Gm Global Technolgoy Operations, Inc.

Other

Yong Miao

Christopher L Whitt

Kevin Andrew Gady

Min Sun

Michael A Smith

Charles Solbrig

Shouxian Ren

Se Hyuck Oh

Joshua Clifford Bedford

Julian C Tan

Stefano Pellegrino

Naser I Hineiti

Kurt Alfred Wellenkotter

Manuel Angel Gonzalez Delgado

Steven D Felix

Steven M Yocum

Paolo Di Martino

Exhaust gas systems include an oxidation catalyst (OC) capable of receiving exhaust gas and oxidizing one or more of combustible hydrocarbons (HC) and one or more nitrogen oxide (NOx) species, a selective catalytic reduction device (SCR) disposed downstream from and in fluid communication with the OC via a conduit, and an electrically heated catalyst (EHC) disposed at least partially within the conduit downstream from the OC and upstream from the SCR. The EHC comprises a heating element having an outer surface including one or more second oxidation catalyst materials capable of oxidizing CO, HC, and one or more NOx species. The OC includes one or more storage materials individually or collectively capable of storing NOx and/or HC species. Exhaust gas can be supplied by an internal combustion engine which can optionally power a vehicle.

Exhaust gas treatment systems utilizing a single electrically heated catalyst

A engine exhaust system includes a diesel oxidation catalyst (DOC) configured to receive the engine exhaust gases, a first electric heater coupled to the DOC, and a selective catalytic reduction (SCR) device in fluid communication with the DOC. The engine exhaust system further includes a second electric heater coupled to the DOC, a power switch controller in electronic communication with the first electric heater and the second electric heater, and a single power source electrically coupled to the power switch controller, the first electric heater, and the second electric heater. The power switch controller includes a switch to control a power distribution between the first electric heater and the second electric heater as a function of time.

Method to power multiple electric heaters with a single power source

A method for determining the hydrocarbon (HC) oxidation performance of an oxidation catalyst device (OC) includes communicating gas to the OC inlet over a time frame, measuring the NOx content of the OC outlet gas using a NOx sensor over the time frame, wherein the temperature of the OC increases over the time frame, and correlating an increased NOx measurement over the time frame to an increased OC HC oxidation performance. The NOx sensor can be operated in a low temperature mode during the time frame. The method can further include determining the temperature of the OC over the time frame and correlating the HC oxidation performance to the OC temperature, and/or correlating a maximum NOx concentration measured during the time frame to the OC temperature measured at the same time. HC slip through the OC can be identified when the measured NOx content of the OC outlet gas decreases.

Methods for determining oxidation performance of oxidation catalyst devices

A method and system for non-uniform catalyst heating for reducing exhaust gas emissions when the catalyst is below a predetermined light off temperature is provided. The method includes providing a catalyst formed of a plurality of electrically conductive subsections and at least one catalyst heating device that is operable to heat at least one of the plurality of electrically conductive subsections of the catalyst to form at least one predetermined non-uniform heating pattern. A heater control module is provided for controlling the operation of the at least one catalyst heating device. If the engine is in a cold start condition, then the heater control module causes the at least one catalyst heating device to heat at least one of the electrically conductive subsections of the catalyst to obtain a first predetermined non-uniform heating pattern.

Method and system for non-uniform catalyst heating for internal combustion engine

Methods for monitoring the performance of an oxidizing catalyst device are provided. Methods can include treating an exhaust gas stream with the oxidizing catalyst device, determining a reference liberated oxygen (LO) species measurement of the exhaust gas stream, measuring a downstream LO species measurement of the exhaust gas stream using a NOsensor in a catalyst inactive mode, and determining a LO species differential. The downstream NOsensor can comprise an amperometric sensor and include a NOselective reduction catalyst. Methods for using an amperometric NOsensor utilizing an NOselective reduction catalyst are also provided, and include operating the NOx sensor in a catalyst active mode to generate a first LO species measurement, operating the NOsensor in a catalyst inactive mode to generate a second LO species measurement, and comparing the first LO species measurement to the second LO species measurement to determine a LO species differential.

Methods of using gas sensors

A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NOwhen the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NOwhen the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NO. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NOemissions from a diesel engine, the NOemissions including NOemitted during a predetermined cold-start time period.

Dual-layer catalyst

A system is provided and includes a fuel module that, based on a crankshaft angle of an engine, generates a value indicative of an amount of fuel burned in a cylinder or a change in the amount of fuel burned. A heat release module, based on the value, determines an amount of heat released during a combustion event of the cylinder. A pressure module, based on the amount of heat released, estimates a pressure in the cylinder. A temperature module, based on the pressure, estimates a temperature in the cylinder. A concentration module, based on the pressure or the temperature, estimates nitrogen oxide concentration levels in the cylinder. An output module, based on the nitrogen oxide concentration levels, estimates an amount of nitrogen oxides. A control module, based on the amount of nitrogen oxides out of the cylinder, controls operation of the engine or an exhaust system.

Method and apparatus for estimating nitrogen oxides out of an engine

An exhaust gas system for an engine producing an exhaust gas includes an exhaust gas tube configured to receive the exhaust gas. A particulate filter is in fluid communication with the exhaust gas tube and configured to undergo thermal regeneration when the exhaust gas in the particulate filter is heated above a regeneration temperature. A generator unit is positioned downstream of the particulate filter and includes a first catalyst. A tank is configured to store a precursor material. The generator unit is configured to employ the precursor material and the heat generated for the thermal regeneration of the particulate filter to generate an ammonia gas from the precursor material. The system includes a controller having a processor and tangible, non-transitory memory on which is recorded instructions for executing a method of controlling generation of ammonia gas in the generator unit and injection of ammonia gas in the exhaust gas tube.

Generation and delivery of ammonia gas in an exhaust gas system

In an exemplary embodiment, an internal combustion engine includes an oxidation catalyst configured to receive an exhaust gas flow from the internal combustion engine, a urea injector positioned downstream of the oxidation catalyst to inject a urea flow into the exhaust gas flow and a mixer positioned downstream of the urea injector to mix the exhaust gas flow and the urea flow to form a mixed exhaust gas and urea flow. The engine also includes a particulate filter and catalytic reduction assembly positioned downstream of the mixer to receive the mixed exhaust and urea flow from the mixer to form a treated exhaust gas flow and an exhaust gas recirculation system coupled to the particulate filter to receive a portion of the treated exhaust gas flow and recirculate the portion of the exhaust gas flow to be mixed with a fresh air flow for the internal combustion engine.

Exhaust aftertreatment and exhaust gas recirculation systems

A mixer for an exhaust aftertreatment system is disclosed. The mixer includes a body portion that is configured to be disposed in an exhaust conduit of an exhaust aftertreatment system upstream of an exhaust aftertreatment device. The mixer also includes an airfoil portion that is disposed on the body portion and reversibly movable between a deployed position and a retracted position, wherein in the deployed position the airfoil portion provides a deployed resistance to an exhaust gas flow and in the retracted position provides a retracted resistance thereto, and the deployed resistance is greater than the retracted resistance, the body portion and airfoil portion comprising a mixer. The mixer further includes a bimetallic couple that is operatively joined to the mixer and configured to reversibly move the airfoil portion from the retracted position to the deployed position.

Reconfigurable bi-metallic mixer for an exhaust aftertreatment system and method of using the same

An exhaust gas treatment system for an internal combustion engine is provided, having an exhaust gas conduit, a reductant source, a temperature sensor, an intake mass air flow sensor, and a control module. The exhaust gas conduit is in fluid communication with, and is configured to receive an exhaust gas from the internal combustion engine. The exhaust gas contains oxides of nitrogen ('NO'). The reductant source is in fluid communication with the exhaust gas conduit and is configured for injecting an amount of reductant that is released into the exhaust gas conduit. The temperature sensor is situated in the exhaust stream for determining a temperature of the exhaust gas at the reductant source. The intake mass air flow sensor measures an air mass flow entering the internal combustion engine. The control module is in communication with the reductant source, the temperature sensor, and the intake mass air flow sensor.

System and method for determining a maximum dose rate of reductant

A dosing control system comprises a selective catalytic reduction (SCR) analysis module and a dosing management module. The SCR analysis module estimates an ammonia (NH3) slip rate downstream of an SCR catalyst, an NH3 conversion rate, an NH3 supply rate, and an NH3 oxidation rate. The SCR analysis module estimates an NH3 rate of change based on the NH3 slip, conversion, supply, and oxidation rates and estimates an NH3 storage change based on the NH3 rate of change. The SCR analysis module estimates NH3 stored by the SCR catalyst based on the NH3 storage change. The dosing management module controls dosing agent injection into an exhaust system upstream of the SCR catalyst based on the NH3 stored by the SCR catalyst.

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Ann Arbor, MI, United States of America

Yong Miao