U.S. patent application number 13/201443 was filed with the patent office on 2011-12-08 for electronic equipment cabinet.
Invention is credited to Michael Gee, Shaun Andrew Vosper.
Application Number | 20110297351 13/201443 |
Document ID | / |
Family ID | 42561306 |
Filed Date | 2011-12-08 |
United States Patent
Application |
20110297351 |
Kind Code |
A1 |
Vosper; Shaun Andrew ; et
al. |
December 8, 2011 |
ELECTRONIC EQUIPMENT CABINET
Abstract
There is provided an electronic equipment cabinet including a
cabinet carcass (15) mounting fan cooled equipment (16) venting to
the cabinet rear. A hinged front closure assembly (11) includes a
frame (14) and an outer filter and perforated metal screen assembly
on the outer face of the frame, and a lower condensation trap (20).
The frame 14 supports an evaporator assembly (11) connected to a
remote compressor/condenser assembly (not shown). The evaporator
assembly includes a combined dew point sensor and thermostat (13).
A non-woven filter web (19) acts a micro-droplet catcher on the
inner face of the door assembly.
Inventors: |
Vosper; Shaun Andrew;
(Queensland, AU) ; Gee; Michael; (Queensland,
AU) |
Family ID: |
42561306 |
Appl. No.: |
13/201443 |
Filed: |
November 5, 2009 |
PCT Filed: |
November 5, 2009 |
PCT NO: |
PCT/AU09/01433 |
371 Date: |
August 12, 2011 |
Current U.S.
Class: |
165/67 |
Current CPC
Class: |
H05K 7/20818
20130101 |
Class at
Publication: |
165/67 |
International
Class: |
F28F 9/00 20060101
F28F009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 13, 2009 |
AU |
2009900605 |
Claims
1. An electronic equipment cabinet including: a cabinet body having
a ventilated rear wall and a front opening providing access to rack
mounted equipment within the cabinet of the type having an integral
cooling fan venting through said ventilated rear wall; a ventilated
front closure assembly adapted to selectively close said front
opening and including an air-to-coolant heat exchange panel and an
air filtration medium adjacent the heat exchange panel on the
equipment side thereof; and forming a continuous air flow path from
outside of the cabinet body through the ventilated front closure,
said rack mounted equipment and said ventilated rear wall; and heat
pump means connected to said heat exchange panel and operable to
thermally condition air passing through said air flow path.
2. Air conditioning apparatus according to claim 1, wherein the
heat exchange panel and heat pump means are selected to condition
air for cooling purposes.
3. Air conditioning apparatus according to claim 1, wherein the air
filtration medium is selected from woven or non-woven
materials.
4. Air conditioning apparatus according to claim 1, wherein there
is provided a condensation collection tray at the foot of the
panel.
5. Air conditioning apparatus according to claim 1, wherein there
is provided air curtain means adapted to pass air vertically
downward across the face of the heat exchanger panel.
6. Air conditioning apparatus according to claim 1, wherein the air
curtain means is provided by a header fan assembly comprising
housing for a barrel fan impeller and having a directional slot
directing an air curtain across the face of the heat exchanger
panel.
7. Air conditioning apparatus according to claim 1, wherein said
support means includes a racking arrangement mounted within an
equipment cabinet.
8. Air conditioning apparatus according to claim 1, wherein the
front closure assembly includes a frame member defining a front
aperture into which is mounted the heat exchange panel.
9. Air conditioning apparatus according to claim 1, wherein the
front closure assembly is removably secured to the cabinet.
10. Air conditioning apparatus according to claim 1, wherein the
front closure is hinged to the cabinet in the form of a door.
11. Air conditioning apparatus according to claim 10, wherein the
equipment is stacked vertically in 19'' (480 mm) standard equipment
racks in standard metal cabinets, wherein the front closure
replaces the standard cabinet front door.
12. Air conditioning apparatus according to claim 1, wherein the
heat exchange panel includes separately cooled zones corresponding
to the position of respective equipment items.
13. Air conditioning apparatus according to claim 1, wherein the
heat exchange panel is associated with one or more of filters
including HEPA filters, adsorbents, and the like.
14. Air conditioning apparatus according to claim 1, wherein the
heat exchange panel and heat pump in assembly is selected from one
or more of solid state cooling devices, Carnot cycle heat pump,
phase change regenerative cooling and Siemens cycle heat pump.
15. Air conditioning apparatus according to claim 14, wherein the
heat exchange panel comprises the evaporator unit or reverse cycle
evaporator/condenser unit of a conventional refrigeration
plant.
16. Air conditioning apparatus according to claim 15, wherein the
heat exchanged by the heat exchanger panel is conveyed for remote
disposal or recovery.
17. Air conditioning apparatus according to claim 15, wherein the
radiator of the heat pump may be co-located with the heat exchange
panel and coupled to a heat disposal exchanger cooled by air or
liquid coolant.
18. Air conditioning apparatus according to claim 16, wherein
conventional refrigeration plant is used, and the heat exchange
panel is connected in circuit with a remote compressor/condenser
assembly.
19. Air conditioning apparatus according to claim 15, wherein said
heat pump comprises remote refrigeration plant of single head or
multi-head design to drive a single or multiple said heat exchange
panels respectively.
20. Air conditioning apparatus according to claim 15, wherein the
heat exchange panel is associated with control means for monitoring
and controlling the heat pump.
21. A method of temperature-controlling electronic equipment of the
type having a native thermal regulating air flow, including
supporting the equipment relative to a heat exchange panel having a
heat exchanging air flow path therethrough, and operating heat pump
means connected to said heat exchange panel to thermally condition
air passing through said heat exchanging air flow path, whereby
temperature regulating air is drawn by said native thermal
regulating air flow from said heat exchanging air flow path.
Description
FIELD OF THE INVENTION
[0001] This invention relates to an electronic equipment cabinet.
This invention has particular application to an electronic
equipment cabinet for controlling the temperature environment for
electronic equipment rack mounted within the cabinet, and for
illustrative purposes the invention will be described with
reference to this application. However we envisage that this
invention may find use in other applications such as environment
conditioning of cabinets and enclosures generally.
BACKGROUND OF THE INVENTION
[0002] The reference to any prior art in this specification is not,
and should not be taken as, an acknowledgement or any form of
suggestion that the referenced prior art forms part of the common
general knowledge in Australia or elsewhere.
[0003] Many data processing centres are configured around
microprocessor-based, standard rack-mounted equipment adapted to be
mounted in metal racks within ventilated, generally metal cabinet
enclosures. A typical data processing centre will have ranks of
cabinets. Microprocessor based equipment and the associated hubs,
hard drive and other NAS devices are generally configured to be air
cooled, with integral fans and a generally front to rear air flow
path through the equipment. The equipment is thereby rendered
independent of the types of cooling systems required for mini- and
mainframe computer hardware. This independence from connectable
cooling means that control of the condition of the air within the
building space environment containing a data processing centre is
used to provide overall temperature control.
[0004] The dependence on control of the condition of the
environmental air to control the operating temperature has several
disadvantages. The systems are not readily scalable in that the
plant must be engineered to deal with the worst case peak thermal
load and temperature differential. There is a basic cost for idling
capacity below the peak load. More importantly, environmental air
control imposes planning geometry on the space to avoid hot spots.
The corollary is that there is a risk of certain cabinets getting
less than optimal cooling air.
[0005] A proprietary system of Sun Microsystems Inc provides more
efficient rack cooling than standard datacenter cooling systems to
significantly reduce energy consumption and increase effective
compute density by up to 70 percent over in-row, environmental
cooling options. The system comprises a cold water or refrigerant
chilled rear door to the SUN BLADE 6048 modular system. It is a
passive design that does not require additional fans or electrical
power to function. The cooling system removes heat from the exhaust
air blade unit exhaust air and requires minimal data centre
footprint. Up to 35 kW of cooling capacity per door is available, a
considerable increase over traditional raised floor cooling. The
system is configured with humidity sensor-mediated thermostatic
control to ensure that air exiting the system is not cooled below
2.degree. C. above the dew point.
[0006] This system is specifically tailored to its proprietary Sun
Microsystems environment. There is a need for a more generalized
solution. It is especially not suited to installations of
CISCO.RTM. switches, where lack of control of the incoming air may
cause a DPS shutdown.
SUMMARY OF THE INVENTION
[0007] In one aspect the present invention resides broadly in an
electronic equipment cabinet including: [0008] a cabinet body
having a ventilated rear wall and a front opening providing access
to rack mounted equipment within the cabinet of the type having an
integral cooling fan venting through said ventilated rear wall;
[0009] a ventilated front closure assembly adapted to selectively
close said front opening and including an air-to-coolant heat
exchange panel and an air filtration medium adjacent the heat
exchange panel on the equipment side thereof; and forming a
continuous air flow path from outside of the cabinet body through
the ventilated front closure, said rack mounted equipment and said
ventilated rear wall; and [0010] heat pump means connected to said
heat exchange panel and operable to thermally condition air passing
through said air flow path.
[0011] In most cases, the heat exchange panel and heat pump means
will be selected to condition air for cooling purposes, and for the
purposes of description of the invention this function will be
emphasized. However, it must be envisaged that under certain
circumstances it may be desirable to condition the air to heat
equipment to an optimum operating temperature. This heating may be
part of a controlled cycle including cooling functions, wherein the
transitions between heating and cooling are managed by operation of
a reverse-cycle heat pump or desiccated heat pumps driving separate
heat exchange evaporator and condenser units in the heat exchange
panel.
[0012] The air filtration medium may be selected from woven or
non-woven materials. It has been surprisingly determined that, even
with control of operation of a panel by the use of a humidity
sensor, highly localized conditions can promote the formation of
condensation. In the usual usage a filter medium would be located
on the outside of the panel to prevent dust from entering the heat
exchanger panel. However, the location of the air filter medium
adjacent to the heat exchanger panel on the inside not only
prevents dust circulation but prevents occasional instances of
condensation from being entrained in the airflow. The air
filtration medium may comprise an air filtration web mounted on a
frame supported on the inner surface of the ventilated front
closure. Alternatively the air filtration medium may comprise an
air filtration web trapped by a mesh faced frame supported on the
inner surface of the ventilated front closure
[0013] In the event of a failure of environmental air conditioning
resulting in a significant increase in humidity and temperature, or
in the event of an environmental increase in humidity, condensation
may form on the panel. This may be dispersed by diffusion through
the air filter medium or other media facing the panel. There may be
provided a condensation collection tray at the foot of the panel.
The tray may be associated with wicking means do dissipate any
collected water as vapour under non-condensing conditions.
[0014] In preferred embodiments of the present invention there is
provided air curtain means adapted to pass air vertically downward
across the face of the heat exchanger panel. For example there may
be provided a header fan assembly comprising housing for a barrel
fan impeller and having a directional slot directing an air curtain
across the face of the heat exchanger panel. It has been found that
the use of an air curtain in this manner disturbs the air ahead of
the panel and adds some condensation control. This is a surprising
result.
[0015] The equipment may be supported in the cabinet on support
means which may comprise a standard or proprietary racking
arrangement for one or more units of equipment. In certain
embodiments of the present invention, the support means is a
racking arrangement mounted within a metal equipment cabinet. Such
cabinets are usually configured for airflow, having a net flow path
from the front and/or floor and venting to the back and/or top.
[0016] The heat exchange panel may comprise a front closure for a
cabinet housing the support means and the equipment supported
thereby. The front closure may include a frame member defining a
front aperture into which is mounted the heat exchange panel. The
front closure may be removably secured to the cabinet.
Alternatively the front panel may be hinged to the cabinet in the
form of a door. Equipment may be stacked vertically in 19'' (480
mm) standard equipment racks in standard metal cabinets, wherein
the front closure may replace the standard cabinet front door.
[0017] Cabinet closure-forming heat exchange panels have a
particular advantage in that the cooling air inlet vents of the
rack-mounted equipment can be maintained in relatively close
proximity to the heat exchanger. Accordingly the cooling air
passing into the equipment has for the most part passed through
only that portion of the heat exchanger adjacent the equipment. The
heat exchanger may include separately cooled zones corresponding to
the position of the respective equipment items. However, where the
heat exchanger is monolithic, the localization of air flow means
that heat transfer occurs most in the region of the equipment. The
heat is then distributed by the coolant and/or by conduction
throughout the heat exchanger body depending on the cooling method
employed. The effect is one of self regulation where the cooling
effort supplied by the heat exchanger is automatically proportional
to the population of equipment items in the cabinet.
[0018] The heat exchange panel may be associated with other air
conditioning devices such as upstream particulate filters including
HEPA filters, adsorbents, and the like. For example, in cabinet
closure types of heat exchanger panels, the frame may include a
mount for a filter assembly, such as a slide-in mount for a filter
assembly having a bordering frame.
[0019] The heat exchange panel may be selected from any suitable
heat exchange means including but not limited to solid state
cooling devices, Carnot cycle heat pump or phase change
regenerative cooling or Siemens cycle heat pump. For example the
heat exchange panel may comprise the evaporator unit or reverse
cycle evaporator/condenser unit of a conventional refrigeration
plant. The heat exchanged by the heat exchanger panel may be
disposed of the local environment. However, it is preferred that
the heat be conveyed for remote disposal or recovery. For example
the radiator of the heat pump may be co-located with the heat
exchanger and coupled to a heat disposal exchanger cooled by air or
liquid coolant. Where conventional refrigeration plant is used, the
heat exchanger may be connected in circuit with a remote
compressor/condenser assembly.
[0020] Where remote refrigeration plant is used, this may be of the
single head or multi-head design. For example, there may be used a
remote compressor/condenser unit that is capable of operating two
or more heat exchange panels such as the abovementioned cabinet
door units.
[0021] The heat exchange panel may be associated directly or
indirectly with control means for monitoring and controlling the
heat pump activity of the panel. For example, the heat exchange
panel may include thermally conductive parts including a reference
part having a transducer or other sensor mounted thereon. The
sensor may be used to control a TX valve or other suitable scaling
device selected according to the type of heat pump and the
direction of the cycle at the time. Cabinet enclosures or other
housings may include sensors to detect any one of both of
temperature and air flow. In addition or in the alternative, the
operating temperature may be sensed and appropriate control signals
generated by monitoring means associated with the equipment per
se.
[0022] In a further aspect the present invention resides broadly in
a method of temperature-controlling electronic equipment of the
type having a native thermal regulating air flow, including
supporting the equipment relative to a heat exchange panel having a
heat exchanging air flow path therethrough, and operating heat pump
means connected to said heat exchange panel to thermally condition
air passing through said heat exchanging air flow path, whereby
temperature regulating air is drawn by said native thermal
regulating air flow from said heat exchanging air flow path.
[0023] Apparatus in accordance with the foregoing may be powered by
energy efficient means such as direct solar to LV compressor
technology or may be integrated into the grid by conventional
solar-to-inverter technology.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be described with reference to the
following non-limiting embodiment of the invention as illustrated
in the drawings and wherein:
[0025] FIG. 1 is an isometric view of apparatus in accordance with
the present invention;
[0026] FIG. 5 is a plot of air flow through the apparatus of FIG.
1;
[0027] FIG. 6 is; a plot of dew point inside the equipment cabinet
of the air flow through the apparatus of FIG. 1
[0028] FIG. 7 is a plot of air temperature inside the equipment
cabinet of the air flow through the apparatus of FIG. 1;
[0029] FIG. 8 is a plot of high temperature test air temperature
passing into the equipment cabinet of the apparatus of FIG. 1;
[0030] FIG. 9 is a plot of high temperature test air temperature
having passed into the equipment cabinet of the apparatus of FIG.
1; and
[0031] FIG. 10 is a plot of the evaporator core temperature during
the high temperature test of FIGS. 8 and 9.
[0032] In FIG. 1 there is provided an electronic equipment cabinet
including a cabinet carcass 15 mounting rack mounted computer
equipment 16 in a conventional manner. The equipment is fan cooled
and exhaust air 17 exits at the rear of the cabinet 15. A front
closure assembly 11 is hinged by lift-off hinges 12 and is shown in
an open position for servicing the front closure 11 and/or the
racked equipment 16. FIGS. 2-4 illustrate the exploded components
of the front closure 11.
[0033] The front closure assembly 11 is built up on a door frame 14
is supported on the cabinet 15 by the hinges 12. An outer filter
and screen assembly 16 is supported on the outer face of the door
frame and includes a perforated metal protective screen. The lower
edge of the door frame 14 is provided with a condensation trap
20.
[0034] The door frame 14 supports on its inner face an evaporator
assembly 11 connected to a remote, approximately 2 kW heat pump
capacity, compressor/condenser assembly (not shown). The evaporator
assembly includes regulation elements including a combined dew
point sensor and thermostat 13. The suction and delivery lines 18
are connected by flexible lines to enable operation of the door. A
non-woven filter web 19 acts a micro-droplet catcher on the inner
face of the door assembly.
[0035] In use, the equipment 16 rack mounted in the cabinet 15
operates and generates heat. Internal sensors switch internal fans
drawing cooling air from front vents and exhausting air through
rear vents. The fans are thermally switched to save energy.
[0036] FIG. 5 illustrates a data-logged period of time from 2300
hrs to 0541 hrs of an installed stack of equipment having 6 fan
modes in total. Environmental and peak processing load variables
results in a flux of air from front to back of the cabinet. When
all units are at maximum cooling, the maximum velocity V.sub.max
measured through the plane of the door assembly is approximately 23
mmin.sup.-1. The plot of FIG. 5 shows integer air flows being
highest from 2200 to 0200 and lowest from 0200 to the end of the
log, forming in essence two broad cooling states.
[0037] The evaporator assembly 11 is operated under the primary
control of the thermostat 13 and secondary control of the dew point
sensor. FIGS. 6 and 10 indicate an initial state of fluctuating dew
point and temperature under load from start-up at 2300 to 0000, as
the oscillating feedback loop of temperature and dew point operate
the panel. After 0000, an approximate steady state operating
temperature of the evaporator panel per se is reached (FIG.
10).
[0038] The dew point of air on the equipment side of the evaporator
assembly 11 plots an average curve from about 23.8.degree. C. at
0000 to a broad peak of about 25.25 centred about 0300 (FIG. 6).
This is a measure of the absolute moisture content of the
environmental air. Simultaneously, the temperature plot curve of
FIG. 7, measuring the exhaust air temperature from the cabinet,
slowly increases from 30.degree. C. at 2300 to a broad peak of
about 31.1.degree. C. between 0100 and 0200, followed by a steep
decline corresponding exactly to the switching off of 2/3 of the
cooling fans at 0200. The minimum temperature of 28.8.degree. C. is
safely above the dew point at the same time, as is the dew point at
each relevant point of the air temperature plot, despite there
being no direct coupling of the dew point (dependent only on the
environment) and temperature (dependent on both control feedback
and equipment thermal load) plots.
[0039] In FIGS. 8 and 9, there is illustrated the results of a
thermal stress test where hot air is applied to the exterior front
of the evaporator assembly. FIG. 8 is the plot of temperature
against time measured by a probe supported adjacent to but
thermally insulated from the evaporator assembly. The plot shows
that the air temperature increased steeply from start up at just
after 2300 to 60.degree. C. and then increased more or less
smoothly to a plateau of about 68.3.degree. C. At the same time,
the exit air temperature plot of FIG. 9 shows two plateaus, a first
between 0000 and 0200 of about 34.5.degree. C. and a second between
0200 and 0500 of about 33.5.degree. C. These plateaux correspond
exactly to the peak and off-peak processing load cooling
requirements. The comparison indicates that apparatus in accordance
with the present invention can cope with environmental shock such
as long term environmental air conditioning failure.
[0040] It will of course be realised that while the above has been
given by way of illustrative example of this invention, all such
and other modifications and variations thereto as would be apparent
to persons skilled in the art are deemed to fall within the broad
scope and ambit of this invention as is set forth in the claims
appended hereto.
* * * * *