T3.2 Conceptual Design of H2 Based Alternative System: Progress update

The SAFeCRAFT project is dedicated to advancing the safety and adoption of Sustainable Alternative Fuels (SAFs) in maritime transport. By integrating, validating, and demonstrating SAFs on board oceangoing vessels, the project seeks to address critical challenges regarding their safety, technological maturity, and economic viability.

One of the SAFeCRAFT specific outcomes is demonstrator retrofit of an H2 GenSet onboard a 180,000 DWT Capesize Bulk Carrier. This GenSet will use gaseous hydrogen for the vessel’s auxiliary/propulsion power needs, thus reducing the Carrier’s carbon footprint during the operations.

In Task 3.2 of the SAFeCRAFT project, the Conceptual Design of H2 Based Alternative System draws from specific previous outcomes of a sister project, LH2CRAFT. The latter has already developed the next generation of sustainable, commercially attractive and long-term storage and long-distance transportation of Liquid Hydrogen for commercial vessels. Although, the task focuses exclusively on H2-fueled vessels and involves a comprehensive study across four ship types: containerships, tankers, RoPax vessels, and cruise ships. Both retrofit and newbuilding approaches will be considered, with a further distinction based on powertrain options. The first powertrain option under consideration combines an Internal Combustion Engine (ICE) with a Power Take-In (PTI) system, while the second involves the use of Fuel Cells supported by battery block(s). Various scenarios will be evaluated by using Key Performance Indicators (KPIs), which have been developed in other tasks of the project. This assessment forms part of Task 3.4, which also examines alternative fuel options such as Ammonia (through partial or full ammonia cracking) and Liquified Organic Hydrogen Carriers (LOHCs). Furthermore, the outcomes of Task 3.2 will serve as crucial input for conducting a detailed engineering study in subsequent tasks.

Hydrogen Storage and Bunkering Technologies

LH2CRAFT developed a prototype tank that satisfies LH2 insulation requirements, IMO regulations and Classification Society guidelines. The basic insulation unit structure includes liquid and gas tight barriers to prevent leakage and safely store LH2, insulation materials to improve transportation efficiency and fastening members to hold such barriers and insulation materials on the hull structure. A similar tank will be used for the SAFeCRAFT demonstrator vessel. Similar control and monitoring systems will also be used for the SAFeCRAFT demonstrator, as they have reliably detected and managed the rate of hydrogen boil-off in the LH2CRAFT demonstrator.

System Integration Protocols

The system integration efforts that took place during LH2CRAFT resulted the development of hydrogen fuel system installation guidelines. These give guidance on placing tanks in locations that minimize risk to the crew and vessel operations, as well as on the integration of piping systems that can handle the extreme cold of liquid hydrogen while maintaining structural integrity under maritime operating conditions. These guidelines are now carried over to the SAFeCRAFT demonstrator so that the layout and assembly of hydrogen fuel components doesn’t conflict with existing systems and meets accessibility standards for maintenance and emergency handling.

Safety and Risk Assessment

LH2CRAFT developed comprehensive risk assessments for hydrogen storage and bunkering in maritime environments, including dynamic simulations of potential leak scenarios and their impacts on ship safety. These risk assessments helped establish emergency response strategies not just for the LH2CRAFT project, but for the SAFeCRAFT project as well. Leak detection systems, automated shut-off valves, and emergency venting systems have been designed to handle the larger volumes of hydrogen expected on the SAFeCRAFT demonstrator vessel.

Regulatory Compliance and Certification

Drawing on experience gained in LH2CRAFT, relevant documentation will be developed and tests ensuring the Approval in Principle by classification societies will be conducted. As with all cutting-edge projects, SAFeCRAFT will go beyond LH2CRAFT as the real-world demonstrator will contribute to the development of guidelines for hydrogen-fuelled vessels.

By leveraging the above expertise gained by LH2CRAFT, SAFeCRAFT’s Task 3.2 achieves technical viability and regulatory compliance faster, thus pushing forward the adoption of SAFs in the maritime industry.

Model Development

One of the most critical components of this task is the development of a model for the integrated energy system of H2-fueled concept vessels. For both powertrain options, the structure of the integrated energy system significantly differs from conventional systems found on existing ships. Synthesis of the energy system requires a comprehensive analysis of its parameters and the integration of new systems essential for H2-fueled vessels. The results will be derived from multiple simulations, leveraging the developed system model and considering the operational profile of the vessel in question. The model will be implemented using advanced software tools, capable of performing a wide range of calculations efficiently, ensuring both accuracy and robustness.

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