DE102014202727A1 - CATALYST ARRANGEMENT - Google Patents

Abstract

A catalyst assembly (20) for an internal combustion engine, the catalyst assembly comprising: a catalyst housing (21) configured to house a catalyst, and an outlet housing (22) including an outlet (23) of the catalyst assembly and configured to that one end (21b) of the catalyst housing extends into a chamber (26) defined by the outlet housing, the outlet being set back from the end of the catalyst housing so that, in use, exhaust gases flowing through the outlet housing over at least a portion of an outwardly facing surface ( 27) of the catalytic converter housing.

Description

The present disclosure relates to a catalyst assembly for an internal combustion engine.

Exhaust systems for automotive internal combustion engines usually include a catalytic converter. The catalyst includes a catalyst insert that reduces engine-out lean emissions by converting such emissions into less harmful materials by a catalyzed chemical reaction.

Usually, a catalyst must reach a certain temperature before it can operate effectively. This temperature is referred to as "light-off temperature". Therefore, catalysts can be tightly coupled to an exhaust of the engine to save time in achieving the light-off temperature and, in the meantime, reduce drag emissions.

In automotive applications, however, there is usually little space available near the engine; It may be necessary to compromise on the proximity of the catalyst to the exhaust of the engine.

In addition, the arrangement of an exhaust system comprising the catalyst is usually designed specifically for a particular application, such as a particular motor vehicle model. Due to the special design required for such systems and the consequent increase in component inventory, this is undesirable.

The present disclosure is intended to overcome these problems.

According to a first aspect of the present invention, there is provided a catalyst assembly for an internal combustion engine, the catalyst assembly comprising: a catalyst housing configured to house a catalyst and an outlet housing including an outlet of the catalyst assembly and configured to be one End of the catalyst housing extends into a chamber defined by the outlet housing, wherein the outlet is at least partially set back from the end of the catalyst housing, so that flowing through the exhaust housing exhaust gases in use flow over at least a portion of an outwardly facing surface of the catalyst housing.

The catalyst assembly may further include a spray injector. The spray injector may be configured to inject a spray into the outlet housing chamber. The spray injector may be configured to inject urea into the outlet housing chamber.

The catalyst housing and the outlet housing may define a ring in an area where the catalyst housing and the outlet housing may overlap. For example, an inner wall of the outlet housing and an outer wall of the catalyst housing may define the ring. Although the catalyst housing and the outlet housing may be substantially cylindrical, but also have any other shape. A cross-sectional area of the ring may substantially correspond to a cross-sectional area of the catalyst.

The outlet may be provided in the area where the catalyst housing and the outlet housing overlap, for example, such that the outlet is in fluid communication with the ring. The outlet may be provided in an outer wall of the outlet housing.

The outlet housing may carry exhaust flow from the catalyst through the outlet. The outlet housing may comprise an end wall. The end wall may include an opening for receiving the end of the catalyst housing extending into the outlet housing chamber. The end wall can be arranged next to the ring. The end wall may be recessed from the end of the catalyst housing.

The catalyst assembly may be configured to be closely coupled to the internal combustion engine. The catalyst assembly may be closely coupled to an engine associated outlet, such as an engine exhaust manifold or turbocharger outlet.

An exhaust system for an internal combustion engine may include the above catalyst arrangement.

The exhaust system may further include an exhaust purification system. The exhaust purification assembly may be configured for placement downstream of the catalyst assembly.

The exhaust system may further include a connection pipe. The connecting tube may be configured for placement between the outlet of the catalyst assembly and the exhaust purification assembly.

The exhaust gas purification arrangement may comprise a further catalyst. The exhaust purification system may include a diesel particulate filter. The exhaust gas purification arrangement can Include selective catalytic reduction system. The exhaust purification system may include a combination of a selective catalytic reduction system and a diesel particulate filter. The exhaust gas purification arrangement may comprise any combination of the above-mentioned components.

The exhaust gas purification arrangement may be adjustable in size, for example in length. The exhaust gas purifier assembly may be tailored to a particular application.

The exhaust system may further include a urea dosing unit. The urea dosing unit may be coupled to the outlet housing to dispense urea into the outlet housing chamber.

The exhaust system can be modular. One or more components of the exhaust system may be common to different vehicle platforms.

For a better understanding of the present disclosure and to clarify its embodiment, reference will now be made by way of example to the accompanying drawings. Show it:

1 an exhaust system according to an example of the present disclosure,

2a and 2 B Side sectional views of a catalyst assembly according to an example of the present disclosure with or without spray injectors and

3 an end sectional view of a catalyst assembly according to an example of the present disclosure.

With reference to 1 The present disclosure relates to an exhaust system 10 for a motor vehicle, in particular for an internal combustion engine of a motor vehicle. In a specific example, the present disclosure may be applied to a diesel engine, although it may equally be applied to a gasoline engine or any other type of engine. The exhaust system 10 includes a catalyst arrangement 20 , As shown, the exhaust system 10 Furthermore, an exhaust gas purification arrangement 40 include, downstream of the catalyst assembly 20 can be placed.

Between the catalyst arrangement 20 and the exhaust purification device 40 can be a connecting pipe 50 be provided. It is understood that exhaust gases from the internal combustion engine (eg, from the exhaust manifold or turbocharger, not shown) via an inlet 24 in the catalyst arrangement 20 and then over the connecting pipe 50 in the exhaust gas purification arrangement 40 can flow. The exhaust gases from the exhaust gas purification arrangement 40 may be from an exhaust gas purifier assembly outlet 42 be delivered. The exhaust gases can then z over other pipes, not shown. B. are issued from the motor vehicle.

The catalyst arrangement 20 may include a catalyst cartridge, not shown, that is configured to convert engine emissions to less harmful materials by a catalyzed chemical reaction. For example, the catalyst may convert carbon monoxide to carbon dioxide, unburned hydrocarbons to carbon dioxide and water or nitrogen oxides to nitrogen, and / or to carry out any combination of these reactions. However, in one particular arrangement, the catalyst may convert carbon monoxide to carbon dioxide and / or unburned hydrocarbons to carbon dioxide and water. A catalyst insert of the catalyst may be provided on a honeycomb structure, which may be ceramic or metallic. The catalyst insert may comprise platinum, palladium, rhodium, cerium, iron, manganese, nickel, copper or any other suitable material or combination thereof.

The exhaust gas purification arrangement 40 may comprise a further catalyst. With respect to the catalyst described features may equally apply to the other catalyst. In particular, the exhaust gas purification arrangement 40 a catalyst for converting nitrogen oxides into nitrogen or nitrogen and water. For example, the exhaust gas purification system may include a selective catalytic reduction system.

In addition or as an alternative to the further catalyst, the exhaust gas purification arrangement 40 include a diesel particulate filter. In a specific example, the exhaust purification system 40 a combination of a selective catalytic reduction system and a diesel particulate filter in which, for example, the selective catalytic reduction system may be provided on a surface of the diesel particulate filter.

The exhaust system 10 can be modular. For example, the catalyst arrangement 20 and / or the exhaust gas purification arrangement 40 be common to different vehicle platforms. In this way the design and validation effort can be reduced and stock levels can be minimized. By sharing the functions of the catalyst and the exhaust gas purifying arrangement, moreover, a more adaptable exhaust system can be provided.

The exhaust gas purification arrangement 40 However, it can be adjustable in size, for example in length. For example, various exhaust gas purifying arrangements 40 be provided, which may differ in length. The exhaust gas purification arrangements may differ only in length. In this way, the exhaust gas purification arrangement can be adapted to a specific application, eg. B. tailored to a particular model of motor vehicle. The design and validation of a longer or shorter exhaust purification arrangement can be easily accomplished, and the delivery and storage of different length exhaust purification arrangements can be readily possible.

The connecting pipe 50 can be applied to a specific application, eg. As a special model of motor vehicle, are tailored. The design of a connection pipe for a particular application may be less expensive than designing specific catalysts for each automotive model. Compared to special catalytic converters for each motor vehicle model, it can also be easier to supply different connecting tubes and to carry them in the warehouse.

Regarding 2 and 3 includes the catalyst arrangement 20 a catalyst housing 21 and an outlet housing 22 that has an outlet 23 the catalyst assembly comprises. As mentioned above, the catalyst arrangement 20 comprise a catalyst, and the catalyst housing 21 can accommodate the catalyst 19 be configured. The outlet housing 22 Can the exhaust gas flow from the catalyst 19 through the outlet 23 to lead.

The catalyst arrangement 20 may be configured to be closely coupled to the engine. The catalyst arrangement 20 may be closely coupled to an engine associated outlet, such as an engine exhaust manifold or turbocharger outlet.

The catalyst arrangement 20 can the inlet 24 include that in an input cone 25 can be provided. The input cone 25 can be at an inlet end 21a the catalyst housing 21 be coupled. The input cone 25 may be the cross-sectional area of the flow from the inlet 24 to the inlet end 21a increase the catalyst housing.

As shown, an outlet end may 21b the catalyst housing 21 in one through the outlet housing 22 defined chamber 26 extend. Accordingly, the outlet housing 22 at least where it is with the catalyst housing 21 overlapped, larger than this, for example, it may have a larger diameter. The outlet 23 can be at least partially from the outlet end 21b the catalyst housing 21 to be back. For example, a section of the outlet 23 defining opening from the outlet end 21b the catalyst housing 21 to be back. As an alternative, the entire outlet 23 defining opening from the outlet end 21b the catalyst housing 21 to be back.

Accordingly, it is understood that exhaust gases in use through the outlet housing 22 flow through one through the catalyst housing 21 and the outlet housing 22 defined ring 31 flow (as indicated by the arrows in 2a and 2 B indicated). The exhaust gases may extend over at least a portion of an outwardly facing surface 27 the catalyst housing 21 stream.

The outlet housing 22 can be a first end wall 28a include. The first end wall 28a may be to a longitudinal axis of the catalyst housing 21 be substantially perpendicular or the first end wall 28a can, as shown, with respect to the longitudinal axis of the catalyst housing 21 be angled. The first end wall 28a can an opening 29 for receiving the outlet end 21b the catalyst housing 21 include, located in the outlet housing chamber 26 extends. In other words, the catalyst housing can 21 through the opening 29 in the first end wall 28a extend. The end wall 28a can from the outlet end 21b the catalyst housing 21 to be back.

The outlet housing 22 can have a second end wall 28b include. The second end wall 28b can be over one end of an outlet housing 22 extend. The second end wall 28b It can be rounded where it attaches to the rest of the outlet housing 22 followed. The second end wall 28b , z. B. the rounded edge, can flow from the catalyst to that of the catalyst housing 21 and the outlet housing 22 defined ring 31 to lead.

Between the catalyst 19 and the catalyst housing 21 can be a topping 18 be provided. The surface 18 can from the inlet end 21a or the outlet end 21b the catalyst housing 21 or be retarded by both.

In 2 B can the catalyst arrangement 20 also a spray injector 30 include, which is shown schematically. The spray injector 30 may be configured to spray, e.g. As a spray of liquid droplets, in the outlet housing chamber 26 inject. In a specific example, the spray injector 30 be configured to inject urea into the outlet housing chamber. Injection of urea may occur in a selective catalytic reduction reaction in the exhaust gas purification system 40 be used. Accordingly, it is understood that the exhaust system 10 may further comprise a urea dosing unit, not shown. The urea dosing unit can be attached to the outlet housing 22 coupled to deliver urea into the outlet housing chamber. Injecting a spray into the outlet housing chamber 26 For example, thanks to the turning of the flow and / or any turbulence in this area, it may lead to increased mixing of the spray with the exhaust gases.

As in 3 shown, the catalyst housing 21 and the outlet housing 22 in an area where the catalyst housing and the outlet housing may overlap, the ring 31 define. For example, an inner wall 32 of the outlet housing 22 and the outward-facing surface 27 the catalyst housing 21 The ring 31 define. As shown, the catalyst housing 21 and the outlet housing 22 at least in the area of the ring 31 may be substantially cylindrical, although they may have any other shape. The catalyst housing 21 and the outlet housing 22 can be at least in the area of the ring 31 be essentially concentric.

The outlet 23 may be provided in the area in which the catalyst housing 21 and the outlet housing 22 overlap. Therefore, the outlet 23 with the ring 31 in fluid communication. The outlet 23 can in the outer wall 33 of the outlet housing 22 be provided. The outlet 23 can with the connecting pipe 50 the exhaust system 10 be connected.

The cross-sectional area 34 of the ring 31 can be essentially equal to a cross-sectional area 35 of the catalyst. In this way, the flow of exhaust gas through the outlet housing by flowing into the ring 31 not unduly disturbed, and a pressure drop across the catalyst assembly 20 can be minimized.

The outlet housing of the present disclosure may have a shorter catalyst arrangement 20 be possible without a pressure loss over the catalyst assembly is necessarily affected. This can be achieved by the cross-sectional area of the ring and / or the increased residence time of the exhaust gas flow in the outlet housing.

It is understood that a shorter catalyst arrangement can be used in a wider range of applications, especially in applications where there is little space near the motor. Therefore, the same catalyst arrangement 20 in various applications, eg. B. in various motor vehicle models, are used. In this way the design and validation effort can be reduced and stock levels can be minimized.

Furthermore, it can be ensured by the direct flow of the exhaust gases from the engine into the catalyst that the light-off temperature of the catalyst is reached quickly. Heat from the exhaust gases can also be recovered by the flow of the exhaust gases over the outward-facing surface of the catalyst housing, which helps to warm the catalyst up more quickly. In other words, heat from the exhaust gases may be transferred to the catalyst through the catalyst housing where it overlaps the exhaust housing.

Claims (20)

Catalyst arrangement for an internal combustion engine, the catalyst arrangement comprising: a catalyst housing configured to house a catalyst, and an outlet housing including an outlet of the catalyst assembly and configured to extend one end of the catalyst housing into a chamber defined by the outlet housing, wherein the outlet is at least partially recessed from the end of the catalyst housing such that exhaust gases flowing through the outlet housing in use flow over at least a portion of an outwardly facing surface of the catalyst housing. The catalyst assembly of claim 1, wherein the catalyst assembly further comprises a spray injector configured to inject a spray into the outlet housing chamber. The catalyst assembly of claim 2, wherein the spray injector is configured to inject urea into the outlet housing chamber. A catalyst assembly according to any one of the preceding claims, wherein the catalyst housing and the outlet housing define a ring in an area where the catalyst housing and the outlet housing overlap. Catalyst arrangement according to claim 4, wherein a cross-sectional area of the ring substantially corresponds to a cross-sectional area of the catalyst. Catalyst arrangement according to claim 4 or 5, wherein the outlet is provided in the region in which the catalyst housing and the Overlap the outlet housing so that the outlet is in fluid communication with the ring. Catalyst arrangement according to one of the preceding claims, wherein the outlet is provided in an outer wall of the outlet housing. The catalyst assembly of any one of the preceding claims, wherein the outlet housing includes an end wall including an opening for receiving the end of the catalyst housing extending into the outlet housing chamber. Catalyst arrangement according to one of the preceding claims, wherein the catalyst arrangement is configured to be closely coupled to the internal combustion engine. Exhaust system for an internal combustion engine, wherein the exhaust system comprises the catalyst arrangement according to one of the preceding claims. The exhaust system of claim 10, wherein the exhaust system further includes an exhaust purification assembly configured to be placed downstream of the catalyst assembly. The exhaust system of claim 11, wherein the exhaust system further comprises a connection tube configured for placement between the outlet of the catalyst assembly and the exhaust purification assembly. Exhaust system according to claim 11 or 12, wherein the exhaust gas purification arrangement comprises a further catalyst. The exhaust system of any one of claims 11 to 13, wherein the exhaust purification system comprises a diesel particulate filter. The exhaust system of any one of claims 11 to 14, wherein the exhaust purification system comprises a selective catalytic reduction system. The exhaust system of any one of claims 11 to 15, wherein the exhaust gas purification assembly comprises a combination of a selective catalytic reduction system and a diesel particulate filter. An exhaust system according to any one of claims 11 to 16, wherein the exhaust gas purification arrangement is adjustable in size. The exhaust system of any one of claims 10 to 17, wherein the exhaust system further comprises a urea dosing unit coupled to the outlet housing of the catalyst assembly for discharging urea into the outlet housing chamber. The exhaust system of any one of claims 11 to 18, wherein the exhaust system is modular, wherein one or more components of the exhaust system are common to different vehicle platforms. Catalyst arrangement or exhaust system as described herein with reference to the accompanying drawings and shown there.

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