Session: 06-04-04 Marine Engineering and Technology IV

Paper Number: 126634

126634 - A Design by Optimisation Approach for Hybrid Propulsion Systems Sizing Using Actual Sailing Profiles 

Mitigation of climate change requires transportation sector to reduce its carbon footprint, hence improve its energy efficiency. In that direction electrification of ships is taking place at a fast pace. Especially ships with hybrid propulsion and power supply are considered promising alternatives to ships with typical diesel mechanical propulsion. Nevertheless, an increased number of parameters crucially influences the resulting energy performance and carbon footprint of hybrid ships. Such parameters are the electrical hotel load, individual sailing profiles, selection of component maker, volume and weight restrictions, but also the additional financial cost, both capital and operational. The energy performance of new designs for most ship types in the maritime industry is examined with the regulated Energy Efficiency Design Index (EEDI), though its limited consideration of one design point in calm water conditions and installed rated power is characterised as insufficient or even dangerous by many authors. Other industries as automotive and aviation have already adopted measures that assess the energy efficiency of new designs over defined operating cycles such as the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC) or the Landing and Take-Off cycle (LTO). This paper proposes a new methodology for the case of sizing the hybrid propulsion system of the ‘Holland class’ ocean patrol vessels of the Royal Netherlands Navy. This methodology uses high frequency operational-data logged by the automation system of the vessel to get the actual sailing profiles of three individual vessels. A state of the art digital twin approach leveraging data-driven and first principle models of the vessels’ energy system, developed by the authors in a previous stage, is used to predict fuel consumption and carbon intensity of ship operations under actual operational and environmental conditions. The developed optimization methodology is compared to the benchmark methodology integrating common assumptions at the design stage and regulated procedures. The solution of the resulting multi-objective optimisation problem demonstrates a carbon intensity improvement of 5% to 10% by optimising over actual sailing profiles.

Presenting Author: Nikolaos Vasilikis Delft University of Technology

Presenting Author Biography: Nikolaos Vasilikis is a PhD researcher with the Maritime, Transport and Technology department at Delft University of Technology, working towards the sustainable design and operation of ships. His research focuses on methodologies for the energy performance analysis and optimisation of ship energy systems, utilising both data-driven and first principle modelling techniques. He received his diploma in Naval Architecture and Marine Engineering from the National Technical University of Athens in 2016.

Authors:

Nikolaos Vasilikis Delft University of Technology
Rinze Geertsma Netherlands Defence Academy
Luca Oneto University of Genoa
Andrea Coraddu Delft University of Technology