CN110566326A

CN110566326A - Device for exhaust gas aftertreatment with thermal insulation

Info

Publication number: CN110566326A
Application number: CN201910489136.6A
Authority: CN
Inventors: F·格贝尔; B·范登赫维尔; R·弗里奇
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2018-06-06
Filing date: 2019-06-06
Publication date: 2019-12-13
Also published as: DE102018208924A1

Abstract

The application is directed to an apparatus for exhaust aftertreatment having thermal insulation. An exhaust gas aftertreatment apparatus is provided comprising a first catalytic converter device and an adjoining second catalytic converter device, the first and second catalytic converter devices being arranged spatially adjacent to each other. The first catalytic converter device includes first and second flow tubes and is configured to direct exhaust gas through the first flow tube in a first flow direction and then through the second flow tube in a second flow direction opposite the first flow direction of operation. The second catalytic converter device includes a third flow tube spatially and flowwise arranged between the first and third flow tubes, and is configured to direct the exhaust gas through the third flow tube in a third flow direction opposite to the second flow direction operation after the exhaust gas exits the second flow tube. At least one means for thermal insulation is spatially arranged between the first and second catalytic converter devices.

Description

Device for exhaust gas aftertreatment with thermal insulation

Technical Field

The invention relates to a device for exhaust gas aftertreatment, a method for operating a device for exhaust gas aftertreatment, and a motor vehicle.

Technical Field

In the context of exhaust gas aftertreatment of motor vehicles, it is attempted to arrange the respective catalytic converters in a manner which is as space-saving as possible. For this purpose, a flow tube with a return region is usually provided. Thus, the exhaust gas initially flows in a first flow direction and is then deflected in a second flow direction opposite to the first flow direction of travel. In this way, in compact catalytic converter applications, at least two catalytic converter devices or substrates are arranged parallel to each other on the smallest possible space adjacent to each other.

In the case where one of the catalytic converter device or substrate includes a diesel particulate filter, it is necessary to periodically perform a regeneration cycle. During these regeneration cycles, very high gas temperatures are generated and the temperature of the components reaches above 700 ℃. If two catalytic converter devices or substrates are arranged in a common housing in close proximity to each other, an asymmetric heat distribution is generated during the regeneration cycle due to radiation of heat or flow or convection of heat from the first catalytic converter device to the second catalytic converter device, and vice versa. Such temperature distribution can lead to high temperature gradients and thermal stresses in the substrate. Such stresses may limit the possible applications of the substrate, particularly in the context of diesel particulate filtration applications.

Catalytic converter devices with a thermal insulation layer are disclosed, for example, in documents US2017/0122180a1 and US5,589,144. An insulating air layer surrounding the filter block is described in document US7,611,561B2.

disclosure of Invention

It is an object of the present invention to provide an advantageous device for exhaust gas aftertreatment, which reduces the above-mentioned difficulties in respect of high temperature differences.

The object is achieved by an arrangement for exhaust gas aftertreatment, a method for operating an arrangement for exhaust gas aftertreatment and a motor vehicle. Further advantageous configurations of the invention are included.

An arrangement according to the invention for the aftertreatment of exhaust gases comprises a first catalytic converter device and a second catalytic converter device, which adjoins the first catalytic converter device in the flow direction of the exhaust gases. The first catalytic converter device and the second catalytic converter device are arranged spatially adjacent to each other (e.g., next to each other). The first catalytic converter device comprises a first flow pipe and a second flow pipe. The first catalytic converter device is configured to direct exhaust gas through the first flow duct in a first flow direction and subsequently through the second flow duct in a second flow direction opposite to the first flow direction operation. The second catalytic converter device comprises a third flow pipe. The second flow pipe of the first catalytic converter device is spatially and fluidly arranged between the first flow pipe of the first catalytic converter device and the third flow pipe of the second catalytic converter device. The second catalytic converter device is configured to direct exhaust gas through the second catalytic converter device in a third flow direction opposite the second flow direction operation after the exhaust gas exits the second flow duct of the first catalytic converter device. The third flow direction can run, for example, parallel to the first flow direction. At least one means for insulating heat is spatially arranged between the first catalytic converter device and the second catalytic converter device. The means for heat insulation are preferably arranged spatially between the second flow tube and the third flow tube.

The arrangement according to the invention has the advantage that the high temperatures occurring in particular in the context of a regeneration process in the first catalytic converter device or in the second catalytic converter device influence the respective other catalytic converter device to a reduced extent due to thermal radiation or thermal flows. In this way the above-mentioned undesirable temperature gradients are reduced.

In a preferred variant, the first catalytic converter device and the second catalytic converter device are arranged in a common housing. The first catalytic converter device may comprise a central axis and the second catalytic converter device may comprise a central axis, wherein the central axes may run parallel to each other. In another variation, the first flow tube of the first catalytic converter device may include a central axis, and the second flow tube may be disposed radially outward of the first flow tube. In particular, the second flow tube may radially surround the first flow tube.

In the context of the present invention, flow directions running opposite to one another mean that the respective flow tubes have in each case a central axis which encloses an angle of (enclose)135 degrees (135 °) to 180 degrees (180 °), or 0 degrees (0 °) to 45 degrees (45 °). In an advantageous variant, the first and/or second and/or third flow tubes comprise a central axis. In each case, the central axis may enclose an angle of 0 degrees (0 °) to 45 degrees (45 °).

The first flow direction and the second flow direction, and/or the second flow direction and the third flow direction may enclose an angle between 135 degrees and 225 degrees. In each case, the central axis may fix (fix) the flow direction in the respective flow tube. For example, the central axis of the first flow tube may fix a first flow direction, the central axis of the second flow tube may fix a second flow direction, and the central axis of the third flow tube may fix a third flow direction.

the first catalytic converter device may comprise an outer wall, the second catalytic converter device may comprise an outer wall, and the at least one means for insulating heat may be arranged between the outer wall of the first catalytic converter device and the outer wall of the second catalytic converter device. An advantage of this arrangement is that the outer wall of the first catalytic converter device and the outer wall of the second catalytic converter device do not have to be completely insulated and thus costs associated with such a solution can be saved.

An arrangement according to the invention for exhaust gas aftertreatment may comprise more than two catalytic converter devices which adjoin one another spatially and fluidically in the described manner, for example may be arranged next to one another. At least one of the catalytic converter devices of the arrangement according to the invention may comprise a diesel particulate filter.

The means for insulating may comprise a mat, in particular configured as a mat. In this case, the mat may have thermal insulating properties, for example comprising or consisting of a thermal insulating material. An example of this is shown in fig. 1 and 2.

For example, E-glass fiber fabrics/mats, silicate fiber fabrics/mats or mineral fiber mats may be used as suitable materials and application forms for insulating the very hot parts. The insulation efficiency depends on the thickness of the fabric/mat or the number of layers used.

In another variant, the means for insulating heat may comprise a coating, in particular configured as a coating. In this case, a heat insulating layer is preferably present on the surface region of the outer wall of the first catalytic converter device and/or the second catalytic converter device. In this case, the region of the outer wall adjoining the outer wall of the respective other catalytic converter device or arranged adjacent to said outer wall is advantageously coated. An advantage of only partially coating the outer surface of one or both catalytic converter devices is that only small surfaces are coated and thus the cost of a complete coating can be saved.

In another variant, the means for insulating may comprise at least one sealed chamber. For example, the cavity may be filled with air or a different gas or contain a vacuum. Preferably, there is a sealed air layer between the first catalytic converter device and the second catalytic converter device. The sealed cavity may be implemented, for example, to create a volume of air sealed by a metal wall (e.g., a metal plate).

in an advantageous variant, the means for insulating comprise a plurality of flow tubes. For example, between the first catalytic converter device and the second catalytic converter device there may be an air flow duct, in particular at least one flow duct having an air inlet and an air outlet, wherein the air for cooling may flow through the at least one flow duct. The outer wall of the catalytic converter device may form a wall region of the flow duct, in particular of the at least one airflow duct. In this way, passive cooling is achieved. An example of this is shown in fig. 7 and 8.

In another variant, at least one flow pipe (e.g. a plurality of flow pipes) is arranged between the first catalytic converter device and the second catalytic converter device, in particular between an outer wall of the first catalytic converter device and an outer wall of the second catalytic converter device, which at least one flow pipe is designed for a fluid, in particular a cooling fluid, to flow through the at least one flow pipe. The at least one flow tube may include an inlet and an outlet. A cooling fluid, for example a gas such as in particular air or a liquid such as water or oil, may be guided through the flow tube. This enables active cooling. An example of this is shown in fig. 9 and 10.

In the context of the method according to the invention for operating an arrangement for exhaust gas aftertreatment, the arrangement for exhaust gas aftertreatment comprises a plurality of flow pipes as an arrangement for thermal insulation, through at least one of which a fluid, preferably a cooling fluid, such as air, water or oil, is guided, for example pumped. The method according to the invention has the advantages cited in connection with the device according to the invention. In particular, there is the advantage of achieving active cooling which can be flexibly adapted to the respective occurring temperature. For example, in the case of regeneration of one of the catalytic converter devices, the cooling fluid can be guided through the at least one flow tube at a specific throughflow rate. In this way, efficient cooling is available, which is particularly efficient since it can be used in a controlled manner as required.

The motor vehicle according to the invention comprises a device for exhaust gas aftertreatment according to the invention. The motor vehicle has the features and advantages already cited in this context. The motor vehicle may be an automobile, a heavy goods vehicle or a motorcycle.

Drawings

the invention will be explained in more detail below on the basis of exemplary embodiments with reference to the drawing. Although the invention has been further shown and described in detail with reference to preferred exemplary embodiments thereof, the invention is not limited by the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

Fig. 1 schematically shows a perspective view of a device for exhaust gas aftertreatment according to the invention.

Fig. 2 schematically shows a perspective and sectional view of the device for exhaust gas aftertreatment shown in fig. 1.

Fig. 3 schematically shows a perspective view of another variant of the device for exhaust gas aftertreatment according to the invention.

Fig. 4 schematically shows a perspective and sectional view of the device for exhaust gas aftertreatment shown in fig. 3.

Fig. 5 schematically shows a perspective view of another variant of the device for exhaust gas aftertreatment according to the invention.

Fig. 6 schematically shows a perspective and sectional view of the device for exhaust gas aftertreatment shown in fig. 5.

Fig. 7 schematically shows a perspective view of another variant of the device for exhaust gas aftertreatment according to the invention.

Fig. 8 schematically shows a perspective and sectional view of the device for exhaust gas aftertreatment shown in fig. 7.

Fig. 9 schematically shows a perspective view of another variant of the device for exhaust gas aftertreatment according to the invention.

fig. 10 schematically shows a perspective and sectional view of the device for exhaust gas aftertreatment shown in fig. 9.

Fig. 11 schematically shows a motor vehicle according to the invention.

Detailed Description

Fig. 1 shows a perspective view of a device 1 for exhaust gas aftertreatment according to the invention. Fig. 2 schematically shows a perspective and sectional view of the device 1 for exhaust gas aftertreatment shown in fig. 1.

the arrangement 1 for exhaust gas aftertreatment according to the invention comprises a first catalytic converter device 2 and a second catalytic converter device 3. The first catalytic converter device 2 comprises an exhaust gas inlet 4 and an exhaust gas outlet 5. The second catalytic converter device 3 comprises an exhaust gas inlet 6 and an exhaust gas outlet 7 connected to the exhaust gas outlet 5 of the first catalytic converter device. The first catalytic converter device 2 comprises an outer wall 8. The second catalytic converter device 3 comprises an outer wall 9. In the variant shown, the means for thermal insulation are arranged between the outer walls 8 and 9 in the form of thermal insulation pads 10.

The first catalytic converter device 2 comprises a first flow duct 11 and a second flow duct 12. The second catalytic converter device 3 comprises a third flow pipe 13. The second flow tube 12 is arranged downstream of the first flow tube 11. A third flow duct 13 is arranged downstream of the second flow duct 12. The second flow tube 12 is spatially arranged between the first flow tube 11 and the third flow tube 13.

The first flow tube 11 includes a central axis 14. The second flow tube 12 includes a central axis 15. The third flow tube 13 includes a central axis 16. In the variant shown, the central axis 14, the central axis 15 and the central axis 16 are arranged parallel to one another. In the variant shown, the second flow tube 12 is arranged radially outside the first flow tube 11. The central axis simultaneously fixes the flow direction in the respective flow tubes.

Exhaust gas flows through the first flow pipe 11 in a flow direction 17. The flow direction 17 runs parallel to the central axis 14. The exhaust gas then flows through the second flow tube 12 in a flow direction 18. The flow direction 18 runs parallel to the central axis 15 and counter to the flow direction 17. In other words, in the variant shown, the flow direction 17 and the flow direction 18 enclose an angle of 180 °. After the exhaust gas leaves the second flow pipe 12, the exhaust gas flows through the third flow pipe 13 in a flow direction 19. The flow direction 19 runs parallel to the central axis 16 and counter to the flow direction 18. Thus, in the variant shown, the flow direction 18 and the flow direction 19 enclose an angle of 180 °. Furthermore, in the variant shown, the flow direction 17 and the flow direction 19 run parallel to one another. Configurations deviating from this configuration are also possible. Thus, the flow direction 17 and the flow direction 18, and/or the flow direction 18 and the flow direction 19, may enclose an angle between 135 ° and 180 ° in each case.

In the variant shown in fig. 3 and 4, a coating 20 made of a thermally insulating material is applied on the outer wall 9 of the second catalytic conversion device 3. Alternatively, the coating 20 may also be applied on the outer wall 8 of the first catalytic converter device 2 or on the outer walls of both the catalytic converter device 2 and the catalytic converter device 3. In the variant shown, the coating is applied only in the region of the outer walls 9 of the catalytic converter device 2 and of the catalytic converter device 3 where the outer walls 8 and 9 abut against each other.

In the variant shown in fig. 5 and 6, there is a sealed chamber 30 between the outer wall of the first catalytic converter device and the outer wall of the second catalytic converter device. The cavity 30 is filled with air, for example. Alternatively, the cavity 30 may be filled with a gas (e.g., air), wherein the pressure is below atmospheric pressure or with a vacuum. In this way, an effective cooling layer is achieved between the catalytic converter device 2 and the catalytic converter device 3. The outer walls 8 and 9 may also partially form the walls of the cavity 30.

In the variant shown in fig. 7 and 8, a flow duct 40 in the form of a chamber with a plurality of openings 41 is provided between the outer wall 8 of the first catalytic converter device 2 and the outer wall 9 of the second catalytic converter device 3. Air can flow from the outside through the openings 41 through the cavity 40 and thereby cause cooling of the outer walls 8 and 9.

In the variant shown in fig. 9 and 10, at least one flow duct 40 is provided between the outer wall 8 of the catalytic converter device 2 and the outer wall 9 of the catalytic converter device 3. The flow tube 40 includes an inlet 43 and an outlet 44. Through the inlet 43, a cooling fluid (e.g. a gas or a liquid, in particular air, water or oil) may be guided through the flow tube 40 to the outlet 44. In this way, the outer surfaces 8 and 9 can be actively cooled.

Fig. 11 schematically shows a motor vehicle 45 according to the invention. The motor vehicle 45 comprises a device 1 for exhaust gas aftertreatment according to the invention as described above.

List of reference numerals:

Device for exhaust gas aftertreatment

2 first catalytic converter device

3 second catalytic converter device

4 exhaust inlet

5 exhaust outlet

6 exhaust inlet

7 exhaust outlet

8 outer wall

9 outer wall

10 Heat insulation pad

11 first flow tube

12 second flow tube

13 third flow pipe

14 central axis

15 central axis

16 central axis

17 direction of flow

18 direction of flow

19 direction of flow

20 coating layer

30 sealed cavity

40 flow tube

41 opening

42 direction of flow

43 inlet

44 outlet

45 motor vehicle

Claims

1. An arrangement (1) for exhaust gas aftertreatment, comprising a first catalytic converter device (2) and a second catalytic converter device (3), which second catalytic converter device (3) adjoins the first catalytic converter device (2) in a flow direction (17, 18) of the exhaust gas, which first and second catalytic converter devices are arranged spatially adjacent to each other, which first catalytic converter device (2) comprises a first flow duct (11) and a second flow duct (12), and which first catalytic converter device (2) is configured to guide the exhaust gas through the first flow duct (11) in a first flow direction (17) and subsequently through the second flow duct (12) in a second flow direction (18) running opposite to the first flow direction, which second catalytic converter device (3) comprises a third flow duct (13), the second flow duct (12) of the first catalytic converter device (2) being arranged spatially and in flow between the first flow duct (11) of the first catalytic converter device (2) and the third flow duct (13) of the second catalytic converter device (3), and the second catalytic converter device (3) being configured to guide exhaust gases through the third flow duct (13) in a third flow direction (19) running opposite to the second flow direction after the exhaust gases leave the second flow duct (12) of the first catalytic converter device (2),

Wherein

At least one means for thermal insulation (10, 20, 30, 40) is spatially arranged between the first catalytic converter device (2) and the second catalytic converter device (3).

2. The device (1) according to claim 1,

Wherein

Means (10, 20, 30, 40) for thermal insulation are spatially arranged between the second flow tube (12) and the third flow tube (13).

3. The device (1) according to claim 1 or claim 2,

Wherein

The first catalytic converter device (2) and the second catalytic converter device (3) comprise in each case an outer wall (8, 9) and the means for insulating heat (10, 20, 30, 40) are arranged between the outer wall (8) of the first catalytic converter device (2) and the outer wall (9) of the second catalytic converter device (3).

4. The device (1) according to any one of claims 1 to 3,

Wherein

The first flow tube (11) comprises a central axis (14), and/or the second flow tube (12) comprises a central axis (15), and/or the third flow tube (13) comprises a central axis (16), and the central axes enclose an angle between 0 and 45 degrees in each case.

5. The device (1) according to any one of claims 1 to 4,

Wherein

The first flow direction (17) and the second flow direction (18), and/or the second flow direction (18) and the third flow direction (19) enclose an angle between 135 degrees and 225 degrees.

6. The device (1) according to any one of claims 1 to 5,

wherein

At least one of the catalytic converter devices (2, 3) comprises a diesel particulate filter.

7. The device (1) according to any one of claims 1 to 6,

Wherein

The means for insulating comprises a mat (10).

8. The device (1) according to any one of claims 1 to 7,

Wherein

The means for insulating heat comprises a coating (20).

9. the device (1) according to any one of claims 1 to 8,

Wherein

The means for insulating comprise at least one sealed chamber (30).

10. The device (1) according to any one of claims 1 to 9,

Wherein

The means for insulating comprises a plurality of flow tubes (40).

11. Method for operating a device (1) for the aftertreatment of exhaust gases according to claim 10, wherein

Fluid is led through at least one of the flow tubes (40).

12. A motor vehicle (45) comprising an arrangement (1) for exhaust gas aftertreatment according to any one of claims 1 to 10.