基于碳排放最小化的公铁两网之间大宗货流转移及调控机理

It has been an essential national strategy to reduce the carbon emissions in the traffic and transportation field. According to our pre-analysis, the freight turnover of highway was 1.76 times as much as that of railway in 2011, but the former energy consumption was 7.08 times more than the latter's. As the result, as long as 10% of the road freight diverted into railway from highway, there should be more than 23 million tons carbon emissions reduced. However, mass freight diversion involves flow assignment of complex network, which contains thousands of stations and hundreds of thousands of OD pairs. Therefore, it remains a scientific puzzle to be solved urgently to divert mass freight flow, which is different in volume, distance and regional features, from highway to railway and draw up the best utilization scheme of railway transportation capacity. Using the coefficient removal method, we are intended to calculate the capacity released by the typical main lines of existing railway when the High-Speed railway network established in the future. We also apply the multi-objective combinatorial optimization method to construct an iteration model of freight flow diversion between highway and railway networks based on carbon emissions minimization, further, identify the infeasible diverted freight flow and potential diversion scale with the method of loading virtual arcs. The model test is conducted under the background of the typical channels in the West-East Coal Transfer plan, in which we focus our analysis on the coal flow where the average haul is more than 800 kilometers. Based on the analysis, we go on to complete the empirical study and hopefully provide a theoretical foundation on a technical and policy level for the reduction of carbon emissions in the land transportation field.

减少交通运输领域的碳排放已经成为国家的重要战略目标。根据我们的前期分析，2011年我国公路货运周转量是铁路的1.76倍，总能耗是铁路的8.08倍，若将10%的公路周转量转移到铁路，可减少碳排放量2300多万吨。由于公铁两网之间流量转移涉及到数千个车站及数十万股OD的复杂网络配流，故将不同运距、运量和区域特性的大宗货流由公路转移到铁路并形成最佳的铁路运能利用方案是一个亟待解决的科学难题。本项目拟采用扣除系数法对高速铁路初步成网后既有铁路部分典型干线货运能力的释放程度进行测算，采用多目标组合优化方法构建基于碳排放最小化的公铁两网之间流量转移迭代模型，并通过加载虚拟弧方法识别转移的不可行流和潜在的转移规模。项目拟以我国典型西煤东运通道为背景，着重分析运程在800公里以上的煤炭流从公路转移到铁路的模型检验，完成实证研究，为减少陆路运输领域碳排放提供技术政策层面的理论支撑。

大宗货流在公路和铁路两网之间的转移与合理调控本质上就是流量在运输网络上的分配问题，基于减少陆路运输碳排放，本项目就公铁两网货流转移问题完成了以下研究：. 1) 分析了高铁初步成网后部分既有典型铁路通道货运密度特征、高铁成网后对既有铁路运输通道货运能力的影响机理，研究了基于扣除系数的典型干线货运能力释放测算理论。. 2) 研究了影响公铁两网之间大宗货流转移的关键因素，包括公路大宗货流转移到铁路涉及到的吨公里费率、端点集疏费用、中转滞留的物流成本增加、隐现的碳排放变化折合费用、部分公路的拥堵成本等。. 3) 分析了流量转移对铁路直通流区段的能力损失放大效应及消除方法，并研究了基于碳排放和中转费用等综合成本的公路大宗长程货流部分运程转移至铁路的公铁衔接运输模式。. 4) 分析了铁路大宗直达货物运输的优势特征与运量转移条件，研究了大宗货流从公路转移到铁路的调控机理。对于能力富余的铁路通道，提出了降低铁路通道阻抗、适度增加繁忙公路通道阻抗的方法；针对远离高铁的能力紧张既有线，提出了部分铁路车流向远离最短路的非繁忙次短路通道转移的方法。包括大区域迂回运输理论，以合理的绕道率为代价，腾出部分铁路最短径路运输量以最大化吸纳公路大宗长程货流，确保整体运输流碳排放的最小化。. 5) 构建了基于碳排放最小化的公铁两网之间流量转移迭代模型，包括区域路网层面铁路货流调整的0-1背包模型，并讨论了公铁两网之间大宗货流的最佳转移量和最佳转移地点问题。. 6) 研究了陆路运输碳排放和社会物流成本系统目标权衡最小化下的大宗货运主导型铁路网络规划模型和运力资源优化配置方法。. 7) 以中国部分西煤东运大通道为背景进行了实证研究，为减少陆路运输领域碳排放提供技术政策层面的理论支撑。