System for injecting reactants in an exhaust line

Abstract

A system to be fitted on an automotive vehicle for injecting reactants in an exhaust line of an engine of the vehicle includes a source of a liquid precursor of ammonia, a source of gaseous ammonia, an injection assembly designed to be fitted on the exhaust line and to inject liquid precursor and / or gaseous ammonia inside the exhaust line, the injection assembly including a single injector body to be fitted on the exhaust line, the injector body having a first inlet for the liquid precursor, a second inlet for the gaseous ammonia, and at least one outlet for injection inside the exhaust line.

Description

BACKGROUND AND SUMMARY[0001]The present invention relates to a system for injecting reactant(s) in an exhaust line of an engine. It may be used in the context of treating nitrogen oxides contained in exhaust gases flowing in an exhaust line of the engine, especially but not exclusively in a vehicle.[0002]Exhaust gases formed due to the combustion of fuel in an internal combustion engine may contain a proportion of undesirable components, in particular nitrogen oxides (NOx).[0003]Various exhaust after-treatment systems are known for removing or reducing the amount of undesirable components. Some of these systems require that at least one reactant fluid is injected in the exhaust line to react with the exhaust gases, either directly, or indirectly after having undergone one or several chemical transportation, and / or with the help of catalysts.[0004]One known example of such an exhaust after-treatment system is the so-called selective catalytic reduction (SCR) system which has been imp...

AI Technical Summary

Benefits of technology

The invention is a compact and cost-effective injector system for delivering gas ammonia and liquid precursor to a reaction chamber. The system includes a single injector body, which simplifies system integration and reduces overall cost. The injector can be designed to have a single inlet for both the liquid precursor and gas ammonia, which simplifies operation and reduces the need for a perfectly nebulized spray. The system also includes a flow control system that allows for controlling the flow of both the liquid precursor and gas ammonia, making it flexible for different operating conditions. In summary, the invention simplifies the injector and improves system efficiency.

Problems solved by technology

One problem with this type of exhaust gases treatment system is that, in some operating conditions of the engine, especially when the temperature of the exhaust gases is relatively low, for example around 20.0° C., urea, and / or it's the intermediate product in its transformation into ammonia, can crystallize before it has transformed into ammonia.

One consequence is that the cross section of the exhaust pipe may be progressively reduced, which may decrease the engine efficiency and which can seriously impair the engine operation in the long term.

Also, this can lead to an improper treatment of the exhaust gases, leaving too much NOx.

This solution therefore proves inconvenient insofar as it requires frequent replacement of the containers and the corresponding infrastructure to handle and replace these containers.

Such a system is expensive and is complicated to install, especially on a vehicle where available space is often scarce.

Said protection package can be fairly complicated and expensive due to the constraints resulting from the hot environment.

Images