System and method for exhaust gas aftertreatment of internal combustion engine

Abstract

The invention relates to an exhaust gas aftertreatment system for an internal combustion engine (10), in particular for an internal combustion engine (10) which is charged by means of a turbocharger (30) and spark-ignited by means of spark plugs (16). A particulate filter (24) and an electrically heatable three-way catalytic converter (26) downstream of the particulate filter (24) are arranged ina position close to the engine in an exhaust gas system (20) connected to an outlet (12) of the internal combustion engine (10). A further three-way catalytic converter (28) is arranged in the underbody position of the motor vehicle downstream of the electrically heatable catalytic converter (26). According to the invention, the electrically heatable three-way catalytic converter (26) is heated electrically after engine start, and the particulate filter (24), the electrically heatable three-way catalytic converter (26) and the further three-way catalytic converter are additionally heated by the exhaust gas flow from the internal combustion engine (10). The electric heating of the electrically heatable three-way catalytic converter (26) is switched off when the electrically heatable three-way catalytic converter (26) has reached its light-off temperature.

Description

technical field [0001] The invention relates to an exhaust gas aftertreatment system for an internal combustion engine and a method for exhaust gas aftertreatment of an internal combustion engine according to the preambles of the independent patent claims. Background technique [0002] The continuous increase in exhaust gas regulations places high demands on vehicle manufacturers, which are met by appropriate measures for reducing untreated engine emissions and by appropriate exhaust gas aftertreatment. With the introduction of regulation level EU6, limit values ​​for particle counts are prescribed for Otto motors, which in many cases necessitate the use of Otto particle filters. Such soot particles are formed in particular after a cold start of the internal combustion engine due to incomplete combustion combined with an overstoichiometric combustion air ratio and cold cylinder walls during the cold start. The cold start phase is thus decisive for compliance with the legall...

AI Technical Summary

Problems solved by technology

A further problem in the case of three-way catalytic converters with coatings acting as three-way catalysis, so-called four-way catalytic converters, lies in the fact that the coatings can have strong aging phenomena, which can be detrimental to the gaseous In terms of material conversion, an additional three-way catalytic converter may be required in a position close to the engine

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