Application of two stage turbocharging systems on large engines

A novel objective oriented methodology for marine engine–turbocharger matching

“…The engine2turbocharger matching can be a lengthy process for a new marine engine, due to the large number of the involved parameters, 8 which affects the engine transient response, especially at low loads operation, due to the turbocharging system lag. Alternative configurations were proposed for improving the engine performance and transient response including the sequential turbocharging, 9 the two-stage 10,11 turbocharging, the variable geometry turbine turbocharger, 12 the turbocharger cut-out (in cases with multiple turbochargers connected in parallel), 13,14 and the hybrid turbocharger. 15,16 Nonetheless, the single and parallel turbocharging systems are preferred for most of the marine engines, as they constitute solutions of lower complexity, thus imposing less challenges for their installation, control and maintenance.…”

Development of a physically-based simulation and diagnosis methodology for supercharging systems and its application on large scale marine diesel engines

“…Multiple stage turbocharging concepts are also starting to be evaluated as candidates for future powertrains, equipped with 2 Air Coolers (A/C"s) after each compressor stage. This strategy enables pressure ratios of over 10 to be achieved across both stages, making Miller cycle strategies feasible (early/ late inlet valve closure) [12] for BSFC and NOx emissions reduction.…”