Research On Hybrid Algorithm Of Coal Supply Chain Equipment Maintenance Scheduling Based On Dynamic Network Flow

The regular maintenance of coal handling equipment is the key to ensure the normal operation of the equipment and the smooth delivery of coal.In order to ensure the stability of coal supply chain,regular preventive and corrective maintenance are to be carried out for the supply chain facilities such as railway,port equipment and coal production equipment every year.However,the impact of system capacity reduction caused by these maintenance outages is overwhelming.Under the idea of supply chain management,the maintenance of all equipment must be considered as a whole,planned coordinately,to ensure the shortest total outage time of a system,maximizing the capacity of the throughput of the system.On the basis of the existing research,this dissertation focuses on the study of the dynamic network flow problems with outages on arcs,which can describe the maintenance of coal handling equipment.Given a network with a source node and a sink node,we consider the problem of scheduling a set of jobs on the arcs of a network,and the maintance results in an outage.The jobs on the arcs must be finished during the time-window.Once the job gets started,the arc,corresponding to the job,is unavailable;therefore the timing of jobs should be coordinated so that the total flow over the planning time horizon is maximized.This problem is a novel combination problem that is proved strongly NP-hard.A tabu search-based heuristic method is designed to integrate exact integer linear programming,forming a hybrid algorithm to conduct theoretical research.The experimental data show that the hybrid algorithm performs better in large-scale network scenarios.The main research work and innovation are as follows.(1)In view of the present situation of equipment maintenance in the coal supply chain network,this dissertation analyzes the influence of the periodic arrangement of equipment maintenance on the total throughput of the network,and expounds the importance of equipment maintenance scheduling;theoretically analyzes the correlation between equipment maintenance scheduling problem and dynamic network flow in coal supply chain,and uses "the dynamic network flow problems with outages on arcs" to model the problem.(2)Mainly analyzes the characteristics of "dynamic network flow problems with outages on arcs" model,and designs a hybrid algorithm of which a Tabu search algorithm is the main body,which is mixed with primal and dual information from the linear programming to speed up the search process;and elaborates the design process of the hybrid algorithm.(3)Conducts experiments based on standard examples;uses Python language programming and calls the Gurobi solver to verify the effectiveness of the algorithm.The results show that the presented hybrid algorithm performs well in every example group,and it is even excellent in the large-scale network scenarios.