A novel objective oriented methodology for marine engine-turbocharger matching

The matching of the turbocharging system with a marine engine is an essential undertaking due to the turbocharger effects on the engine performance, emissions and response, whilst the limited data availability during the ship design phase renders it challenging. This study aims at developing a novel methodology for the matching of a single turbocharger and multiple turbochargers connected in parallel with marine engines. This methodology employs a compressor parametric modelling tool and a zero-dimensional engine model, whilst taking into account the engine operational profile and the turbocharger components flow limitations. The compressor parametric tool is used for the generation of a database with compressor families that can be investigated during the matching procedure. The model of one engine cylinder block is used for mapping the engine performance parameters at a wide engine operating envelope by developing response surfaces. The developed methodology is implemented for the case study of the turbocharger matching with the propulsion engine of an Aframax tanker. The annual fuel consumption and the engine load diagram upper limit are employed as the main objectives for the selection the turbocharging system. The derived results demonstrate that the effective turbocharger matching results in reducing the engine brake specific fuel consumption up to 5%. The identified turbochargers led to the reduction of the ship annual fuel consumption in the range 1.3%–5.3% compared to the reference engine, whilst providing a more expanded load diagram. This study overcomes the limitations of the manual engine turbocharger–matching process providing decision support on the effective turbocharger matching to satisfy contradictory objectives.