U.S. patent application number 11/214774 was filed with the patent office on 2006-03-09 for heat exchanger arrangement particularly for motor vehicle.
This patent application is currently assigned to BEHR GmbH & CO.. Invention is credited to Peter Ambros, Peter Griesheimer, Reinhard Kull, Eberhard Pantow.
Application Number | 20060048922 11/214774 |
Document ID | / |
Family ID | 7873451 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060048922 |
Kind Code |
A1 |
Ambros; Peter ; et
al. |
March 9, 2006 |
Heat exchanger arrangement particularly for motor vehicle
Abstract
A heat exchange arrangement for a vehicle has at least two heat
exchangers exposed to the action of ambient air. One of the heat
exchanger is coolant cooler and the other one is a charge-air
coolant. Each of these coolers has tubes through which liquid or
gas flows and heat dissipating ribs connected to the tubes. The
coolant cooler is positioned upstream of the charge-air cooler in
the air-flow direction. The charge-air cooler has an overlapping
region in which the coolant cooler and the charge-air cooler
overlap one another and a non-overlapping region in which the
coolant cooler projects substantially perpendicularly to the
cooling air flow direction. The non-overlapping region is formed at
least in the charge-air outlet region and is cooled directly by
ambient cooling air. The overlapping region is cooled by the
ambient cooling air that has passed through the coolant cooler,
which is positioned immediately upstream of the overlapping region
of the charge-air cooler.
Inventors: |
Ambros; Peter;
(Kornwestheim, DE) ; Griesheimer; Peter;
(Stuttgart, DE) ; Kull; Reinhard; (Ludwigsburg,
DE) ; Pantow; Eberhard; (Stuttgart, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
BEHR GmbH & CO.
|
Family ID: |
7873451 |
Appl. No.: |
11/214774 |
Filed: |
August 31, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10307584 |
Dec 2, 2002 |
6957689 |
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11214774 |
Aug 31, 2005 |
|
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|
09350105 |
Jul 9, 1999 |
6619379 |
|
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10307584 |
Dec 2, 2002 |
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Current U.S.
Class: |
165/140 |
Current CPC
Class: |
F28D 2021/0082 20130101;
F02B 29/0456 20130101; Y02T 10/146 20130101; F01P 3/18 20130101;
F01P 2060/02 20130101; F02B 29/0493 20130101; F02B 37/00 20130101;
F01P 2060/16 20130101; F02B 29/0431 20130101; F01P 2003/187
20130101; F02B 29/0475 20130101; F28D 2021/0094 20130101; Y02T
10/12 20130101; F01P 2003/182 20130101; Y10S 165/903 20130101; F28D
1/0435 20130101; B60K 11/04 20130101; F02B 29/0412 20130101 |
Class at
Publication: |
165/140 |
International
Class: |
F28D 7/10 20060101
F28D007/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 1998 |
DE |
198 30 677.6 |
Claims
1-3. (canceled)
4. A heat exchanger arrangement comprising: a coolant cooler
exposed to ambient air and comprising a plurality of tubes through
which coolant to be cooled flows and heat dissipating ribs
connected to the tubes; and a charge-air cooler exposed to ambient
air and comprising a plurality of tubes through which hot charge
air flows and heat dissipating ribs connected to the tubes, the
charge-air cooler having a charge-air inlet region from which hot
charge air is introduced and a charge-air outlet region from which
cooled charge air exits, wherein the charge-air cooler is
positioned downstream of the coolant cooler relative to a direction
of cooling air flow, wherein the charge-air cooler has an
overlapping region in which the coolant cooler and the charge-air
cooler overlap one another and a non-overlapping region in which a
portion of the charge-air cooler projects substantially
perpendicularly to the cooling air flow direction, beyond the
coolant cooler, wherein the non-overlapping region is formed at
least in the charge-air outlet region and is cooled directly by
ambient cooling air, wherein the overlapping region is cooled by
ambient cooling air that cools the coolant cooler, and wherein the
charge-air cooler and the coolant cooler have substantially the
same surface area size and are offset with respect to one another
perpendicularly to the air-flow direction.
5. A heat exchanger arrangement comprising: a coolant cooler
exposed to ambient air and comprising a plurality of tubes through
which coolant to be cooled flows and heat dissipating ribs
connected to the tubes; and a charge-air cooler exposed to ambient
air and comprising a plurality of tubes through which hot charge
air flows and heat dissipating ribs connected to the tubes, the
charge-air cooler having a charge-air inlet region from which hot
charge air is introduced and a charge-air outlet region from which
cooled charge air exits, wherein the charge-air cooler is
positioned downstream of the coolant cooler relative to a direction
of cooling air flow, wherein the charge-air cooler has an
overlapping region in which the coolant cooler and the charge-air
cooler overlap one another and a non-overlapping region in which a
portion of the charge-air cooler projects substantially
perpendicularly to the cooling air flow direction, beyond the
coolant cooler, wherein the non-overlapping region is formed at
least in the charge-air outlet region and is cooled directly by
ambient cooling air, wherein the overlapping region is cooled by
ambient cooling air that cools the coolant cooler, and wherein the
charge-air cooler has a smaller surface area than the coolant
cooler and the charge-air cooler and the coolant cooler are offset
with respect to one another perpendicularly to the air-flow
direction.
6-11. (canceled)
12. A heat exchanger arrangement comprising: a coolant cooler
exposed to ambient air and comprising a plurality of tubes through
which coolant to be cooled flows and heat dissipating ribs
connected to the tubes: and a charge-air cooler exposed to ambient
air and comprising a plurality of tubes through which hot charge
air flows and heat dissipating ribs connected to the tubes, the
charge-air cooler having a charge-air inlet region from which hot
charge air is introduced and a charge-air outlet region from which
cooled charge air exits, wherein the charge-air cooler is
positioned downstream of the coolant cooler relative to a direction
of cooling air flow, wherein the charge-air cooler has an
overlapping region in which the coolant cooler and the charge-air
cooler overlap one another and a non-overlapping region in which a
portion of the charge-air cooler projects substantially
perpendicularly to the cooling air flow direction, beyond the
coolant cooler, wherein the non-overlapping region is formed at
least in the charge-air outlet region and is cooled directly by
ambient cooling air, wherein the overlapping region is cooled by
ambient cooling air that cools the coolant cooler, and wherein the
non-overlapping region of the charge-air cooler has a greater depth
in the air-flow direction than the overlapping region.
13-15. (canceled)
16. A heat exchanger arrangement comprising: a coolant cooler
exposed to ambient air and comprising a plurality of tubes through
which coolant to be cooled flows and heat dissipating ribs
connected to the tubes, a charge-air cooler exposed to ambient air
and comprising a plurality of tubes through which hot charge air
flows and heat dissipating ribs connected to the tubes the
charge-air cooler having a charge-air inlet region from which hot
charge air is introduced and a charge-air outlet region from which
cooled charge air exits; and at least one additional heat
exchanger, wherein the charge-air cooler is positioned downstream
of the coolant cooler relative to a direction of cooling air flow,
wherein the charge-air cooler has an overlapping region in which
the coolant cooler and the charge-air cooler overlap one another
and a non-overlapping region in which a portion of the charge-air
cooler projects substantially perpendicularly to the cooling air
flow direction, beyond the coolant cooler, wherein the
non-overlapping region is formed at least in the charge-air outlet
region and is cooled by ambient cooling air that does not pass
through the coolant cooler, wherein the overlapping region is
cooled by ambient cooling air that cools the coolant cooler, and
wherein said at least one additional heat exchanger is integrated
with at least one of the charge-air cooler and coolant cooler and
arranged downstream of and at least partially overlapping the
non-overlapping region of the charge-air cooler.
17. A heat exchanger arrangement according to claim 16, wherein the
additional heat exchanger is adapted to be connected to a coolant
circuit that is separate from the charge-air cooler and the coolant
cooler.
18. A heat exchanger arrangement according to claim 16, wherein the
additional heat exchanger is connected to the coolant cooler in a
common coolant circuit.
19. A heat exchanger arrangement according to claim 18, wherein the
additional heat exchanger adapted to further decrease the
temperature of the coolant.
20. A heat exchanger arrangement according to claim 17, wherein the
additional heat exchanger is an exhaust-gas heat exchanger.
Description
[0001] The present application is a divisional of U.S. application
Ser. No. 10/307,584, filed Dec. 2, 2002, which is a divisional of
application Ser. No. 09/350,105, filed Jul. 9, 1999 (now U.S. Pat.
No. 6,619,379), the entire contents of which are incorporated
herein by reference.
BACKGROUND
[0002] A coolant cooler dissipates excess heat produced by an
internal combustion engine of a motor vehicle to ambient air.
Moreover, with supercharged internal combustion engines, a
charge-air cooler cools air, which has been heated and compressed
in a supercharger, and dissipates heat to ambient air. The
operations of cooling charge air and coolant are fundamentally
different. The coolant undergoes only a small drop in temperature
because the coolant has a high heat capacity. A large heat quantity
thus can be exchanged even with slight cooling. In contrast, the
charge air temperature is considerably higher when it enters the
charge-air cooler and has to be considerably lower than that of the
coolant as the charge air exits.
[0003] Charge-air coolers can be air cooled or liquid cooled. In
liquid-cooled charge-air coolers, more straightforward charge-air
guidance is usually possible, and the overall volume of these
charge-air coolers can be smaller than the air-cooled design. If
the engine coolant cools the charge air, the charge air can only be
cooled approximately to the coolant temperature. If a lower
charge-air temperature is sought, it can only be achieved by an
additional coolant circuit that is capable of producing a lower
outlet temperature or, more straightforwardly, by air-cooled
charge-air coolers. The air-cooled design is widely used in
passenger cars and commercial vehicles. The charge-air coolers are
thus generally air-cooled charge-air coolers.
[0004] It is known from the publication ATZ Automobiltechnische
Zeitschrift (Automotive Journal) (1981), No. 9, pages 449, 450,
453, to arrange the charge-air coolers upstream of the coolant
cooler and have part of the end surface of the coolant cooler
overlap the charge-air cooler on the air side. The reason for this
arrangement is that, in the case of the charge-air cooler, a lower
target temperature has to be reached than in the case of the
coolant cooler. The lower target temperature is ensured by cooling
with fresh air flowing against the same. This conventional
arrangement is disadvantageous in that cooling air flowing on the
air side becomes heated to a very pronounced extent in the upstream
charge-air cooler. Because the heated air reaches the downstream
coolant cooler, it can only slightly cool the coolant in the
overlapping coolant-cooler part. The coolant cooler of such an
arrangement thus requires a relatively large surface area to
achieve the necessary cooling capacity. Moreover, very large
cooling-air streams are necessary, and they require in some cases
very high fan capacities.
[0005] European Patent Application EP 522 288 discloses a heat
exchanger arrangement that has a coolant cooler and a charge-air
cooler. The charge-air cooler is of split design and, in relation
to a cooling air stream, has one charge-air-cooler part located
upstream of the coolant cooler and one charge-air-cooler part
located downstream thereof. This arrangement makes it possible for
at least one part-surface of both of the charge-air cooler and of
the coolant cooler to be exposed to fresh air. Such an arrangement
has a disadvantage in that, on account of the charge-air cooler
being split into two charge-air-cooler parts, increased design
outlay is necessary, in particular in terms of the charge-air-side
connection of the two charge-air-cooler parts to one another for
passing on the charger from one charge-air-cooler part to the
other. Because this operation involves the charge air being passed
on, there is an additional pressure drop in the charge air.
Furthermore, there is an increase in the installation space, in
particular the installation depth in the air-flow direction within
the motor vehicle in comparison with a conventional arrangement,
since three heat-exchanger planes, namely the first part of the
charge-air cooler, the coolant cooler, and the second part of the
charge-air cooler, are arranged one behind the other on the air
side.
[0006] European Patent Application EP 522 471 discloses a heat
exchanger arrangement that has a coolant cooler and a charge-air
cooler. Both the coolant cooler and the charge-air cooler are of
split design. This arrangement likewise is disadvantageous in that
increased design outlay is necessary for passing on the charge air
and the coolant to the respectively associated charge-air-cooler
part and coolant-cooler part.
SUMMARY OF THE INVENTION
[0007] The present invention relates to a heat exchanger
arrangement that can reduce the design outlay. Furthermore, the
installation space, both in terms of the depth in the air-flow
direction and perpendicularly thereto, can be kept as low as
possible, to achieve the greatest possible heat-exchanging capacity
over a smallest possible surface area.
[0008] A heat exchanger arrangement according to the present
invention can comprise a coolant cooler and a charge-air cooler.
Both the coolant cooler and the charge-air cooler are exposed to
ambient air. The coolant cooler comprises a plurality of tubes
through which coolant to be cooled flows and heat dissipating ribs
connected to the tubes. The charge-air cooler similarly comprises a
plurality of tubes through which hot charge air to be cooled flows
and heat dissipating ribs connected to the tubes. The charge-air
cooler has a charge-air inlet region from which hot charge air is
introduced into the charge-air cooler and a charge-air outlet
region from which cooled charge air exits.
[0009] According the present invention, the charge-air cooler is
positioned downstream of the coolant cooler relative to the
direction of cooling air flow. The charge-air cooler has an
overlapping region in which the coolant cooler and the charge-air
cooler overlap one another and a non-overlapping region in which a
portion of the charge-air cooler projects substantially
perpendicularly to the cooling air flow direction, beyond the
coolant cooler. The non-overlapping region is formed at least in
the charge-air outlet region and is cooled directly by ambient
cooling air, whereas the overlapping region is cooled by the
ambient cooling air that cools the coolant cooler.
[0010] The surface area of the charge-air cooler can be smaller or
substantially the same, or larger than that of the coolant cooler.
The charge-air cooler and the coolant cooler can be offset with
respect to one another perpendicularly to the airflow
direction.
[0011] The density of the ribs of the charge-air cooler can be
greater in the non-overlapping region than in the overlapping
region. The density of the ribs and/or the mutual spacing of the
ribs on the outer surface and/or the interior of the charge-air
cooler can be varied. The spacing between the tubes of the
charge-air cooler can be smaller in the non-overlapping region than
in the overlapping region. The charge-air cooler can have a
multiple rows of tubes, with a greater number of tube rows in the
non-overlapping region than in the overlapping region. The
non-overlapping region of the charge-air cooler can also have a
greater depth in the air-flow direction than the overlapping
region.
[0012] According to another aspect of the invention, at least one
additional heat exchanger is arranged upstream of and at least
partially overlaps the non-overlapping region of the charge-air
cooler. The additional heat exchanger can be connected downstream
of the charge-air outlet region to further cool the charge air. The
additional heat exchanger can also be integrated with at least one
of the charge-air exchanger and coolant cooler and the additional
heat exchanger can be arranged upstream, downstream or alongside
thereof.
[0013] The additional heat exchanger is adapted to be connected to
a coolant circuit that is separate from the charge-air cooler and
the coolant cooler, such as an exhaust-gas cooling circuit, or that
is part of the charge-air or coolant cooling circuit. Thus, the
additional heat exchanger can be an exhaust-gas heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other features, aspects, and advantages of the
present invention will become more apparent from the following
description, appended claims, and accompanying exemplary
embodiments shown in the drawings, which are briefly described
below.
[0015] FIG. 1 shows a schematic side view of an arrangement of a
coolant cooler and a charge-air cooler.
[0016] FIG. 2 shows a front view of the arrangement of FIG. 1.
[0017] FIG. 3 shows a schematic view of the arrangement of a
charge-air cooler and a coolant cooler in the charge-air circuit
and the coolant circuit.
[0018] FIG. 4 shows a side view of a configuration of the
arrangement according to the invention of a coolant cooler and a
charge-air cooler.
[0019] FIG. 5 shows a front view of a further configuration of the
arrangement according to the invention of a coolant cooler and a
charge-air cooler.
[0020] FIG. 6 shows a schematic side view of a further
configuration of the invention with a varying rib density.
[0021] FIG. 7 shows a front view of FIG. 6.
[0022] FIG. 8 shows a schematic side view of a further
configuration of the invention with a varied depth of the
charge-air cooler.
[0023] FIG. 9 shows a front view of FIG. 8.
[0024] FIG. 10 shows a schematic side view of a further
configuration of the invention with a further heat exchanger.
[0025] FIG. 11 shows a front view of FIG. 10.
[0026] FIG. 12 shows a schematic side view of a further
configuration of the invention with a further heat exchanger.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] FIG. 1 shows two heat exchangers in the form of a charge-air
cooler 10 and of a coolant cooler 12, which are installed in an
engine compartment (not illustrated) of a motor vehicle. Each of
these coolers comprises a plurality of tubes through which either
liquid or gas flows, and heat dissipating ribs connected to the
tubes. The two heat exchangers are exposed to a cooling-air stream
14 on the air side and are serially arranged. The coolant cooler 12
is located, on the air side, upstream of the charge-air cooler 10.
In this embodiment, the coolant cooler 12 has a smaller cooling
surface than the charge-air cooler 10.
[0028] FIG. 2 shows termination edges 18b, 18c, and 18d of the
coolant cooler 12, which are arranged essentially parallel to the
termination edges 20b, 20c, and 20d of the charge-air cooler 10 and
are positioned essentially in alignment therewith in the air-flow
direction of the cooling-air stream 14. The coolant cooler 12 thus
overlaps an end-surface region 24 of the charge-air cooler 10 by
way of its entire end surface 22. Thus, only an end-surface region
26 of the charge-air cooler 10, which region is located between the
termination edges 20a and 18a, is not overlapped on the air side
and is thus subjected to the direct cooling-air stream 14 flowing
freely against it.
[0029] On the charge-air side, the charge-air cooler 10 has a
charge-air stream 16 flowing through it. The stream, as shown in
FIG. 3, is incorporated in a charge-air circuit between an internal
combustion engine 32 and the charge-air cooler 10. In this case,
the charge-air circuit is compressed by a compressor 28, which is
driven by an exhaust-gas air stream 30 of the internal combustion
engine 32, and fed through the charge-air cooler 10 of the internal
combustion engine 32. The charge-air cooler 10 cools the charge air
exhausting from the exhaust-gas air stream, which is compressed by
the compressor 28. The charge air enters the charge-air cooler 10
from a charge-air inlet side 34 at approximately 200.degree. K
above the ambient temperature. The charge-air exits the cooler 10
from a charge-air outlet region 36 at approximately 20.degree. K
above the temperature of the ambient air.
[0030] According to the embodiment of FIG. 3, the coolant cooler 12
is incorporated on the coolant side, in a coolant stream 38, where
the coolant from the internal combustion engine 32 circulates
through a control valve 40, the coolant cooler 12, and back to the
internal combustion engine 32. The coolant cooler 12 cools the
coolant heated by the internal combustion engine 32. The heated
coolant is introduced into the coolant cooler 12 at a temperature
of approximately 70.degree. K above the ambient temperature. The
temperature drop due to heat dissipation is in the range of a few
degrees Kelvin. The coolant stream 38 is driven by a coolant pump
42.
[0031] To assist the flow of the cooling-air stream of the ambient
air through both the coolant cooler 12 and the charge-air cooler
10, a fan 43 is arranged, on the air side, downstream of the heat
exchangers 12, 10.
[0032] The features of the present invention reside in the sequence
in which the coolant cooler 12 and the charge-air cooler 10 are
arranged in the cooling-air stream, and the overlap configuration.
Since the coolant cooler 12 according to FIG. 1 precedes before any
other heat exchanger, ambient cooling air, i.e., non-preheated
cooling-air stream 14, can flow directly against it and take
advantage of the maximum heat dissipating capability of the ambient
cooling air stream.
[0033] The charge-air cooler 10 according to FIG. 1 is positioned
immediately downstream of the coolant cooler 12, which has a
smaller dimension than the charge-air cooler 10. Thus, a portion of
the charge-air cooler 10 overlaps the coolant cooler 12.
Specifically, the upper portion of the charge-air cooler extending
below from the charge-air inlet side 34 forms an overlapping
region. The overlapping region of the charge-air cooler thus
receives cooling air 14 that has passed through the coolant cooler
12 and thus preheated by the coolant cooler 12. The temperature
difference between the charge air flowing through the interior of
the charge-air cooler and the cooling air 14 that acts on the
charge-air cooler 10 from the outside, becomes smaller than had the
ambient cooling air 14 flowing directly against the charge-air
cooler. Since the charge-air, however, enters into the charge-air
cooler 10 at approximately 200.degree. K above the ambient
temperature and the cooling air is only preheated to around
70.degree. K above the ambient air temperature, there is still a
large temperature difference between the preheated cooling-air
stream 14 reaching the charge-air cooler and the charge air. This
temperature difference is sufficient for the cooling air to
dissipate heat from the charge air and lower the charge air
temperature to about 70.degree. K above the ambient air
temperature.
[0034] Since the target temperature of the charge air flowing out
of the charge-air outlet region 36 is approximately 20.degree. K
above the ambient air temperature, it would not always be possible
to cool the charge air to the target temperature using only the
cooling air 14 preheated by the coolant cooler 12. According to the
invention, the charge-air cooler 10 has a second portion projecting
beyond the fast or overlapping region 24 to further reduce the
temperature of the charge air to the desired target temperature by
blowing ambient cooling air 14, which is not preheated, directly
against the second or non-overlapping region 26.
[0035] The essential factor here is that the non-overlapping region
26, where the charge air is finally brought to the target
temperature, is arranged, downstream of the first region 24 in the
charge air flow direction, to make it possible to fully utilize the
above-mentioned advantages of the temperature differences. The
direction in which the coolant is delivered by the coolant cooler
12 plays a lesser role in comparison with the direction of the
charge-air stream. Moreover, in the present example, FIG. 1
illustrates a situation where the coolant stream 38 flows
horizontally from left to right through the coolant cooler 12.
Alternatively, flow may also take place from right to left, from
top to bottom or, conversely, from bottom to top. Moreover, the
non-overlapping region 26, which is provided in the top region of
the arrangement in the installed position in FIG. 1, may also
alternatively be arranged, depending on individual requirements, in
the bottom region. A lateral arrangement of the non-overlapping
region 26 is likewise conceivable.
[0036] FIG. 4 shows a different way of forming overlapping and
non-overlapping regions. In this case, two heat exchangers, which
in the installed position can have the same height or of different
heights, are offset heightwise with respect to one another so that
a region that has air flowing directly against it also is formed in
the upper region. Analogously, it is likewise possible for heat
exchangers of the same width or of different widths to be offset in
the lateral direction, as is illustrated in FIG. 5. Such an
arrangement assists the installation in vehicle regions that do not
have a rectangular installation opening.
[0037] A further improvement in the heat-exchanging capacity of the
arrangement as a whole can be achieved by increasing the density of
the heat dissipating ribs of the charge-air cooler in the
non-overlapping region 26 and/or reducing the density of the ribs
in the overlapping region 24. Alternatively, the density of the
ribs of the coolant cooler can be coordinated in certain regions or
in full. FIGS. 6 and 7 show such an arrangement where the
charge-air cooler 10 has an overlapping region 10a and
non-overlapping region 10b, 10c, and 10d. The non-overlapping
region 10b has a greater rib density than that of the overlapping
region 10a. The non-overlapping regions 10c and 10d, which are
subjected to direct cooling-air stream 14, can also have the same
density as the overlapping region 10a. The density of the ribs can
be adapted in each case to optimize the heat-exchanging capacity.
Also, the density of the ribs and/or the mutual spacing of the ribs
on the outer surface and/or the interior of the charge-air cooler
can also be varied.
[0038] A similar effect can be achieved by increasing the depth of
the non-overlapping region 48 of the charge-air cooler 10, as shown
in FIGS. 8 and 9. Alternatively, in the case of a multi-row design,
similar results can be obtained by increasing the number of tube
rows.
[0039] In another embodiment, as shown in FIGS. 10 and 11, the
charge-air cooler 10 can be a two-part design having a
charge-air-cooler part 44 and a low-temperature charge-air-cooler
part 46 connected in series, on the air side, upstream of the
charge-air-cooler part 44. In this case, the low-temperature
charge-air-cooler part 46 can be arranged parallel to the
single-part coolant cooler 12. The charge-air-cooler-part 44 and
the low temperature charge-air-cooler part 46 are connected in
series on the charge-air side. Thus, the charge air is first
directed through the charge-air-cooler part 44 and then is fed to
the low-temperature charge-air cooler part 46 via connecting lines
50. This further improves the heat-exchanging capacity with just
two heat-exchanging planes, namely a first plane having the coolant
cooler 12 and the low-temperature charge-air-cooler part 46 and a
second plane having the charge-air-cooler part 44.
[0040] FIG. 12 shows an arrangement of a coolant cooler 12, a
charge-air cooler 10, and an additional heat exchanger 52 having a
cooling-air stream 14 flowing through them. In this case, the
additional heat exchanger 52 is arranged, on the air side,
downstream of the coolant cooler 12 and the charge-air cooler 10,
and is arranged behind the non-overlapping region 26 of the
charge-air cooler 10.
[0041] The additional heat exchanger 52 may have the task of
guiding a partial coolant stream that has been branched off from
the main coolant circuit of the coolant cooler 12, or may be
completely isolated therefrom. In the latter case, the additional
heat exchanger 52 serves to cool an additional heat source, for
example an exhaust-gas heat exchanger.
[0042] By situating the coolant cooler 12 upstream of the
charge-air cooler 10 in the air-flow direction, and projecting the
charge-air cooler 10 beyond the dimension of the coolant cooler 10
at least in the charge-air outlet region 36, so that a portion of
the charge-air cooler overlaps the coolant cooler. Because the
coolant cooler 12 is arranged upstream of the charge-air cooler 10,
with at least the side on which the charge air is discharged from
the charge-air cooler 10 is not overlapping with the coolant
cooler, it is possible to use a considerably smaller coolant cooler
than in the case of the conventional arrangement. By virtue of the
present arrangement, the temperature of the cooling-air stream that
has been preheated by the coolant cooler is in each case much
cooler than the temperature of the charge-air cooler arranged
downstream on the air side. The target temperature of the
charge-air cooler, which is lower than attainable from the
preheated coolant cooler, is finally achieved by the
non-overlapping portion of the charge-air cooler having the ambient
air flowing directly against it.
[0043] It has surprisingly been found that, within the context of
simulation calculations, in comparison with the conventional
arrangement, the arrangement according to the invention, with
equivalent charge-air cooling, allows the coolant temperature to be
additionally reduced by approximately 5.degree. K. In comparison
with the conventional arrangement, the present arrangement, with
the same heat-exchanging surface area, provides an improved
heat-exchanging capacity or, with the same heat-exchanging
capacity, alternatively needs less heat-exchanging surface area,
saving space.
[0044] The charge-air cooler 10 can have a larger area than the
coolant cooler 12. This makes it possible to form a region of the
charge-air cooler that is not overlapping on the air side with the
coolant cooler 12. That is, the two heat exchangers 10, 12 are
arranged essentially in alignment one behind the other on up to
three of the four sides on the air side, which efficiently uses the
entire surface area for the heat exchange.
[0045] The charge-air cooler 10 and the coolant cooler 12 can be
offset with respect to one another perpendicularly to the air-flow
direction. Such an offset arrangement increases the surface area of
the non-overlapping region(s) and makes it possible to have the
coolant cooler 12 and charge-air cooler 10 to have the same size or
area, or different sizes. In this case, such an offset arrangement
may be effected in a horizontal and/or in a vertical direction in
relation to the installed position in the motor vehicle, to assist
the installation of the coolant cooler 12 and charge-air cooler 10
in non-rectangular installation space.
[0046] In a further configuration of the invention, the charge-air
cooler 10 can have a smaller area than or the same area as the
coolant cooler 12, with the two heat exchangers being offset with
respect to one another perpendicularly to the air-flow direction.
The charge-air cooler 10 is arranged downstream of the coolant
cooler 12, and has a portion projecting beyond the coolant cooler
12 in the charge-air outlet region 36. This arrangement provides a
region in which, on account of the smaller or the same area size,
there is no overlapping of the end surfaces of the two heat
exchangers. This type of arrangement is advantageous, in
particular, when, for cooling the charge air, the heat-exchanging
surface area required in the overlapping region is smaller than the
end surface of the coolant cooler 12. This likewise achieves
favorable utilization of the cooling-air stream and makes it being
possible for the charge-air cooler 10 to be smaller in terms of its
end surface, and thus less expensive.
[0047] The local density of the ribs of the charge-air cooler 10
can be greater in the non-overlapping region than in the
overlapping region, as set forth analogously in the applicant's
German patent application No. 198 13 069. This reduces any
inhomogeneity in terms of the air speed between the overlapping and
non-overlapping regions, and thus also an inhomogeneity in the heat
exchange, and there is an increase in heat-exchange capacity of the
arrangement as a whole. In this case, it is possible for both the
air-side ribs, on the outer surface of the charge-air cooler, and
also in addition, or as an alternative, for the charge-air-side
ribs, in the interior of the charge-air cooler, to have their
mutual spacing varied. It is not necessary, however, for the
density and the degree of change in density of the inner and outer
ribs to be the same. Preferably, however, with an increase in the
rib density on the outside, an increase in the rib density on the
inside will also be carried out. In comparison with the
above-mentioned arrangement, which already provides advantages of
its own, such a variation in the rib density achieves a further
substantial improvement. Simulation calculations show that, in
comparison with the conventional arrangement, the present
arrangement, with equivalent charge-air cooling, allows the coolant
temperature to be additionally reduced by approximately 10.degree.
K.
[0048] The spacing between the tubes (tube division) of the
charge-air cooler can be smaller in the non-overlapping region than
in the overlapping region. This likewise increases the
heat-exchanging capacity and makes it possible for a variation in
the spacing between the tubes of the charge-air cooler to take
place both alone and in combination with a variation in the rib
density.
[0049] In a further configuration of the invention, the charge-air
cooler can have a plurality of rows of tubes located one behind the
other on the air side, the number of non-overlapping regions of
tube rows of the charge-air cooler being greater than that of the
overlapping region. This likewise increases the heat-exchanging
capacity of the arrangement, a combination with the above-mentioned
possible variations being conceivable.
[0050] The depth of the charge-air cooler in the air-flow direction
can be greater in the non-overlapping region than in the
overlapping region. This makes it possible to vary the depth both
in the direction of the air flow and in the direction counter to
this, as well as in both directions. The above-mentioned advantages
are also achieved by such a variation. Again, a combination with
the above-mentioned possible variations is conceivable.
[0051] In a further configuration of the invention, at least one
additional heat exchanger is arranged, on the air side, upstream of
the non-overlapping region of the charge-air cooler. The additional
heat exchanger overlaps at least partially the non-overlapping
region of the charge-air cooler. The additional heat exchanger can
project laterally beyond the end surfaces of the coolant cooler
and/or charge-air cooler. The number of heat-exchanger planes is
not increased by an additional heat exchanger arranged this way
since it is incorporated in the existing plane. This heat exchanger
may be, for example, a low-temperature heat exchanger intended for
charge-air cooling and connected in series with the charge-air
cooler on the charge-air side.
[0052] In another embodiment, at least one additional heat
exchanger is arranged, on the air side, upstream or downstream of
the heat exchangers 10, 12, or alongside the same. The additional
heat exchanger can be integrated with the charge-air cooler or
coolant cooler. This allows module formation from a number of heat
exchangers. The additional heat exchanger may be, for example, a
condenser or gas cooler belonging to an air-conditioning system and
can overlap at least partially or project beyond the arrangement
comprising the coolant cooler and the charge-air cooler. The
additional heat exchanger may also be a subsidiary oil cooler or
another heat exchanger exposed to the action of air.
[0053] The additional heat exchanger can be connected to a coolant
circuit that is separate from the charge-air cooler and the coolant
cooler, thus making it possible for the temperature level of the
isolated coolant circuit to be coordinated individually.
[0054] In a further configuration of the invention, the further
heat exchanger can be connected, along with the coolant cooler, to
a common coolant circuit, making it possible for the additional
heat exchanger to be designed as a low-temperature heat exchanger
or as an exhaust-gas heat exchanger.
[0055] The present invention is used, in particular, in the field
of commercial vehicles, but it can likewise be used in passenger
cars and other engine operated machines in which both coolant
coolers and charge-air coolers are used.
[0056] It is likewise possible for this invention to be combined
with temperature-control systems within the context of
thermo-management for cooling circuits, as described, for example,
in the publication MTZ Motortechnische Zeitschrift (Engine Journal)
(1996), No. 7/8, pages 424-428.
[0057] Although references are made in here to directions in
describing the structure, they are made relative to the drawings
(as normally viewed) for convenience. The directions, such as left,
right, upper, lower, etc., are not intended to be taken literally
or limit the present invention.
[0058] Given the disclosure of the present invention, one versed in
the art would appreciate that there may be other embodiments and
modifications within the scope and spirit of the present invention.
Accordingly, all modifications attainable by one versed in the art
from the present disclosure within the scope and spirit of the
present invention are to be included as further embodiments of the
present invention. The scope of the present invention accordingly
is to be defined as set forth in the appended claims.
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