CN111406149A - Exhaust equipment for internal combustion engines - Google Patents

Abstract

The invention relates to an exhaust system for an internal combustion engine, wherein at least one first and one second exhaust gas purification device are provided in the exhaust system, wherein the first exhaust gas purification device is arranged upstream of the second exhaust gas purification device in the flow direction of the exhaust gas and can be traversed by the exhaust gas, and the second exhaust gas purification device can be traversed by the exhaust gas, wherein the first exhaust gas purification device has a perforation for the exhaust gas in the flow direction of the exhaust gas, which perforation is connected via an exhaust funnel to a flow cross section of the second exhaust gas purification device in a manner such that the exhaust gas is guided. The design of the exhaust system according to the invention makes it possible to increase the effective flow cross section of the first and second exhaust gas purification devices with the same overall volume.

Description

Exhaust equipment for internal combustion engines

technical field

The present invention relates to an exhaust system for an internal combustion engine having the features stated in the preamble of claim 1 .

Background technique

In principle, particles, in particular soot particles, are produced in the combustion chamber of the internal combustion engine during incomplete combustion and/or when the fuel-air mixture is not sufficiently prepared. One of the main reasons here is the insufficient atomization of the fuel, especially in direct injection gasoline internal combustion engines, and therefore the wetting of the combustion chamber walls with the fuel or the formation of fuel droplets on the cold combustion chamber walls.

并且会极大地影响肺部功能、削弱心血管系统并且因此导致严重限制身体机能。The reduction of ultrafine particle emissions from the exhaust gas of direct-injection gasoline internal combustion engines is primarily important in terms of adverse health effects. Particles (nanoparticles) having a size of less than 0.1 nm are called ultrafine particles. Particles of the stated size are alveolar accessible

And can greatly affect lung function, weaken the cardiovascular system and thus lead to severe limitation of bodily functions.

For these reasons, it is expected that direct-injection gasoline internal combustion engines may also be equipped with particulate filters in addition to diesel internal combustion engines in the future in order to avoid damage to human health.

For example, German publication DE 10 2009 058 698 A1 discloses an internal combustion engine with a supply system for combustion air and an exhaust system, wherein the exhaust system has at least one exhaust line in which a first exhaust line is arranged. A particle filter and a second particle filter is provided downstream. In this context, provision is made for the second particulate filter to be provided with a differential pressure sensor in order to determine the differential pressure between a position upstream and a position downstream of the second particulate filter. The task of describing the internal combustion engine is solved by the arrangement, in which the efficiency of the soot particle filter can be determined by means of the associated method.

Regarding the technical field, further reference is made to European patent document EP2710239B1. From said document, an exhaust system for an internal combustion engine is known, which has an exhaust gas path with two parallel exhaust lines (main line and auxiliary line), main line and auxiliary line into the common exhaust line. An absorber for reversibly absorbing unburned hydrocarbons (HC) and/or nitrogen oxides (NOx) is provided in the secondary line, with an absorber for selectively diverting the exhaust gas flow in the main line and/or in the secondary line The regulating device is guided in the line and has a main catalytic converter arranged downstream of the parallel exhaust line in the common exhaust line, wherein a guide exhaust gas flow with a tubular configuration is provided upstream of the absorber a gas permeable element, the downstream end of which is connected to an inner inlet opening in said parallel exhaust lines without an inner pipe, which supports the absorber and separates the parallel exhaust lines, and which A plurality of through openings are provided for each exhaust gas flow, which separates the upstream end of the secondary line from the rest of the area where the exhaust gas flow is directed.

Furthermore, an exhaust system for an internal combustion engine is known from German patent application DE 10 2016 203 369 A1, which has an exhaust pipe with a first longitudinal axis, which is connected to at least one exhaust gas outlet of the internal combustion engine to conduct exhaust gas . A first exhaust gas cleaning device having a second longitudinal axis is arranged in the exhaust pipe, through which the exhaust gas can flow largely parallel to the second longitudinal axis. The second longitudinal axis of the first exhaust gas cleaning device and the first longitudinal axis of the exhaust pipe are arranged at an angle of between 60° and 120°.

Furthermore, German publication DE 10329436 A1 discloses an exhaust gas purification system for an internal combustion engine of a motor vehicle and a method for purifying an exhaust gas flow of an internal combustion engine, the exhaust gas purification system having a first exhaust gas purification through which the exhaust gas can flow The present invention is based on the element and the second exhaust gas cleaning element, which is flow parallel to the first exhaust gas cleaning element, through which the exhaust gas can flow. According to the invention, in the exhaust gas cleaning system, the second exhaust gas cleaning element is arranged spatially behind the first exhaust gas cleaning element in such a way that the vertical projection of the gas outlet surface of the first exhaust gas cleaning element at least partially covers the second exhaust gas cleaning element the gas inlet face.

Based on future legislation requiring the use of gasoline particulate filters (OPF). As a result, the exhaust gas back pressure increases, as a result of which the power potential of the internal combustion engine is reduced. Therefore, the optimization goal is to maximize the OPF cross-sectional area in order to minimize the exhaust gas back pressure, taking into account the construction space available in the motor vehicle. A possibility to increase the effective OPF cross-section is to arrange parallel lines (cascading) one after the other. Here, bypass pipes are guided laterally past the OPF in order to connect the other OPFs.

This cascade has the following disadvantages:

- bypass boot consumes valuable OPF cross-section;

- the exhaust gas mass flow can only be adjusted by reducing the cross-sectional area in the OPF or bypass;

- In combustion engines with exhaust gas turbochargers/catalysts, the cascaded OPF can only be adjusted as an integral component, which has application disadvantages;

- The desired carbon black production requires excess oxygen and a sufficiently high unit temperature for the combustion of the carbon black. However, the bypass to the rear OPF promotes heat loss so that the second OPF is always cooler than the first; this results in uneven regeneration. In order to protect the components, the maximum soot loading in one of the OPFs must be taken as a starting point, so that active regeneration must be performed more frequently and/or the internal combustion engine must be reduced in power earlier.

SUMMARY OF THE INVENTION

The task of the present invention is to avoid the abovementioned disadvantages.

Said task is solved by the features in the characterizing part of claim 1 .

According to the invention, the bypass exhaust gas mass flow of the second OPF does not pass laterally through the first OPF, but through the first OPF.

In an advantageous manner, the cross section valuable for exhaust gas purification is not wasted, since the OPF wall is at the same time a bypass wall. Since there is no outward heat transfer, the temperature of the first OPF and the second OPF is practically the same. The bypass exhaust mass flow of the second OPF is located inside the first OPF and its outlet flow. This allows adjustment as an integral component without having to perform worst-case observations.

Advantageous further developments of the invention are specified in the dependent claims.

Thus, according to claims 2 and 3, the first and/or the second exhaust gas cleaning device can have a circular or non-circular cross-section and thus be adapted to the packaging.

In order to overcome thermal damage, according to claim 4, the exhaust funnel is supported in the perforation in the slide.

According to claim 5, a further improvement is achieved in that an exhaust pipe is provided in the perforation and a fibrous seal is provided between this exhaust pipe and the first exhaust gas purification device.

Preferably, according to claims 6 and 7, the first exhaust gas purification device and the second exhaust gas purification device are particulate filters or a combination of a particulate filter and a three-way catalytic converter or a combination of a particulate filter and an NSC catalytic converter or Combination of particulate filter and NOx storage catalyst.

Description of drawings

The invention is explained in more detail below with the aid of four figures.

FIG. 1 shows a plan view of an exhaust device according to the invention.

Figure 2 shows a vertical section of an exhaust device according to the invention.

Figure 3 shows a horizontal section of an exhaust device according to the invention.

Figure 4 again shows a vertical section of the exhaust device according to the invention.

Detailed ways

The same reference numerals apply to the same components below in FIGS. 1 to 4 .

FIG. 1 shows a plan view of an exhaust system 1 according to the invention. The exhaust pipe 10 from the internal combustion engine (not shown) opens into the first canning 9 . The flow direction of the exhaust gas is indicated by the arrow on the first sealing can 9 . In the flow direction of the exhaust gas, the first closure 9 opens into the second closure 8 and the exhaust gas then leaves the exhaust gas purification device through two exhaust pipes 10 . The first exhaust gas purification device 2 is provided in the first sealing tank 9 , and the second exhaust gas purification device 3 is provided in the second inclined sealing tank 8 . Instead of two exhaust pipes 10 , it is also possible to provide only one single exhaust pipe 10 .

FIG. 2 shows a vertical section of the exhaust device 1 according to the invention. The vertical section of the exhaust system 1 according to the invention shows how the first exhaust gas cleaning device 2 is arranged in the first capsule 9 and how the second exhaust gas cleaning device 3 is arranged in the second capsule 8 . The flow direction of the exhaust gas is again shown schematically by arrows. As already mentioned, the first exhaust gas purification device 2 is arranged upstream of the second exhaust gas purification device 3 in the flow direction of the exhaust gas. Exhaust gas can flow through the two exhaust gas cleaning devices 2 , 3 , wherein the second exhaust gas cleaning device 3 can be circulated by the exhaust gas. This is shown in FIG. 3 .

According to the invention, the first exhaust gas purification device 2 has perforations 4 for the exhaust gas in the flow direction of the exhaust gas. The perforations 4 are connected by means of an exhaust funnel 5 to the flow cross-section of the second exhaust gas purification device 3 to guide the exhaust gas. In this embodiment, the first and second exhaust gas purification devices 2, 3 have circular cross sections. In another embodiment, the first and/or the second exhaust gas cleaning device 2 , 3 can also have a non-circular cross-section, for example an oval shape.

Preferably, the exhaust funnel 5 is supported in said perforations in the slide, which counteracts thermal defects. In the present embodiment, an exhaust pipe 6 is provided in the through hole 4 , and a fibrous sealing member 7 is provided between the exhaust pipe 6 and the first exhaust gas purification device 2 .

Further, the first exhaust gas purification device 2 and the second exhaust gas purification device 3 are supported inside the insulating portion 11 in the first sealing pot 9 and the second sealing pot 8 . This especially prevents heat loss.

The first and second exhaust gas purification devices 2 , 3 are preferably particulate filters (in particular gasoline particulate filters (OPF)) or particulate filters and additional three-way catalytic converters or particulate filters and additional NSC catalytic converters Or a particulate filter and an additional NOx storage catalyst.

FIG. 3 shows a horizontal section of the exhaust device 1 according to the invention. The exhaust gas again flows through the exhaust pipe 10 from the internal combustion engine (not shown) and flows through the first exhaust gas purification device 2 and through the exhaust pipe 6 arranged in the bore 4 further into the exhaust funnel 5 and through the second exhaust gas purification device 3. In parallel with this, the exhaust gas flows into two exhaust pipes 10 (not shown) via the first exhaust gas purification device 2 and the second exhaust gas purification device 3 . It can also be clearly seen that the insulating portion 11 is radially outside the first exhaust gas purification device 2 and the second exhaust gas purification device 3 .

FIG. 4 shows a vertical section of the exhaust system 1 according to the invention shown in three dimensions. In FIG. 4 , the first sealing pot 9 and the second sealing pot 8 can again be seen, in which the first exhaust gas cleaning device 2 and the second exhaust gas cleaning device 3 are arranged. The exhaust gas flows again from the left not only through the first exhaust gas cleaning device 2 but also through an exhaust pipe 6 arranged in the bore 4 and arranged in the first exhaust gas cleaning device 2 by means of a fibrous seal 7 . After the exhaust pipe 6 , the exhaust gas flows again through the exhaust funnel 5 into the second exhaust gas purification device 3 . The first exhaust gas cleaning device 2 and the second exhaust gas cleaning device 3 are again supported in the insulation in the first sealing pot 9 and the second sealing pot 8 .

The design of the exhaust system 1 according to the invention makes it possible to increase the effective flow cross-sections of the first and second exhaust gas purification devices 2 , 3 with the same overall volume.

List of reference numbers:

1 Exhaust device

2 The first exhaust gas purification device

3 Second exhaust gas purification device

4 perforated

5 Exhaust funnel

6 exhaust pipe

7 fibrous seals

8 Second canister

9 The first jar

10 exhaust pipe

11 Insulation

Claims (7)

1. An exhaust system (1) for an internal combustion engine, wherein at least one first and one second exhaust gas purification device (2, 3) are provided in the exhaust system (1), wherein the first exhaust gas purification device (2) is arranged upstream of the second exhaust gas purification device (3) in the flow direction of the exhaust gas, and the two exhaust gas purification devices (2, 3) can be traversed by the exhaust gas, and the second exhaust gas purification device (3) can be circulated by the exhaust gas,

the exhaust gas purification device is characterized in that the first exhaust gas purification device (2) has a perforation (4) for the exhaust gas in the flow direction of the exhaust gas, which perforation is connected in a flow cross section of the second exhaust gas purification device (3) in a manner such that the exhaust gas is guided through an exhaust funnel (5).

2. An exhaust arrangement according to claim 1, characterized in that the first and/or the second exhaust gas cleaning device (2, 3) has a circular cross-section.

3. An exhaust arrangement according to claim 1, characterized in that the first and/or the second exhaust gas cleaning device (2, 3) has a non-circular cross-section.

4. An exhaust apparatus according to any of claims 1-3, characterized in that the exhaust funnel (5) is supported in the perforation (4) in a slide.

5. An exhaust arrangement according to claim 4, characterized in that an exhaust pipe (6) is arranged in the perforation (4) and a fibrous sealing (7) is arranged between the exhaust pipe (6) and the first exhaust gas cleaning device (2).

6. An exhaust arrangement according to any one of claims 1-5, characterized in that the first exhaust gas cleaning device (2) is a particle filter or a particle filter and an additional three-way catalyst or a particle filter and an additional NSC catalyst or a particle filter and an additional NOx storage catalyst.

7. An exhaust arrangement according to any one of claims 1-5, characterized in that the second exhaust gas cleaning device (3) is a particle filter or a particle filter and an additional three-way catalyst or a particle filter and an additional NSC catalyst or a particle filter and an additional NOx storage catalyst.

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