Research On Ship Fuel Consumption Prediction And Energy Efficiency Improvement

As the main mode of transportation in international trade,maritime transportation is crucial to the prosperity of international trade and the development of the global economy;at the same time,maritime transportation is also the main mode of transportation in our foreign trade,and is the basic support and important guarantee for promoting the development of our export-oriented economy and the construction of "Belt and Road Initiative".Although maritime transport is the most energy-saving transport mode,shipping is still one of the industries with the highest greenhouse gas(GHG)emissions.In order to effectively reduce GHG emissions from shipping,the International Maritime Organization has introduced a series of regulations on ship emissions reduction,and also put forward specific emission reduction targets.Our government also attaches great importance to GHG emission reduction in the shipping industry,and has introduced a corresponding work program and put forward clear emission reduction targets.The introduction of these emission reduction regulations and programs and the proposed emission reduction targets have brought enormous pressure on the shipping industry to reduce GHG emissions.On the other hand,the rising fuel prices in recent years have significantly increased the operating costs of ships,thus bringing pressure on the shipping industry to reduce costs.Facing the double pressure from emission reduction and cost reduction,the shipping industry urgently needs to improve the energy efficiency of ships to reduce the GHG emissions of ships and reduce the operating costs of ships while maintaining the output.Compared with energy efficiency improvement methods at the design stage,energy efficiency improvement methods at the operation stage are applicable to both new and existing ships,and have the advantages of low investment,significant effect and easy implementation,which are therefore favored by the shipping industry.The prerequisite for implementing the energy efficiency improvement method in the operation phase of a ship is to accurately predict the fuel consumption of a ship under different sailing conditions.Therefore,it is of great theoretical and practical significance to carry out research on ship fuel consumption prediction modeling and further study how to improve the existing ship energy efficiency improvement methods based on the constructed fuel consumption prediction model to promote energy saving,emission reduction and sustainable development of the shipping industry.In view of this,this thesis conducts an in-depth study on the two closely related and interdependent scientific issues of ship fuel consumption prediction and energy efficiency improvement,and the main research contents are as follows.(1)Based on the general analysis logic of "concept definition-theoretical foundation-operation mechanism-framework construction",the important concepts involved in this study are defined,the theoretical foundation of this study is elaborated,the relationship between ship fuel consumption prediction and energy efficiency improvement is explained,and the theoretical framework for the study of ship fuel consumption prediction and energy efficiency improvement is constructed on the basis of the above study.(2)With the purpose of identifying the main influencing factors of ship fuel consumption,the generation mechanism of ship fuel consumption is firstly analyzed,then the influencing factors of ship fuel consumption are comprehensively analyzed based on the generation mechanism of ship fuel consumption,and finally the main influencing factors of ship fuel consumption are identified in combination with the actual needs of the shipping industry,thus providing a theoretical basis for the construction of the ship fuel consumption prediction model.(3)After identifying the main influencing factors of ship fuel consumption,how to construct a ship fuel consumption prediction model is further studied.Firstly,the advantages and disadvantages of three system modeling methods,namely,white-box,black-box and grey-box,are compared and analyzed,and the reasons for choosing the grey-box modeling method are explained in the light of the actual demand of ship fuel consumption prediction.Secondly,the logical framework of grey-box modeling for ship fuel consumption prediction is designed based on the steps of grey-box modeling.Then,the three issues of model structure construction,parameter estimation,and model analysis and evaluation are studied in depth in turn based on the logical framework of modeling.Finally,a grey-box model for ship fuel consumption prediction is constructed that considers still water resistance,the influence of wind,waves and ocean currents,and the added resistance due to changes in hull and propeller conditions,which provides a model basis for the study of ship energy efficiency improvement methods.(4)Based on the grey-box model for ship fuel consumption prediction constructed in this thesis,how to adopt certain methods to improve the energy efficiency of ships is further studied.Firstly,the energy efficiency improvement methods in the operation stage of ships are comprehensively analyzed;then,two methods,namely,speed optimization and weather routing,are selected from these methods for in-depth study,taking into account the energy saving effect and required investment.Specifically,based on the grey-box model for ship fuel consumption prediction constructed in this thesis,a ship speed optimization model considering the influence of ocean currents and an improved ship weather routing model at variable speed are constructed and the corresponding solution algorithms are designed,so as to improve and perfect the two methods of ship energy efficiency improvement,namely,speed optimization and weather routing.(5)The grey-box model for ship fuel consumption prediction and the two proposed ship energy efficiency improvement methods(i.e.,ship speed optimization considering the influence of ocean currents and improved ship weather routing at variable speed)are analyzed in the case to verify their accuracy and effectiveness;based on the results of the case study,six feasible countermeasures for ship energy efficiency improvement are proposed,which provide a reference for energy saving,emission reduction and sustainable development of shipping industry.The theoretical contributions of this thesis are mainly reflected in the following four aspects:(1)the theoretical framework for the study of ship fuel consumption prediction and energy efficiency improvement is constructed,which enriches and improves the theoretical system of ship energy saving and emission reduction;(2)the main influencing factors of ship fuel consumption are identified,which provides the theoretical basis for the construction of ship fuel consumption prediction model and also expands the identification methods of main influencing factors of ship fuel consumption to a certain extent;(3)a grey-box model for ship fuel consumption prediction that simultaneously considers still water resistance,the influence of wind,waves and ocean currents,and the added resistance due to changes in hull and propeller conditions is constructed,which makes up for the shortcomings of the existing related research;(4)two ship energy efficiency improvement methods,namely,speed optimization and weather routing,are improved and perfected,which makes up for the shortcomings of the existing related research.At the same time,this thesis also has important practical value,that is,the research results of this thesis in ship fuel consumption prediction model,ship energy efficiency improvement method and ship energy efficiency improvement countermeasures can provide model basis,method support and decision reference for energy saving,emission reduction and sustainable development of shipping industry.Thus,the development of this study has important theoretical and practical significance for promoting energy conservation,emission reduction and sustainable development of the shipping industry.