摘要:
An exhaust gas system of a vehicular internal combustion engine comprises a plurality of exhaust gas catalytic converters having different working temperature ranges. Depending on the temperature of the exhaust gas the latter is directed to the one or those converters into whose working temperature range the exhaust gas temperature falls.
摘要:
An exhaust gas system of a vehicular internal combustion engine comprises a plurality of exhaust gas catalytic converters having different working temperature ranges. Depending on the temperature of the exhaust gas the latter is directed to the one or those converters into whose working temperature range the exhaust gas temperature falls.
摘要:
An exhaust system or an engine (12) includes a lean NOx catalytic device (18), and a heat exchanger (70) positioned upstream of the catalytic device (18). Control means (44, 46) controls a valve (36) to regulate exhaust gas flow through the heat exchanger (70) or along a bypass path (26). The heat exchanger (70) can cool the exhaust gases to ensure that the maximum operating temperature of the catalytic device (1) is not exceeded. During use, the heat exchanger (70) can be bypassed to allow high temperature purge cycles.