U.S. patent application number 12/463173 was filed with the patent office on 2009-11-12 for air flow controller for electrical equipment holder.
This patent application is currently assigned to Degree Controls, Inc.. Invention is credited to Rajesh M. Nair.
Application Number | 20090277622 12/463173 |
Document ID | / |
Family ID | 41265929 |
Filed Date | 2009-11-12 |
United States Patent
Application |
20090277622 |
Kind Code |
A1 |
Nair; Rajesh M. |
November 12, 2009 |
AIR FLOW CONTROLLER FOR ELECTRICAL EQUIPMENT HOLDER
Abstract
A fan is controlled to remove or provide air from or to an
equipment enclosure as a function of a difference in pressure
between a front and back of a rack of equipment.
Inventors: |
Nair; Rajesh M.; (Nashua,
NH) |
Correspondence
Address: |
SCHWEGMAN, LUNDBERG & WOESSNER, P.A.
P.O. BOX 2938
MINNEAPOLIS
MN
55402
US
|
Assignee: |
Degree Controls, Inc.
Milford
NH
|
Family ID: |
41265929 |
Appl. No.: |
12/463173 |
Filed: |
May 8, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61051952 |
May 9, 2008 |
|
|
|
Current U.S.
Class: |
165/246 ;
165/121; 165/244 |
Current CPC
Class: |
F24F 2110/30 20180101;
H05K 7/20836 20130101; F24F 11/0001 20130101; F24F 11/75
20180101 |
Class at
Publication: |
165/246 ;
165/244; 165/121 |
International
Class: |
F24F 11/04 20060101
F24F011/04 |
Claims
1. A method comprising: measuring a difference in air pressure
between a first side of an equipment enclosure and a second side of
the equipment enclosure, wherein some equipment mounted in the
enclosure has self contained cooling mechanisms that cool based on
convection; and controlling the measured differential air pressure
about a desired set point.
2. The method of claim 1 wherein the set point is zero.
3. The method of claim 1 wherein the difference in air pressure is
measured by a differential pressure sensor having two tubes, a
first tube having an opening positioned near the first side of the
equipment enclosure and a second tube having an opening positioned
near the second side of the equipment enclosure.
4. The method of claim 3 wherein at least one of the tubes
comprises multiple tubes with opening positioned at different
places to provide an average of the pressure at the first or second
side of the enclosure.
5. The method of claim 1 wherein the differential air pressure is
controlled by using a fan to remove air from the second side of the
equipment enclosure.
6. The method of claim 1 wherein the differential air pressure is
controlled by using multiple fans to remove air from the second
side of the equipment enclosure.
7. The method of claim 6 wherein multiple fans are controlled as a
function of measured difference in pressure between the first side
of the enclosure and a corresponding point proximate each fan.
8. The method of claim 1 wherein the difference in air pressure is
measured as a function of air pressure at multiple points in the
first and second sides of the equipment enclosure.
9. The method of claim 1 wherein multiple wireless absolute
pressure sensors are used to sense the difference in pressure.
10. The method of claim 1 wherein the first side of the equipment
enclosure corresponds to front side of the equipment enclosure and
the second side of the equipment enclosure corresponds to a back
side of the equipment enclosure.
11. The method of claim 1 wherein the equipment enclosure comprises
a two rows of racks of equipment having an enclosed aisle between
the two rows of racks, and wherein the differential air pressure is
controlled by using a fan to provide air to the enclosed aisle.
12. A device comprising: a differential pressure sensor operable to
sense a first pressure at a first side of an equipment rack in an
enclosure and a second pressure at a second side of the equipment
rack and provide a signal representing a difference between the
first and second pressures; a fan operable to add or remove air
from the equipment enclosure; and a controller coupled to the fan
for receiving the signal from the differential pressure sensor and
controlling the fan about a differential pressure set point.
13. The device of claim 12 wherein the first side of the equipment
rack corresponds to a front side of the equipment enclosure.
14. A system comprising: an equipment enclosure; multiple pieces of
equipment, each having a fan for cooling itself; a differential
pressure sensor operable to sense a first pressure at a first side
of an equipment enclosure and a second pressure at a second side of
the equipment enclosure and provide a signal representing a
difference between the first and second pressure; a fan supported
by the equipment enclosure and operable to remove air from the
second side of the equipment enclosure; and a controller coupled to
the fan for receiving the signal from the differential pressure
sensor and controlling the fan about a differential pressure set
point.
15. The system of claim 14 wherein the first side of the equipment
enclosure corresponds to front side of the equipment enclosure and
the second side of the equipment enclosure corresponds to a back
side of the equipment enclosure.
16. The system of claim 15 wherein the pieces of equipment are
supported within the enclosure such that air moves through them
generally from the front of the enclosure to the back of the
enclosure.
17. The system of claim 14 wherein the differential pressure set
point is zero.
18. A system comprising: a differential pressure sensor operable to
sense a first pressure within an enclosed aisle separating two rows
of racks of equipment and a second pressure at a side of one of the
rows of racks opposite the enclosed aisle and provide a signal
representing a difference between the first and second pressures; a
fan operable to provide air to the enclosed aisle or remove air
from the enclosed aisle separating the rows of racks of equipment;
and a controller coupled to the fan for receiving the signal from
the differential pressure sensor and controlling the fan about a
differential pressure set point.
19. The system of claim 18 wherein the fan comprises a fan assisted
floor tile.
20. The system of claim 18 wherein at least one of the equipment
has a fan to cool itself.
Description
RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 61/051,952, filed May 9, 2008, and entitled
"AIR FLOW CONTROLLER FOR ELECTRICAL EQUIPMENT HOLDER," which is
incorporated herein by reference in its entirety.
BACKGROUND
[0002] Many computer components and electrical devices are designed
with cooling mechanisms, such as fans. Airflow capacity of the fans
may be designed to cool the component or device in an open
environment. However, many times such components and devices may be
stacked or otherwise arranged in equipment holders, such as racks
with front and back panels. Placing the equipment or components in
such holders may create an environment where the fans in the
individual components and devices do not provide adequate
ventilation.
[0003] In some prior devices, temperature within the enclosure is
measured, and used to control a fan that evacuates air from the
enclosure to maintain a desired temperature range within the
enclosure. Airflow may also be measured and controlled in further
prior devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a block diagram of a system for controlling
airflow as a function of differential pressure in an equipment
enclosure according to an example embodiment.
[0005] FIG. 2 is a block schematic diagram of an alternative system
for controlling airflow according to an example embodiment.
[0006] FIG. 3 is a block schematic diagram of an alternative system
for controlling airflow according to an example embodiment.
[0007] FIG. 4 is a block schematic diagram of an alternative system
for controlling airflow according to an example embodiment.
[0008] FIG. 5 is a block schematic diagram of computer system
operable as a controller according to an example embodiment.
[0009] FIG. 6 is a block schematic diagram of an alternative system
for controlling airflow according to an example embodiment.
[0010] FIG. 7 is a block schematic diagram of a further alternative
system for controlling airflow according to an example
embodiment.
DETAILED DESCRIPTION
[0011] In the following description, reference is made to the
accompanying drawings that form a part hereof, and in which is
shown by way of illustration specific embodiments which may be
practiced. These embodiments are described in sufficient detail to
enable those skilled in the art to practice the invention, and it
is to be understood that other embodiments may be utilized and that
structural, logical and electrical changes may be made without
departing from the scope of the present invention. The following
description of example embodiments is, therefore, not to be taken
in a limited sense, and the scope of the present invention is
defined by the appended claims.
[0012] The functions or algorithms described herein may be
implemented in software or a combination of software and human
implemented procedures in one embodiment. The software may consist
of computer executable instructions stored on computer readable
media such as memory or other type of storage devices. Further,
such functions correspond to modules, which are software, hardware,
firmware or any combination thereof. Multiple functions may be
performed in one or more modules as desired, and the embodiments
described are merely examples. The software may be executed on a
digital signal processor, ASIC, microprocessor, or other type of
processor operating on a computer system, such as a personal
computer, server or other computer system.
[0013] Multiple embodiments of a system and method for controlling
a fan in an equipment enclosure as a function of differential
pressure between two sides of the equipment enclosures are
described. In some embodiments, air is removed from a back of the
enclosure to equalize the pressure. Multiple pressure measurements
may be used, and multiple fans may be controlled in various
embodiments.
[0014] In FIG. 1, a system 100 includes an equipment enclosure 110.
Equipment enclosure 110 may have supports 115 for supporting one
more pieces of equipment 120. The supported equipment may be
referred to as a rack of equipment. One or more of such pieces of
equipment may have a fan for cooling itself. A differential
pressure sensor 125 is supported by the enclosure 110, and is
operable to sense a first pressure at a first side 130 of the rack
in equipment enclosure 110 and a second pressure at a second side
135 of the rack in equipment enclosure 110. The differential
pressure sensor may provide a signal representing a difference
between the first and second pressure. In one embodiment, wireless
absolute pressure sensors 140, 141 are used to sense the first and
second pressures.
[0015] A fan 145 is supported by the equipment enclosure 110 and is
operable to remove air from the second side 135 of the equipment
enclosure 110. A controller 150 is coupled to the fan 145 and
receives the signal from the differential pressure sensor 125 or
sensors 140, 141, or both. Controller 150 controls the fan about a
differential pressure set point, such as zero in one embodiment to
provide an environment for the equipment 120 that is similar to
that for which it is designed, such as where equipment 120 is free
standing and not supported within an equipment enclosure.
[0016] In one embodiment, controller 150 may be a PID controller,
controlling the fan to keep the differential pressure about a
predetermined or pre selected set point, such as zero in one
embodiment. Other set points may be used, to create a decrease in
pressure if desired to allow cooling mechanisms in the equipment to
operate at reduced levels or just provide more effective cooling. A
range of set points may also be utilized to control the difference
in pressure, such as plus or minus 0.1 atmospheres about a set
point which may be zero in one embodiment.
[0017] In one embodiment, the first side 130 of the equipment
enclosure 110 corresponds to front side of the equipment enclosure
110 and the second side 135 of the equipment enclosure corresponds
to a back side of the equipment enclosure 110. In some embodiments,
the front side is an air intake side, and the back side is and air
exhaust side.
[0018] The pieces of equipment 120 may be supported within the
enclosure such that air moves through them generally from the front
of the enclosure to the back of the enclosure. In further
embodiments, different pieces of equipment 120 may be mounted such
that their airflow direction alternates at adjacent pieces of
equipment 120, or may be mounted without regard to their airflow
direction. In still further embodiments, only one side of the
equipment rack may be enclosed. The pressure difference may then be
measured between the side of the equipment rack that is enclosed,
and the side that is not. Air may be exhausted or provided to the
enclosure in some embodiments.
[0019] FIG. 2 is a block schematic diagram illustrating an
alternative pressure sensing arrangement. The numbering is
consistent with FIG. 1. In one embodiment, pressure sensor 125 is a
capacitive differential pressure sensor, with a first pressure from
a tube 210 having an opening 215 providing a pressure from the
first side 130 of enclosure 110. A second pressure is provided by a
second tube 220 having an opening 225 proximate the second side 135
of enclosure 110. The tubes may be supported many different ways
within the enclosure, or even on the outside of the enclosure if
desired. The openings 215 and 225 may be placed to conduct the
pressures corresponding closest to the pressures encountered by the
equipment 120 to either side of a capacitive diaphragm within the
pressure sensor 125. In some embodiments, the openings are not
placed in areas of high air velocity, as such a placement could
affect the pressure encountered. In further embodiments, any type
of differential pressure sensor may be used.
[0020] FIG. 3 is a block schematic diagram illustrating a further
embodiment 300 where the pressure sensor 125 is provided an average
pressure from multiple openings 310, 315, 320 about the first side
130 of the enclosure 110, and from multiple openings 325, 330, 335
about the second side 125 of the enclosure 110. In this embodiment,
such pressure readings are somewhat averaged by the connection of
multiple tubes to the differential pressure sensor 125. The tubes
are shown as connecting at some distance from the differential
pressure sensor 125, which may not result in a true average of the
pressure. In further embodiments, completely separate tubes joining
at the differential pressure sensor 125 may be used to obtain an
even closer average of the pressures.
[0021] FIG. 4 is a block schematic diagram illustrating a further
embodiment 400, where multiple fans 410, 415, 420 are used with
independent pressure measurements. A combined differential pressure
sensor and controller 425, 430 and 435 are used to control each
corresponding fan. Differential pressure sensor and controller 425
has tubes 440 and 442 positioned to provide differential pressure
from the first side 130 and second side 135 proximate one piece of
equipment 444. Fan 410 is then controlled by controller 425 based
on differential pressure between first and second side of equipment
444. Fan 410 is positioned adjacent equipment 444 in order to more
directly lower pressure at the second side of equipment 444, and
have less effect regarding other equipment in the enclosure.
[0022] Similarly, differential pressure sensor and controller 430
has tubes 450 and 452 positioned to provide differential pressure
from the first side 130 and second side 135 proximate one piece of
equipment 454. Fan 415 is then controlled by controller 430 based
on differential pressure between first and second side of equipment
454. Fan 415 is positioned adjacent equipment 454 in order to more
directly lower pressure at the second side of equipment 454, and
have less effect regarding other equipment in the enclosure.
[0023] Similarly, differential pressure sensor and controller 435
has tubes 460 and 462 positioned to provide differential pressure
from the first side 130 and second side 135 proximate one piece of
equipment 464. Fan 420 is then controlled by controller 435 based
on differential pressure between first and second side of equipment
464. Fan 420 is positioned adjacent equipment 464 in order to more
directly lower pressure at the second side of equipment 464, and
have less effect regarding other equipment in the enclosure.
Further fans and controllers may be provided for additional
equipment. In further embodiments, two fans and controllers may be
used for multiple pieces of equipment without a one to one
correspondence. The multiple fans may be controlled as a function
of one or more differential pressure measurements.
[0024] In various embodiments, the controller may be a general
programmed computing device as shown in FIG. 5 or a dedicated
controller implementing one or more forms of PID control or other
control as desired to operate the fans to a desired set point. In
one embodiment, a computer 510, may include a processing unit 502,
memory 504, removable storage 512, and non-removable storage 514.
Memory 504 may include volatile memory 506 and non-volatile memory
508. Computer 510 may include--or have access to a computing
environment that includes--a variety of computer-readable media,
such as volatile memory 506 and non-volatile memory 508, removable
storage 512 and non-removable storage 514. Computer storage
includes random access memory (RAM), read only memory (ROM),
erasable programmable read-only memory (EPROM) & electrically
erasable programmable read-only memory (EEPROM), flash memory or
other memory technologies, compact disc read-only memory (CD ROM),
Digital Versatile Disks (DVD) or other optical disk storage,
magnetic cassettes, magnetic tape, magnetic disk storage or other
magnetic storage devices, or any other physical medium capable of
storing computer-readable instructions. Computer 510 may include or
have access to a computing environment that includes input 516,
output 518, and a communication connection 520. The computer may
operate in a networked environment using a communication connection
to connect to one or more remote computers. The remote computer may
include a personal computer (PC), server, router, network PC, a
peer device or other common network node, or the like. The
communication connection may include a Local Area Network (LAN), a
Wide Area Network (WAN) or other networks.
[0025] Computer-readable instructions stored on a computer-readable
medium are executable by the processing unit 502 of the computer
510. A hard drive, CD-ROM, and RAM are some examples of articles
including a computer-readable medium. For a controller application,
many of the above components may not be needed, and the controller
may be implemented without storage devices and various other
components not needed to control a fan.
[0026] A block schematic diagram of a further embodiment is shown
in FIG. 6 generally at 600. Electrical equivalent of airflow and
pressure in a frame is shown where equipment pressure difference is
controlled to a zero point at 610. An internal fan 620, referred to
as Fan_Eqpt is the internal fan for a piece of equipment that is
designed to offer adequate airflow at zero pressure difference. A
frame fan 630 is disposed in a frame 640 and referred to as the
Fan_Frame. This fan is varied to keep .DELTA.P=0. The pressure drop
due to series resistance from front door or rear structure is
eliminated by fan 640.
[0027] In still a further embodiment as illustrated in block cross
section form in FIG. 7, equipment may be supported within one or
more rows of racks. Two such rows of racks 710, 715 are shown in
FIG. 7 supported by a raised floor 720. A closed aisle 725 is
formed between the racks 710 and 715 by including a top 730 and
sides, one of which is visible at 735.
[0028] A fan assisted floor tile 740 contains multiple fans that
provide cooling air to the rows of racks from the floor. Without
the fans, airflow through the equipment in the racks may be
severely reduced due to a high effective flow impedance of the
racks. In one embodiment, the fan assisted floor tile is located in
the raised floor 720 and disposed directly between the rows of
racks 710, 715 to provide airflow through a grate in the floor.
[0029] A differential pressure sensor 745 is disposed to sense a
difference in pressure between the rows of racks in the aisle 715
and ambient, where equipment may exhaust air. The pressure sensor
745 is coupled to a controller 750, which in turn is coupled to
control the fan assisted floor tile 740 to provide a desired
difference in pressure as described above. Thus, the difference in
pressure from one side of a rack and another side of the rack is
sensed and used to control fans providing cooling airflow to the
enclosure. In this case, a first side of the rack corresponds to
the aisle, or an equipment enclosure, while a second side of the
rack is outside the enclosure. In still further embodiments, only
one rack is provided, with the second rack replaced with a wall to
provide enclosure of the aisle.
[0030] In the embodiment described above, closed aisle 725 is a
cold aisle. In further embodiments, closed aisle 725 may be a hot
aisle, with the fan assisted floor tile 740 disposed on the top 735
of the aisle, and pulling hot air form the aisle out of the aisle.
No raised floor is needed in this embodiment, and cool air from
outside the racks may be drawn in through the racks to cool them.
The pressure sensing and fan control may be controlled in a similar
manner as a function of the difference in pressure.
[0031] The Abstract is provided to comply with 37 C.F.R.
.sctn.1.72(b) to allow the reader to quickly ascertain the nature
and gist of the technical disclosure. The Abstract is submitted
with the understanding that it will not be used to interpret or
limit the scope or meaning of the claims.
* * * * *