A Study On The Planning And Scheduling Optimization Methods Of Polluted Water Disposal Ships For Inland Rivers

With the continuous development of water transportation,the number and tonnage of inland river ships are increasing.The amount of water pollutants to be delivered,such as domestic sewage,oil sewage and household garbage,is increasing day by day.The discharge and improper disposal of ship water pollutants will cause serious harm to the water environment.Therefore,how to accurately measure the amount of ship water pollutants to be delivered and scientifically configure the number of ship water pollutant receiving and disposal vessels(hereinafter referred to as "receiving and disposal vessels")has gradually attracted the attention of management departments.To solve this problem,this study proposed a method to measure the amount of ship water pollutants to be delivered in inland river region based on the data of ship entry and exit and ship Automatic Identification System(AIS).On this basis,the imbalance grade judgment System of ship water pollutant receiving facilities in port region was constructed.A model for determining the allocation of receiving and disposing vessels and its scheduling optimization model are proposed for the unbalanced region.The main work of this paper is as follows:(1)Cleaning and processing of ship’s AIS data in and out of port.The paper introduces the situation of ships entering and leaving ports and the AIS data of ships in the inland river region,puts forward the cleaning and filling scheme of abnormal data,determines the ship type,ship class,ship location and other information based on ship entering and leaving ports data,and determines the space-time distribution of ships in the research area based on ship AIS data.(2)Calculation of ship water pollutants to be delivered and analysis of supply and demand imbalance of receiving facilities.Screen the inbound and outbound data of ships to be delivered in the research area,and determine the track and time of ships to be delivered.Based on the total number of ships(number of crew members,number of passengers),ship class,ship type(passenger ship,cargo ship)and travel time information in the data of ships entering and leaving the port,combined with other factors affecting the amount of water pollutants to be delivered,the amount of domestic sewage,oil sewage and household garbage generated(to be delivered)from ships in the research area is estimated.On this basis,based on Bossel model,the classification system of imbalance between supply and demand of receiving facilities was established with port size,water pollutant delivery demand and factors affecting receiving capacity as indicators,providing reference for regional selection of subsequent optimization dispatching model.(3)Allocation determination and scheduling optimization model of receiving and disposing ship.In view of the region where water pollutant receiving facilities are unbalanced and there is no special dock for water pollutant receiving and disposal,the study area is firstly divided into far and near receiving areas according to the driving distance required for receiving and disposing ships,and the proportion of water pollutant to be delivered in the far and near areas is determined based on the AIS data of ships.In order to minimize the total dispatching cost of the receiving and disposal ship,the receiving capacity and working time of the receiving and disposal ship were taken as constraints to establish the number optimization model of the receiving and disposal ship configuration and solve it with the uncertainty method.On the basis of this model,the optimization model of receiving and disposing ship scheduling is established and solved by genetic algorithm.(4)Case study.Taking an inland water area of the Yangtze River as the case study object,based on the data processing method and optimization model proposed above,the generation of water pollutants from ships in the case area,the estimation of the amount to be delivered,the judgment of the imbalance level of receiving facilities,the determination of the allocation amount of receiving and disposing ships and the scheduling optimization were completed.The results show that the number of ships reached the peak on May 31,2018,with 257.73 tons of domestic sewage,7.65 tons of oil sewage and 4.96 tons of domestic garbage to be delivered.Based on ship AIS data,the number of ship track points in the far and near areas accounted for 37.69% and62.31%,respectively.The evaluation level of imbalance rating system of receiving facilities is level IV,so it is necessary to improve the receiving capacity of regional water pollutants.Using the established optimization model,it is suggested to configure5-7 large receiving and disposal vessels and 10-14 small receiving and disposal vessels.Under the maximum capacity of receiving water pollutants,the dispatching cost of receiving and disposing ship in a single day is 40,900-57,200 yuan.Further,according to different service mode of receiving treatment of ship to carry out the contrast analysis,when only consider scheduling costs,this study proposed the fairness of the priority service mode and first come first service,large amount of water pollutants to required dispatch cost,service,service mode to the nearest comparative circuit receives the service mode on the specified path scheduling average cost decreased by 26.39%.When only the fairness of receiving and disposing ship service is considered,the fairness priority service model proposed in this study is superior to other service models.To sum up,the receiving and disposing ship service mode that considers the fairness of the service ship proposed in the study is one of the optimal scheduling schemes that comprehensively considers the dispatching cost and service fairness of the receiving and disposing ship.The above model method and case study provide a feasible way to protect the water environment,improve the efficiency of receiving water pollutants from ships and reduce the cost of receiving water pollutants.