Renault Trucks, a member of the Volvo Group, is exploring the use of a Rankine-cycle-based waste-heat-recovery system for its long-haul trucks.
The Rankine cycle is a simple closed thermodynamic cycle that converts heat from an external source into work. With the system, enthalpy of the vehicle’s exhaust gases is recovered and then converted into electricity by a generator incorporated into the turbine. The electricity would be used to supply electrical components and auxiliary equipment on the vehicle, so as to cut fuel consumption by reducing the load on the alternator.
The Rankine system makes it possible to generate several kilowatts of electricity. Ultimately, the Rankine system is capable of reducing long distance vehicle fuel consumption by between 5% and 10%, says Renault.
Almost 30% of a vehicle’s full tank of fuel is dissipated in the form of heat in the exhaust gases. This is a total waste. The Rankine system enables us to recover some of the energy contained in these exhaust gases and convert it into electricity.—Dimitri Lortet, engine development project manager