A Compact Temperature Control System for Lean Exhaust Gas to Improve Conversion Performance of NOx Aftertreatment
A compact exhaust gas temperature control unit is presented. The unit was fitted to a gasoline direct injection production car together with a modified exhaust system. It was shown that it was possible to keep the exhaust gas temperature within the lean operational NOx temperature window of typical NOx absorption catalysts for the whole European drive cycle. This should improve the lean NOx conversion of such a catalyst system significantly. It was shown that the standard vehicle cooling system should be able to cope with the additional heat input from the temperature control unit without major modifications.