EPC集装箱码头变电所电气设备选型

针对EPC(Engineer,Procure,Construct)即工程总承包(设计,采购,施工)集装箱码头变电所电气设备的设计选型工作,结合孟加拉吉大港新锚地集装箱码头项目变电所电气设备选型的实际案例进行分析、探讨。文中以设备的技术分析为基础,综合考虑经济、设备性能等因素,优化选择设备。最后的选型结果既满足了业主的技术要求,又在成本方面得到了控制。     

超大型集装箱船低压配电系统设计

随着集装箱船的大型化发展,传统的AC220V低压配电网络已不能满足船舶大型化带来的用电需求。针对低压配电系统面临越来越严峻的电压降问题,对超大型集装箱船低压配电系统进行技术和经济性分析,根据超大型集装箱船“双岛”船型布局的特点提出一种分布式低压配电网络架构。对传统式和分布式2种低压配电网络架构进行对比分析,在减小电缆压降、缓解电缆通道拥堵和降低人工成本方面进行计算与分析。经实船验证,分布式低压配电系统能有效解决电压降和电缆通道拥堵等问题。分布式系统是超大型集装箱船低压配电系统设计的一种有效尝试,可为今后超大型集装箱船低压配电系统设计提供参考。     

基于OpenFOAM的全回转推进器非定常性能预估

本文选择某一全回转吊舱推进器为研究对象,运用任意网格面元法(AMI)CFD数值计算方法,计算采用的开源数值计算软件OpenFoam对全回转推进器非定常敞水水动力性能进行了研究分析.控制方程离散采用有限体积法,湍流模型选取SSTκ-ω 模型,速度压力耦合采用PIMPLE算法求解.通过与试验结果比较,验证了基于OpenFoam的非定常数值计算方法在全回转推进器敞水性能预报的可靠性和有效性.     

Weekly container delivery patterns in liner shipping planning models

This paper addresses a fundamental question related to nearly all container liner shipping planning models: whether the implicit assumption of identical container delivery pattern every week is valid in a situation of identical shipping services and identical cargo demand every week. We prove that when the number of containers transported from one port to the next is formulated as a continuous variable, the resulting mathematical model with an identical container delivery pattern is equivalent to the model with general container delivery patterns which can be different in different weeks. When the number of containers transported is formulated as an integer variable, the model with an identical container delivery pattern is not equivalent to the model with general container delivery patterns. However, the difference between the optimal objective values of the two models is negligible for practical applications. In sum, little, if not nothing, is lost by assuming an identical container delivery pattern in liner shipping planning models.     

Socioeconomic factors affecting the job satisfaction levels of self-employed container truck drivers: a case study from Shanghai Port

The job satisfaction level (JSL) of self-employed container truck drivers (SCTDs) is vital to the container trucking industry’s (CTI) stability in China. An anonymous field survey of 645 SCTDs was conducted at Shanghai Port. Three ordered probit models were, respectively, developed to analyze the drivers’ JSLs, their attitudes, and reactions to a CTI downturn. This study contributes to the literature that the demographic variables were not statistically significant for the SCTDs’ current JSLs, while higher income SCTDs with fewer expenses were expected to have higher JSLs. During an industry downturn, drivers with families in Shanghai showed more job dissatisfaction. More working hours, lower income, expensive diesel fuel, a high consumer price index (CPI), and a low freight-to-distance ratio (FDR) significantly lowered the JSLs. An increase in the price of diesel fuel and the CPI, and a lower FDR exposed the industry to risk and instability. Additionally, credible evidence indicated that as the dissatisfaction levels of SCTDs rise in a downturn, SCTDs implement more practical measures that may negatively affect the industry’s stability as well as society’s. Based on these findings, managerial or policy implications were proposed to efficiently improve SCTDs’ JSLs and CTI stability in Shanghai.     

An equilibrium-based network model for international container flows

The liner shipping industry is a highly complex system and is extremely sensitive to rapid changes in the environment. To facilitate decision-making in response to endogenous and exogenous shocks, this research develops a strategic network model based on equilibrium principles to analyze the international marine liner shipping network according to port charge, congestion level at the port, and load factor of the ship and estimates the possible container flows under different scenarios in the long run. The distribution model of container flows is extended from Beckmann's transformation. To calibrate the parameters employed in the model so that it offers greater fidelity in predicting container flows, we devise a descent direction-based heuristic. The proposed framework is empirically applied to various scenarios to validate the model and predict the flow pattern after significant events. By identifying these events’ potential impact on the maritime network, the presented model can help relevant stakeholders reduce uncertainty when shaping maritime policies so that they can seize opportunities to increase their competitiveness and maintain their advantage in the maritime market.     

四卷筒轻型RMG及其在空箱堆场中的应用

根据集装箱堆场空箱堆取作业的特点,提出了一种四卷筒轻型空箱RMG的方案,对其关键技术进行研究。目前该机型已用于空箱堆场作业,其适应性强、性价比高,特别适合于专业空箱堆场和中小码头应用。     

大型集装箱船压载舱溢流保护系统设计和研究

减少船舶自重以增加货运量是现代造船的重要课题之一。对大型集装箱船的压载水和压载舱透气管路进行系统性优化,可以达到船舶减重、节约钢材和节能减排的目的。以某大型集装箱船为例,分别给出了货舱区域和机舱区域两种压载舱溢流保护系统的布置方案,并运用管路阻力公式计算出两种方案下压载水舱的设计载荷,结果显示优化减重效果显著。同时,还列出了两种方案的优缺点,对不适用的船只进行了说明。     

UR-S11A对大型集装箱船结构设计的影响研究

国际船级社协会针对集装箱船的新标准UR-S11A已于2016年7月1日正式生效,其对大型集装箱船结构设计的具体影响值得研究。以一艘13 500 TEU集装箱船为例,首先分析了UR-S11A相比UR-S11和劳氏船级社(LR)规范在强度校核上的差异,然后通过对总纵屈服强度、屈曲强度和极限强度的研究分析了新标准对船体结构的影响。结果表明,UR-S11A对在0.3~0.4船长处船体梁的总纵弯曲和极限强度的要求更高,部分纵舱壁板与外板的剪切和屈曲强度以及双层底桁材纵骨的屈曲强度受新规范影响较大。     

岸边桥式起重机技术新进展

简要介绍了近年来抓斗桥式起重机、岸边集装箱起重机等岸边桥式起重机的主要技术进步,包括差动原理的应用、交流变频调速系统的应用、自动控制技术的应用以及越来越多地采用载重小车和单箱梁结构型式的情况。