Paccar Inc.

Nathan Jon Kaemingk

Michael D Gerty

Paul J Troxler

Daniel William Sloan

Systems and methods are provided for controlling the amount and timing of nitrogen oxide reductant injected during a given injection cycle into an exhaust system of a vehicle as part of a selective catalytic reduction system. The amount of reductant injected is determined by at least one computational model that accounts for the growth of liquid and/or solid reductant film growth on the interior of the exhaust system. The model determines reductant injection characteristics (e.g., amount, timing, etc.) that reduce and/or eliminate reductant films on the interior of the exhaust system. Exemplary inputs into the model include exhaust temperature, exhaust flow, and the amount of reductant injected in a previous injection cycle.

Injector control for a selective catalytic reduction system

Systems and methods are provided for controlling the amount and timing of nitrogen oxides reductant injected during a given injection cycle into an exhaust system of a vehicle as part of a selective catalytic reduction system. The amount of reductant injected is determined by at least one computational model that accounts for the growth of liquid and/or solid reductant film growth on the interior of the exhaust system. The model determines reductant injection characteristics (e.g., amount, timing, etc.) that reduce and/or eliminate reductant films on the interior of the exhaust system. Exemplary inputs into the model include exhaust temperature, exhaust flow, and the amount of reductant injected in a previous injection cycle.

Various diffusion apparatuses are provided for facilitating the injection of a nitrogen-oxides reductant solution, such as urea, into exhaust gas as part of a selective catalytic reduction system. These diffusion apparatuses direct exhaust gas from an exhaust pipe, through a conduit, and into a diffusion chamber where urea is injected. The flow of exhaust gas through the conduit provides improved transport of injected reductant solution into the exhaust pipe, and adhesion of the reductant solution to the walls of the diffusion chamber is reduced.

Reductant delivery device

Systems and methods are provided for measuring the thickness of a film on an interior surface of an exhaust pipe system of a vehicle. The film is typically a layer of a nitrogen-oxides reductant, such as urea, deposited during operation of a selective catalytic reduction system for eliminating pollutants in an exhaust stream. The methods and systems are directed to optical measurements that directly probe the interior surfaces of the exhaust system to determine the thickness of a urea film built up during operation of the engine and the selective catalytic reduction system.

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Lynden, WA, United States of America

Nathan Jon Kaemingk