Research On Speed Optimization For VLCC And Energy Efficiency Analysis

As an important decision of tramp operation management,speed of ship is affected by ship technical conditions,travelling environment,climate conditions,shipping market and other factors.Reasonable speed optimization will be able to enhance the economic benefit of shipping company,increase energy efficiency of ship,and enable shipping company to maintain a strong competitiveness in the rival market.The crude oil is an important resource,which plays an important role in development of national economy,so oil trade influences the development of economy in every country.As a derivative demand of oil trade,tanker transportation is an important part of international shipping market,and the most economical mode of transportation of imported oil carriage is use of Very Large Crude Carrier(VLCC).Based on summarizing and analyzing research on speed optimization and other related areas,the research of the problem of ship speed optimization and energy efficiency of single VLCC in voyage charter contacts had been investigated in this article,and measures of marine power plant management were proposed.First of all,two mathematical models for ship speed optimization based on voyage daily economic benefit and voyage economic benefit were respectively established in this reserach,with the maximization of voyage daily revenue or voyage revenue as the objective,which considered main factors that affecting optimal speed such as voyage income,voyage cost,voyage time,etc.Then a mathematical model for ship speed optimization based on voyage energy efficiency was established,with the minimization of the voyage EEOI as the objective,which considered main factors that affecting optimal speed such as fuel consumption of main engine,fuel consumption of auxiliary engines,voyage time,etc.On the basis of structural features of the models,algorithm which combined exterior penalty function method and pattern search method was applied to resolve them.In order to further resolve the models in solving practical problems,the VLCC speed optimization application software was designed and developed using programming technology based on Visual Basic combined with Access database.Simple operation and human-computer interaction can be achieved.Optimal speeds of three different optimization targets can be respectively obtained by calculations,according to the inputting initial known data provided by users.Finally,the example of speed optimization of VLCC owned by a shipping company was given out in this paper.The results showed that more daily revenue or more revenue or less EEOI under the voyage generated by the optimal speeds presented in this paper compare with that resulted from the guidance speed given by the shipping company,and proved the software can be applied in practice.It can provide ship managers and operators with assistant decison support,and improve the management and operation of the ship.