Comparative Assessment and Parametric Optimisation of Large Marine Two-Stroke Engines with Exhaust Gas Recirculation and Alternative Turbocharging Systems

Although the exhaust gas recirculation (EGR) technology has been proven effective to decrease marine engine’s nitrogen oxides (NOx) emissions, it is associated with a considerable fuel consumption increase and challenges engine–turbocharger matching. This study aims parametrically optimise EGR turbocharging system settings of large two-stroke engine objective obtaining highest efficiency whilst ensuring compliance prevailing NOx emissions limits. Two typical configurations investigated (baseline alternative) are modelled in GT-SUITE software. Parametric simulations performed rates up 40% along cylinder bypass 50%, simulation results analysed quantify impact operation on performance parameters. For baseline configuration, rate considerably deteriorates brake specific (BSFC), which attenuated by opening valve. The optimal combinations for each operating point identified both configurations. Following comparative assessment between two configurations, recommendations modes proposed, leading BSFC improvement region 0.7 2.9 g/kWh. provides insights operational optimisation engines equipped systems, contributing towards reduction environmental carbon footprint.