Abgasanlage für eine Brennkraftmaschine mit einem Abgas-Turbolader

摘要

An exhaust-gas unit (7) for an internal-combustion engine (1) with an exhaust-gas turbocharger (3) is provided with three-way catalysts for de-contaminating the exhaust gases. In order to shorten the delay before the beginning of the cleaning of the exhaust gases when the internal-combustion engine is started, a first catalyst (13) continuously traversed by the exhaust gas is arranged in the exhaust-gas line downstream of the turbocharger (3) and a second catalyst (11) traversed only periodically by the exhaust gas is arranged upstream of the turbocharger (3). The second catalyst (11) is traversed only until the exhaust-gas unit (7) has reached a pre-determined temperature, after which control valve (20) is opened so that this catalyst is by-passed.