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Item type:Publication, Access status: with files , Use case: layout and control optimization of a hybrid ship power system in the early design stage ; system Integration & hybridization(2025-05-19); ; With the trend in shipping industry to switch primary fuels to renewable low flash-point alternatives, the abilities of internal combustion engines of handling transient loads are reduced. This has a major impact on maneuverability of ships and is therefore crucial for regulatory, contractual and safety aspects. Hybridization of the power systems including energy storage and shaft alternators can compensate for disadvantages by providing additional degrees of freedom, making stable control of the power system essential. The decision for an appropriate power system and its control system needs to be made in early design stage to avoid increased project costs for late changes. Thus, fast and accurate simulations based on limited project data are required. The simulation tool HyProS depicts a software solution to estimate the performance of shipboard power systems for such use cases. Part of it is a generic mean-value model of medium- and high-speed engines, which is parameterized with e.g., project guide data. The focus of this work is on optimizing control strategies for a typical use case with respect to different objectives using HyProS. The power plant architecture envelopes hybrid power supply and hybrid propulsion. The influence of different control settings for major components on the system behavior is worked out and considered for designing the controllers for the objectives of high dynamic performance and overall efficiency. The results are highlighting two things: the capabilities of system hybridization for optimizing vessel operation for different objectives and the benefits of fast simulations in early project phases. The generic engine model allows for a fast simulation setup and provides an advanced understanding of engine limits and their influence on maneuverability compared with models with lower fidelity.Publicationtype: Conference Paper not in Proceedings78 49 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Comparison of fuel properties of alternative drop-in fuels with standard marine diesel and the effects of their blends(2023-10-10); ; ; Drop-in fuels are biofuels or synthetic fuels designated to be blended with conventional petroleum-derived hydrocarbons. These alternative fuel blends can be used without major modifications of the engine or the fuel system. Thus, the use of drop-in fuels offers the marine sector a good first opportunity to reduce the carbon footprint and other emissions. This work investigates the miscibility and compatibility of different potential drop-in fuels with standard distillate marine diesel in order to provide an initial outlook on possible use in the maritime sector based on their fuel characteristics. The five drop-in fuels Fatty acid methyl esters (FAME), Oxymethylene ether (OME), Hydrotreated vegetable oils (HVO), Fischer-Tropsch diesel (FTD) and a pyrolysis oil (HDO) were mixed at 10, 30 and 50 % with standard marine distillate diesel and the physical and chemical properties, the distillation curves and the corrosion stability as well as the storability were analysed. All drop-in fuels can be blended with DMA. Due to the chemically different composition of OME, the distillation curve of the blends significantly differs from the distillation curve of DMA, which should be taken into consideration when using these new alternative blends. Furthermore, the blends of OME and FTD show an unexpected corrosion, which is not observed in the pure drop-in fuels. This is expected to have a considerable influence on the engine operation as well as on the storage.Publicationtype: Journal Article77 173