Browsing by Author "Stenberg, Arttu"

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  • Calculation method development for icebreaker exhaust emissions
    (2012) Stenberg, Arttu
     School of Engineering | Master's thesis
    This work aims to evaluate exhaust gas emissions of icebreakers and ice-breaking offshore vessels at different speeds and ice thicknesses. To achieve this, the goal is to develop a simplified calculation method to evaluate the power demand of each vessel analysed in the study. The developed method of calculation adds the experienced ice resistance and power demand in open water of each ship together. The ice resistance formula is derived from the Lindqvist-formula and from published full-scale observations of different vessels. The open water power demand is estimated based on analysis of published full-scale data. The results for ice resistance and power demand given by the calculation method are extensively compared to published full-scale measurements. The exhaust gas emissions of icebreakers and ice-breaking vessels are calculated on the basis of calculated power demand by using emission factors of major exhaust emission components. The result is indicative emission levels as a function of velocity in three different ice thicknesses, which can be considered as an average for today's modern ships without exhaust gas after-treatment. Emission ratings can be used to evaluate modern icebreaker's and ice-breaking offshore vessel's average exhaust emissions under various conditions when the power demand and the ship's operating profile and prevailing ice conditions are known. The results can be used in performance and environmental assessment of new ships compared to the current fleet. The work provides new information of the link between the emissions from ships, the environmental conditions and the mode of operation, what can be used as a basis for new emission regulations and emission indices.
  • Feasibility study on hydrogen fuel systems onboard cruise ships
    (2024-06-10) Ibrahim, Amin
     Insinööritieteiden korkeakoulu | Master's thesis
    This thesis explores the feasibility of integrating hydrogen fuel systems into cruise ship design, responding to the maritime industry's urgent need for sustainable and environmentally friendly solutions. The primary focus is on assessing whether and how hydrogen can serve as a viable alternative fuel to traditional diesel and liquefied natural gas (LNG) systems. Employing a combination of literature review, scenario planning through the Delphi method, and a case study of a reference vessel provided by Meyer Turku, this research examines the technical, regulatory, and operational aspects of adopting hydrogen technologies into cruise ship design. The study compiles hydrogen's properties, system integration challenges, and safety considerations, comparing them against conventional fuels while evaluating the impact on ship design and to the vessel’s operational efficiency. The chemical and physical properties of hydrogen greatly affect its use as a marine fuel, such as energy density, storage requirements, light weight, and flammability. The study highlights the challenges of storing hydrogen in both compressed and liquid forms onboard. The energy density of conventional gas fuel, LNG, is 2,6 times higher than that of liquid cryogenic hydrogen and 4,9 time of gaseous hydrogen in 300 bar storage tanks. Therefore, it can be expected that same endurance capacities are near impossible to be achieved in 100% hydrogen storage, without sacrifices in vessel’s economical capacities, i.e., number of cabins or passenger experience activities. Utilization of gas blend systems or alternative power production systems also affects both the light weight and net volume of the vessel greatly. Use of alternative stationary power production could be used to decrease total weight born from different ship machinery subsystems significantly. While hydrogen technology is advancing, its technical maturity varies significantly across different applications and components. For hydrogen systems to be feasible on cruise ships, substantial advancements are needed, particularly in the areas of storage, safety, supply of fuel converters and system integration. Specific evaluation should be made for long range ship operations of large vessels, due to the low energy density of the fuel.
  • Ro-Pax-aluksen lastikannen konstruktiomateriaalit
    (2009) Stenberg, Arttu
     Insinööritieteiden ja arkkitehtuurin tiedekunta | Bachelor's thesis
  • Techno-economic analysis of passenger ship LNG system implementations
    (2023-01-23) Eriksson, Sebastian
     Insinööritieteiden korkeakoulu | Master's thesis