INTERNAL COMBUSTION ENGINE WITH SELECTIVE CATALYTIC CONVERTER FOR THE REDUCTION OF NITROGEN OXIDES AND METHOD FOR OPERATING AN INTERNAL COMBUSTION ENGINE OF SAID TYPE

摘要

An internal combustion engine comprising a turbocharger wherein a bypass line in an exhaust gas discharge system delivers an aqueous urea reductant to an at least one SCR catalyst and a method to maintain the reductant at a desired temperature to maximize its conversion to ammonia and optimize the reduction of NOx in the SCR.

主权项

1. An internal combustion engine comprising:
an intake system for the supply of charge air; an exhaust-gas discharge system for the discharge of the exhaust gases wherein the exhaust-gas discharge system further comprises; at least one selective catalytic converter arranged in the exhaust-gas discharge system and which serves for the reduction of nitrogen oxides; an oxidation catalytic converter being arranged, as a further exhaust-gas aftertreatment system, in the exhaust-gas discharge system upstream of the at least one selective catalytic converter wherein; a bypass line branches off from the exhaust-gas discharge system upstream of the oxidation catalytic converter and issues into the exhaust-gas discharge system again between the oxidation catalytic converter and the at least one selective catalytic converter; and a dosing device being provided for introducing liquid urea as a reducing agent for the at least one selective catalytic converter into the bypass line.