液化天然气船舶低速双燃料发动机推进系统设计方法研究

发布时间：2018-03-22 05:12

本文选题：液化天然气　切入点：闪蒸汽　出处：《大连海事大学》2016年硕士论文　论文类型：学位论文

【摘要】：对液化天然气不断增加的需求和越来越严格的排放标准,使得对LNG运输船的推进系统的选型设计由常规的双燃料蒸汽涡轮转变到如今的二冲程双燃料机。论文的目的是为一艘147210立方米,简称LNG的船舶设计和选择合适的二冲程双燃料推进系统,用于替换最初的蒸汽涡轮推进系统。本文研究了影响液化天然气运输船推进系统设计和选择的各种因素,对比了典型的单一燃料柴油机和传统的蒸汽涡轮推进系统,进一步对二冲程低速推进系统的设计和选择进行了研究。首先介绍了推进系统设计的理念,并将闪蒸汽(BOG)处理作为选择液化天然气运输船推进系统的主要标准。然后分析了现有LNG船推进系统的利弊,阐述了整个推进系统的设计过程,同时也指出了LNG船推进和推进系统评价参数的具体差异。再次给出了设计和选择该船舶推进系统的严谨方法。为了快速有效地计算船舶阻力,运用了分析和估算的方法,类比Holtrop和Mennen方法运用简单if循环在Excel电子表格中进行编程从而得出结果,并与瓦赫宁根B系列图表中的螺旋桨敞水特性曲线的结果进行对比,用简单if循环编程在Excel上绘出了特性曲线。通过比较后发现,相比单一燃料柴油机和传统的蒸汽涡轮推进装置,所选的二冲程低速推进系统的生命周期成本(LCC)具有明显的优势。最后介绍了相应轴系的设计,采用了高强度、高耐蚀材料(Aqualoy22),符合ABYC标准和劳氏船级社运输规则,从第一原则对轴系进行了综合扭矩实验和应力分析,简要说明了二冲程推进系统相关的振动问题。由于液化天然气的全球需求猛增导致LNG运输船越来越大,该研究揭示了在此趋势下采用二冲程双燃料推进系统作为LNG运输船最合适的推进系统的优势。在可预见的未来,无论在航运还是在整个运输行业领域,作为气体燃料的液化天然气将成为传统液体燃料的替代品从而扮演重要的角色。
[Abstract]:Increasing demand for liquefied natural gas and increasingly stringent emission standards, The design of the propulsion system for the LNG carrier has been changed from a conventional dual-fuel steam turbine to a two-stroke two-fuel turbine. LNG's ship design and selection of a suitable two-stroke dual-fuel propulsion system is used to replace the original steam turbine propulsion system. Various factors affecting the design and selection of the propulsion system for liquefied natural gas carriers are studied in this paper. Compared with the typical single fuel diesel engine and the traditional steam turbine propulsion system, the design and selection of the two-stroke low-speed propulsion system are further studied. Firstly, the concept of the propulsion system design is introduced. Then the advantages and disadvantages of the existing LNG ship propulsion system are analyzed, and the design process of the whole propulsion system is described. At the same time, it also points out the concrete difference of the evaluation parameters of the propulsion and propulsion system of LNG ship. Again, the rigorous method of designing and selecting the propulsion system of the ship is given. In order to calculate the resistance of the ship quickly and effectively, the method of analysis and estimation is used. The analogous Holtrop and Mennen methods use simple if cycles to program in Excel spreadsheets to obtain the results, and to compare the results with the open water characteristic curves of propellers in the Wageningen B series diagram. The characteristic curves are drawn on Excel by simple if cycle programming. Compared with single fuel diesel engine and traditional steam turbine propulsion, The life cycle cost of the selected two-stroke low-speed propulsion system has obvious advantages. Finally, the design of the corresponding shafting is introduced, and the high strength and high corrosion resistance material, Aqualoy 22, is adopted, which conforms to the ABYC standard and the Lloyd's Classification Society transport rules. Based on the first principle, the comprehensive torque test and stress analysis of the shafting are carried out, and the vibration problems related to the two-stroke propulsion system are briefly explained. Because of the rapid global demand for liquefied natural gas (LNG), the LNG carrier becomes larger and larger. The study reveals the advantages of adopting a two-stroke dual-fuel propulsion system as the most appropriate propulsion system for LNG carriers under this trend. In the foreseeable future, both in shipping and in the entire transport industry, Liquefied natural gas (LNG), as a gas fuel, will play an important role as a substitute for conventional liquid fuels.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U664

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