The Study On The Capability Of Main Propulsion Plant In The Renewed Wind-assisted Ship

With the fast increase of national economy and speed-up of urbanization process, the demand of energy resources is climbing according to the estimation of the energy experts, fuel which is used by shipping business makes up a very big part of the whole world's fuel consumption. Under the current background of high international crude oil price, the running of ships faces challenges on the cost as well as the huge pressure from energy conservation and emission reduction, especially, after the MEPC 58th section, on which CO2 design index for new ships was replaced by the new energy efficiency design index (EEDI), the focus of debate of international maritime community rapidly. The development of EEDI highlights kinds of measures of improving ships'energy efficiency, encouraging the shipyard, ships designer and equipment manufactures to improve ship's energy efficiency with these measures, to promote the technical progress and innovation.Under this situation, wind-assist system as the auxiliary power is applied to ships more and more, however, the installation of wind-assist device on the existing ships has an affect not only on the sailing posture, but also on the performance of main propulsion plants. To keep main engine under good working conditions, it is necessary for us to analyze the properties of the main propulsion plants, optimize main engine's operation by certain means.Firstly, with the use of Fluent 6.0, this research calculated the boost pressure generated by the interaction of wind and sail, and then evaluated the propulsion upon ships. Secondly, based on the analysis of propeller properties and ships assistance when sails were installed, this research evaluated the reduction of speed and power of the main engine and then figured out the main engine's operation area under different wind speeds and sailing conditions. Thirdly, this research analyzed the changes of and effects on kinds of properties of main engine after power reduction, optimized main engine's operation according to different operate condition, and developed scientific operation and management mode. Finally, this research evaluated the economic gain of the target ship after main engine power reduction at the point of fuel and emissions. Taking main engine itself as the fundamental point, this research analyzed the effect of main engine's power reduction on the properties of the propulsion plants after wind-assist device installed on ships, developed a series of operation method which accustomed to main engine with power reduction, and calculated the total economic benefits in the end. This research provided the operation and management advices for the main engine on the refit ships. It will be helpful for the design and building of wind-assist ships.