某大型原油船脱硫改装电力系统设计

随着MARPOL公约对船舶在全球海域限制SOX排放量的生效日期日益临近,船舶加装脱硫系统已经成为很多船东的选择。文章以某大型原油船加装脱硫系统的改造项目为背景,对改造后电力系统进行分析研究。为满足船东对船舶航行的燃油经济性要求,该项目确定选用增加脱硫发电机并配脱硫系统配电盘的方案。通过对电力系统进行负荷估算、短路电流计算、选择性分析等,得出此方案不仅可行,同时也最大限度保持了原配电系统完整性。     

A connectivity reliability-cost approach for path selection in the maritime transportation of China’s crude oil imports

The focus of this paper is the selection of paths for the maritime transportation of crude oil. In addition to transportation cost, the nodes in a maritime transportation network are always affected by extreme events. Therefore, connectivity reliability must be considered during path selection. In this paper, uncertainty variables are introduced to describe the connectivity reliability of nodes under the influence of extreme events, and an uncertain bi-objective programming model with connectivity reliability maximization and transportation cost minimization as objectives is established for path selection. China’s maritime transportation network for crude oil imports is used as a case study to validate the model, the effects of variations in the model parameters on path selection, transportation cost and connectivity reliability are discussed in the case study. The research results provide a basis on which for government decision makers to better plan crude oil transportation strategies.     

Are AIS-based trade volume estimates reliable? The case of crude oil exports

Most global trade statistics in the public domain refer to official customs data, which are not generally available on a micro (individual cargo) level. With the increasing availability and completeness of ship positioning data from the global Automated Identification System (AIS), it is possible to derive more timely and detailed trade statistics for homogeneous commodity groups. The objective of this article is twofold: (1) to compare the accuracy of AIS-derived trade statistics to official customs data in the crude oil market and (2) to add a breakdown of trade by vessel size over time. We find that while AIS-derived data for seaborne crude exports show good alignment with official export numbers in aggregate, there are substantial temporal and geographical differences across countries and time due to the use of pipelines and transshipment in parts of the supply chain. We highlight the challenges in properly structuring and aggregating micro-level cargo data. Our findings are important for the proper derivation of shipping demand from trade data.     

国外非传统艇型及结构潜艇技术发展 与总体设计思想分析

非传统潜艇具有利于搭载特殊作业任务模块等特点,现在已有越来越多的新型潜艇设计思路被提出。文中较为详细地介绍了国外非传统潜艇技术发展动态,阐述了非传统潜艇在大潜深、浅水水域航行和舷间空间利用方面的独特优势。文中探讨了非传统潜艇的技术特点和发展方向,并分析了非传统潜艇需要解决的关键技术,给出了作者的一些初步结论和见解。     

基于CAESARⅡ的集油管道跨越段应力分析

集油管道跨越段需要考虑的载荷与一般线路段相比较复杂,主要是增加了因风载、雪载、检修活载等引起的位移载荷,以及考虑地震的影响。在姬十联外输管道千井沟跨越段应用了CAESARⅡ软件,分别开展了水压试验应力、持续应力、热胀应力、固定推力支墩约束受力及位移分析及核算,并以ASME B31.3-2012、ASME B31.4-2010作为计算结果的判定依据,实践表明该软件计算结果合理。     

高速公路工程地质与特殊路基设计

以山西高速公路发展过程中对特殊路基的处理,简要论述了公路工程地质在特殊路基勘察、设计过程中所起的重要作用,以供探讨。     

船舶溢油故障树分析与事故案例查询系统开发研究

根据故障树分析理论,基于MATLAB/GUI平台,构建了船舶溢油故障树分析与事故案例查询系统。该系统可实现针对船舶溢油事故发生原因和概率的定性和定量分析、及事故案例的多条件筛选查询功能。利用构建的系统对船舶碰撞导致溢油事故故障树模型进行了最小割集、顶事件概率和底事件重要度的求解分析,结果表明该系统操作简便,计算耗时少,结果准确,可以为船舶溢油事故风险分析提供辅助工具,具有很好的实用价值。     

化子闸泵站机组选型分析

化子闸泵站是姚江二通道(慈江)东排工程的梯级泵站之一,其主要任务是加大姚江干流东排分洪能力,提升江北、镇海片防洪排涝能力。泵站设计流量150 m3/s,设计净扬程仅0.32 m,属大流量超低扬程泵站。从水力性能、工程投资、施工和运行管理等方面综合比较,选用了竖井贯流泵装置,TJ04-ZL-07号水力模型。叶轮直径3.9 m,转速60 r/min,是目前国内最大口径和最低转速的竖井贯流泵装置。水泵结构设计的关键点是水导轴承,要求有较好的承载耐磨能力,并且在特低转速下能够形成油膜。经计算分析表明,选用巴氏合金油润滑轴承可满足安全运行要求。     

旋压皮带轮芯模退料装置的改进

基于对旋压皮带轮旋压成型技术的研究,在退料力分析基础上,对退料装置的结构进行了改进,并采用了退料油缸,解决了旋压皮带轮退料难的问题,提高了该产品的加工质量和生产效率。     

某船主减速齿轮装置电动备用滑油泵启停故障分析

文章以某船主减速齿轮装置电动备用滑油泵启停故障案例为研究对象,通过分析溢流阀工作性能,得出溢流阀内部先导弹簧损坏是此次故障的主要原因.根据故障原因,制定了更换优质进口先导弹簧材料的维修方案,故障排除.