Paccar Inc.

Maarten Meijer

Charles Wayne Reinhardt Swart

Cynthia Chaffin Webb

Varun Ramesh

John Lahti

Michael D Gerty

Uday Vadlamani

Constantin Emil Nedelcu

Trevor Joseph Ott

Kimberly Denise McKinnon

Nick Hertlein

Stephen Anthony Ciatti

Phillip William Stephenson

Brandon Rouse

Steve Ciatti

Michael Douglas Gerty

Kimberly Denise Mckinnon

A heavy-duty truck has a diesel engine, an exhaust after-treatment system, and an engine control unit. The exhaust after-treatment system includes a close-coupled selective catalytic reduction system and an underbody selective catalytic reduction system, a first NOsensor upstream of the close-coupled selective catalytic reduction system, a second NOsensor between the two selective catalytic reduction systems, and a third NOsensor downstream of the underbody selective catalytic reduction system. The engine control unit may perform methods allowing intrusive diagnostics to be performed on exhaust gas NOsensors using the selective catalytic reduction systems during normal operation of the heavy-duty truck.

NOsensor diagnostics in heavy-duty motor vehicle engines

A heavy duty truck includes a diesel engine that generates an exhaust gas flow and an exhaust after-treatment system for treatment of the exhaust gas flow. The exhaust after-treatment system includes at least one heater and at least one selective catalytic reduction system downstream of the heater. The heater is operated to inject supplemental heat energy into the exhaust gas flow at a rate based on a difference between a target rate of heat energy in the exhaust gas flow at an inlet to the selective catalytic reduction system and a rate of heat energy supplied to the exhaust gas flow from the diesel engine.

Heater control in heavy-duty motor vehicle engines

A method includes detecting a diesel engine runaway event in a diesel engine and, in response to detecting the diesel engine runaway event, deactivating all cylinders in the diesel engine such that no combustion occurs in any cylinders of the diesel engine and no cylinders of the diesel engine produce power, wherein deactivating the cylinders of the diesel engine includes mechanically decoupling a camshaft of the diesel engine from inlet valves of the cylinders of the diesel engine, and wherein deactivating cylinders of the diesel engine prevents flow of air from an intake manifold into combustion chambers of the cylinders.

Use of cylinder deactivation to prevent diesel engine runaway

Providing additional mass air flow to an engine of a vehicle to expand an operating range of cylinder deactivation (CDA) is provided. Aspects of the present disclosure describe a method and system to provide additional mass air flow to an engine using an auxiliary air source coupled to a turbocharger. When a low air-to-fuel ratio state is determined in association with operating the vehicle in CDA mode, the auxiliary air source is activated to assist the turbocharger with increase the supply of supercharged intake air to the engine. Accordingly, the operating range of CDA is expanded.

Cylinder deactivation expanded operational range with additional air source integrated with turbocharger

The present disclosure describes methods for evaluating NOx conversion efficiency of a close coupled SCR unit of an EAS including the close coupled SCR unit and a downstream SCR unit. The determined NOx conversion efficiency of the close coupled SCR unit is used to diagnose the close coupled SCR unit and or EAS and to control operation parameters of the EAS and/or internal combustion engine operably connected to the EAS.

Methods for diagnostics and operation of an emissions aftertreatment system

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

Methods for evaluating diesel exhaust fluid quality

A modular exhaust subsystem for purifying an exhaust gas feedstream of a compression-ignition internal combustion engine upstream of a base exhaust aftertreatment system includes a selective catalytic reduction (SCR) catalyst, and a first exhaust gas sensor and a first temperature sensor that are arranged to monitor the SCR catalyst. A reductant delivery system is arranged to inject a reductant upstream of the SCR catalyst. A controller is in communication with an engine-out exhaust gas sensor, a second exhaust gas sensor and a second temperature sensor that are arranged to monitor the base exhaust aftertreatment system. The controller controls the reductant delivery system to inject the reductant into the exhaust gas feedstream upstream of the SCR catalyst based upon inputs from the first and second exhaust gas sensors, the engine-out exhaust gas sensor, and the first and second temperature sensors.

Modular exhaust aftertreatment subsystem

Methods of improving SCR performance in heavy duty vehicles may use multiple interdependent control techniques to increase engine exhaust temperatures in a fuel efficient manner. One method combines cylinder deactivation and mechanical loading of an engine by an electrical generator used to input energy into an exhaust stream to manipulate the exhaust temperature through the combined effect of modified air-to-fuel ratio and supplemental energy input. In particular, cylinder deactivation may be used to modify the engine air flowrate and the electric generator may be used to apply mechanical load on the engine to manipulate the engine fuel flow rate to control the engine air-to-fuel ratio and thereby increase exhaust temperatures. The exhaust temperatures may be further increased by using the electrical generator to add the energy generated as input energy to the exhaust stream.

Control of exhaust energy in internal combustion engines

The present disclosure describes methods for evaluating ammonia storage capacity of a close-coupled SCR unit while remaining compliant with prescribed emissions limits, methods of controlling an emission aftertreatment system including multiple SCR units and emission management systems for a vehicle including an internal combustion engine and an emission aftertreatment system that includes two or more SCR units.

Ammonia storage capacity of SCR catalyst unit

The present disclosure describes methods for operating an EAS including a close coupled SCR unit, a downstream SCR unit, a diesel oxidation catalyst unit (DOC) and a diesel particulate filter (DPF). The methods utilize the close coupled SCR unit to manage NOx emissions from the EAS during regeneration of a diesel particulate filter (DPF).

Methods for operation of an emissions aftertreatment system for NOx control during regeneration of diesel particulate filter

A heavy duty truck includes a diesel engine, an exhaust after-treatment system, and an engine control unit. The exhaust after-treatment system may include one or more selective catalytic reduction systems, each with a respective heater, and each heater with a respective pair of temperature sensors, one upstream and the other downstream of the heater. Such systems may be used to perform diagnostic methods including populating a lookup table having heat energy supplied to an exhaust gas stream by the diesel engine as a first independent variable, heat energy supplied to the exhaust gas stream by a heater as a second independent variable, and a resulting temperature as an output. Such a lookup table can be used to maintain a temperature of the exhaust gas flow at a constant target temperature.

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Anacortes, WA, United States of America

Maarten Meijer