Increasing energy efficiency in marine diesel-electric propulsion systems

Electrical propulsion systems have shown that, they can reduce fuel consumption and harmful exhaust gas emissions from ships. Studies have been carried out for many years to take advantage of electrical propulsion systems on different ship types. The studies generally consisted of short-distance shoreline ships, large passenger ships with high electricity needs, special purposes ships that require Dynamic Positioning (DP) or military ships. However, the increase in the efficiency of electrical equipment, the increase in environmental concerns arising from ships and the international restrictions imposed to take measures against this have led to studies that can have a wider usage area of electrical propulsion systems. In this thesis, having a Diesel-Electric (DE) propulsion system was simulated for an offshore container ship, and such a system was evaluated in terms of fuel consumption and emissions over three different scenarios. First of all, the ship's forty-day navigation information was obtained and the load profile was drawn. This load profile is adopted for the DE propulsion system, taking into account the losses of electrical conversions. By assuming that it performs the same operations as this container ship are simulated with a mathematical model for traditional DE propulsion system, a hybrid power sourced DE propulsion system using batteries, and a DE propulsion system that can adapt to zero emission ports. In the simulation, it is aimed to create the necessary configurations for the generators to operate at optimum load and to create a structure in which the batteries can contribute to the power balance. With the simulations made, the fuel savings varying between 2.9% and 10.38% and the reduction in emissions related to this in different scenarios for an offshore container ship are shown.