DE102014104224A1 - exhaust system - Google Patents

Abstract

Exhaust system, in particular exhaust system of an internal combustion engine, with an exhaust line (2) for guiding an exhaust gas flow and a device (3) for introducing a fluid, in particular a water-urea mixture or a fuel, into the exhaust gas flow through an opening in the exhaust line (2) , wherein for improving the pipe flow in the exhaust line (2) in front of the fluid introduction opening, a flow divider (7) is arranged.

Description

The present invention relates to an exhaust system, in particular an exhaust system of an internal combustion engine, with an exhaust line for guiding an exhaust gas stream and a device for introducing a fluid, in particular a water-urea mixture or a fuel, in the exhaust gas flow through an opening in the exhaust line.

An object of the invention is to guide the flow within an exhaust line with a device for introducing a fluid such as a water-urea mixture or a fuel, in particular in the case of an angled exhaust line, so that the exhaust gas flow following the introduction point as homogeneous as possible is. This is particularly important in exhaust systems in which a cross-section narrowing component, for example a mixing element, is located in the exhaust line downstream of the introduction point, which generates high pressure losses in the case of inhomogeneous flow.

Another object of the invention is to optimize the introduction of the fluid into the exhaust stream and in particular to ensure a good mixing of the exhaust gas and the introduced fluid.

These objects are achieved in an exhaust system of the type mentioned above in that a flow controller is arranged in the exhaust line in front of the fluid introduction opening.

To divide the exhaust gas flow, at least one guide element is preferably used. The guide element is preferably attached to a wall of the exhaust line and extends in particular to the pipe center axis. In an angled or curved exhaust gas stream, the guide element is preferably mounted on the outside of the bend. The guide element is preferably inclined to the tube central axis in the flow direction, in particular by an angle of minus 60 ° to plus 70 °, preferably 30 °. Furthermore, the guide element is preferably spaced by a tube radius from the downstream insertion axis.

The guide can be attached to the exhaust system and complete flush with this. However, it is also possible to provide flow openings, in particular to space the guide element from the wall of the exhaust gas line.

The guide element can be produced as a triangular element and in particular made of sheet metal. The triangle preferably has a lateral leg angle at the side which is flown by the main flow, which can basically extend from 0 to 180 °. A preferred leg angle is 45 °. However, the angles of the two legs of the triangle can also be different from one another in order to achieve as homogeneous a flow as possible after an angling or bending as a result of an asymmetrical division.

Embodiments of the invention are illustrated in the drawings and are described below:

1 shows a first variant with an angled exhaust system,

2 shows a different view on the variant of 1 .

3a to 3c show different variants of a flow divider,

4 shows a further variant of an angled exhaust gas line,

5a to 5d show different flow dividers and

6 shows a further variant with a straight exhaust line.

The in 1 illustrated exhaust system 2 the patented device 1 has an angling. In the area of angling is an injector 3 provided for introducing a fluid. 4 indicates the spray of the introduced fluid.

At the point of introduction is a mixer 5 available. Its wake area is with 6 designated.

Before the application point is at a distance from the spray 4 a guiding element 7 arranged, which divides the exhaust gas stream represented by arrows. The shape of the guiding element 7 is in 2 recognizable. It is a triangular shape with two equal-length legs, each extending at an angle of approximately 45 ° to the main flow direction. This leg angle and the leg length can be varied, and also different for both legs. This allows the most homogeneous possible exhaust gas flow downstream of the introduction point and in particular in the region of the mixer 5 be achieved.

In the 3a to 3c are different variants of the guide element 7 shown. Accordingly, the legs of the guide element 7 be formed curved or together form a boomerang shape or as in 3b just connect to each other.

As in 4 can be shown, to the guide element 7 another flow guide 8th to be appropriate. Thus, the flow can be further influenced and optimized.

The guiding element 7 can be flush with the pipe wall of the exhaust system 2 be trained as in 5a is shown. The guiding element 7 but like in 5b also shown only partially flush with the pipe wall. Furthermore, the guide element 7 about a carrier 9 be connected to the pipe wall, like this 5c shows. Finally, as in 5d shown in the area of the guide element 7 another channel 10 be arranged with a small diameter, which a partial exhaust gas flow in the region of the spray cone 4 passes.

All variants shown above can also be used in a straight exhaust line, as in 6 is shown.

LIST OF REFERENCE NUMBERS

1

contraption

2

exhaust gas line

3

injector

4

spray

5

mixer element

6

wake region

7

vane

8th

another guiding element

9

holder

10

guide channel

Claims (8)

Exhaust system, in particular exhaust system of an internal combustion engine, with an exhaust line ( 2 ) for guiding an exhaust gas flow and a device ( 3 ) for introducing a fluid, in particular a water-urea mixture or a fuel, into the exhaust gas flow via an opening in the exhaust gas line (US Pat. 2 ), characterized in that in the exhaust line ( 2 ) in front of the fluid introduction opening a flow divider ( 7 ) is arranged Exhaust system according to claim 1, characterized in that the exhaust gas line ( 2 ) is angled or curved in the introduction area. Exhaust system according to claim 1 or 2, characterized in that after the introduction point a mixing element ( 5 ) is arranged. Exhaust system according to one of the preceding claims, characterized in that the flow divider ( 7 ) differs the exhaust flow over the cross section differently. Exhaust system according to one of the preceding claims, characterized in that the flow divider ( 7 ) is formed as a guide element, which on a wall of the exhaust line ( 2 ), in the case of a curved or angled exhaust line, in particular on the outside of the curve, wherein the guide element ( 7 ) preferably extends to about the pipe center axis. Exhaust system according to one of the preceding claims, characterized in that the guide element is formed as an angle piece, the two legs are inclined to the pipe center axis at an angle between 0 ° and 180 °, wherein the angle with each other also different sizes and the legs can be different lengths. Exhaust system according to one of the preceding claims, characterized in that on the flow divider ( 7 ) another flow guide ( 8th ) is attached. Exhaust system according to one of the preceding claims, characterized in that in the region of the flow divider ( 7 ) a guide channel ( 10 ) is provided, through which a partial exhaust gas flow directly to the spray ( 4 ) can be directed.

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