Carbon dioxide emissions from port container distribution: Spatial characteristics and driving factors

Port carbon dioxide (CO₂) emissions in China have become an ever-increasing public concern due to their significant impacts on human health and the environment. However, existing studies focus mainly on CO₂ emissions from vessels calling at the ports and cargo handling within the ports, paying little attention to the inland distribution networks. To fill this gap, this paper proposes an easily implemented method for calculating CO₂ emissions from port container distribution (PCD) and investigates their spatial characteristics and driving factors. By analyzing 30 container ports in China, the main findings are as follows. First, road transportation is the major contributor of CO₂ emissions from PCD due to the lack of rail and inland water transportation. Second, PCD carbon emissions exhibit significant local spatial clustering. That is, ports with similar geographical locations tend to present a similar pattern of PCD carbon emissions. Third, as suggested by the spatial Durbin model, PCD carbon emissions are negatively determined by local gross domestic product, number of port berths, but are positively determined by local tertiary industry value and highway freight volume, and waterway freight volume in both local and neighboring ports. These results provide empirical insights into cross-port collaboration in reducing PCD carbon emissions.     

Profit-based maritime container assignment models for liner shipping networks

We propose the problem of profit-based container assignment (P-CA), in which the container shipment demand is dependent on the freight rate, similar to the “elastic demand” in the literature on urban transportation networks. The problem involves determining the optimal freight rates, the number of containers to transport and how to transport the containers in a liner shipping network to maximize the total profit. We first consider a tactical-level P-CA with known demand functions that are estimated based on historical data and formulate it as a nonlinear optimization model. The tactical-level P-CA can be used for evaluating and improving the container liner shipping network. We then address the operational-level P-CA with unknown demand functions, which aims to design a mechanism that adjusts the freight rates to maximize the profit. A theoretically convergent trial-and-error approach, and a practical trial-and-error approach, are developed. A numerical example is reported to illustrate the application of the models and approaches.     

基于CFD的某型满足IRCC-SP符号冷藏集装箱船货舱通风数值模拟

摘 要：以某型满足ABS船级社IRCC-SP符号冷藏集装箱船的货舱通风系统为研究对象，本文采用计算流体动力学CFD方法对通风系统的风机前端进风段和风机后端风管段分别进行数值模拟和流场分析。根据计算结果优化进风段的设计以降低进风阻力，并调整风管结构以满足IRCC-SP符号的风量要求。基于CFD方法设计的货舱通风系统顺利通过了IRCC-SP模型试验，模拟结果与试验数据吻合良好。研究表明，运用CFD方法进行通风系统分析，可以清晰地了解流场分布、通风阻力和风量分配等信息，以此评估通风方案的优劣，并指导优化设计提供。     

Experimental and numerical investigation of lashing bridge and container stack dynamics using a scaled model test

Previously reported container losses were generally attributed to extremely violent motions of containerships due to adverse weather conditions. However, most existing specifications or standards adopted for containers and lashing equipment meet the requirement of static conditions. Hence, further researches on safer container shipping under heavy sea states are required. Consequently, an experimental study method is proposed to measure the dynamic response of 1/10 scaled lashing bridge and container stack. The scaled model of the lashing bridge is constructed based on the similarity theory. Based on two dimensionless numbers, Froude's number and Cauchy's number, eleven container scaled models are employed. A series of experiments with controlled parameters are performed using a three-degrees shaking table (roll, pitch, heave) to present sufficient data to verify the effectiveness of the numerical model. The results of experiments, numerical simulations and calculations of the VERISTAR procedure (developed according to the BV rule) are compared. This study aimed to explore the mechanical behavior of the lashing bridge and container stack under predetermined driving excitations (roll and pitch) which simulated heavy sea states. According to the results, the model can predict conditions similar to real situations of the lashing bridge and container stacks while storages on the weather deck.     

Comparative evaluation of resource cycle strategies on operating and environmental impact in container terminals

This paper examines the use of single and dual cycle operations for three types of resources, namely, quay cranes, vehicles, and yard cranes to improve the operating efficiency and reduce the energy consumption in a container terminal. Various cycle strategies are proposed and their corresponding estimation models, describing the stowage distributions of outbound and inbound containers on a ship and the storage sharing level of blocks in the yard, are formulated to estimate the total number of cycles for the resources. Statistical analyses are conducted to evaluate and compare the effect of different cycle strategies on the cycle reductions. From the experiment results, it was found that collaboration between resources with the single cycle operation always outperforms that under the dual cycle operation without collaboration.     

基于GRNN神经网络的长江干线港口集装箱吞吐量预测

在长江集装箱货源市场调查分析的基础上,根据长江干线集装箱发展形势,结合长江干线港口发展情况及历年数据调查,考虑影响港口吞吐量预测的复杂因素,运用GRNN神经网络的优点,构建预测模型。预测结果证明,该模型在应用中是有效的,且当样本数据短缺时,预测效果也较佳。     

铁路冷藏集装箱运输作业过程控制研究

概述我国铁路冷藏运输发展现状,通过比较铁路冷藏集装箱与普通集装箱运输作业过程的差异,划分作业时间,研究铁路冷藏集装箱试运的相关数据,分析铁路冷藏集装箱试运作业过程.从各环节基本操作时间和各环节之间的等待时间两个方面,对铁路冷藏集装箱作业时效性的影响因素进行分析.提出加强相关政策与制度的落实,控制作业环节时间,逐步建立并完善铁路冷藏集装箱运输服务信息系统等加强铁路冷藏集装箱作业过程控制的措施与建议.     

铁路集装箱起重机异步电动机调压节能的优化方法

铁路集装箱起重机异步电动机具有恒转矩运行和变工况负载的特性,基于异步电动机T型和Γ型等效电路,将定子的铜耗和铁耗看作是仅与定子电压有关的不变损耗,将转子的铜耗看作随负载转矩变化的可变损耗,推导出异步电动机电气总损耗计算式和最优调节电压计算式,并通过实例进行验证。研究结果表明:当转差率为0.01～0.03、起重机电机稳定运行时,按照近似转差率计算的起重机负载转矩误差不超过1.8N.m;在起重机的工作电压高于220V时,电气总损耗的计算误差几乎为零;最优调节电压及其误差随着起重机负载转矩的增加而增大,但在起重机的工作电压范围之内,最优调节电压误差不超过7V;电动机按照起重机负载转矩的变化适时调压时,其电气总损耗小于380和220V恒压驱动的电气总损耗,尤其是在起重机空载运行时,具有显著的节能效果。     

集装箱站装卸线不挂网列车牵引供电设计创新

针对电气化铁路集装箱站装卸线采用不悬挂接触网运输方式,结合目前集装箱站设置方案,研究集装箱装卸线两端接触网行车可能的安装方式,对牵引供电系统的接触网悬挂及下锚安装进行分析,为实现列车牵引供电—接触网在集装箱站装卸线范围内不悬挂接触网行车,设计出两种有针对性的接触网终锚结构方式,满足了列车进出集装箱站装卸线的牵引供电需要。     

T_7型轨道衡检衡车起重小车的使用和维护

针对当前广泛使用的T7型轨道衡检衡车,介绍其起重小车的结构组成、电器控制系统工作原理和安全保护措施、操纵注意事项、重点维护保养方法,为确保检衡车状态良好、运行可靠提供理论依据,为检衡车操作人员提供参考。