Abstract

This paper proposes a serial hybrid concept for an automotive powertrain running on re-newable ethanol. All transient power requirements are covered by a smart battery system with high power output at a moderate capacity, enabling the internal combustion engine to operate quasi stationary, requiring only 3-5 operating points to cover the average power. This allows for a significant increase in vehicle efficiency, even when considering the addi-tional energy conversion losses within a serial hybrid. AVL Cruise is used to determine the required operating points for WLTC and real-world driving, as well as the vehicle efficiency and emissions. A combination of 1D analysis and 3D CFD, in addition with engine testing, is used to develop the combustion solution. The innovative DI ethanol engine with turbulent flame jet ignition, via prechamber spark plug, has a compression ratio of 13:1 and is running at lambda 1.9 with a BMEP of 16 -18 bar and a speed of 1200 – 3000 rpm. The engine effi-ciency is between 42% and 44% and due to the low raw emissions, an oxidation catalyst and a SCR-System with moderate conversion rates are sufficient to meet the proposed Euro 7 limits.