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随着FPSO在海洋石油开发中的广泛应用,以及其系泊技术逐步趋向成熟,各种系泊方式的应用和研究也相对比较深入。对不同系泊方式进行全面风险分析,相互比较,对于以后选择系泊系统形式和避免现有系泊系统的一些风险是非常重要。基于上述考虑,进行散射系泊方式与转塔式系泊方式的风险对比,乃是极其必要的。 相似文献
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FPSO系泊系统设计上的考虑 总被引:1,自引:0,他引:1
作为具有高科技含量的系泊系统,是FPSO(浮式生产储/卸系统)的关键组成部分.根据不同的环境条件和作业要求,其系泊方式也是不同的.其中单点系泊系统(Single Point Mooring System,简称SPM)用的最多、最普遍.本文从介绍FPSO系泊系统入手,对目前应用较为广泛的几类系泊方式进行了较为详细的介绍.然后结合实际,重点对FPSO单点系泊系统在设计上需要考虑的内容进行了分析.最后对中国海域FPSO系泊系统的应用进行了简单的介绍. 相似文献
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在FPSO的设计中.系泊技术是最为核心的技术之一。适用于FPSO的系泊系统可大致分为如下两类:多点式系泊系统(SMS)和单点式系泊系统(SPM)。 相似文献
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Mark B. Orams 《Coastal management》2013,41(4):361-380
The growth of whale-watching internationally has been spectacular. It now occurs in almost 100 countries and is estimated to be worth in excess of U.S.$1 billion each year in revenue. Thus, whales have become valuable as a resource for tourism. The Vava'u island group in the northern part of the Kingdom of Tonga in the South Pacific is an area with a growing reputation as a whale-watching destination. However, the industry is relatively new there and the impacts of whale-based tourism in these islands is, as yet, unknown. In addition, there has been a recent consideration of a return to hunting whales in Tonga. As a result, concerns regarding the value of these animals for tourism and the potential impact of a return to hunting have arisen. Consequently, a study was designed to provide a preliminary assessment of the economic impacts of these animals for the island community. This study estimates that humpback whales may be worth in excess of U.S.$700,000 annually as a tourism attraction and that there is significant potential for future growth. Furthermore, the study shows that current visitors are opposed to any resumption of whaling practices in the islands and that such a move would likely displace large numbers of tourists from Tonga. Thus, it is concluded that a resumption of whaling in Tonga would likely have a significant opportunity cost in terms of lost tourism revenues. 相似文献
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This article studies the liabilities of a multimodal transport operator under Chinese law. The present legal framework governing the multimodal transport consists of a complex array of laws and regulations. As a consequence, the applicable liability rules, the degree and the extent of the liability of a multimodal transport operator may vary from case to case. In addition, the ratification of the Rotterdam Rules would only contribute to clarification of legal complexities in a multimodal transport case where a sea leg is included. We conclude that there is a need to have a Chinese multimodal transport law which is broad enough in scope to govern the rights and liabilities of all parties involved in multimodal carriage in China. 相似文献
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An alternative option to the traditional grouted joint for wind turbines is a direct steel-to-steel connection, also known as slip joint. In a recently published work, a proof of concept of a vibration-assisted installation and decommissioning technique of a slip joint was illustrated. Leveraging on the obtained results, the current study shows for the first time a decommissioning campaign carried out using a vibration-assisted technique applied on a prototype hydraulic wind turbine tower located in the North Sea, and connected to the monopile through a slip joint. The key aspect of the dismounting procedure is a priori knowledge of the resonance frequency clusters corresponding to the slip joint’s cross-sectional modes. Therefore, field hammer tests and experimental modal analysis were carried out inside the wind turbine tower. The identified frequencies and mode shapes were then compared with numerical ones estimated by a finite element model of the investigated structure. The comparison showed that a set of frequency clusters can be directly selected from a detailed numerical model. The preparatory work of the slip joint decommissioning was then executed by installing electric shaker devices, based on the dynamic identification results, and hydraulic jacks mounted inside the wind turbine tower. A first decommissioning trial was carried out in May 2019, while the final decommissioning was performed in August 2019. After analysing the measurements of the hydraulic pressures, displacements and excitation frequencies during the decommissioning campaigns, the results showed that it is possible to disconnect the slip joint if, in combination to a vertical static force, one of the identified cross-sectional mode shapes is excited. The vibration-assisted decommissioning proved to be a successful technique to dismount the connection in a controlled and straightforward manner. 相似文献
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当船舶发生海难事故后,船舶弃船时机的正确决策关系到船舶安全尤其是海上人命安全,本文分析了影响该决策行为的各种环境因素,对弃船时机的正确选择做一个初步分析,为进一步研究奠定一些基础。 相似文献
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In recent years, demands for car transportation by a ship have been increasing with favorable economic conditions in auto
sector, and the need of a pure car carrier (PCC) has grown quickly. A PCC needs huge parking space but smaller displacement
since a car is comparatively light for its volume. As a result, almost all PCCs have wide breadth, shallow draft and huge
structure above the water surface. These features cause some technical issues of a PCC, like lack of stability, effect of
strong winds on its resistance, difficulty of course keeping in rough seas, difficulty of berthing in strong winds, and so
on. To overcome these technical issues, one of the authors has proposed a new concept for a PCC. This is a trimaran PCC which
has very limited transverse bulkheads in the center hull by using two side hulls as fenders. In the present research, wind
forces acting on a scale model of the trimaran PCC were measured in the towing tank with a wind generator at Osaka Prefecture
University. Furthermore, in order to clarify the characteristics of wind pressure on the trimaran, height and width of tunnels
which are between a main hull and side hulls were changed. And then, in order to imitate a real ship, we used wind reduction
technology of corner-cut design for accommodation house of the ship. Moreover, the wind pressure acting on the trimaran was
compared with that on a mono-hull PCC. Using these experimental and theoretical results, an estimation method of wind pressure
acting on the trimaran PCC is deduced. 相似文献
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In recent years, the dynamic responses of flexible risers have been the focus of many researchers. Most flexible risers undergo a substantial level of irregular motion from environmental loadings, which involves a continuous slip of helical wires. The slip of helical wires especially leads to a hysteretic effect by reducing the bending stiffness, making it hard to predict the dynamic responses of flexible risers. The current study, as an extension to Part I, presents a new large-scale dynamic analysis method for flexible risers. The suggested method creates a large-scale model for the dynamic analysis that considers a geometric and bending nonlinearity of flexible risers. The kinematics of each beam element is formulated based on a Green-Lagrangian strain and the interaction with the seabed, providing a realistic analysis of flexible risers. In particular, the current study introduces a direct moment correction method that modifies the internal force vector using an improved analytical model. The improved analytical model is assigned at each node of the large-scale model and estimates an accurate bending hysteresis curve considering the effect of shear deformation and varying tension. The suggested method corrects the bending moment and shear force of all beam elements based on the bending hysteresis curves obtained from the improved analytical model, by which a complex bending behavior of flexible risers is reflected in a large-scale domain. As a result, this study achieves a more accurate prediction of the dynamic responses and fatigue damage of flexible risers. A new dynamic analysis program, called OPFLEX, is developed herein based on the suggested analysis method. Using the developed program, the current study conducts several numerical investigations to identify the effect of the shear deformation and varying tension. Consequently, it is confirmed that the shear deformation of internal layers reduces the fatigue damage of helical wires by delaying the increase of internal stress. It is also identified that the effect of varying tension deteriorates the fatigue life of flexible risers through a continuous change of contact pressure during bending. 相似文献
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针对长甲板室纵向围壁端部与主船体露天甲板交界处的应力集中问题,采用结构有限元数值分析方法,探讨在空间布置受到限制的条件下,应力集中交界处圆弧型肘板臂长、圆弧半径等参数变化对应力分布和大小的影响,并得到降低应力集中系数的圆弧型肘板参数的最佳值。文中根据研究结果,对某艘实船的长甲板室纵向围壁端部与主船体露天甲板交界处圆弧型肘板进行优选设计,有效地降低了该处的应力集中水平。 相似文献
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Edwin Van Hassel Hilde Meersman Eddy Van de Voorde Thierry Vanelslander 《Maritime Policy and Management》2013,40(2):192-208
In recent years, an increase in the size of the container ships could be observed. The question is how these larger ships will influence the total generalised costs from a port of loading to a destination in the European hinterland. The second question is whether a scale increase of the container ships on other loops, such as a loop from the United States to Europe, has the same impact on the generalised chain costs as on the loop from Asia to Europe. A derived question is which element of the total chain has the highest importance, and whether this balance varies as the ship size changes. In this article, a model is developed that allows answering the above research questions. The model is designed to simulate the cost of a complete loop of a container ship and of a chain that uses that same loop. For the chain cost simulation, the maritime part is determined by the loop. From the ports of loading and unloading, the port container handling and the hinterland transportation costs are also integrated. The model also allows calculating the total chain cost from a point of origin (either a hinterland region or a port) to a destination point (also a port or a hinterland region). An actual container loop of a container shipping company can be introduced in the model. An application is made to two existing container loops, namely from Asia respectively the United States to Europe. It turns out that changing ship does indeed lead to economies of scale, but also that the impact is larger on the Asia–Europe connection than on the US–Europe connection. Furthermore, the maritime component has the biggest share in the total chain cost, but as ship size increases, the shares start getting closer to each other. This research contributes to the existing literature in two ways. First of all, it quantifies the impact of the scale increase of container ships throughout the total chain. Second, this is done from a bottom-up engineering modelling approach. 相似文献