High efficiency two stroke opposed piston engine for plug-in hybrid electric vehicle applications: Evaluation under homologation and real driving conditions

The potential of plug-in hybrid electric vehicles (PHEV) to reduce greenhouse gas emissions highly depends on the vehicle usage and electricity source. In addition, the high costs of the battery pack and electric components suppose a challenge to the vehicle manufacturers. However, the internal combustion engine complexity can be reduced due to its lower use as compared to the no-hybrid vehicles. This work evaluates the use of a new opposed piston 2-stroke engine, based on rod-less innovative kinematics, in a series PHEV architecture based on rod-less innovative kinematics along different driving routes in Europe. A 0D-vehicle model fed with experimental tests is used. The battery size is optimized under homologation conditions for two different vehicle types. The optimum case is tested in several real driving conditions under different vehicle modes and battery states of charge. The main contribution of this work is the demonstration of the potential to reduce the vehicle CO2 emissions and cost with an innovative 2-stroke engine. The results show that 24 kWh is the optimum battery size for both vehicle platforms. Charge depleting mode shows 70% of CO2 tailpipe reduction in urban cycles and 22% in long travels compared to the no-hybrid version. Charge sustaining mode results show a CO2 tailpipe reduction of 20% in urban cycles and 2% in long distance travels with respect to the no-hybrid version. In spite of the CO2 contribution of the battery manufacturing, the results show a reduction of LCA CO2 emissions in 52% in charge depleting and 7% charge sustaining against the no-hybrid case.

Automated summary

This study evaluates the potential of reducing vehicle CO2 emissions and costs by applying a new opposed piston 2-stroke engine in a series PHEV architecture on different driving routes in Europe. The results show that 24 kWh is the optimum battery size for both vehicle platforms, and significant emission reductions can be achieved under different driving modes and battery states of charge.