The International Maritime Organization (IMO) has developed new and stricter rules about environmental
impact of big vessels. Those rules are going to widen significantly the so called Emission Controlled Areas (ECA)
and to generally gain more control over pollution levels over the seas.
The solution that most ship-owners are going to prefer is most likely to be the implementation of pollutant
emissions reducing systems, such as Scrubbers and Selective Catalytic Reactor Systems, to dampen emissions
produced by the present propulsion systems, based on Internal Combustion Engine (ICE) which burns the cheap
but polluting Heavy Fuel Oil (HFO).
An alternative solution, based on the adoption of Gas Turbines (GT) in the propulsion system, fuelled by
Marine Gas Oil (MGO), can be taken into account, allowing considerable savings in weight and space occupied
and lover NOx as well as SOx emissions than those of ICEs, even if with a loss in the engine efficiency (Armellini
et al., 2018).
In this paper, the possibility of using simultaneously ICEs and GTs as well as the use of trigeneration system is
analyzed, with the aim of exploiting the positive feature of both the engine systems. The paper provides a
quantitative comparison among different hybrid engines configurations (ICEs and GTs working together) making
reference to a large cruise ship as a real case. Considering a cruise ship rather than a cargo ship implies an
important and time-dependent thermal energy demand, so that an onboard trigeneration system may result a
convenient solution.
