Research On The Scheme Of Low-Frequency Entire Train At The Loading Area Considering Inventory Theory

With the large-scale construction of the railway and the continuous improvement of the capacity at the loading and unloading area,the loading area can undertake more freight loading operations and form more kinds of direct trains.In recent years,the gradual improvement of the railway network has promoted the development of the theory and technology of the optimization of the organization of the train flow in the railway loading area,and it is possible for the freight owners with smaller planned daily traffic flow to collect the whole train running low frequency direct trains.Therefore,when optimizing the traffic flow organization at the loading area,the railway transport enterprises should not only consider the railway transportation cost,but also consider the impact of different traffic flow organization forms on the inventory cost of customer.By comprehensively considering the costs of both sides,the research on the optimization of low-frequency entire train at the loading area is carried out.Based on the consideration of customer inventory costs,this article explores the possibility of low-frequency entire trains,and establishes an organic unity between the transportation costs of railway enterprises and the inventory costs of customers in the process of transportation service organization.The optimization model of the low-frequency entire train scheme is determined based on the analyzing of inventory cost and transportation consumption,and the effectiveness of the model is verified by optimizing the actual case.The main research contents of this paper include:(1)The concept of "low-frequency entire train" is proposed.Through the introduction and review of the principle of entire train at loading area,the possibility of low-frequency entire train operation is analyzed,and the significance of its operation is expounded.A detailed analysis of the transportation consumption in the traffic organization at the loading area is carried out,which leads to the introduction of the optimization model of the typical organization mode of entire train at the loading area,and the construction process of combining the inventory cost and the typical model is given.(2)The analysis of the change of customer’s inventory cost under different arrival states is given.By quantifying the consumption of the railway transport enterprise and the inventory costs of customers in transit,the operating conditions of a single train flow and low-frequency entire trains under multi-suppliers are explained separately,and two inventory calculation methods under the extreme equilibrium state of arrival are given.And then determined the method of calculating the inventory cost of the receiver in a nonequilibrium state.(3)A comprehensive optimization model of low-frequency entire train at loading area considering inventory cost is constructed.The railway transportation consumption and customer inventory cost under different train flow organization modes are analyzed in detail.The sum of transportation consumption and inventory cost is used as the objective function,and the constraints of equipment,capability,revenue are considered,respectively,to build a state of equilibrium-Ⅰ,equilibrium-Ⅱ and nonequilibrium state of low-frequency entire train comprehensive optimization model.(4)The validity of the model is verified by a practical case.Based on the main flow of coal transportation in our country,Lingshan Station and Beitai Station are selected as the unloading stations of the road network.There are 5 loading stations with cargo demand were identified and unloading area,which are Xiaoxi Station,Xiaonan Station,Gujiao Station,Wuhai West Station and Pingding Station.By solving the models under different equilibrium states,two optimized traffic flow organization schemes are determined,and the results of the two schemes are further analyzed.The comparison and analysis of the reasons for the difference have verified the effectiveness of the model.