U.S. patent application number 11/021036 was filed with the patent office on 2006-06-22 for microchannnel evaporator assembly.
This patent application is currently assigned to Hussmann Corporation. Invention is credited to Doug McAlpine, Justin P. Merkys, Norman E. Street, Phil K. Zerbe.
Application Number | 20060130517 11/021036 |
Document ID | / |
Family ID | 36594001 |
Filed Date | 2006-06-22 |
United States Patent
Application |
20060130517 |
Kind Code |
A1 |
Merkys; Justin P. ; et
al. |
June 22, 2006 |
Microchannnel evaporator assembly
Abstract
The present invention provides a unit cooler adapted for use in
a refrigerated environment. The unit cooler includes a housing
adapted to be positioned within the refrigerated environment and at
least one microchannel evaporator coil supported by the housing.
The at least one microchannel evaporator coil includes an inlet
manifold and an outlet manifold. The inlet manifold has an inlet
port for receiving refrigerant, and the outlet manifold has an
outlet port for discharging the refrigerant.
Inventors: |
Merkys; Justin P.;
(Palatine, IL) ; McAlpine; Doug; (Bartlett,
IL) ; Street; Norman E.; (O'Fallon, MO) ;
Zerbe; Phil K.; (Lombard, IL) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH, LLP
100 E WISCONSIN AVENUE
MILWAUKEE
WI
53202
US
|
Assignee: |
Hussmann Corporation
Bridgeton
MO
|
Family ID: |
36594001 |
Appl. No.: |
11/021036 |
Filed: |
December 22, 2004 |
Current U.S.
Class: |
62/515 ; 165/177;
62/524 |
Current CPC
Class: |
F28F 2260/02 20130101;
F25B 39/022 20130101; F28F 9/0275 20130101; F28F 1/022 20130101;
F28D 1/05383 20130101; F28F 9/262 20130101; F25B 2500/01
20130101 |
Class at
Publication: |
062/515 ;
062/524; 165/177 |
International
Class: |
F25D 21/12 20060101
F25D021/12; F28F 1/00 20060101 F28F001/00; F25B 39/02 20060101
F25B039/02 |
Claims
1. A unit cooler adapted for use in a refrigerated environment, the
unit cooler comprising: a housing adapted to be positioned within
the refrigerated environment; and at least one microchannel
evaporator coil supported by the housing, the at least one
microchannel evaporator coil including an inlet manifold and an
outlet manifold, the inlet manifold having an inlet port for
receiving refrigerant, and the outlet manifold having an outlet
port for discharging the refrigerant.
2. The unit cooler of claim 1, further comprising at least one fan
supported by the housing, the fan being configured to generate an
airflow at least partially through the microchannel evaporator
coil.
3. The unit cooler of claim 1, wherein the microchannel evaporator
coil includes a plurality of fins spaced thereon between 12 and 24
fins per inch.
4. The unit cooler of claim 1, wherein the microchannel evaporator
coil includes a plurality of microchannels fluidly connecting the
inlet manifold and the outlet manifold, the microchannels measuring
between about 0.5 mm by about 0.5 mm and about 4 mm by about 4 mm
in cross-section.
5. A unit cooler adapted for use in a refrigerated environment, the
unit cooler comprising: a housing adapted to be positioned within
the refrigerated environment; a first microchannel evaporator coil
supported by the housing and configured such that the refrigerant
makes at least one pass therethrough; and a second microchannel
evaporator coil supported by the housing and fluidly coupled with
the first microchannel evaporator coil, the second microchannel
evaporator coil being configured such that the refrigerant makes at
least one pass through the second microchannel evaporator coil
after making at least one pass through the first microchannel
evaporator coil.
6. The unit cooler of claim 5, further comprising at least one fan
supported by the housing, the fan being configured to generate an
airflow at least partially through at least one of the first and
second microchannel evaporator coils.
7. The unit cooler of claim 5, wherein at least one of the first
and second microchannel evaporator coils include a plurality of
fins spaced thereon between 12 and 24 fins per inch.
8. The unit cooler of claim 5, wherein at least one of the first
and second microchannel evaporator coils include a plurality of
microchannels fluidly connecting the inlet manifold and the outlet
manifold, the microchannels measuring between about 0.5 mm by about
0.5 mm and about 4 mm by about 4 mm in cross-section.
9. The unit cooler of claim 5, wherein the first and second
microchannel evaporator coils each include an inlet manifold and an
outlet manifold, and wherein the outlet manifold of the first
microchannel evaporator coil is fluidly connected with the inlet
manifold of the second microchannel evaporator coil.
10. The unit cooler of claim 9, wherein the respective inlet
manifolds each include at least one inlet port, and the respective
outlet manifolds each include at least one outlet port, and wherein
the outlet port of the first microchannel evaporator coil is
coupled to the inlet port of the second microchannel evaporator
coil.
11. The unit cooler of claim 5, wherein the second microchannel
evaporator coil is in a fluid series connection with the first
microchannel evaporator coil.
12. A unit cooler adapted for use in a refrigerated environment,
the unit cooler comprising: a housing adapted to be positioned
within the refrigerated environment; a first microchannel
evaporator coil supported by the housing and configured such that
refrigerant makes at least one pass therethrough; a second
microchannel evaporator coil supported by the housing and
configured such that the refrigerant makes at least one pass
therethrough; a distributor fluidly coupled with the first and
second microchannel evaporator coils, the distributor being
configured to deliver the refrigerant to the first and second
microchannel evaporator coils; an outlet header fluidly coupled
with the first and second microchannel evaporator coils, the outlet
header being configured to receive refrigerant from the first and
second microchannel evaporator coils.
13. The unit cooler of claim 12, further comprising at least one
fan supported by the housing, the fan being configured to generate
an airflow at least partially through at least one of the first and
second microchannel evaporator coils.
14. The unit cooler of claim 12, wherein at least one of the first
and second microchannel evaporator coils include a plurality of
fins spaced thereon between 12 and 24 fins per inch.
15. The unit cooler of claim 12, wherein the first and second
microchannel evaporator coils each include an inlet manifold and an
outlet manifold.
16. The unit cooler of claim 15, wherein the inlet and outlet
manifolds of the first and second microchannel evaporator coils are
fluidly connected by a plurality of microchannels, the
microchannels measuring between about 0.5 mm by about 0.5 mm and
about 4 mm by about 4 mm in cross-section.
17. The unit cooler of claim 15, wherein the inlet manifolds of the
first and second microchannel condenser coils are fluidly connected
with the distributor.
18. The unit cooler of claim 17, wherein the inlet manifolds of the
first and second microchannel evaporator coils each include at
least one inlet port, the at least one inlet port of the first
microchannel evaporator coil being coupled to the distributor, and
the at least one inlet port of the second microchannel evaporator
coil being coupled to the distributor.
19. The unit cooler of claim 15, wherein the outlet manifolds of
the first and second microchannel evaporator coils are fluidly
connected with the outlet header.
20. The unit cooler of claim 19, wherein the outlet manifolds of
the first and second microchannel evaporator coils each include at
least one outlet port, the at least one outlet port of the first
microchannel evaporator coil being coupled to the outlet header,
and the at least one outlet port of the second microchannel
evaporator coil being coupled to the outlet header.
21. A method of assembling a unit cooler adapted for use in a
refrigerated environment, the method comprising: providing a first
microchannel evaporator coil configured such that refrigerant makes
at least one pass therethrough; fluidly connecting the first
microchannel evaporator coil to a second microchannel evaporator
coil configured such that the refrigerant makes at least one pass
through the second microchannel evaporator coil after making at
least one pass through the first microchannel evaporator coil; and
substantially enclosing the first and second microchannel
evaporator coils in a housing.
22. The method of claim 21, further comprising positioning at least
one fan over at least one of the first and second microchannel
evaporator coils, the fan being configured to generate an airflow
through the at least one of the first and second microchannel
evaporator coils.
23. The method of claim 21, wherein fluidly connecting the first
microchannel evaporator coil to the second microchannel evaporator
coil includes coupling an outlet port of the first microchannel
evaporator coil with an inlet port of the second microchannel
evaporator coil.
24. The method of claim 21, further comprising: calculating a total
refrigeration capacity of the refrigeration system; and determining
how many microchannel evaporator coils should be fluidly
interconnected.
25. A method of assembling a unit cooler adapted for use in a
refrigerated environment, the method comprising: providing a first
microchannel evaporator coil configured such that refrigerant makes
at least one pass therethrough; providing a second microchannel
evaporator coil configured such that the refrigerant makes at least
one pass therethrough; fluidly connecting a distributor to the
first and second microchannel evaporator coils, the distributor
being configured to deliver the refrigerant to the first and second
microchannel evaporator coils; fluidly connecting an outlet header
to the first and second microchannel evaporator coils, the outlet
header being configured to receive the refrigerant from the first
and second microchannel evaporator coils; and substantially
enclosing the first and second microchannel evaporator coils in a
housing.
26. The method of claim 25, further comprising positioning at least
one fan over at least one of the first and second microchannel
evaporator coils, the fan being configured to generate an airflow
through the at least one of the first and second microchannel
evaporator coils.
27. The method of claim 25, wherein fluidly connecting the
distributor to the first and second microchannel evaporator coils
includes coupling respective inlet ports of the first and second
microchannel evaporator coils to the distributor.
28. The method of claim 25, wherein fluidly connecting the outlet
header to the first and second microchannel evaporator coils
includes coupling respective outlet ports of the first and second
microchannel evaporator coils to the outlet header.
29. The method of claim 25, further comprising: calculating a total
refrigeration capacity of the refrigeration system; and determining
how many microchannel evaporator coils should be fluidly
interconnected.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to evaporator coils, and
more particularly to evaporator coils for use in large-scale
refrigeration systems.
BACKGROUND OF THE INVENTION
[0002] Typical large-scale refrigeration systems, such as those
utilized in large-scale refrigerated environments (e.g., walk-in
coolers or refrigerated warehouses), often include a single, large
conventional fin-and-tube evaporator coil. Such a conventional
fin-and-tube evaporator coil often displays poor efficiencies in
transferring heat from an airflow passing through the coil to the
refrigerant passing through the coil. As a result, the fin-and-tube
evaporator coil can be rather large for the amount of heat it can
remove from the airflow passing through the coil. Further, the
larger the evaporator coil becomes, the more refrigerant used in
the refrigeration system, thus effectively increasing potential
damage to the environment by an accidental atmospheric release.
[0003] Another form of heat exchangers is the microchannel coil.
Currently, the only major application of microchannel coils is in
the automotive industry. In an example automotive application,
microchannel coils may be used as a condenser and/or an evaporator
in the air conditioning system of an automobile. A microchannel
evaporator coil, for example, in an automotive air conditioning
system is typically located in a housing having multiple air ducts
leading to different locations in the passenger compartment of the
automobile. The housing containing the microchannel evaporator coil
is typically positioned behind the dashboard of the automobile,
where space to mount the housing is limited. Therefore, the
microchannel evaporator coil, which is much smaller than a
conventional fin-and-tube evaporator coil that would otherwise be
used in the automotive air conditioning system, is a suitable fit
for use in an automobile. Prior to the present invention, the
microchannel evaporator coil has not been used in large-scale
refrigeration systems, in part, because of the high costs and
difficulty that would be associated with manufacturing a
microchannel evaporator coil large enough to accommodate the
required refrigeration capacity of the large-scale refrigeration
system.
SUMMARY OF THE INVENTION
[0004] The present invention provides, in one aspect, a unit cooler
adapted for use in a refrigerated environment. The unit cooler
includes a housing adapted to be positioned within the refrigerated
environment and at least one microchannel evaporator coil supported
by the housing. The at least one microchannel evaporator coil
includes an inlet manifold and an outlet manifold. The inlet
manifold has an inlet port for receiving refrigerant, and the
outlet manifold has an outlet port for discharging the
refrigerant.
[0005] The present invention provides, in another aspect, a unit
cooler adapted for use in a refrigerated environment. The unit
cooler includes a housing adapted to be positioned within the
refrigerated environment, a first microchannel evaporator coil
supported by the housing and configured such that the refrigerant
makes at least one pass therethrough, and a second microchannel
evaporator coil supported by the housing and fluidly coupled with
the first microchannel evaporator coil. The second microchannel
evaporator coil is configured such that the refrigerant makes at
least one pass through the second microchannel evaporator coil
after making at least one pass through the first microchannel
evaporator coil.
[0006] The present invention provides, in yet another aspect, a
unit cooler adapted for use in a refrigerated environment. The unit
cooler includes a housing adapted to be positioned within the
refrigerated environment, a first microchannel evaporator coil
supported by the housing and configured such that refrigerant makes
at least one pass therethrough, a second microchannel evaporator
coil supported by the housing and configured such that the
refrigerant makes at least one pass therethrough, and a distributor
fluidly coupled with the first and second microchannel evaporator
coils. The distributor is configured to deliver the refrigerant to
the first and second microchannel evaporator coils. The unit cooler
also includes an outlet header fluidly coupled with the first and
second microchannel evaporator coils. The outlet header is
configured to receive refrigerant from the first and second
microchannel evaporator coils.
[0007] The present invention provides, in a further aspect, a
method of assembling a unit cooler adapted for use in a
refrigerated environment. The method includes providing a first
microchannel evaporator coil configured such that refrigerant makes
at least one pass therethrough, fluidly connecting the first
microchannel evaporator coil to a second microchannel evaporator
coil configured such that the refrigerant makes at least one pass
through the second microchannel evaporator coil after making at
least one pass through the first microchannel evaporator coil, and
substantially enclosing the first and second microchannel
evaporator coils in a housing.
[0008] The present invention provides, in another aspect, a method
of assembling a unit cooler adapted for use in a refrigerated
environment. The method includes providing a first microchannel
evaporator coil configured such that refrigerant makes at least one
pass therethrough, providing a second microchannel evaporator coil
configured such that the refrigerant makes at least one pass
therethrough, and fluidly connecting a distributor to the first and
second microchannel evaporator coils. The distributor is configured
to deliver the refrigerant to the first and second microchannel
evaporator coils. The method also includes fluidly connecting an
outlet header to the first and second microchannel evaporator
coils. The outlet header is configured to receive the refrigerant
from the first and second microchannel evaporator coils. The method
further includes substantially enclosing the first and second
microchannel evaporator coils in a housing.
[0009] Other features and aspects of the present invention will
become apparent to those skilled in the art upon review of the
following detailed description, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the drawings, wherein like reference numerals indicate
like parts:
[0011] FIG. 1 is an exploded perspective view of a unit cooler
including a first construction of an evaporator assembly of the
present invention.
[0012] FIG. 2 is an enlarged, perspective view of a first
microchannel evaporator coil of the evaporator assembly of FIG.
1.
[0013] FIG. 3a is a partial section view of the first microchannel
evaporator coil of FIG. 2, exposing multiple microchannels.
[0014] FIG. 3b is a broken view of the first microchannel
evaporator coil of FIG. 2.
[0015] FIG. 4 is an exploded perspective view of a unit cooler
including a second construction of an evaporator assembly of the
present invention.
[0016] FIG. 5a is a perspective view of a second microchannel
evaporator coil that may be utilized in an evaporator assembly of
the present invention.
[0017] FIG. 5b is a perspective view of a third microchannel
evaporator coil that may be utilized in an evaporator assembly of
the present invention.
[0018] FIG. 6a is a schematic view of multiple microchannel
evaporator coils arranged as a multiple row assembly, illustrating
the multiple coils in a series arrangement.
[0019] FIG. 6b is a schematic view of multiple microchannel
evaporator coils arranged as a multiple row assembly, illustrating
the multiple coils in a parallel arrangement.
[0020] FIG. 7a is a schematic view of multiple microchannel
evaporator coils arranged in a single row assembly, illustrating
the multiple coils in a series arrangement.
[0021] FIG. 7b is a schematic view of multiple microchannel
evaporator coils arranged in a single row assembly, illustrating
the multiple coils in a parallel arrangement.
[0022] FIG. 8a is a schematic view of multiple coil assemblies in a
series configuration with a distributor and an outlet header.
[0023] FIG. 8b is a schematic view of multiple coil assemblies in a
parallel configuration with a distributor and an outlet header.
[0024] FIG. 9 is a perspective view of a third construction of an
evaporator assembly of the present invention.
[0025] FIG. 10 is a perspective view of a fourth construction of an
evaporator assembly of the present invention.
[0026] FIG. 11 is a perspective view of a fifth construction of an
evaporator assembly of the present invention.
[0027] Before any features of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangements
of the components set forth in the following description or
illustrated in the drawings. The invention is capable of other
embodiments and of being practiced or being carried out in various
ways. Also, it is understood that the phraseology and terminology
used herein is for the purpose of description and should not be
regarded as limiting. The use of "including", "having", and
"comprising" and variations thereof herein is meant to encompass
the items listed thereafter and equivalents thereof as well as
additional items. The use of letters to identify elements of a
method or process is simply for identification and is not meant to
indicate that the elements should be performed in a particular
order.
DETAILED DESCRIPTION
[0028] With reference to FIG. 1, a unit cooler 5 including a first
configuration of an evaporator assembly 10 is shown. The unit
cooler 5 may be used in a large-scale refrigeration system or a
large-scale refrigerated environment, such as a walk-in cooler and
a refrigerated warehouse, for example. The evaporator assembly 10
in the unit cooler 5 may therefore recirculate the air in the
refrigerated environment to provide a refrigerated airflow to
products stored in the walk-in cooler or refrigerated
warehouse.
[0029] In a two-phase refrigeration system, the role of the
evaporator assembly 10 is to receive low-pressure liquid
refrigerant, remove heat from an airflow passing through the
evaporator assembly 10, and discharge gaseous refrigerant to one or
more compressors (not shown) remotely located from the evaporator
assembly 10. The low-pressure liquid refrigerant evaporates as it
passes through the evaporator assembly 10, such that the
refrigerant passes through a substantial portion of the evaporator
assembly 10 as a two-phase mixture (i.e., a liquid-gas state).
[0030] Gaseous refrigerant exiting the evaporator assembly 10 is
drawn into the one or more compressors for re-processing into the
refrigeration system. The one or more compressors pressurize the
gaseous refrigerant and pump the high-pressure, gaseous refrigerant
through one or more condensers (not shown), where heat transfer
between the high-pressure gaseous refrigerant and an airflow
passing through the one or more condensers causes the gaseous
refrigerant to condense. In a large-scale refrigeration system, one
or more condensers (not shown) may be positioned outside the
walk-in cooler or refrigerated warehouse, such as on the rooftop of
the buildings associated with the walk-in cooler and refrigerated
warehouse to allow heat transfer from the condensers to the outside
environment. High-pressure, liquid refrigerant exits the one or
more condensers and is routed back toward the evaporator assembly
10. Before entering the evaporator assembly 10, the refrigerant
passes through an expansion valve (not shown), which decreases the
pressure of the liquid refrigerant for intake by the evaporator
assembly 10. "Refrigerant-22," or "R-22," in addition to anyhydrous
ammonia, for example, may be used in such a refrigeration system to
provide sufficient cooling to the refrigeration system. If R-22 is
used as the refrigerant of choice, the components of the
refrigeration system in contact with the R-22 may be made from
copper, aluminum, or steel, among other materials. However, as
understood by those skilled in the art, if anyhydrous ammonia is
used as the refrigerant of choice, copper components of the
refrigeration system in contact with the anyhydrous ammonia may
corrode. Alternatively, other refrigerants (including both
two-phase and single-phase refrigerants or coolants) may be used
with the evaporator assembly 10. When used with a single-phase
refrigerant or coolant, the evaporator assembly 10 may be more
properly referred to as a heat exchanger assembly since the
single-phase refrigerant or coolant will not evaporate. However,
for convenience sake, the heat exchanger assembly will be referred
to as an evaporator assembly 10 throughout the application and
should be understood to also encompass heat exchanger assemblies of
a single-phase refrigeration or cooling system.
[0031] In the illustrated construction of FIG. 1, the unit cooler 5
includes a housing 7 to support the evaporator assembly 10, which
includes two microchannel evaporator coils 14a, 14b. The housing 7
includes an inlet 8 for drawing air from the refrigerated
environment into the housing 7, and an outlet 9 for discharging
refrigerated air from the housing 7 back to the refrigerated
environment. The housing 7 may be positioned in the walk-in cooler
or refrigerated warehouse at any of a number of different
elevations, and may further be suspended from the ceiling of the
walk-in cooler or refrigerated warehouse. The housing 7 may be a
substantially rectangular sheet metal structure as shown in FIG. 1.
However, the housing 7 may be made from any of a number of
different materials and comprise any number of different designs
other than that shown in FIG. 1. As such, the illustrated housing 7
of FIG. 1 is intended for illustrative purposes only.
[0032] As shown in FIGS. 3a and 3b, each microchannel evaporator
coil 14a, 14b includes an inlet manifold 22a, 22b and an outlet
manifold 26a, 26b fluidly connected by a plurality of flat tubes
30. The inlet manifold 22a, 22b includes an inlet port 34a, 34b for
receiving refrigerant, and the outlet manifold 26a, 26b includes an
outlet port 38a, 38b for discharging the refrigerant. One or more
baffles (not shown) may be placed in the inlet manifold 22a, 22b
and/or the outlet manifold 26a, 26b to cause the refrigerant to
make multiple passes through the flat tubes 30 for enhanced heat
transfer between the refrigerant and the airflow passing through
the coils 14a, 14b.
[0033] The flat tubes 30 may be formed to include multiple internal
passageways, or microchannels 42, that are much smaller in size
than the internal passageway of the coil in a conventional
fin-and-tube evaporator coil. The microchannels 42 allow for more
efficient heat transfer between the airflow passing over the flat
tubes 30 and the refrigerant carried within the microchannels 42,
compared to the airflow passing over the coil of the conventional
fin-and-tube evaporator coil. In the illustrated construction, the
microchannels 42 each are configured with a rectangular
cross-section, although other constructions of the flat tubes 30
may have passageways of other cross-sections. The flat tubes 30 are
separated into about 10 to 15 microchannels 42, with each
microchannel 42 being about 1.5 mm in height and about 1.5 mm in
width, compared to a diameter of about 9.5 mm (3/8'') to 12.7 mm
(1/2'') for the internal passageway of a coil in a conventional
fin-and-tube evaporator coil. However, in other constructions of
the flat tubes 30, the microchannels 42 may be as small as 0.5 mm
by 0.5 mm, or as large as 4 mm by 4 mm.
[0034] The flat tubes 30 may also be made from extruded aluminum to
enhance the heat transfer capabilities of the flat tubes 30. In the
illustrated construction, the flat tubes 30 are about 22 mm wide.
However, in other constructions, the flat tubes 30 may be as wide
as 26 mm, or as narrow as 18 mm. Further, the spacing between
adjacent flat tubes 30 may be about 9.5 mm. However, in other
constructions, the spacing between adjacent flat tubes 30 may be as
much as 16 mm, or as little as 3 mm.
[0035] As shown in FIG. 3b, each microchannel evaporator coil 14a,
14b includes a plurality of fins 46 coupled to and positioned along
the flat tubes 30. The fins 46 are generally arranged in a zig-zag
pattern between adjacent flat tubes 30. In the illustrated
construction, the fin density measured along the length of the flat
tubes 30 is between 12 and 24 fins per inch. However, in other
constructions of the microchannel evaporator coils 14a, 14b, the
fin density may be slightly less than 12 fins per inch or more than
24 fins per inch. Generally, the fins 46 aid in the heat transfer
between the airflow passing through the microchannel evaporator
coils 14a, 14b and the refrigerant carried by the microchannels 42.
The fins 46 may also include a plurality of louvers formed therein
to provide additional heat transfer area. The increased efficiency
of the microchannel evaporator coils 14a, 14b is due in part to
such a high fin density, compared to the fin density of 2 to 4 fins
per inch of a conventional fin-and-tube evaporator coil.
[0036] The increased efficiency of the microchannel evaporator
coils 14a, 14b, compared to a conventional fin-and-tube evaporator
coil, allows the microchannel evaporator coils 14a, 14b to be
physically much smaller than the fin-and-tube evaporator coil. As a
result, the microchannel evaporator coils 14a, 14b are not nearly
as tall, and are not nearly as wide as a conventional fin-and-tube
evaporator coil.
[0037] The microchannel evaporator coils 14a, 14b are attractive
for use with large-scale refrigeration systems for these and other
reasons. Since the microchannel evaporator coils 14a, 14b are much
smaller than conventional fin-and-tube evaporator coils, the
microchannel evaporator coils 14a, 14b may occupy less space in the
walk-in coolers or refrigerated warehouses in which they are
installed.
[0038] Since the microchannel evaporator coils 14a, 14b are much
smaller than conventional fin-and-tube evaporator coils, the
microchannel evaporator coils 14a, 14b may also contain less
refrigerant compared to the conventional fin-and-tube evaporator
coils. Further, less refrigerant may be required to be contained
within the entire refrigeration system, therefore effectively
decreasing potential damage to the environment by an accidental
atmospheric release. Also, as a result of being able to decrease
the amount of refrigerant in the refrigeration system, the
buildings associated with the walk-in cooler or refrigerated
warehouse may see an energy savings, since the compressor(s) may
expend less energy to compress the decreased amount of refrigerant
in the refrigeration system.
[0039] The evaporator assembly 10 also includes fans 50 coupled to
the microchannel evaporator coils 14a, 14b to provide an airflow
through the coils 14a, 14b. As shown in FIGS. 1b and 2, each
microchannel evaporator coil 14a, 14b includes two fans 50 mounted
thereon. Alternatively, centrifugal blowers (not shown) may be used
in place of the fans 50 or in combination with the fans 50. The
fans 50 are supported in a fan shroud 54, which guides the airflow
generated by the fans 50 through the microchannel evaporator coils
14a, 14b, and helps distribute the airflow amongst the face of each
evaporator coil 14a, 14b. In a preferred construction of the
evaporator assembly 10, the fans 50 may be "low-noise" fans, like
the SWEPTWING.TM. fans available from Revcor, Inc. of
Carpentersville, Ill. to help decrease noise emissions from the
evaporator assembly 10. In other constructions of the evaporator
assembly 10, more or less than two fans 50 may be used for each
evaporator coil 14a, 14b to generate the airflow through the
evaporator coil 14a, 14b. Also, the fans 50 and/or the shroud 54
may comprise any number of designs different than that shown in
FIGS. 1 and 2.
[0040] FIG. 2 illustrates the shroud 54 supporting an electric
motor 58 for driving one of the fans 50. The electric motor 58 may
be configured to operate using either an AC or DC power source.
Further, the electric motor 58 may be electrically connected to a
controller (not shown) that selectively activates the electric
motor 58 to drive the fan 50 depending on any number of conditions
monitored by the controller. For example, the fans 50 may be cycled
on and off to either increase or decrease the heat transfer
capability of the evaporator coils 14a, 14b.
[0041] FIG. 1 illustrates two microchannel evaporator coils 14a,
14b fluidly connected with the refrigeration system in a series
arrangement. The inlet port 34a of a first microchannel evaporator
coil 14a is shown coupled to an inlet header 59, whereby
low-pressure, liquid refrigerant is pumped to the first
microchannel evaporator coil 14a via the inlet header 59. In the
illustrated construction, the inlet header 59 is coupled to the
inlet port 34a by a brazing or welding process. Such a brazing or
welding process provides a substantially fluid-tight connection
between the inlet header 59 and the inlet port 34a. However, other
constructions of the evaporator assembly 10 may utilize some sort
of fluid-tight releasable couplings to allow serviceability of the
coils 14a, 14b.
[0042] The outlet port 38a of the first microchannel evaporator
coil 14a is shown coupled to an inlet port 34b of a second
microchannel evaporator coil 14b via a connecting conduit 60. In
the illustrated construction, the outlet port 38a of the first
microchannel evaporator coil 14a is coupled to the connecting
conduit 60 by a brazing or welding process, and the inlet port 34b
of the second microchannel evaporator coil 14b is also coupled the
connecting conduit 60 by a brazing or welding process. As
previously stated, such a brazing or welding process provides a
substantially fluid-tight connection between the outlet port 38a of
the first microchannel evaporator coil 14a and the inlet port 34b
of the second microchannel evaporator coil 14b. However, other
constructions of the evaporator assembly 10 may utilize some sort
of permanent or releasable fluid-tight couplings.
[0043] The outlet port 38b of the second microchannel evaporator
coil 14b is shown coupled to an outlet header 61, whereby
substantially gaseous refrigerant is discharged from the second
microchannel evaporator coil 14b to the outlet header 61 for
transport to the compressor in the refrigeration system. Further,
in the illustrated construction, the outlet port 38b of the second
microchannel evaporator coil 14b is coupled to the outlet header 61
by a brazing or welding process to provide a substantially
fluid-tight connection between the outlet port 38b of the second
microchannel evaporator coil 14b and the outlet header 61. However,
other constructions of the evaporator assembly 10 may utilize some
sort of permanent or releasable fluid-tight couplings.
[0044] During operation of the refrigeration system utilizing the
evaporator assembly 10 of FIG. 1, the fans 50 may be activated to
provide an airflow through the first microchannel evaporator coil
14a. Low-pressure, liquid refrigerant is pumped into the first
microchannel evaporator coil 14a, where the heat transfer between
the airflow passing through the evaporator coil 14a and the
refrigerant causes the liquid refrigerant to at least partially
evaporate as the refrigerant passes through the flat tubes 30. If
baffles are not placed in either of the inlet or outlet manifolds
22a, 26a of the first microchannel evaporator coil 14a, the
refrigerant will make one pass from the inlet manifold 22a to the
outlet manifold 26a before being discharged from the first
microchannel evaporator coil 14a.
[0045] Since the evaporator coils 14a, 14b are connected in a
series arrangement, the refrigerant is passed from the first
microchannel evaporator coil 14a to the second microchannel
evaporator coil 14b. If only a portion of the low-pressure, liquid
refrigerant is evaporated in the first microchannel evaporator coil
14a, then the remaining portion is evaporated in the second
microchannel evaporator coil 14b. Like the first microchannel
evaporator coil 14a, if baffles are not placed in either of the
inlet or outlet manifolds 22b, 26b of the second microchannel
evaporator coil 14b, the refrigerant will make one pass from the
inlet manifold 22b to the outlet manifold 26b before being
discharged from the second microchannel evaporator coil 14b.
Further, the fans 50 may be activated to provide the airflow
through the second microchannel evaporator coil 14b.
[0046] FIG. 4 illustrates a unit cooler 63 including the housing 7
to support an evaporator assembly 62, which includes two
microchannel evaporator coils 64a, 64b fluidly connected with the
refrigeration system in a parallel arrangement. The housing 7
illustrated in FIG. 4 is substantially the same as that shown in
FIG. 1, the particular design of which is for illustrative purposes
only and will not be further discussed. The fans 50 and the fan
shrouds 54 are also substantially the same as those shown in FIG.
1, and will not be further discussed. Inlet ports 66a, 66b of the
first and second microchannel evaporator coils 64a, 64b are shown
extending from inlet manifolds 70a, 70b and coupled to respective
inlet headers 74a, 74b, whereby low-pressure, liquid refrigerant is
pumped to the first and second microchannel evaporator coils 64a,
64b via the inlet headers 74a, 74b. In the illustrated
construction, the inlet headers 74a, 74b are coupled to the inlet
ports 66a, 66b of the first and second microchannel evaporator
coils 64a, 64b by a brazing or welding process to provide a
substantially fluid-tight connection between the inlet headers 74a,
74b and the inlet ports 66a, 66b. However, other constructions of
the evaporator assembly 62 may utilize some sort of permanent or
releasable fluid-tight couplings.
[0047] With continued reference to FIG. 4, a distributor 65 may be
used with the evaporator assembly 62 to facilitate a substantially
equal distribution of refrigerant to the coils 64a, 64b. A single
inlet conduit 71 may fluidly connect the distributor 65 with the
one or more condensers, or the single inlet conduit 71 may fluidly
connect the distributor 65 with a liquid receiver storing
compressed, liquid refrigerant. The inlet headers 74a, 74b fluidly
connect to the distributor 65 to receive substantially equal
portions of refrigerant.
[0048] One or more expansion valves may be used with the evaporator
assembly 62 to decrease the pressure of the liquid refrigerant in
the refrigeration system before the liquid refrigerant enters the
evaporator assembly 62, as discussed above. With reference to FIG.
4, a single expansion valve may be positioned between the
condensers/liquid receiver and the distributor 65, such that both
of the coils 64a, 64b receive refrigerant at the same pressure.
Alternatively, an expansion valve may be associated with each inlet
header 74a, 74b, such that the coils 64a, 64b may receive
refrigerant at different pressures.
[0049] Outlet ports 78a, 78b of the first and second microchannel
evaporator coils 64a, 64b are shown extending from outlet manifolds
82a, 82b coupled to an outlet header 86, whereby substantially
gaseous refrigerant is discharged from the first and second
microchannel evaporator coils 64a, 64b via the outlet header 86. In
the illustrated construction, the outlet header 86 is coupled to
the outlet ports 78a, 78b of the first and second microchannel
evaporator coils 64a, 64b by a brazing or welding process to
provide a substantially fluid-tight connection between the outlet
header 86 and the outlet ports 78a, 78b. However, other
constructions of the evaporator assembly 62 may utilize some sort
of permanent or releasable fluid-tight couplings.
[0050] In the illustrated construction, the inlet ports 66a, 66b
extend substantially transversely from the inlet manifolds 70a, 70b
to fluidly connect with the inlet headers 74a, 74b, and the outlet
ports 78a, 78b extend substantially transversely from the outlet
manifolds 82a, 82b to fluidly connect with the outlet header 86.
However, in other constructions of the evaporator assembly 62, the
inlet ports 66a, 66b and the outlet ports 78a, 78b may extend from
the respective inlet manifolds 70a, 70b and the outlet manifolds
82a, 82b as shown in FIG. 1, and utilize additional intermediate
piping to fluidly connect the inlet ports 66a, 66b with the inlet
headers 74a, 74b and the outlet ports 78a, 78b with the outlet
header 86.
[0051] During operation of the refrigeration system utilizing the
evaporator assembly 62 of FIG. 4, the fans 50 may be activated to
provide the airflow through the coils 64a, 64b, while the
low-pressure, liquid refrigerant is pumped through the single inlet
conduit 71 to the distributor 65, where substantially equal
portions of the liquid refrigerant enter the first microchannel
condenser coil 64a and the second microchannel condenser coil 64b.
Heat transfer between the airflow passing through the evaporator
coils 64a, 64b and the refrigerant causes the liquid refrigerant to
evaporate as the refrigerant passes through the flat tubes 30. If
baffles are not placed in either of the inlet manifold 70a or the
outlet manifold 82a of the first microchannel evaporator coil 64a,
the refrigerant will make one pass from the inlet manifold 70a to
the outlet manifold 82a before being discharged from the first
microchannel evaporator coil 64a to the outlet header 86.
[0052] Since the evaporator coils 64a, 64b are connected with the
refrigeration system in a parallel arrangement, and if baffles are
not placed in either of the inlet manifold 70b or the outlet
manifold 82b of the second microchannel evaporator coil 64b, the
refrigerant will make one pass from the inlet manifold 70b to the
outlet manifold 82b before being discharged from the second
microchannel evaporator coil 64b to the outlet header 86, where the
substantially gaseous refrigerant rejoins the substantially gaseous
refrigerant discharged by the first microchannel evaporator coil
64a.
[0053] Each microchannel evaporator coil 64a, 64b may also include
multiple inlet and outlet ports (not shown), corresponding with
multiple baffles (not shown) located within the inlet manifolds
70a, 70b and/or the outlet manifolds 82a, 82b to provide multiple
refrigeration circuits throughout each microchannel evaporator coil
64a, 64b.
[0054] The microchannel evaporator coils 14a, 14b, 64a, 64b allow
for a unique method of assembling the evaporator assemblies 10, 62.
As previously stated, a single, large conventional fin-and-tube
evaporator coil is typically provided in refrigeration systems for
large-scale refrigerated environments. This conventional
fin-and-tube evaporator coil must be appropriately sized to provide
the refrigeration capacity desired in the refrigerated environment.
Such an evaporator coil must often be custom manufactured to the
size required by the refrigeration system. Further, the housing 7
and fan shrouds may also require custom manufacturing to match up
with the custom manufactured conventional fin and tube evaporator
coil. This may drive up the costs associated with manufacturing an
evaporator assembly utilizing a conventional fin-and-tube
evaporator coil.
[0055] The microchannel evaporator coils 14a, 14b, 64a, 64b are
manufactured in standard sizes, which allows the manufacturer of
the evaporator assembly 10 or 62 to utilize their expertise to
calculate the total refrigeration capacity of a particular
refrigeration system and determine how many standard-sized
microchannel evaporator coils 14a, 14b or 64a, 64b will be required
to satisfy the total refrigeration capacity of the refrigeration
system. After determining how many standard-sized microchannel
evaporator coils 14a, 14b or 64a, 64b will be required, the
manufacturer may utilize their capabilities to put together the
evaporator assembly 10 or 62. Fluid connections may be made by
brazing or welding processes, or releasable couplings may be used
to allow serviceability of the coils 14a, 14b or 64a, 64b. Further,
the fans 50 and the fan shrouds 54 may be manufactured or purchased
by the evaporator assembly manufacturer in standard sizes to match
up with the standard-sized microchannel evaporator coils 14a, 14b,
64a, 64b. Also, the housing 7 may be either custom made to support
multiple connected microchannel evaporator coils 14a, 14b or 64a,
64b, or the housing 7 may be standard-sized to support a single or
dual microchannel evaporator coils 14a, 14b or 64a, 64b, for
example. This method of assembling the evaporator assemblies 10, 62
may allow the manufacturer to streamline their operation, which in
turn may result in decreased costs for the manufacturer.
[0056] Although only two microchannel evaporator coils 14a, 14b or
64a, 64b are shown in the illustrated constructions of FIGS. 1 and
4, more or less than two microchannel evaporator coils 14a, 14b or
64a, 64b may be included in the evaporator assemblies 10 or 62 to
satisfy the total refrigeration capacity of the refrigeration
system in which the microchannel evaporator coils 14a, 14b or 64a,
64b will be used.
[0057] With reference to FIGS. 5a and 5b, other evaporator coils
may be utilized in the evaporator assemblies 10, 62. FIG. 5a
illustrates a microchannel evaporator coil 98 substantially similar
to the coils 14a, 14b, 64a, 64b with the exception that the coil 98
includes multiple inlet ports 102 and outlet ports 106. This style
of microchannel evaporator coil 98 may provide a better
distribution of low-pressure, liquid refrigerant to an inlet
manifold 110 of the coil 98, in addition to a better distribution
of gaseous refrigerant from an outlet manifold 114 of the coil
98.
[0058] FIG. 5b illustrates another microchannel evaporator coil 118
substantially similar to the coils 14a, 14b, 64a, 64b, 98 with the
exception that the coil 118 is divided into two separate and
distinct fluid circuits by a baffle 122 positioned in an inlet
manifold 126 of the coil 118 and another baffle 130 positioned in
an outlet manifold 134 of the coil 118. This style of microchannel
evaporator coil 118 may allow refrigerant from multiple
refrigeration circuits to be passed through the coil 118.
[0059] With reference to FIGS. 6a-7b, any of the microchannel
evaporator coils 14a, 14b, 64a, 64b, 98, or 118 may be grouped
together in either single-row assemblies or multiple-row
assemblies. FIGS. 6a and 6b illustrate coils being grouped in
multiple-row assemblies 138, 142, respectively. Specifically, FIGS.
6a and 6b illustrate coils being grouped in three-row assemblies
138, 142. In the three-row assemblies 138, 142 of FIGS. 6a and 6b,
the coils are stacked one on top of another such that airflow is
directed through all of the coils. Although three coils are shown
in the multiple-row assemblies 138, 142 of FIGS. 6a and 6b, more or
less than three coils 14a, 14b, 64a, 64b, 98, or 118 may be used
depending on the total refrigeration capacity of a particular
refrigeration system in which the assemblies 138, 142 are used. In
addition, although FIGS. 6a and 6b generally illustrate the coils
14a, 14b, it should be known that any of the coils 14a, 14b, 64a,
64b, 98, or 118 may be used in forming the assemblies 138, 142.
[0060] With particular reference to FIG. 6a, the three coils in the
assembly 138 are shown in a fluid series connection, whereby
refrigerant is passed through the three coils one after another.
However, with particular reference to FIG. 6b, the three coils in
the assembly 142 are shown in a fluid parallel connection, whereby
refrigerant is passed through the coils independently of one
another. In constructing the evaporator assemblies 10, 62, it is up
to the manufacturer to determine if multiple-row assemblies 138,
142 will be used. Furthermore, if multiple-row assemblies 138, 142
are to be used, it is up to the manufacturer to determine whether
to use an assembly 138 having coils grouped in a fluid series
connection, or an assembly 142 having coils grouped in a fluid
parallel connection.
[0061] FIGS. 7a and 7b illustrate coils being grouped in single-row
assemblies 146, 150. Specifically, FIGS. 7a and 7b illustrate the
coils being grouped in a single-row assembly 146 of three coils. In
the single-row assemblies 146, 150 of FIGS. 7a and 7b, the coils
are unfolded, or spread out such that airflow passing through one
of the coils is not directed through another of the three coils.
Although three coils are shown in the single-row assemblies 146,
150 of FIGS. 7a and 7b, more or less than three coils may be used
depending on the total refrigeration capacity of the particular
refrigeration system in which the assemblies 146, 150 are used. In
addition, although FIGS. 7a and 7b generally illustrate the coils
14a, 14b, it should be known that any of the coils 14a, 14b, 64a,
64b, 98, or 118 may be used in forming the assemblies 146, 150.
[0062] With particular reference to FIG. 7a, the three coils in the
assembly 146 are shown in a fluid series connection, whereby
refrigerant is passed through the three coils one after another.
However, with particular reference to FIG. 7b, the three coils in
the assembly 150 are shown in a fluid parallel connection, whereby
refrigerant is passed through the coils independently of one
another. In constructing the evaporator assemblies 10, 62, it is up
to the manufacturer to determine if single-row assemblies 146, 150
will be used. Furthermore, if single-row assemblies 146, 150 are to
be used, it is up to the manufacturer to determine whether to use
an assembly 146 having coils grouped in a fluid series connection,
or an assembly 150 having coils grouped in a fluid parallel
connection.
[0063] With reference to FIGS. 8a and 8b, one or more assemblies
138, 142, 146, or 150 may be grouped into a series configuration
154 or a parallel configuration 158. As shown in FIG. 8a, a
three-row assembly 138 and a single row assembly 146 are grouped
into a fluid series configuration 154 between an inlet header 162
and an outlet header 166. The distributor 65 receives low-pressure,
liquid refrigerant from one or more condensers or a liquid receiver
via the single inlet conduit 71, and the inlet header 162 fluidly
connects the distributor 65 and the three-row assembly 138. An
expansion valve (not shown) may also be used to reduce the pressure
of the liquid refrigerant as described above. Although the
three-row assembly 138 and single-row assembly 146 are shown in the
series configuration 154 of FIG. 8a, any combination of
multiple-row assemblies 138 or 142 and single-row assemblies 146 or
150 may be used depending on the determination of the manufacturer.
In addition, more or less than two assemblies 138, 142, 146, or 150
may be used in the series configuration 154 depending on the total
refrigeration capacity of the particular refrigeration system in
which the series configuration 154 is used. In addition, although
FIG. 8a generally illustrates the coils 14a, 14b, it should be
known that any of the coils 14a, 14b, 64a, 64b, 98, or 118 may be
used in forming the assemblies 138, 142, 146, or 150 that comprise
either the series configuration 154 or the parallel configuration
158.
[0064] As shown in FIG. 8b, a three-row assembly 138 and a single
row assembly 146 are grouped into a fluid parallel configuration
158. The distributor 65 receives low-pressure, liquid refrigerant
from one or more condensers or a liquid receiver via the single
inlet conduit 71, and a first inlet header 162 fluidly connects the
distributor 65 and the three-row assembly 138, and a second inlet
header 162 fluidly connects the distributor 65 and the single-row
assembly 146. An expansion valve (not shown) may also be used to
reduce the pressure of the liquid refrigerant as described above.
Although the three-row assembly 138 and the single-row assembly 146
are shown in the parallel configuration 158 of FIG. 8b, any
combination of multiple-row assemblies 138 or 142 and single-row
assemblies 146 or 150 may be used depending on the determination of
the manufacturer. In addition, more or less than two assemblies
138, 142, 146, or 150 may be used in the parallel configuration 158
depending on the total refrigeration capacity of the particular
refrigeration system in which the parallel configuration 158 is
used. In addition, although FIG. 8b generally illustrates the coils
14a, 14b, it should be known that any of the coils 14a, 14b, 64a,
64b, 98, or 118 may be used in forming the assemblies 138, 142,
146, or 150 that comprise either the series configuration 154 or
the parallel configuration 158.
[0065] Using the above terminology, FIG. 1 illustrates a single-row
assembly 146 in a series configuration 154 between the inlet header
59 and the outlet header 61, whereby the coils 14a, 14b in the
single-row assembly 146 are grouped into a fluid series connection.
Also, using the above terminology, FIG. 4 illustrates a single-row
assembly 150 in a parallel configuration 158 between the inlet
headers 74a, 74b and the outlet header 86, whereby the coils 64a,
64b in the single-row assembly 150 are grouped into a fluid
parallel connection.
[0066] FIG. 9 illustrates a third construction of an evaporator
assembly 170 including three two-row assemblies 138 in a parallel
configuration 158 between inlet headers 174 and an outlet header
178. Each two-row assembly 138 includes two microchannel evaporator
coils 14a, 14b grouped in a fluid series connection. Rather than
being permanently connected to the inlet and outlet headers 174,
178, respectively, the coils 14a, 14b may be coupled to the inlet
and outlet headers 174, 178 by fluid-tight releasable couplings
182. The couplings 182 are illustrated in FIG. 9, and may comprise
any known suitable fluid-tight, quick-release coupling and/or
releasable coupling. By using the couplings 182 in place of
permanently connecting the coils 14a, 14b to the inlet and outlet
headers 174, 178, the assemblies 138 are permitted to be removed
and/or replaced to accommodate a varying refrigeration capacity or
to permit serviceability of a damaged assembly 138.
[0067] FIG. 10 illustrates a fourth construction of an evaporator
assembly 190 including a two-row assembly 138, with three separate
and distinct fluid circuits, in a parallel configuration 158
between multiple inlet headers 194 and multiple outlet headers 198.
The two-row assembly 138 includes two microchannel evaporator coils
118 grouped in a fluid series connection. As previously explained,
the coils 118 each include respective baffles 122, 130 in the inlet
and outlet manifolds 126, 134 to establish separate and distinct
fluid circuits through the assembly 138. Like the assemblies 138 of
FIG. 9, the assembly 138 of FIG. 10 may utilize fluid-tight
couplings 182 to permit removal and/or replacement of the assembly
138 to accommodate a varying refrigeration capacity or to permit
serviceability of a damaged assembly 138.
[0068] FIG. 11 illustrates a fifth construction of an evaporator
assembly 202 including a single-row assembly 150 between inlet
headers 206 and an outlet header 210. The single-row assembly 150
includes four microchannel evaporator coils 64a, 64b grouped in a
fluid parallel connection. The coils 64a, 64b are inclined with
respect to the inlet and outlet headers 206, 210, such that the
footprint of the evaporator assembly 202 is reduced (compared to
the assembly 62 of FIG. 4, for example). Although FIG. 11 generally
illustrates the coils 64a, 64b, it should be known that any of the
coils 14a, 14b, 64a, 64b, 98, or 118 may be used in forming the
assembly 150.
[0069] As indicated by FIGS. 1, 4, and 9-11, the evaporator
assemblies 10, 62, 170, 190, 202 can be relatively small or
relatively large. If a relatively large refrigeration capacity must
be satisfied, a relatively large evaporator assembly (such as the
assembly 170 of FIG. 9) having a plurality of assemblies 138, 142,
146, or 150 may be used. However, if a relatively small
refrigeration capacity must be satisfied, a relatively small
evaporator assembly (such as the assemblies 10, 62 of FIGS. 1 and
4, respectively) having only one assembly 138, 142, 146, 150 may be
used. The evaporator assemblies 10, 62, 170, 190, 202 are shown for
exemplary reasons only, and are not meant to limit the spirit
and/or scope of the present invention.
* * * * *