U.S. patent application number 11/864099 was filed with the patent office on 2008-04-17 for heat exchanger.
Invention is credited to Stefan Muller-Lufft, Harald Schatz, Bjorn Volquardsen.
Application Number | 20080087410 11/864099 |
Document ID | / |
Family ID | 39184954 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080087410 |
Kind Code |
A1 |
Muller-Lufft; Stefan ; et
al. |
April 17, 2008 |
HEAT EXCHANGER
Abstract
The invention relates to a heat exchanger in which a liquid
coolant and a gaseous flow, for example compressed charge air, are
involved in the exchange of heat, with at least two heat exchanger
blocks being provided which can be traversed by the coolant and by
the gaseous flow. The invention can include inventive solutions for
a flat arrangement including at least one gas-side bypass arranged
adjacent to or within the first heat exchanger block and/or
adjacent to or within the second heat exchanger block. The present
invention also provides a method for cooling that divides the
gaseous flow into at least two partial flows. One partial flow can
be guided past a heat exchanger block, and the other partial flow
can be conducted through the other heat exchanger block before the
partial flows are finally merged.
Inventors: |
Muller-Lufft; Stefan;
(Leonberg, DE) ; Schatz; Harald; (Reutlingen,
DE) ; Volquardsen; Bjorn; (Boblingen, DE) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH LLP
100 E WISCONSIN AVENUE, Suite 3300
MILWAUKEE
WI
53202
US
|
Family ID: |
39184954 |
Appl. No.: |
11/864099 |
Filed: |
September 28, 2007 |
Current U.S.
Class: |
165/165 |
Current CPC
Class: |
Y02T 10/12 20130101;
F28D 9/0093 20130101; F02B 29/0462 20130101; F28D 9/0062 20130101;
F28F 2250/102 20130101; F28D 9/0056 20130101; Y02T 10/146 20130101;
F28D 9/0043 20130101; F28D 2021/0082 20130101 |
Class at
Publication: |
165/165 |
International
Class: |
F28D 7/02 20060101
F28D007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2006 |
DE |
102006048667.6 |
Claims
1. A heat exchanger for transferring heat between a liquid coolant
flow and a gaseous flow, the heat exchanger comprising: a pair of
heat exchanger blocks being traversed by the coolant flow and the
gaseous flow; a gas bypass arranged adjacent to or within the first
heat exchanger block; and a gas bypass arranged adjacent to or
within the second heat exchanger block, a first partial flow of the
gaseous flow being directed through the gas bypass of the first
heat exchanger and a second partial flow of the gaseous flow being
directed through the gas bypass of the second heat exchanger.
2. The heat exchanger of claim 1, wherein one bypass is arranged at
one side of the first heat exchanger block, and wherein an other
bypass is situated at an opposite side of the second heat exchanger
block.
3. The heat exchanger of claim 1, wherein one bypass is arranged at
a side of the first heat exchanger block and an other bypass is
situated at a corresponding side of the second heat exchanger
block.
4. The heat exchanger of claim 1, wherein the heat exchanger blocks
are arranged so as to be offset in height with respect to a flow
direction of the gaseous flow.
5. The heat exchanger of claim 1, wherein the heat exchanger blocks
are arranged at a common height with respect to a flow direction of
the gaseous flow.
6. The heat exchanger of claim 1, wherein the blocks are spaced
apart, and wherein at least one guide for conducting the first and
second partial flows extends through the space between the heat
exchanger blocks.
7. The heat exchanger of claim 1, wherein the blocks bear directly
against one another and have different heights, and wherein one of
the bypasses is arranged at least on or in the flatter block.
8. The heat exchanger of claim 1, wherein insulation can be
provided between the bypass and one of the pair of the heat
exchanger blocks.
9. A method of transferring heat between a gaseous flow and a
liquid coolant in a heat exchanger having at least two heat
exchanger blocks, the method comprising the acts of: dividing the
gaseous flow into at least two partial flows; directing a first
partial flow through one of the two heat exchanger blocks;
directing a second partial flow through another of the two heat
exchanger block; and merging the one and the other partial
flows.
10. The method of claim 9, wherein the first partial flow is guided
past a first one of the pair of heat exchanger blocks, wherein the
second partial flow is conducted through the first heat exchanger
block, wherein the first and second partial flows are conducted
through the second heat exchanger block, and wherein the first and
second partial flows are merged either at the second heat exchanger
block or downstream therefrom.
11. The method of claim 9, wherein the second partial flow is
directed past the first heat exchange block, and wherein the first
partial flow is directed past the second heat exchanger block
through the second heat exchanger block, and wherein another
partial flow is guided past the second heat exchanger block before
being merged with the second partial flow.
12. The method of claim 9, wherein the coolant flow is initially
conducted into the second heat exchanger block and subsequently
into the first heat exchanger block.
13. The method of claim 9, wherein the coolant flow is initially
conducted into the first heat exchanger block and subsequently into
the second heat exchanger block.
14. The method of claim 9, wherein the coolant flow which flows
through the one of the two heat exchanger blocks belongs to a
different circuit than the coolant flow which flows through the
other of the two heat exchanger blocks.
15. The method of claim 14, wherein the coolant which flows through
the one of the two heat exchanger block being different than the
coolant flow which flows through the other of the two heat
exchanger blocks.
16. The method of claim 14, wherein the coolant which flows through
the one of the two heat exchanger block being the same as the
coolant flow which flows through the other of the two heat
exchanger blocks.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is hereby claimed to German Patent Application No.
DE 10 2006 048 667.6, filed Oct. 14, 2006, the entire contents of
which is incorporated herein by reference.
FILED OF THE INVENTION
[0002] The present invention relates to a heat exchanger
arrangement in which a liquid coolant flow and a gaseous flow, such
as, for example, compressed charge air, are involved in the
exchange of heat, with at least two heat exchanger blocks being
provided which can be traversed by the coolant flow and by the
gaseous flow. The present invention also relates to a method for
the exchange of heat between a gaseous flow and a liquid coolant
flow.
SUMMARY
[0003] DE-A 2 655 017 discloses a relevant heat exchanger. DE 199
62 391 A1 discloses a further developed heat exchanger. The heat
exchanger of DE-A 2 is constructed for the purpose of pre-cooling
charge air. A first exchange of heat is carried out between
lubricating oil of the internal combustion engine and compressed
charge air in a first heat exchange block, and in a second heat
exchanger block, a second exchange of heat is carried out between
the cooling liquid of the internal combustion engine and the charge
air leaving the first heat exchanger block. In order to obtain
favorable overall conditions, this document also describes the
possibility of coolant-side bypasses. In this way, the combustion
air can be pre-heated at idle or in the partial-load range of the
internal combustion engine (see, for example FIG. 6 and
description, page 9 of said document).
[0004] DE 2 923 852 also discloses a conventional heat exchanger.
EP 1 279 805 A2 discloses a further-developed design. Here, the
charge air is initially cooled with liquid and subsequently by
cooling air, with the two heat exchangers forming a common
arrangement.
[0005] There are additionally several further disclosures in the
field of charge air cooling. Also, singled out from the multitude
is EP 522 471 B1 which describes and shows an air-cooled charge air
cooler arrangement in which the heat exchanger block is divided
into two sub-blocks, with one sub-block having been arranged for
example upstream of the radiator which is acted on with cooling
air, and the other sub-block having been arranged offset in height
with respect to and downstream of the radiator. The charge air
initially flows into the first sub-block and thereafter into the
second sub-block via a connecting duct or the like. In this way,
the cooling capacity of the entire cooler arrangement can be raised
or at least positively influenced.
[0006] The physical configuration of the heat exchanger and its
arrangement is delegated to specialists who are to implement the
specifications of the user, for example of the motor vehicle
manufacturer. The specifications involve inter alia the attainment
of a low pressure loss with sufficient cooling power under usually
restricted spatial conditions.
[0007] In particular, the charge air, which is compressed with high
energy expenditure, is to be cooled and arrive at the engine under
high pressure, which means that the charge air pressure may not be
reduced to too great a degree before said point as a result of
necessary cooling measures etc. In addition, the installation space
of the heat exchanger arrangement can, for example, be situated
beneath the drive unit, with it being necessary to maintain a
certain degree of ground clearance. The obvious measure which a
person skilled in the art would implement would possibly be that of
designing the heat exchanger arrangement to be not particularly
high but rather to be substantially flat, wherein the entire heat
exchanger area would need to remain unchanged in order to be able
to provide the demanded cooling capacity. Said measure would
however not be satisfactory from the point of view of the pressure
loss, which is known to increase with longer flow paths of the heat
exchanger block.
[0008] Finally, EP 1 491 837 A1 discloses a heat exchanger which is
embodied as a cooler for recirculated exhaust gases, but which
however could be a charge air cooler. In said document, an exhaust
gas bypass is provided, through which the entire exhaust gas flow
approaching the heat exchanger is to flow in certain operating
states of the internal combustion engine of a vehicle.
[0009] It is an object of the invention to produce and provide a
heat exchanger arrangement which is of flat construction and can
inter alia meet the demands for a low pressure loss. In order to
solve these and other problems, a working method for cooling, for
example, charge air is also to be provided.
[0010] The present invention provides improvements to exiting heat
exchangers. Because in each case one gas-side bypass is arranged
adjacent to the first and preferably also adjacent to the second
heat exchanger block, an arrangement of flat construction is
provided which is characterized by a low pressure loss, which is to
be attributed to the bypasses. The bypasses are essentially
relatively smooth-walled tubes through which the partial flows of
the, for example, charge air can flow without experiencing
noticeable pressure loss. In the present context, the term
"adjacent" means either above or below, to the left-hand side or to
the right-hand side or an arrangement in which the bypass and the
heat exchanger block run adjacent to one another in some other
manner. The bypass could also be situated within a heat exchanger
block, which is likewise to be covered by the attribute or the
feature "adjacent".
[0011] The heat exchanger arrangement of the present invention can
be situated entirely within a compact housing, with it then being
possible, but not strictly necessary, for the bypass to run
directly along a housing wall.
[0012] In contrast, it is however possible for each heat exchanger
block to also be designed to be of the housingless type, with the
bypass being integrated therein. Situated between the two heat
exchanger blocks is then a type of partial housing or a device for
carrying out a deflection of the partial flows.
[0013] The present invention also provides a heat exchanger having
a single bypass arranged at one side of the first heat exchanger
block, and a second bypass situated at the other side of the second
heat exchanger block. It is possible, in contrast, for one bypass
to be arranged at one side of the first heat exchanger block and
the other bypass to be situated at the same side of the second heat
exchanger block.
[0014] Here, it is expedient for the heat exchanger blocks to be
arranged so as to be offset in height as viewed in the flow
direction of the gaseous flow. This is favorable if one bypass is
situated above the first heat exchanger block and the other bypass
is situated below the second heat exchanger block. The present
invention alternatively provides heat exchanger blocks which are
arranged at a common height as viewed in the flow direction of the
charge air.
[0015] In order to correspondingly deflect the partial flows, the
present invention also provides at least one device for conducting
the partial flows between the heat exchanger networks. Here, the
one partial flow is to be conducted from the first bypass into the
second heat exchanger block, and the second partial flow
approaching from the first heat exchanger block can be deflected
into the second bypass.
[0016] If only one bypass is provided, the heat exchanger blocks
can have different heights. The bypass is situated on the flatter
block. The as yet uncooled charge air enters into the higher second
block together with the charge air which is already cooled in the
first block.
[0017] In order to suppress thermal influences, the present
invention can provide insulation arranged between the bypass and
the heat exchanger block. The insulation can also be provided in
the form of an air gap between the bypass and the heat exchanger
block.
[0018] The method for cooling, for example, charge air, with a
liquid coolant, with a charge air flow and a liquid coolant flow
being conducted through at least two heat exchanger blocks,
includes the acts of a) dividing the charge air into at least two
partial flows, b) guiding one partial flow past a heat exchanger
block, c) conducting one partial flow through a heat exchanger
block, and d) merging the partial flows.
[0019] In some embodiments of the present invention, the sequence
of the steps can be varied. It can for example be the case that the
division of the flow into partial flows is carried out only after
the flow passes through the first block. The merging of the partial
flows can take place after the flow passes through the entire
arrangement, or alternatively, even within a block. In some
embodiments, it can be advantageous for the liquid coolant flow to
be initially conducted into the second heat exchanger block and
subsequently into the first heat exchanger block. Liquid coolant
can also be a two-phase coolant.
[0020] In other embodiments, the coolant flow can initially be
conducted into the first heat exchanger block and subsequently into
the second heat exchanger block. This ultimately means that the two
heat exchanger networks can be situated in the same cooling
circuit.
[0021] Depending on the concrete requirements, however, the heat
exchanger of the present invention can include a plurality of
cooling circuits, with each heat exchanger network being connected
into different cooling circuits or air-conditioning circuits, and
thereby being operated with liquid coolant or refrigerant.
[0022] In the arrangement of the present invention, it is possible
for two identically-designed heat exchanger blocks to be used,
which has definite production-related advantages. It is also
possible to use different heat exchanger blocks in one
arrangement.
[0023] The heat exchanger blocks can be constructed from stacked
plate pairs, with in each case one plate pair forming, in its
interior, a flow duct for the coolant. In each case one flow duct,
which is provided with turbulators, for the charge air is situated
between the plate pairs. A housing can enclose the stack.
[0024] In contrast, the heat exchanger blocks can be constructed
from flat tubes with or without inner inserts, and from fins or the
like which are arranged between the flat tubes, similarly to a
radiator block. A housing can enclose the stack.
[0025] The heat exchanger blocks can however also be constructed as
plate heat exchangers with trough-shaped heat exchanger plates, or
alternatively, can be of bar/plate design, with it being possible
for the bypass to be designed as a bypass line past a plate heat
exchanger. Finally, the blocks can also be constructed according to
further known principles.
[0026] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is perspective view of a heat exchanger according to
a first exemplary embodiment of the present invention.
[0028] FIG. 2 shows a partial perspective view of the heat
exchanger shown in FIG. 1.
[0029] FIGS. 3 and 4 show a heat exchanger according to a second
exemplary embodiment.
[0030] FIGS. 5 and 6 show a heat exchanger according to a third
exemplary embodiment.
[0031] FIG. 7 is an exploded perspective view of a heat exchanger
block of the present invention.
DETAILED DESCRIPTION
[0032] Before any embodiments 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 arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, it is to be 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,"
"comprising," or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items. Unless specified or limited otherwise,
the terms "mounted," "connected," "supported," and "coupled" and
variations thereof are used broadly and encompass both direct and
indirect mountings, connections, supports, and couplings. Further,
"connected" and "coupled" are not restricted to physical or
mechanical connections or couplings.
[0033] The heat exchanger arrangements shown and described below
could also be used in other applications, such as, for example, as
an exhaust gas heat exchanger in motor vehicles. Alternatively or
in addition, the heat exchanger arrangements could be used for any
other desired purpose which is dependent on the lowest possible
pressure loss, for example, on the gas side and which are
constructed with a relatively flat design.
[0034] The depicted heat exchanger arrangements represent charge
air coolers and are thus referred to as such below. In the charge
air cooler, the compressed charge air is cooled by a cooling liquid
of the engine of a utility vehicle. In FIG. 1, the charge air is
shown by solid arrows and the cooling liquid is shown by dashed
arrows. The charge air cooler is of flat construction, because it
should be fastened (not shown) to the underside of the drive unit
of a utility vehicle. For this purpose, the charge air cooler is
equipped with a plurality of connectors 10. Illustrated are four
cantilevers which have bores at their ends.
[0035] The charge air cooler has a housing G in which are situated
two heat exchanger blocks A and B. The first heat exchanger block A
as viewed in the flow direction of the charge air is arranged
slightly lower than the second heat exchanger block B. Situated
above the first heat exchanger block A is a bypass C. Situated
below the second heat exchanger block B is a further bypass C.
[0036] The compressed and heated charge air entering through the
inlet is, in this exemplary embodiment, divided into two partial
flows. The first partial flow passes through the first bypass C and
the second partial flow flows through the first heat exchanger
block A. The second partial flow leaving the first heat exchanger
block A has correspondingly been cooled and flows via the second
bypass C in the direction of the outlet. It is possible for
insulation to be provided therein in order to prevent the partial
flow being heated again. The first partial flow passing from the
first bypass passes through the second heat exchanger block B in
order to likewise be cooled.
[0037] Downstream of the second heat exchanger block B, the two
partial flows are merged and are made available as a cooled charge
air flow, which has been only slightly reduced through pressure
loss, for charging the internal combustion engine (not shown). A
cross section which is drawn in FIG. 1 can also effectively
demonstrate the above-described substantive matter with regard to
the working method carried out with the arrangement. In the
illustrated embodiments, the inlets and outlets are constructed as
relatively smooth-walled tubes which can generate only a negligible
pressure loss. The interior of the heat exchanger blocks A and B is
designed so as to generate a division into partial flows.
[0038] The heat exchanger blocks A and B can be of substantially
identical design. Situated between the two heat exchanger blocks A
and B is a guide device D which provides the described guidance of
the partial flows. The guide device D is of a flow-promoting shape.
In the exemplary embodiment, both heat exchanger blocks A and B are
traversed in series at the liquid side by the cooling liquid, as is
intended to be indicated by the dashed lines. Because, in the
exemplary embodiment, all of the inlets and outlets for the cooling
liquid are situated on one side, it is clear that each heat
exchanger block A and B is traversed by the cooling liquid in a
U-shape, while the charge air can flow transversely with respect
thereto but on a straight path through the heat exchanger blocks A
and B. In FIG. 2, the U-shaped throughflow has been indicated at
the heat exchanger block B. Here, only one "U" has been indicated.
It is however also possible for multiple U-shaped loops, that is to
say a meandering flow, to be provided.
[0039] In contrast to the described exemplary embodiment, the heat
exchanger blocks A and B in FIGS. 3 and 4 are situated at a common
height, and the bypasses C have been arranged at opposite ends of
the heat exchanger blocks A, B. A guide device D is provided
between the blocks A and B.
[0040] In the exemplary embodiment shown in FIGS. 5 and 6, three
partial flows are provided on the charge air side. With the
selected throughflow, the charge air passes through two bypasses C
which are situated at the outside of the first heat exchanger block
A, and through a bypass C which is situated at the inside of the
second heat exchanger block B. The throughflow direction can be
selected both on the charge air side and also on the liquid side.
The first heat exchanger block A is situated approximately at a
central region in the housing G in which the one bypass C is also
situated. The second heat exchanger block B, which could also be
composed of two heat exchanger blocks, is situated in the two outer
regions in the housing G in which the two bypasses C are situated.
The guide device D is composed here of two walls, as the figures
show. The exemplary embodiments shown already reveal that at least
some further variations of the arrangement of heat exchanger blocks
and bypasses, which have all of the steps of the working method,
are possible and appear to be expedient. For example, it is also
possible for more than two heat exchanger blocks to be arranged in
series in the flow direction of the charge air.
[0041] FIG. 7 shows a partially exploded illustration of a heat
exchanger block which is suitable for the proposed arrangement. The
heat exchanger block is composed of heat exchanger plates 2 which
form in each case one pair. At the opposite ends, each plate pair
in the exemplary embodiment shown is closed off by inserted rods 3
and 4. At the longitudinal sides, the plates 2 are provided with
shaped edge flanges in order to close off the space within a plate
pair.
[0042] The cooling liquid flows within each pair. The plates 2 are
formed with beads 7 or similar formations in such a way that the
cooling liquid must pass through a plurality of U-shaped paths in
order to pass from the inlet to the outlet. Arranged between the
pairs are corrugated fins 5 or similar elements, through which one
partial flow of the charge air flows. The block arrow is intended
to show this. The stack of plates 2 and corrugated fins 5 is
provided at the top and at the bottom with one closure plate 1, 6
which are formed to be slightly more stable than the other plates
2. Blocks of this type can be arranged within the housing G which
is shown. It is however also possible to use blocks of some other
design, which need not strictly be situated in a housing G which is
closed off at all sides. It is also possible for one block to be
arranged in a housing G and for the other block to be designed to
be of the housingless type.
[0043] Various features and advantages of the invention are set
forth in the following claims.
* * * * *