CN117889688A

CN117889688A - Heat exchanger

Info

Publication number: CN117889688A
Application number: CN202311196982.1A
Authority: CN
Inventors: 西蒙·洪德
Original assignee: Mahle International GmbH
Current assignee: Mahle International GmbH
Priority date: 2022-10-14
Filing date: 2023-09-15
Publication date: 2024-04-16
Also published as: DE102022210887A1

Abstract

The invention relates to a heat exchanger, comprising a tubular housing, comprising two bottoms and a flat tube, which extends through the housing and is held in each case at the longitudinal end in a slot-shaped through opening in the bottom, wherein a first flow channel is formed in the flat tube and a second flow channel is formed between the flat tube and the housing, wherein the housing is formed from two respectively integrated and pot-shaped housing parts, each of which has a housing section, a flange ring section and a bottomAnd wherein the two housing parts can be connected to each other by means of two flange ring sections. In this case, according to the invention, the web height d between two adjacent through-openings _S Less than 1.5mm. This allows higher cooling performance and can be used in gasoline engines.

Description

Heat exchanger

Technical Field

The invention relates to a heat exchanger with a tubular housing, a flange ring, two bottoms and flat tubes according to the preamble of claim 1. The invention also relates to an internal combustion engine with such a heat exchanger.

Background

A heat exchanger of this type is known from DE 10 2014 225 159 A1, which has a tubular housing, two bottoms and flat tubes which extend through the housing and are each held at the longitudinal end side in a slot-shaped through opening in the bottom. A first flow channel is formed in the flat tube and a second flow channel is formed between the flat tube and the housing. The housing is formed by two respectively integral and pot-shaped housing parts.

Another heat exchanger is known from DE 10 2012 211 311 A1.

However, the heat exchangers known from the prior art have the disadvantage that their efficiency is limited by the minimum distance to be maintained between two adjacent flat tubes of the heat exchanger in terms of manufacturing technology, so that the heat exchangers known from the prior art can generally only be used for diesel internal combustion engines, but not for gasoline engines.

Disclosure of Invention

The object of the present invention is therefore to specify a better or at least one alternative embodiment for a heat exchanger of this type, which is distinguished in particular by higher performance.

This object is achieved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

The general idea underlying the present invention is to modify the heat exchangers known so far in such a way that they have significantly higher performance, in particular cooling performance, and are therefore also suitable for use in high-power gasoline engines. The higher efficiency is hereby facilitated by the flat tubes being more closely spaced from one another, and thus also a higher flow speed of the cooling medium and thus better cooling performance. The heat exchanger according to the invention has a tubular housing and has two opposite bottoms and flat tubes arranged between them, which extend through the housing and are each held at the longitudinal end side in a slot-shaped through opening in the bottom. The flat tube is in this case inserted in a form-fitting manner into the through-opening of the base and is usually soldered therein. In this case, a first flow duct, for example for exhaust gas, extends in the flat tube and is used, for example, for coolingA second flow path for the medium extends between the flat tube and the housing. The housing is formed from two respectively one-piece and pot-shaped housing parts, each of which has a housing section, a flange ring section and a bottom, and wherein the two housing parts are connected to one another or can be connected to one another by means of the two flange ring sections. A tab is arranged between the individual through openings in the respective bottoms, wherein according to the invention, a tab height d between two adjacent through openings is provided _S Less than 1.5mm.1.5mm represents the minimum tab height that can be produced safely in the process to date, wherein the tab height d is reduced according to the invention _S The flow cross section for the second flow channel remaining between the individual flat tubes can be reduced and thus the flow speed of the cooling medium can be increased there, so that the efficiency of the heat exchanger can be increased. The heat exchanger according to the invention is also suitable for the first time for a gasoline engine, that is to say a gasoline engine, by virtue of its higher efficiency.

In an advantageous embodiment of the heat exchanger according to the invention, the web height d _S Between 1.0mm and 1.3 mm. Here, 1.0mm represents the target value, which makes it possible to continue to significantly reduce the cross section of the second flow channel between the individual flat tubes and furthermore to significantly increase the flow speed there, compared to 1.5mm and even compared to 1.3 mm.

In experiments it has been shown that such thin webs can be produced, which has hitherto been considered impossible. Furthermore, it is now also possible to use gasoline engines at temperatures up to 1100 ℃.

The flat tube suitably has a height d of between 3.0mm and 3.5mm, in particular about 3.2mm _F And a width b of between 13.0mm and 14.0mm, in particular about 13.75mm _F . Hitherto, flat tubes having a cross-sectional area of 13.5mm x 4.0mm have been used in heat exchangers known from the prior art, so that with flat tubes constructed according to the invention a reduction in the cross-sectional area of the flat tubes can be achieved, whereby more flat tubes can be arranged and thus the efficiency of the heat exchanger can be increased. In this case, it is particularly advantageous if, with regard to the flow cross section of the respective flat tube, one can mentionFor a significantly larger surface for heat exchange, whereby the cooling performance is also improved.

The heat exchanger is suitably at least partially constructed of stainless steel. The solution of the heat exchanger consisting of stainless steel offers the great advantage that the heat exchanger is resistant to both corrosion and aggressive exhaust gases, especially when used as an exhaust gas heat exchanger. The service life of the heat exchanger can thus be significantly prolonged in particular.

In a further advantageous embodiment of the heat exchanger according to the invention, a filter device is provided having a filter element and an annular edge, wherein the annular edge rests against a housing section of the associated housing part and the filter element covers the through opening. The filter element is in this case configured round, wherein the annular edge protrudes substantially perpendicularly to the filter element and thus a design of the filter device is achieved which enables a simple displacement of the filter device onto the bottom of the respective housing part or onto the housing section. In particular, simple assembly and disassembly are thereby also achieved.

In a particularly preferred embodiment, at least one access panel extending in the circumferential direction is arranged at the annular edge of the filter device, which access panel has a beveled edge at the free end and an opening coupled to the beveled edge. At least one projection, for example a bead-like projection, is provided on the housing section of the housing part, which engages in an associated opening of the carrier plate when the filter device is mounted on the housing part. It is thus possible, for example, to create a positive connection between the filter device and the housing part, which not only enables the filter device to be reliably fastened to the housing part, but also enables the filter device to be relatively simply assembled and disassembled from the housing part. The oblique side can be embodied as a beak, wherein the assembly of the filter device on the respective housing part can preferably be carried out such that the filter device is first pushed onto the housing part in the axial direction until the filter element rests on the bottom of the associated housing part. The rotational angle of the filter device relative to the housing part is selected such that the projection on the housing part reaches the height of the beak-shaped oblique edge in the axial direction at the free end of the associated attachment plate. The filter device is then rotated relative to the housing part and the lug is thus moved with a sloping edge over the projection until the projection engages in the opening of the lug and the lug springs back into the housing section of the housing part. The projections on the housing part side engage in openings in the respective webs, preferably in a form-fitting manner, and thereby fix the filter device to the housing part. If the filter device should be released again from the housing part, at least one access panel first has to be lifted outwards in order to move the opening over the projection and to rotate the filter device relative to the housing part or to pull the filter device out of the housing part. The attachment plate together with the openings and the projections on the housing part side enable a relatively simple and reliable fastening of the filter device at the housing part.

In a particularly preferred embodiment of the heat exchanger according to the invention, at least one positioning contour is arranged at the bottom. Such positioning contours can be configured in the form of a granulated pattern of projections or recesses and are used for orientation during modular production. Rotation is thereby prevented, so that the flat tube can be safely introduced into the correspondingly punched through-opening at the bottom.

Suitably, at least one of the housing parts is configured as a modified sheet metal stamping and is produced in particular by deep drawing. In addition to avoiding joints, the individual housing parts should of course also be able to be produced with high quality and at a low cost, which can be achieved in particular by producing the housing parts as modified sheet metal stampings. The pot-shaped design of the respective housing part can be achieved in this case, in particular, by deep drawing.

In an advantageous embodiment of the heat exchanger according to the invention, the two housing parts are fixed to one another by means of a snap connection. Such a snap connection enables a faster assembly of the two housing parts to each other and also a simpler release of the two housing parts from each other, in particular, for example, compared to a screw connection. The latching elements forming the snap connection can be formed in one piece with the respective flange ring section of the housing part and can thus be produced simply and cost-effectively in terms of production technology.

At least one of the snap elements expediently protrudes in the axial direction from the associated flange ring section and forms an anti-rotation part, which in turn forces the heat exchanger to be mounted in an anti-rotation manner and in terms of the installation position specifically on, for example, an internal combustion engine. Such an anti-rotation means thus prevents an undesired rotation of the respective housing part, whereby, for example, condensate can be reliably discharged from the heat exchanger.

Further important features and advantages of the invention result from the dependent claims, from the drawing and from the attached drawing description by means of the drawing.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respective described combination but also in other combinations or alone without departing from the scope of the invention. The components of the superordinate unit, such as the devices, apparatuses or installations, mentioned here and in the following, may form individual components or parts of the unit or may be integral regions or sections of the unit, even if this is not shown separately in the figures.

Drawings

Preferred embodiments of the present invention are illustrated in the accompanying drawings and described in the following detailed description, wherein like reference numerals refer to identical or similar or functionally identical components. Wherein:

fig. 1 schematically shows a perspective view of a heat exchanger according to the invention;

FIG. 2 schematically illustrates a front view of the bottom of a heat exchanger;

fig. 3 shows a schematic view of a heat exchanger according to the invention without a filter device;

fig. 4 shows a schematic view of a heat exchanger according to the invention with a filter device arranged thereon;

fig. 5 shows a schematic detail of the heat exchanger in the region of the snap connection between the filter device and the associated housing section of the heat exchanger.

Detailed Description

According to fig. 1 and 4, a heat exchanger 1 according to the invention, which can be configured, for example, as an exhaust gas heat exchanger, has a tubular housing 2 with a flange ring 3 and two bottoms 4 and flat tubes 5, which extend through the housing 2 and are each held at the longitudinal end in a slot-shaped through opening in the bottom 4. The first flow channel extends in the flat tube 5, while the second flow channel is formed between the flat tube 5 and the housing 2.

The housing 2 is composed of two housing parts 7, 8, each of which has a housing section 9, a flange ring section 10 and a base 4, which are each of one-piece and can-shaped construction, and the two housing parts 7, 8 can be connected to one another by or by means of the two flange ring sections 10. According to fig. 1 to 5, only one of the bottoms 4, here the bottom at the housing part 8, is illustrated in more detail here.

At the housing part 7, for the embodiment of the heat exchanger 1 according to the invention as an exhaust gas cooler, an exhaust gas outlet 11, a coolant inlet 12 and a coolant outlet 13 are provided. The exhaust gases enter here according to arrow 14, i.e. essentially in the axial direction of the housing 2.

Between the individual through openings 6, webs 15 (see in particular fig. 2) are arranged which space two adjacent flat tubes 5 arranged in the respective associated through opening 6 from one another. These webs 15 have heretofore generally been designed with a minimum web height d of greater than 1.5mm _S This is because these tabs cannot be made thinner in terms of manufacturing technology. According to the invention, the tab height d between two adjacent through openings 6 is now the same _S Less than 1.5mm, preferably even less than 1.3mm, the individual flat tubes 5 are therefore arranged closer together and the available flow cross section between two adjacent flat tubes 5 may in particular also be smaller. As a result of the smaller flow cross section, a higher coolant flow takes place in this region, so that the heat exchanger 1 according to the invention has a higher performance. In one placeIn a particularly preferred embodiment, the tab height d between two adjacent through openings 6 _S Only about 1mm, thus achieving a further performance improvement.

The heat exchanger 1 according to the invention can now also be used for the first time in gasoline engines, that is to say in gasoline engines, owing to the markedly improved cooling properties, which has not been possible until now.

The flat tubes 5 used in the heat exchanger 1 according to the invention furthermore have a height d of between 3.0mm and 3.5mm, in particular about 3.2mm _F And a width b of between 13.0mm and 14.0mm, in particular about 13.75mm _F These flat tubes therefore have a height d of about 4.0mm compared to those used in heat exchangers known from the prior art _F And a width b of about 13.5mm _F Has a significantly smaller internal flow cross section. The thickness or wall thickness of the flat tube is 0.2 mm-0.4 mm. By reducing the cross-section in the first flow channel, i.e. for the exhaust gas, significantly more surface is available for heat exchange with respect to the cross-sectional area of the first flow channel, so that the cooling performance of the heat exchanger 1 can likewise be improved.

The heat exchanger 1 is composed at least in part of stainless steel, which offers advantages in particular with regard to corrosion resistance and also with regard to corrosion-resistant exhaust gases.

At least one of the two housing parts 7, 8 is embodied here as a modified sheet metal stamping and is produced by deep drawing. This allows not only a simple production technique but also a high-quality and cost-effective production.

In case of examining fig. 4 and 5, it can be seen that a filter device 16 with a filter element 17 and an annular rim 18 is arranged on the housing part 8, wherein the annular rim 18 rests against the associated housing section 9 of the housing part 8 and the filter element 17 covers the through opening 6. Thereby, a filtration of the exhaust gas flow through the flat tube 5 is achieved.

At the annular edge 18 of the filter device 16, at least one access panel 20 extending in the circumferential direction 19 is provided, which has a beveled edge 21 at the free end of the access panel and an opening 22 (see in particular fig. 5) coupled to the beveled edge 21. At least one projection 23 is arranged on the housing section 9 of the housing part 8, which projection engages into an associated opening 22 of the attachment plate 20 when the filter device 16 is mounted on the housing part 8. In general, in the embodiment of the filter device 16 shown in fig. 4 and 5, a total of 4 support plates are provided.

The assembly of the filter device 16 on the housing part 8 of the heat exchanger 1 takes place here as follows:

the filter device 16 is first pushed in the axial direction (corresponding to arrow 14 in fig. 1) onto the housing section 9 of the housing part 8, in other words, the housing-part-side projections 23 are aligned in the axial direction with the recesses 24 at the edge 18 of the filter device 16. If the filter device 16 is pushed completely onto the housing section 9, the filter device 16 is rotated relative to the housing part 8, so that the individual webs 20 move with their oblique edges 21 over the housing-part-side projections 23. Upon further rotation, the projections 23 snap into or engage in the openings 22 of the carrier plate 20 and thereby securely fix the filter device 16 to the housing part 8. For disassembly, the access panel 22 must be lifted slightly outwardly in the radial direction so that the access panel 20 can be pulled over the projection 23.

In case of continuing to observe fig. 1 to 3, it can be seen that at least one positioning contour 25 is arranged at the bottom 4 shown there. According to fig. 1 to 3, a total of two positioning contours 25 in the form of nubbed recesses are provided for each base part 4. The positioning profile 25 facilitates the orientation during the modular production process, so that in particular the flat tube 5 can be safely introduced into the corresponding through opening 6 of the bottom 4.

Furthermore, the two housing parts 7, 8 can be connected to one another by a snap connection 26, wherein the snap connection 26 has at least one snap element 27 which protrudes in the axial direction from the associated flange ring section 10 of the associated housing part 7 and is of integral design with this flange ring section. The catch element 27 may be an anti-rotation feature in this case and thus facilitates the assembly of the heat exchanger 1, for example at the internal combustion engine 28. The catch element 27 furthermore prevents a possible rotation during operation, whereby it is ensured that condensate can flow out of the heat exchanger 1 in a process-safe manner over a long period of time and reliably.

With the heat exchanger 1 according to the invention, a significantly better cooling performance of the heat exchanger 1 can be achieved for the first time, so that such a heat exchanger can also be used for the first time in a gasoline engine.

Claims

1. A heat exchanger (1),

having a tubular housing (2),

having a flange ring (3) and having two bottoms (4) and a flat tube (5) which extends through the housing (2) and is held in each case at the longitudinal end in a slot-shaped through opening (6) in the bottom (4), wherein a first flow channel is formed in the flat tube (5) and a second flow channel is formed between the flat tube (5) and the housing (2),

wherein the housing (2) is formed from two respectively integrated and pot-shaped housing parts (7, 8), each of which housing parts (7, 8) has a housing section (9), a flange ring section (10) and a base (4), and wherein the two housing parts (7, 8) can be connected to one another by means of the two flange ring sections (10),

it is characterized in that the method comprises the steps of,

tab height d between two adjacent through openings (6) _S Less than 1.5mm.

2. A heat exchanger according to claim 1,

it is characterized in that the method comprises the steps of,

the tab height d _S The range of (2) is 1.0 mm.ltoreq.d _S ≤1.3mm。

3. A heat exchanger according to claim 1 or 2,

it is characterized in that the method comprises the steps of,

the flat tube (5) has a d range of 3.0mm < d- _F Height d less than or equal to 3.5mm _F And the sum range is 13.0 mm.ltoreq.b _F Width b of less than or equal to 14.0mm _F 。

4. A heat exchanger according to any one of claim 1 to 3,

it is characterized in that the method comprises the steps of,

-the heat exchanger (1) is at least partially made of stainless steel, and/or

-the heat exchanger (1) is configured as an exhaust gas heat exchanger.

5. The heat exchanger according to any one of claim 1 to 4,

it is characterized in that the method comprises the steps of,

at least one of the housing parts (7, 8) is designed as a modified sheet metal stamping and is produced by deep drawing.

6. The heat exchanger according to any one of claim 1 to 5,

it is characterized in that the method comprises the steps of,

a filter device (16) having a filter element (17) and an annular edge (18) is provided, wherein the annular edge (18) rests on a housing section (9) of the associated housing part (7, 8) and the filter element (17) covers the through-opening (6).

7. The heat exchanger according to claim 6,

it is characterized in that the method comprises the steps of,

at least one access panel (20) extending in the circumferential direction (19) is arranged at the annular edge (18) of the filter device (16), said access panel having a beveled edge (21) at the free end and an opening (22) coupled to the beveled edge (21),

-at least one projection (23) is arranged on the housing section (9) of the housing part (7, 8), which projection engages into an opening (22) of the associated access panel (20) when the filter device (16) is mounted on the housing part (7, 8).

8. The heat exchanger according to any one of claim 1 to 7,

it is characterized in that the method comprises the steps of,

at least one positioning contour (25) is arranged at the bottom (4).

9. The heat exchanger according to any one of claim 1 to 8,

it is characterized in that the method comprises the steps of,

the two housing parts (7, 8) are fixed to each other by means of a snap connection (26).

10. A heat exchanger according to claim 9,

it is characterized in that the method comprises the steps of,

the snap connection (26) has at least one snap element (27) which protrudes in the axial direction from and is formed integrally with the associated flange ring section (10) of the associated housing part (7, 8).

11. Internal combustion engine (28), in particular a gasoline engine, having a heat exchanger (1) according to any one of claims 1 to 10.

12. The internal combustion engine according to claim 11 with a heat exchanger according to claim 10, wherein the snap element (27) forms an anti-rotation part with the internal combustion engine (28).