DE102012207827A1 - ABGASNACHBEHANDLUNGSSYSTEM AND METHOD FOR TREATMENT OF EXHAUST GAS - Google Patents

Abstract

In an exemplary embodiment of the invention, an exhaust aftertreatment system is provided that includes an inlet housing, an inlet in the inlet housing configured to receive an exhaust gas flow from an internal combustion engine, and an outlet in the inlet housing configured to direct the exhaust gas flow to a To conduct pollution reduction device. The system also includes a steering device coupled to an interior surface of the inlet housing, the steering device configured to receive the flow of exhaust gas from the inlet and direct the flow of exhaust gas uniformly through the outlet and to the pollution control device.

Description

FIELD OF THE INVENTION

Exemplary embodiments of the invention relate to internal combustion engines and more particularly to exhaust aftertreatment systems for internal combustion engines.

BACKGROUND

Manufacturers of internal combustion engines, particularly diesel engines, face the challenging task of meeting current and future emission standards for the release of nitrogen oxides, particularly nitrogen monoxide, as well as unburned and partially oxidized hydrocarbons, carbon monoxide, particulate matter and other pollutants. In order to reduce the pollutant emissions of an internal combustion engine, an exhaust aftertreatment system is used to reduce pollutants in the exhaust gas flowing from the engine.

Exhaust aftertreatment systems typically include one or more aftertreatment devices, such as oxidation catalysts, catalytic converters, mixer elements, and urea injectors. Variations in exhaust gas flow, such as a lack of uniform flow, may affect the performance of the aftertreatment system, thereby causing release of unwanted pollutants from the system. As emission standards become increasingly stringent, improving the uniformity and distribution of the exhaust flow as it enters and flows through the aftertreatment system is desirable in meeting these standards.

SUMMARY OF THE INVENTION

In an exemplary embodiment of the invention, an exhaust aftertreatment system is provided that includes an inlet housing, an inlet in the inlet housing configured to receive exhaust flow from an internal combustion engine, and an outlet in the inlet housing configured to direct exhaust flow to one Conduct pollutant reduction device. The system also includes a steering device coupled to an inner surface of the inlet housing, wherein the steering device is configured to receive the exhaust flow from the inlet and to uniformly direct the exhaust flow through the outlet and to the pollutant reduction device.

In another exemplary embodiment of the invention, there is provided a method of treating exhaust gas from an internal combustion engine, the method comprising the steps of: receiving an exhaust gas flow from the internal combustion engine via an inlet in a housing and directing the exhaust gas flow to form a uniform exhaust gas flow to an outlet of the housing. The method further includes directing the uniform exhaust gas flow to a pollutant reduction device.

The above features and advantages as well as other features and advantages of the invention will be readily apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, advantages and details are provided by way of example only in the following detailed description of embodiments, the detailed description of which refers to the drawings, in which:

1 Figure 3 is a schematic diagram of one embodiment of an engine system;

2 Fig. 11 is a detailed sectional view of one embodiment of an exhaust aftertreatment system;

3 Fig. 12 is a detailed sectional end view of an exemplary inlet housing; and

4 a sectional side view of the in 3 shown inlet housing is.

DESCRIPTION OF THE EMBODIMENTS

The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that in the drawings, like reference numerals indicate like or corresponding parts and features.

1 FIG. 12 is a schematic diagram of one embodiment of an engine system. FIG 100 , The engine system 100 has an internal combustion engine 102 , an exhaust system 104 and a motor controller 106 on. The exhaust system 104 has an exhaust manifold 108 , an exhaust aftertreatment device 110 and an exhaust pipe 112 on. cylinder 116 are in the internal combustion engine 102 placed, the cylinders take a combination of combustion air and fuel. The combustion air / fuel mixture is burned, resulting in a reciprocating motion of pistons (not shown) in the cylinders 116 are placed. The reciprocating motion of the pistons rotates a crankshaft (not shown) to drive power to a vehicle driveline (not shown) or a generator or other stationary receiver of such power (not shown) in the case of stationary application of the internal combustion engine 102 to deliver. The combustion of the air / fuel mixture causes a flow of exhaust gas 118 through the exhaust manifold 108 and in the exhaust aftertreatment device 110 wherein the exhaust aftertreatment device 110 an inlet housing 119 , a first catalyst treatment device such as an oxidation catalyst 120 , a mixer element 122 and a second catalytic treatment device 124 having. The exhaust aftertreatment device 110 reduces, oxidizes, catches or otherwise treats various regulated constituents of the exhaust gas 118 before its release to the atmosphere, as by a flow of reduced pollutants of the exhaust gas 126 is shown.

In addition, the exhaust aftertreatment device 110 and a fluid supply 125 Functional with a motor controller 106 coupled and are controlled by this. The motor controller 106 collects information regarding the operation of the internal combustion engine 102 from the sensors 128a - 128n such as temperature (intake system, exhaust system, engine coolant, ambient, etc.), pressure, exhaust gas flow rates, NOx concentrations, and as a result can adjust the amount of a fluid, such as urea, entering the mixer element 122 is injected.

The term "controller" as used herein refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated or group) and memory that executes one or more software or firmware programs, a combinatorial logic circuit and / or others suitable components that provide the described functionality. In an exemplary embodiment, the inlet housing decreases 119 the diesel exhaust flow 118 and leads them into the oxidation catalyst 120 to remove pollutants and comply with emission regulations. The inlet housing 119 improves the uniformity and distribution of the exhaust gas flow 118 when it flows into the oxidation catalyst to improve the performance of the aftertreatment system 110 to increase.

According to an exemplary embodiment of the invention shows 2 a detailed sectional view of the exhaust aftertreatment system 110 , The aftertreatment system 110 has the inlet housing 119 and a rigid canister 204 on. The aftertreatment system 110 takes the exhaust 118 from the internal combustion engine 102 which, in some embodiments, may include a forced entry system (eg, turbocharger). An exhaust gas flow 126 shows a flow from the rigid canister 204 after the pollutants have been removed. The inlet housing 119 has an inlet 210 , Steering devices 212 and an outlet 214 on. The inlet housing generates a uniform flow of exhaust gas 118 to flow into the rigid canister 204 ,

In one embodiment, the exhaust aftertreatment system 110 the oxidation catalyst 120 , the mixer element 122 and the second catalytic treatment device 124 up in the rigid canister 204 is supported. The exemplary components are configured to contain pollutants from the exhaust 118 to remove. The uniform flow of the exhaust gas 118 from the inlet housing 119 improves the performance of the various catalytic components ( 122 . 124 ) of the exhaust aftertreatment system 110 , For example, the steering devices cause 212 improved flow uniformity of the exhaust gas as it flows from the outlet 214 to an inlet side 218 of the oxidation catalyst 120 flows. The uniform flow of exhaust gas across the side 218 and by the oxidation catalyst 120 contemplate improved flow through the component as well as more efficient use of the catalyst compound (s) used in the pollution control device 110 is / are arranged. Further, by uniformly distributing the exhaust gas flow through the inlet side 218 essentially the entire body of the diesel oxidation catalyst 120 used, whereby a pollutant reduction and flow are improved through and allows the internal combustion engine 102 Emission regulations fulfilled.

3 FIG. 12 is a detailed sectional end view of the exemplary inlet housing. FIG 119 , The inlet housing 119 may be of any suitable configuration and geometry to enhance uniformity of exhaust flow, such as the elliptical shape shown. The steering devices 212 are curved steering devices that are in relation to the inlet 210 and the incoming flow of exhaust gas 118 are oriented. As shown, the steering devices extend substantially perpendicularly from an inner surface 299 the Wall 300 of the inlet housing 119 , In embodiments, the inlet housing has one or more steering devices 212 up, extending from the wall 300 extend. In addition, a side wall extends 302 just as essentially perpendicular to the wall 300 wherein an outer wall of the inlet housing 119 is formed. In the embodiment shown, a steering device extends 304 from the inner surface 301 the side wall 302 to a flow in the inlet housing 119 continue to control. The steering devices 212 and 304 may be any suitable shape and orientation for flow control, such as curved or rectilinear elements related to the flow of exhaust gas 118 and / or the flow in the rigid canister 204 and oxidation catalyst 120 are aligned. The steering devices 212 and 304 may also be aligned or unoriented, and / or similar or different geometries and / or sizes, depending on the flow characteristics. The inlet housing 119 can be formed by any suitable method, such as stamping or casting. The steering devices 212 and 304 are formed by a suitable method, such as stamping with the inlet housing 119 or welding / brazing the steering devices 212 and 304 On Wall 300 , the inlet housing 119 includes a suitable durable material capable of withstanding high temperatures, such as a metal alloy (eg, steel alloys or stainless steel).

4 is a sectional side view of the inlet housing 119 , As shown, the exhaust gas flows 118 in the inlet 210 and gets through the steering devices 212 controlled and redirected. The steering devices 212 are arranged such that a uniform exhaust gas flow 400 through the outlet 214 in the substrate of the oxidation catalyst 120 is effected in the rigid canister 204 is supported. In one embodiment, the steering devices 212 with the surface via couplings 402 coupled, which may be any suitable coupling. For example, the couplings 402 a Hartlötstelle, weld or other adhesive bond to the steering devices 212 on the wall 300 to install. As in the 1 - 4 3, exemplary embodiments of the inlet housing are shown 119 an improved uniformity of the exhaust gas flow 118 in the exhaust aftertreatment system 110 in front. The improved flow uniformity improves the performance of the aftertreatment system 110 , In one embodiment, the improved uniformity of the exhaust flow 400 at the outlet 214 of the inlet housing 119 characterized by a flow uniformity index of about 0.80 to about 0.90. In other embodiments, the flow uniformity index is greater than about 0.90. The flow uniformity index is widely used in the automotive industry to interpret the degree of flow distribution at the front of a substrate, and in one embodiment is defined as follows:

Other values are as follows: U = instantaneous speed at the side of a local area; U _avg = average speed across the side where the flow _{uniformity index is} studied; Φ = absolute difference between the current and the average speed (always a positive value); and A ₀ = total area over which the flow uniformity index is examined. As defined above, the uniformity can be as high as 1.0, indicating a perfectly distributed flow. Higher uniformity index (near 1.0 is generally an indication of a better uniformly distributed flow).

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention, but that the invention encompass all embodiments falling within the scope of the present application.

Claims (10)

Exhaust after-treatment system comprising: an inlet housing; an inlet in the inlet housing configured to receive an exhaust flow from an internal combustion engine; an outlet in the inlet housing configured to direct the exhaust gas flow to a pollutant reduction device disposed in the exhaust aftertreatment system; and a steering device coupled to an inner surface of the inlet housing, the steering device configured to receive the exhaust flow from the inlet and uniformly direct the exhaust flow through the inlet and to the pollutant reduction device. The system of claim 1, comprising a plurality of steering devices extending substantially perpendicularly from the inner surface, wherein the plurality of steering devices comprise curved elements. The system of claim 1, including a side guide extending from a side wall of the elliptically shaped housing. The system of claim 1, wherein the housing comprises a housing of elliptical shape. The system of claim 1, wherein a first exhaust gas flow direction through the inlet is substantially perpendicular to a second exhaust gas flow direction through the outlet. The system of claim 1, wherein the steering device is configured to uniformly direct exhaust gas flow through the outlet with a uniformity index greater than about 0.85. A method of treating exhaust gas from an internal combustion engine, the method comprising: Receiving an exhaust gas flow from the internal combustion engine via an inlet in a housing; Directing the exhaust gas flow to form a uniform flow of exhaust gas to an outlet of the housing; and Passing the uniform exhaust gas flow to a pollutant reduction device. The method of claim 7, wherein directing the flow of exhaust gas includes directing the flow of exhaust gas across a plurality of steering devices that extend at right angles from an interior surface of the housing. The method of claim 8, wherein directing the exhaust gas flow comprises directing the flow of exhaust gas across a side deflector extending from a side wall of the housing. The method of claim 8, wherein directing the exhaust gas flow comprises directing the exhaust gas flow over the plurality of steering devices comprising a plurality of curved elements.

Images