U.S. patent application number 17/114972 was filed with the patent office on 2021-03-25 for cooling system for high density heat loads.
The applicant listed for this patent is Vertiv Corporation. Invention is credited to Thomas HARVEY, Stephen SILLATO.
Application Number | 20210092880 17/114972 |
Document ID | / |
Family ID | 1000005255201 |
Filed Date | 2021-03-25 |
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United States Patent
Application |
20210092880 |
Kind Code |
A1 |
HARVEY; Thomas ; et
al. |
March 25, 2021 |
Cooling System For High Density Heat Loads
Abstract
A pumped refrigerant cooling system having multiple pumping
units for providing working fluid to a load to enable cooling of a
space via the load. The pumped refrigerant cooling system operates
the pumping units at less than capacity. When a pumping unit is
deactivated, the output of the remaining pumping units is increased
to maintain fluid flow.
Inventors: |
HARVEY; Thomas; (Columbus,
OH) ; SILLATO; Stephen; (Westerville, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vertiv Corporation |
Columbus |
OH |
US |
|
|
Family ID: |
1000005255201 |
Appl. No.: |
17/114972 |
Filed: |
December 8, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16405502 |
May 7, 2019 |
10897838 |
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17114972 |
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15498586 |
Apr 27, 2017 |
10292314 |
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16405502 |
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|
13723661 |
Dec 21, 2012 |
9706685 |
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15498586 |
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61580686 |
Dec 28, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 7/20318 20130101;
H05K 7/20709 20130101; H05K 7/20327 20130101; H05K 7/20836
20130101; H05K 7/20827 20130101 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1. A method for providing redundant cooling in a cooling system
comprising: providing a plurality of cooling modules, the plurality
of cooling modules cooperating to pump cooling fluid to at least
one thermal load, wherein the cooling modules operating at variable
speeds; increasing a speed of one of the plurality of cooling
modules when another of the plurality of cooling modules
experiences a decrease in speed; and decreasing the speed of the
one of the plurality of cooling modules when another of the
plurality of cooling modules experiences an increase in speed.
2. The method of claim 1 further comprising monitoring the
plurality of cooling modules to detect a fault condition, and
increasing the speed of the one of the plurality of cooling modules
with the other of the plurality of cooling modules indicates the
fault condition.
3. The method of claim 2 further comprising continuing to monitor
the other of the plurality of cooling modules following indication
of the fault condition to determine when the other of the plurality
of cooling modules is no longer indicating the fault condition.
4. The method of claim 3 wherein when the other of the plurality of
cooling modules no longer indicates the fault condition, the
plurality of cooling modules return to operating at respective
normal speeds.
5. A method for providing redundant cooling in a cooling system
comprising: providing a first cooling module, the first cooling
module providing cooling fluid to thermal load, wherein the first
cooling module operates at variable speeds, the first cooling
module having a first normal operating speed, the first normal
operating speed being less than a full speed; providing a second
cooling module, the second cooling module providing cooling fluid
to the thermal load, wherein the second cooling module operates at
variable speeds, the second cooling module having a second normal
operating speed, the second normal operating speed being less than
full speed; increasing a speed of one of the first cooling module
or second cooling module when the other of the first cooling module
or second cooling module is operating at less than its respective
normal operating speed; and decreasing the speed of the one of
first cooling module or second cooling module when the other of the
first cooling module or second cooling module experiences an
increase in speed.
6. The method of claim 5 further comprising monitoring the first
cooling module and the second cooling module to detect a fault
condition.
7. The method of claim 6 further comprising continuing to monitor
the first cooling module and the second cooling module after
detecting the fault condition and returning the first cooling
module and the second cooling module to the respective first normal
operating speed and second normal operating speed when the fault
condition is no longer detected.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. Divisional
application Ser. No. 16/405,502, filed on May 7, 2019, which is a
divisional of U.S. Divisional application Ser. No. 15/498,586,
filed on Apr. 27, 2017, which is a divisional of U.S. application
Ser. No. 13/723,661, filed on Dec. 21, 2012, which claims the
benefit of U.S. Provisional Application No. 61/580,686 filed on
Dec. 28, 2011. The entire disclosures of each of the above
applications are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to pumped refrigerant cooling
systems for precision cooling applications having 1+1 to N+1
primary cooling circuit redundancy.
BACKGROUND
[0003] This section provides background information related to the
present disclosure which is not necessarily prior art.
[0004] A data center is a room containing a collection of
electronic equipment, such as computer servers. Data centers and
the equipment contained therein typically have optimal
environmental operating conditions, temperature and humidity in
particular. A climate control system maintains the proper
temperature and humidity in the data center.
[0005] The climate control system includes a cooling system that
cools air and provides the cooled air to the data center. The
cooling system may include air conditioning units, such as computer
room air conditioning unit (CRAC) or computer room air handlers
(CRAH) that cools the air that is provided to the data center. The
data center may have a raised floor and the cooled air introduced
into the data center through vents in the raised floor. The raised
floor may be constructed to provide a plenum between the cold air
outlet of the CRAC (or CRACs) or CRAH (or CRAHS) and the vents in
the raised floor, or a separate plenum such as a duct may be
used.
[0006] The data center could also have a hard floor. The CRACS may,
for example, be arranged in the rows of the electronic equipment,
may be disposed with their cool air supply facing respective cold
aisles, or be disposed along walls of the data center. The
equipment racks in the data center may be arranged in a hot
aisle/cold aisle configuration with the equipment racks arranged in
rows. The cold air inlets of the racks, typically at the front of
the racks, in one row face the cold air inlets of the racks in a
row across a cold aisle, and the hot air outlets of the racks in
one row face the hot air outlets of the racks in a row across a hot
aisle.
[0007] One type of cooling system uses a pumped refrigerant cooling
unit, such as the cooling units used in the XD System available
from Liebert Corporation of Columbus, Ohio. The Liebert XD System
has two cooling loops, that may also be referred to as cooling
circuits or cycles. A primary loop uses chilled water or a
refrigerant, such as R407C and a secondary loop uses a pumped
refrigerant, such as R134a. The primary loop includes a fluid to
fluid heat exchanger to cool the pumped refrigerant circulating in
the secondary loop. The secondary loop includes one or more phase
change cooling modules having a fluid to air heat exchanger through
which the pumped refrigerant is circulated to cool air flowing
across the heat exchanger.
[0008] Basic schematics for the two cooling loops (or cycles) of
the Liebert XD System are shown and described in U.S. Ser. No.
10/904,889 for "Cooling System for High Density Heat Load," the
entire disclosure of which is incorporated herein by reference.
FIGS. 1 and 2 of this application are included herein as FIGS. 1
and 2 along with the accompanying description from this
application.
[0009] Referring to FIGS. 1 and 2, the disclosed cooling system 10
includes a first cooling cycle 12 (the primary cooling loop) in
thermal communication with a second cycle 14 (the secondary cooling
loop). The disclosed cooling system 10 also includes a control
system 90. Both the first and second cycles 12 and 14 include
independent working fluids. The working fluid in the second cycle
is any volatile fluid suitable for use as a conventional
refrigerant, including but not limited to chlorofluorocarbons
(CFCs), hydro fluorocarbons (HFCs), or hydrochloro-fluorocarbons
(HCFCs). Use of a volatile working fluid eliminates using water
located near sensitive equipment, as is sometimes done in
conventional systems for cooling computer rooms. The second cycle
14 includes a pump 20, one or more first heat exchangers
(evaporators) 30, a second heat exchanger 40, and piping to
interconnect the various components of the second cycle 14. The
second cycle 14 is not a vapor compression refrigeration system.
Instead, the second cycle 14 uses the pump 20 instead of a
compressor to circulate a volatile working fluid for removing heat
from a heat load. The pump 20 is preferably capable of pumping the
volatile working fluid throughout the second cooling cycle 14 and
is preferably controlled by the control system implemented by
controller 90.
[0010] The first heat exchanger 30 is an air-to-fluid heat
exchanger that removes heat from the heat load (not shown) to the
second working fluid as the second working fluid passes through the
second fluid path in first heat exchanger 30. For example, the
air-to-fluid heat exchanger 30 can include a plurality of tubes for
the working fluid arranged to allow warm air to pass therebetween.
It will be appreciated that a number of air-to-fluid heat
exchangers known in the art can be used with the disclosed cooling
system 10. A flow regulator 32 can be connected between the piping
22 and the inlet of the evaporator 30 to regulate the flow of
working fluid into the evaporator 30. The flow regulator 32 can be
a solenoid valve or other type of device for regulating flow in the
cooling system 10. The flow regulator 32 preferably maintains a
constant output flow independent of the inlet pressure over the
operating pressure range of the system. In the embodiment of FIGS.
1 and 2, the second cycle 14 includes a plurality of evaporators 30
and flow regulators 32 connected to the piping 22. However, the
disclosed system can have one or more than one evaporator 30 and
flow regulators 32 connected to the piping 22.
[0011] The second heat exchanger 40 is a fluid-to-fluid heat
exchanger that transfers heat from the second working fluid to the
first cycle 12. It will be appreciated that a number of
fluid-to-fluid heat exchangers known in the art can be used with
the disclosed cooling system 10. For example, the fluid-to-fluid
heat exchanger 40 can include a plurality of tubes for one fluid
positioned in a chamber or shell containing a second fluid. A
coaxial ("tube-in-tube") exchanger would also be suitable. In
certain embodiments, it is preferred to use a plate heat exchanger.
The second cycle 14 can also include a receiver 50 connected to the
outlet piping 46 of the second heat exchanger 40 by a receiver
output line 52. The receiver 50 may store and accumulate the
working fluid in the second cycle 14 to allow for changes in the
temperature and heat load.
[0012] In one embodiment, the air-to-fluid heat exchanger 30 can be
used to cool a room holding computer equipment. For example, a fan
34 can draw air from the room (heat load) through the heat
exchanger 30 where the second working fluid absorbs heat from the
air. In another embodiment, the air-to-fluid heat exchanger 30 can
be used to directly remove heat from electronic equipment (heat
load) that generates the heat by mounting the heat exchanger 30 on
or close to the equipment. For example, electronic equipment is
typically contained in an enclosure (not shown). The heat exchanger
30 can mount to the enclosure, and fans 34 can draw air from the
enclosure through the heat exchanger 30. The first heat exchanger
30 could be an alternate type of heat exchanger (e.g., a cold
plate), and may be in direct thermal contact with the heat source.
It will be appreciated by those skilled in the art that the heat
transfer rates, sizes, and other design variables of the components
of the disclosed cooling system 10 depend on the size of the
disclosed cooling system 10, the magnitude of the heat load to be
managed, and on other details of the particular implementation.
[0013] In the embodiment of the disclosed cooling system 10
depicted in FIG. 1, the first cycle 12 includes a chilled water
cycle 60 connected to the fluid-to-fluid heat exchanger 40 of the
second cycle 14. In particular, the second heat exchanger 40 has
first and second portions or fluid paths 42 and 44 in thermal
communication with one another. The second fluid path 42 for the
volatile working fluid is connected between the first heat
exchanger 30 and the pump 20. The first fluid path 44 is connected
to the chilled water cycle 60. The chilled water cycle 60 may be
similar to those known in the art. The chilled water system 60
includes a first working fluid that absorbs heat from the second
working fluid passing through the fluid-to-fluid heat exchanger 40.
The first working fluid is then chilled by techniques known in the
art for a conventional chilled water cycle. In general, the first
working fluid can be either volatile or non-volatile. For example,
in the embodiment of FIG. 1, the first working fluid can be water,
glycol, or mixtures thereof. Therefore, the embodiment of the
second cycle 14 in FIG. 1 can be constructed to include the pump
20, air-to-fluid heat exchanger 30, and fluid-to-fluid heat
exchanger 40 and can be connected to an existing chilled water
service that is available in the building housing the equipment to
be cooled, for example.
[0014] In the embodiment of the disclosed cooling system 10 in FIG.
2, the second cycle 14 is substantially the same as that described
above. However, the first cycle 12 includes a vapor compression
refrigeration system 70 connected to the first portion or fluid
path 44 of heat exchanger 40 of the second cycle 14. Instead of
using chilled water to remove the heat from the second cycle 14 as
in the embodiment of FIG. 1, the refrigeration system 70 in FIG. 2
is directly connected to or is the "other half" of the
fluid-to-fluid heat exchanger 40. The vapor compression
refrigeration system 70 can be substantially similar to those known
in the art. An exemplary vapor compression refrigeration system 70
includes a compressor 74, a condenser 76, and an expansion device
78. Piping 72 connects these components to one another and to the
first fluid path 44 of the heat exchanger 40.
[0015] The vapor compression refrigeration system 70 removes heat
from the second working fluid passing through the second heat
exchanger 40 by absorbing heat from the exchanger 40 with a first
working fluid and expelling that heat to the environment (not
shown). For example, in the embodiment of FIG. 2, the first working
fluid can be any conventional chemical refrigerant, including but
not limited to chlorofluorocarbons (CFCs), hydrofluorocarbons
(HFCs), or hydrochloro-fluorocarbons (HCFCs). The expansion device
78 can be a valve, orifice or other apparatus known to those
skilled in the art to produce a pressure drop in the working fluid
passing therethrough. The compressor 74 can be any type of
compressor known in the art to be suitable for refrigerant service
such as reciprocating compressors, scroll compressors, or the like.
In the embodiment depicted in FIG. 2, the cooling system 10 is
self-contained. For example, the vapor compression refrigeration
system 70 can be part of a single unit that also houses pump 20 and
fluid-to-fluid heat exchanger 30.
[0016] During operation of the disclosed system, pump 20 moves the
working fluid via piping 22 to the air-to-fluid heat exchanger 30.
Pumping increases the pressure of the working fluid, while its
enthalpy remains substantially the same. The pumped working fluid
then enters the air-to-fluid heat exchanger or evaporator 30 of the
second cycle 14 after passing through flow regulator 32. A fan 34
can draw air from the heat load through the heat exchanger 30. As
the warm air from the heat load (not shown) enters the air-to-fluid
heat exchanger 30, the volatile working fluid absorbs the heat. As
the fluid warms through the heat exchanger, some of the volatile
working fluid will evaporate. In a fully loaded cooling system 10,
the fluid leaving the first heat exchanger 30 will be substantially
vapor. The vapor flows from the heat exchanger 30 through the
piping 36 to the fluid-to-fluid heat exchanger 40. In the return
line or piping 36, the working fluid is substantially vapor, and
the pressure of the fluid drops while its enthalpy remains
substantially constant. At the fluid-to-fluid heat exchanger 40,
the vapor in the second fluid path 42 is condensed by transferring
heat to the first, colder fluid of the first cycle 12 in the first
fluid path 44. The condensed working fluid leaves the heat
exchanger 40 via piping 46 and enters the pump 20, where the second
cycle 14 can be repeated.
[0017] The first cooling cycle 12 operates in conjunction with
second cycle 14 to remove heat from the second cycle 14 by
absorbing the heat from the second working fluid into the first
working fluid and rejecting the heat to the environment (not
shown). As noted above, the first cycle 12 can include a chilled
water system 60 as shown in FIG. 1 or a vapor compression
refrigeration system 70 as shown in FIG. 2. During operation of
chilled water system 60 in FIG. 1, for example, a first working
fluid can flow through the first fluid path 44 of heat exchanger 40
and can be cooled in a cooling tower (not shown). During operation
of refrigeration system 70 in FIG. 2, for example, the first
working fluid passes through the first portion 44 of fluid-to-fluid
heat exchanger 40 and absorbs heat from the volatile fluid in the
second cycle 14. The working fluid evaporates in the process. The
vapor travels to the compressor 74 where the working fluid is
compressed. The compressor 74 can be a reciprocating, scroll or
other type of compressor known in the art. After compression, the
working fluid travels through a discharge line to the condenser 76,
where heat from the working fluid is dissipated to an external heat
sink, e.g., the outdoor environment. Upon leaving condenser 76,
refrigerant flows through a liquid line to expansion device 78. As
the refrigerant passes through the expansion device 78, the first
working fluid experiences a pressure drop. Upon leaving expansion
device 78, the working fluid flows through the first fluid path of
fluid-to-fluid heat exchanger 40, which acts as an evaporator for
the refrigeration system 70.
[0018] Data center providers are continually seeking increased
reliability and up time from climate control systems. Therefore,
data center providers continually desire improved redundancy in the
climate control systems to guard against unnecessary down time of
the cooled electronic equipment due to unexpected interruption in
operation of the climate control systems. One mode of redundancy is
to replicate each element of a cooling system, such as the first
cooling cycle 12 and the second cooling cycle 14. Such complete
redundancy can be prohibitively expensive and greatly complicates
the design, implementation, and control of the cooling systems. In
various configurations, redundancy may include implementation of a
cooling loop, including a second, reduced implementation of a
second cooling cycle 14 such as shown in FIGS. 1 and 2. The reduced
redundancy could include a second pump unit 20 and half of the heat
exchangers provided in the primary cooling system. Implementing
this redundant system would also require the associated plumbing
and controls. Accordingly, an approximate cost of such a system
could be in the range of 50% of the total cost of the base cooling
load.
[0019] Another approach to redundancy in order to minimize
equipment can include over-provisioning the environment by
deploying cooling modules in complicated, interweaved schemes.
Failure of one cooling loop can then be covered by other cooling
loops interwoven into the zone of the failed one cooling loop. Such
over provisioning again provides increased cost to the consumer
which includes extra pumps, cooling modules, plumbing, piping and
control systems over conventional configurations shown in FIGS. 1
and 2.
SUMMARY
[0020] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features.
[0021] A cooling system having a plurality of pumping units to
supply cooling fluid to a load. In various configurations, the
pumping units supply a portion of the cooling fluid to the load. If
a pumping unit experiences a fault condition, the output of the
other pumping unit is increased to maintain sufficient fluid flow
to the load. In other configurations, an additional pumping unit is
provided which does not normally supply fluid flow to the load.
When one of the other pumping units experiences a fault condition,
the additional pumping unit is activated to provide fluid flow to
the load. In other configurations, a plurality of pumping units
provides fluid flow to a plurality of respective loads. When one of
the pumping units experiences a fault condition, a redundant
pumping unit is inserted into the circuit to supply fluid flow to
the load associated with the fault condition pumping unit.
[0022] A cooling system includes a first cooling module, the
cooling module having a first variable speed pump circulating
refrigerant through a load. The cooling system also has a second
cooling module, the second cooling module having a second variable
speed pump circulating refrigerant through the load. The first and
second variable speed pumps operate at less than full speed. When
one of the first cooling module or the second cooling modules
cannot sufficiently circulate refrigerant through the load, the
speed of the variable speed pump of another of the first or second
cooling modules is increased to compensate for the one cooling
module.
[0023] A cooling system includes a plurality of cooling modules
supplying refrigerant to a load, a plurality of cooling modules
each has a variable speed pump for supplying the refrigerant to the
load. The variable speed pumps operate at less than full speed.
When one of the plurality of cooling modules cannot sufficiently
supply refrigerant, a speed of the variable speed pump of at least
one of another of the plurality of cooling modules having a
variable speed that is increased to compensate for the one of the
plurality of cooling modules.
[0024] A method for providing redundant cooling in a cooling system
includes providing a plurality of cooling modules. The plurality of
cooling modules cooperate to pump cooling fluid to at least one
thermal load. The cooling modules operating at variable speeds. The
speed of one of the plurality of cooling modules is increased when
another of the plurality of cooling modules experiences a decrease
in speed. The speed of the one of the plurality of cooling modules
is decreased when another of the plurality of cooling modules
experiences an increase in speed.
[0025] A method for providing redundant cooling module in a cooling
system includes providing a first cooling module. The first cooling
module provides cooling fluid to a thermal load. The first cooling
module operates at variable speeds. The first cooling module has a
first normal operating speed, the first normal operating speed
being less than a full speed. Providing a second cooling module.
The second cooling module provides cooling fluid to the thermal
load. The second cooling module operates at variable speeds, the
second cooling module having a second normal operating speed, the
second normal operating speed being less than a full speed.
Increasing the speed of one of the first cooling module or second
cooling module when the other of the first cooling module or second
cooling module is operating at a speed less than its respective
normal operating speed. Decreasing the speed of the first cooling
module or second cooling module when the other of the first cooling
module or second cooling module experiences an increase in
speed.
[0026] A cooling system including: a primary cooling module. The
primary cooling module supplying refrigerant to a load. A secondary
cooling module provides a supplemental flow of refrigerant to the
load upon detection of a deficiency of the primary cooling
module.
[0027] A cooling system including: a plurality of primary cooling
modules. The primary cooling modules supply refrigerant to a
respective one of a plurality of thermal loads. A secondary cooling
module selectively provides a supplemental flow of refrigerant
through the load associated with a primary cooling module for which
a fault has been detected.
[0028] A method for providing redundant cooling in a cooling system
includes providing a primary cooling module having a circuit. The
primary cooling module provides cooling fluid to a thermal load.
Providing a secondary cooling module, and initiating operation of
the secondary cooling module upon detection of a fault in the
primary cooling module. Inserting the secondary cooling module into
the circuit, the secondary cooling module providing cooling fluid
to the thermal load, and deactivating the primary cooling
module.
[0029] A method for providing redundant control of a cooling system
includes providing a plurality of primary cooling modules. The
primary cooling modules circulates refrigerant through a respective
thermal load. Providing a secondary cooling module. The secondary
cooling module selectively provides a supplemental flow of
refrigerant through the load associated with a selected primary
cooling module when a fault is detected in one of the primary
cooling modules.
DRAWINGS
[0030] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0031] FIG. 1 is a schematic view of a primary cooling loop
connected to a chilled water cycle;
[0032] FIG. 2 is a schematic view of a cooling system having a
primary cooling loop utilizing a vapor compression refrigeration
system;
[0033] FIG. 3 is a schematic view of a cooling system arranged
according to various embodiments;
[0034] FIG. 4 is a schematic view of a cooling system arranged
according to various embodiments;
[0035] FIG. 5 is a flow diagram depicting a process for providing
redundant cooling capacity in a system having a redundant cooling
source, such as FIGS. 3 and 4;
[0036] FIG. 6. is a schematic view of a cooling system arranged
according to another various embodiment;
[0037] FIG. 7 is a flow diagram depicting a process for providing
redundant cooling in the system of FIG. 6;
[0038] FIG. 8 is a schematic view of a cooling system arranged
according to another various embodiment; and
[0039] FIG. 9 is a flow diagram depicting a process for providing
redundant cooling in the system of FIG. 9.
[0040] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0041] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0042] Example embodiments are provided so that this disclosure
will be thorough, and will fully convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific components, devices, and methods, to provide a
thorough understanding of embodiments of the present disclosure. It
will be apparent to those skilled in the art that specific details
need not be employed, that example embodiments may be embodied in
many different forms and that neither should be construed to limit
the scope of the disclosure. In some example embodiments,
well-known processes, well-known device structures, and well-known
technologies are not described in detail.
[0043] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0044] When an element or layer is referred to as being "on,"
"engaged to," "connected to," or "coupled to" another element or
layer, it may be directly on, engaged, connected or coupled to the
other element or layer, or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on," "directly engaged to," "directly connected to," or
"directly coupled to" another element or layer, there may be no
intervening elements or layers present. Other words used to
describe the relationship between elements should be interpreted in
a like fashion (e.g., "between" versus "directly between,"
"adjacent" versus "directly adjacent," etc.). As used herein, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0045] Although the terms first, second, third, etc. may be used
herein to describe various elements, components, regions, layers
and/or sections, these elements, components, regions, layers and/or
sections should not be limited by these terms. These terms may be
only used to distinguish one element, component, region, layer or
section from another region, layer or section. Terms such as
"first," "second," and other numerical terms when used herein do
not imply a sequence or order unless clearly indicated by the
context. Thus, a first element, component, region, layer or section
discussed below could be termed a second element, component,
region, layer or section without departing from the teachings of
the example embodiments.
[0046] Spatially relative terms, such as "inner," "outer,"
"beneath," "below," "lower," "above," "upper," and the like, may be
used herein for ease of description to describe one element or
feature's relationship to another element(s) or feature(s) as
illustrated in the figures. Spatially relative terms may be
intended to encompass different orientations of the device in use
or operation in addition to the orientation depicted in the
figures. For example, if the device in the figures is turned over,
elements described as "below" or "beneath" other elements or
features would then be oriented "above" the other elements or
features. Thus, the example term "below" can encompass both an
orientation of above and below. The device may be otherwise
oriented (rotated 90 degrees or at other orientations) and the
spatially relative descriptors used herein interpreted
accordingly.
[0047] FIG. 3 depicts a schematic view of a pumped refrigerant
cooling system 100 arranged in accordance with various embodiments.
The pumped refrigerant cooling system 100 includes a pair of
pumping units 120a, 120b. Pumping units 120a, 120b provide a
working fluid pumped to a load 122. Load 122 is placed in an
environment to cool, such as a data room. In some instances, n
elements may be described collectively using the reference numeral
without the a, b, . . . , n. Further, like reference numerals will
be used to describe similar elements throughout the specification.
In various configurations, load 122 can include a plurality of
loads 122, referred to collectively as load 122.
[0048] Each pumping unit 120 includes a first pump 124 and a second
pump 126 which pump the working fluid at an elevated pressure to
respective check valves 132, 134. Pumps 124, 126 can be arranged in
a first, redundant configuration. Alternatively, pumps 124, 126 can
be arranged to cooperatively apply fluid at an output pressure and
fluid flow through respective check valves 132, 134 to output line
136. Pumps 124, 126 can be controlled to provide both redundant and
cooperative operation.
[0049] Fluid pumped through output line 136 is applied to load 122.
Load 122 may assume a number of configurations, including a
configuration similar to evaporator 30 of FIGS. 1 and 2. Load 122
is placed in an environment where it is desirable to remove heat
from the environment in which load 122 is situated by transferring
the heat to fluid pumped through output line 136. Fluid from output
line 136 enters load 122 at a first temperature and exits load 122
on line 140 at an elevated temperature. Fluid pumped through load
122 may also change phase from a liquid phase to a gaseous phase.
Line 140, generally referred to as inlet line 140, returns the
working fluid to pumping unit 120.
[0050] Fluid in inlet line 140 is input to condenser 138. Condenser
138 receives the working fluid at a first, elevated temperature and
rejects the heat in the working fluid to output fluid at a reduced
temperature. Fluid passing through condenser 138 changes phase from
a gaseous to a liquid phase. The fluid output at a reduced
temperature is output through return line 144 which is input to
receiver 142. Receiver 142 stores working fluid for use by pumping
unit 120. Receiver 142 returns working fluid to respective pumps
124, 126 via receiver output line 143. A bypass line 145 bypasses
receiver enabling fluid to pass from the outlet of condenser 138
directly to receiver output line 143, bypassing receiver 142.
Receiver output line 143 provides working fluid to pumps 124, 126
via respective pump input lines 148, 150. A controller 146 connects
to each pumping unit 120, and sends and receives sense and control
signals to and from each main pumping unit 120.
[0051] In operation, respective pumping units 120a, 120b each
provide approximately 50% of the required refrigerant flow to load
122. When a scenario occurs that either of pumping units 120a or
120b provides less than the predetermined capacity, such as 50%,
the other pumping unit 120a, 120b can be controlled by controller
146 to increase the output. The output may be increased by
increasing the output of the other pump unit 120a, 120b to maintain
sufficient fluid flow to load 122. When it is determined that the
pumping unit previously determined to be providing less than full
capacity is fully back online, the output of each pumping unit
120a, 120b can be returned to a predetermined operation, such as
50% of full load.
[0052] FIG. 4 depicts a schematic view of a pumped refrigerant
cooling system 200 arranged in accordance with various embodiments.
FIG. 4 is arranged similarly to FIG. 3 described above, but
includes more than two pumping units 120. The pumped refrigerant
cooling system 200 includes a plurality of primary pumping units
120a, 120b, . . . , 120n. Each pumping unit 120a, 120b, . . . ,
120n provides a working fluid pumped to load 122 or a plurality of
loads 122 arranged in parallel. Load 122 is placed in an
environment to be cooled, such as a data room. It should be noted
that n can be any positive integer and represents a selected number
of similarly arranged elements in the figures. For example, pumping
units 120a, 120b, . . . , 120n refer to N pumping units. The number
of pumping units can be varied depending on the particular
implementation of the pumped refrigerant cooling system 200
described herein. This numbering convention will be used to
describe other similar units. In some instances, the n pumping
units may be described collectively using the reference numeral
without the a, b, . . . , n.
[0053] Operation of the pumped refrigerant cooling systems 100, 200
of FIGS. 3 and 4 will be described. Pumped refrigerant cooling
system 200 of FIG. 4 operates similarly to the pumped refrigerant
cooling system 100 of FIG. 3. Particularly, pumped refrigerant
cooling system 200 operates similarly except that it has multiple
pumping units 120 rather than the pair of pumping units 120
described in connection with FIG. 3.
[0054] In operation, pumping units 120 operate at less than full
capacity to share a portion of the fluid flow provided to load 122.
In various configurations the distribution may be equal. In other
configurations, the distribution need not be equal. When any of the
N pumping units is disabled by controller 146, a controller 146
also increases the output of the remaining (N-1) pumping units 120
to load 122 to maintain sufficient refrigerant flow through load
122. By way of non-limiting example, if N=3, and the refrigerant
flow is divided equally among the three pumping units 120, each
pumping unit applies 33.33% of the overall refrigerant flow to load
122. If any one of the N units should be deactivated by controller
146, the remaining (N-1) units provide the remaining refrigerant
flow to load 122. In this instance, each of the remaining (N-1)
units will provide approximately 50% of the total refrigerant flow
to load 122. In another non-limiting example, if N=5, each of the
primary pumping units 120 may provide 20% of the total refrigerant
flow to load 122. If controller 146 deactivates one of the pumping
units 120, the remaining four pumping units provide 25% of the
overall refrigerant flow. While the examples described herein are
directed to each pumping unit 120 providing equal refrigerant flow,
one skilled in the art would recognize that the pumping units 120
could provide unequal flow so long as the pumping units 120
remaining online can provide sufficient refrigerant flow to load
122.
[0055] FIG. 5 depicts a block diagram for providing redundancy of
the pumping units in the pumped refrigerant cooling system of FIGS.
3 and 4. The process begins at start block 151 and proceeds to
decision block 152. Decision block 152 determines if a fault has
been detected in one of the pumping units 120. If no fault has been
detected, control proceeds back to the beginning of decision block
152 which continues to monitor whether a fault condition has been
detected in a pumping unit. If a fault condition has been detected
in a pumping unit, control proceeds to block 154 where controller
146 provides a signal to increase the speed of the (N-1) pumping
units other than the fault condition pumping unit. Once the output
of the remaining (N-1) pumping units 120 has been sufficiently
increased, control proceeds to block 156. At block 156, controller
146 adjusts the output of pumping unit 120 fault condition pumping
unit 120. Controller 146 can either decrease the requested output
of the fault condition pumping unit 120 or deactivate the fault
condition pumping unit 120. Control then proceeds to block 158
which monitors for an indication that the fault condition pumping
unit 120 has returned to normal operation. If the fault condition
pumping unit has not returned to normal operation, control proceeds
back to the beginning of decision block 158. When the fault
condition pumping unit is determined to be operating properly,
control proceeds to block 160. At block 160, controller 146
generates control signals to restore fault condition pumping unit
120 previously to its normal operation output. Control then
proceeds to block 162. At block 162, controller 146 decreases the
speed of the (N-1) pumping units 120 whose speed was previously
increased in order to compensate for the prior deactivation or
reduction of output of the fault condition pumping unit 120.
Control then proceeds to block 164 where the process is
completed.
[0056] FIG. 6. depicts a cooling system 300 arranged in accordance
with various embodiments. The cooling system 300 includes pumping
units 120a, 120b, . . . , 120n which are arranged similarly to
pumping units 120 described previously herein. Pumping units 120
provide fluid flow to a pair of cooling modules or loads 122a, 122b
shown arranged in parallel. The configuration of FIG. 6 is directed
to a system including a pumping unit operating as a standby pumping
unit that is activated when one or more of the other (N-1) pumping
units must be deactivated. The standby pumping unit 120 then
becomes activated and inserted into the circuit while the other
pumping unit is deactivated by the controller 146.
[0057] FIG. 6 is arranged similarly to the various embodiments
described above. FIG. 6 also includes inlet valves 170a, 170b, , .
. . , 170n associated with respective pumping units 120a, 120b, . .
. , 120n. FIG. 6 also includes outlet valves 172a, 172b, , 172n
associated with respective pumping units 120a, 120b, . . . , 120n.
Inlet valves 170 and outlet valves 172 cooperate to enable and
disable fluid flow to and from respective pumping units 120.
Pumping unit 120n of the N pumping units function as a standby
pumping unit and is activated to provide fluid flow replacing the
fluid flow of one or more of the other (N-1) pumping units 120 when
deactivated.
[0058] FIG. 7 depicts a block diagram of the operation of the
pumped refrigerant cooling system 300 of FIG. 6. Control begins at
start block 180 and proceeds to decision block 182. At decision
block 182 the controller 146, or other portion of the system 300,
determines whether a fault condition has been detected in a pumping
unit 120. If no fault has been detected, control proceeds back to
decision block 182. If a fault has been detected, control proceeds
to block 184. At block 184, controller 146 brings the standby
pumping unit, 120n in this example, online so that standby pumping
unit 120n can provide pressurized fluid flow. Control then proceeds
to block 186 where controller 146 places the standby pumping unit
120n into the circuit by opening inlet valve 170n and outlet valve
172n. This enables standby pumping unit 120n to provide fluid flow
to load 122. Control then proceeds to block 188 where the fault
condition pumping unit 120 is removed from the circuit. Controller
146 removes the fault condition pumping unit 120 by closing its
corresponding inlet valve 170 and outlet valve 172 in order to take
the faulty pumping unit out of the circuit. Control next proceeds
to decision block 190. At decision block 190, controller 146
determines whether the fault condition pumping unit is determined
to be operating properly. If the deactivated pumping unit is not
operating properly, control returns to decision block 190. If the
fault condition pumping unit is determined to be operating
properly. Control proceeds to block 192, and controller 146 brings
the now properly operating pumping unit 120 back online so that it
can provide fluid flow of cooling fluid to the loads 122. Once the
fault condition pumping unit is brought online, control proceeds to
block 194. At block 194, the fault condition pumping unit is placed
into the circuit by opening its respective inlet valve 170 and
outlet valve 172 to enable fluid flow to load 122. Control then
proceeds to block 196. At block 196, controller 146 removes the
standby pumping unit 120n from the circuit by closing inlet valve
170n and outlet valve 172n. Control then proceeds to block 198 in
which controller 146 deactivates standby pumping units 120. Control
then proceeds to end block 199.
[0059] FIG. 8 depicts a schematic view of a pumped refrigerant
cooling system 400 having a redundant pumping unit. As described
above, the pumped refrigerant cooling system 400 includes a
plurality of main or primary pumping units 120a, 120b, . . . ,
120n. Each primary pumping unit 120a, 120b, . . . , 120n provides a
working fluid pumped to a load 122a, 122b, . . . , 122n. Each load
122a, 122b, . . . , 122n is placed in an environment to cool the
environment, such as a data room. It should be noted that n can be
any positive integer and represents a selected number of similarly
arranged elements in the figures. For example, pumping units 120a,
120b, . . . , 120n refer to N pumping units. As also described
above, one skilled in the art would recognize that the number of
pumping units can be varied depending on the particular
implementation of the pumped refrigerant cooling system 400
described herein.
[0060] Each main pumping unit 120 includes a first pump 124 and a
second pump 126 which pump the working fluid at an elevated
pressure to respective check valves 132, 134. Pumps 124, 126 can be
arranged in a first, redundant configuration. Alternatively, pumps
124, 126 can be arranged to cooperatively apply fluid at an output
pressure and fluid flow through respective check valves 132, 134 to
output line 136. Pumps 124, 126 can be controlled to provide both
redundant and cooperative operation.
[0061] Fluid pumped through output line 136 is applied to load 122.
Load 122 may assume a number of configurations, including a
configuration similar to evaporator 30 of FIGS. 1 and 2. Load 122
is placed in an environment where it is desirable to remove heat
from the environment in which load 122 is situated by transferring
the heat to fluid pumped through output line 136. Fluid from output
line 136 enters load 122 at a first temperature and exits load 122
on line 140 at an elevated temperature. Fluid pumped through load
122 may also change phase from a liquid phase to a gaseous phase.
Line 140, generally referred to as inlet line 140, returns the
working fluid to main pumping unit 120.
[0062] Fluid in inlet line 140 is input to condenser 138. Condenser
138 receives the working fluid at a first, elevated temperature and
rejects the heat in the working fluid to output fluid at a reduced
temperature. Fluid passing through condenser 138 changes phase from
a gaseous to a liquid phase. The fluid output at a reduced
temperature is output through return line 144 which is input to
receiver 142. Receiver 142 restores working fluid for use by
pumping unit 120. Receiver 142 returns working fluid to respective
pumps 124, 126 via receiver output line 143. A bypass line 145
bypasses receiver enabling fluid to pass from the outlet of
condenser 138 directly to receiver output line 143, bypassing
receiver 142. Receiver output line 143 provides working fluid to
pumps 124, 126 via respective pump input lines 148, 150.
[0063] In addition to main pumping units 120a, 120b, . . . , 120n,
a redundant or standby pumping unit 120' is included in the pumped
refrigerant cooling system 400 of FIG. 8. Redundant pumping unit
120' provides working fluid at a pressure in the event that any of
main pumping units 120a, 120b, . . . , 120n should become inactive.
In this manner, pumping unit 120' provides redundancy to the other
pumping units, thereby maintaining up-time and providing a cooling
function for any of the loads 122 associated with the deactivated
main pumping unit.
[0064] Redundant or standby pumping unit 120' is configured
similarly to the above-described pumping unit 120. Pumping unit
120' also includes a standby liquid line 136' and a vapor line
140'. Fluid output from liquid standby line 136' can flow to each
of loads 122a, 122b, . . . , 122n. Fluid flowing from liquid
standby line 136' flows through one of standby outlet valves 208a,
208b, . . . , 208n. Standby liquid lines 210a, 210b, . . . , 210n
connect to respective standby outlet valves 208a, 208b, . . . ,
208n and deliver fluid in place of respective pumping units 120a,
120b, . . . , 120n. Respective outlet valves 218a, 218b, . . . ,
218n can be closed to prevent fluid flow in standby liquid lines
210a, 210b, . . . , 210n from flowing into respective pumping units
120a, 120b, . . . , 120n. Vapor output from a load 122a, 122b, . .
. , 122n can be returned to pumping unit 120' via respective
standby vapor lines 214a, 214b, . . . , 214n. Standby vapor lines
214a, 214b, . . . , 214n connect to respective standby inlet valves
212a, 212b, . . . , 212n. Inlet valves 220a, 220b, . . . , 220n
associated with a respective pumping unit 120a, 120b, . . . , 120n
prevent vapor from flowing into selected respective pumping units
120a, 120b, . . . 120n. Controller 146 sends and receives
monitoring and control signals to selected components of pumped
refrigerant cooling system 400 in order to affect control of pump
refrigerant cooling system 400.
[0065] Operation of the system of FIG. 8 will be described. When a
main pumping unit 120 has become or must be deactivated because
various operational conditions of a main pumping unit 120,
redundant pumping unit 120' is activated to replace the deactivated
main pumping unit. For example, if main pumping unit 120a requires
deactivation, redundant pumping unit 120' would be activated to
provide the pumping function for deactivated main pumping unit
120a. When this occurs, redundant pumping unit 120' is substituted
into the cooling loop from load 122a to provide fluid flow to load
122a. This is accomplished through operation of valves 220a, 218a,
212a, and 208a.
[0066] For example, in order to insert redundant pumping unit 120'
into the loop to provide fluid to load 122a, inlet valve 212a and
outlet valve 208a are opened to allow fluid flow to and from
pumping unit 120'. Similarly, inlet valve 220a and outlet valve
218b are closed in order to take pumping unit 120a out of the loop
to provide fluid flow to load 122a. Once it is determined to
reactivate main pumping unit 120a, thereby requiring deactivation
of redundant pumping unit 120', a similar process to that described
above occurs.
[0067] FIG. 9 depicts a block diagram of the operation of the
pumped refrigerant cooling system 400 of FIG. 8. Control begins at
start block 230 and proceeds to decision block 232. At decision
block 232, controller 146, or other portion of the system,
determines whether a fault condition has been detected in a pumping
unit. If no fault condition has been detected, control proceeds
back to decision block 232. If a fault condition has been detected,
control proceeds to block 234. At block 234, controller 146 brings
the standby pumping unit, 120' in this example, online so that
standby pumping unit 120' can provide pressurized fluid flow.
Control then proceeds to block 236 where controller 146 places the
standby pumping unit 120' into the cooling loop of the fault
condition pumping unit 120. This occurs by opening respective inlet
valves 212 and outlet valves 208. This enables pumping unit 120' to
provide fluid flow to load 122. Control then proceeds to block 238
where the fault condition pumping unit 120 is removed from the
circuit. Controller 146 removes the fault condition pumping unit
120 by closing its corresponding inlet valve 220 and outlet valve
218 in order to take the fault condition pumping unit out of its
respective cooling loop.
[0068] Control proceeds to decision block 240. At decision block
240, controller 146, or other portions of the system, determine
when the fault condition pumping unit is determined to be operating
properly. If the fault condition pumping unit is not operating
properly, control returns to decision block 240. If the fault
condition pumping unit is operating properly, control proceeds to
block 242, and controller 146 brings the now properly operating
pumping unit 120 back online so that it can be reinserted into its
respective cooling loop to provide fluid flow of cooling fluid to
the loads 122. Once the fault condition pumping unit is brought
online, control proceeds to block 244. At block 244, the fault
condition pumping unit is placed into its respective cooling loop
by opening its respective inlet valve 220 and outlet valve 218.
Control then proceeds to block 246. At block 226, controller 146
removes the standby pumping unit 120' from the cooling loop by
closing respective standby inlet valve 212 and outlet valve 208.
Control then proceeds to block 248 which takes redundant pumping
unit 120' offline. Control then proceeds to end block 250.
[0069] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the invention, and all such modifications are intended to be
included within the scope of the invention.
* * * * *