Parametric investigation of a large marine two-stroke diesel engine equipped with exhaust gas recirculation and turbocharger cut out systems

Albeit the exhaust gas recirculation (EGR) is widely used to reduce nitrogen oxides (NOx) emissions from large marine two-stroke engines, several challenges emerge for engine–turbocharging system matching considering contradictory requirements of engine and its subsystems operation. Such become more pronounced in complex configurations that include parallel turbochargers EGR along with cut out bypass branches. This study aims at parametrically investigating a equipped an system, two different size, The turbocharging characteristics are selected targeting minimisation specific fuel consumption whilst ensuring compliance respective NOx limits satisfying imposed constraints compressors A detailed model zero/one dimensional type developed GT-SUITE software simulate investigated subsystems. Simulation runs performed investigate four turbocharger varying capacity ratio under various operating conditions terms rate load. simulation results analysed reveal impact selection performance parameters. Furthermore, modulation schemes blower speed control, cylinder overcome mismatch on components flow rates avoid operational issues. derived demonstrate lowest weighted BSFC achieved case 70:30 between small turbochargers, operation associated 2.6% penalty BSFC. control found sufficient compressor overspeed high loads exhibiting lower penalty, whereas appropriate controlling low loads. contributes delineating underlying parameters interactions provides recommendations procedure.