U.S. patent application number 15/905195 was filed with the patent office on 2018-07-05 for cooling control for data centers with cold aisle containment systems.
This patent application is currently assigned to PANDUIT CORP.. The applicant listed for this patent is PANDUIT CORP.. Invention is credited to Mahmoud I. Ibrahim, Bharathkrishnan Muralidharan, Saurabh K. Shrivastava.
Application Number | 20180192548 15/905195 |
Document ID | / |
Family ID | 55438897 |
Filed Date | 2018-07-05 |
United States Patent
Application |
20180192548 |
Kind Code |
A1 |
Shrivastava; Saurabh K. ; et
al. |
July 5, 2018 |
COOLING CONTROL FOR DATA CENTERS WITH COLD AISLE CONTAINMENT
SYSTEMS
Abstract
Embodiments of the present invention generally relate to the
field of data center cooling and energy management. In some
embodiments disclosed herein, a pressure within a cold aisle
containment enclosure within a data center is controlled by a
controller through the use of active floor damper panels.
Inventors: |
Shrivastava; Saurabh K.;
(Redmond, WA) ; Ibrahim; Mahmoud I.; (Chicago,
IL) ; Muralidharan; Bharathkrishnan; (Tinley Park,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PANDUIT CORP. |
TINLEY PARK |
IL |
US |
|
|
Assignee: |
PANDUIT CORP.
TINLEY PARK
IL
|
Family ID: |
55438897 |
Appl. No.: |
15/905195 |
Filed: |
February 26, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14847711 |
Sep 8, 2015 |
9943011 |
|
|
15905195 |
|
|
|
|
62048423 |
Sep 10, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 7/20745 20130101;
H05K 7/1488 20130101; H05K 7/20836 20130101; H05K 7/20709
20130101 |
International
Class: |
H05K 7/20 20060101
H05K007/20; H05K 7/14 20060101 H05K007/14 |
Claims
1. A portion of a data center utilizing cold aisle containment,
comprising: a cold aisle containment enclosure; first and second
rows of enclosures housing IT equipment, the first and second rows
of enclosures being on opposite sides of, and sharing, the cold
aisle containment enclosure; an under-floor cold air supply plenum
to provide cold supply air to the cold aisle containment enclosure;
an active damper floor tile between the under-floor cold air supply
plenum and the cold aisle containment enclosure; a differential
pressure sensor located in the cold aisle containment enclosure to
measure a pressure within the cold aisle containment enclosure; and
a cold aisle containment (CAC) controller to: compare the pressure
measurement from the differential pressure sensor to a differential
pressure set point; and modulate the active damper floor tile based
on the comparison between the pressure measurement from the
differential pressure sensor and the differential pressure set
point to control a flow of the cold supply air from the under-floor
cold air supply plenum to the cold aisle containment enclosure.
2. The portion of the data center of claim 1, comprising: a plenum
pressure sensor located in the under-floor cold air supply plenum
to measure a pressure within the under-floor cold air supply
plenum.
3. The portion of the data center of claim 1, wherein the CAC
controller is to: compare the measured pressure in the under-floor
cold air supply plenum from the penum pressure sensor to a plenum
pressure set point; and modulate a fan speed of a cooling unit in
the data center based on the comparison between the measured
pressure in the under-floor cold air supply plenum and the plenum
pressure set point.
4. The portion of the data center of claim 1, wherein the CAC
controller is to: compare the pressure measurement from the
differential pressure sensor to the differential pressure set point
in response to determining that the measured pressure in the
under-floor cold air supply plenum matches the plenum pressure set
point.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefits of priority to U.S.
patent application Ser. No. 14/847,711, filed on Sep. 8, 2015, and
U.S. Provisional Patent Application No. 62/048,423, filed on Sep.
10, 2014, which are incorporated herein by reference in their
entireties.
BACKGROUND OF THE INVENTION
[0002] Data center cooling energy efficiency is critical to
successful operation of modern large data centers. The cooling
infrastructure can account for an average of 40% of the total data
center energy consumption. Adopting methods to raise the efficiency
of cooling in data centers can significantly affect the cost of
running them, as well as extending their life. The current trend of
deploying high heat load density cabinets in data centers
necessitates the use of air containment systems. Many of the modern
data centers use some kind of air containment systems to achieve
high cooling energy efficiency. Air containment in simple terms
provides physical separation between the supplied cool air and the
cabinet exhaust hot air. This separation of cold and hot air
results in cooling energy savings; however, in order to observe the
maximum energy savings a proper control system for cooling units is
required. Typically, the cooling units get controlled based on a
coupled control scheme, wherein both the fan speed and the chilled
water valve/compressor speed get controlled based on a single
parameter, i.e., return or supply air temperature. These type of
control schemes work well for data centers without containment
systems but they may not be the best way to control cooling in data
centers with containment systems.
[0003] In containment systems, the cooling units and the
information technology (IT) equipment are tightly connected with
each other via supply air plenum and aisle containment system,
Therefore, it becomes important to not only have cold air available
at a proper temperature but also have the cooling airflow in the
correct amount at the IT equipment inlet. Use of coupled control
schemes (i.e. supply air temperature or return air temperature) in
containment system does not necessarily guarantee the above
conditions and almost always results in either oversupply and/or
undersupply of cooling airflow. Oversupply of cooling airflow means
waste in cooling energy and cooling capacity of the data center.
Undersupply of cooling airflow results in IT equipment starving for
c airflow, which could result in unreliable operation of IT
equipment.
[0004] One common aspect in these decoupled control methods is the
use of supply air temperature sensor to control the temperature of
the air supplied by the cooling unit. Controlling the amount of air
supplied to the data center however varies significantly between
the different methods. Some of the ways used to control the amount
of air supplied to the data center included using underfloor
pressure, server or cabinet inlet temperatures, temperature
difference across a containment, and containment pressure. If a
data center includes only one containment system, some of these
methods may succeed in reaching optimum control. Also, if a data
center includes multiple containment systems that all have exactly
the same heat load and airflow demand at all times, some of these
methods may again succeed in reaching optimum control. However, a
typical data center almost always has more than one containment
system and it is rare to have the heat load and airflow demand the
same for all containment systems at all times. In these situations,
the existing control schemes fall short of optimum control for
cooling units and result in unwanted cooling airflow bypass, which
result in waste of cooling fan energy.\
SUMMARY
[0005] In an embodiment, the present invention is a data center.
The data center comprises a first datacenter POD including a first
plurality of rows of cabinets where each of the first plurality of
rows of cabinets are adjacent to and share a first cold aisle, the
first cold aisle including a first temperature and a first pressure
set point; a second datacenter POD including a second plurality of
rows of cabinets where each of the second plurality of rows of
cabinets are adjacent to and share a second cold aisle, the second
cold aisle including a second temperature set point and a second
pressure set point; a cold air supply connected to both the first
cold aisle and the second cold aisle, the cold air supply providing
a cold air flow having both a temperature and a volumetric flow
rate associated therewith; a first active damper connected to and
between the first cold aisle and the cold air supply; a second
active damper connected to and between the second cold aisle and
the cold air supply; and a controller connected to the cold air
supply, the first active damper, and the second active damper, the
controller controlling the temperature of the cold air flow, the
controller further controlling the first active damper to partition
the volumetric flow rate to approximately achieve the first
pressure set point in the first cold aisle, the controller further
controlling the second active damper to partition the volumetric
flow rate to approximately achieve the second pressure set point in
the second cold aisle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a data center with cold
aisle containment systems according to an embodiment of the present
invention;
[0007] FIG. 2 is a schematic side view of the data center of FIG.
1;
[0008] FIG. 3 is a block diagram of a cooling control system
according to an embodiment of the present invention;
[0009] FIG. 4 is a flow chart of the cooling control system of FIG.
3;
[0010] FIG. 5 is a flow chart of the cooling unit fan speed control
of FIG. 4;
[0011] FIG. 6 is a flow chart of the supply air temperature set
point control of FIG. 4; and
[0012] FIG. 7 is a block diagram of a cooling control system
according to an alternative embodiment of the present
invention.
DETAILED DESCRIPTION
[0013] One embodiment of the present invention is a cooling control
solution for data centers with multiple cold aisle containment
(CAC) PODs. A POD is defined as two rows of cabinets sharing a
common cold aisle. The present invention includes a process that
controls the amount of cooling airflow supplied by the cooling
units and controls the amount of cooling airflow going into each
CAC POD. The cooling control scheme closely matches the amount of
air supplied by the cooling units to the amount of air required by
the IT equipment while maintaining safe cabinet inlet temperatures
(within threshold limits), to ensure safe and reliable operation of
the IT equipment. The cooling control scheme also monitors and
balances the amount of cooling airflow going into each POD.
[0014] Achieving optimum cooling control (lowest energy consumption
while maintaining cabinet inlet air temperature within user defined
threshold limits) in a data center with containment system can
require independent control of cooling fan speed and cooling air
temperature. The control scheme of the present in invention
decouples the control of the cooling unit; using at least one
variable to control the amount of air provided by the cooling unit
fan to the data center, and at least one other variable to control
the temperature of the air supplied by the cooling unit.
[0015] With the use of the present invention, the data center
manager/operator can reduce the amount of supplied cooling airflow
and hence the cooling fan power consumption, while maintaining
proper thermal environment for the IT equipment. The amount of
cooling airflow saved can be used to cool additional IT equipment
heat load (reclaim lost cooling capacity) that gets commissioned in
the future and hence helps in extending the life of the data
center. The reduction in supplied cooling airflow also optimizes
the cooling capacity usage by increasing the return air temperature
to the cooling units.
[0016] FIG. 1 is an isometric view of a data center with two CAC
PODs for an embodiment of the present invention, which includes
cabinet enclosures 1a-1d that house IT equipment 2a-2d with cold
aisle containment enclosures 3a-3b deployed for two separate PODs.
The data center is cooled using two perimeter cooling units 4a-4b.
Cabinet inlet temperature sensors 5a-5b are installed at the intake
of each cabinet enclosure 1a-1d. Containment pressure sensors 6a-6b
are installed in each cold aisle containment enclosure 3a-3b. The
raised-floor plenum in the data center has underfloor pressure
sensors 7 and supply air temperature sensors 8a-8b installed. FIG.
2 provides additional details of the data center described in FIG.
1. In FIG. 2, each of the two PODs described previously have a
combination of active damper tiles 9a-9b and perforated tiles
10a-10b. The IT equipment 2a-2d are cooled by the cold supply air
11a-11b that is flooded into the underfloor plenum, which then
enters each POD through its associated active damper tiles 9a-9b
and perforated tiles 10a-10b. Cold inlet air flow 12a-12d enters
the IT equipment 2a-2d to cool the IT equipment components and
returns to the data center room air as hot exhaust air 13a-13d. The
hot return air 14a-14b is drawn by the cooling unit fans 15a-15b
through the cooling unit 4a-4b to be cooled once again and the
cycle continues.
[0017] FIG. 3 is a block diagram of an embodiment of the present
invention and its different components. The present invention
includes an active CAC controller 17 which receives information
from all the sensors deployed in the data center; cabinet inlet
temperature sensors 5a-5d, containment pressure sensors 6a-6b,
underfloor pressure sensors 7, and supply air temperature sensors
8a-8b as well as a system for receiving information from the active
damper tiles 9a-9b on their position. Active CAC controller 17
interacts with the cooling units' fans 15a-15b and cooling units'
chilled water valves 16a-16b through the cooling units 4a-4b and it
interacts with a user interface 18 which allows the user to view
all the data received by the active CAC controller 17 and input the
desired set points for the different variables. The figure also
details which specific sensor measurement inputs are used to
control the active damper tiles 9a-9b, cooling unit fans 15a-15b
and cooling units' chilled water valves 16a-16b. Input 1(i) from
both supply air temperature sensors 8a-8b and cabinet inlet
temperature sensors 5a-5d is used to control the cooling units'
chilled water valves 16a-16b opening through the output signal
1(o). Input 2(i) from the underfloor pressure sensors 7 are used to
control the cooling unit fans 15a-15b speeds through the output
signal 2(o). Input 3(i) from the containment pressure sensors 6a-6b
is used to control the active damper tiles 9a-9b openings through
the output signal 3(o).
[0018] FIG. 4 details the flow of an embodiment of the invented
process. In step S2, the deployed sensors are constantly measuring
different variables within the data center. In step S4, providing
the information collected in step S2 to the active CAC controller
17 and the user interface 18. In Step S6, the active CAC controller
17 modulates local active damper tiles 9a-9b based on local POD
containment pressure sensor reading 6a-6b and POD differential
pressure set point defined in user interface 18. In Step S8, the
active CAC controller 17 modulates cooling units' fans 15a-15b
speed based on underfloor pressure sensor reading 7 and underfloor
pressure set point defined in user interface 18. With airflow
balanced between all PODS in the data center and the underfloor
pressure set point satisfied, in step S 10 the active CAC
controller 17 modulates chilled water valve 16a-16b opening based
on supply air temperature sensor reading 8a-8b and supply air
temperature set point defined in user interface 18.
[0019] Using the above described process, airflow is matched in
each CAC POD based on the IT equipment 2a-2d airflow demand in the
respective POD to the air supplied by the cooling unit fans 15a-15b
which ensures that minimum to none of the air supplied is wasted.
This helps achieve the optimum control of the cooling unit fans
15a-15b which in turn reduces their energy consumption. In addition
to energy savings, saving the amount of air flow supplied by the
cooling unit fans 15a-15b also optimizes the cooling capacity usage
of the cooling units 4a-4b, allowing to extend the life of the data
center and enabling the use of the full designed capacity of the
cooling units 4a-4b.
[0020] FIG. 5 details the flow chart for cooling unit fans 15a-15b
speed control. In step S12, containment pressure sensor 6a-6b
measurements, and underfloor pressure sensor 7 measurements are
reported to the active CAC controller 17. In Step 14, the active
CAC controller 17 checks if any of the pressure sensors are not
working. If a pressure sensor isn't working, an alarm is sent to
the user interface 18 to report which sensor is not working in step
S16. In step S18, the active CAC controller 17 checks if the
underfloor pressure sensor 7 measurements match the underfloor
pressure set point defined in user interface 18. If not, in step
S20 a proportional integral control loop is used to control the
cooling units' fans 15a-15b to maintain the underfloor pressure set
point. If the underfloor pressure set point is satisfied in step
S22, the active CAC controller 17 checks if all containment
pressure sensor 6a-6b measurements match the containment pressure
set point defined in user interface 18 in step S24. If the
containment pressure sensor 6a-6b measurements do not match the set
point in step S24, the active CAC controller 17 checks if the
active damper tiles 9a-9b associated with the cold aisle
containment enclosure 3a-3b that has a mismatch in pressure is at a
100% or 0% opening in step S26; if so, in step S28, active CAC
controller 17 overrides the initial underfloor pressure set-point
condition and controls the cooling units' fans' 15a-15b speed based
on the containment pressure sensor 6a-6b to maintain its set
point.
[0021] FIG. 6 details the flow chart for the supply air temperature
set point control. In step S42, all supply temperature sensors'
8a-8b measurements, and cabinet inlet temperature sensor 5a-5d
measurements are reported to the active CAC controller 17. In step
S44, the active CAC controller 17 checks if any of the temperature
sensors are not working. If a temperature sensor isn't working, an
alarm is sent to the user interface 18 in step S45 to report which
sensor is not working. In S46 the active CAC controller 17 checks
if a POD door is open. If so, an alarm is sent to the user
interface 18 in step S47 to report which POD door is open and
active controller 17 does not make any changes. If no POD door is
open, the active CAC controller 17 checks if the supply air
temperature sensor 7 measurement is within range of the supply air
temperature set point in step S48. if not within range, the active
CAC controller 17 does not make any changes, to wait for the
cooling units chilled water valve 16a-16b to regulate based on the
supply air temperature set point. If within range, in step S50 the
active CAC controller 17 checks if all cabinet inlet temperature
sensor 5a-5d measurements are within range of the cabinet inlet
temperature set point. If yes, the active CAC controller 17 does
not make any changes. If no, in step S51 active CAC controller 17
changes the supply air temperature set point defined in the user
interface 18 by a delta value defined in the user interface 18.
[0022] In another embodiment, according to the present invention,
the cooling units 4a-4b illustrated in FIG. 1 and FIG. 2 can be
replaced with large air handling units that are physically located
outside of the data center. However, cold air supply to the data
center and warm air exhaust from the data center are in a similar
fashion as depicted in FIG. 1 and FIG. 2.
[0023] In another embodiment, according to the present invention,
the cooling units 4a-4b illustrated in FIG. 1 and FIG. 2 can be
direct expansion (DX) cooling units that utilize a compressor for
cooling instead of the chilled water supply. In this case, the
cooling capacity is regulated by a compressor speed instead of a
chilled water valve opening.
[0024] In another embodiment, according to the present invention,
the cooling units 4a-4b illustrated in FIG. 1 and FIG. 2 can be
equipped with air-side economization and/or evaporative cooling
capability. In this case, the cooling capacity is regulated using
supply air set point temperature and outside ambient air
condition.
[0025] In another embodiment, according to the present invention,
the active damper tiles 9a-9b are controlled through a damper tile
controller 19 instead of the active CAC controller 17, based on a
user specified set point through the user interface 18. All other
aspects of the present invention remain the same. FIG. 7 is a block
diagram of the present invention in the separate described
embodiment.
[0026] Note that while this invention has been described in terms
of several embodiments, these embodiments are non-limiting
(regardless of whether they have been labeled as exemplary or not),
and there are alterations, permutations, and equivalents, which
fall within the scope of this invention. Additionally, the
described embodiments should not be interpreted as mutually
exclusive, and should instead be understood as potentially
combinable if such combinations are permissive. It should also be
noted that there are many alternative ways of implementing the
methods and apparatuses of the present invention. It is therefore
intended that claims that may follow be interpreted as including
all such alterations, permutations, and equivalents as fall within
the true spirit and scope of the present invention.
* * * * *