
by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates to an apparatus and method for cooling
a space in a data center using recirculation air, which space is
air humidity- and temperature-conditioned and in which ICT and/or
telecom equipment is arranged.
BACKGROUND
[0003] Data centers are generally known and usually comprise at
least one space in which ICT and/or telecom equipment is arranged,
such as computer, server or network equipment. For a proper
operation of the equipment, a proper and stable temperature and air
humidity in the space are important. A proper operating temperature
for the equipment is between about 20.degree. C. and about
25.degree. C. and a proper air humidity is between about 45% and
about 55%. In view of the heat production of the ICT and/or telecom
equipment, it is desirable to cool the space in order to keep the
space at a stable temperature and air humidity. A data center is
usually in operation 24 hours a day, seven days a week, and so the
ICT and/or telecom equipment should be cooled practically
continuously. The conditioned spaces in data centers are accessible
to persons, and for that purpose are ventilated.
[0004] To cool the space, it is usually provided with a raised
floor under which a cold air stream is blown. Via apertures in the
floor, the air stream is blown into the space. At the top of the
space, the heated air stream is extracted and, after cooling, the
cooled air stream is again blown under the raised floor. Thus, the
air stream is recirculated in the space.
[0005] The air stream is cooled by means of a cooling unit, usually
a compression cooling unit in which a refrigerant is compressed.
The heated air stream gives off its heat to the refrigerant or to a
cooling liquid functioning as intermediate medium. Usually, water
is utilized as intermediate medium to carry the released heat out
of the space.
[0006] The ICT and/or telecom equipment is usually placed in a
system cabinet. Known system cabinets can be cooled in a vertical
manner or in a horizontal manner. With cooling in a vertical
manner, cold air flow is blown into the system cabinet at the
bottom thereof and then, by fans, transported upwards, along the
way cooling the equipment. A disadvantage is that the cold air
stream heats up gradually, so that the air stream in the upper
region of the system cabinet is warmer than the air stream in the
lower region of the system cabinet. Due to this gradual heat-up of
the air stream in the system cabinet for cooling the equipment,
only a limited amount of equipment can be placed in the system
cabinet, so that not the whole system cabinet can be utilized.
[0007] With cooling in a horizontal manner, the cooled air stream
is passed horizontally through the equipment arranged in the system
cabinet, by means of fans of the ICT and/or telecom equipment. The
heated air stream leaves the system cabinet at the back. A
disadvantage is that the heated air stream of one system cabinet
can mix with the cooled air stream of another system cabinet.
Another disadvantage of horizontal cooling is that cooled air flow
can mix with heated air without cooling any equipment.
[0008] Cooling through recirculation air an air humidity- and
temperature-conditioned space in a data center in which ICT and/or
telecom equipment is arranged, is not done efficiently in the known
manner. Usually, the air stream is cooled to a temperature that is
considerably lower than the operating temperature. Furthermore, use
is made of relatively complex cooling units, and cooling involves
much loss. As a consequence, much energy is required and the
electricity costs of a data center are high. Especially in the case
of a large data center, the costs of energy consumption
consequently account for a considerable part of the total
operational costs of the data center. Since the refrigerant is
typically a propellant, in case of leakage of the refrigerant from
the cooling unit, propellant may end up in the atmosphere, causing
an environmental impact. Moreover, as a consequence of the use of
water to dissipate the released heat from the space, water conduits
are present in the space. These might start to leak and then
constitute a danger to the ICT and/or telecom equipment arranged in
the space.
[0009] The object of the invention is to provide an apparatus of
the type mentioned in the opening paragraph hereof which, while
maintaining the above-mentioned advantages, can obviate the
above-mentioned disadvantages.
SUMMARY
[0010] A first aspect of the invention is a data center comprising
an air humidity- and temperature-conditioned space where heat
producing ICT and/or telecom equipment is arranged, a heat wheel
and means for supplying recirculation of air heated by the
equipment as a first air stream to the heat wheel and the heat
wheel being configured to cool the first air stream using a
separate second air stream.
[0011] The claimed invention is based on the insight that for
cooling recirculation air in a data center, it is specifically a
heat wheel, i.e. an air-to-air heat exchanger of the rotary type,
that can be employed successfully. Precisely with the heat wheel, a
sufficiently large cooling capacity can be realized for a data
center, while any leakage surprisingly does not present any
problems for such an application.
[0012] Use of a heat wheel minimizes or eliminates use of complex
cooling units with refrigerant and any intermediate medium, so that
cooling is done more efficiently. This can yield a considerable
saving of energy and hence of costs. Also, the environmental impact
is reduced, because less energy is needed.
[0013] Since the use of refrigerant is minimized or eliminated, the
environmental impact--resulting from leaking propellant--is also
reduced.
[0014] An advantage of the heat wheel as a heat exchange body is
the efficient manner of heat transfer from the first air stream to
the second air stream. Moreover, moisture transport between the
first and the second air stream can be minimal, so that the air
humidity of the first air stream remains approximately equal. For
the practically continuous cooling of the recirculation air in the
space in the data center, a heat wheel can be utilized in a
particularly efficient manner. Further, the temperature of the
cooled first air stream can be approximately equal to the operating
temperature. In a region with a comparable type of climate to the
Netherlands, and when using outside air flow as a second air
stream, the heat wheel, at non-stop operation, can be used for
nearly 80% of the time. Only for the residual 20% may the outside
air stream be too warm and may limited additional cooling be needed
supplemental to the cooling with the heat wheel. It is noted that
within this context a heat wheel is understood to mean an
air-to-air heat exchanger provided with a rotatably arranged,
plate-shaped heat exchange body. The heat exchange body is
preferably substantially of metal. The heat exchange body then
extends preferably through a partition between two air chambers
through which the first and second air stream, respectively, are
guided. The heat exchange body is preferably disc-shaped and may
optionally be provided with perforations. Elegantly, the heat
exchange body may be disposed horizontally. What can thus be
achieved is that the dimensions of the heat exchange body require
no greater construction height than the height of a conventional
story.
[0015] A large cooling capacity can for instance be achieved by
making the heat wheel of large design or by using a plurality of
smaller heat wheels. The rotary speed of a large heat wheel can be
kept low for a considerable part of the time while yet sufficient
cooling capacity can be achieved and leakage can be limited.
[0016] Preferably, the first air stream cooled by the air-to-air
heat exchanger is supplied to the equipment separately from the air
stream heated by the equipment. This prevents the heated first air
stream from mixing with the cooling air, so that the temperature of
the air stream cooled by the air-to-air heat exchanger can be
approximately equal to the desired operating temperature. This
yields a further saving of energy and hence of costs.
[0017] In another advantageous embodiment, the second air stream is
supplied from outside the conditioned space. This can for instance
be air from another space in the data center, or outside air. By
making use, for instance, of outside air, the recirculation air can
be cooled in an advantageous manner.
[0018] The invention further relates to a method for cooling by
means of recirculation air an air humidity- and
temperature-conditioned space in a data center in which ICT and/or
telecom equipment is arranged, and to the use of a heat wheel, for
cooling a recirculation air of an air humidity- and
temperature-conditioned space of a data center in which ICT and/or
telecom equipment is arranged.
[0019] Further advantageous embodiments of the invention are
represented in the claims. The invention will be elucidated with
reference to an exemplary embodiment represented in the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows a schematic view of a space with equipment;
[0021] FIG. 2 shows a schematic view of an air-to-air heat
exchanger designed as a heat wheel; and
[0022] FIG. 3 shows a schematic view of a horizontally configured
heat wheel.
DETAILED DESCRIPTION
[0023] It is noted that the figures are only schematic
representations of a preferred embodiment of the invention that is
described by way of a non limiting exemplary embodiment. In the
figures, like or corresponding parts are designated with the same
reference numerals.
[0024] In FIG. 1 a conditioned space 1 in a data center is shown.
In the space 1, a stable temperature and air humidity prevail.
Preferably, the air humidity is between 45% and 55%. In the space
1, ICT and/or telecom equipment 2 is arranged. The equipment 2
produces heat and is therefore cooled using an air stream that
recirculates in the space 1. Preferably, the operating temperature
of the equipment is between 20.degree. C. and 25.degree. C. For the
purpose of the air recirculation and the cooling, the space 1 is
provided with a raised floor 3.
[0025] The equipment 2 comprises for instance computer, network or
server equipment and is preferably arranged in a system cabinet 14.
In this exemplary embodiment, system cabinets 14 are provided with
a front 4 to which a cooled first air stream is supplied and a back
5 along which a heated first air stream is removed. The equipment 2
has a front 16 facing the front 4 of the system cabinet 14, and a
back 17 facing the back 5 of the system cabinet 14.
[0026] To prevent heated air flow from mixing with the cooled first
air stream, the system cabinets 14 have their fronts 4 facing each
other, to thereby form a `cold corridor` 6. In this exemplary
embodiment, the cold corridor 6 is closed off with sidewalls and a
ceiling 7, to thereby create a closed space within the space 1, and
to separate the heated first air completely from the cooled first
air stream. The heated first air is cooled by means of a cooling
device 8, and the cooled first air stream is thereupon blown under
the raised floor 3.
[0027] The recirculation of the first air stream in the space 1
proceeds as follows. A cooled first air stream 9 is blown under the
raised floor 3. Adjacent the fronts 4 of the system cabinets 14,
there are apertures in the floor through which the cooled first air
stream 9 is blown. The cooled first air stream 9 is supplied to the
fronts 4 of the system cabinets 14 and in them is drawn to the back
5 by the fans of the equipment 2 arranged in the system cabinets
14. On the way, the equipment 2 is cooled, as a result of which the
cooled first air stream heats up, and the first air stream exits at
the back 5 from the system cabinets 14 as a heated first air stream
10. Upon passing through the system cabinet 14, the cooled first
air stream 9 will have heated up by some 6 to 12.degree. C., on
average, thereby rendered a heated first air stream 10. The heated
first air stream 10 is outside the cold corridor 6 and cannot mix
with the cooled first air stream 9 because of the ceiling 7. As a
consequence, no losses occur and the cooled first air stream 9 can
be presented to the equipment 2 at the operating temperature of the
equipment 2, between 20.degree. C. and 25.degree. C. The cooled
first air stream 9 exiting from an exit opening 19 of the cooling
device 8 is thus supplied separately via a supply duct 15 to the
front 16 of the equipment 2. The heated first air stream 10 is
removed from the space 1 near the ceiling via a discharge duct, not
shown, and is supplied to an inlet opening 18 of the cooling
device. The first air stream thus recirculates in the space 1,
while in this exemplary embodiment the cooled first air stream 9 is
separated from the heated first air stream 10.
[0028] The cooling device 8 is designed as an air-to-air heat
exchanger 8 designed as a heat wheel, to which the heated first air
stream 10 is supplied. In the air-to-air heat exchanger 8, the
heated first air stream 10 is cooled using a separate second air
stream 12. Preferably, as shown in FIG. 1, the second air stream 12
is supplied from outside the space 1. In an advantageous
embodiment, the second air stream 12 is outside air. In the
air-to-air heat exchanger 8, the first air stream 10 and the second
air stream 12 remain separate from each other, and therefore no
mixing or substantially no mixing of first and second air stream
takes place.
[0029] FIG. 2 shows a schematic view of an air-to-air heat
exchanger 8. The air-to-air heat exchanger 8 is provided with a
plate-shaped heat exchange body 13, for instance a substantially
metallic plate with small apertures through which air can move. The
plate can have any shape, but is preferably rectangular or
circular. The heat exchange body 13 may also be designed as a
plate-shaped disc wound from corrugated metal plate.
[0030] The heat exchange body 13 is rotatably arranged and moves
successively through the heated first air stream 10 and the cooler
second air stream 12. The heat exchange body 13 extends through a
partition between two air chambers through which the first air
stream 9, 10, and the second air stream 12, respectively, are
guided. Optionally, brushes may be provided, which prevent air
being passed through the partition along with the heat wheel, so
that leakage can be limited. If desired, optionally, a mixing
chamber may be provided in the partition between the air chambers,
to prevent unwanted exchange between the air streams, such as for
instance moisture entry or moisture loss.
[0031] When the heat exchange body 13 moves through the heated
first air stream 10, the heat exchange body 13 is heated up and the
heated first air stream 10 cools down to a cooled first air stream.
Next, the heated heat exchange body 13 moves through the cool
incoming second air stream 12, as a result of which the second air
stream 12 is heated up to a warm exiting second air stream and the
heat exchange body 13 cools down.
[0032] In a heat wheel, the heat exchange body 13 is designed as a
circular thin metal wheel with small apertures through which air
can move. An advantage of the heat wheel is that moisture transfer
between the first and second air stream can be minimal, so that the
air humidity of the first air stream 9, and hence the air humidity
in the space 1, remains substantially unchanged. The construction
of the heat wheel will not be discussed in more detail here, since
it is well known to those skilled in the art. An example of the
construction of a heat wheel is described in the publication `Hoval
Rotary Heat Exchanger for Heat Recovery in Ventilation Systems` HW
60aE1 11/2002 as available on www.hoval.com of Hovalwerk AG, in
particular on page 8 of the publication.
[0033] If the second air stream 12 is a stream of outside air, it
can for instance be used up to an inlet temperature of 18.degree.
C. for complete cooling of the heated first air stream to
22.degree. C. Since the equipment in the space in the data center
needs to be cooled substantially continuously, and since the
outside air temperature including nights in countries of a climate
type like the Netherlands is lower than 18.degree. C. for an
average 80% of the time, the heat wheel can be deployed for cooling
the data center for as much as 80% of the time without additional
cooling. For the residual 20% of the time, the temperature of the
outside air stream will often be such that additional cooling is
needed. Additional cooling can be realized with any other type of
cooling device 20. In an environmentally friendly manner,
additional cooling can for instance be carried out by means of soil
storage, whereby air is drawn from a cool underground buffer
space.
[0034] Since a cooling device 8 for cooling the first air stream in
a conditioned space 1 in a data center is needed virtually
continuously--24 hours a day, seven days a week--the use of an
air-to-air heat exchanger, and in particular of a heat wheel, is
extremely efficient, as no refrigerant and cooling liquid are used.
Thus, a considerable saving on energy consumption and hence on
electricity costs can be achieved. Also, there is less
environmental impact owing to the absence of an environmentally
unsound refrigerant and owing to the lower energy consumption.
[0035] As long as a cooling demand is substantially unchanged--for
instance in that the same amount of equipment 2 in the space
remains active--and the temperature of the second air stream 12 is
practically unchanged, a flow rate of the first air stream 9 and
the second air stream 12 will likewise remain substantially
unchanged, since the cooling demand depends on the amount of heat
being produced by the equipment 2. Upon a change of the cooling
demand, for instance in that more or less equipment 2 in the space
1 is active, the flow rate of the first air stream 9, 10 can be
changed. If the temperature of the incoming second air stream 12
changes, for instance due to the surroundings becoming hotter or
colder, also the flow rate of the second air stream 12 can be
adjusted. As the flow rate of the second air stream 12 can be
adjusted, it can be ensured that the temperature of the cooled
first air stream 9 remains substantially unchanged. So, the flow
rate of the second air stream 12 depends on the difference in
temperature between the second air stream 12 and the first air
stream 10. The flow rate can then be controlled depending on the
desired temperature of the cooled first air stream, for instance
22.degree. C. The flow rate can for instance be controlled by
adjusting the rotary speed of the heat wheel. In a type of climate
as in the Netherlands, the rotary speed can be low for a large part
of the time.
[0036] As illustrated in FIG. 3 the heat wheel 13 may be arranged
horizontally. When so arranged it may optionally be supported to
prevent bending, for instance using support rollers 21 (which are
not intended to be shown in any specific location relative to the
heat wheel 13).
[0037] It will be clear that the invention is not limited to the
exemplary embodiments represented here. For instance, the cooling
device may be disposed inside the space or outside it, or--as shown
in FIG. 1--partly inside the space and partly outside. Also, the
cooling device may be disposed outside the data center. If the
cooling device is disposed outside the space, the heated first air
stream will for instance be carried to the air-to-air heat
exchanger via a ceiling of the space. The additional cooling by the
cooling device 20 can be done in various ways, for instance by
adiabatic cooling or by means of a conventional liquid cooling.
Such variants will be clear to those skilled in the art and are
understood to be within the scope of the invention as set forth in
the appended claims.
[0038] While the invention has been particularly shown and
described with reference to a number of embodiments, it would be
understood by those skilled in the art that changes in the form and
details may be made to the various embodiments disclosed herein
without departing from the spirit and scope of the invention and
that the various embodiments disclosed herein are not intended to
act as limitations on the scope of the claims. All references cited
herein are incorporated in their entirety by reference.
* * * * *
References