摘要：AbstractIn the last years, the research effort of the automotive industry has been mainly focused on the reduction of CO2 and pollutants emissions. In this scenario, concepts such as the engines downsizing, stop/start systems as well as more costly full hybrid solutions and, more recently, Waste Heat Recovery technologies have been proposed. These latter include Thermo-Electric Generator (TEG), Organic Rankine Cycle (ORC) and Electric Turbo-Compound (ETC) that have been practically implemented on few heavy-duty applications but have not been proved yet as effective and affordable solutions for passenger cars.The paper deals with the analysis of opportunities and challenges of the ETC for a compact car, powered by a turbocharged SI engine. The ETC consists of a motor-generator unit (MGU) integrated into the turbo shaft that can operate either as generator or motor. In the paper the benefits achievable by the electric turbo-compound have been investigated by simulation analyses carried out by a dynamic engine-vehicle model, validated against steady-state and transient experimental data. The in-cylinder processes and friction losses of the engine are modelled by a black-box parametric approach while grey-box dynamic models are applied for intake/exhaust manifolds and turbocharger to simulate more realistically the effect of ETC on engine performance and fuel economy along vehicle transients.The simulations have been carried out considering standard driving cycles (i.e. NEDC, WLTC) and several ETC management strategies. The results evidence that significant improvement of fuel economy and CO2reduction can be achieved by suitable management of ETC operation, depending on engine speed and load and auxiliaries demand.
