EP2044319A1

EP2044319A1 - Device for cooling a gas flow of an internal combustion engine

Info

Publication number: EP2044319A1
Application number: EP07786061A
Authority: EP
Inventors: Peter Geskes; Bernd GRÜNENWALD; Wolfgang KNÖDLER; Jens Ruckwied; Jürgen BARWIG
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2006-07-14
Filing date: 2007-07-13
Publication date: 2009-04-08
Also published as: US20090277165A1; JP5220008B2; JP2009543994A; WO2008006604A1; US8936070B2

Abstract

The invention relates to a device for cooling a gas flow of an internal combustion engine, comprising a housing (1), an inlet (3) and an outlet (4) for a gas, in particular exhaust gas and/or charge air of the internal combustion engine, which is to be cooled, an inlet (18) and an outlet (16) for an in particular liquid coolant, an exchanger means (5) for heat transfer between the gas and the coolant, a first wall section (1 a) of the housing (1), wherein the first wall section (1 a) is arranged between the coolant and the gas flow, and a second wall section (1 b) of the housing (1), wherein the second wall section (1 b) is arranged between the coolant and an environment, in particular the atmosphere, wherein the first wall section (1 a) and the second wall section (1 b) are materially integrally formed in one piece.

Description

Device for cooling a gas flow of an internal combustion engine

The present invention relates to a device for cooling a gas flow of an internal combustion engine according to the preamble of claim 1.

For the reduction of pollutants, especially in diesel engines of passenger cars, the recirculation of exhaust gas to the internal combustion engine is increasingly used, wherein the exhaust gas must be cooled before the return. For this purpose, heat exchangers are known, which include exchanger tubes made of stainless steel due to the high temperatures and high corrosivity of the exhaust gas. Such exchanger tubes are connected via holding means such as bottom pieces with a coolant-carrying housing, wherein the production of such heat exchangers is generally expensive. In addition to exhaust gas can under a gas flow in the context of the invention charge air z. B. from a turbocharger or an exhaust-air mixture are understood. These gas streams also often require cooling before being fed to the internal combustion engine in order to ensure the function and efficiency of the internal combustion engine.

It is the object of the invention to provide a device for cooling a gas flow of an internal combustion engine, which is inexpensive and can be produced with little installation effort. This object is achieved by the invention with an aforementioned device in which the characterizing features of claim 1 are provided according to the invention. Due to the integral formation of material of the two wall sections a separation of the environment and coolant and a separation of coolant and gas flow is at least partially ensured by the same one-piece component. This allows a particularly favorable production of the housing, since this does not have to be composed of several components, at least in the areas of the wall sections, either by mechanical fastening using sealants or be it by soldering or welding. The unitary material formation in the sense of the invention comprises a uniform, seamless production of the two wall sections comprehensive housing part.

In an advantageous embodiment, the first and the second wall portion of the housing made of a light metal, in particular based on aluminum. Aluminum is both easy to build and inexpensive moldable. Particularly preferably, the molding of a housing part comprising the first and the second wall section takes place as a cast part, in particular a diecast part. This cost-effective production of a lightweight housing is especially in the case of cooling a hot exhaust stream at least in the region of the exhaust gas inlet into the housing, especially made possible by the fact that the aluminum is cooled directly by the particular liquid coolant. The coolant may be, for. B. to act the main coolant of the engine and / or an additional, in particular cooled to ambient temperature cooling circuit.

In an advantageous embodiment, the cast housing part has a first demoulding side and a second demolding side, wherein the first demolding side for guiding the coolant and the second demoulding side mung side is designed to guide the gas. As a result, complex shaped partitions between coolant and gas can be produced in a simple manner at the same time simple casting process. In particular, a large number of shapes are possible without the necessary use of expensive casting cores.

In a further possible embodiment, a housing part comprising the first and the second wall section is designed as an extruded profile. Extruded profiles are particularly inexpensive to produce and can have very complex cross-sectional shapes. In addition, it has been found that especially in conventional extrusion processes of aluminum alloys, a crystalline structure of the aluminum is achieved, which has a particularly good corrosion resistance. As a result, the cooling of hot, corrosive exhaust gas is well possible. Important in the use of extruded profiles in particular for the cooling of exhaust gas is the avoidance of a subsequent strong heating of the pressed profiles, such as in a brazing furnace, since in this case the good corrosive properties can be lost again.

In an alternative embodiment, the first and the second wall portion of the housing may be formed of a one-piece sheet metal part, which consists in particular of a stainless steel. Depending on the dimensioning of the housing with the wall sections, such sheet metal forming can take place by means of simple deep-drawing, which results in cost-effective production with little scrap.

In a generally preferred embodiment, the housing comprises at least one cover part which is not formed in one piece with the wall sections. Advantageously, sealing means for sealing the coolant and / or the gas are provided on the cover part. Here, the cover part z. B. are bolted to the other housing. Alternatively or additionally, the Cover part also be sealingly soldered to the other housing. If both the cover part and the housing are made of a light metal alloy based on aluminum, such a soldering of a mechanically preassembled heat exchanger can take place, for example, in a brazing furnace. Depending on the design, it can also be a local soldering or welding process.

In the interest of a simple construction and manufacture, at least one of the two, the supply or the discharge of the coolant, is arranged on the cover part.

Particularly preferably, the cover part has a channel for guiding the coolant, so that the cover part itself can be cooled. As a result, the cover part come into contact with the hot gas stream even when produced from light metal. In a simple and cost-effective embodiment, the cover part has at least two, in particular three, plate-like elements arranged on top of each other, wherein the channel is formed by a recess in at least one of the plate-like elements. Such a layered structure of the cover part of a plurality of plate elements is particularly space-saving and easy to manufacture. Furthermore, the cover part preferably has an overflow opening for connecting the channel to the further housing. As a result, both the cover part and the further housing can be flowed through and cooled by means of a single supply of the coolant.

The exchange means is formed in an advantageous embodiment as in particular connected to the cover part module. In this way, a supply or discharge of the coolant can be provided on the cover part, wherein in addition a preliminary test for reducing the rejects in the production is made possible in a simple manner. In an exemplary embodiment, the exchange means is designed as a stack of disks, wherein in particular the stack can be flowed through by the coolant and can be flowed around by the gas. In this way, a simple to manufacture embodiment of the exchange means is given, which also has a high exchange performance with a small size and can be integrated inexpensively and easily into the housing of the device according to the invention.

Alternatively, the exchange means may also be formed as a casting, in particular die casting with a plurality of cooling fins. As a result, the exchange means can be produced particularly inexpensively. Furthermore, alternatively, the exchange means may also comprise a tube bundle.

Preferably, the exchange means is formed as arranged in the housing module. This allows z. B. manufacture the exchanger means of non-rusting steel, whereby a high reliability and high exchange performance is given in a small space. In an alternative advantageous embodiment, however, the exchange means may also be formed integrally with the first and second wall sections in the same material. This leads to a particularly cost-effective production with a particularly small number of individual parts and thus a high level of operational safety. In this case, the exchanger means preferably has a plurality of ribs which can be flowed around by the gas and formed in one piece with the first wall section, thereby increasing the contact surface between the first wall and gas in order to optimize the cooling performance.

In the interest of a compact design with high heat exchanger performance, the device is designed as a U-flow cooler. Depending on requirements, it may alternatively be an I-flow cooler. In particular, in the case of the I-flow construction, the device preferably comprises a bypass channel, which in the case of I-flow coolers geometric reasons usually separate is provided in addition to the exchange means, whereas in U-flow cooling mostly the possibility of a bypass deflection of the gas flow from the supply to the discharge in the inlet region of the U-flow heat exchanger is possible.

In a further detail improvement of a preferred embodiment, a valve member for adjustable deflection of the gas stream is arranged in the housing. As a result, the means for deflection, for example for bypass deflection, are integrated into the housing in a modular manner, which results in a compact design. Alternatively or additionally, a valve member for adjustable regulation of a total size of the gas flow is arranged in the housing. In a particularly preferred embodiment, which is optimized in terms of installation space and number of components, a deflection of the gas flow through the exchange means or a bypass path can also be adjusted via the valve member.

In the context of a first preferred variant of the invention, it has proved to be advantageous that the first and / or the second wall section is a cooled wall section. This can be achieved in particular in that both the first wall section and the second wall section are arranged directly adjacent to the coolant, so that advantageously results in both a cooling of the first wall section and the second wall section.

In particular, for this purpose, the first wall section, preferably practically completely, can be arranged inside the housing. In addition, it has proven to be advantageous that the second wall portion practically completely forms a housing outer wall of a housing part and / or a housing. In particular, it is to be understood that the second wall section completely up to areas of the supply and discharge of the gas to be cooled, a housing outer wall of a housing part and / or a housing forms. In the context of the aforementioned development, the housing can be designed and manufactured in a particularly simple manner, the advantages of the concept of the invention being realized.

Within the scope of a likewise deviating likewise preferred development of the invention, provision may be made for the second wall section to form a housing outer wall of a housing part and / or of a housing only in a first partial area. In particular, this relates only to a first sub-area except for areas of supply and discharge of the gas to be cooled. It has proved particularly expedient in the context of the aforementioned development that the first subregion is essentially limited to those regions of a housing part and / or of the housing which are in contact with comparatively hot, in particular uncooled, gas. This preferably relates to input and / or bypass areas of a housing part and / or a housing. This results in particular in the advantage that the second wall section has to be designed practically only in the first partial area provided in this development as a wall section adjoining the coolant. In other words, within the scope of this development of the invention, measures for the design of the second wall section beyond the first partial area are omitted in order to form the second wall section as a coolant-adjacent wall section. In principle, a section of the second wall section housing can also be arranged on the inside.

It has been found that the aforementioned development of the invention has proven to be particularly advantageous in the context of a second variant of the invention, in which the housing has a further third wall section. Preferably, according to the second variant, the first wall portion and the second wall portion and the third wall portion may be formed integrally materially in one piece according to the concept of the invention. This results in the comparison with the first variant of the invention given where appropriate, to be preferred advantage that the third wall section is interpreted uncooled. The third wall portion can thus be particularly easy to interpret in an advantageous manner.

As part of a development of the second variant of the invention, the third wall section in a further, second subregion form a housing outer wall of a housing part and / or a housing. It has proved to be expedient that the second subregion is essentially limited to those regions of a housing part and / or of the housing which are in contact with comparatively cooler gas, in particular cooled and / or partially cooled gas. This applies in particular to regions which are arranged adjacent to the exchange means and / or deflection regions of a housing part and / or a housing. In other words, it has been recognized in the context of the second variant of the invention that there are areas of housing parts and / or areas of the housing, which need not necessarily be cooled and therefore a corresponding third wall section - compared to the second wall section - designed comparatively simple can be.

The second wall portion and the third wall portion may together form virtually completely a housing outer wall of a housing part and / or a housing. In other words, the second wall section and the third wall section can form a housing outer wall of a housing part and / or a housing completely, except for regions of the feed and discharge of the gas to be cooled. A section of the third wall section may also be arranged inside the housing.

It has proved to be particularly advantageous in the context of the second variant of the invention that the third wall section can be made with a thinner wall than the second wall section. For example, it is possible to provide the second wall section with a wall thickness which in approximately corresponds to the wall thickness of the first wall portion. In principle, as explained above, the third wall section can advantageously be designed to be simpler than the second wall section. According to the aforementioned development, it has proven to be particularly expedient to achieve a Materia spam by a thinner-walled design, which also leads to a weight advantage and a space savings in the device of the aforementioned type.

In a further development of the device according to the invention, the housing may be designed as part of an intake module of the internal combustion engine. In particular, in the case of the invention such integration of a gas cooler in the intake module is made possible in a simple manner. For example, the housing or even a cover part may be formed integrally with the intake module. Intake modules of modern internal combustion engines are usually aluminum castings, so that the optimization of space and cost integration of the cooling elements with the intake ports of the internal combustion engine is desirable to a common module.

While the invention has been found to be particularly useful for and to use a heat exchanger in the form of an exhaust gas heat exchanger, and while the invention is described in detail below by examples of heat exchange between an exhaust of an internal combustion engine and a coolant, so should Nevertheless, it should be understood that the concept described herein, as claimed, is also useful in the context of other applications that are outside of the heat exchange between exhaust gas and coolant in the strict sense and relate to applications that are outside of these ranges, such as the heat exchange between one Coolant and a charge air and / or an exhaust gas and / or a charge air-exhaust gas mixture. For example, the concept presented could also be used for be used in which compared to the applications described flow paths of coolant and gas / exhaust gas / charge air are reversed, ie the flow paths described below for a gas / exhaust gas / charge air are provided and vice versa for gas / exhaust / Charge air described flow paths are provided to a coolant. In particular, this relates to the exemplary embodiments of FIGS. 12, 13 and 14 which are described below and which are versatile.

In principle, the exemplary embodiments described below, in particular the exemplary embodiments according to FIGS. 12, 13 and 14, are also suitable for providing a vaporizable medium in the flow paths of the coolant as coolant. In this case, the heat exchanger is formed in the form of an evaporator. This can be particularly useful if the hot medium used in the flow paths for gas / exhaust gas / charge air gives off its heat for evaporation of the vaporizable medium, for example a water, a refrigerant or other vaporizable fluids. Such a heat exchanger in the form of a cooler can be particularly preferably arranged behind an exhaust gas turbine, expediently on a low-pressure side of an internal combustion engine, in order to use the exchanged heat, for example in a Rankine cycle. Likewise, such a heat exchanger can be designed according to the principle of a cooler as a capacitor. In this case, in the flow paths described below for coolant, i. in the embodiments of Figs. 12, 13 and 14 in the outer flow paths, a condensable medium is guided and in the following for exhaust / gas / charge air provided flow paths, i. In the exemplary embodiments of FIGS. 12, 13 and 14 in the case of the internal flow paths, a cooling medium is provided for the flow.

Embodiments of the invention will now be described below with reference to the drawing. This is not intended to represent the embodiments significantly, but the drawing, where appropriate for explanation, in schematized and / or slightly distorted shape executed. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art.

It should be noted that various modifications and changes in form and details of an embodiment can be made without departing from the general idea of the invention. The features of the invention disclosed in the foregoing description, in the drawing and in the claims may be essential both individually and in combination for the development of the invention. In addition, fall within the scope of the invention, all constructions of at least two of the features disclosed in the description, the drawings and / or the claims. The general idea of the invention is not limited to the exact form or detail of the embodiment shown and described below or limited to an object which would be limited in comparison with the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and be arbitrarily usable and claimable.

Further advantages and features of the invention will become apparent from the embodiments described below and from the dependent claims.

Hereinafter, several embodiments of the invention will be described and explained in more detail with reference to the accompanying Fig. The drawing.

Fig. 1 shows a schematic representation of a first embodiment according to a first variant of the invention with a separately shown cover part. 007/006237

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Fig. 2 shows a schematic plan view of the embodiment of Fig. 1 from the side.

Fig. 3 shows a coolant side plan view of a second embodiment according to a first variant of the invention. FIG. 4 shows a gas side view of the embodiment from FIG.

3.

5 shows a spatial schematic view of a third embodiment according to a first variant of the invention.

FIG. 6 shows the exemplary embodiment from FIG. 5, omitting an uppermost plate element of a lid.

Fig. 7 shows the embodiment of Fig. 6 omitting a central plate member of the lid.

FIG. 8 shows a spatially open view of the exemplary embodiment from FIGS. 5 to 7 from a gas side. FIG. 9 shows the exemplary embodiment from FIGS. 5 to 8 in an opened position

View from a coolant side.

Fig. 10 shows a sectional view of the device of Fig. 8 along the line A-A.

11 shows a schematic top view of an exchange means arranged on a cover from the side.

Fig. 12 shows a schematic sectional view through a further embodiment.

Fig. 13 is a perspective view of a housing of the embodiment of Fig. 12. Fig. 14 is a sectional view of a housing of another embodiment.

15 shows a gas-side plan view - similar to that in FIGS. 1, 4 or 8 for a further embodiment according to the second variant of the invention, in which the cooler is operated in the U-flow. Fig. 16 shows a gas-side plan view as in Fig. 15 for a further embodiment according to the second variant of the invention in which the cooler is operated in I-flow.

Fig. 17 shows schematically a complete intake module, the right part of an exhaust gas cooler and in the lower part of a coolant-cooled intercooler is installed and are shown in dashed lines in the cooled wall areas.

In the exemplary embodiments described below, functionally identical parts are designated by the same reference numerals. In the case of solid arrows, the flow arrows shown in the drawings are flows of the gas to be cooled and, in the case of broken arrows, coolant flows.

The first embodiment according to FIG. 1 comprises a housing 1 which is produced by die casting from an aluminum alloy. In Fig. 1, the housing 1 is shown in an open form next to a cover part 2, wherein the cover part 2 is shown in a schematic sectional view for the representation of arranged in the cover part 2 coolant channels.

The housing 1 comprises a feed 3 and a discharge 4 for a gas flow of an internal combustion engine. The device or the heat exchanger according to FIG. 1 serves to cool a recirculated exhaust gas stream 60 exemplified in FIG. 17 for the purpose of reducing pollutants of an internal combustion engine 50 of a motor vehicle.

The housing 1 has a first, inner wall section 1a and an outer, the first wall section 1a spaced circumferential wall portion 1b. The inlets and outlets 3, 4 formed as connecting pieces are arranged at openings of the outer wall 1b and open into a space 1a enclosed by the first, inner wall on three sides. In This space is arranged a exchange means 5, which is provided as a separate module within the inner wall 1a. The exchange means 5 is a heat sink, which can be traversed by a liquid coolant by means of connections 5a, 5b. Between the inlet and the outlet 3, 4, which are arranged side by side on the same side of the housing 1, an inlet region 6 is provided for the gas flow within the first wall 1a. On the other side of the heat sink 5 with respect to the gas flow, a deflection region 7 is provided between the inner wall 1a and the heat sink 5. In addition, in the entry region 6, a movable actuator 9 in the form of an adjusting flap is provided on suitably designed guide structures 8. By means of this adjusting flap 9, the exhaust gas flow can be adjusted selectively either directly from the feed 3 to the discharge 4 or passed through the heat sink 5. Thus, a bypass operation can be selected by the actuator 9, which may be desired depending on the operating state of the internal combustion engine.

Between the inner wall portion 1 a and the outer wall portion 1 b remains a narrow gap 1 c for the flow of coolant. As a result, in particular the inner wall section 1a is cooled, which is required above all in the inlet region 6 due to the high temperatures of the exhaust gas flow, since the housing 1 consists of an aluminum alloy.

The housing 1 is formed at least with the inner wall portion 1 a and the outer wall portion 1 b as integrally molded die-cast part.

A lower bottom 10 of the housing 1 may also be einstückig with the

Wall sections 1a, 1b may be formed in the die-casting process. In the plan view according to FIG. 1, a one-sided demolding of the casting Given that both the gas-conducting region and the coolant-carrying region would be formed by the same mold side.

In a possible modification, the housing 1 with the wall sections 1a and 1b can also be a section of an extruded profile. In this case, the coolant-side bottom part 10 would be placed separately, and it could expedient similar to the cover part described below 2 channels for the passage of coolant and thus for cooling the bottom part 10 in the region of contact with the gas stream. In any case, however, the wall portion 1 a, which separates the gas flow from the coolant flow and the wall portion 1 b, which separates the coolant flow from the environment material integrally formed.

The cover part 2, which forms an upper cover of the housing 1, is composed of a total of three plate elements 2 a, 2 b, 2 c (see FIG. 2), which are made of aluminum and are soldered to one another flatly. Each of the

Plate elements 2a, 2b, 2c has suitable openings, the one

Serving distribution of the liquid coolant. The upper plate member 2a has an opening for connecting a supply 11 for the coolant. The middle plate member 2b shown in the plan view in FIG. 1 has

Channels 12, 13, 14 in which the coolant flows in the plane of the lid part 2. The lower plate member 2c has openings 15, by means of which a connection of the channels 12, 13, 14 on the one hand to the exchanger means 5 and on the other hand with the coolant leading rooms 1c of the housing 1 between the walls 1 a, 1 b are prepared.

As shown in particular in the sectional view of FIG. 2, the entire coolant flows through the feed 11 and the opening in the upper plate member 2a in the channel 12 of the central plate member 2b and by a congruent opening of the lower plate member 2c in the exchange means 5. After circulation in the exchange means 5, the coolant enters through a further opening of the lower plate member 2c in the channel 13 of the central plate member 2b, from which it is passed via the channels 14 in a coolant-carrying shaft 1d of the housing 1. This shaft 1 d is connected to a nozzle 16 for the discharge of the coolant from the housing 1. The shaft 1d is located in the inlet region 6 of the gas flow and is closed off on one side by the outer wall 1b in the immediate vicinity of the feed 3 and outlet 4 of the gas flow. In this way, this temperature-critical region of the wall 1 b is cooled.

The partial flow of the channel 12 of the central plate element 2 b is passed through an opening 15 of the lower plate member 2 c in a gap 1 c circulating the greater part of the housing 1, so that the largest possible part of the contacting with the gas flow Wandab- section 1 a by the coolant is cooled. By means of suitable perforations in the lower plate element 2 c and the channels 14 of the middle plate element 2 b, this partial flow is also supplied to the part 1 d, so that the entire coolant leaves the housing 1 via the discharge connection 16.

In the present case, the exchange means 5 represents a module which is connected to the cover part 2 and is separate from the housing 1. An exemplary embodiment of the exchange means 5 is shown in FIG. 11. The exchange means 5 is constructed as a stack of discs 5c, as in a similar manner z. B. from stacked disc oil coolers are known. The stack of discs 5c forms a total of a cavity 5d to flow through the coolant, wherein plate-like formations of the discs 5c form spaces 5e, which are traversed by the gas flow with contact over the largest possible area. Such a stacked disk design may conveniently consist of molded sheet metal parts made of corrosion-resistant steel. In principle, the exchange means 5 can also be produced from aluminum. Basically the exchanger means 5 may also be integrally formed with the housing 1 in the same material.

Depending on the design of the exchange means, it can have ribs, turbulence inserts, embossed structures, such as fins, which are arranged on the coolant side and / or on the gas side, as required, in order to improve the exchange performance.

In the second embodiment according to FIG. 3, the same function and largely identical flow paths are present in principle as in the first exemplary embodiment. As an essential difference from the first embodiment, the housing according to FIG. 3 and FIG. 4 is produced by a die-casting method with at least two-part mold, in which a first demoulding side of the housing 1 is assigned to the guide of the coolant and a second demolding side of the guide of the gas flow assigned. The Entungsungsseite of the coolant is shown in Fig. 3 and the Entformungsseite of the gas stream is shown in Fig. 4. Both on the coolant side and on the gas side is on the housing 1 each have a cover part (not shown). The cover parts can by means of seals and z. B. screwed or sealed by means of surface soldering.

Due to the different construction of the first embodiment, the housing 1 of the second embodiment comprises a material integral integral intermediate bottom which extends parallel to the flow direction of the gas flow over the largest part of the housing 1 and the wall portion 1 a, since he on the one hand to the coolant and on the other hand, adjacent to the gas flow. This intermediate bottom 1a has an opening 17, by means of which coolant is guided from the coolant-carrying housing side (FIG. 3) to the modular exchange means 5. To the- This opening 17 is provided with a seal for sealing the gas flow against the coolant.

The supply of the coolant takes place via a feed pipe 18, which passes through the gas-side cover, that is, the lid placed on the view according to FIG. 4, and opens into the exchanger means 5. After flowing through the exchange means 5, the coolant enters through the opening 17 in the coolant-side space of the housing 1 a. The cover part assigned to the side according to FIG. 3 has a sufficient distance from the intermediate bottom 1a, so that the coolant can flow over the entire intermediate bottom in a planar manner. Likewise, it flows through the vertically extending in Fig. 3 space 1c between the wall sections 1a and 1b, so that the vertical partitions 1a between coolant and gas stream are cooled. Similar to the first exemplary embodiment, a shaft-like cavity 1d is provided, which is arranged in the vicinity of the feed and discharge 3, 4 of the gas flow on the outer wall 1b. As in the first exemplary embodiment, the coolant is led away from this shaft 1d by a discharge nozzle.

The housing 1 of the second embodiment may also consist of a sheet metal part, in particular of stainless steel in a modification. The sheet can be deformed for example by simple deep drawing. The ratios of the depths of the structures to the height and width of the housing can be adjusted accordingly to enable deep drawing.

A further exemplary embodiment is shown in FIGS. 5 to 10. This has in common with the exemplary embodiment according to FIGS. 3 and 4 that the housing 1 is produced in a casting process with a gas-side demoulding side (see FIG. 8) and a Coolant side demolding page (see view of FIG. 9) is produced. Both gas side and coolant side a lid is arranged on the housing 1. The gas-side cover 2 consists, as in the first embodiment, of three plate elements 2a, 2b, 2c. The upper plate member 2a has a supply port 18 for the coolant. The feed pipe 18 leads into the modularly formed Tau- shear means 5, which is fixed to the cover part 2.

An outlet of the coolant from the exchanger means 5 leads through openings 20 of the bottom plate member 2 c of the lid 2 in channel-like openings 19 of the central plate member 2 b. Due to the flow through the channels 19 (only a short channel is shown by way of example in FIG. 6), the cover part 2 is cooled. About openings 20 in the lower plate member 2 c, the cooling center Istrom is then continued into the housing 1, where it flows through to cool the wall sections 1 a, 1 b between these cavities 1 c.

As a further embodiment, a valve member 21 for controlling the gas flow is arranged in the housing 1 of the embodiment of FIG. 5 to FIG. 10 by means of suitable openings. The valve member 21 comprises a valve spool 22 and a slide rod 23 which is guided in a gastight manner through the wall 1b and which is connected to a drive M exemplified in FIG.

The valve member 21 may be received by means of steel, ceramic or other inserts in the aluminum housing.

The valve spool is in the schematic representation of an elongated cylinder, which passes through in a middle position two openings of two wall sections 24, 25. In this middle position (see Fig. 8), the passage for the gas flow is completely blocked, which can either take a path through the wall 24 and subsequently through the exchanger means 5 or through the wall 25 and directly to the gas outlet 4. Depending on the movement of the Slider 22 from its central position in one direction or the other, both size and course of the gas flow can be adjusted. The direct route from the inlet 3 to the outlet 4 through the wall 25 is a bypass operation in which the gas flow does not undergo any appreciable cooling.

A further advantageous detail of the embodiment according to FIGS. 5 to 10 results from the sectional view according to FIG. 10. A separating web 26 between the incoming and returning gas flow has a cavity on the coolant side corresponding to the construction of the housing 1. On a coolant-side cover 27 deflection webs 27a are formed, which protrude into this cavity. As a result, the coolant according to FIG. 10 experiences a multiple deflection in the cavity 26, so that the gas-side separating web 26 is cooled particularly well.

Since the coolant-side cover member 27 has no direct contact with the gas to be cooled, it may in principle be made of plastic even in the case of hot gases. However, it may also be an aluminum cover part, which is mechanically fixed or glued over seals in the previously described manner or surface-soldered.

The flow paths of the coolant may be different in the embodiments according to FIGS. 1 to 10, depending on the arrangement of the feeding, discharging and distributing channels. It can first flow through the exchanger means and subsequently the housing or vice versa. Alternatively or additionally, a flow branch can be provided, by means of which a partial flow flows through the exchanger means and another partial flow through the channels for housing and lid cooling.

Another embodiment of the invention is shown in FIG. In contrast to the exemplary embodiments according to FIGS. 1 to 10, it is This is not a U-flow heat exchanger, but an I-flow heat exchanger in which the gas flow through the heat exchanger in the longitudinal direction and the feed pipe 3 is arranged with respect to the housing 1 on the opposite side of the discharge nozzle 4.

The housing 1 of the heat exchanger according to FIG. 12 and FIG. 13 is designed as an extruded profile of an aluminum alloy which is of integral material. The extruded profile 1 comprises a central continuous chamber 28 for guiding the gas flow, which is enclosed by a wall portion 1 a substantially circular. From the first wall portion 1a, rib members 29 extend into the chamber 28 to enlarge the wall surface to improve heat exchange. The first wall section 1 a is surrounded concentrically by a second wall section 1 b, which forms an outer wall of the housing 1. A number of connecting webs 30 connect the first wall section 1a to the second wall section 1b. Between the first wall portion 1 a and the second wall portion 1 b, a plurality of passage channels 31 are arranged for the passage of the coolant. The wall portion 1 b thus separates the coolant from the environment and the wall portion 1 a, which is formed integrally with the wall portion 1 b of the same material, separates the gas flow from the coolant. According to FIG. 12, an inlet-side connection region 32 and an outlet-side connection region 33 are arranged at each end of the housing 1.

The terminal areas 32, 33 are glued to the housing 1 or soldered under exclusive local heating. A screw connection in conjunction with sealants is possible. It is important that the extruded profile 1 is no longer completely heated during assembly, since investigations have shown that extruded aluminum has a particularly good corrosion resistance to hot exhaust gases. This surprising effect could by the temperature and pressure conditions of the EP2007 / 006237

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Extrusions emerging crystal structure of the material can be explained. Important for a good function with respect to the corrosion resistance of the aluminum of the housing 1 is that no excessive heating is made in the course of the production of the entire device more.

A further advantage of the embodiment according to FIGS. 12 and 13 results from the fact that the tubular elongate housing 1 can be bent to adapt to the available installation space.

A modification of the embodiment of FIGS. 12 and 13 is shown in FIG. 14. Shown is a cross section through a modified housing 1. The modified housing is not round in cross-sectional shape, but substantially rectangular. Between an outer wall portion 1 b and an inner wall portion 1 a coolant channels 31 are formed. The first wall section 1a surrounds a gas channel 28, which is provided with fin elements 29 projecting from the wall 1a for the purpose of better cooling. Adjacent to the gas channel 28, a gas channel formed by the bypass channel 34 in the extrusion pressprofi I is provided. In the present example, the bypass channel 34 has a Innenverklei- düng of a stainless steel sheet 35 for better thermal insulation, since the flow of the bypass channel as low as possible cooling of the exhaust gas is desired.

15 shows a further embodiment of a device for cooling a gas stream 60 of an internal combustion engine 50 according to a second variant of the invention in a schematic form, as for example - in adapted version - similar to that shown in Fig. 17, in the context of a suction module 40th for an internal combustion engine 50 can be realized.

Basically, the operation of the module shown in FIG. 15 corresponds to that of a module as shown in FIG. 1, FIG. 4 or FIG. Especially 4, similar to the module shown in FIG. 4, also in the module shown in FIG. 15, the exchanger means 5 designed as a cooler is operated in a U-flow arrangement.

Both FIG. 15 and FIG. 16 show only a gas-side demolding side of the housing 1, in a similar manner as is the case in FIGS. 1, 4 and 8. FIG. 16 shows, with otherwise identical mode of operation, the arrangement of an exchanger means 5 embodied as a cooler in the module in an I-flow arrangement. In addition, a bypass 34 is realized, which can be shielded by the exchange means 5 by a partition wall 1e 'optionally provided in FIG. 16. Otherwise, parts with the same function are provided with the same reference numerals in FIGS. 15 to 17 and symbolizes coolant flows with dotted arrows and gas flows with solid arrows, as already explained in the embodiments explained above.

In particular, the coolant is transferred to the housing via the cover between the opening 17 and the channel 1d. The coolant transfer for the inner region 1b 'from the inside to the outside takes place on the coolant side, which is arranged on the underside of the housing in the embodiment shown in FIGS. 15 and 16.

The previously explained embodiments according to the first variant of the invention provide that the first wall section 1a and in particular also the second wall section 1b of the housing 1 or of a housing part is designed as a cooled wall section. In contrast thereto, the exemplary embodiments explained in connection with FIGS. 15 and 16 according to the second variant of the invention provide that only a part of the outer housing wall is cooled by coolant and practically only those wall areas which also come into contact with comparatively hot exhaust gas kick, be cooled. Accordingly, in the exemplary embodiments shown in FIGS. 15 and 16, the second wall section 1 b forms only in one embodiment. In the first sub-area, namely in the partial area shown in dashed lines, except for areas of the feed 3 and 4 discharge of the gas to be cooled 60, a housing outer wall of a housing part and / or a housing 1. The portion shown in dashed lines in FIG. 15 and FIG is substantially limited to those areas of the housing part and / or the housing 1, which are in contact with the comparatively hot and uncooled gas. In the present case, this is the case in the entry area on the right-hand side shown in FIGS. 15 and 16 and / or in the bypass area on the left-hand side of the housing part 1 and / or the housing 1 shown in FIGS. 15 and 16. For this purpose, moreover, a section 1b 'of the second wall section 1b is arranged inside the housing.

Both in the realized in U-flow design module of FIG. 15 and in the realized in I-flow design module of FIG. 16 is according to the second variant of the invention, the housing - or the presently shown gas-side housing section - with a third uncooled wall portion 1e provided, which forms a housing outer wall of the presently shown gas-side housing part or of the housing 1 in a further, second, unmarked portion shown. As can be seen in FIGS. 15 and 16, the second subregion is restricted to those regions of the housing part which are in contact with comparatively cooler gas or cooled and / or partially cooled gas - for example the deflection region 7 or regions which are adjacent to Exchange means 5 are. On the other hand, an area adjacent to the bypass, as shown in Fig. 16, is provided with a second wall portion 1b as a portion to be cooled. The second wall section 1b and the third wall section 1e together form virtually completely a housing outer wall of the gas side housing part shown here - or in the case of analogy to FIG. 1, the housing 1. The optional partition wall shown in FIG. 16 is thus a housing-internal section 1e 'of the third wall portion 1e executed. It has been shown that in the embodiments shown in FIGS. 15 and 16 according to the second variant of the invention, without any further increase in weight, the cooled wall regions-that is to say the dashed wall sections 1 b-can be designed with a significantly increased wall thickness as the uncooled wall areas - namely the areas of the third wall portion 1e. In addition, the further embodiment of embodiments, not shown here allows the design of a cooled wall portion 1 b, in contrast to an uncooled wall portion 1 e in a particularly suitable manner for use.

FIG. 17 shows an exemplary possibility of how a module realized in I-flow design-for example a module of FIG. 16 -can be integrated into an intake module 40. For this purpose, an exhaust gas flow recirculated from the engine 60 is fed to the module via a gas feed 3 and continued there, as described in the previously described embodiments of the first and second variants. In the present case, in turn, the double-walled or thick-walled wall sections 1b are designed with dashed lines. In the context of the embodiment shown in FIG. 17, these are practically all wall sections lying on the outside of the housing. Nevertheless, according to the concept of the second variant of the invention, a section 1e shown in FIG. 16 as a third wall section-referred to as wall section 1b in FIG. 17-has a thinner wall than the second wall section 1b. This makes it clear that, as part of a teaching mediating between the first variant and the second variant of the invention, a wall section 1eb can be designed for comparatively less complex cooling in comparison to a second wall section 1b. Nevertheless, a wall section 1eb is a wall section cooled in comparison to the non-cooled third wall section 1e. In the intake module 40 shown in FIG. 17, moreover, a coolant-cooled charge air cooler 51 is arranged in the lower region, which can be supplied with charge air via a throttle flap 52 and coolant can be supplied and removed via a supply 58 or an exhaust 56.

Similarly as in FIG. 8, in the embodiments shown in FIGS. 15 and 16, a cylindrical slide 22 is realized, which can be activated via a slide rod 23 and a drive M, so that the gas either via a bypass path 1 or a cooling path 2 is passed.

It is understood that the individual features of the various described embodiments can be usefully combined depending on the requirements.

Claims

Patent claims

A device for cooling a gas flow (60) of an internal combustion engine (50), comprising a housing (1) having a first wall portion (1 a) and a second wall portion (1 b); a feed (3) and a discharge (4) for a gas to be cooled, in particular exhaust gas and / or charge air of the internal combustion engine; a supply (18) and a discharge (16) for a particular liquid coolant; an exchanger means (5) for transferring heat between the gas and the refrigerant; wherein the first wall portion (1a) between the coolant and the

Gas flow is arranged and the second wall portion (1 b) between the coolant and an environment, in particular the atmosphere, is arranged; characterized in that the first wall portion (1a) and the second wall portion (1 b) are integrally formed of the same material.

2. Apparatus according to claim 1, characterized in that the first and the second wall portion (1a, 1b) of the housing (1) made of a light metal, in particular based on aluminum exist.

3. Apparatus according to claim 1 or 2, characterized in that one of the first and the second wall portion (1 a, 1 b) more comprehensive Housing part (1) as a casting, in particular die-cast part, is formed.

4. Apparatus according to claim 3, characterized in that the housing part (1) has a first demolding side and a second demoulding side, wherein the first demolding side is designed to guide the coolant and the second demoulding side to guide the gas.

5. Apparatus according to claim 1 or 2, characterized in that a the first and the second wall portion (1a, 1b) comprising housing part (1) is designed as an extruded profile.

6. The device according to claim 1, characterized in that the first and the second wall portion (1 a, 1 b) of the housing (1) consists of a

Sheet metal part, in particular of a stainless steel are formed.

7. Apparatus according to claim 6, characterized in that the sheet metal part is a deep-drawn part.

8. Device according to one of the preceding claims, characterized in that the housing (1) comprises at least one non-integrally formed with the wall sections lid part (2, 10).

9. Apparatus according to claim 8, characterized in that on the cover part (2, 10) sealing means are provided for sealing the coolant and / or the gas.

10. The device according to claim 8, characterized in that the cover part (2, 10) with the further housing (1) is sealingly soldered.

11. Device according to one of claims 8 to 10, characterized in that at least one of the two, the supply (18) or the discharge (16) of the coolant, on the cover part (2, 10) is arranged.

12. Device according to one of claims 8 to 11, characterized in that in the cover part (2, 20) has a channel (12, 13, 14, 19) is arranged to guide the coolant.

13. The apparatus according to claim 12, characterized in that the cover part (2, 10) at least two superposed plate-like elements (2a, 2b, 2c), wherein the channel (12, 13, 14, 19) through a recess in at least one of the plate-like EIe- elements (2b) is formed.

14. Device according to one of claims 12 or 13, characterized in that the cover part (2) has an overflow opening (20) for connecting the channel (12, 13, 14, 19) with the further housing (1).

15. Device according to one of claims 8 to 14, characterized in that the exchanger means (5) is formed as with the cover part (2) connected module.

16. Device according to one of the preceding claims, characterized in that the exchanger means (5) as a stack of discs (5c) is formed, in particular, the stack can be flowed through by the coolant and the gas flow around.

17. Device according to one of claims 1 to 15, characterized in that the exchanger means (5) with a plurality of cooling ribs (29) is formed.

18. The apparatus according to claim 17, characterized in that the exchanger means (5) is formed as a cast part, in particular die-cast part.

19. The apparatus according to claim 17, characterized in that the exchanger means (5) is formed as an extruded part.

20. Device according to one of claims 1 to 19, characterized in that the exchanger means (5) comprises a tube bundle.

21. Device according to one of the preceding claims, characterized in that the exchange means (5) is designed as arranged in the housing module.

22. Device according to one of claims 1 to 20, characterized in that the exchanger means of the same material integral with the first and the second wall portion (1 a, 1 b) is formed.

23. Device according to claim 22, characterized in that the exchange means has a plurality of material which can be flowed through by the gas and formed in a material integral with the first wall section

Includes radiator fins (29).

24. Device according to one of the preceding claims, designed as a U-flow cooler.

25. Device according to one of claims 1 to 23, formed as an I-flow cooler.

26. Device according to claim 25, characterized by a bypass channel (34).

27. Device according to one of the preceding claims, characterized in that in the housing (1) a valve member (21) is arranged for adjustable deflection of the gas stream.

28. Device according to one of the preceding claims, characterized in that in the housing (1) a valve member (21) is arranged for adjustably controlling a total size of the gas stream.

29. The device according to claim 28, characterized in that via the valve member (21) also a deflection of the gas flow through the exchanger means or a bypass path is adjustable.

30. Device according to one of claims 1 to 29, characterized in that the first wall portion (1 a) and / or the second wall portion (1 b) is a cooled wall portion.

31. Device according to one of claims 1 to 30, characterized in that the first wall portion (1 a), in particular completely, is arranged housing interior.

32. Device according to one of claims 1 to 31, characterized in that the second wall portion (1 b) practically completely, in particular completely to areas of the feed (3) and the Outlet (4) of the gas to be cooled, a housing outer wall of a housing part and / or a housing (1).

33. Device according to one of claims 1 to 31, characterized in that the second wall section (1 b) only in a first

Subarea, in particular only in a first portion except for areas of the feed (3) and discharge (4) of the gas to be cooled, a housing outer wall of a housing part and / or a housing (1).

34. Device according to one of claims 1 to 33, characterized in that a first portion is substantially limited to those areas of a housing part and / or housing (1), which are in contact with relatively hot, especially non-cooled, gas, is limited in particular to input and / or bypass areas of a housing part and / or a housing (1).

35. The device according to one of claims 1 to 34, characterized in that a section of the second wall section (1b) is disposed on the inside of the housing.

36. Device according to one of claims 1 to 35, characterized in that the housing (1) has a further third wall portion (1e).

37. Device according to one of claims 1 to 36, characterized in that the first wall portion (1 a) and the second wall portion (1b) and the third wall portion (1e) are integrally formed of the same material.

38. Device according to one of claims 1 to 37, characterized in that the third wall portion (1e) is uncooled.

39. Device according to one of claims 1 to 38, characterized in that the third wall portion (1e) forms in a further second portion a housing outer wall of a housing part and / or a housing (1).

40. Device according to one of claims 1 to 39, characterized in that a second portion is substantially limited to those areas of a housing part and / or a housing (1) which in contact with relatively cooler gas, in particular cooled and / or part-cooled gas, are, in particular limited to the exchanger means (5) adjacent areas and / or deflection regions (7) of a housing part and / or a

Housing (1).

41. Device according to one of claims 1 to 40, characterized in that the second wall portion (1b) and the third wall portion (1e) together practically completely, in particular completely to the area of the feed (3) and discharge (4) of to be cooled gas, a housing wall of a housing part and / or a housing (1) form.

42. Device according to one of claims 1 to 41, characterized in that a portion of the third wall portion (1e) is arranged housnennenliegend.

43. Device according to one of claims 1 to 42, characterized in that the third wall portion (1e) is made thin-walled than the second wall portion (1b), in particular with a Wall thickness which corresponds approximately to the wall thickness of the first wall portion (1 a).

44. Device according to one of the preceding claims, character- ized in that the housing (1) is part of an intake module (40) of the internal combustion engine (50).

45. Exhaust gas recirculation system for an internal combustion engine, comprising an exhaust gas recirculation, a compressor and characterized by a device according to one of claims 1 to 44 in the form of a

Exhaust heat exchanger, in particular -Kühlers.

46. Charge air supply system for an internal combustion engine, comprising a charge air intake, an air filter, a compressor and characterized by a device according to one of claims 1 to 44 in the form of a charge air heat exchanger, in particular -Bühlers.

47. Use of the device according to one of claims 1 to 44 as an exhaust gas cooler for the direct or indirect cooling of exhaust gas in one

Exhaust gas recirculation system for an internal combustion engine of a motor vehicle.

48. Use of the device, in particular of the exhaust gas cooler, according to one of claims 1 to 44 as a heater for the interior heating of a motor vehicle.

49. Use of the device according to one of claims 1 to 44 as a charge air cooler for direct or indirect cooling of charge air in a charge air supply system for an internal combustion engine of a motor vehicle.

50. Use of the device according to one of claims 1 to 44 as an evaporator, in particular for guiding a designed as a vaporizable medium coolant.

51. Use of the device according to one of claims 1 to 44 as a condenser, in particular for guiding a designed as a condensable medium gas stream.

52. Use of the device according to one of claims 1 to 44 as an oil cooler, in particular for cooling engine oil and / or gear oil.

53. Use of the device according to one of claims 1 to 44 refrigerant cooler or refrigerant condenser in a refrigerant circuit of an air conditioner of a motor vehicle.