Abstract
The selection of a proper machinery system is one of the primary decisions to be taken during the ship design phase. Nonetheless, this selection is made challenging by the presence of a variety of alternatives, and by the limited data availability at the early stages of the design phase. An optimization framework is presented in this paper, supporting decision making at the earliest stages of the ship design process. The framework is suitable to perform the screening and the selection of optimal machinery configurations for a predefined ship operational profile, and it includes both linear and non-linear optimization routines. The results of the linear and the non-linear approaches are compared, and indications on what conditions are the most suitable for the application of one or the other approach are provided. Both approaches are tested for two case studies, a bulk carrier and a small cruise ship. The results indicate that both optimization approaches lead to the same layout of the machinery system, but to slightly different unit scheduling. This suggests that the use of the linear approach is suitable for design purposes, but less appropriate for operational optimization. In addition, the findings of the work suggest that the trade-off between fuel consumption and volume of the engines should be considered when selecting the machinery system for a ship.
Highlights
The results indicate that the two approaches led to almost the same unit scheduling, except for the sailing mode 2, where the hotel power is produced by the auxiliary engine 1 (6L20DF) in the mixed-integer linear programming (MILP) case, and by the auxiliary engine 2 (6L34DF) in the mixed integer non-linear programming (MINLP) case
The input parameters to the optimization framework were the information of a specific ship and a range of engine candidates to be used in the ship machinery system
The non-linear programming approach was extended to estimate the volume occupied by the machinery system, enabling multi-objective optimizations
Summary
As humanity faces the global threat of climate change, society needs to drastically reduce the emission of greenhouse gases (GHGs). Maritime transport currently contributes to about 2.7% of the global anthropogenic carbon dioxide (CO2) emissions [1], but this share might increase as a consequence of the de-carbonization of other sectors and in correspondence with an absence of actions in the shipping business. Ships are still almost entirely powered by fossil fuels. The International Maritime Organization (IMO) officially adopted an initial strategy aimed at reducing GHG emissions from shipping by 50% by 2050, compared to the levels of 2008 [2]. A sharp change in the way ships are designed and operated is necessary to reach this goal
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
