The Influence of high efficiency Engines and Hybrids on Exhaust Systems
The continues increase of the efficiency of combustion engines together with the hybridization of drivetrains is influencing the Aftertreatment System including its Control Strategies and Diagnostics. The reduction of friction and mechanical losses, e.g. due to new lubricants and the reduction from 6 to 5 cylinders for commercial vehicle diesel engines, combined with optimized direct injection strategies, increased injection pressure and advanced fuels, allows the next generation of combustion engines again a tremendous increase in efficiency and so far, also a reduction in CO2 emissions. Increased efficiency in the combustion process itself and low losses in the engine, lead naturally to lower temperatures in the exhaust line. Combined with the exhaust gas energy recovery as well as the hybridization of the drivetrain this temperature decrease will require additional efforts for the exhaust gas after treatment in future. Current Technologies like SCR with liquid AdBlue could only be used in future with additional heating elements or will need to change to gaseous Ammonia to keep the current efficiency and conversion rates. New Catalyst and Filter Elements with ultra-low backpressure in the exhaust pipe are leading to new challenges as current and future Emission laws needs to be met including the correct and robust Diagnostics of these Aftertreatment Components and all emission relevant parts and thresholds. New technologies are needed like the direct measurement of the DPF soot loading with radio frequencies or NH3 Sensors to precisely control the Ammonia Slip for high conversion rates of SCR catalysts
Tematyka artykułu: Pomiary i kontrola emisji
Autor: Matthias Weber
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