AbstractsPhysics

BackgroundThe environmental consequences, caused by global emission of green house gases (GHG), have received increasingly concern in recent years. CO2 emissions from the maritime sector represent 3,3% of the world’s total CO2 emissions and are forecast to increase the next decades. To meet the new and stricter regulations on emissions, the International Maritime Organization (IMO) has announced that by 2015 the regulations known as “Tier III” will take effect in the emission controlled areas (ECA), and globally by the year 2020. They are currently debating technical, operational and market-based measures for reducing GHG emissions from the shipping industry. Hybrid power systems, which is a power system combining power production and energy storage, have been used in several industries and have received particular interest in the power production and car industries. Introducing it to power production onboard ships, the performance of the vessel can be improved and the emission of GHG can be reduced. Overall Aim and FocusThe overall objective of this thesis is to identify the cutting point between selecting hybrid power systems which combine energy production with energy storage capacity and diesel electric systems based on operational profiles and external influences such as cost, route, distance, weather conditions, maneuvering and type of operations. MethodThis thesis is a research of the influencing factors on selection of the most efficient machinery solutions for vessels with complex operational profiles. The first part of the report is a review of diesel electric power and propulsion systems, and state of the art configurations of it, which have been proven able to handle variations in load in an efficient manner. The influencing factors, such as operations to perform, weather conditions, emissions and rules and regulations, have been evaluated and described in order to create a platform for supporting the decisions made when selecting a machinery system based on the planned operational profile of the vessel. A stepwise method has been made to evaluate the influencing factors up against the operational profile. The first step is a simple overview of the operational profile to evaluate the degree of variation in operations and loads. Further on, the power demands in the planned operations are evaluated with focus on the possible dynamic loads. Finally, a screening process is presented to evaluate whether a hybrid of diesel electric and energy storage configuration is beneficial for a type of ship, compared to a pure diesel electric system. To estimate the potential economical benefits of hybridization compared to a diesel electric configuration, a simple calculation on savings in lifetime costs is conducted as the fourth step.ResultsThe ability of the vessels machinery to handle the dynamic loading picture during specialized operations in an efficient matter is of the utmost importance. Especially regarding operating costs, not only for the fuel consumption, but also the maintenance cost and…