DE102013207228A1 - Oxidation Catalyst Monitor - Google Patents

Abstract

A control method for monitoring an oxidation catalyst of an exhaust system is provided. The control method includes determining a control factor based on an aging factor and an efficiency curve; controlling injection of hydrocarbons into an exhaust stream based on the control factor; and monitoring the oxidation catalyst based on the injection of hydrocarbons.

Description

FIELD OF THE INVENTION

The present invention relates to methods and systems for monitoring an oxidation catalyst of an exhaust system.

BACKGROUND

An oxidation catalyst device is provided in an exhaust system to treat unburned gaseous and non-volatile hydrocarbons (HC) and carbon monoxide (CO). The oxidation catalyst oxidizes the HC and CO under high temperature conditions to form carbon dioxide (CO ₂ ) and water (H ₂ O). As the oxidation catalyst ages, its ability to oxidize HC and CO is compromised. Accordingly, it is desirable to provide methods and systems that monitor the operation of the oxidation catalyst.

SUMMARY OF THE INVENTION

In an exemplary embodiment, a control method for monitoring an oxidation catalyst is provided. The control method comprises: determining an open loop factor based on an aging factor and an efficiency curve; Controlling an injection of hydrocarbons in an exhaust stream based on the control factor; and monitoring the oxidation catalyst based on the injection of hydrocarbons.

In another exemplary embodiment, a control system for monitoring an oxidation catalyst of an exhaust system is provided. The control system includes a first module that determines a control factor based on an aging factor and an efficiency curve. A second module controls injection of hydrocarbons into an exhaust stream based on the control factor. A third module monitors the oxidation catalyst based on the injection of hydrocarbons.

In yet another exemplary embodiment, an exhaust system of an engine is provided. The exhaust system includes an oxidation catalyst and a control module. The control module determines a control factor based on an aging factor and an efficiency curve, injects hydrocarbons into an exhaust gas flow based on the control factor, and monitors the oxidation catalyst based on the injection of hydrocarbons.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

1 FIG. 4 is a functional block diagram of a vehicle having an engine and an exhaust system according to exemplary embodiments; FIG.

2 FIG. 10 is a data flow diagram of an exhaust system control system according to exemplary embodiments; FIG. and

3 FIG. 10 is a flowchart illustrating a control method for an exhaust system according to example embodiments. FIG.

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 throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. The term module 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 combinational logic circuit and / or other suitable components that provide the described functionality.

Now referring to 1 is an exemplary embodiment of the invention to a vehicle 10 directed, which is an exhaust treatment system 12 for the reduction of regulated exhaust components of an internal combustion engine 14 having. As noted, the exhaust treatment system described herein may 12 be implemented in different engine systems. For example, such engine systems may include, but are not limited to, diesel engine systems, gasoline engine systems, and homogeneous compression ignition engine systems.

As in 1 is shown, the exhaust treatment system 12 generally one or more exhaust pipes 16 and one or more Exhaust treatment devices on. The exhaust treatment devices may include an oxidation catalyst device (OC). 18 exhibit. In the example of 1 the exhaust treatment devices further comprise a selective catalytic reduction (SCR) device 20 and a particle filter (PF) 22 on. As noted, the exhaust treatment system 12 various combinations of the OC 18 and other exhaust treatment devices, and is not limited to the present example.

In 1 transports the exhaust pipe 16 , which may include multiple segments, exhaust 24 from the engine 14 to the exhaust treatment devices of the exhaust treatment system 12 , The OC 18 For example, it may comprise a flow through metal or ceramic monolith substrate. The substrate may be in a shell or canister having an inlet and an outlet in fluid communication with the exhaust conduit 16 be packed. The substrate may have an oxidation catalyst compound disposed thereon. The oxidation catalyst compound may be applied as a washcoat and may include platinum group metals such as platinum (Pt), palladium (Pd), rhodium (Rh) or other suitable oxidizing catalysts or combinations thereof. The OC 18 treats unburned gaseous and non-volatile hydrocarbons and CO that are oxidized to form CO ₂ and H ₂ O.

A control module 32 controls the engine 14 and one or more components of the exhaust treatment system 12 based on collected and / or modeled data. For example, detect one or more sensors 34 a temperature of the exhaust gas 24 at various locations in the exhaust system 12 and generate a sensor signal based thereon. The control module 32 receives the signal and monitors the operation of the OC 18 based on the signal and OC monitoring systems and methods of the present disclosure.

In various embodiments, the control module provides 32 A level of HC (eg, excess fuel) present in the exhaust gas is controlled by controlling injection of fuel into the exhaust gas (eg, into the cylinder or exhaust pipe). The control module 32 sets the level based on an aging factor and an efficiency factor. The control module 32 monitors the operation of the OC 18 based on the set HC injection and sets a diagnostic code based on the monitoring. The control module 32 may also report the diagnostic code according to various reporting methods, including, but not limited to, the use of in-vehicle communication and / or off-vehicle reporting messages.

Now referring to 2 and with continued reference to 1 1 illustrates a data flow diagram of various embodiments of a control system of an exhaust system incorporated in the control module 32 can be embedded. Various embodiments of the exhaust system control systems according to the present disclosure may include any number of submodules included in the control module 32 are embedded. As noted, the in 2 Submodules shown combined and / or further partitioned to the operation of the OC 18 ( 1 ) in a similar way. Inputs to the system can be from the exhaust system 12 detected, received from other control modules (not shown) and / or other submodules (not shown) in the control module 32 determined / modeled. In various embodiments, the control module 32 a factor determination module 40 , a KW control module 42 and an assessment module 44 on.

The factor determination module 40 receives as input an aging factor 46 and an efficiency curve 48 , The aging factor 46 is a value that causes aging of the OC 18 ( 1 ) indicates. For example, the aging factor 46 on driven route, operating hours of the engine 14 ( 1 ) or any other time-based value. The efficiency curve 48 is a record of predicted efficiencies of the OC 18 ( 1 ) indicates different ages. The efficiency curve 48 For example, it may be determined from exhaust system parameters or may be based on physical characteristics of the OC 18 ( 1 ) be predefined.

Based on the aging factor 46 and the efficiency curve 48 determines the factor determination module 40 a control factor 50 , In various embodiments, the control factor 50 for example, between one and two and can be retrieved from a look-up table, the on the efficiency curve 48 and the aging factor 46 is ordered.

The KW control module 42 receives as input the control factor 50 , Based on the control factor 50 generates the KW control module 42 control signals 52 for the engine 14 ( 1 ) and / or the exhaust system 12 ( 1 ) to a level of hydrocarbons in the exhaust gas 24 ( 1 ) to control. For example, the control factor 50 with a certain KW amount 54 multiplied by a set KW amount 56 to determine. The control signals 54 be for the engine 14 ( 1 ) and / or for the exhaust system 12 ( 1 ) based on the set KW amount 56 generated.

The report module 54 receives as input sensor signals 58 that is a temperature of the exhaust gas 24 ( 1 ) downstream of the OC 18 ( 1 ) specify. The report module 44 evaluates the sensor signals 58 based on the set KW amount 56 to determine if the actual temperature has reached an expected temperature. If the actual temperature is equal to or within a range of the expected temperature, then the OC 18 ( 1 ) is diagnosed as operable, and an error status or diagnostic code is set to indicate that there is no error. However, if the actual temperature is outside the range of the expected temperature, then the OC 18 ( 1 ) is diagnosed as faulty, and an error status or diagnostic code is set to indicate an error.

The report module 44 can then read the error status or diagnostic code via a message 60 to report. In various embodiments, the reporting engine generates 44 the message 60 on a serial data bus (not shown) of the vehicle 10 ( 1 ), the message being sent to a remote location using a telematics system (not shown) of the vehicle 10 ( 1 ) or retrieved by a technician tool (not shown) connected to the vehicle 10 ( 1 ) connected is.

Now referring to 3 and with continued reference to the 1 and 2 FIG. 12 is a flowchart showing an exhaust system control process performed by the control module 32 from 1 according to the present disclosure. As noted in view of the disclosure, the order of operation in the method is not limited to the sequential execution as in FIG 3 but may be implemented in one or more varying orders, as applicable, and in accordance with the present invention.

In various embodiments, the method may be scheduled to run based on predetermined events and / or during operation of the engine 14 runs continuously.

In one example, the method can be used with 100 kick off. The aging factor 46 is at 100 certainly. The efficiency curve 48 is at 110 certainly. The control factor 50 is at 120 from the aging factor 46 and the efficiency curve 48 certainly. The set KW amount 56 is at 130 based on the control factor 46 certainly. The control signals 52 become at 140 generated to the set KW amount 56 to reach.

The sensor signals 58 become at 150 rated. When the sensor signals 58 at 150 indicate that the exhaust gas temperature is in a range, then at 160 the error status is set to indicate that no error exists, and at 170 will the message 60 generated, which has the error status. If, however, at 150 the sensor signals 58 indicate that the exhaust gas temperature is outside a range, then at 180 the error status is set to indicate an error, and at 170 will the message 60 generated, which has the error status. The method may be included 190 end up.

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, but that the invention encompass all embodiments falling within the scope of the application.

Claims (10)

A control method for monitoring an oxidation catalyst of an exhaust system, comprising: Determining a control factor based on an aging factor and an efficiency curve; Controlling an injection of hydrocarbons into an exhaust stream based on the control factor; and Monitoring the oxidation catalyst based on the injection of hydrocarbons. A control system for monitoring an oxidation catalyst of an exhaust system, comprising: a first module that determines a control factor based on an aging factor and an efficiency curve; a second module that controls injection of hydrocarbons into an exhaust stream based on the control factor; and a third module that monitors the oxidation catalyst based on the injection of hydrocarbons. The control system of claim 2, wherein the aging factor is determined based on a traveled distance and / or an operating time. A control system according to claim 2, wherein the efficiency curve is based on physical Characteristics of the oxidation catalyst is predefined. The control system of claim 2, wherein the efficiency curve is determined based on detected parameters of the exhaust system. The control system of claim 2, wherein the third module monitors the oxidation catalyst based on a temperature of the exhaust gas leaving the oxidation catalyst. The control system of claim 6, wherein the third module generates a message based on the monitoring. Exhaust system of an engine comprising: an oxidation catalyst; and a control module that determines a control factor based on an aging factor and an efficiency curve that injects hydrocarbons into an exhaust gas flow based on the control factor and that monitors the oxidation catalyst based on the injection of hydrocarbons. The exhaust system of claim 8, wherein the aging factor is determined based on a traveled distance and / or operation. The exhaust system of claim 8, wherein the control module monitors the oxidation catalyst based on a temperature of the exhaust gas leaving the oxidation catalyst.

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