U.S. patent application number 11/908418 was filed with the patent office on 2008-08-07 for multi-part heat exchanger.
This patent application is currently assigned to CARRIER COMMERCIAL REFRIGERATION, INC.. Invention is credited to Yu Chen, Hans-Joachim Huff, Tobias H. Sienel, Parmesh Verma.
Application Number | 20080184731 11/908418 |
Document ID | / |
Family ID | 37024267 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080184731 |
Kind Code |
A1 |
Sienel; Tobias H. ; et
al. |
August 7, 2008 |
Multi-Part Heat Exchanger
Abstract
A refrigeration system includes a compressor for driving a
refrigerant along a flow path in at least a first mode of system
operation; a first heat exchanger along the flow path downstream of
the compressor in the first mode; a second heat exchanger along the
flow path upstream of the compressor in the first mode; and a
pressure regulator or expansion device in the flow path downstream
of the first heat exchanger and upstream of the second heat
exchanger in the first mode, wherein the first heat exchanger
comprises a plurality of heat exchanger components arranged along a
flow path of heat exchange fluid for the first heat exchanger. The
heat exchanger components can be positioned in smaller available
areas within the unit and thereby use space more efficiently.
Inventors: |
Sienel; Tobias H.; (East
Hampton, MA) ; Chen; Yu; (East Hartford, CT) ;
Verma; Parmesh; (Manchester, CT) ; Huff;
Hans-Joachim; (West Hartford, CT) |
Correspondence
Address: |
BACHMAN & LAPOINTE, P.C. (UTC)
900 CHAPEL STREET, SUITE 1201
NEW HAVEN
CT
06510-2802
US
|
Assignee: |
CARRIER COMMERCIAL REFRIGERATION,
INC.
Charlotte
NC
|
Family ID: |
37024267 |
Appl. No.: |
11/908418 |
Filed: |
December 30, 2005 |
PCT Filed: |
December 30, 2005 |
PCT NO: |
PCT/US2005/047524 |
371 Date: |
September 12, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60663917 |
Mar 18, 2005 |
|
|
|
Current U.S.
Class: |
62/467 |
Current CPC
Class: |
F25B 2309/061 20130101;
F25D 2500/02 20130101; F25B 9/008 20130101; F25D 2317/0651
20130101; F25B 6/04 20130101; F25D 19/02 20130101; F25D 23/003
20130101; F25D 2323/00271 20130101; F25D 2323/00264 20130101; F25D
2317/0661 20130101 |
Class at
Publication: |
62/467 |
International
Class: |
F25B 1/00 20060101
F25B001/00 |
Claims
1. A refrigeration system comprising: a compressor for driving a
refrigerant along a flow path in at least a first mode of system
operation; a first heat exchanger along the flow path downstream of
the compressor in the first mode; a second heat exchanger along the
flow path upstream of the compressor in the first mode; and an
expansion device in the flow path downstream of the first heat
exchanger and upstream of the second heat exchanger in the first
mode, wherein the first heat exchanger comprises a plurality of
heat exchanger components arranged along a flow path of heat
exchange fluid for the first heat exchanger.
2. The system of claim 1 wherein the flow path of the heat exchange
fluid is counter to the flow of refrigerant in the heat exchange
components.
3. The system of claim 1 wherein the second heat exchanger also
comprises a plurality of heat exchange components.
4. The system of claim 1 wherein the first heat exchanger is
mounted within a housing having separate and discrete available
spaces, and wherein the heat exchanger components are positioned in
the spaces.
5. The system of claim 1 further comprising a refrigerator housing
defining a cassette receiving area, and wherein the heat exchanger
components are mounted within a cassette adapted to be inserted
into the receiving area.
6. The system of claim 1, wherein the heat exchanger components
include at least a first component and a second component, and
wherein the first component has a different shape than the second
component.
7. The system of claim 1, wherein the first heat exchanger is
mounted within a housing defining a flow path for heat exchanger
medium to flow past the first heat exchanger, and wherein the flow
path has a cross sectional flow area and a decreased flow area zone
along the path, and wherein at least one of the components is
positioned at the decreased flow area zone.
8. The system of claim 1, wherein the refrigerant comprises, in
major mass part, CO.sub.2; and the first and second heat exchangers
are refrigerant-air heat exchangers.
9. The system of claim 1, wherein the system contains a refrigerant
and the refrigerant is a transcritical vapor compression.
10. A beverage cooling device comprising the system of claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of
earlier filed Provisional Application Ser. No. 60/663,917 filed
Mar. 18, 2005. Further, copending application docket 05-258-WO,
entitled HIGH SIDE PRESSURE REGULATION FOR TRANSCRITICAL VAPOR
COMPRESSION SYSTEM and filed on even date herewith, and the
aforesaid Provisional Application Ser. No. 60/663,917, disclose
prior art and inventive cooler systems. The disclosure of said
applications is incorporated by reference herein as if set forth at
length.
BACKGROUND OF THE INVENTION
[0002] The invention relates to vapor compression systems and, more
particularly, to a heat exchanger configuration for such a
system.
[0003] In many vapor compression systems, the heat exchanger
placement is very much constrained by space. For these
applications, the efficiency of the system is often low in
comparison to a system with a properly sized heat exchanger due to
the large temperature difference between the air and the
refrigerant in the heat exchangers.
[0004] The need exists for more efficient heat exchange despite
space requirements of the system, and it is an object of the
invention to provide such a system.
[0005] Other objects and advantages will appear herein below.
SUMMARY OF THE INVENTION
[0006] According to the present invention, the foregoing objects
and advantages have been attained.
[0007] According to the invention, a refrigeration system is
provided which includes a compressor for driving a refrigerant
along a flow path in at least a first mode of system operation; a
first heat exchanger along the flow path downstream of the
compressor in the first mode; a second heat exchanger along the
flow path upstream of the compressor in the first mode; and an
expansion device in the flow path downstream of the first heat
exchanger and upstream of the second heat exchanger in the first
mode, wherein the first heat exchanger comprises a plurality of
heat exchanger components arranged along a flow path of heat
exchange fluid for the first heat exchanger. The heat exchanger
components can be positioned in smaller available areas within the
unit and thereby use space more efficiently. Further, flow to these
heat exchange components can be routed so as to provide counter
flow of the heat exchange fluid, for example air, with the
refrigerant. In addition, the system of the present invention can
be at least partially if not entirely incorporated into a cassette
which can be readily interchanged within the existing housing or
case of a refrigerator unit to allow replacement of the cassette
when needed without replacing the entire unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A detailed description of preferred embodiments of the
invention follows with reference to the attached drawings,
wherein:
[0009] FIG. 1 is a perspective view of a system having a multi-part
heat exchanger according to the invention;
[0010] FIG. 2 is a schematic illustration of a multi-part heat
exchanger system according to the invention; and
[0011] FIG. 3 illustrates the refrigerant and air flow in a system
according to the invention.
DETAILED DESCRIPTION
[0012] The invention relates to a vapor compression system of a
refrigerator unit and, more particularly, to the arrangement of a
heat exchanger in a vapor compression system, preferably in a
transcritical vapor compression system.
[0013] As set forth above, the greater the area of heat exchanger
contact with heat exchange medium such as air, the greater the
efficiency in operation of a vapor compression system. In
accordance with the present invention, greater contact area between
the heat exchanger and heat exchange medium is obtained by
utilizing all potentially available spaces within a particular
vapor compression system to house additional components of a heat
exchanger, such that the heat exchanger is implemented in a series
or plurality of heat exchange components. In this manner, small
available spaces are nevertheless utilized to increase heat
exchange efficiency and, therefore, efficiency of the overall
system.
[0014] FIG. 1 shows a system in accordance with the present
invention. FIG. 1 shows system 10 which, in this particular
embodiment, is the vapor compression system for a bottle cooler
refrigeration assembly. FIG. 1 shows the lower portion of such an
assembly, including a housing 12 containing a vapor compression
system. Reference is made to FIGS. 1-3 for further discussion of
the vapor compression system, which includes a compressor 14, a
downstream heat exchanger 16, an expansion device 18 and an
evaporator 20. Compressor 14 is operative to drive a refrigerant
along refrigerant lines (FIG. 3) first to heat exchanger 16, then
to expansion device 18, and then to evaporator 20. Refrigerant
flows from evaporator 20 back to compressor 14 to complete the
circuit.
[0015] In accordance with the present invention, first heat
exchanger 16 is provided having a first heat exchange component 22
and a second heat exchange component 24. These components are
positioned within housing 12 to take advantage of the spaces
available such that high amounts of heat exchange can be
accomplished with relatively small available spaces.
[0016] As illustrated in the drawings, housing 12 defines a flow
path for heat exchange medium, for example air, to enter into heat
exchange relationship with first heat exchanger 16. An upper
portion of housing 12 also defines a flow path for air from within
the refrigerated space (not shown, but located above housing 12 and
supplied with air cooled by arrows 27) to be treated with second
heat exchanger 20.
[0017] In connection with any heat exchange system, and
particularly in connection with vapor compression systems which
form the preferred embodiment of the present invention, extended
area of heat exchange contact between the heat exchange medium and
the refrigerant-carrying heat exchangers is critical to obtaining
good efficiency of the system. It has also been found that such
systems operate most efficiently with counter-current flow of
refrigerant verses heat exchange medium. That is, referring to FIG.
3, if heat exchange medium or air is flowing in the direction of
arrows 26, it is preferred that refrigerant flow through heat
exchanger 16 be in the flow direction shown such that the direction
of flow of refrigerant is counter to that of the flow of heat
exchange medium. Referring further to FIGS. 1-3, it should readily
apparent that first and second components 22, 24 of first heat
exchanger 16 can and most likely will be different in size and/or
shape so that these components can advantageously take advantage of
the available space within a particular device. For example, in the
embodiment shown, first component 22 has a relatively larger area
in a transverse plane with respect to the flow, and is relatively
thin from front to back. This is because first component 22 in this
embodiment is sized to fit within a relatively narrow (from front
to back) space toward the open front of housing 12. A second space
within housing 12 in this embodiment is available beneath a wall 28
which separates one portion of housing 12 for treating the first
flow of air 26 from a second portion of housing 12 for treating the
second portion of air 27. This wall 28 extends downwardly relative
to the outer contour of housing 12, and results in a restriction in
flow area as air flows from the inlet end 30 to the outlet end 32
of housing 12. This zone of decreased cross sectional flow area
results in an increase in velocity of the air flowing through this
zone. An increased velocity flow has been found to provide improved
efficiency heat exchange in heat exchangers such as that of the
present invention. According to the invention, it is preferred to
position second component 24 of first heat exchanger 16 within this
zone of decreased cross sectional flow area so as to take advantage
of the increased flow of velocity in this zone. Further, the shape
of this zone dictates a different configuration for second
component 24 as compared to first component 22. Specifically, this
zone has a substantially short height and yet extends much further
from the inlet side toward the outlet side as compared to the space
for accommodating first component 22. Thus, second component 24 is
advantageously shaped and adapted to fit properly within this
space, thereby providing maximum possible heat exchange area and
further taking advantage of the increased flow velocity of air
through that zone.
[0018] As set forth above, one preferred implementation of the
vapor compression system in accordance with the present invention
is a transcritical vapor compression system. Such a system, as is
known to a person of skill in the art, operates upon a refrigerant
which does not condense in the first heat exchanger. One example of
a refrigerant of a transcritical vapor compression system is
CO.sub.2. Of course, other refrigerants could be used well within
the scope of the present invention to provide suitable vapor
compression systems which would benefit from the heat exchanger
arrangement of the present invention.
[0019] Expansion device 18 can be any suitable expansion device for
decreasing the pressure of refrigerant passing there through as is
known to a person of skill in the art. Various known expansion
devices could be utilized for this purpose. In accordance with a
preferred aspect of the present invention, a pressure regulator
such as that disclosed in a commonly-owned and simultaneously filed
PCT Patent Application bearing attorney docket number 05-258-WO and
having the title HIGH SIDE PRESSURE REGULATION FOR TRANSCRITICAL
VAPOR COMPRESSION-SYSTEM, is a particularly desirable type of
expansion device for use in connection with the present invention.
As used herein, the term expansion device is considered to include
such a pressure regulator.
[0020] Second heat exchanger 20, which performs the function of an
evaporator, is shown as a single heat exchanger in the drawings. It
should be appreciated that second heat exchanger 20 could also be
provided in a plurality of components, as well, in the event that
space for treatment of flow of air from the refrigerated space is
particularly small and/or irregularly shaped.
[0021] FIG. 3 shows refrigerant lines connecting from first heat
exchanger 16 to expansion device 18 and then to second heat
exchanger or evaporator 20. Refrigerant flows from evaporator 20
back to the suction inlet of compressor 14.
[0022] It should be appreciated that the present invention provides
for increased heat exchange efficiency due to increase in area of
contact between the heat exchanger and the heat exchange medium. It
should further be appreciated that the system of the present
invention provides for enhanced utilization of space available for
heat exchange, thereby providing more efficient operation of a
vapor compression system as desired in accordance with the present
invention.
[0023] In some systems it is possible to use a heat exchanger
divided into multiple parts and arranged where space is available
to increase the overall heat transfer area of the heat exchanger.
This disclosure makes use of this with the addition of arranging
the multiple parts of the heat exchanger in such a way that the
effective refrigerant flows and air (or other heat transfer
mediums) flows are opposite to each other.
[0024] FIG. 2 shows an example with a two part heat exchanger. In
this case the refrigerant flow would be circuited first through
component 24 and then through component 22 if the air flow was
directed from front to back. The refrigerant flow would be
circuited first through component 22 and then through component 24
if the air flow was from back to front. This concept is especially
useful for transcritical vapor compression systems (such as using
CO.sub.2), where it is critically important for efficiency that the
temperature of refrigerant leaving the heat rejecting heat
exchanger be as close as possible to the heat sink fluid (typically
air) entering the heat exchanger. The individual heat exchanger
segments or components could also be circuited to be as counterflow
as possible to further enhance this effect.
[0025] In FIG. 2, only one fan 34 is used to move the heat transfer
fluid (air) through all of the heat exchanger components 22, 24.
This is an additional benefit to cost and energy efficiency,
although this is not a necessary embodiment.
[0026] The segments or components of the heat exchanger could be
manufactured and shipped as one piece, or separately manufactured
and connected during the unit assembly process. This type of a heat
exchanger is particularly useful for applications where a low
number of fins are used on the heat exchanger for reasons of
fouling. The reduction in fins due to fouling concerns is offset by
the additional heat exchanger tube or channel surface area. This
heat exchanger could be a round tube plate fin, wire on tube,
microchannel, or any other configuration.
[0027] One or more embodiments of the present invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. For example, when implemented as a
remanufacturing of an existing system or reengineering of an
existing system configuration, details of the existing
configuration may influence details of the implementation.
Accordingly, other embodiments are within the scope of the
following claims.
* * * * *