Euro 7/VII regulations are currently under discussion and are expected to be the last big regulatory step in Europe. From available documentation, it is clear the aim of further regulating the extended conditions of use which are still responsible of high emission events (e. g. cold start or altitude) as well as regulating secondary emissions such as NH3, N2O, CH4, Aldehydes (HCHO).
Even if not completely fixed yet, the EU7 limits will be challenging for internal combustion engines and even more for Diesel. Despite a consistent reduction of market share, Diesel engines are expected to remain a significant portion in certain sectors such as Heavy duty (HD) and Light-commercial vehicle (LCV) for some decades.
In order to reach the new limits being proposed, besides minimizing engine-out emissions, Diesel powertrain will need an aftertreatment system able to work at very high efficiency right after engine start and in almost every working and environmental condition.
The present work aims at evaluating different aftertreatment layouts in the context of most updated proposals issued by Consortium for ultra-low emission vehicle (CLOVE). During an extensive experimental campaign, different combustion strategies were tested on emission cycles deemed representative of European regulatory environment. Experimental engine out data were then used as input to catalysts kinetic models to build a walk towards Euro 7 CLOVE proposed limits. Starting from a Euro 6d capable aftertreatment layout featuring a close-coupled DOC (Diesel Oxidation Catalyst) and SCRoF (Selective Catalytic Reduction on Filter) and underfloor SCR (Selective Catalytic Reduction) and AOC (Ammonia Oxidation Catalyst), different aftertreatment layouts were evaluated, including a first catalyst with NOx storage function and different electrical heating options (both 12V and 48V).
Results of simulation activity will be presented, and most promising layouts will be discussed both in terms of performance and in terms of ease of implementation on vehicle.