Managing Reductant Slip in an Internal Combustion Engine
AssigneeFord Global Technologies, LLC
InventorEric Matthew Kurtz
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Abstract
A method for controlling operation of vehicle system including an internal combustion engine and a catalytic emission control device coupled in an exhaust of the engine, the method including delivering, which may include injecting into the exhaust, reductant to the emission control device responsive to vehicle operating conditions, and increasing emission control device inlet-NOx in response to reductant release from the emission control device.
Claims21
A method for controlling operation of vehicle system including an internal combustion engine and a catalytic emission control device coupled in an exhaust of the engine, the method comprising:
- delivering reductant to the emission control device responsive to vehicle operating conditions;
- and
- increasing emission control device inlet-NOx in response to a reductant release from the emission control device.
A method for controlling operation of vehicle system including a diesel internal combustion engine and an SCR emission control device coupled in an exhaust of the engine, the method comprising:
- injecting urea to the SCR emission control device responsive to vehicle operating conditions, where at least a portion of the injected urea is stored as a reductant in the SCR emission control device;
- when temperature of the SCR emission control device changes such that a reductant storage capacity of the SCR emission control device falls below or approaches a current level of reductant stored in the SCR emission control device, an engine operating parameter is adjusted in response to an amount by which the reductant storage capacity falls below or is anticipated to fall below the current level of reductant, the engine operating parameter adjusted to increase emission control device inlet-NOx to react with reductant otherwise exiting the emission control device;
- and
- further stopping injection of urea when temperature of the SCR emission control device changes such that the reductant storage capacity of the SCR emission control device falls below the current level of reductant stored in the SCR emission control device.
An internal combustion engine system comprising:
- a cylinder having an intake and an exhaust;
- an emission control system including a reductant delivery system coupled downstream of the cylinder and an SCR catalyst coupled downstream of the cylinder;
- and
- a control system configured to adjust injection of a reductant, via the reductant delivery system, into the emission control system responsive to one or more engine operating conditions, stop the reductant injection into the emission control system responsive to an increase in SCR temperature sufficient to decrease an SCR catalyst reductant storage capacity below a current amount of stored reductant, and increase NOx produced in combustion in response to an amount of reductant released due to the decrease in capacity below the current amount of stored reductant in SCR catalyst.
Dependencies are inferred from the claim text.