Workflow design methodology for ORC system dedicated to waste heat recovery from the engine coolant of commercial vehicles

Road transport is today the biggest contributor to CO2 emissions in transport (75% of transport total CO2 emissions) (IEA, 2019). Commercial vehicles, including Heavy Duty (HD) trucks, account for a significant contribution mainly due to their important mileage. In France for example, the 650 000 trucks registered represent 1.5% of all vehicles but 27% of their overall CO2 emissions. The new European CO2 regulation aims to reduce road vehicles CO2 emissions by 30% in 2030. Starting from 2021 all new light vehicle registration must comply with a maximum fleet average emission limit of 95 gCO2/km. For HD trucks, a target limit in gCO2/ton.km will be enforced starting from 2025. Electrification with batteries appears today as a reasonable way to reduce CO2 emissions for light vehicles; many prospective studies highlight this market trend (ADEME, 2018) and the change is already underway. Yet, for long mileage and heavy commercial vehicles, using conventional internal combustion engines (ICE) with low carbon content fuels (biofuel or hydrogen) or hydrogen fuel cell (FC) combined with electric powertrains seems to be more in alignment with vehicle range constraints. For these commercial vehicles, for which low carbon mobility is necessary, waste heat recovery (WHR) appears to be relevant to improve fuel consumption and reduce total cost of ownership (Gravel, 2019), (Reiche et al., 2020). In this article, a cost-driven approach using low temperature WHR is proposed. It is based on an electric organic Rankine cycle coupled with the vehicle cooling circuit as a heat source.This solution offers a safe, lightweight, and low-cost module compatible with both conventional ICE and low temperature Proton Exchange Membrane Fuel Fell (PEMFC) technology, which is investigated for the future decarbonized hydrogen mobility. Simulation results highlighted that this ORC solution can break even within 2 years for northern European conditions with the current hydrogen cost trend and can be improved thanks to the split cooling radiator architecture proposed.     «

Road transport is today the biggest contributor to CO2 emissions in transport (75% of transport total CO2 emissions) (IEA, 2019). Commercial vehicles, including Heavy Duty (HD) trucks, account for a significant contribution mainly due to their important mileage. In France for example, the 650 000 trucks registered represent 1.5% of all vehicles but 27% of their overall CO2 emissions. The new European CO2 regulation aims to reduce road vehicles CO2 emissions by 30% in 2030. Starting from 2021 all...     »