U.S. patent application number 10/193796 was filed with the patent office on 2003-01-23 for heat exchanger for a thermal coupling.
Invention is credited to Dienhart, Bernd, Frohling, Jorn, Heyl, Peter.
Application Number | 20030015310 10/193796 |
Document ID | / |
Family ID | 7692112 |
Filed Date | 2003-01-23 |
United States Patent
Application |
20030015310 |
Kind Code |
A1 |
Dienhart, Bernd ; et
al. |
January 23, 2003 |
Heat exchanger for a thermal coupling
Abstract
A heat exchanger, particularly for a thermal coupling of a
glycol/water cooling system circuit and a refrigerant circuit in a
motor vehicle includes a plurality of first plates having first
flow channels for refrigerant and a first reservoir in fluid
communication with the first flow channels integrally formed
therein, a plurality of second flow plates having second flow
channels for a glycol/water mixture, and a second reservoir mounted
to a side of said heat exchanger and in fluid communication with
the second flow plates.
Inventors: |
Dienhart, Bernd; (Koeln,
DE) ; Frohling, Jorn; (Koeln, DE) ; Heyl,
Peter; (Koeln, DE) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60611
US
|
Family ID: |
7692112 |
Appl. No.: |
10/193796 |
Filed: |
July 12, 2002 |
Current U.S.
Class: |
165/41 |
Current CPC
Class: |
F28D 9/0043 20130101;
F28F 3/04 20130101; F28F 2250/102 20130101; F28D 2021/0073
20130101 |
Class at
Publication: |
165/41 |
International
Class: |
F28F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 12, 2001 |
DE |
101 34 761.8 |
Claims
What is claimed is:
1. A heat exchanger, particularly for a thermal coupling of a
glycol/water cooling system circuit and a refrigerant circuit in a
motor vehicle comprising: a plurality of first plates having first
flow channels for refrigerant and a first reservoir in fluid
communication with said first flow channels integrally formed
therein; a plurality of second flow plates having second flow
channels for a glycol/water mixture; a second reservoir mounted to
a side of said heat exchanger and in fluid communication with said
second flow plates.
2. The heat exchanger of claim 1 wherein said second reservoir is
mounted onto said heat exchanger such that said second reservoir is
aligned within the same plane as said first reservoirs.
3. The heat exchanger of claim 1 wherein said second reservoir is
mounted onto said heat exchanger such that said second reservoir is
offset from said first reservoirs by 90 degrees.
4. The heat exchanger of claim 1 wherein said first and second flow
channels are single flow channels.
5. The heat exchanger of claim 1 wherein said first and second flow
channels are multi-flow channels.
6. The heat exchanger of claim 1 wherein each of said first flow
channels has a hydraulic diameter that is between about 0.1
millimeters and about 4 millimeters.
7. The heat exchanger of claim 1 wherein each of said second flow
channels has a hydraulic diameter that is between about 1
millimeter and about 6 millimeters.
8. The heat exchanger of claim 1 wherein the shape of said first
collectors are one of either circular, oval, elliptical,
rectangular, or as an elongated hole.
9. The heat exchanger of claim 1 wherein each of said first and
second plates have a wall thickness that is between about 0.2
millimeters and about 5 millimeters.
10. The heat exchanger of claim 1 wherein the shape of said first
and second flow channels are one of either circular, semicircular,
wedge-shaped, ribbed, or non-ribbed.
11. The heat exchanger of claim 1 wherein said first flow channels
and said second flow channels are arranged such that flow of the
refrigerant through said heat exchanger is either countercurrent
flow, cross flow, or parallel flow relative to flow of the
glycol/water mixture.
12. The heat exchanger of claim 1 wherein said second reservoir
includes a plurality of separators to divide the second collectors
into different chambers.
13. A heat exchanger, particularly for a thermal coupling of a
glycol/water cooling system circuit and a refrigerant circuit in a
motor vehicle comprising: a plurality of first plates having first
flow channels for refrigerant and a first reservoir in fluid
communication with said first flow channels integrally formed
therein, said first flow channels having a hydraulic diameter that
is between about 0.1 millimeters and about 4 millimeters; a
plurality of second flow plates having second flow channels for a
glycol/water mixture, said second flow channels having a hydraulic
diameter that is between about 1 millimeter and about 6
millimeters; a second reservoir mounted to a side of said heat
exchanger and in fluid communication with said second flow plates
and including a plurality of separators to divide the second
reservoir into different chambers; each of said first and second
plates having a wall thickness that is between about 0.2
millimeters and about 5 millimeters.
14. The heat exchanger of claim 13 wherein said second reservoir is
mounted onto said heat exchanger such that said second reservoir is
aligned within the same plane as said first reservoirs.
15. The heat exchanger of claim 13 wherein said second reservoir is
mounted onto said heat exchanger such that said second reservoir is
offset from said first reservoirs by 90 degrees.
16. The heat exchanger of claim 13 wherein said first and second
flow channels are single flow channels.
17. The heat exchanger of claim 13 wherein said first and second
flow channels are multi-flow channels.
18. The heat exchanger of claim 13 wherein the shape of said first
collectors are one of either circular, oval, elliptical,
rectangular, or as an elongated hole.
19. The heat exchanger of claim 13 wherein the shape of said first
and second flow channels are one of either circular, semicircular,
wedge-shaped, ribbed, or non-ribbed.
20. The heat exchanger of claim 13 wherein said first flow channels
and said second flow channels are arranged such that flow of the
refrigerant through said heat exchanger is either countercurrent
flow, cross flow, or parallel flow relative to flow of the
glycol/water mixture.
Description
BACKGROUND OF INVENTION
[0001] 1. Technical Field of Invention
[0002] The present invention generally relates to a heat exchanger,
particularly for thermal coupling of a glycol/water circuit and a
refrigerant circuit in motor vehicles.
[0003] 2. Description of the Prior Art
[0004] Heat exchangers are apparatuses, or components, through
which heat is indirectly transferred from a first fluid mass flux
having a first temperature to a second fluid mass flux having a
second temperature, lower than the first temperature. The first and
second fluid mass fluxes are separated from one another and pass
through the heat exchanger without mixing.
[0005] In a motor vehicle having an internal combustion engine,
heat which is generated by the combustion process of the engine is
typically disposed to the environment by a cooling system within
the vehicle. Under certain operational conditions it is useful to
divert a portion of this heat to the interior of the vehicle to
heat the passenger compartment. The use of a heat pump makes it
possible to use this heat within the passenger compartment.
However, because of the low temperature of the diverted heat it is
necessary to transfer the heat from the glycol/water circuit of the
cooling system to the refrigerant circuit of the heat pump.
[0006] Many generic heat exchangers have been developed for this
type of application. Some heat exchangers are particularly designed
to handle fluid mass fluxes having high fluid pressures. Other heat
exchangers developed for use of different refrigerants in cooling
plants/heat pump processes have very small flow cross-sections and
filling capacities. In one such heat exchanger, adapted for use
with refrigerants at high pressures, the refrigerant passes through
the heat exchanger in flat tubes having refrigerant channels of
small diameters. Ribs extend between the flat tubes to position the
flat tubes at a distance from one another. These flat tubes define
an air-refrigerant heat exchanger, used as an evaporator in a
cooling plant.
[0007] Such a heat exchanger is not suitable for use with a thermal
coupling used to interconnect a glycol/water cooling system circuit
and a refrigerant circuit. The size of a heat exchanger of this
size prevents the use of a heat exchanger of this type as an
additional heat exchanger within a motor vehicle.
[0008] Another type of heat exchanger used flat tubes that are
designed to be used with refrigerant at high temperatures, such at
a refrigeration circuit using carbon dioxide as the refrigerant.
Heat exchangers of this type are not suitable for use with a
thermal coupling used to interconnect a glycol/water cooling system
circuit to a refrigerant circuit.
[0009] It is therefore an object of this invention to provide a
heat exchanger, particularly for exchanging heat between a
refrigerant circuit and a glycol/water cooling system circuit,
whereby the heat exchanger has a small physical size and works at
high rates of transferred heat fluxes, while simultaneously meeting
the safety requirement necessary to operate with high pressure
refrigerants.
SUMMARY OF THE INVENTION
[0010] The disadvantages of the prior art are overcome by providing
a plate heat exchanger having a plurality of first plates with
first flow channels for refrigerant and a plurality of second
plates with second flow channels for glycol/water mixture. A
reservoir for the first plates is integrally formed with the first
plates, and a second reservoir for the second plates is mounted to
an outer side of the heat exchanger, whereby the second reservoir
can be arranged on the same plane with the first reservoir, or
offset by 90 degrees from the first reservoir.
[0011] According to another aspect of the present invention, the
refrigerant or the glycol/water mixture flows in a plane, whereby
the heat between the refrigerant and the glycol/water mixture is
transferred in cross and/or parallel flow, countercurrent flow,
cross countercurrent flow, or cross concurrent flow. The described
heat exchanger has connections for refrigerant inflow, refrigerant
outflow, glycol/water mixture inflow, and glycol/water mixture
outflow, or is directly connected to another heat exchanger. That
is, in particular, the environment of the heat exchanger/cooler of
the glycol/water circuit.
[0012] In yet another aspect of the present invention, the heat
exchanger is designed such that safety requirements are fulfilled
due to small flow cross-sections of the refrigerant channels and a
small total filling volume of the heat exchanger.
[0013] In still another aspect of the present invention, the heat
exchanger has a relatively small size while providing a large
heat-transferring surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a heat exchanger made from
plates;
[0015] FIG. 2 is a top view of a plate having flow channels for
refrigerant formed therein;
[0016] FIG. 3 is a top view of a plate with flow channels for a
glycol/water mixture;
[0017] FIG. 4 is a top view of a heat exchanger of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The following description of the preferred embodiment of the
invention is not intended to limit the scope of the invention to
this preferred embodiment, but rather to enable any person skilled
in the art to make and use the invention.
[0019] Referring to FIG. 1, a heat exchanger of the present
invention is shown generally at 1. The heat exchanger 1 is made of
a plurality of first and second plates 2, 4. The first plates
include first flow channels 3 which are adapted to allow
refrigerant to flow therethrough. The second plates 4 have second
flow channels 5 which are adapted to allow a glycol/water mixture
to flow therethrough. The flow channels 3, 5 can be designed as
either single flow or multi-flow channels.
[0020] The heat exchanger 1 has connections for refrigerant inflow,
refrigerant outflow, glycol/water mixture inflow, and glycol/water
mixture outflow, or alternatively is directly connected to another
heat exchanger 1. Preferably, the heat exchanger uses a refrigerant
such as carbon dioxide (R744), tetrafluoroethane (R134a), or
propane (R290), however, it is to be understood, that other
suitable refrigerants could be utilized without departing from the
scope of the present invention.
[0021] Preferably, the first and second plates 2, 4 of the heat
exchanger 1 are made of a flat material. The first and second flow
channels 3, 5 are created by a mechanical forming process, such as
pressing or stamping, milling, etching or laser machining.
Preferably, the first and second plates 2, 4 are arranged
alternately and form a plate pack.
[0022] The wall thickness of the first and second plates 2, 4
depends upon the particular application, however, preferably, the
first and second plates 2, 4 have a wall thickness that is between
about 0.2 millimeters and about 5 millimeters. The first and second
plates 2, 4 can be attached to one another by soldering, brazing,
welding, or other suitable means.
[0023] Referring to FIG. 2, the first plates 2 include first
reservoirs 6 for the refrigerant. The flow channels 3 pass through
the plate 2 in a preferably meandering manner and connect the first
reservoirs 6 within each plate. Preferably, the first reservoirs 6
within the first plates 2 are integrally formed within the first
plates 2. Depending upon the application, the refrigerant, and
geometrical conditions, the first reservoirs 6 can be shaped either
circular, oval, elliptical, rectangular, or as an elongated
hole.
[0024] The flow channels 3, 5 in the plates 2, 4 can be circular,
semicircular, wedge-shaped, ribbed or not ribbed. Further, the
first flow channels 3 of the first plates 2 have a hydraulic
diameter of between about 0.1 millimeters and about 4 millimeters.
The second flow channels 5 of the second plates 4 have a hydraulic
diameter of between about 1 millimeter and about 6 millimeters.
[0025] The hydraulic diameter is defined as the product of the
cross-sectional area of the flow channels 3, 5 multiplied by four
and then divided by the distance around the periphery of the
cross-section of the flow channels 3, 5. Therefore, for a flow
channel having a circular cross-section, the hydraulic diameter is
equal to the diameter of the circular cross-section.
[0026] Referring to FIG. 3, a second plate 4 having flow channels 5
for the glycol/water mixture includes distance pieces 8, and
passage openings 9 for the refrigerant to connect the first
reservoirs 6 of two adjacent first plates 2 with one another.
Second reservoirs 7 are mounted to either side of the plate pack,
in fluid communication with the second flow channels 5 of the
second plates 4. The second flow channels 5 extend across the
second plates 4 to interconnect the second reservoirs 7.
Preferably, the second flow channels 5 are linear and extend across
the second flow channels 5 at an angle to the sides of the plate
pack.
[0027] Referring to FIG. 4, in an alternate embodiment, the second
reservoirs 7 of the second plates 4 includes separators 10. The
separators 10 divide the reservoirs 7 into separate chambers.
Therefore, the glycol/water mixture passes through only part of the
second flow channels 5 in the second plates 4 from one reservoir 7
to the opposite reservoir 7, and from the opposite reservoir 7
through the remaining second flow channels 5 in the same second
plate 4, back to the original reservoir 7.
[0028] Depending upon the arrangement of the first and second flow
channels 3, 5 and the separators 10 in the heat exchanger 1, any
type of flow pattern, such as countercurrent flow, cross flow,
parallel flow and concurrent flow can be realized partially or
totally.
[0029] The foregoing discussion discloses and describes the
preferred embodiments of the invention. One skilled in the art will
readily recognize from such discussion, and from the accompanying
drawings and claims, that changes and modifications can be made to
the invention without departing from the scope of the invention as
defined in the following claims. The invention has been described
in an illustrative manner, and it is to be understood that the
terminology which has been used is intended to be in the nature of
words of description rather than of limitation.
* * * * *