Research on multi-interval coupling optimization of vessel speed for energy efficiency

Abstract

By taking the YUKUN ship as the research object, this research aims to improve the energy-saving effect of the YUKUN ship. Through speed optimization, the value of the energy efficiency operation index (EEOI) is minimized. The effects of uncertainty factors and their mutual coupling on EEOI in the process of ship operation are analyzed. To obtain the design variables (ship speed) in the optimized design, the speed data of the round-trip voyage between the Dalian and Haiyang Islands are taken as the source data. The design space of the design variables is obtained using data analysis methods, such as time equidistantization of speed data, acquisition of stationary segment, data expansion based on cloud model theory and normal test hypothesis. The adaptive simulated annealing algorithm (ASA) is then used for deterministic optimization. 6σ analysis is used to analyze the reliability of the optimal solution, and 6σ optimization improves its reliability. The relationship between the uncertain factors (i.e. flow velocity [Vw], ship wet surface area [S], ship cargo loading rate [R]) and EEOI is examined. The interval analysis method is used to embed the uncertain factors into the double-layer nested optimization system to explore the effect of single uncertain factor and the coupling effect of multiple uncertain factors on EEOI. The results show that Vw and S can improve the energy-saving effect of EEOI, R significantly decreases the energy-saving effect of EEOI, and the coupling effect of multiple uncertain factors inhibits EEOI. This research is of great significance to energy conservation, emission reduction and reduction of operating costs in the process of ship operation.