US20110296820A1

US20110296820A1 - Engine exhaust gas treatment device including electrically actuated hydrocarbon adsorber bypass valve

Info

Publication number: US20110296820A1
Application number: US12/791,919
Authority: US
Inventors: Halim G. Santoso; Randy L. Dufresne
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2010-06-02
Filing date: 2010-06-02
Publication date: 2011-12-08
Also published as: DE102011102631A1; CN102278175A

Abstract

An engine exhaust gas treatment device may include a housing, a hydrocarbon adsorber, an adsorber bypass passage, and a bypass valve assembly. The hydrocarbon adsorber may be located within the housing and may define a first flow path between an exhaust gas inlet and an exhaust gas outlet of the housing. The adsorber bypass passage may define a second flow path between the exhaust gas inlet and the exhaust gas outlet. The bypass valve assembly may include a bypass valve and an electric actuation mechanism engaged with the bypass valve. The bypass valve may be displaceable between open and closed positions by the electric actuation mechanism.

Description

FIELD

The present disclosure relates to engine exhaust systems, and more specifically, engine exhaust gas treatment devices including hydrocarbon adsorbers.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.
Engine emissions standards include limits on hydrocarbon emissions. Hydrocarbon emissions may be difficult to treat at cold start operating conditions due to available temperature of catalysts used to treat hydrocarbon emissions. Engine exhaust gas treatment devices may include a hydrocarbon adsorber to trap hydrocarbon emissions during cold operation and treat the hydrocarbon emissions once the catalyst reaches an operating temperature.

SUMMARY

An engine exhaust gas treatment device may include a housing, a hydrocarbon adsorber, an adsorber bypass passage, and a bypass valve assembly. The housing may define an exhaust gas inlet and an exhaust gas outlet. The hydrocarbon adsorber may be located within the housing between the exhaust gas inlet and the exhaust gas outlet and may define a first flow path between the exhaust gas inlet and the exhaust gas outlet. The adsorber bypass passage may be defined within the housing between the exhaust gas inlet and the exhaust gas outlet and may define a second flow path between the exhaust gas inlet and the exhaust gas outlet. The first and second flow paths may form parallel flow paths between the exhaust gas inlet and the exhaust gas outlet. The bypass valve assembly may include a bypass valve and an electric actuation mechanism engaged with the bypass valve. The bypass valve may be located within the housing and may be displaceable between open and closed positions by the electric actuation mechanism. The bypass valve may provide communication between the exhaust gas inlet and the exhaust gas outlet through the adsorber bypass passage when in the open position and may inhibit communication between the exhaust gas inlet and the exhaust gas outlet through the adsorber bypass passage when in the closed position.
An adsorber bypass conduit may extend through the hydrocarbon adsorber and may define the adsorber bypass passage.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a schematic illustration of a vehicle according to the present disclosure;

FIG. 2 is perspective section view of an engine exhaust gas treatment device shown in FIG. 1; and

FIG. 3 is an additional perspective section view of the engine exhaust gas treatment device shown in FIG. 1.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Examples of the present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
When an element or layer is referred to as being “on,” “engaged to,” “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
As used herein, the term “module” refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, or other suitable components that provide the described functionality.
Referring to FIG. 1, an exemplary vehicle 10 may include an engine assembly 12, a transmission 14, a driveline assembly 16, an exhaust assembly 18, and a control module 20. The engine assembly 12 may include an internal combustion engine 22 having a crankshaft 24 rotationally driven by pistons 26, an intake manifold 28 providing an air flow (A) to the engine 22 and exhaust manifolds 30, 32 receiving exhaust gas (E) exiting the engine 22. The driveline assembly 16 may include an output shaft 34 and a drive axle 36. The engine 22 may be coupled to the transmission 14 to drive the output shaft 34 and power rotation of the drive axle 36.
The exhaust assembly 18 may include an engine exhaust gas treatment device 40 in communication with the exhaust manifolds 30, 32 via an exhaust gas conduit 42. With reference to FIGS. 2 and 3, the engine exhaust gas treatment device 40 may include a housing 44, a hydrocarbon adsorber 46, an adsorber bypass conduit 48, a catalyst member 50, and a bypass valve assembly 52. The housing 44 may define an exhaust gas inlet 54 and an exhaust gas outlet 56 and may include a nozzle 58 at the exhaust gas inlet 54. The hydrocarbon adsorber 46 may be located within the housing 44 between the exhaust gas inlet 54 and an exhaust gas outlet 56 forming a first flow path between the exhaust gas inlet 54 and the exhaust gas outlet 56. By way of non-limiting example, the hydrocarbon adsorber 46 may be formed from a zeolite material. In the present non-limiting example, the zeolite material may be for treatment of ethanol emissions. The catalyst member 50 may include a three-way catalyst.
The adsorber bypass conduit 48 may extend through the hydrocarbon adsorber 46 and define an adsorber bypass passage 60. The adsorber bypass passage 60 defines a second flow path between the exhaust gas inlet 54 and the exhaust gas outlet 56 parallel to the first flow path defined through the hydrocarbon adsorber 46. The first flow path may generally form an annular flow path surrounding the second flow path.
The catalyst member 50 may be located between the hydrocarbon adsorber 46 and the adsorber bypass conduit 48 and the exhaust gas outlet 56. The catalyst member 50 may receive exhaust gas exiting the hydrocarbon adsorber 46 and/or the adsorber bypass conduit 48 depending on the position of the bypass valve assembly 52 as discussed below.
The bypass valve assembly 52 may include an electrically actuated bypass valve 62 located in the adsorber bypass passage 60 and an electric actuation mechanism 64 engaged with the electrically actuated bypass valve 62 to displace the electrically actuated bypass valve 62 between a closed position (FIG. 2) and an open position (FIG. 3). The electrically actuated bypass valve 62 provides communication between the exhaust gas inlet 54 and the exhaust gas outlet 56 when in the open position and inhibits (or prevents) communication between the exhaust gas inlet 54 and the exhaust gas outlet 56 when in the closed position.
The nozzle 58 may form a converging nozzle including a nozzle outlet 66 defining a first inner diameter (D1). The nozzle outlet 66 may be located adjacent to an inlet 68 of the adsorber bypass passage 60 defined at an end 70 of the adsorber bypass conduit 48. The nozzle outlet 66 and the inlet 68 of the adsorber bypass passage 60 may define a spacing therebetween. The nozzle outlet 66 may be concentrically aligned with the inlet 68 of the adsorber bypass passage 60.
The inlet 68 of the adsorber bypass passage 60 may define a second inner diameter (D2). The first inner diameter (D1) may be less than the second inner diameter (D2). By way of non-limiting example, the first inner diameter (D1) may be eighty percent to ninety-nine percent of the second inner diameter (D2), and more specifically eighty percent to ninety-five percent of the second inner diameter (D2). The nozzle outlet 66 may also be axially spaced a distance (L) from the inlet 68 of the adsorber bypass passage 60. In the present non-limiting example, the nozzle outlet 66 is axially spaced less than ten millimeters from the inlet 68 of the adsorber bypass passage 60. The difference between the first and second inner diameters (D1, D2) and/or distance (L) may form the spacing between the nozzle outlet 66 and the inlet 68 of the adsorber bypass passage 60.
The end 70 of the adsorber bypass conduit 48 defining the inlet 68 may extend axially outward from the hydrocarbon adsorber 46 in a direction from the exhaust gas outlet 56 toward the exhaust gas inlet 54. The housing 44 may define an annular chamber 72 surrounding the adsorber bypass conduit 48 at a location axially between the inlet 68 of the adsorber bypass passage 60 and the hydrocarbon adsorber 46. The annular chamber 72 may be in communication with the exhaust gas inlet 54 through the spacing defined between the nozzle outlet 66 and the inlet 68 of the adsorber bypass passage 60.
The control module 20 may be in communication with the electric actuation mechanism 64 to displace the electrically actuated bypass valve 62 between the closed position (FIG. 2) and the open position (FIG. 3). When the electrically actuated bypass valve 62 is in the closed position (FIG. 2), the exhaust gas may flow through the hydrocarbon adsorber 46 in a first direction (A1) from the exhaust gas inlet 54 to the exhaust gas outlet 56. The exhaust gas may flow from the exhaust gas inlet 54 through the hydrocarbon adsorber 46 to the catalyst member 50 and out the exhaust gas outlet 56. The housing 44 may include a diffuser 74 between the hydrocarbon adsorber 46 and the catalyst member 50 and defining openings 76 to control exhaust flow rate through the hydrocarbon adsorber 46.
When the electrically actuated bypass valve 62 is in the open position (FIG. 3), the exhaust gas may flow through the hydrocarbon adsorber 46 in a second direction (A2) opposite the first direction (A1) and from the exhaust gas outlet 56 to the exhaust gas inlet 54. The exhaust gas flows through the adsorber bypass passage 60 in the first direction (A1) to the catalyst member 50 and out the exhaust gas outlet 56. The exhaust gas flow through the hydrocarbon adsorber 46 in the second direction (A2) may be generated by the arrangement between the nozzle outlet 66 and the inlet 68 of the adsorber bypass conduit 48. More specifically, the spacing between the nozzle outlet 66 and the inlet 68 of the adsorber bypass conduit 48 may create a localized low pressure region within the annular chamber 72. As a result, a portion of the exhaust gas may flow from the higher pressure region of the housing 44 between the hydrocarbon adsorber 46 and the catalyst member 50 through the hydrocarbon adsorber 46 in the second direction (A2). The exhaust gas may flow to the adsorber bypass conduit 48 through the spacing defined between the nozzle outlet 66 and the inlet 68 of the adsorber bypass conduit 48.

Claims

1. An engine exhaust gas treatment device comprising:

a housing defining an exhaust gas inlet and an exhaust gas outlet;

a hydrocarbon adsorber located within the housing between the exhaust gas inlet and the exhaust gas outlet and defining a first flow path between the exhaust gas inlet and the exhaust gas outlet;

an adsorber bypass passage within the housing between the exhaust gas inlet and the exhaust gas outlet and defining a second flow path between the exhaust gas inlet and the exhaust gas outlet, the first and second flow paths forming parallel flow paths between the exhaust gas inlet and the exhaust gas outlet; and

a bypass valve assembly including a bypass valve and an electric actuation mechanism engaged with the bypass valve, the bypass valve located within the housing and displaceable between open and closed positions by the electric actuation mechanism, the bypass valve providing communication between the exhaust gas inlet and the exhaust gas outlet through the adsorber bypass passage when in the open position and inhibiting communication between the exhaust gas inlet and the exhaust gas outlet through the adsorber bypass passage when in the closed position.

2. The engine exhaust gas treatment device of claim 1, wherein the exhaust gas inlet of the housing includes a nozzle having a nozzle outlet located adjacent an inlet of the adsorber bypass passage, the nozzle outlet and the inlet of the adsorber bypass passage defining a spacing therebetween.

3. The engine exhaust gas treatment device of claim 2, wherein the nozzle outlet has a first inner diameter less than a second inner diameter of the inlet of the adsorber bypass passage.

4. The engine exhaust gas treatment device of claim 3, wherein the nozzle outlet is axially spaced from the inlet of the adsorber bypass passage.

5. The engine exhaust gas treatment device of claim 4, wherein the nozzle outlet is axially spaced less than 10 millimeters from the inlet of the adsorber bypass passage.

6. The engine exhaust gas treatment device of claim 4, wherein the nozzle outlet and the inlet of the adsorber bypass passage are concentrically aligned with one another.

7. The engine exhaust gas treatment device of claim 3, wherein the first inner diameter is between 80 percent and 95 percent of the second inner diameter.

8. The engine exhaust gas treatment device of claim 2, wherein the adsorber bypass passage is formed by an adsorber bypass conduit defining the inlet of the adsorber bypass passage and extending axially beyond the hydrocarbon adsorber toward exhaust gas inlet.

9. The engine exhaust gas treatment device of claim 8, wherein the housing defines an annular chamber surrounding the adsorber bypass conduit at a location axially between the inlet of the adsorber bypass passage and the hydrocarbon adsorber.

10. The engine exhaust gas treatment device of claim 9, wherein the annular chamber is in communication with the exhaust gas inlet through the spacing between the nozzle outlet and the inlet of the adsorber bypass passage.

11. The engine exhaust gas treatment device of claim 10, wherein the annular chamber operates at a first pressure less than a second pressure within the housing at an outlet of the adsorber bypass passage when the bypass valve is in the open position, an exhaust gas provided to the engine exhaust gas treatment device flowing in a first direction from the exhaust gas inlet to the exhaust gas outlet through the adsorber bypass passage and flowing in a second direction from the exhaust gas outlet to the exhaust gas inlet through the hydrocarbon adsorber when the bypass valve is in the open position, the exhaust gas flowing through the hydrocarbon adsorber in the first direction when the bypass valve is in the closed position.

12. The engine exhaust gas treatment device of claim 1, wherein the first flow path is an annular flow path surrounding the second flow path.

13. The engine exhaust gas treatment device of claim 1, wherein the hydrocarbon adsorber is formed from a zeolite for treatment of ethanol emissions.

14. The engine exhaust gas treatment device of claim 1, further comprising a catalyst member located within the housing between the hydrocarbon adsorber and the exhaust gas outlet.

15. An engine exhaust gas treatment device comprising:

a housing defining an exhaust gas inlet and an exhaust gas outlet;

an adsorber bypass conduit extending through the hydrocarbon adsorber and defining a second flow path between the exhaust gas inlet and the exhaust gas outlet, the first and second flow paths forming parallel flow paths between the exhaust gas inlet and the exhaust gas outlet; and

a bypass valve assembly including a bypass valve and an electric actuation mechanism engaged with the bypass valve, the bypass valve located within the housing and displaceable between open and closed positions by the electric actuation mechanism, the bypass valve providing communication between the exhaust gas inlet and the exhaust gas outlet through the adsorber bypass conduit when in the open position and inhibiting communication between the exhaust gas inlet and the exhaust gas outlet through the adsorber bypass conduit when in the closed position.

16. The engine exhaust gas treatment device of claim 15, wherein the exhaust gas inlet of the housing includes a nozzle having a nozzle outlet located adjacent an inlet of the adsorber bypass conduit, the nozzle outlet and the inlet of the adsorber bypass conduit defining a spacing therebetween.

17. The engine exhaust gas treatment device of claim 16, wherein the nozzle outlet has a first inner diameter less than a second inner diameter of the inlet of the adsorber bypass conduit and the nozzle outlet is axially spaced from the inlet of the adsorber bypass conduit.

18. The engine exhaust gas treatment device of claim 17, wherein the nozzle outlet is axially spaced less than 10 millimeters from the inlet of the adsorber bypass conduit and the first inner diameter is between 80 percent and 95 percent of the second inner diameter.

19. The engine exhaust gas treatment device of claim 18, wherein the housing defines an annular chamber surrounding the adsorber bypass conduit at a location axially between the inlet of the adsorber bypass conduit and the hydrocarbon adsorber, the annular chamber being in communication with the exhaust gas inlet through the spacing between the nozzle outlet and the inlet of the adsorber bypass conduit, the annular chamber operating at a first pressure less than a second pressure within the housing at an outlet of the adsorber bypass conduit when the bypass valve is in the open position, an exhaust gas provided to the engine exhaust gas treatment device flowing in a first direction from the exhaust gas inlet to the exhaust gas outlet through the adsorber bypass conduit and flowing in a second direction from the exhaust gas outlet to the exhaust gas inlet through the hydrocarbon adsorber when the bypass valve is in the open position, the exhaust gas flowing through the hydrocarbon adsorber in the first direction when the bypass valve is in the closed position

20. The engine exhaust gas treatment device of claim 15, further comprising a catalyst member located within the housing between the hydrocarbon adsorber and the exhaust gas outlet.