Method of controlling fuel in an exhaust treatment system implementing temporary engine control

Abstract

An exhaust treatment system associated with a power source is disclosed. The exhaust treatment system may have a filter located to remove particulate matter from a flow of exhaust, and a regeneration device located proximal the filter. The exhaust treatment system may also have a first fluid handling component located upstream of the power source to vary an amount of oxygen in the flow of exhaust, a second fluid handling component located downstream of the power source to vary the amount of exhaust air flow in the exhaust circuit, and a controller in communication with the regeneration device and the fluid handling component. The controller may determine a need for filter regeneration, and determine adjustments to the first and second fluid handling components required to provide sufficient oxygen and air mass flow in the exhaust for filter regeneration. The controller may further determine an effect the adjustments will have on operation of the power source, and determine corrections for the power source to account for the effects. The controller may substantially simultaneously implement the adjustments and the corrections.

Description

TECHNICAL FIELD [0001]The present disclosure relates generally to an exhaust treatment system and, more particularly, to a method of controlling fuel in an exhaust treatment system that implements temporary engine control.BACKGROUND [0002]Engines, including diesel engines, gasoline engines, natural gas engines, and other engines known in the art, exhaust a complex mixture of air pollutants. The air pollutants may be composed of gaseous and solid material, which include nitrous oxides (NOx) and particulate matter. Due to increased attention on the environment, exhaust emission standards have become more stringent and the amount of NOx and particulate matter emitted from an engine may be regulated depending on the type of engine, size of engine, and / or class of engine.[0003]One method that has been implemented by engine manufacturers to comply with the regulation of NOx exhausted to the environment has been to recirculate exhaust gas from an engine back into the engine for subsequent ...

AI Technical Summary

Benefits of technology

[0009]In one aspect, the present disclosure is directed to an exhaust treatment system associated with a power source. The exhaust treatment system may include a filter located downstream of the power source to remove particulate matter from a flow of exhaust produced by the power source. The exhaust treatment system may also include a regeneration device located proximal the filter to raise a temperature of the removed particulate matter above an ignition threshold. The exhaust treatment system may also include a first fluid handling component located upstream of the power source to vary an amount of oxygen in the flow of exhaust, and a second fluid handling component located downstream of the power source and upstream of the regeneration device to vary the flow of exhaust bypassing the regeneration device. The exhaust treatment system may also include a controller in communication with the power source, filter, regeneration device, first fluid handling component, and second fluid handling component. The controller may be configured to determine a need for filter regeneration. The controller may also be configured to determine a first adjustment to the first fluid handling component to provide sufficient oxygen in the exhaust flow for filter regeneration. Further, the controller may also be configured to determine a second adjustment to the second fluid handling component to provide sufficient mass flow in the exhaust bypassing the regeneration device. The controller may also facilitate the regeneration of the filter.

[0011]In yet another aspect, the present disclosure is directed to an engine system having an engine configured to combust a fuel and air mixture to generate power and a flow of exhaust. The engine system may also have a charged air induction circuit configured to introduce compressed air into the engine. The system may also have an exhaust circuit configured to direct the flow of exhaust from the engine to the atmosphere. Further, the system may have a filter located downstream of the engine to remove particulate matter from the flow of exhaust. The system may also include a regeneration device located proximal the filter to raise a temperature of the removed particulate matter above an ignition threshold. A first valve may be located upstream of the engine to vary an amount of oxygen in the flow of exhaust. A second valve may also be located downstream of the engine and upstream of the regeneration device to vary the flow of exhaust bypassing the regeneration device. The system may also include a controller in communication with the engine, filter, regeneration device, first valve and second valve. The controller may be configured to determine a need for particulate filter regeneration. The controller may also determine a first adjustment to the first valve regulating oxygen in the exhaust flow for filter regeneration. The controller may also determine a second adjustment to the second valve regulating exhaust flow bypassing the regeneration device. Further, the controller may also facilitate the regeneration of the filter.

Problems solved by technology

Although efficient at removing particulate matter from an exhaust flow, the use of the particulate filter for extended periods of time may cause the particulate matter to build up in the filtration medium, thereby reducing the functionality of the filter and subsequent engine performance.

Although the recirculation of exhaust gas and the use of a particulate filter may minimize the discharge of NOx and particulate matter to the atmosphere, both methods may affect or be affected by the amount of oxygen entering and leaving the engine.

Thus, when EGR is operational, regeneration of the particulate filter may be only minimally effective, as the amount of oxygen available for regeneration is reduced by the use of EGR.

Although the engine of the '218 publication may utilize and benefit from both an EGR system and a particulate filter, operation of the associated engine may be non-compliant and / or sub-optimal during regeneration.

That is, because EGR is utilized to reduce NOx emissions, by turning EGR off (i.e., by closing the EGR valve) during particulate regeneration, the engine may discharge excessive amounts of NOx during that time period.

In addition, because relative amounts of air and fuel entering and being combusted by the engine change when the EGR valve closes, regeneration of the particulate filter could negatively and / or unexpectedly affect other aspects of engine performance (i.e., power output, fuel consumption, etc.) during the regeneration period.

Additionally, during regeneration, large quantities of fuel are consumed as the fuel-fired burner heats all of the exhaust gases coming from the power source.

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