| Summary: | 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. Tämän työn tavoite on arvioida jäänmurtajien ja jäätä murtavien offshore-alusten pakokaapupäästöjä eri nopeuksilla ja jään paksuuksilla. Tämän tavoitteen saavuttamiseksi tulee kehittää yksinkertaistettu laskentamenetelmä kunkin tutkimuksen kohteena olevan aluksen tehontarpeen määrittämiseksi eri olosuhteissa. Kehitetty ...
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