Effects of an ORC Based Heat Recovery System on the Performances of a Diesel Engine

A smart way to reduce CO2 emission in transportation sector is to recover energy usually wasted and re-use it for engine and vehicle needs. ORC plant on exhaust gas of ICE is really interesting, but it has a significant impact on the exhaust line and vehicle's weight. The backpressure realized in the exhaust and the weight gain, in fact, produce a specific fuel consumption increase as well as an increase in the propulsion power: both terms could vanish the energy recovered. The paper discusses the effects of the pressure losses produced by an ORC plant mounted on the exhaust line of an IVECO F1C test bench engine. The interactions produced on the turbocharged engine have been experimentally investigated: the presence of an IGV turbocharger makes the effect of the backpressure not straightforward to be predicted and needed a full experimental testing of the group in order to understand its reaction and the net effect in terms of specific fuel consumption. The extra-weight of the unit completed the analysis in terms of the real effectiveness of the energy recovery and sets the boundaries of applicability of an ORC based recovery system.