EP2372286A2 - Heat exchanger - Google Patents

Abstract

The heat exchanger (1) has multiple housing parts (2,3), a base (4), multiple fluid-conducting fins and multiple fluid-conducting pipes (R). The fluid-conducting pipes are provided on an outer side with a knob-like elevated structure (9). One of the fluid-conducting pipes is formed as flat pipe with two narrow sides (5,6) and two broadsides (7,8).

Description

The invention relates to a heat exchanger for a motor vehicle according to the preamble of patent claim 1.

Such heat exchangers are used in internal combustion engines, for example as a charge air cooler or exhaust gas cooler. Various types are known in this area of application, for example tube bundle heat exchangers or plate heat exchangers.

For example, heat exchangers are known which consist of several parallel stacked plates. Each of the plates has on two opposite edges in each case an inlet and a discharge opening for a heat exchange medium. The plates form between each hollow chambers in which corrugated turbulence sheets (turbulence inserts) are provided to increase the heat transfer and which are flowed through by each one of the participating in the heat transfer media.

The turbulence inserts used are mainly required in the course of the manufacturing process and are not absolutely necessary for reasons of strength or thermodynamics. For example, it can during manufacture, it is necessary to clamp and position the tube-and-fin bundles, which is why the coolant channel required for the heat exchanger must be equipped with appropriate turbulence inserts (ribs, tubes or the like).

A disadvantage of the obstruction of such turbulence inserts, however, is that it comes, for example, to an increased cost of materials, unnecessary masses to be heated during soldering and increased tooling costs. Furthermore, there is a risk that geometric errors or inaccuracies of many items transferred and thus it comes to an enlarged tolerance chain.

The invention has for its object to provide a heat exchanger in which can be dispensed with the use of turbulence inserts,

This object is achieved by a heat exchanger having the features of claim 1.

The heat exchanger, which may include, for example, a plurality of housing parts, at least one bottom, a plurality of fluid-carrying ribs and a plurality of fluid-carrying tubes is characterized in that the fluidfuhrenden tubes are provided on at least one outer side with a knob-like raised structuring. By providing the knob-like raised structuring, the use of turbulence inserts can be dispensed with, since the structuring replaces the essential functions of the turbulence inserts. Another advantage is the fact that with constant or increased strength and performance, a reduction in the use of materials can be achieved. Also advantageous is the fact that by reducing the individual parts an improvement in terms of manufacturing tolerance chain can be achieved. A fluid in the sense of the invention means any gaseous or liquid medium. Within the meaning of the invention, the term heat exchanger also means a complete module, for example an exhaust gas module and / or intercooler.

One embodiment provides that the fluid-carrying tube can be formed as a flat tube with two narrow sides and two broad sides, wherein the knob-like structuring can extend substantially completely over the two broad sides. In essence, complete means that much of the broadside is provided with a knob-like raised structure. The tubes are thereby flowed around by a first medium and by a second medium, in the region of the knob-like structuring. For example, the first medium is gas and the second medium is a coolant. Thus, one medium may be gaseous while the other medium is liquid. For example, the gaseous fluid may at least partially consist of exhaust gas or charge air of an internal combustion engine, in which case the gaseous fluid is conducted inside the tube.

For example, it can be provided that the knob-like structuring runs regularly and / or irregularly on the broad sides. For example, even and irregular areas may be joined together, particularly to aid in the selective distribution of the coolant to critical, heat-stressed areas.

The nub-like structuring may consist of a plurality of individual raised nubs, extending from the surface of the broad side upwards. For example, the nubs may have a circular cross-section.

It is also conceivable that the nubs may have a substantially oval or elliptical cross-section.

Preferably, but by no means compulsorily, the nubs can have a substantially planar extending top surface, relative to the surface of the broad side of the tube, so that even contact surfaces result.

A preferred embodiment provides that the planar tops of the studs of two mutually juxtaposed tubes can abut each other in the composite, the studs on the one hand absorb the clamping forces during the joining process and on the other in the compound alley-like open spaces or channels are created, which can form the Kühlmttelkanal ,

One embodiment provides that the dimple height can be in the range of 0.2 mm to 1.5 mm, preferably 0.5 mm to 1 mm. These heights have proven to be particularly advantageous in the context of the present invention.

Another preferred embodiment provides that the tube width can be in the range of 30 mm to 100 mm, preferably 40 mm to 65 mm. These dimensions have proven to be particularly advantageous in the context of the present invention.

A further preferred embodiment provides that the tube height can be in the range of 3 mm to 12 mm, preferably 5 mm to 9 mm. These dimensions have also proven to be particularly advantageous in the context of the present invention. For example, the material thickness of the tube may be in the range of 0.2 mm to 1 mm, preferably 0.4 mm to 0.8 mm.

For example, the tube may be made of sheet metal and formed as a longitudinally welded or as a folded nub tube. Furthermore, it can be provided to realize the knobs or the structuring by means of an internal high-pressure forming or via an inserted wedge tool, in which case an externally mounted die may be provided. When pulling pipes, in addition to the die, which determines the outer diameter, also a pipe located in the tool - for example, plug or mandrel - used to achieve a defined wall thickness.

Further advantages, features and details of the invention will become apparent from the following description in which an embodiment of the invention is described with reference to the drawings. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination.

Fig. 1

die perspektivische Darstellung eines erfindungsgemäßen Wärmetauschers;

Fig. 2

eine vergrößerte Schnittdarstellung des Wärmetauschers gem. Fig. 1;

Fig. 3

die Draufsicht auf ein mit Noppen versehenes Rohr des Warmetauschers gem. der Fig. 1 bis 2;

Fig. 4

eine Seitenansicht auf zwei Rohre im Verbund (Noppenrohrbündel):

Fig. 5

die Draufsicht auf ein mit Noppen versehenes Rohr eines Wärmetauschers zweiter Ausführungsform.

Show it:

Fig. 1

the perspective view of a heat exchanger according to the invention;

Fig. 2

an enlarged sectional view of the heat exchanger acc. Fig. 1 ;

Fig. 3

the top view of a provided with knobs tube of the heat exchanger acc. of the Fig. 1 to 2 ;

Fig. 4

a side view of two tubes in the composite (knob bundle):

Fig. 5

the top view of a nubbed tube of a heat exchanger of the second embodiment.

Fig. 1 shows a perspective view of a heat exchanger 1, here exhaust gas cooler. The heat exchanger comprises a plurality of housing parts 2, 3 and a bottom 4, In addition, the heat exchanger 1 comprises six gas-carrying individual tubes R are combined to form a tube bundle RB, wherein the tube bundle RB is held between the housing parts 2, 3.

Each tube R is formed as a flat tube and each comprises two narrow sides 5, 6 and two broad sides 7, 8 (same components bear the same reference numerals). On the broad sides 7 and 8, each tube R is provided with a knob-like raised structuring 9.

Fig. 2 shows the heat exchanger 1 in a side enlarged sectional view. the section line AA.

The tubes R have in their interior gas-guiding ribs GS. The six individual tubes R are in a composite against each other and thus form the tube bundle RB. The individual tubes R open with one end face in the bottom 4 and with the other end face on the housing parts. 2

The tubes R are formed substantially identical in terms of structuring and their dimensions. In particular, the distribution of the individual nubs N on the respective broad side 7, 8 is the same.

Fig. 3 shows in plan view a single tube R in a single view. The tube has a structured broad side 7, wherein the structuring 10 is formed by a plurality of individual nubs N.

The nubs N are raised and have a cross-sectionally substantially circular cross-section. The nubs N are distributed regularly (in terms of number and orientation) on the broadside 7.

Fig. 4 shows two individual tubes R of the tube bundle RB in an enlarged side view. The two individual tubes R are in conjunction with the knobs N together. For this reason, the nubs have straight planar planar contact surfaces K. The nubs N are designed to that in each case two nubs N meeting each other absorb the clamping forces during the joining process and at the same time the lane-like cooling channels KK are formed.

Fig. 5 shows a further embodiment of a tube R 'for a heat exchanger. The tube R 'is on both broad sides 7', 8 '(only 7' visible) with a knob-like raised structuring 9 'provided. The nub-like structuring 9 'is formed by a multiplicity of individual nubs N', which have a circular cross section, and by a multiplicity of individual nubs N ", which have a substantially oval cross section.

The nubs N 'are distributed regularly on the broad side 7, while the nubs N "run irregularly on the broad side 7' The irregular arrangement of the nubs N" causes the coolant passed around the nubs N 'and N "specifically to critical, For this purpose, the dimpled shape can thus be variably shaped without departing from the basic idea according to the invention: Adjacent tubes R 'have the same structuring in the composite in order to ensure a simple and secure installation of the individual tubes.

Claims (13)

Heat exchanger (1) for a motor vehicle, comprising a plurality of housing parts (2, 3), at least one bottom (4), a plurality of fluid-carrying ribs (GS) and a plurality of fluid-carrying tubes (R, R '), characterized in that the fluid-carrying tubes (R , R ') are provided on at least one outer side with a knob-like raised structuring (9, 9'). Heat exchanger according to claim 1, characterized in that the fluid-carrying tube (R, R ') as a flat tube with two narrow sides (5, 6) and two broad sides (7, 7', 8, 8 ') is formed, wherein the knob-like structuring (9, 9 ') extends substantially completely over the two broad sides (7, 7', 8, 8 '). Heat exchanger according to one of claims 1 or 2, characterized in that the knob-like structuring (9, 9 ') regularly and / or irregularly on the broad sides (7, 7', 8, 8 ') extends. Heat exchanger according to one of claims 1 to 3, characterized in that the nub-like structuring (9, 9 ') consists of a plurality of individual nubs (N, N', N "). Heat exchanger according to claim 4, characterized in that the nubs (N, N ', N ") have a substantially circular cross-section. Heat exchanger according to claim 4, characterized in that the nubs (N, N ', N ") have a substantially oval or elliptical cross-section. Heat exchanger according to claim 4, characterized in that the nubs (N, N ', N ") relative to the surface of the broad side (7, 7', 8, 8 ') of the tube (R, R') has a substantially planar running have flat top or contact surface (K). Heat exchanger according to claim 7, characterized in that the planar upper sides or contact surfaces (K) of the knobs (N, N ', N ") of two mutually juxtaposed tubes (R, R') in the composite abut each other. Heat exchanger according to one of claims 4 to 8, characterized in that the nub height (NH) in the range of 0.2 mm to 1, 5 mm, preferably 0.5 mm to 1 mm. Heat exchanger according to one of claims 1 to 9, characterized in that the tube width (RB) in the range of 30 mm to 100 mm, preferably 40 mm to 65 mm. Heat exchanger according to one of claims 1 to 10, characterized in that the tube height (RH) in the range of 3 mm to 12 mm, preferably 5 mm to 9 mm. Heat exchanger according to one of claims 1 to 11, characterized in that the material thickness of the tube in the range of 0.2 mm to 1 mm, preferably 0.4 mm to 0.8 mm. Heat exchanger according to one of claims 1 to 12, characterized in that the tube (R, R ') is made of a sheet and formed as a longitudinally welded or as a folded knobbed tube.

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