Heavy Duty Diesel Engine (HDDE) are between the biggest contributors to CO2 emission and ambient pollution
as they are the most widely used technology for commercial vehicles and ship propulsion applications, as well
as, together with reciprocating gas engines, for small medium-size distributed stationary power generation.
New emission legislations in the on and off highway sectors, such as for example EURO VI and Tier 4 final,
regarding NOx and Particulate Matter (PM), are also becoming year by year more stringent.
For these reasons, in the last years, concerns about further engine development and efficiency improvement
are of primary importance and several technologies have been studied and implemented.
This review is meant to give an overview of the Organic Rankine Cycle (ORC) technology to recover wasted
thermal energy in Heavy Duty Diesel Engines (e.g. exhaust gas, EGR, coolant circuit, charge air cooling, oil
circuit) with particular focus on vehicle applications for on and off highway sectors (e.g. long-haul trucks, earthmoving
machines, agricultural tractors). In addition, multiple different engine operating profiles in terms of
torque and speed are gathered and reported for a variety of typical vehicles, in order to characterize the best
system design point for the chosen application
