U.S. patent application number 11/939306 was filed with the patent office on 2009-05-14 for refrigeration system.
This patent application is currently assigned to Dover Systems, Inc.. Invention is credited to Jon Scott Martin, Nicholas D. Schockley.
Application Number | 20090120117 11/939306 |
Document ID | / |
Family ID | 40622425 |
Filed Date | 2009-05-14 |
United States Patent
Application |
20090120117 |
Kind Code |
A1 |
Martin; Jon Scott ; et
al. |
May 14, 2009 |
REFRIGERATION SYSTEM
Abstract
A refrigeration system includes a low temperature portion with a
primary loop that circulates a refrigerant to
temperature-controlled storage devices operating at a low
temperature, the primary loop also including a condenser to at
least partially condense the refrigerant. The refrigeration system
also includes a medium temperature portion having a primary
refrigerant loop and a secondary coolant loop, the primary
refrigerant loop provides cooling to the secondary coolant loop
through a chiller. The secondary coolant loop has a first branch
and a second branch, where the first branch circulates coolant to
temperature-controlled storage devices operating at a medium
temperature, and the second branch circulates coolant to the
condenser of the low temperature portion.
Inventors: |
Martin; Jon Scott; (Conyers,
GA) ; Schockley; Nicholas D.; (Fayetteville,
AR) |
Correspondence
Address: |
FOLEY & LARDNER LLP
777 EAST WISCONSIN AVENUE
MILWAUKEE
WI
53202-5306
US
|
Assignee: |
Dover Systems, Inc.
|
Family ID: |
40622425 |
Appl. No.: |
11/939306 |
Filed: |
November 13, 2007 |
Current U.S.
Class: |
62/246 ; 62/434;
62/529 |
Current CPC
Class: |
F25B 2339/047 20130101;
F25B 25/005 20130101; F25B 2400/06 20130101; F25D 17/02 20130101;
F25B 7/00 20130101 |
Class at
Publication: |
62/246 ; 62/434;
62/529 |
International
Class: |
A47F 3/04 20060101
A47F003/04; F25D 17/00 20060101 F25D017/00; F25B 41/04 20060101
F25B041/04 |
Claims
1. A refrigeration system, comprising: a first portion having a
primary loop configured to circulate a refrigerant to one or more
temperature-controlled storage devices operating at a first
temperature, the primary loop also including a condenser configured
to at least partially condense the refrigerant; and a second
portion having a primary refrigerant loop and a secondary coolant
loop, the primary refrigerant loop configured to provide cooling to
the secondary coolant loop through a chiller, and the secondary
coolant loop having a first branch and a second branch, the first
branch configured to circulate coolant to one or more
temperature-controlled storage devices operating at a second
temperature and the second branch configured to circulate coolant
to the condenser of the first portion.
2. The refrigeration system of claim 1, wherein the first
temperature is less than the second temperature.
3. The refrigeration system of claim 1, wherein the coolant of the
secondary coolant loop comprises a liquid coolant.
4. The refrigeration system of claim 1, wherein the
temperature-controlled storage devices operating at a first
temperature are low temperature refrigerated display cases
configured for storage of frozen objects, and the
temperature-controlled storage devices operating at a second
temperature are medium temperature refrigerated display cases
configured for storage of refrigerated objects.
5. A refrigeration system, comprising: a first portion having a
primary loop and a secondary loop operably coupled by a first
chiller, the primary loop configured to circulate a refrigerant
through the first chiller to provide cooling to a coolant in the
secondary loop, the secondary loop having a supply portion and a
return portion, the supply portion configured to circulate the
coolant to one or more temperature-controlled storage devices
operating at a first temperature; and a second portion having a
primary loop and at least one secondary loop operably coupled by at
least one second chiller, the primary loop configured to circulate
a refrigerant through the second chiller to provide cooling to
coolant in the secondary loop, the secondary loop having a supply
portion and a return portion, the supply portion configured to
circulate the coolant to one or more temperature-controlled storage
devices operating at a second temperature; wherein the return
portion of the secondary loop of the first portion and the return
portion of the secondary loop of the second portion share a common
return header.
6. The refrigeration system of claim 5, wherein the first
temperature is less than the second temperature.
7. The refrigeration system of claim 6, wherein the return portion
of the secondary loop of the first portion diverges from the return
portion of the secondary loop of the second portion prior to the
second chiller.
8. The refrigeration system of claim 7, wherein the coolant in the
return portion of the secondary loop of the first portion pre-cools
the coolant in the return portion of the secondary loop of the
second portion.
9. The refrigeration system of claim 6, wherein the return portion
of the secondary loop of the first portion diverges from the return
portion of the secondary loop of the second portion after the
second chiller.
10. The refrigeration system of claim 9, wherein the second chiller
pre-cools the coolant in the return loop of the secondary portion
of the first portion.
11. The refrigeration system of claim 6, wherein the second chiller
comprises a plurality of second chillers, each of the second
chillers operably coupled to a secondary loop, and each of the
secondary loops operably coupled to a group of
temperature-controlled display devices.
12. The refrigeration system of claim 11, wherein each of the
groups of temperature-controlled display devices are configured to
operate at a different temperature.
13. The refrigeration system of claim 5, wherein the return header
further comprises a pump.
14. A refrigeration system, comprising: a first portion having a
first primary loop and a secondary loop operably coupled by a first
chiller, the first primary loop configured to circulate a
refrigerant through the first chiller to provide cooling to a
coolant in the secondary loop, the secondary loop having a supply
portion and a return portion, the supply portion configured to
circulate the coolant to one or more temperature-controlled storage
devices operating at a first temperature; and a second portion
including at least one modular unit containing a second primary
loop and a second chiller, the second portion further including at
least one secondary loop operably coupled to the second chiller,
the second primary loop configured to circulate a refrigerant
through the second chiller to provide cooling to coolant in the
secondary loop, the secondary loop having a supply portion and a
return portion, the supply portion configured to circulate the
coolant to one or more temperature-controlled storage devices
operating at a second temperature; wherein the return portion of
the secondary loop of the first portion and the return portion of
the secondary loop of the second portion share a common return
header.
15. The refrigeration system of claim 14, wherein the first
temperature is less than the second temperature.
16. The refrigeration system of claim 15, wherein the at least one
modular unit comprises a plurality of modular units, each having a
second chiller operably coupled to a secondary loop, and each
secondary loop configured to provide coolant to a group of
temperature controlled storage devices.
17. The refrigeration system of claim 16, wherein each of the
secondary loops share a common supply header and the common return
header.
18. The refrigeration system of claim 17, wherein the return
portion of the secondary loop of the first portion diverges from
the common return portion prior to the second chillers.
19. The refrigeration system of claim 16, wherein the return
portion of the secondary loop of the first portion diverges from
the return portion of the secondary loops of the second portion
after at least one of the second chillers.
20. A refrigeration system, comprising: a primary loop and a
secondary loop operably coupled by a chiller; the primary loop
configured to circulate a refrigerant through the chiller to
provide a chilled coolant supply in the secondary loop; the
secondary loop having a first flow path and a second flow path, the
first flow path configured to circulate a first portion of the
chilled coolant supply to one or more temperature-controlled
storage devices operating at a first temperature and to return
unchilled coolant to the chiller, and the second flow path
configured to combine a second portion of the chilled coolant
supply with a portion of the unchilled coolant for delivery as a
combined liquid coolant to one or more temperature-controlled
storage devices operating at a second temperature.
21. The refrigeration system of claim 20, wherein the first flow
path and the second flow path share a common return segment.
22. The refrigeration system of claim 21, further comprising a
tempering valve operable to mix the second portion of the chilled
coolant supply with the portion of the unchilled coolant to provide
the combined liquid coolant.
23. The refrigeration system of claim 22, wherein the first
temperature is less than the second temperature.
Description
FIELD
[0001] The present inventions relate to a refrigeration system. The
present inventions relate more particularly to a refrigeration
system having improved thermal characteristics for use with
refrigerated display cases having various temperature storage
requirements.
BACKGROUND
[0002] It is well known to provide a refrigeration system for use
with one or more temperature controlled storage devices such as a
refrigerator, freezer, refrigerated merchandiser, display case,
etc. that may be used in commercial, institutional, and residential
applications for storing or displaying refrigerated or frozen
objects. For example, it is known to provide a refrigeration system
having a refrigerant for direct expansion in a single loop
operation to provide cooling to heat exchanger such as an
evaporator or chiller. It is also known to provide a secondary
liquid coolant loop that is cooled by the chiller and then routed
to various storage devices to provide cooling to temperature
controlled objects. It is also known to provide temperature
controlled storage devices operating at various temperatures. A
refrigeration system having improved efficiency and thermal
characteristics for use with temperature controlled storage devices
operating at various temperatures is provided.
SUMMARY
[0003] The present invention relates to a refrigeration system
having a low temperature portion with a primary loop that
circulates a refrigerant to one or more temperature-controlled
storage devices operating at a low temperature, the primary loop
also including a condenser to at least partially condense the
refrigerant. The refrigeration system also includes a second
portion having a primary refrigerant loop and a secondary coolant
loop. The primary refrigerant loop provides cooling to the
secondary coolant loop through a chiller. The secondary coolant
loop has a first branch and a second branch, where the first branch
circulates coolant to temperature-controlled storage devices
operating at a medium temperature and the second branch circulates
coolant to the condenser of the low temperature portion.
[0004] The present invention also relates to a refrigeration system
that includes a low temperature portion having a primary loop and a
secondary loop operably coupled by a chiller. The primary loop
circulates refrigerant through the chiller to provide cooling to a
coolant in the secondary loop. The secondary loop has a supply
portion and a return portion. The supply portion circulates the
coolant to temperature-controlled storage devices operating at a
low temperature. The refrigeration system also includes a medium
temperature portion having a primary loop and at least one
secondary loop operably coupled by at least one chiller. The
primary loop circulates a refrigerant through the chiller to
provide cooling to coolant in the secondary loop. The secondary
loop has a supply portion and a return portion, where the supply
portion circulates the coolant to temperature-controlled storage
devices operating at a medium temperature. The return portion of
the secondary loop of the low temperature portion and the return
portion of the secondary loop of the medium temperature portion
share a common return header.
[0005] The present invention also relates to a refrigeration system
that includes a low temperature portion with a primary loop and a
secondary loop operably coupled by a chiller. The primary loop
circulates a refrigerant through the chiller to provide cooling to
a coolant in the secondary loop. The secondary loop has a supply
portion and a return portion. The supply portion circulates the
coolant to temperature-controlled storage devices operating at a
low temperature. The refrigeration system also includes a medium
temperature portion with at least one modular unit containing a
primary loop and a chiller. The medium temperature portion also
includes at least one secondary loop operably coupled to the
chiller. The primary loop circulates a refrigerant through the
chiller to provide cooling to coolant in the secondary loop. The
secondary loop has a supply portion and a return portion, where the
supply portion circulates the coolant to temperature-controlled
storage devices operating at a medium temperature, and the return
portion of the secondary loop of the low temperature portion and
the return portion of the secondary loop of the medium temperature
portion share a common return header.
[0006] The present invention also relates to a refrigeration system
having a primary loop and a secondary loop operably coupled by a
chiller. The primary loop circulates a refrigerant through the
chiller to provide a chilled coolant supply in the secondary loop.
The secondary loop has a first flow path and a second flow path.
The first flow path circulates a first portion of the chilled
coolant supply to temperature-controlled storage devices operating
at a low temperature and to return unchilled coolant to the
chiller. The second flow path combines a portion of the chilled
coolant supply with a portion of the unchilled coolant for delivery
as a combined liquid coolant to temperature-controlled storage
devices operating at a medium temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a schematic diagram of a refrigeration system
having a liquid coolant supplied to medium temperature storage
devices and for cooling a condenser associated with low temperature
storage devices, according to an exemplary embodiment.
[0008] FIG. 2 is a schematic diagram of a refrigeration system for
low and medium temperature storage devices having a common return
header for a liquid coolant, according to an exemplary
embodiment.
[0009] FIG. 3 is a schematic diagram of a refrigeration system for
low and medium temperature storage devices having a common return
header and pre-cooling for liquid coolant used with the low
temperature storage devices, according to an exemplary
embodiment.
[0010] FIG. 4 is a schematic diagram of the refrigeration system of
FIG. 2 and including modular condensing units for the medium
temperature storage devices, according to an exemplary
embodiment.
[0011] FIG. 5 is a schematic diagram of the refrigeration system of
FIG. 3 and including modular condensing units for the medium
temperature storage devices, according to an exemplary
embodiment.
[0012] FIG. 6 is a schematic diagram of a refrigeration system for
low and medium temperature storage devices that uses a liquid
coolant supply to the low temperature storage devices to temper a
coolant supply to the medium temperature storage devices, according
to an exemplary embodiment.
DETAILED DESCRIPTION
[0013] Referring to the FIGURES, a refrigeration system is shown
for use with a plurality of temperature controlled storage devices,
where the storage devices may have different storage temperature
requirements (e.g. "low temperature," such as approximately
-20.degree. F., and "medium temperature," such as approximately
25.degree. F.). However, the various temperatures of the storage
devices, refrigerants and liquid coolants illustrated or described
in the various embodiments, are shown by way of example only. A
wide variety of other temperatures and temperature ranges may be
used to suit any particular application and are intended to be
within the scope of this disclosure. Also, the various flow rates,
capacity and balancing of coolants and refrigerants are described
by way of example and may be modified to suit a wide variety of
applications depending on the number of storage devices, the
temperature requirements of the storage devices, etc.
[0014] Referring to FIG. 1, a refrigeration system 100 includes a
first portion shown as a medium temperature portion 110 for use
with temperature controlled storage devices having a "medium"
storage temperature requirement (such as, for example, 25.degree.
F. and referred to herein as medium temperature storage devices),
and a low temperature portion 160 for use with temperature
controlled storage devices having a "low" storage temperature
requirement (such as, for example, -20.degree. F. and referred to
herein as low temperature storage devices), according to an
exemplary embodiment.
[0015] The low temperature portion 160 is shown to include a
cooling loop 162 (e.g. formed from suitable conduits or passageways
such as pipes, fittings, tubing, etc.) having a refrigerant (e.g. a
direct expansion type refrigerant such as R-404A, or carbon dioxide
or other suitable refrigerant) as a cooling medium. The refrigerant
is compressed by a compressor 164 to a high temperature and high
pressure state, and is then cooled in a condenser 166, and then
expanded by an expansion device (such as an expansion valve 170) to
provide a source of cooling to a heat exchanger operating as a
cooling element (such as a cooling coil, evaporator, etc.) in one
or more low temperature storage devices (shown for example as three
low temperature storage devices 172). According to the illustrated
embodiment, the low temperature portion is shown to include a
receiver 168. According to alternative embodiments, a receiver may
be omitted. According to other alternative embodiments, other
components or equipment such as a sub-cooler, liquid line or
suction line filter, oil management system, etc. may be included in
the system.
[0016] The medium temperature portion 110 is shown to include a
first (or primary) cooling loop 112 (e.g. formed from suitable
conduits or passageways such as pipes, fittings, tubing, etc.)
having a refrigerant (e.g. a direct expansion type refrigerant such
as R404A) as a cooling medium. The refrigerant is compressed by a
compressor 114 to a high temperature and high pressure state, and
is then cooled in a condenser 116, then expanded in an expansion
device (such as an expansion valve 118) to provide a source of
cooling to a heat exchanger (shown as a chiller 120). According to
one embodiment, the components of first cooling loop 112 operate to
provide refrigerant at a temperature of approximately 13.degree. F.
to the chiller.
[0017] The medium temperature portion 110 also includes a second
(or secondary) cooling loop 130 having a first portion 132 and a
second portion 134 (e.g. circuits, branches, flow paths,
etc.--formed from suitable conduits or passageways such as pipes,
fittings, tubing, etc.) for circulation of a liquid coolant (such
as water, glycol, etc.) as a cooling medium by a pump 136.
According to one embodiment, the second cooling loop 130 is cooled
by the refrigerant in chiller 120 to a temperature of approximately
20.degree. F. The liquid coolant is circulated through the first
portion 132 to provide cooling to a heat exchanger within one or
more medium temperature storage devices (shown for example as three
medium temperature storage devices 136). The liquid coolant is also
circulated through the second portion 134 to provide cooling to
condenser 166 of the low temperature portion of the system.
[0018] One of the advantages of the exemplary embodiment
illustrated in FIG. 1 is that cooling for the condenser 166 of the
low temperature portion 160 of the system 100 may be provided by
the liquid coolant of the medium temperature portion 110 of the
system 100, thereby eliminating the need for a separate cooling
system (e.g. a separate water-filled cooling loop routed to a
remote heat exchanger) for cooling the condenser 166. Another
advantage is to provide energy efficient, low temperature
condensing to low temperature portion 160 of the system.
[0019] Referring to FIG. 2, a refrigeration system 200 for low and
medium temperature storage devices having a common return header
for a liquid coolant, is shown according to another exemplary
embodiment. Refrigeration system 200 includes a first portion shown
as a low temperature portion 210 for use with low temperature
storage devices, and a medium temperature portion 260 for use with
medium temperature storage devices.
[0020] The low temperature portion 210 is shown to include a first
(or primary) cooling loop 212 (e.g. formed from suitable conduits
or passageways such as pipes, fittings, tubing, etc.) having a
refrigerant (e.g. a direct expansion type refrigerant) as a cooling
medium. The refrigerant is compressed by a compressor 214 to a high
temperature and high pressure state, and is then cooled in a
condenser 216, then expanded by an expansion device (such as an
expansion valve 218) to provide a source of cooling to a heat
exchanger (shown as a chiller 220). According to one embodiment,
the components of first cooling loop 212 operate to provide
refrigerant at a temperature of approximately 13.degree. F. to the
chiller 220.
[0021] Low temperature portion 210 also includes a second (or
secondary) cooling loop 230 (e.g. formed from suitable conduits or
passageways such as pipes, fittings, tubing, etc.) for circulation
of a liquid coolant as a cooling medium by a pump 232. According to
one embodiment, the liquid coolant in the second cooling loop 230
is cooled by the refrigerant in chiller 220 to a temperature of
approximately 20.degree. F. and is circulated to provide cooling to
a heat exchanger within one or more low temperature storage devices
(shown for example as three low temperature storage devices 236).
The secondary cooling loop includes a supply portion 238 (i.e. the
portion between the chiller 220 and the storage devices 236 and
"upstream" of the storage devices 236, and a return portion 240
(i.e. the portion between the storage devices 236 and the pump 232
and "downstream" from low temperature storage devices 236) and the
liquid coolant returns to chiller 220 with a temperature of
approximately 30.degree. F.
[0022] The medium temperature portion 260 of the system 200 is
shown to include a first (or primary) cooling loop 262 (e.g. formed
from suitable conduits or passageways such as pipes, tubing, etc.)
having a refrigerant as a cooling medium to provide cooling to one
or more chillers. The refrigerant is compressed by a compressor 264
to a high temperature and high pressure state, and is then cooled
in a condenser 266, then expanded in an expansion device (shown as
expansion valves 268) to provide a source of cooling to heat
exchangers (shown for example as two chillers 270, 272). According
to one embodiment, the components of first cooling loop 262 operate
to provide refrigerant at a temperature of approximately 18.degree.
F. to the chillers.
[0023] The medium temperature portion 260 also includes a second
(or secondary) cooling loop 274, 276 associated with each of
chillers 270, 272 (e.g. formed from suitable conduits or
passageways such as pipes, fittings, tubing, etc.) for circulation
of a liquid coolant as a cooling medium by pump 232. Although the
medium temperature portion 260 of the system 200 is shown to have
two chillers for use in cooling two groups of storage devices, any
number of chillers may be used to provide cooling to any number of
groups of storage devices. According to one embodiment, the
secondary cooling loops 274, 276 are cooled by the refrigerant in
chillers 270, 272 to a temperature of approximately 25.degree. F.
and the liquid coolant returns to chillers 270, 272 with a
temperature of approximately 30.degree. F. Secondary cooling loop
274 is associated with chiller 270 to provide cooling to a heat
exchanger within one or more medium temperature storage devices
from a first group (shown for example as three medium temperature
storage devices 278) and secondary cooling loop 276 is associated
with chiller 272 to provide cooling to a heat exchanger within one
or more medium temperature storage devices from a second group
(shown for example as three medium temperature storage devices
280). Secondary loops 274, 276 each have a return portion that
share a common flow path (e.g. manifold, etc. and shown as a header
282) with one another, and with the return portion 240 of the
secondary loop 230 for the low temperature portion 210. The return
portions for the low and medium temperature portions of the system
then diverge into separate branches 242, 243 to complete their
respective loops and return the liquid coolant to their respective
chillers.
[0024] One of the advantages of the exemplary embodiment
illustrated in FIG. 2 is that liquid coolant returned from the low
temperature storage devices 236 may be used to pre-cool the
returned liquid coolant in the medium temperature loops 274, 276
prior to entering the medium temperature chillers 270, 272.
According to the illustrated embodiment, the liquid coolant return
242 from the header 282 to the low temperature portion 210 of the
system 200 branches from the header 282 downstream of the medium
temperature storage devices 278, 280, but upstream of the medium
temperature chillers 270, 272. Another advantage is the ability to
allow multiple temperature fluid portions of the system to share a
common pump station
[0025] Referring to FIG. 3, a refrigeration system 300 for low and
medium temperature storage devices having a common return header
for a liquid coolant and pre-cooling for the liquid coolant
returned from the low temperature storage devices, is shown
according to another exemplary embodiment. Refrigeration system 300
includes a first portion shown as a low temperature portion 310 for
use with low temperature storage devices, and a second portion
shown as a medium temperature portion 360 for use with medium
temperature storage devices.
[0026] The low temperature portion 310 is shown to include a first
(or primary) cooling loop 312 having a refrigerant as a cooling
medium. The refrigerant is compressed by a compressor 314 to a high
temperature and high pressure state, and is then cooled in a
condenser 316, then expanded by an expansion device (such as an
expansion valve 318) to provide a source of cooling to a heat
exchanger (shown as a chiller 320). According to one embodiment,
the components of first cooling loop 312 operate to provide
refrigerant at a temperature of approximately 13.degree. F. to the
chiller 320.
[0027] Low temperature portion 310 also includes a second (or
secondary) cooling loop 330 for circulation of a liquid coolant as
a cooling medium by a pump 332. According to one embodiment, the
liquid coolant in the second cooling loop 330 is cooled by the
refrigerant in chiller 320 to a temperature of approximately
20.degree. F. and is circulated to provide cooling to a heat
exchanger within one or more low temperature storage devices (shown
for example as three low temperature storage devices 336). The
secondary cooling loop includes a supply portion 338 and a return
portion 340.
[0028] The medium temperature portion 360 of the system 300 is
shown to include a first (or primary) cooling loop 362 having a
refrigerant as a cooling medium to provide cooling to one or more
chillers. The refrigerant is compressed by a compressor 364 to a
high temperature and high pressure state, and is then cooled in a
condenser 366, then expanded in an expansion device (shown as
expansion valves 368) to provide a source of cooling to the heat
exchangers (shown for example as two chillers 370, 372). According
to one embodiment, the components of first cooling loop 362 operate
to provide refrigerant at a temperature of approximately 18.degree.
F. to the chillers 370, 372.
[0029] The medium temperature portion 360 also includes a second
(or secondary) cooling loop 374, 376 associated with each of
chillers 370, 372 for circulation of a liquid coolant by pump 332.
Although the medium temperature portion 360 of the system 300 is
shown to have two chillers for use in cooling two groups of storage
devices, any number of chillers may be used to provide cooling to
any number of groups of storage devices. According to one
embodiment, the secondary cooling loops 374, 376 are cooled by the
refrigerant in chillers 370, 372 to a temperature of approximately
25.degree. F. and the liquid coolant returns to chillers 370, 372
with a temperature of approximately 30.degree. F. Secondary cooling
loop 374 is associated with chiller 370 to provide cooling to a
heat exchanger within one or more medium temperature storage
devices 378 from a first group, and secondary cooling loop 376 is
associated with chiller 372 to provide cooling to a heat exchanger
within one or more medium temperature storage devices 380 from a
second group. Secondary loops 374, 376 each have a return portion
that share a common header 382 with one another, and with the
return portion 340 of the secondary loop 330 for the low
temperature portion 310. According to an alternative embodiment,
the secondary cooling loops may also share a common supply
header.
[0030] According to the illustrated embodiment, the return portion
340 of the secondary loop 330 for the low temperature portion 310
is routed through one or both of chillers 370, 372 (shown for
example as both chillers 370, 372) to pre-cool the liquid coolant
before entering the chiller 320 of the low temperature portion 310.
The return portion 340 for the low temperature portion 310 of the
system 300 then diverges from the supply side of one or both medium
temperature secondary cooling loops 374, 376 (shown for example as
both cooling loops) into a separate branch 342 to complete its
return loop to provide the liquid coolant to the chiller 320 of the
low temperature portion 310 of the system 300. According to the
exemplary embodiment, the liquid coolant supplied to the medium
temperature storage devices 378, 380 and the liquid coolant
returned to the chiller 320 of the low temperature portion 310 of
the system 300 is approximately 25.degree. F.
[0031] One of the advantages of the exemplary embodiment
illustrated in FIG. 3 is that chiller(s) from the medium
temperature system 360 may be used to pre-cool the liquid coolant
returned from the low temperature storage device(s) 336 prior to
entering the low temperature chiller 320.
[0032] Referring to FIG. 4, a refrigeration system 400 for low and
medium temperature storage devices having a common return header
for a liquid coolant, and modular condensing units to provide
cooling to each of the groups of medium temperature storage
devices, is shown according to another exemplary embodiment.
Refrigeration system 400 includes a first portion shown as a low
temperature portion 410 for use with low temperature storage
devices, and a medium temperature portion 460 for use with medium
temperature storage devices.
[0033] The low temperature portion 410 is shown to include a first
(or primary) cooling loop 412 having a refrigerant as a cooling
medium. The refrigerant is compressed by a compressor 414 to a high
temperature and high pressure state, and is then cooled in a
condenser 416, then expanded by an expansion device (such as an
expansion valve 418) to provide a source of cooling to a heat
exchanger (shown as a chiller 420). According to one embodiment,
the components of first cooling loop 412 operate to provide
refrigerant at a temperature of approximately 13.degree. F. to the
chiller 420.
[0034] Low temperature portion 410 also includes a second (or
secondary) cooling loop 430 for circulation of a liquid coolant by
a pump 432. According to one embodiment, the liquid coolant in the
second cooling loop 430 is cooled by the refrigerant in chiller 420
to a temperature of approximately 20.degree. F. and is circulated
to provide cooling to a heat exchanger within one or more low
temperature storage devices (shown for example as three low
temperature storage devices 436). The secondary cooling loop
includes a supply portion 438, and a return portion 440 and the
liquid coolant returns to chiller 420 with a temperature of
approximately 30.degree. F.
[0035] The medium temperature portion 460 of the system 400 shown
to include one or more modular, independent, and self-contained
condensing units (e.g. packages, modules, etc.--shown for example
as two modular condensing units 461 associated with each group of
medium temperature storage devices. Each modular condensing unit
includes a first (or primary) cooling loop 462 formed from suitable
conduits or passageways such as pipes, fittings, tubing, etc.)
having a refrigerant as a cooling medium to provide cooling to one
or more chillers. The refrigerant is compressed by a compressor 464
to a high temperature and high pressure state, and is then cooled
in a condenser 466, then expanded in an expansion device (shown as
expansion valves 468) to provide a source of cooling to a heat
exchanger (shown for example as a chiller 470). According to one
embodiment, the components of each modular condensing unit 461
operate to provide refrigerant at a temperature of approximately
18.degree. F. to the chillers 470. According to alternative
embodiments, the modular condensing units may be configured to
operate at different temperatures for use with groups of
temperature controlled storage devices designed to operate at
different temperatures. Further, any number of modular condensing
units may be provided for use in connection with corresponding
groups of temperature controlled storage devices.
[0036] The medium temperature portion 460 also includes a second
(or secondary) cooling loop 474, 476 associated with each of
chillers 470 of the modular condensing units 461 for circulation of
a liquid coolant by pump 432. According to one embodiment where the
modular condensing units are operating at approximately the same
temperature, the secondary cooling loops 474, 476 are cooled by the
refrigerant in chillers 470 to a temperature of approximately
25.degree. F. and the liquid coolant returns to chillers 470 with a
temperature of approximately 30.degree. F. Secondary loops 474, 476
each have a return portion that share a common flow path (e.g.
manifold, etc.--shown as a return header 482) with one another, and
with the return portion 440 of the secondary loop 430 for the low
temperature portion 410. The return portions for the low and medium
temperature portions of the system then diverge into separate
branches 442, 443 to complete their respective loops and return the
liquid coolant to their respective chillers. Secondary loops 474,
476 are shown to have separate supply portions, however the supply
portions may be configured as a common supply header and the
modular condensing units may be readily attachable and detachable
(e.g. by suitable fittings, such as quick-connect devices, etc.)
with the common supply and return headers (e.g. in a "plug and
play" type manner, etc.) to facilitate maintenance, or for
increasing or decreasing capacity, etc.
[0037] One of the advantages of the exemplary embodiment
illustrated in FIG. 4 is that liquid coolant returned from the low
temperature storage devices 436 may be used to pre-cool the
returned liquid coolant in the medium temperature return header 482
prior to entering the chillers 470 of the modular condensing units
461. In addition, the benefits of the common return header may be
combined with the advantages of the modularity of the primary
cooling loops.
[0038] Referring to FIG. 5, a refrigeration system 500 for low and
medium temperature storage devices having a common return header
for a liquid coolant, and pre-cooling for the liquid coolant
returned from the low temperature storage devices, and modular
condensing units to provide cooling to each of the groups of medium
temperature storage devices, is shown according to another
exemplary embodiment. Refrigeration system 500 includes a first
portion shown as a low temperature portion 510 for use with low
temperature storage devices, and a second portion shown as a medium
temperature portion 560 for use with medium temperature storage
devices.
[0039] The low temperature portion 510 is shown to include a first
(or primary) cooling loop 512 having a refrigerant as a cooling
medium. The refrigerant is compressed by a compressor 514 to a high
temperature and high pressure state, and is then cooled in a
condenser 516, then expanded by an expansion device (such as an
expansion valve 518) to provide a source of cooling to a heat
exchanger (shown as a chiller 520). According to one embodiment,
the components of first cooling loop 512 operate to provide
refrigerant at a temperature of approximately 13.degree. F. to the
chiller 520.
[0040] Low temperature portion 510 also includes a second (or
secondary) cooling loop 530 for circulation of a liquid coolant as
a cooling medium by a pump 532. According to one embodiment, the
liquid coolant in the second cooling loop 530 is cooled by the
refrigerant in chiller 520 to a temperature of approximately
20.degree. F. and is circulated to provide cooling to a heat
exchanger within one or more low temperature storage devices (shown
for example as three low temperature storage devices 536). The
secondary cooling loop includes a supply portion 538 and a return
portion 540.
[0041] The medium temperature portion 560 of the system 500 is
shown to include one or more modular condensing units (shown for
example as two modular condensing units 561) associated with each
group of medium temperature storage devices. Each modular
condensing unit includes a first (or primary) cooling loop 562
having a refrigerant to provide cooling to a chiller. The
refrigerant is compressed by a compressor 564 to a high temperature
and high pressure state, and is then cooled in a condenser 566,
then expanded in an expansion device (shown as expansion valves
568) to provide a source of cooling to heat a exchanger (shown for
example as chiller 570). According to one embodiment, the
components of each modular condensing unit 561 operate to provide
refrigerant at a temperature of approximately 18.degree. F. to the
chillers. According to alternative embodiments, the modular
condensing units may operate at different temperatures for
providing a desired temperature to their respective groups of
temperature controlled storage devices.
[0042] The medium temperature portion 560 also includes a second
(or secondary) cooling loop 574, 576 associated with each of
chillers 570 of the modular condensing units for circulation of a
liquid coolant by pump 532. According to one embodiment where the
modular condensing units are operated at approximately the same
temperature, the secondary cooling loops 574, 576 are cooled by the
refrigerant in chillers 570 to a temperature of approximately
25.degree. F. and the liquid coolant returns to chillers 570 with a
temperature of approximately 30.degree. F. Secondary loops 574, 576
each have a return portion that share a common flow path (e.g.
return header 582) with one another, and with the return portion
540 of the secondary loop 530 for low temperature portion 510.
Secondary loops 574, 576 are shown to have separate supply
portions, however the supply portions may be configured as a common
header and the modular condensing units may be readily attachable
and detachable as previously described.
[0043] According to the illustrated embodiment, the return portion
540 of the secondary loop 530 for the low temperature portion 510
is routed through one or both of chillers 570 (shown for example as
both chillers 570) of modular condensing units 561 to pre-cool the
liquid coolant before entering the chiller 520 of the low
temperature portion 510. The return portion for the low temperature
portion 510 of the system 500 then diverges from the supply side of
one or both medium temperature secondary cooling loops 574, 576
(shown for example as both cooling loops 574, 576) into a separate
branch 542 to complete its return loop 540 to provide the liquid
coolant to the chiller 520 of the low temperature portion 510 of
the system 500. According to the exemplary embodiment, the liquid
coolant supplied to the medium temperature storage devices 578, 580
and the liquid coolant returned to the chiller 520 of the low
temperature portion 510 of the system 500 is approximately
25.degree. F.
[0044] One of the advantages of the exemplary embodiment
illustrated in FIG. 5 is that one or more chillers from the modular
condensing units of the medium temperature system may be used to
pre-cool the returned liquid coolant from the low temperature
storage device prior to returning to the low temperature chiller.
In addition, the benefits of the common return header and
pre-cooling of the low temperature liquid coolant return may be
combined with the advantages of the modularity of the medium
temperature primary cooling loops.
[0045] Referring to FIG. 6, a refrigeration system 600 includes a
first (or primary) cooling loop 610 having a refrigerant as a
cooling medium. The refrigerant is compressed by a compressor 614
to a high temperature and high pressure state, and is then cooled
in a condenser 616, then expanded in an expansion device (such as
an expansion valve 618) to provide a source of cooling to a heat
exchanger (shown as a chiller 620). According to one embodiment,
the components of first cooling loop 610 operate to provide
refrigerant at a temperature of approximately 13.degree. F. to the
chiller 620.
[0046] Refrigeration system 600 also includes a second (or
secondary) cooling loop 630 having a first flow path 634 and a
second flow path 636 (e.g. formed from suitable conduits or
passageways such as pipes, fittings, tubing, etc.) for circulation
of a liquid coolant as a cooling medium by a pump 632. According to
one embodiment, the liquid coolant in the second cooling loop 630
is cooled by the refrigerant in chiller 620 to a temperature of
approximately 20.degree. F. to provide a chilled liquid coolant
supply. A first portion of the chilled liquid coolant supply is
directed into a supply portion 638 of the first flow path 634 to
provide cooling to a heat exchanger within low temperature storage
devices 650, and then as un-chilled liquid coolant through a return
portion 640 back to chiller 620. A portion of the (un-chilled)
liquid coolant returned from the low temperature storage devices
650 is also directed into (i.e. mixed with) a second portion of the
chilled liquid coolant supply in the second flow path 636 via
branch line 642 to deliver a supply of coolant to medium
temperature storage devices 660. The second portion of the chilled
liquid coolant supply is directed into the second flow path 636
which includes a tempering valve 644 to regulate the temperature of
the combined liquid coolant supply (e.g. by modulating the position
of valve 644 to control the mixing of the chilled coolant and the
un-chilled coolant) to the medium temperature storage devices 660.
For example, according to one embodiment, the temperature of the
liquid coolant supplied to the first and second flow paths is
approximately 20.degree. F., and the temperature of the coolant
returned from the low temperature storage devices and routed to the
second flow path is approximately 28.degree. F., and the tempering
valve 644 operates to permit passage of sufficient liquid coolant
supply to reduce the combined liquid coolant temperature from
approximately 28.degree. F. to approximately 25.degree. F. for
supply to the medium temperature storage devices 660.
[0047] One of the advantages of the exemplary embodiment
illustrated in FIG. 6 is that a single primary loop and chiller may
be used to provide cooling to storage devices having both low and
medium temperature requirements.
[0048] According to any exemplary embodiment, the refrigeration
system may also include suitable control and regulation components
and equipment, such as valves (e.g. solenoid valves, manual and
electronic balancing valves, pressure regulation valves, flow
regulation valves, superheat control valves, etc.), temperature and
pressure monitoring devices (e.g. thermocouples, resistance
temperature detectors (RTDs), gauges, transducers, transmitters,
sensors, etc.) operable to monitor a condition of the refrigerant,
coolant or air space in the control devices and to send a signal
representative of temperature and/or pressure to a control device
of the system. The system may also include suitable control
equipment (e.g. controllers) such as programmable logic
controllers, microprocessors, etc. operable to receive the
temperature and pressure signals and to operate the valves and
other equipment (e.g. compressors, etc.) according to a
predetermined control scheme to operate the system in a suitable
manner to maintain a desired temperature within the temperature
controlled storage devices. The control system may be provided
locally (e.g. proximate other equipment of the system), or the
control device may be provided at a remote location for controlling
the operation of the system and/or other systems that may be in use
at a facility. The control system may also be configured to control
other operational requirements of the system, such as defrosting of
the cooling elements within the temperature controlled storage
devices (e.g. by temporarily interrupting the flow of coolant in a
"time-off" manner, or initiating operation of electrical defrost
elements, or by directing the flow of a warm fluid (e.g. hot
refrigerant gas, heated liquid coolant, etc.) through the cooling
elements, etc.).
[0049] It is important to note that the construction and
arrangement of the elements and embodiments of the refrigeration
system provided herein are illustrative only. Although only a few
exemplary embodiments of the present invention have been described
in detail in this disclosure, those skilled in the art who review
this disclosure will readily appreciate that many modifications are
possible in these embodiments (such as variations in features such
as components, coolant compositions, heat sources, orientation and
configuration of storage devices, location of components and
sensors of the cooling and control systems; variations in sizes,
structures, shapes, dimensions and proportions of the components of
the system, use of materials, colors, combinations of shapes, etc.)
without materially departing from the novel teachings and
advantages of the invention. For example, closed or open space
refrigeration systems may be used having either horizontal or
vertical access openings, and cooling elements may be provided in
any number, size, orientation and arrangement to suit a particular
refrigeration system. According to other alternative embodiments,
the refrigeration system may be used with any device using a
refrigerant or coolant for transferring heat from one space to be
cooled to another space or source designed to receive the rejected
heat and may include commercial, institutional or residential
refrigeration systems. Further, it is readily apparent that
variations of the refrigeration system and its components and
elements may be provided in a wide variety of types, shapes, sizes
and performance characteristics, or provided in locations external
or partially external to the refrigeration system. For example,
components of a cooling system may be provided as rack-mounted
system, or as a custom-installed hard-piped system, or may be
provided as a modular unit or package. Accordingly, all such
modifications are intended to be within the scope of the
inventions.
[0050] The order or sequence of any process or method steps may be
varied or re-sequenced according to alternative embodiments. In the
claims, any means-plus-function clause is intended to cover the
structures described herein as performing the recited function and
not only structural equivalents but also equivalent structures.
Other substitutions, modifications, changes and omissions may be
made in the design, operating configuration and arrangement of the
preferred and other exemplary embodiments without departing from
the spirit of the inventions as expressed in the appended
claims.
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