Study On Optimization Of Loaded And Empty Train Cooperative Organization Of Coal Transportation Heavy Haul Railway Considering Energy Consumption

Coal transportation railway plays an important role in the layout of China's energy transportation.With the adjustment of national energy structure,the transportation organization goal of the coal transportation heavy-haul railway has changed from“potential mining and capacity enlargement” to “quality improvement and efficiency increase”.The optimization of the transportation organization plan for loaded trains and empty trains considering the condition of energy consumption has become the focus question in the railway industry.Therefore,through field investigation and data mining,this study analyzes the relationship between energy consumption of coal transportation heavy-haul railway lines and the proportion of large trains(10,000 t or 20,000t)and small trains(5,000t),the utilization of line transportation capacity,etc.,and a in-depth research on the transportation organization of heavy-haul coal railway lines considering energy consumption is made:1.Safety protection data from LKJ(Train Operation Control and Monitor Device)is used to gain train speed,distance,time and running states,and a time series data structure is formed accordingly with horizontal and vertical section data,which could provide a data basis for train operation detection.According to the train wind pressure,engine rotational speed and other parameters in the train LKJ data,the train operation state is analyzed and the train operation condition is detected.In addition,the Kalman filtering technique is used to conduct in-depth analysis of the noise data in the operating condition section.Work-energy theorem is used to design energy consumption calculation methods under different traction conditions.Through data fitting technology,a high-dimensional coal transportation heavy-haul railway energy consumption standards table based on Gaussian distribution is obtained.Through case data mining and analysis,the relationship between capacity utilization decision variables and energy consumption is obtained: large trains consume more energy in the sections with small distance or large slope;compressing the departure intervals of large trains may cause the increase of energy consumption.2.On the basis of analyzing and summarizing the differences of transportation organization characteristics between coal transportation heavy-haul railway lines and ordinary railway lines,the characteristics of coal transport corridors to organize vehicle flow based on "trains" are used to transform the transportation organization process into a network flow problem based on time and space networks.Considering the constraints of section carrying capacity,station loading and unloading capacity,assembling and disassembling capacity and the connection time of different trains in the combined station operation,the energy consumption of train traction and shunting process is taken as the important sub-term of the objective function to build the model and algorithm.A series of analytical results are obtained by designing an algorithm to optimize different goaloriented loaded train transportation organization schemes.The results reveal the mutual constraints and dependencies among energy consumption,the ratio of large and small train as well as transportation time occupancy factors,they indirectly reflect the relationship between energy consumption,train structure and capacity utilization,and verify the empirical understanding in railroad operation practice.And besides that,they further promote the transformation of empirical knowledge into theoretical results,and lay the foundation for the subsequent collaborative optimization of loaded trains and empty trains.3.Using the loaded train scheme as input,the problem of empty train transportation organization under the influence of energy consumption factors for a given loaded train transportation organization scheme is studied,and the phased preparation of the loaded train and empty train scheme is realized.Further considering the limitation of the succession of empty train scheme under the given heavy-haul train scheme,on the basis of obtaining the service train chain of each OD stream,the constraints related to the time of trains at the departure or arrival stations are added(e.g.,the time adjustment of the first and last trains serving the same OD stream should be the same)to construct the empty train optimization model under the adjustable arrival and departure time of loaded trains.The design example optimizes the empty train transportation organization scheme under different energy consumption structures and different covariates,and analyzes the change of the empty train scheme index after the adjustment of the loaded train time,revealing the action law between the energy consumption parameters,train operation structure and the number of rail cars.4.Considering the relationship between empty trains and loaded trains,two transportation organization problems are studied,such as the cooperative transportation organization of loaded and empty trains under the influence of energy consumption factors in the scenario of capacity surplus(fixed demand)and in the scenario of capacity constraint(elastic demand).In view of the specific characteristics of the problems,the transport organization optimization models under the two scenarios are established based on the network flow theory,taking into account the spatial and temporal succession of loaded and empty trains,the influence of the empty train supply scheme on the distance,time and energy consumption costs,etc.The adaptive genetic algorithm is designed,solved and analyzed.The results of collaborative optimization of transport organization of loaded and empty trains under fixed demand with different energy consumption parameters are analyzed to reveal the influence of energy consumption parameter structure on train operation structure and railroad rolling stock resources.The calculation case is constructed to analyze the results of the cooperative optimization of transport organization of loaded and empty trains under elastic demand,which reveals the effect of energy consumption parameters on the structure of train operation,the number of rail cars and the transport capacity.5.This research takes Baoshen Line,Xinzhun Line,Shenshuo Line,Zhundong Line and Zhunchi Line as the case network to sort out the loading and unloading capacity,combined decomposition station capacity and section carrying capacity of different types of stations on each line.On this basis,taking the existing freight demand data as the known demand,the organization optimization models of heavy and empty trains collaborative transportation based on fixed demand and elastic demand are established respectively,and the adaptive genetic algorithm is used to solve the model.The obtained optimization scheme is compared with the actual scheme in terms of energy consumption,transportation cost and the cost of “train connecting time” of loaded and empty trains,which is to further verify the feasibility of the proposed model and the effectiveness of the designed algorithm.