[Title of Invention] COOLING SYSTEM FOR ELECTRONIC DEVICE
STORING APPARATUS AND COOLING SYSTEM FOR ELECTRONIC
s DEVICE STORING BUILDING
[Technical Field]
[OOOl]
The present invention relates to a cooling system for an electronic
10 device storing apparatus and the like, and, more particularly, to a cooling
system for such as an electronic device storing apparatus which cools heat
from a plurality of heating sources such as servers.
[Background Art]
[0002]
15 In recent years, an amount of information processing that is needed
is increasing along with the improvement of information processing
technologies and the development of internet environments. Associated
with such tendency, data center business which installs and operates
equipment such as servers, colnn~unication devices, fixed-line phones and
20 IP (Internet Protocol) telephones that are used for the internet is being paid
attention.
[0003]
A lot of electronic devices such as a computer are installed in a
server room of such a data center. As a method to install electronic
25 devices in a server room, using a rack-mounting systeln is the n~ainstream.
A rack-mounting systeln is a method standardized by JIS (Japanese
Industrial Standards) and EIA (Electronic Industries Alliance), in which
flat type electronic devices are installed in a rack in a stacked manner.
[0004]
2
In order to reserve a space in a server room sufficiently, it is
desired to mount electronic devices into a rack as much as possible.
Therefore, it is needed for electronic devices that the heights of them are
made to be short respectively. Meanwhile, the height of an electronic
5 device such as a 1U (Unit) server and a blade server which are generally
called a rack-mount type server is about 40 millimeters. In order to cool
heat exhausted by such rack-mount type servers, it is necessary to
simultaneously cool a plurality of stacked heat sources having different
heights.
10 [OOOS]
An underfloor air-conditioning system is a general cooling system
for a data center. To cool servers in a data center efficiently, in an
underfloor air-conditioning system, a building in which servers are laid is
made to have double floors, and cool wind from air-conditioning
15 equipment is supplied to server racks from an under floor through a floor
grill, which is provided on a floor surface and is niade of a lnetal plate
havi~lg a plurality of opened holes. This underfloor air-conditioning
system can supply a cool wind to a server rack efficiently because a warn1
air of a server and a cool wind fro111 air-conditioning equipnlent can be
20 separated through double floors.
[0006]
A cooling air volume required for a server rack varies greatly by a
load of a server. Therefore, there is disclosed in patent document 1 a
structure in which a supplied amount of a cold air that is blown out to the
25 front of a rack is controlled according to a heat generation a~nounto f the
rack to reduce motive power for cold air supply and to prevent occurrence
of a hot spot.
[0007]
That is, an average operating rate for each rack is obtained from an
3
operating rate of each server taken in from a control server, the maximum
air volume of a rack is multiplied by the average heat generation amount of
the rack obtained from that value, and, by that, a signal of a required air
volume is generated. Based on this required air volume signal, the
5 nu~liber of rotations of a floor fan of each rack is being controlled.
Furthermore, there is provided a temperature correction arithmetic
processing part to correct a required air volume signal when an inlet
detection temperature of an upper part thermometer provided in a position
corresponding to the inlet of a server exceeds an inlet temperature that has
10 been set.
[0008]
Thus, by obtaining an air volunle required for a server fro111 an
average operating rate of a server rack and a server inlet air temperature of
the uppermost stage of the server rack, a required air volulne and a cool
15 wind temperature of air-conditioning equipment are adjusted according to
a server operating rate which changes every moment and a cool wind
having the most suitable temperature and an air volunle is supplied to each
server.
20 [Citation List]
[Patent Literature]
[0009]
[PTL 11 Japanese Patent Application Laid-Open No. 201 1-226737
25 [Summary of Invention]
[Technical Problenl]
[OOl 01
However, a cooling system in patent document 1 described above
has a problem. That is, this system just supplies an air volume required
4
for servers as a whole by obtaining an average operating rate for each rack
from operating rates of servers. Accordingly, heat control of an
individual server cannot be made even though a generated heat amount is
different depending on each server.
5 [OOl 11
The present invention has been made in consideration of settling
these proble~ns, and its object is to provide a cooling system which can
control the performance of a heat exchanger in more detail.
10 [Solution to Problem]
[OO 1 21
A cooling systeni for an electronic device storing apparatus,
comprising: a rack including an electronic device and a plurality of
placement slielves to place said electronic device; in said rack, a vaporizer
15 having a refrigerant internally being mounted; outside said rack, a
condensing part connected with said vaporizer by a laying pipe being
installed; and a refrigerant adjustment means for adjusting a height of a
refrigerant surface in said vaporizer.
20 [Advantageous Effects of Invention]
[0013]
By a cooling system according to the present invention, a heat
exchanger performance can be controlled in more detail.
25 [Brief Description of Drawings]
[0014]
[Fig. 11 Fig. 1 is a sectional view showing a data center.
[Fig. 21 Fig. 2 is an upper part sectional view showing a data center.
[Fig. 31 Fig. 3 is a front view of a cooling system.
5
[Fig. 41 Fig. 4 is a diagram showing a structure of a mobile tank.
[Fig. 51 Fig. 5 is a diagram showing a cooling system of a second
exemplary embodiment.
[Fig. 61 Fig. 6 is a detail view of a tank fixing plate.
5 [Fig. 71 Fig. 7 is a diagram showing a cooling system of a third
exelilplary embodiment.
[Description of Embodiments]
[0015]
10 Hereinafter, exemplary e~nbodiliients of the present invention will
be described in detail with reference to a drawing. However, although
limitatiol~t hat is tech~~icalldye sirable to implement the present invention
is made to the exemplary embodiments described below, the scope of the
invention is not limited to the followings.
15 [0016]
Fig. 1 is a sectional view showing a data center. In order to cool
servers in a data center 1, a rotary wing of a circulation FAN 10 rotates,
and an outside air is taken in from an air intake opening 2 of the data
center 1. This outside air that has been taken in is absorbed into a server
20 by a FAN inside the server operating. The air absorbed into the server
becomes a warm air by being heated by inner heating elements, and then
exhausted from an air exhaust opening of the server.
[0017]
The warn1 air conducts heat to a refrigerant 16 in a plurality of heat
25 receiving parts installed in a server rack rear surface, and part of the heat
which the warm air has had is absorbed by the refrigerant 16 as a latent
heat when the refrigerant 16 performs a phase change to vapor from liquid.
Then, the temperature of the warm air declines as a result of losing heat.
This warm air is discharged to outside the data center 1 through the
6
circulation FAN 10.
[00 181
Because a partition or the like does not exist around a server rack,
there occurs a so-called short return phenomenon in which part of a warn1
5 air which has not been discharged turns around the server rack 6 and is
supplied to the air intake part of the server rack 6 again.
[00 191
By vapor passing through inside a steam pipe 8, the heat from the
warm air transferred to the refrigerant in a vaporizer 4 is carried to a
10 condenser 5 in a condensing chamber 11 of the data center 1 by buoyancy.
In the condenser 5, the heat of the steam of the refrigerant 16 is carried to
outside air by perfor~ningh eat exchange with the outside air circulated by
a condensation FAN 12 of the condensing chamber 11. On this occasion,
the vapor is condensed into liquid.
15 [0020]
The condensed refrigerant is carried to a tank 13 in the uppermost
part shown in Fig. 3 through a condenser pipe 9. The condensed
refrigerant liquid carried to the tank 13 is supplied to the vaporizer of the
uppernlost stage part through a heat exchanger connecting pipe 14. A
20 tank liquid level rises as a condensed refrigerant liquid goes on being
supplied. However, when the tank liquid level rises to the same height as
the connecting port of a tank connecting pipe 15 connected to the tank 13,
a solvent liquid is connected, not to the heat receiver of the uppermost
stage part, but to the tank 13 in a lower stage through the tank connecting
25 pipe 15. A condensed solvent liquid is supplied into all of a plurality of
pieces of vaporizer 4 by repeating such operations. Exhaust heat of an
electronic device is discharged to outside the data center 1 by the above
cycle.
[0021]
7
Next, action and effect in this exemplary embodiment will be
described with reference to a drawing.
[0022]
First, explanation about how exhaust heat from an electronic device
5 is discharged to outside the data center 1 will be made. In Fig. 1, there is
shown a sectional view of a server rack 6 which stores a plurality of
electronic devices and a data center 1 equipped with a plurality of server
racks. Fig. 2 indicates a top view of the data center 1.
100231
10 As shown in Fig. 1, the air intake opening 2 which takes in an
outside air, the air exhaust opening 3 which discharges the outside air and
the circulation FAN 10 are being installed in the data center 1. A
plurality of pieces of vaporizer 4 having the refrigerant 16 filled inside
them are installed in the rear face, of the server rack 6 arranged in the
15 center part of the data center 1, from the upper part to the lower part of the
server rack 6. It is desirable to provide the vaporizer 4 in a manner
corresponding to each server rack. As shown in Fig. 2, a plurality of
server racks which are constituted by a plurality of servers stacked
vertically are being arranged laterally. A cooling system shown in Fig. 3
20 is provided for each server rack respectively.
COO241
Pieces of temperature sensor 7 for measuring an exhaust
temperature from servers are installed in the server side portions of these
plurality of vaporizers, and pieces of temperature sensor 7 for lneasuring
25 an air temperature after heat exchange are installed in portions of the
vaporizers in the roan1 interior side of the data center 1.
[0025]
A low-boiling-point refrigerant 16 such as hydrofluorocarbon and
hydro-fluoro ether is used as the refrigerant 16 used in the vaporizer 4.
8
The vaporizer 4 is connected to the condenser 5 in the condensing chamber
11 via the steam pipe 8 through which mainly vapor passes to the
condensing chamber 11 provided inside the data center 1. From the
condenser 5, the condenser pipe 9 through which a condensate liquid
5 having phase-changed to liquid from vapor in the condenser 5 passes
con~municates wit11 the vaporizer 4, and thus the vaporizer 4 and the
condenser 5 are connected through the steam pipe 8 and the condenser pipe
9.
[0026]
10 Both of the vaporizer 4 and the condenser 5 are heat exchangers to
perform heat exchange between air and the refrigerant 16, and, for example,
a heat exchanger of a fin and tube type is used. Although not illustrated
in Fig. 1, the colidensing chamber 11 is provided wit11 an air intake opening
and an air exhaust opening, and a condensation FAN which promotes heat
15 exchange between air and the refrigerant 16 is irlstalled in the condenser 5.
[0027]
A plurality of pieces of vaporizer 4 are arrauged vertically as
described above, and the tank 13 that stores the refrigerant 16 is installed
in each vaporizer as shown in Fig. 3. The tank 13 of the vaporizer 4 of
20 the uppermost stage part is connected to the condenser 5 shown in Fig. 1
and Fig. 3 tlirougl~ the condenser pipe 9. The tank 13 are connected
with tile vaporizer 4 through the heat exchanger connecting pipe 14, and
the pieces of tank 13 are connected with each other tl~rough the tank
connecting pipe 15. Meanwhile, a desirable structure is that the heat
25 exchanger connecting pipe 14 is movable or elastic corresponding to an
up-and-down movement of a tank mentioned later. Pieces of steam pipe 8
of respective pieces of vaporizer 4 are brought together to one piece, and
then connected to the condenser 5 as shown in Fig. 3.
[0028]
9
Each piece of tank 13 is installed on and fixed to a mobile plate 17
which can change its height in the vertical direction of the tank 13 as
shown in Fig. 4. This mobile plate 17 moves up and down by corlverting
motive power of a driving machine such as a motor into a force in the
5 vertical direction. Operations of this driving machine are controlled by a
control unit which is not illustrated. Based 011 temperature information
obtained from the temperature sensor 7, the control unit perfornis a tank
up-and-down movement mentioned later and power control of a circulation
fan 10. By the tank 13 operating up and down, a height of the refrigerant
10 16 in the vaporizer 4 ,connected to the tank changes.
[0029]
Next, control of a circulation fan using the temperature sensor 7
and control of the cooling performance of a heat receiving part will be
described. An exhaust air temperature of a server rises by increase of a
15 load of the server in time series. When the exhaust teniperature of a
server is 40 degree C or more, for example, an intake air of a server will
absorb an exhaust air directly due to a short return phenomenon mentioned
above in which an exhaust air of a server turns around the server rack 6.
[0030]
20 Many electronics manufacturers standardize to set the entrance air
temperature of a server to 40 degree C or less, and thus the operational
reliability of a server is damaged if nothing is done. Accordingly, when
the temperature sensor 7 of a heat receiving part in the side of the data
center 1 becomes 40 degree C or more, a control unit performs an operation
25 which makes a driving machine raise a refrigerant height inside the heat
receiving part by making the mobile plate of the tank 13 rise in order to
make cooling perforn~anceo f the heat receiving part be improved.
[0031]
When a refrigerant height is made to rise, heat exchange becomes
10
easy as a result of using a whole heat receiving part, and the exhaust
temperature that has become 40 degree C or more becomes 40 degree C or
less by enhanced heat exchange. At the same time, the control unit
reduces motive power o f the circulation FAN 10 to make a short return
5 mentioned above be easy to occur. Although the entrance air temperature
o f a server goes on rising when a short return is caused, a rise o f the
entrance air temperature o f the server is suppressed because heat exchange
has become easy to be performed at the same time.
[0032]
10 However, cooling performance o f a heat exchanger has its own
limitation. Such cooling performance can be expressed in a te~nperature
difference (AT) between the temperature sensor 7 in the server side and the
te~nperature sensor 7 in the data center 1 side. When a telnperature rise
inside a server is 10 and AT mentioned above is 5 degree C, for example,
15 cooling performance is said that 50% o f heat is being absorbed. The
maximum value o f this AT is decided by the area and the thickness o f a
heat exchanger. Accordingly, decline o f motive power o f the circulatio~l
FAN 10 mentioned above is controlled by a co~ltrol unit such that it is
co~iducted until the perforlnance o f the heat exchanger reaches the
20 luaximu~nv alue o f AT.
[0033]
Many servers have a standard value o f 15 degree C for an intake air
temperature o f a server also in the low temperature side. It1 the case o f
midwinter, an outside temperature o f the data center 1 becomes 15 degree
25 C or less, and thus it is ~iecessityt o heat air in order to make the intake air
temperature o f a server be no s~nallert han 15 degree C. In this case, heat
generation o f a server itself is used. When the temperature o f the
temperature sensor 7 in the data center 1 side is no more than 15 degree C,
the control unit makes the mobile plate o f the tank 13 descend.
11
[0034]
By this movement, a liquid level inside the heat receiving part is
declining. When a liquid level declines, heat exchange is suppressed
because an area where a heat receiving part is filled with the refrigerant 16
5 goes on becoming smaller. The descent of this liquid level is made until
the refrigerant 16 inside the heat receiving part disappears. Around the
same time with this movement of the mobile plate, the control unit makes
the motive power of the circulation FAN 10 goes on being lowered.
When the motive power of the circulation FAN 10 is declining, an intake
10 air temperature of the server is rising because an amount of an exhaust air
of the server that is supplied to an intake air of the server directly goes on
increasing by a short return lnentioned above. At the time point when an
intake air temperature of the server becomes 15 degree C, decline of the
motive power of the circulation FAN 10 is stopped and it is operated at the
15 motive power at that ti~ne.
[0035]
An effect by the above-lilentioned action exists in a point that
temperature control can be performed for each server to which a vaporizer
is provided because the performance of an individual evaporator can be
20 controlled. In addition, temperature control is made by controlling a
movement which is an up-and-down movement of a tank that is easy to be
controlled, and thus the system is not complicated.
[0036]
Next, the second exemplary embodiment will be described using a
25 drawing. Structures overlapping with the first exemplary embodiment
are omitted. A difference from the first exelnplary embodiment in the
second exemplary embodiment is a point that a rnechanisln to adjust a
liquid level of the tank 13 is carried out by a tank fixing plate 18, not by
the mobile plate 17, as shown in Fig. 5. A plurality of pieces of tank
12
fixing plate 18 are connected to a side face of a vaporizer. As shown in
Fig. 6, the tank fixing plate 18 has a hollow cutout enabling to fix the tank
13. As shown in Fig. 5, adjustment of a liquid level of a heat receiving
part is performed by varying a position to mount the tank 13 in the vertical
5 direction among a plurality of pieces of tank fixing plate 18.
[0037]
In the case of the second exemplary embodiment, it is necessary to
move the tank 13 optionally by a human hand, and, thus, detailed control of
a liquid level and the circulation FAN 10 corresponding to a load of a
10 server as is the case with the first exemplary enlbodiment cannot be
realized. Therefore, it is necessary to decide positions of the tank 13 in a
high temperature period in summer and a low temperature period in winter,
for example, in advance, and move the tank 13 beforehand. Effects are
similar to those of the first exemplary embodiment.
15 [0038]
Next, the third exemplary embodiment will be described using a
drawing. Structures overlapping with the first exemplary embodiment
are omitted similarly. A difference from the first exemplary embodiment
in the third exemplary embodiment is a point that a n~echanisnlt o adjust a
20 liquid level of the tank 13 is realized by a fluid control valve 19 as shown
in Fig. 7. In the tank 13, there are provided a plurality of pieces of fluid
control fluid control valve 19 in the vertical direction of the tank 13.
When it is desired to make a liquid level of a heat receiving part rise, by
opening the fluid control valve 19 of the uppern~ost part shown in Fig. 7
25 and by closing the remaining two pieces of fluid control valve 19, for
example, a condensate liquid reaches the tank 13 in a lower stage when the
liquid level reaches the fluid control valve 19 of the uppermost part.
In this exenlplary embodiment, control of a liquid level of a heat
13
receiving part is performed by control of the fluid control valve 19, not by
a form according to an up-and-down movement of the mobile plate 17.
Regarding control of a valve, a control unit can carry out control of a valve
automatically according to temperature information from a temperature
5 sensor just like the first exelnplary embodiment. Alternatively, a valve
may be adjusted by human hands as is the case with the second exe~nplary
embodiment.
[0040]
This application claims priority based on Japanese application
10 Japanese Patent Application No. 2012-264430, filed on Dec. 3, 2012, the
disclosure of which is incorporated liereit1 in its entirety.
[Industrial Applicability]
[0041]
The present invention relates to a cooling system for such as an
electronic device storing apparatus, and, more particularly, to a cooling
system for such as an electronic device storing apparatus which cools heat
from a plurality of heating sources such as a server.
20 [Reference signs List]
[0042]
1 Data center
2 Air intake opening
3 Air exhaust opening
25 4 Vaporizer
5 Condenser
6 Server rack
7 Temperature sensor
8 Steam pipe
14
9 Condenser pipe
10 Circulation FAN
11 Condensing chamber
12 Condensation FAN
5 13 Tank
14 Heat exchanger connecting pipe
15 Tank connecting pipe
16 Refrigerant
17 Mobile plate
10 18 Tank fixing plate
19 Fluid control valve

CLAIMS
1. A cooling system for an electronic device storing apparatus,
comprising: an electronic device, a rack including said electronic device
and a plurality of placement shelves to place said electronic device; in said
5 rack, a vaporizer having a refrigerant internally being mounted; outside
said rack, a condensing part connected with said vaporizer by a laying pipe
being installed; and a refrigerant adjustment means for adjusting a height
of a refrigerant surface in said vaporizer.
2. The cooling system of an electronic device storing apparatus
10 according to claitn 1, wherein a tank to store a refrigerant is provided in a
vaporizer of said heat exchanger.
3. The cooling system of an electronic device storing apparatus
according to claim 2, wherein said refrigerant adjustment means for
adjusting a height of a refrigerant surface has a means for controlling a
15 height of said tank.
4. The cooling syste~no f an electronic device storitig apparatus
according to claim 2, wherein said refrigerant adjustment means for
adjusting a height of a refrigerant surface is provided with a plrrrality of
fluid control devices each being connected to said condensing part and
20 being connected to a different height of said tank.
5 The cooling system of an electronic device storing apparatus
according to any one of claims 1 to 4, comprising a temperature sensor to
detect temperature of said rack; and, according to a detection result of said
temperature sensor, controlling said refrigerant adjustment nieans for
25 adjusting a height of said refrigerant surface.
6 . A cooling system of an electronic device storing building,
comprising: a rack including an electronic device and a plurality of
placement shelves to place said electronic device; said rack being arranged
in a building storing a plurality of said racks; in said building, a plurality
of air intake openings and air exhaust openings to take in and exhaust an
outside air being installed; in said rack, a vaporizer having a refrigerant
internally being mounted; outside said rack, a conclensing part connected
with said vaporizer by a laying pipe being installed; and a refrigerant
5 adjustnlent nlealls for adjusting a height of a refrigerant surface in said
vaporizer.
7. The cooling systenl of an electronic device stori~igb uildilig
according to claim 6, wherein a fan is provided in an air exhaust opening of
said electrollic device storing building.
10 8. The cooling system of an electronic device storing building
according to claim 6 or 7, wherein a temperature sensor to detect
tenlperature of said rack is provided, and, according to a result of said
teinperaturc sensor, output of said fan of said electroliic device storing
building and a refrigerant adjustment nleans are controlled.