Z6170ZLC型LNG-柴油双燃料船用增压发动机性能仿真分析

LNG-柴油双燃料发动机同时存在预混合燃烧和缸内压缩点火燃烧,其性能与原型柴油机有较大的差别.文中基于AVL-Boost发动机性能仿真软件,采用等热值当量处理不同比例的混合燃料,考虑了不同工况预混合LNG燃料对充气效率的影响,采用双韦伯函数燃烧放热率模拟不同比例混合燃料的预混合燃烧和缸内压缩点火燃烧,对比分析了LNG-柴油双燃料增压发动机和原型柴油机的动力性和经济性.研究表明：（1）预混合LNG燃料对充气效率的影响不会导致单点预混合LNG-柴油双燃料增压发动机的动力性下降;（2）相比较原型柴油机,各负荷工况双燃料发动机的燃油经济性均有下降,低负荷工况燃油经济性下降更为严重;（3）高负荷工况掺烧过高比例的LNG燃料将导致气缸压力急剧增加.     

LNG船机舱内通风气流组织的数值分析

运用CFD技术手段,对LNG船机舱内通风气流组织进行数值分析,消除通风死角产生的安全隐患。针对风管与舱室形成的计算域形状复杂的问题,机舱通风流场被分解为风管与舱室两个计算域,通过设置通风格栅的边界条件实现数据传递。采用K-ε湍流模型模拟舱室内通风气流,分析表明机舱内设备与管路对通风效果有明显影响,设备间的空挡存在通风死角。研究表明CFD技术是船舶通风设计优化的良好工具。     

浙江LNG码头总平面布置试验研究

浙江LNG码头是我国目前最大的LNG码头之一,所处环境相对复杂,在项目设计过程中,为确定合理的码头总 平面布置方案、保证船舶安全系靠泊,采用了物理模型试验的方法,对3个不同的平面布置方案进行了比较,通过试验得出 不同方案下的船舶运动量及系缆力等参数,通过分析试验结果最终明确了合理的总平面布置方案。     

小型LNG船舶内河航行可行性探讨

介绍海港LNG船舶航行实行交通管制的原因,对比分析了LNG船舶与LPG船舶的危险性。结合我国内河液体散货运输船舶航行管理现状,对小型LNG船舶在内河航行的可能风险及应对措施进行探讨,认为采用双壳双底结构的小型LNG船舶在我国内河正常航行是可行的,不需要采取特殊的交通管制措施。     

LNG运输船液货围护系统次层绝缘箱质量跟踪系统

次层绝缘箱是液化天然气（Liquefied Natural Gas,LNG）运输船液货围护系统的重要组成部分。阐述次层绝缘箱的箱体组装、胶条测试和质量风险,提出基于专用的环氧树脂涂胶流水线的次层绝缘箱质量跟踪系统,为LNG运输船液货围护系统提供安全保障。     

营口港仙人岛港区LNG码头选址规划方案

仙人岛港区是环渤海地区重要的大型综合性港区,属于双堤环抱空间格局,规划大型泊位多,船舶流量密集。LNG码头具有一定的特殊性和排他性。针对在环抱式港池内LNG码头选址和规划存在的问题,以仙人岛港区为例,集成利用多项模型技术研究通航安全、通航影响、陆域安全、泊位布置和空间利用等,提出LNG码头选址、码头泊位及水域布置方案,对仙人岛港区建设LNG码头起到了关键技术支撑。     

BOG处理工艺在液化天然气接收站中的应用

LNG接收站运行期间会产生蒸发气（BOG）,使储罐压力处于不稳定状态,因此要对BOG进行处理。BOG处理工艺分为直接输出工艺和再冷凝工艺,由于再冷凝工艺能耗小、先进、合理,因此应用广泛。文中介绍了LNG接收站再冷凝工艺的工艺流程,其要点是采用BOG压缩机负荷调节、再冷凝器高压补气和调节气液比的方法来实现再冷凝器的液位控制,并使储罐压力和BOG处理系统都达到稳定状态。     

Evaluation of consequence assessment methods for pool fires on water involving large spills from liquefied natural gas carriers

This article concerns thermal radiation hazards associated with unconfined liquefied natural gas (LNG) spills on water. Consequence assessment methods were compared to clarify their model characteristics in large-scale LNG spills from an LNG carrier (LNGC). The consequences of LNG release, pool spread, and pool fire hazards were estimated using the following practical methods: the Federal Energy Regulatory Commission’s (FERC) method, the Sandia National Laboratories’ method, and the Fay method. The sensitivity of consequence analysis results to the breach size of a tank was examined under the assumption that LNG is released from a common type LNGC of 125000 m³ cargo capacity. Consequently, it was found that the FERC method is useful from the practical viewpoint of being applicable to any breach size. Finally, thermal radiation hazards from pool fires involving spills from one of the latest and largest LNGCs (250 000 m³ cargo capacity), which are currently considered for construction, were investigated using the recommended FERC method, and the results are discussed in comparison with those for common type LNGCs. As a result, it was found that the maximum thermal hazard distance is longer by only about 24% compared with the common type LNGC, whereas the spill volume is twice as much.     

A method to measure the eco-efficiency of diesel locomotive

Brazilian railroads transport over 490 million tons a year using diesel-electric locomotives. These locomotives emit several pollutants into the atmosphere and because of that, the railroads seek to reduce emissions and achieve global emission standards. Thus, it is important to analyze the environmental impact of the use of diesel and alternative fuels to reach environmental standards. This paper makes use of a method based upon the World Business Council for Sustainable Development (WBCSD) metrics to evaluate the locomotives’ eco-efficiency. The method was applied to Estrada de Ferro Vitória a Minas (EFVM). Different scenarios representing the exchange of fuel sources and technologies were developed, tested and analyzed. The impacts were evaluated by seven eco-efficiency performance indicators and compared with United States Environmental Protection Agency (EPA) standards. The results offered cost savings and emissions reduction opportunities.     

液化天然气运输船系泊绳缆

首先介绍液化天然气(LNG)运输船系泊系统及其所用绳缆的发展过程,然后归纳总结绳缆的材料、结构和主要性能指标和选用的基本原则,对钢丝绳缆和化纤绳缆这两大类产品的性能进行了较为详细的比较,显示了化纤绳缆在液化天然气运输船系泊应用中的总体优势。