LNG项目柔性材料管道保冷施工

随着液化天然气（LNG）项目的不断发展,新型的管道保冷材料被广泛应用。文中结合某LNG项目管道柔性保冷材料的实际施工情况,对柔性保冷材料的施工工艺从环境要求、保冷结构、施工顺序等几个方面进行研究,总结出了最适合的保冷施工工艺,为其他LNG项目管道保冷材料的选型提供参考,为管道保冷施工提供参考。     

LNG长距离管道输送保冷层厚度的计算方法

将几种计算普通绝热低温管道保冷层厚度的方法与LNG长距离输送管道的特点结合并进行分析后,建议采用费用最低的方法计算LNG长距离管道输送的保冷层厚度,同时建立了计算保冷层厚度的数学模型,并对该模型进行了分析求解。     

LNG管输保冷层厚度优化设计

对于低温液化天然气输送管道,保冷层厚度的设计是防止管道内液体气化,实现液体单相流动的关键.文中以液化天然气管道年保冷层投资的分摊费用和运行费用之和为优化目标,同时考虑防止保冷层外表面结露,允许最大冷损失量,限制液化天然气进入冷却站温度3个约束条件,建立液化天然气保冷层厚度计算的优化模型,并用Visual Basic语言...     

LNG低温管托的结构特点及材料选用

LNG(液化天然气)在输送过程中,冷量泄漏易汽化产生BOG气体,会严重影响接收站的经济收益。在设计过程中,考虑低温管托需承重,其选用的保冷材料与管道本体不同,选择合适的结构和材料,可以最大限度地减少冷量泄漏。文中介绍一种低温管托的设计要求、结构特点和材料选用,该管托在实际应用过程中表现出良好的保冷性能且施工方便,值得推广应用。     

LNG在运输船舶上的应用

近年来,随着我国内河船舶运输发展,燃油消耗不断增加,排放问题日益突出。柴油-LNG双燃料船舶正是在此形势下发展起来的一项先进技术。该项目是探究以柴油–LNG双燃料替代柴油单一燃料,在保持原有柴油机主体结构和燃烧方式不变的前提下,增加一套LNG供气系统和柴油–LNG双燃料电控喷射系统,通过电子转换开关,实现单纯柴油燃料状态下和油气双燃料状态下两种运行模式的转换。双燃料船舶,在混合动力模式下,烟尘、废油水的排放都大为降低,噪声也有所降低。该技术的广泛应用,将有利于调整优化内河航运能源结构,符合国家节能减排、低碳发展的政策要求,有利于发展绿色水运。     

管道多层反射结构保温性能影响因素分析

文中建立了管道多层反射保温结构传热模型,并对保温性能影响因素进行了分析.以超细高温玻璃棉为反射屏间隔保温材料,加入反射屏后,保温结构外表面温度及散热损失均降低.在200℃时,DN200管道添加3层反射屏相对于无反射结构减少了17.5％的散热损失.当反射屏层数相同时,管道温度越高,反射保温结构的节能效果越明显.在100℃...     

“量身定制”的优质工程

前不久,2013年度浙江省"钱江杯"优质工程榜单出炉,三航局宁波分公司承建的浙江LNG码头工程榜上有名。施工过程中,建设者们充分考虑工程实际,依据项目特色"量身定制"施工工艺,为优质完成施工任务奠定了基础。浙江LNG码头工程是浙江省第一     

马平高速公路路面沥青混凝土下面层施工

本文介绍了马平高速公路的路面结构，并对沥青混凝土下面层的施工程序、施工工艺、质量控制及施工注意事项做了较为详细的介绍，供大家参考。     

催化装置反再系统设备的保温改进

催化装置三旋和再生器通过外部保温,防止钢壁烟气结露导致的裂纹产生,保温质量的好坏直接影响到三旋、再生器的安全运行。结合催化装置三旋、再生器的保温更换,根据三旋、再生器的实际情况,制定了相应的设计原则和目标,然后选定保温材料,再根据所有数据参数计算出所需要的保温层厚度,并制定保温的施工工艺。通过对保温的改进,改善保温效果,提高催化装置三旋和再生器安全运行时间。     

章村桥胶粉改性沥青防水粘结层施工技术研究

为了研究胶粉改性沥青防水粘结层的施工工艺以保定章村桥为依托,对桥面界面处理方式、施工工艺及相关指标的控制等内容进行了研究。研究表明,胶粉改性沥青防水粘结层的施工工艺较普通沥青材料复杂,对工艺技术要求较高。通过研究提出了胶粉改性沥青防水粘结层的施工中关键点及相关控制指标,并针对施工中可能出现的问题提出了预防措施。     

车载LNG储罐BOG回收研究

本文提出了在液化天然气客车上增设BOG储罐以回收利用蒸发损失的方案。通过计算百分百回收BOG时的理想蒸发率值可以知道,现有蒸发率仍有较大改善空间;通过维持时间的计算发现,由于新增的储罐对整车的维持时间增加少于一天,BOG回收效果并不显著,未来提高保温性降低蒸发损失或采用ANG吸附回收,是更有价值的研究方向。     

Real option analysis for environmental compliance: LNG and emission control areas

A wide array of technical and operational solutions is available to shipowners in order to comply with existing and upcoming environmental regulation within Emission Control Areas (ECAs). Liquefied Natural Gas (LNG) is a promising alternative since it offers potential cost savings in addition to ensuring compliance with ECA regulation. But investment to retrofit existing vessels to be able to use LNG carries significant upfront costs, and a high degree of uncertainty remains on the differential between the prices of LNG and conventional maritime fuels, as well as on the availability of LNG and the reliability of its supply chain. New technologies such as LNG inherently carry substantial risk and an ill-chosen investment strategy may have irreversible consequences that could jeopardise the future of the shipping company. One important question is whether interested owners should invest in LNG now to comply with ECA rules in 2015 and reap the benefits of lower LNG prices, or whether it would be advisable to wait until some of the uncertainty is resolved.While traditional discounted cash flow techniques are unable to account for the value of managerial flexibility linked, for example, to the possibility of deferring an investment, real option analysis can be used to analyse such cases. The paper discusses the optimal time for investment in LNG retrofit and takes specific account of the value of an investment deferral strategy versus the advantages obtainable from the immediate exploitation of fuel price differentials. Through the use of a real option model the paper shows that there is a trade-off between low fuel prices and capital expenses for investment in LNG retrofit. The development in LNG is critically dependent on its future price as well as the reduction in capital costs and ship retrofitting costs. In this respect, policy makers can play a critical role in providing support to advance technical knowledge, maintain LNG prices at favourable levels and in avoiding ambiguity on regulation.     

Excess Commuting: A Critical Review

Abstract

The stringent ship emission regulations under IMO's (International Maritime Organization) MARPOL Annex VI are a main driver to consider liquefied natural gas (LNG) as a ship fuel. Research into LNG as a marine fuel saw a strong growth in recent years, but no study has analyzed in a systematic way the level of convergence among the findings presented in the wide range of studies. In order to fill this gap, this paper seeks to perform a systematic review to synthesize the findings of 33 published studies on the use of LNG as a ship fuel. The aim is not only to obtain a much broader understanding of the current perspectives and challenges for applying LNG as a bunker for ship propulsion, but also to identify the gaps and weak points in the literature which could suggest future research. Moreover, given the output of the synthesis, the paper presents an extensive decision-making framework for shipowners when deciding on a fuel switch for their fleet from conventional oils to LNG in order to achieve a level of conceptual development beyond that attained in individual studies. In addition, the study also identifies the important role of ports in facilitating and encouraging the large-scale adoption of LNG in the maritime industry.     

Probabilistic analysis of the release of liquefied natural gas (LNG) tenders due to freight-train derailments

Liquefied natural gas (LNG) has emerged as a possible alternative fuel for freight railroads in the United States, due to the availability of cheap domestic natural gas and continued pursuit of environmental and energy sustainability. A safety concern regarding the deployment of LNG-powered trains is the risk of breaching the LNG tender car (a special type of hazardous materials car that stores fuel for adjacent locomotives) in a train accident. When a train is derailed, an LNG tender car might be derailed or damaged, causing a release and possible fire. This paper describes the first study that focuses on modeling the probability of an LNG tender car release incident due to a freight train derailment on a mainline. The model accounts for a number of factors such as FRA track class, method of operation, annual traffic density level, train length, the point of derailment, accident speed, the position(s) of the LNG tender(s) in a train, and LNG tender car design. The model can be applied to any specified route or network with LNG-fueled trains. The implementation of the model can be undertaken by the railroad industry to develop proactive risk management solutions when using LNG as an alternative railroad fuel.     

LNG燃料动力船在广西内河推广应用的思考

文章分析了液化天然气(LNG)在航运业推广应用的必要性和以LNG作为船舶动力燃料的主要危险特性,介绍了国内外LNG燃料动力船改造应用的基本情况及难点,提出了广西内河现有船舶进行LNG动力改造面临的主要问题与对策,为LNG燃料动力船在广西内河的推广应用提供参考。     

LNG汽化站的工艺设计

论述了液化天然气汽化站的工艺流程,主要针对LNG汽化站主要设备的工艺设计问题进行探讨,并介绍了LNG汽化站的安全设计.     

天津港典型LNG码头海洋环境风险研究

文章针对天津港特殊的地理位置,周边敏感资源的特点,对天津港典型LNG码头的运输货种及燃料油的污染危害性进行了分析,对码头及船舶存在的风险进行了研究。运用Oilmap溢油轨迹和归宿模型,采用情景分析法假定溢油事故场景,对燃料油泄漏事故进行了模拟。根据研究结果,对天津LNG码头提出了风险的防范措施以及建议。     

A hybrid heuristic strategy for liquefied natural gas inventory routing

As liquefied natural gas (LNG) steadily grows to be a common mode for commercializing natural gas, LNG supply chain optimization is becoming a key technology for gas companies to maintain competitiveness. This paper develops methods for improving the solutions for a previously stated form of an LNG inventory routing problem (LNG-IRP). Motivated by the poor performance of a Dantzig-Wolfe-based decomposition approach for exact solutions, we develop a suite of advanced heuristic techniques and propose a hybrid heuristic strategy aiming to achieve improved solutions in shorter computational time. The heuristics include two phases: the advanced construction phase is based on a rolling time algorithm and a greedy randomized adaptive search procedure (GRASP); and the solution improvement phase is a series of novel MIP-based neighborhood search techniques. The proposed algorithms are evaluated based on a set of realistic large-scale instances seen in recent literature. Extensive computational results indicate that the hybrid heuristic strategy is able to obtain optimal or near optimal feasible solutions substantially faster than commercial optimization software and also the previously proposed heuristic methods.