Reducing consumption by recovering heat from exhaust gases
As part of its “All For Fuel Eco” initiative, Renault Trucks is stepping up its research into new technologies with the potential of generating further fuel savings in the future. In particular, research is underway into recovering energy from the exhaust based on the Rankine cycle and adapted to long distance vehicles, which could reduce consumption by several percentage points.
Renault Trucks is focusing all its energy on a key objective – to save fuel. Its Optifuel Solutions, developed by Renault Trucks as part of the "All for Fuel Eco" initiative, already make it possible to reduce consumption by as much as 15%.
But research is ongoing. Renault Trucks is now working on incorporating a system of recovering the energy contained in exhaust gases, known as the Rankine cycle, into long haul vehicles. This is designed to produce electricity to supply electrical components and auxiliary equipment on the vehicle, so as to cut fuel consumption by reducing the load on the alternator.
The system based on the Rankine cycle makes it possible to convert the thermal energy into electrical energy. The enthalpy of the vehicle's exhaust gases is recovered and then converted into electricity by a generator incorporated into the turbine. "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" explains Dimitri Lortet, engine development project manager. "The Rankine system enables us to recover some of the energy contained in these exhaust gases and convert it into electricity".
The Rankine system makes it possible to generate several kilowatts of electricity. "It is important to note that the basic energy being used, that of the exhaust gases, is free" stresses Colin-Yann Jacquin, product strategy manager for alternative energies. Ultimately, the Rankine system is capable of reducing long distance vehicle fuel consumption by between 5% and 10%.
This is a project which highlights Renault Trucks' ambition to stay in the forefront of research into new technologies.