This paper presents fast time-domain propulsion system simulation models for the Duisberg Test Case (DTC) post-Panamax container vessel using both diesel and ammonia as a fuel. The paper also provides first results of a ship integration study, demonstrating how the innovative combined SOFC- ICE AmmoniaDrive power plant could be integrated into the ship design.
With the first propulsion system model presented, voyages of the DTC container vessel are simulated while operating on regular marine diesel fuel, i.e., VLSFO, in a regular marine two-stroke diesel engine. In other words, this model provides voyage simulations of the current situation for comparable vessels. The propulsion system model is then converted, using crude but effective assumptions, to simulate ammonia-diesel operation of the same vessel, mimicking a situation in which the ship, or its main engine, is retrofitted to operate on ammonia-diesel. In this model, the ship has the same direct-drive propulsion system as before, with the same main engine and power output.
After presenting the results for the current situation and a potential near-future situation of ammonia- diesel operation for the DTC container vessel, a new propulsion system model is presented, based on the so-called AmmoniaDrive power plant concept. In this concept, ammonia is used as a fuel for a solid oxide fuel cell, producing hydrogen-rich anode off gas and electric power for the ship’s systems and a part of the required propulsion power. The hydrogen in the AOG is used as a combustion promoter in a main propulsion engine that provides the majority of the required propulsion power using ammonia as primary fuel, hydrogen from the AOG as a secondary fuel and a very small amount of HVO diesel pilot fuel as ignition source using Diesel’s Compression Ignition concept. The results of this first, early version of a AmmoniaDrive Propulsion, Power and Energy (PPE) system model are presented, after which the integration of such a system in the ship design is investigated by implementing the ammonia storage system as well as the main AmmoniaDrive power plant system components in the ship envelope of the DTC post-Panamax container ship. The impact on the amount of containers that can be carried by the vessel is modest, with only ~3.5% less cargo carrying capacity than the current diesel-fueled container vessel. Due to the crude assumptions made and the differences in the two models, it is not yet possible to quantify the decrease in ammonia consumption of the ship with AmmoniaDrive power plant compared with the ammonia-diesel fueled ship. Harmful emissions are potentially reduced by more than 95%. This is not only the result of switching to ammonia as primary fuel, but also because of a homogenous charge compression ignition, with flame propagation as main combustion principle, in the future ammonia-hydrogen marine IC engine.