The effects of using blended renewable diesel fuel (30% vol.),
obtained from Rapeseed Methyl Ester (RME) and Hydrotreated
Vegetable Oil (HVO), in a Euro 5 small displacement passenger car
diesel engine have been evaluated in this paper.
The hydraulic behavior of the common rail injection system was
verified in terms of injected volume and injection rate with both
RME and HVO blends fuelling in comparison with commercial diesel.
Further, the spray obtained with RME B30 was analyzed and compared
with diesel in terms of global shape and penetration, to
investigate the potential differences in the air-fuel mixing
process.
Then, the impact of a biofuel blend usage on engine performance
at full load was first analyzed, adopting the same reference
calibration for all the tested fuels.
Afterwards, the effects of a biofuel blend usage on brake
specific fuel consumption and on exhaust emissions were also
evaluated at 7 different part load operating conditions,
representative of the New European Driving Cycle.
Finally, soot-NOx trade-off obtained by means of EGR
sweeps were performed in the same operating points, in order to
gather detailed information about further possible emissions
benefits that could be achieved through a more extensive ECU
recalibration.