Optimal Aftertreatment Pre-Heat Strategy for Minimum Tailpipe NOx Around Green Zones
The efficiency of the aftertreatment system, in terms of its ability to reduce NOx, is highly dependent on the temperature of the system. Normally, the aftertreatment system is heated, and kept hot, by the hot exhaust gases from the engine. However, when the engine is turned off, this means that the aftertreatment system is cooled by the ambient air, and its efficiency eventually starts to go down. This becomes important, for example when cargo is loaded or off-loaded at a distribution hub, and for hybrids that might go all electric for extended periods. In this paper different strategies to deal with this problem is compared in a simulation study. The different strategies are: • Do nothing - Use the most fuel-efficient engine mode throughout the whole event.