Exhaust gas detection and treatment, and related systems

Abstract

A method for calculating the relative ratios of NH3 and NOx in exhaust gases to detect NH3 slip using NOx sensors includes measuring a first NOx level at an upstream NOx sensor, administering a first predetermined dose of urea to the exhaust gases, measuring a second NOx level at a downstream NOx sensor, administering a second predetermined dose of urea to the exhaust gases, measuring a third NOx level at the downstream NOx sensor, calculating a difference between the second NOx level and the third NOx level, and comparing the difference between the second NOx level and the third NOx level to a lookup table to determine a ratio of a concentration of NH3 to a concentration of NOx in the exhaust gases. Related systems and methods are also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of the filing date of U. K. Patent Application 1818633.8, “NOX SLIP DETECTION,” filed Nov. 15, 2018; and U.K. Patent Application 1820820.9, “NH3 SLIP DETECTION IN EXHAUST SYSTEMS, filed Dec. 19, 2018; the entire disclosures of each of which are incorporated herein by reference.FIELD[0002]The present disclosure relates to a method of determining the ratio of NH3 to NOx in exhaust gases leaving an exhaust system of an internal combustion engine.BACKGROUND[0003]There is a rising demand for cleaner and more efficient internal combustion engines, especially diesel engines. Diesel engines emit particulate matter as well as nitrogen oxides (NOx) from their exhaust systems.[0004]The exhaust systems of working vehicles such as tractors often include one or more systems to clean the exhaust gases, such as a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF) for particulate matter treatment, a sele...

AI Technical Summary

Benefits of technology

The patent describes a method to reduce NOx emissions from an agricultural vehicle's exhaust system. The method involves using a larger dose of NH3 and multiple catalysts to further reduce NOx levels. A temperature sensor is also included to improve reaction kinetics and equilibrium. Additionally, a diesel particulate filter is included to reduce particulate matter that passes to the atmosphere from the engine. The method is cost-effective and efficient, resulting in reduced pollutant output from the exhaust system.

Problems solved by technology

Because the normal dosage levels are much smaller, this means less accurate sensors may be used, which are generally cheaper than those that are more accurate.

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