Engine oil warm-up through heat recovery on exhaust gases - Emissions reduction assessment during homologation cycles

In this paper, the Authors investigate the effectiveness of the waste heat recovery on the exhaust gases, to speed up the lubricant oil warm up, effective immediate after engine ignition and thus, with little or no delay on the start of NEDC homologation cycle. The experimental activity, performed on a turbocharged engine (F1C 3L IVECO), starts with the setting up of a proper oil circuit and exhaust line layout, to allow the exhaust tailpipe to include a shell and tube heat exchanger for heat recovery. The unsteady heat availability on the exhaust gases, along with the variability the mass flowrate experiences during the NEDC cycle represents a major variable to account for in the heat exchanger selection and design. All interactions between the modified oil circuit, engine, coolant circuit and the exhaust line needed to be evaluated as well. Significant reduction of fuel consumption and pollutant emissions have been experimentally demonstrated.