Exhaust gas recirculation (EGR)

One approach to complying with the new emissions limits is to incorporate cooled exhaust gas recirculation (EGR). This involves extracting a portion of the main exhaust flow between the engine outlet and the turbine, cooling it in a special heat exchanger, and feeding it back to the intake air downstream of the charge air cooler. The combustion temperature in the engine is thereby lowered, thus reducing the formation of nitrogen oxides (NOx). One outstanding feature of MAHLE’s laser-welded exhaust gas heat exchangers is their excellent corrosion resistance. We also offer switchable exhaust gas heat exchangers featuring a bypass section integrated into the cooler housing. To keep pollutant emissions at a constantly low level, the bypass disables the recirculated exhaust gas cooling function in certain driving situations, e.g., during the cold start phase.