Research On Nonlinear Key Problems Of Design And Operation Optimization Of Refined Oil Supply Chain

At present,refined oil occupies a relatively high proportion in China’s energy structure.With the gradual increase of energy demand,the scale of the refined oil supply chain system also expands.The construction and management of a safe and efficient refined oil supply chain system is of great significance to promote the construction of China’s energy network and improve the economic efficiency of enterprises.Refined oil supply chain refers to the network chain organization constructed by upstream,midstream and downstream enterprises which is in order to deliver refined oil to users.The design and operation optimization of refined oil supply chain is a very complex large-scale nonlinear system problem,which greatly increases the difficulty of establishing and solving the mathematical model of refined oil supply chain.In addition,optimization of refined oil supply chain includes optimization of supply chain construction and refined oil primary logistics at the strategic level,optimization of refined oil pipeline scheduling and oil pump operation at the tactical level,etc.The time range varies from months/years to seconds/minutes,which leads to completely different nature of decision-making.During the entire optimization process,different types of models need to be solved collaboratively.This paper will study the above-mentioned key issues of design and operation optimization of refined oil supply chain.Firstly,considering transportation mode and cost of refined oil,refinery construction restrictions and other constraints,a mathematical model of continuous refinery location was established with the goal of achieving the highest economic benefit.A bi-level decomposition algorithm was proposed to solve the model.The global optimal solution of refinery construction plan,pipeline construction plan and refined oil transportation plan can be obtained more efficiently,which can reduce the construction cost of refined oil supply chain and improve the operation efficiency.After determining the main body of refined oil supply chain,considering the pipeline sequential transportation,highway and railway point-to-point transportation,a multimodal transportation collaboration optimization model of refined oil logistics was established.The model also considered factors such as the capacity and cost of different transportation modes.Rough scheduling was adopted to improve the efficiency of model solving,ensure the feasibility of obtained transportation plan and storage plan,and improve the economic benefits of refined oil sales enterprises.Based on the supply and demand plan of pipeline determined by refined oil logistics,with the goal of minimizing the deviation of stations delivering refined oil,a batch scheduling optimization model of refined oil pipeline expressed in continuous time was established.The model considered batch tracking constraints,stations delivering constraints,pipeline transportation constraints,etc.The idea of partial order linear expansion was introduced into the time node sorting of refined oil scheduling,which reduced the number of critical binary variables.Batch scheduling plan of pipeline that conforms to the field operation process could be obtained with higher efficiency of model solving.For the situation of using fixed-frequency pumps on site,it is necessary to determine the pump operation plan while determining the batch scheduling plan for refined oil pipeline,so as to ensure the execution of batch scheduling plan.Batch scheduling optimization model established based on continuous time expression was associated with pump operation optimization model established based on discrete time expression through time nodes.A rolling solution method was proposed to improve the solution efficiency and ensure that the batch scheduling plan and the pump operation plan meet the field operation requirements.