U.S. patent application number 11/941839 was filed with the patent office on 2009-05-21 for telecommunications shelter with emergency cooling and air distribution assembly.
This patent application is currently assigned to Rocky Research. Invention is credited to Kaveh Khalili, Uwe Rockenfeller.
Application Number | 20090126293 11/941839 |
Document ID | / |
Family ID | 40640505 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090126293 |
Kind Code |
A1 |
Khalili; Kaveh ; et
al. |
May 21, 2009 |
TELECOMMUNICATIONS SHELTER WITH EMERGENCY COOLING AND AIR
DISTRIBUTION ASSEMBLY
Abstract
A telecommunications outdoor shelter having an interior chamber
containing one or more vertical racks of telecommunications and/or
electronic components, and an AC powered air conditioner configured
to deliver cooled air to said interior chamber, is characterized by
a back-up cooling apparatus comprising: an outdoor refrigeration
system exterior to the interior chamber configured for supplying
refrigerant or chilled heat transfer fluid to an evaporator mounted
in the interior chamber and for rejecting heat to ambient outside
air; an air cooling unit comprising an air handler and evaporator
mounted in the interior chamber and configured to receive
refrigerant or heat transfer fluid from the outdoor refrigeration
system and provide cool air to the interior chamber; an air
distribution assembly cooperating with the comprising air cooling
unit and one or more primary air ducts for directing cooled air
from the evaporator and a plurality of secondary air ducts
communicating with each of the primary air ducts, wherein each of
the secondary air ducts is configured for delivering cooled air to
one or more selected vertical racks at one or more vertical levels
and wherein the handler includes one or more fans for moving warm
air from the interior chamber to the evaporator and forcing cooled
air through the one or more primary air ducts and the one or more
secondary air ducts; an electric power generating unit configured
to provide power for operating the outdoor refrigeration system and
the indoor air cooling unit; and a sensor configured to initiate
operation of the back-up cooling apparatus in response to AC power
outage and/or interior chamber air temperature.
Inventors: |
Khalili; Kaveh; (Boulder
City, NV) ; Rockenfeller; Uwe; (Boulder City,
NV) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
Rocky Research
Boulder City
NV
|
Family ID: |
40640505 |
Appl. No.: |
11/941839 |
Filed: |
November 16, 2007 |
Current U.S.
Class: |
52/220.1 |
Current CPC
Class: |
E04H 5/02 20130101; H05K
7/2059 20130101 |
Class at
Publication: |
52/220.1 |
International
Class: |
E04C 2/52 20060101
E04C002/52 |
Claims
1. A telecommunications outdoor shelter having an interior chamber
containing one or more vertical racks of telecommunications and/or
electronic components, and an AC powered air conditioner configured
to deliver cooled air to said interior chamber, is characterized by
a back-up cooling apparatus comprising: an outdoor refrigeration
system exterior to said interior chamber configured for supplying
refrigerant or chilled heat transfer fluid to an evaporator mounted
in said interior chamber and for rejecting heat to ambient outside
air; an air cooling unit comprising an air handler and evaporator
mounted in said interior chamber and configured to receive
refrigerant or heat transfer fluid from said outdoor refrigeration
system and provide cool air to said interior chamber; an air
distribution assembly cooperating with said air cooling unit and
comprising one or more primary air ducts for directing cooled air
from said evaporator and a plurality of secondary air ducts
communicating with each of said primary air ducts, wherein each of
said secondary air ducts is configured for delivering cooled air to
one or more selected vertical racks at one or more vertical levels
thereof within said interior chamber, and wherein said handler
includes one or more fans for moving warm air from the interior
chamber to said evaporator and forcing cooled air through said one
or more primary air ducts and said one or more secondary air ducts;
an electric power generating unit configured to provide power for
operating said outdoor refrigeration system and said indoor air
cooling unit; and a sensor configured to initiate operation of said
back-up cooling apparatus in response to AC power outage and/or
interior chamber air temperature.
2. A telecommunications shelter of claim 1 wherein said one or more
primary air ducts are mounted in said interior chamber and extend
generally horizontally above said one or more vertical racks, and
wherein each of said one or more secondary air ducts comprises one
or more distribution outlet ports positioned below a primary air
duct at a vertical level above the upper end of an adjacent
vertical rack.
3. A telecommunications shelter of claim 1 wherein said one or more
primary air ducts comprises a plurality of detachably connected
duct segments.
4. A telecommunications shelter of claim 2 wherein the length of
one or more of said secondary air ducts is adjustable for changing
or selecting a vertical level and/or horizontal location of said
one or more outlet ports.
5. A telecommunications shelter of claim 4 wherein said one or more
secondary air ducts comprises a plurality of disengagable connected
duct segments.
6. A telecommunications shelter of claim 2 wherein at least one of
said secondary air ducts comprises a plurality of outlet ports and
is configured to direct cool air simultaneously in two or more
different lateral directions from said secondary air duct.
7. A telecommunications shelter of claim 4 wherein at least one of
said secondary air ducts comprises a plurality of outlet ports and
is configured to direct cool air simultaneously in two or more
different lateral directions from said secondary air duct.
8. A telecommunications shelter of claim 2 wherein at least one of
said secondary air ducts comprises a plurality of outlet ports and
is configured to direct cool air simultaneously to two or more
different vertical levels.
9. A telecommunications shelter of claim 5 wherein one or more of
said secondary air duct segments includes an outlet port for
venting cool air therefrom.
10. A telecommunications shelter of claim 9 wherein said one or
more primary air ducts comprises a plurality of detachably
connected duct segments.
11. A telecommunications shelter of claim 2 comprising two or more
said vertical racks having telecommunications and electronic
components mounted at different vertical levels thereon, and
wherein one of said secondary air ducts is configured to direct air
toward two or more of said vertical racks,
12. A telecommunications shelter of claim 2 comprising two or more
of said vertical racks having telecommunications and electronic
components mounted thereon at different vertical levels, and
wherein one or more of said secondary air ducts comprises a
plurality of detachably connected duct segments whereby the length
of a said secondary air duct is adjustable for delivering cool air
at selected vertical levels and/or selected horizontal
locations.
13. A telecommunications shelter of claim 12 wherein one or more of
said secondary air duct segments includes an outlet port for
venting cool air therefrom.
14. A telecommunications shelter of claim 13 wherein said one or
more primary air ducts comprises a plurality of detachably
connected duct segments.
15. A telecommunications shelter of claim 11 wherein at least one
of said secondary air ducts comprises one or more direction and/or
air flow adjustable air vents.
16. A telecommunications shelter of claim 11 wherein at least one
of said secondary air ducts comprises a plurality of outlet ports
and is configured to direct cool air simultaneously to two or more
different vertical levels.
17. A telecommunications shelter of claim 12 wherein at least one
of said secondary air ducts comprises a plurality of outlet ports
and is configured to direct cool air simultaneously to two or more
different vertical levels.
18. A telecommunications shelter of claim 1 wherein said
refrigeration system comprises an ammonia-water absorption chiller,
and a heat transfer loop for directing chilled heat transfer fluid
between said chiller and said indoor air cooling unit.
19. A telecommunications shelter of claim 1 wherein said
refrigeration system comprises an ammonia-water GAX chiller, and a
heat transfer loop for directing heat transfer fluid between said
GAX chiller and said indoor air cooling unit.
20. A telecommunications shelter of claim 1 wherein said
refrigeration system comprises a complex compound absorption
system, and a heat transfer loop for directing heat transfer fluid
between said absorption system and said indoor air cooling
unit.
21. A telecommunications shelter of claim 1 wherein said
refrigeration system comprises a vapor compression refrigeration
unit configured for cooling a heat transfer fluid, a heat transfer
loop for directing a heat transfer fluid between said refrigeration
unit and an ice storage tank and a cold water loop to said indoor
air cooling unit.
22. A telecommunications shelter of claim 1 wherein said
refrigeration system comprises a refrigerant vapor compression
apparatus, and a heat transfer loop for directing refrigerant
between said refrigeration system and said indoor air cooling unit,
and wherein said electric power generating unit comprises a gas
fired generator.
Description
BACKGROUND OF THE INVENTION
[0001] There are thousands of telecommunications shelters located
throughout the country containing iDen, combined iDen/CDMA or other
radio or telecommunications equipment and components. Such a
telecommunications shelter is a small building, typically about 8
feet-14 feet long, about 7 feet-8 feet high and enclosing an
interior room or chamber providing weather protection and security
for the equipment. The shelter is cooled by one or two AC-powered
on-site air conditioner(s), typically wall mounted, for maintaining
the interior air temperature below that which would cause the
telecommunications system to shut down or otherwise fail or
compromise reliable operations, typically about 40.degree. C.
(104.degree. F). During a power outage in which there is loss of AC
power to the on-site air conditioner(s), temperatures within a
shelter may rise rapidly since battery back-up continues heat
generating operation of the electronics but without operating an
air conditioner, leading to an equipment shut-down, often after
only a few minutes. The use of back-up Diesel generators to operate
the air conditioners during such power outages is undesirable due
to pollution, noise and their limited reliability. The use of
outside ambient air to cool the shelter anterior is also
impractical, if ambient temperatures reach or exceed the mid or
high 90s (.degree. F). Moreover, the use of outdoor air poses a
dust contamination risk, especially at high air flows, which also
requires a significant electric power source for operating the fan,
especially if filters are partially or fully clogged with dust or
debris.
SUMMARY OF THE DISCLOSURE
[0002] The telecommunications shelter described herein is
characterized by a back-up cooling apparatus incorporating an
outdoor refrigeration system and an indoor air cooling unit
comprising an air handler housing a heat exchanger comprising an
evaporator which receives refrigerant or a liquid-air heat
exchanger which receives cooled heat transfer fluid from the
outdoor refrigeration system. The back-up cooling apparatus also
includes an air distribution assembly cooperating with the air
cooling unit and comprising one or more primary air ducts for
directing cool air from the evaporator and a plurality of secondary
air ducts communicating with the primary air ducts. Each of the
secondary air ducts are capable of delivering cold air to one or
more selected vertical racks at one or more vertical levels within
the interior chamber. In a preferred embodiment, the secondary air
ducts include one or more air vents or outlet ports configured to
selectively direct and/or adjust cold air flow to selected
components and heat loads. The air handler incorporates one or more
fans for returning warm air from the interior chamber to the
evaporator and forcing cool air through the primary and secondary
air ducts. The back-up cooling apparatus further comprises an
electric power generating unit configured to provide power for
operating the outdoor refrigeration system or a fuel supply, such
as propane or hydrogen, for operating a thermally activated
refrigeration system requiring only minimal power delivery from a
supplemental power generation system, e.g., a fuel cell,
micro-turbine, gas expansion power cycle, or batteries. The back-up
cooling apparatus also comprises the indoor air cooling unit, a
sensor for detecting an AC power outage and a sensor for sensing
the interior chamber air temperature, and a thermostat or
controller that initiates and controls operation of the back-up
cooling apparatus in response to a power outage or air temperature
at or above a predetermined limit. Specific details and description
of the various components of the back-up cooling apparatus, outdoor
refrigeration system, air cooling unit and air distribution
assembly are presented in the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a perspective view of a telecommunications shelter
with roof and two sidewalls removed to show the interior chamber
and indoor and outdoor components of the back-up cooling
apparatus;
[0004] FIG. 2 is a perspective view illustrating a plurality of
vertical racks and telecommunications equipment and another
configuration of indoor air distribution assembly components;
[0005] FIG. 3 is a perspective view showing a different
configuration of vertical racks for telecommunications equipment
and a different air distribution assembly embodiment;
[0006] FIG. 4 is a sectional view of connected air duct segments;
and
[0007] FIG. 5 illustrates a portion of a secondary air duct showing
connected segments and illustrating examples of a plurality of air
distribution outlet ports positioned for delivering air at
different selected vertical levels.
DETAILED DESCRIPTION
[0008] In FIG. 1, the front and side walls of the
telecommunications shelter 10 are eliminated to show the interior
chamber 11 in which there are positioned a plurality of vertical
racks 25, each having a number of shelves for supporting various
telecommunications and electronic equipment and components. An
AC-powered air conditioner 24 is mounted on an exterior wall of the
shelter and which normally supplies the cooling for the interior
chamber to keep the heat generating electronic telecommunications
components within desired operating temperature ranges. A door 26
and doorway 13 allows access to the equipment.
[0009] The back-up cooling apparatus embodiment shown includes an
outdoor cooling or refrigeration system 12 which supplies a
condensed refrigerant or chilled heat transfer fluid via
refrigerant piping 14 and pump 17 to an indoor air cooling unit 15
which comprises an evaporator and air handler. The term
"evaporator" as used herein is intended to include any conventional
or commercial refrigeration heat exchanger capable of transferring
heat from the warm chamber air to cold refrigerant or chilled heat
transfer fluid. Conventional evaporator designs include refrigerant
tubing, fins, an accumulator, and a capillary inlet tube for
refrigerant evaporation. Alternatively, the cooling unit may
comprise a cooling coil for circulating cold water or other chilled
heat transfer fluid for cooling the indoor air. The air handler
includes one or more fans, preferably variable speed, for moving
the warm air from the interior chamber to the evaporator and for
forcing cooled air from the evaporator through the air distribution
assembly. Such an air cooling unit design, configuration and
components are well known to those skilled in the art and need not
be discussed in further detail.
[0010] The air distribution assembly embodiment shown in FIG. 1
includes a single primary air duct 20, one end of which is in open
communication with the air cooling unit whereby the fan forces the
cool air into and along the primary air duct. The opposite end of
the primary air duct is closed. Communicating with and extending
from primary air duct 20 are a plurality of secondary air ducts 30.
The secondary air ducts shown include a horizontal section 31 which
communicates with and extends from the primary air duct, and a
vertical section 33 extending downwardly from the horizontal
portion 31. The diameter of a secondary air duct is smaller than
that of the primary air duct. The secondary air ducts preferably
are configured with one or more vents which may be adjusted or
adapted for directing cold air to selected components and heat
loads as needed. The primary air duct is positioned and extends
generally horizontally from the air cooling unit 15 at a level
above the top of the vertical racks. The primary air duct 20 can be
secured by any convenient means such as hangers extending from the
interior ceiling of the housing. Other supports or components for
securing and maintaining the position of the primary air duct may
be used.
[0011] The FIG. 1 embodiment also shows a propane or natural gas
fired generator 18 capable of providing power for operating the
outdoor refrigeration system and the indoor air cooling unit.
Alternatively, photovoltaic (PV) solar panels may be used as may
regular back-up batteries, where desired or feasible.
[0012] FIG. 2 shows another view of the air distribution assembly
similar to that of FIG. 1 but incorporating a single primary air
duct 20 and a plurality of secondary air ducts 30 using horizontal
sections 31 and vertical sections 33 for directing air to various
different vertical levels along the vertical racks 25. In the FIG.
2 embodiment, the vertical secondary air duct components are of
different lengths that provide air flow at different vertical
levels. Also shown is a return air duct 16 in the air cooling
unit.
[0013] In FIG. 3, the use of segmented air ducts is illustrated. In
a preferred embodiment, the lengths of primary and/or--secondary
air ducts may be modified, conveniently accomplished by using a
plurality of connected and disengagable duct segments. As shown,
primary air duct 32 includes a plurality of segments 34, 35, 36 and
38, and is branched to form two horizontal extensions positioned
above the top of the vertical racks 25. The secondary air ducts
extend vertically downwardly from the primary air duct branches.
The secondary air ducts 40 are also segmented; segments 41, 43 and
45 are shown. Any number of segments of the same or different
lengths may be used to accomplish the purpose of distributing the
air at different vertical levels thereby providing cooling to the
equipment along the vertical racks as needed.
[0014] The rack layouts and positions shown in FIGS. 1-3 are by way
of example only. Racks may be set up and changed into any
configuration including uniform alignment in rows, or staggered, or
otherwise randomly positioned, as desired.
[0015] Observing also FIG. 5, different outlet ports or vents 51,
53 and 57 are located at different vertical positions as well as
multiple horizontal positions. Thus, a secondary air duct segment
may be provided with one or more air vents at selected or needed
positions. Segment 54 is provided with two air vents, 51 and 53,
whereby air can be directed simultaneously to two vertical racks.
Segment 56 is provided with a single air vent, while segment 52 has
no air vents and is used simply for extending the length of the
secondary air duct 50. The air vents are preferably configured to
provide for adjusting the direction and/or the amount of cold air
to selected heat loads and equipment components.
[0016] FIG. 4 shows a convenient air duct configuration for
connecting and disconnecting air duct segments. As illustrated, one
end 44 of air duct segment 41 is of a smaller diameter than the
rest of the length of the air duct and is conveniently inserted
into the larger end 42 of adjacent air duct 43. The different
diameters of the ends of the segments may provide for force-fit
connection, or the ends may be threaded for detachably securing the
air duct segments. Such a feature allows the user to configure the
air duct assembly to distribute air as is needed to different
telecommunications shelters having different numbers, sizes and
positions of the vertical racks and for designing and tailoring the
air distribution to meet any desired needs for one shelter and
further modifying the air distribution where different equipment,
rack configurations and layouts dictate. Other means for detachably
securing the ends of the segments such as using clamps, screws,
clips, brackets, etc. may be used as well. The ducting itself may
be of any suitable material such as sheet metal, plastic or the
like of the type commonly used for air handling and air
conditioning ducts. The cross-sectional shape of the tubular ducts,
whether circular (cylindrical), rectangular or other shape, is not
critical. The use of cylindrical air ducts offers the advantage of
making even minor adjustments in air flow direction by simply
rotating a duct segment with an air vent as desired.
[0017] Selection of the type of outdoor refrigeration system units
may depend on costs, availability as well as technical and/or level
of refrigeration needed. Examples of different outdoor
refrigeration systems include ammonia-water absorption chillers,
complex compound refrigeration systems, vapor compression
refrigeration, alone or integrated with ice storage. Ammonia-water
absorption systems, and particular high efficiency GAX systems,
have been developed to minimize electric demands. These systems use
ammonia-water as the absorption fluid to provide chilled water (or
other heat exchange fluid) which is pumped to the indoor air
cooling unit. Alternative configurations use refrigerant
phase-change coupling. The in-shelter air cooling unit is designed
to communicate with the water or refrigerant loop from the outdoor
absorption system with the flows and temperatures selected as
needed for optimal control and to address the shelter-specific
conditions desired. Such ammonia-water, and particularly the high
efficiency GAX systems, are described in U.S. Pat. Nos. Re. 36,684
and 6,631,624, the descriptions of which are incorporated herein by
reference in their entireties, respectively. Other useful
ammonia-water absorption chillers are described in U.S. Pat. Nos.
5,271,235, 5,579,652, and 5,490,393.
[0018] Another useful outdoor refrigeration system requiring low
electric power incorporates complex compound technology based on
solid-gas absorption of a polar gas refrigerant on metal inorganic
sorbents. The preferred cycle uses ammonia refrigerant and all
materials are biodegradable with no global warming or ozone
depletion potential. Such a system incorporates two or more
stationary sorbers that alternately absorb and desorb the
refrigerant, a condenser for the refrigerant, an evaporator for
cooling water or other heat transfer fluid and a heat transfer
fluid loop between the outdoor system and the indoor air cooling
unit. The system can be propane or natural gas fired with possible
conversion to hydrogen fuel, when commercially available and
viable. The advantage of such a system is that there are no moving
parts in the internal sorption cycle and the avoidance of a
solution pump further reduces electric consumption. Such a system
may be built to reject heat at relatively high ambient temperature,
thereby reducing the need for excessive air flow and associated
electric fan power. When compared to an ammonia-water system,
although the fuel efficiency is not as good, electric power
consumption is lower. Examples of such complex compound outdoor
refrigeration systems are described in U.S. Pat. Nos. 5,598,721,
6,224,842 and 6,736,194, the descriptions of which are incorporated
herein by reference in their respective entireties.
[0019] Another example of useful outdoor refrigeration system
utilizes integrated ice storage and vapor compression
refrigeration. The outdoor system comprises a unitary vapor
compression refrigeration system and a suction temperature tracking
chiller. The vapor compression refrigeration system utilizes Freon
refrigerant, e.g., RM34a or R410A. Ethylene glycol or propylene
glycol may be used as a heat transfer fluid from and to the ice
storage tank. Inside shelter air cooling is provided by chilled
water from the ice storage tank pumped to the inside air cooling
unit. Such a system has very low electric demand during power-out
periods, easily fulfilled by PV, solar panels with battery buffer,
regular back-up batteries or a small propane generator.
[0020] Yet another outdoor refrigeration system utilizes a
conventional vapor compression air conditioner system based on
commercially available R134a or R410A refrigerants and a small
propane fired generator. Such a system is illustrated in FIG. 1.
Use of variable speed compressors further reduce the overall
on-site fuel storage requirements.
* * * * *