DE102018124574A1 - Finned heat exchanger - Google Patents

Abstract

The invention relates to a fin heat exchanger (1) for cooling hot gas, in particular exhaust gas heat exchanger for internal combustion engines, comprising a gas inlet (4) and a gas outlet (5) for a gas flow (2) in channels (18) formed by spaced apart fins, characterized in that that the channels (18) are wave-shaped by means of wave ribs (14) and have a wave amplitude (16) and a wavelength (15), the wave amplitude (16) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) increases and / or the wavelength (15) of the wavy channels (18) from the gas inlet (4) to the gas outlet (5) becomes smaller.

Description

The invention relates to a finned heat exchanger for cooling hot gas. Such heat exchangers are also referred to as gas-coolant coolers with a rib, the gas being cooled by a liquid coolant, such as a water-glycol mixture of a motor vehicle cooling circuit. A preferred area of use for such heat exchangers is in the field of exhaust gas cooling in internal combustion engines, in particular in motor vehicles.

In principle, a generic heat exchanger with the function of a hot gas cooler consists of gas flow paths and liquid flow paths, which are separated from one another by a diathermic wall. The gaseous hot medium flows in the gas flow paths and releases heat to the cooler liquid medium, the coolant.
The gas paths are realized with pipes or channels, whereby the channels can be formed from fins, sheet metal plates or other elements.

Mit: $$1/\left(\text{k}\times \text{A}\right)=\left(1/{\mathrm{\alpha }}_{\text{Gas}}\times {\text{A}}_{\text{Gas}}\right)+\left({\text{S}}_{\text{Wand}}\times {\text{A}}_{\text{Wand}}/{\mathrm{\lambda }}_{\text{Wand}}\right)+\left(1/{\mathrm{\alpha }}_{\text{Fl}\ddot{\text{u}}\text{s}}\times {\text{A}}_{\text{Fl}\ddot{\text{u}}\text{s}}\right),$$

wobei

A =

Oberfläche

S =

Dicke

λ =

Wärmeleitkoeffizient

α =

Wärmeübergangskoeffizient

Da der Wärmeübergangskoeffizient des Gases sehr viel kleiner ist als der Wärmeleitkoeffizient der Wand und der Wärmeübergangskoeffizient des Kühlmittels, stellt der Wärmeübergang des Gases an die Kanalwand den größten Widerstand in dieser Wärmeübertragungskette dar.
Ein effizienter Wärmeübertrager, auch hinsichtlich des Materialeinsatzes und der Kosten, würde sowohl auf der Gas- als auch auf der Flüssigkeitsseite den gleichen Wärmeübergang realisieren. Um dies näherungsweise zu erreichen wird beispielsweise auf der gasführenden Seite die wärmeübertragende Oberfläche durch Rippen vergrößert, so dass die Oberfläche auf der Gasseite durch die Rippen sehr viel größer als die wärmeübertragende Oberfläche auf der Flüssigkeitsseite des Wärmeübertragers ist.
Ein weiterer Effekt, mit dem die Wärmeübertragung auf der Gasseite verbessert werden kann, ist die Art der Strömung. Eine turbulente Strömung ist für die Wärmeübertragung besser geeignet als eine laminare Strömung. Je größer die Turbulenz im Gas ist, desto größer ist der Wärmeübergangskoeffizient des Gases. Die Turbulenz wiederum ist im Wesentlichen von der Strömungsgeschwindigkeit des Gasstromes und der lokalen, randnahen Strömung des Gasstromes abhängig. Die Strömung und damit die Turbulenz wird zum Beispiel durch die Kanalform der den Kanal bildenden Rippen beeinflusst. Mit dem Anstieg der Strömungsgeschwindigkeit erhöht sich jedoch auch der gasseitige Druckverlust beim Durchströmen des Wärmeübertragers.The heat transfer through a wall of gaseous or liquid media can be simplified as follows: $$\text{Q}*=\left({\text{T}}_{\text{gas}}-{\text{T}}_{\text{K}\ddot{\text{u}}\text{St.}}\right)\times \left(\text{k}\times \text{A}\right).$$

With: $$1/\left(\text{k}\times \text{A}\right)=\left(1/{\mathrm{\alpha }}_{\text{gas}}\times {\text{A}}_{\text{gas}}\right)+\left({\text{S}}_{\text{wall}}\times {\text{A}}_{\text{wall}}/{\mathrm{\lambda }}_{\text{wall}}\right)+\left(1/{\mathrm{\alpha }}_{\text{Fl}\ddot{\text{u}}\text{s}}\times {\text{A}}_{\text{Fl}\ddot{\text{u}}\text{s}}\right),$$

in which

A =

surface

S =

thickness

λ =

Thermal conductivity coefficient

α =

Heat transfer coefficient

Since the heat transfer coefficient of the gas is much smaller than the heat transfer coefficient of the wall and the heat transfer coefficient of the coolant, the heat transfer of the gas to the duct wall represents the greatest resistance in this heat transfer chain.
An efficient heat exchanger, also with regard to the use of materials and costs, would realize the same heat transfer on both the gas and the liquid side. In order to achieve this approximately, the heat-transferring surface is increased by ribs on the gas-carrying side, for example, so that the surface on the gas side by the ribs is very much larger than the heat-transferring surface on the liquid side of the heat exchanger.
Another effect that can be used to improve heat transfer on the gas side is the type of flow. A turbulent flow is more suitable for heat transfer than a laminar flow. The greater the turbulence in the gas, the greater the heat transfer coefficient of the gas. The turbulence in turn is essentially dependent on the flow rate of the gas flow and the local flow of the gas flow near the edge. The flow and thus the turbulence is influenced, for example, by the channel shape of the ribs forming the channel. However, with the increase in the flow velocity, the gas-side pressure loss when flowing through the heat exchanger also increases.

Finned heat exchangers are used in the prior art as exhaust gas heat exchangers, also called EGR coolers, for cooling or recooling exhaust gases. The exhaust gases are up to 950 ° C and are cooled down in the exhaust gas heat exchanger to a cooling water temperature of, for example, 95 ° C or correspondingly colder by the cooling water.

From the JP 2010-112201 A a finned heat exchanger emerges, which is designed as a U-flow exhaust gas heat exchanger with finned or fin packs. The lamellae are designed as lamella packs made of sheet metal and have flow elements that cause turbulence in the gas flow and have a large surface area to absorb the heat from the gas flow and to dissipate it via heat conduction to the bottom and top surfaces, via which the heat is transferred to the Coolant is transferred. Continues from the JP 2010-112201 A a reduction in the channel width of the channels with backflow.

After DE 102005007692 A1 a corrugated fin for a cooling system is known, a corrugated fin for a cooling system being formed from a corrugated band with curved sections and linear sections. The curve sections are bent in a narrow radius and the linear sections are aligned in a V-shape. To guide the flow through the shaft ribs, gills are formed on at least one side of the linear sections, the gill flanks of which are inclined along the extent of the linear sections with respect to the linear sections such that the gill flanks of the gills of adjacent linear sections are aligned parallel to one another. Thus, the corrugated fins do not form a closed channel, but generate a wave-shaped gas flow through the gills. This has the disadvantage that the gas flow is not defined transversely to the direction of flow and the heat transfer behavior cannot be optimally designed.

The object of the invention is to improve the heat transfer from the gas over the length of the cooler while at the same time optimizing the flow resistance.

The object is achieved by an object with the features of the independent claims. Further developments are specified in the dependent claims.

The object of the invention is achieved in particular by a finned heat exchanger for cooling hot gas, which can be used in particular as an exhaust gas heat exchanger for internal combustion engines. The finned heat exchanger has a gas inlet and a gas outlet. The gas flows in undulating channels formed by spaced-apart corrugated ribs. The waveform of the channels naturally have a wave amplitude and a wavelength. The wave fin heat exchanger is characterized in particular in that the wave amplitude of the wave-shaped channels increases from the gas inlet to the gas outlet. Rising in the sense of the terminology of the invention means that the amplitude of the waves increases. Alternatively or cumulatively, the object of the invention is also achieved in that the wavelength of the waves from the gas inlet to the gas outlet becomes smaller or shorter.

The object of the invention is further achieved in particular by a corrugated fin heat exchanger whose wave amplitude of the corrugated channels increases steadily from the gas inlet to the gas outlet. According to the present invention, a steady increase in the wave amplitude means that a subsequent amplitude of the wave-shaped channel is greater than the previous amplitude. The extent to which it grows is initially irrelevant.

The wave amplitude of the wave-shaped channels from the gas inlet to the gas outlet is preferably formed starting at 0.0 mm, ie without a shaft, up to a value of 2.5 mm. The range of the amplitude is particularly preferably 0.8 mm to 2.0 mm, with different boundary conditions of gas temperature and volume flow correspondingly leading to different optima.

As an alternative to the steady increase, the invention is preferably further developed in that the wave amplitude of the wave-shaped channels increases continuously from the gas inlet to the gas outlet. An inconsistent increase in the wave amplitude should be understood to mean that several adjacent wave amplitudes have the same size and form a wave group with the same amplitude, followed by a next wave group, which then has a larger amplitude. A step-like course of the amplitude is formed along the gas flow path.

Analogous to the constant and discontinuous course of the amplitude, the wavelength of the wave-shaped channels from the gas inlet to the gas outlet is preferably also continuously or discontinuously smaller, which is to be understood to mean that the wavelength continuously decreases from one neighboring wave with respect to the respective predecessor.

An alternative advantageous embodiment of the invention for the constant decrease in the wavelength consists in that the wavelength of the wave-shaped channels from the gas inlet to the gas outlet becomes inconsistently smaller, which should be understood analogously to the discontinuity of the change in the wave amplitude that several adjacent waves have the same length and form a group and the next adjacent group then has a uniform and a smaller wavelength compared to the previous group.

The wavelength of the wavy channels from the gas inlet to the gas outlet is preferably smaller from 20 mm to 5 mm.

A further advantageous embodiment of the invention consists in that the channel width of the wave-shaped channels from the gas inlet to the gas outlet is steadily narrowing.

The channel width of the corrugated channels from the gas inlet to the gas outlet advantageously becomes continuously smaller in a range from 5.0 mm to 1.5 mm.

The fin heat exchanger, which is referred to as a corrugated fin heat exchanger using corrugated fins, is particularly preferably designed as an I-flow-through heat exchanger with gas inlet and gas outlet on opposite sides of the heat exchanger. The flow path of the gas is not deflected with regard to the inlet and outlet and flows through the heat exchanger along an imaginary longitudinal or transverse axis.

As an alternative to the embodiment described above, the corrugated fin heat exchanger is designed as a U-flow heat exchanger with gas inlet and gas outlet on one side of the heat exchanger. When the inlet and outlet are arranged on the same side, the gas flow is deflected by 180 ° and the gas inlet and gas outlet are preferably adjacent to one another. This results in a forward flow, a deflection and a return flow from the gas inlet to the gas outlet.

The object of the invention is achieved by a method for producing a corrugated fin heat exchanger according to one of the embodiments described above, wherein a corrugated corrugated sheet is produced with the same channel widths and then the corrugated corrugated sheet is stretched across the width of the corrugated sheet in a stretched area transversely to the channel direction and compressed in one The area is compressed transversely to the channel direction in such a way that the channel width is enlarged in the stretched area and reduced in the compressed area. It should be emphasized that the channel width is constantly increasing and decreasing.

Finally, the advantages of the invention can be implemented in that a corrugated fin plate described and produced according to the preceding method is used in a U-corrugated corrugated fin heat exchanger.

• 1. An der Gaseintrittsseite des Kühlers findet ein sehr großer Wärmeeintrag aus dem Gas statt, da die Temperaturdifferenz zwischen Gas und Kühlmittel (T_Gas,ein-T_Kühl) sehr groß ist und der Wärmeübergangskoeffizient α_Gas,ein sehr groß ist. Aufgrund der hohen Gastemperatur weist das Gas zudem eine geringe Dichte auf, die zu einem großen Volumen führt und somit zu einer hohen Strömungsgeschwindigkeit. Dieser große Wärmeeintrag in Verbindung mit hohen Temperaturen führt zu dem Problem, die Wärme an das Kühlwasser abzuführen und innerhalb des Kühlwassers zu verteilen. Es besteht die Gefahr des Überhitzens und Abkochens des Kühlwassers. Des Weiteren wird das Material des Wärmeübertragers enorm thermisch beansprucht. Aufgrund der hohen Strömungsgeschwindigkeit ist in diesem Bereich der gasseitige Druckverlust hoch.
• 2. An der Gasauslassseite des Kühlers ist das Gas mittlerweile abgekühlt und es findet nur ein kleiner Wärmeeintrag aus dem Gas an das Kühlmittel statt, da die Temperaturdifferenz (T_Gas,ein-T_Kühl) sehr klein ist und der Wärmeübergangskoeffizient α_Gas,ein sehr klein ist. Aufgrund der geringen Gastemperatur weist das Gas nun eine hohe Dichte auf, die zu einem kleinen Volumen führt und somit zu einer geringen Strömungsgeschwindigkeit. Dies führt zu dem Problem, dass in der Durchströmungsrichtung die Wärmeübertragung immer geringer wird und somit der „hintere“ Bereich des Kühlers vor dem Gasaustritt nur sehr ineffizient genutzt wird.

The concept of the invention is based on the following considerations:

• 1. At the gas inlet side of the cooler, there is a very large heat input from the gas, since the temperature difference between gas and coolant (T _{gas, a} -T _cooling ) is very large and the heat transfer coefficient α _{gas, a} very large. Due to the high gas temperature, the gas also has a low density, which leads to a large volume and thus to a high flow rate. This large heat input in connection with high temperatures leads to the problem of dissipating the heat to the cooling water and distributing it within the cooling water. There is a risk of the cooling water overheating and boiling. Furthermore, the material of the heat exchanger is subjected to enormous thermal stress. Due to the high flow velocity, the gas-side pressure loss is high in this area.
• 2. At the gas outlet side of the cooler, the gas has cooled down and there is only a small heat input from the gas to the coolant, since the temperature difference (T _{gas, a} -T _cooling ) is very small and the heat transfer coefficient α _{gas, a} very is small. Due to the low gas temperature, the gas now has a high density, which leads to a small volume and thus to a low flow rate. This leads to the problem that the heat transfer becomes less and less in the direction of flow and the “rear” area of the cooler before the gas outlet is therefore used only very inefficiently.

• - Anpassung der gasseitigen Oberfläche, die durch die Anzahl der Rippen angepasst wird und
• - Erhöhung der Turbulenz durch Veränderung der Strömungsgeschwindigkeit des Gasstromes beziehungsweise Veränderung der lokalen wandnahen Strömungsgeschwindigkeit. Die lokale wandnahe Strömungsgeschwindigkeit / Turbulenz lässt sich mit den Rippenparametern der Wellenamplitude und der Wellenlänge variieren. Die Strömungsgeschwindigkeit des Gasstromes lässt sich auch über den Gaskanalquerschnitt, die Höhe, Breite, oder die Anzahl der Gaskanäle regulieren. Dies wird bevorzugt bei einem U-durchströmten oder S-durchströmten Kühler angewendet. In Bezug auf einen I-durchströmten Kühler ist das Prinzip analog anwendbar.

According to the concept, the gas-side heat input is regulated with two measures:

• - Adjustment of the gas-side surface, which is adjusted by the number of ribs and
• - Increase in turbulence by changing the flow rate of the gas flow or changing the local flow rate near the wall. The local flow velocity / turbulence near the wall can be varied with the rib parameters of the wave amplitude and the wavelength. The flow rate of the gas stream can also be regulated via the gas channel cross section, the height, width or the number of gas channels. This is preferably used in a U-flow or S-flow cooler. The principle can be applied analogously to an I-flow cooler.

The wave amplitude and the wavelength as well as their change over the length of the ribs can be provided and defined in the tool for the rib. A variability in the number of ribs, also called distance fin-to-fin, is specified in the tool.

For the application of the variable channel width for U-flow heat exchangers with a separation of the gas paths of the outward and return flow via a fin, the corrugated fin plate is manufactured in such a way that the entire corrugated fin plate is produced with an average fin spacing and then an area is stretched and in other area is compressed.
If you consider a rib spacing of, for example, approx. 2 mm for the outward path and approx. 1.5 mm for the return path, a rib is produced in the tool, which has an average value of approx. 1.75 mm. By pulling on one side and pressing on the other side, a corrugated rib plate can be produced that has both rib spacings.

An important advantage of the heat exchanger according to the invention is that the heat input from the gas is homogenized in the flow direction over the length of the cooler. The measures in detail and additionally in combination reduce the heat transfer in the gas inlet area and increase it in the gas outlet area.
In relation to a cooler with a non-variable fin geometry, it is possible to improve the heat transfer and the gas-side pressure loss. A major advantage can thus be realized and the cooler can be built smaller with the same characteristic values. Critical areas with regard to thermal stress and cooling water overheating can be largely mitigated.

Direct ecological advantages lie in a smaller component that saves raw materials such as steel and alloying elements. Indirect ecological advantages lie in the improved cooling performance and its positive effects on the operation of an internal combustion engine in order to save fuel and reduce emissions.
A smaller component requires less material to manufacture and thus reduces raw material costs.

• 1: Abgaswärmeübertrager
• 2: Rippengehäuse
• 3: Wellenrippenblech
• 4: Wellenrippenblech in der Draufsicht
• 5: Welle, Kanal
• 6: Wellenrippenblech im Querschnitt
• 7: I-durchströmter Wellenrippenwärmeübertrager, wellenlängenmoduliert
• 8: I-durchströmter Wellenrippenwärmeübertrager, amplitudenmoduliert
• 9: U-durchströmter Wärmeübertrager, amplitudenmoduliert
• 10: U-durchströmter Wärmeübertrager, wellenlängenmoduliert
• 11: U-durchströmter Wärmeübertrager mit Kanalbreitenvariation.

Further details, features and advantages of embodiments of the invention result from the following description of exemplary embodiments with reference to the associated drawings. Show it:

• 1 : Exhaust gas heat exchanger
• 2nd : Rib casing
• 3rd : Corrugated rib plate
• 4th : Top view of corrugated rib plate
• 5 : Wave, channel
• 6 : Cross-section of corrugated rib plate
• 7 : I-flowed corrugated fin heat exchanger, wavelength modulated
• 8th : I-flow through corrugated fin heat exchanger, amplitude modulated
• 9 : U-flow heat exchanger, amplitude modulated
• 10th : U-flow heat exchanger, wavelength modulated
• 11 : U-flow heat exchanger with channel width variation.

In 1 is a finned heat exchanger 1 shown in its basic form. The shown ribbed heat exchanger 1 is used, for example, as an exhaust gas heat exchanger, also known as an EGR cooler. The heat exchanger shown is thus a gas-coolant cooler, in which hot gas is cooled from temperatures of up to 950 ° C. and higher to a coolant temperature of, for example, 95 ° C. and lower. The specific temperature level depends on the area of application and corresponds to the aforementioned temperature level when used as an exhaust gas heat exchanger in internal combustion engines. The corrugated fin heat exchanger 1 cools the gas flow 2nd , which is shown from below at the gas inlet 4th in the finned heat exchanger 1 flows in and after 180 ° deflection in the deflection area 17th to the gas outlet 5 flows back where the gas flow 2nd the finned heat exchanger 1 cooled from originally approx. 950 ° C to 95 ° C. The gas flow 2nd flows through several sets of corrugated fins 8th in which flow paths for the gas flow 2nd are formed. The ribbed packages 8th have undulating ribs that hold the heat of the gas stream 2nd record and to a coolant 3rd submit. The coolant 3rd flows through the corrugated fin heat exchanger 1 from a coolant inlet 6 to a coolant outlet 7 there.

In 2nd is a typical rib case 12th Generic heat exchanger shown, which is shown adjacent in an exploded view from an upper side of the rib housing half 9 , an underside of the rib housing half 11 and a corrugated rib plate in between 10th is shown. Several rib casings 12th form a corrugated rib package 8th according to 1 . Between the ribbed pacts 8th the coolant flows and takes the heat away from the fin housings 12th on the liquid side. On the gas side, the surface is through the corrugated rib plate 10th enlarged.

In 3rd is a corrugated rib plate 10th in perspective in the direction of flow of the gas. The corrugated rib plate 10th is cut on the front and the meandering cross section of the sheet shows the ribs in cross section 14 with a channel width 13 Distance to each other, which are alternately connected to each other on the channel base. Spaced corrugated ribs 14 thus form channels 18th which on one side through the corrugated rib plate 10th even at the bottom of the canal and on the other side due to the 2nd Shown top side of the rib housing half 9 or underside of rib housing half 11 are limited. In the longitudinal direction of the channels 18th these form the waveform of the limiting wave rib 14 after. The gas flows in the channels 18th and follows the wave shape of the wave ridges 14 .

In 4th is a corrugated rib plate 10th after 3rd shown in top view. The corrugated ribs limit the channels 18th , shown here in a configuration according to the prior art in even sinusoidal waves.

In 5 is a wave rib 14 and thus analogously a wave-shaped channel 18th shown. The wave shape of the wave rib 14 is characterized by a wavelength 15 , represented as the distance between two wave troughs and a wave amplitude 16 as the distance between Wellenberg and Wellental.

In 6 is a corrugated rib plate in the upper part 10th in cross section with the channels that form 18th shown. In the lower part of the figure is the corrugated rib plate 10th shown edited in two areas. A stretched area 19th shows a corrugated rib plate stretched in the direction of the arrow and a compressed area 20th shows a compressed corrugated rib plate 10th . As shown The embodiment is the production of corrugated rib plates 10th with different areas, a stretched area 19th and a compressed area 20th with different channel widths of the channels 18th shown.

In 7 is an I-flow finned heat exchanger 1 with wave ribs according to the invention 14 and wavy channels 18th shown by a gas stream 2nd The flow from left to right is from a gas inlet to a gas outlet 5 . The wave ribs 14 and with it the channels 18th have a wave-like shape, the wave itself being modulated. In the lower part of the 7 is a wave rib 14 shown whose wavelength 15 gets smaller. In the illustrated embodiment, the wavelength 15 the wave from the gas inlet 4th to the gas outlet 5 steadily shorter. By shortening the wavelength 15 , which is getting smaller and smaller in the example shown, does justice to the fluid properties of the temperature of the gas that changes over the flow length.

In 8th is in turn an I-flow finned heat exchanger 1 for a gas stream 2nd with wave ribs 14 and channels formed from it 18th shown, the wave ribs 14 as in the lower part of 8th shown an increasing wave amplitude 16 from the gas inlet 4th to the gas outlet 5 points out.

The teaching of the invention can now be seen in the fact that the changing properties of the hot gas through the flow through the fin heat exchanger 1 also has a change in the channel geometry in order to optimally design the heat transfer and in particular the quality of the heat transfer over the length flowed through. According to the state of the art, shaft fin heat exchangers with a constant shaft come from the gas inlet 4th to the gas outlet 5 towards a significant deterioration in heat transfer.

In 9 is a finned heat exchanger 1 shown schematically in a U-flow design. The gas flow 2nd flows at the gas inlet 4th in the corrugated fin heat exchanger 1 one, is along the channels to the deflection area 17th guided, redirected there and at the gas outlet 5 from the corrugated fin heat exchanger 1 led out. The wave ribs 14 have one from the gas inlet 4th beginning to gas exit 5 increasing wave amplitude 16 . The schematic representation of the increase in amplitude is shown separately for the outward path above and for the return path below the finned heat exchanger. The amplitude of the wave rib 14 begins in the axis passage of the shaft at 0.0 mm and rises to values of 2.5 mm at the gas outlet 5 on. Depending on the boundary conditions, amplitudes between 0.8 mm and 2.0 mm are preferably used.

In 10th is a U-flow through corrugated fin heat exchanger 1 analogous to 9 with changing wavelength 15 the wave ribs 14 shown, the wavelength 15 sinks. The wavelength 15 decreases from an input value of 20 mm to an output value at the gas outlet 5 to 5 mm.

A particularly preferred embodiment of the corrugated fin heat exchanger 1 consists in the combination of increasing wave amplitude 16 and decreasing wavelength 15 from the gas inlet 4th to the gas outlet 5 .

In 11 is a finned heat exchanger 1 shown, which in the construction according to the 9 and 10th is executed, however, the corrugated fin plate 10th in terms of channel width 13 is modified. The channel width 13 changes steadily on the way of gas flow 2nd from the gas inlet 4th to the gas outlet 5 there and gets smaller and smaller. The channel width 13 , approximately represented by the rib spacing, decreases from a value of 5.0 mm to 1.5 mm, but this is not implemented in the drawing. The channel width 13 results exactly from the mean rib spacing minus the rib thickness.

The combination of the measures of increasing the wave amplitude is particularly preferred 16 , a decrease in wavelength 15 and a reduction in the channel width 13 from the gas inlet 4th to the gas outlet 5 there.

Reference list

1

Finned heat exchanger, exhaust gas heat exchanger

2nd

Gas flow

3rd

Coolant

4th

Gas inlet

5

Gas outlet

6

Coolant inlet

7

Coolant outlet

8th

Ribbed packages

9

Top of the rib half of the housing

10th

Ribbed sheet

11

Bottom of the rib half of the housing

12th

Rib casing

13

Channel width

14

Wave rib

15

wavelength

16

Wave amplitude

17th

Deflection area

18th

channels

19th

Stretched area

20th

Compressed area

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2010112201 A [0005]
• DE 102005007692 A1 [0006]

Claims (12)

Rib heat exchanger (1) for cooling hot gas, in particular exhaust gas heat exchanger for internal combustion engines, comprising a gas inlet (4) and a gas outlet (5) for a gas flow (2) in channels (18) formed by ribs spaced apart from one another, characterized in that the channels ( 18) are wave-shaped by means of wave ribs (14) and have a wave amplitude (16) and a wavelength (15), the wave amplitude (16) of the wave-shaped channels (18) increasing from the gas inlet (4) to the gas outlet (5) and / or the wavelength (15) of the wavy channels (18) from the gas inlet (4) to the gas outlet (5) becomes smaller. Finned heat exchanger (1) after Claim 1 , characterized in that the wave amplitude (16) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) increases continuously. Finned heat exchanger (1) after Claim 1 , characterized in that the wave amplitude (16) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) rises continuously. Finned heat exchanger (1) according to one of the Claims 1 to 3rd , characterized in that the wave amplitude (16) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) increases in the range from 0.0 mm to 2.5 mm. Finned heat exchanger (1) according to one of the Claims 1 to 4th , characterized in that the wavelength (15) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) is continuously smaller. Finned heat exchanger (1) according to one of the Claims 1 to 4th , characterized in that the wavelength (15) of the wavy channels (18) from the gas inlet (4) to the gas outlet (5) is continuously smaller. Finned heat exchanger (1) according to one of the Claims 1 to 6 , characterized in that the wavelength (15) of the corrugated channels (18) from the gas inlet (4) to the gas outlet (5) becomes smaller from 20 mm to 5 mm. Finned heat exchanger (1) according to one of the Claims 1 to 7 , characterized in that the channel width (13) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) is constantly narrowing. Finned heat exchanger (1) according to one of the Claims 1 to 8th , characterized in that the channel width (13) of the wave-shaped channels (18) from the gas inlet (4) to the gas outlet (5) becomes smaller from 5.0 mm to 1.5 mm. Finned heat exchanger (1) according to one of the Claims 1 to 9 , characterized in that the corrugated fin heat exchanger (1) is designed as an I-flow heat exchanger with gas inlet (4) and gas outlet (5) on opposite sides of the heat exchanger. Finned heat exchanger (1) according to one of the Claims 1 to 10th , characterized in that the corrugated fin heat exchanger (1) is designed as a U-flow heat exchanger with gas inlet (4) and gas outlet (5) on one side of the heat exchanger. Method for producing a finned heat exchanger (1) according to one of the Claims 1 to 8th , characterized in that a corrugated fin plate (10) with the same channel widths (13) is produced and then the corrugated fin plate (10) is stretched across the width of the corrugated fin plate (10) in a stretched area (19) and in a compressed area (20) is compressed transversely to the channel direction in such a way that the channel width (13) is enlarged in the stretched area (19) and reduced in the compressed area (20).

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