Detroit Diesel Corporation

Gm Global Technolgoy Operations, Inc.

Ravishankar Ramamurthy

Sameer Bhargava

Phillip F Rimnac

Laurentiu Vaduva

Shouxian Ren

Brian Andrew Lewallen

Admir Krejo

Sameer Bhargara

An exhaust aftertreatment system for a diesel engine includes a selective catalytic reduction (SCR) device and a diesel oxidation catalyst upstream of the SCR device. A method for warming-up the SCR device includes monitoring a plurality of combustion input parameters during an SCR warm-up strategy, monitoring a first temperature and a second temperature within the aftertreatment system, providing a feedback adjustment term as a function of a deviation in the first temperature from a desired temperature only when the monitored first and second temperatures are within a predetermined adjustment range, and initiating an adjusted SCR warm-up strategy based on the feedback adjustment term to converge the first temperature toward the desired temperature.

Closed loop temperature control in the SCR warm up mode to reduce emission variation

A NOestimation system includes an operating mode determination module that determines an operating mode of an engine, and an emission prediction module. The emission prediction module estimates NOemission based on the operating mode, a plurality of sensed parameters, and a map. The map correlates the plurality of sensed parameters to the NOemission based on the operating mode.

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A turbocharger protection system for an engine system that includes a particulate filter and a turbocharger comprises a delta pressure estimator that estimates a pressure difference in a particulate filter. A pressure factor estimator module estimates a pressure factor based on the difference and barometric pressure. A fuel limit estimator module protects the turbocharger by selectively limiting fuel injection to the engine based on the pressure factor.

Turbocharger protection systems and methods

A control system and method that compensates for changes in backpressure of an engine includes a pressure sensor that senses the backpressure. A boost compensation module that communicates with the pressure sensor, determines an averaged BC factor, and adjusts a variable geometry turbo based on the averaged BC factor.

Engine backpressure compensation system for stable emissions

A method for controlling exhaust gas particulate emissions from a compression ignition internal combustion engine having a variable geometry turbocharger (VGT) includes the steps of determining backpressure across the engine and air mass flow into the engine, closing vanes of the VGT to provide air mass flow increase when backpressure is increasing, and stopping the step of closing the vanes of the VGT when a decrease in rate of change of air mass flow is determined.

System and method for backpressure compensation for controlling exhaust gas particulate emissions

A control and method for an internal combustion engine that includes an exhaust gas recirculation system to predict an intake manifold critical temperature (dew point) at which condensation would occur upon entry into exhaust gas recirculation. The control calculates the intake manifold critical temperature (IMT_Critical) as a function of predetermined, sensed or assumed values by processing an equation whose variables are occupied by the values. The control commands adjustments of exhaust gas recirculation operation in response to the calculation, preferably after the actual intake manifold temperature exceeds the IMT_Critical for a predetermined time.

Influence of engine parameters on condensation protection strategies

A control for an internal combustion engine that includes an exhaust gas recirculation system predicts at least one of the intake manifold temperature in EGR mode or an intake manifold pressure in EGR mode, but preferably both, during Boost mode operation. The predictions are relied upon to calculate an intake manifold critical temperate in EGR, at which condensation would occur. The control then compares the predicted temperate value with the calculated intake manifold critical temperature, and if the predicted value exceeds the calculated temperature, the control commands re-entry into exhaust gas recirculation mode.

Re-entry strategy from boost mode to EGR mode

An exhaust gas recirculation system for a compression ignition engine is provided wherein the exhaust gas recirculation is shut off depending upon the sensed or calculated humidity in the intake manifold relative to the dew point of the exhaust/intake air mixture. The humidity of the exhaust/intake air mixture may be measured in the intake manifold, charge air mixer or the ambient humidity may be sensed. If humidity is measured in the air charge mixer or in the ambient air, other factors such as engine speed and load, intake manifold pressure, EGR flow and air/fuel ratio may be used to calculate the humidity in the intake manifold. When the temperature of the mixture in the intake manifold is less than the dew point of the mixture, the engine control strategy may be shut off the EGR to prevent condensation in the exhaust gas recirculation system or engine.

Method of controlling exhaust gas recirculation system based upon humidity

A system and method for controlling an internal combustion engine to reduce or eliminate formation of EGR condensate monitor current ambient and operating conditions to determine whether conditions are favorable for condensation of EGR gases, and control the engine accordingly to avoid condensation, preferably by increasing the intake manifold temperature. The intake manifold temperature may be increased by redirecting some or all of the EGR flow to avoid the EGR cooler. Alternatively, or in combination, some or all of the charge air may be redirected to bypass the charge air cooler and/or redirected from the outlet of the turbocharger compressor to the intake, effectively increasing the intake air temperature and resulting in a corresponding increase of the intake manifold temperature. Conditions favorable for condensation may be determined based on engine speed and load, ambient temperature, manifold pressure, scheduled or actual EGR flow rate and scheduled or actual air/fuel ratio.

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Westland, MI, United States of America

Ravishankar Ramamurthy