ABSTRACT

Future emission norms will focus on reduced idle and more aggressive driveaway strategies to further limit the cold start emissions of Gasoline engines in all geographies. Europe will likely be the first with EU7 RDE and will be followed by China VII and revisions to SULEV standards in the USA.

One promising solution is the use of Secondary Air Injection (SAI) for “cold start”. The current industry standard is to use low power secondary air pumps, which are limited to catalyst heating strategies under engine idling conditions. However, for dynamic boundary conditions, the SAI source should be controllable precisely to regulate the exhaust lambda and at the same time be powerful enough to operate against high exhaust back pressure.

Electric boosting products, E-Compressors & E-Turbos, fulfil the SAI requirements of future emission regulations comfortably. Once the catalyst heating strategy is completed, they function as regular electric boosting devices, to improve engine efficiency and reduce emissions under normal operation.

In this paper, the various layouts of E-Compressors & E-Turbo enabling SAI and electric boosting are discussed.