先导式安全阀在输气站场中的选型应用

先导式安全阀因具有开启迅速、回座稳定并且密封性能好等优点,现已广泛应用于各输气站场中。因而,在输气站场中正确选择先导式安全阀至关重要。为了给输气站场中安全阀的设计选型提供参考,文中介绍了先导式安全阀的优点、结构特点、工作原理及选型步骤,并以某输气站场中先导式安全阀的实际计算选型为例,通过逐步分解计算,得出安全阀通道面积,并最终选择合适型号的先导式安全阀。     

严寒地区油库压力管道选材研究

根据工业管道安全技术监察规程,严寒地区油库压力管道设计温度低于-20℃,超出了20号碳素钢管的使用温度下限,按照压力管道设计规范中关于低温低应力工况的定义,进行管道应力计算。分析表明：油库压力管道的设计压力低于0.7 MPa时,油库管道正常操作的轴向拉应力低于材料标准规定的20号钢管的最小抗拉强度值的10%,管道操作工况处于低温低应力工况,管道材料可以使用20号钢。     

油库自流作业时最小高差的确定

油库的自流作业是利用油品的自然位差能进行的作业过程。提出了满足最小位差的计算方法和确定条件,指出了油库自流作业时应考虑的主要问题,即对油库的作业方式、工程施工、经济性、运行管理、自动控制等方面的影响及主导油管线的工艺设计指导原则等,对油库设计与建设有一定的指导意义。     

成品油管道枢纽站罐容计算方法研究

目前国内成品油管道枢纽站的罐容还没有明确的计算方法,大多参照GB50253《输油管道工程设计规范》中的相关规定进行确定,计算的罐容往往过大,建设用地多,造成工程投资偏高。以兰郑长成品油管道咸阳油库为例,通过对咸阳油库各种运行工况的分析,引用流量差的概念,阐述了一种成品油管道枢纽站罐容计算方法。并和参照《输油管道工程设计规范》罐容计算结果进行了经济对比。对比结果表明:阐述的罐容计算方法经济适用,可用于今后类似成品油管道枢纽站罐容的确定。     

油田内部热油管道最佳操作参数的快速确定

由于油田内部热油管道操作参数上的不合理,给油田生产造成了不必要的能量损耗。利用管道分段的方法,通过热力和水力计算,生成出站参数曲线图,方便快捷的为油田内部的热油管道确定最佳的出站（管道起点）加热温度和出站压力,减少能源的浪费。计算中,考虑了流量、含水量、黏度变化等因素,为流量和含水量不断变化的油田内部加热输油管道的优化运行提供参考。     

运用盾构掘进参数跟踪判断滚刀损坏的研究

目前盾构滚刀磨损的判断通常是经验性的。文章在文献[6]运用盾构掘进参数判断刀具损坏的分析计算方法基础上,进一步考虑了土舱压力的影响,对掘进速度和刀盘扭矩计算模型进行了修正;依托具体工程实例,运用修正计算模型分别对土压平衡盾构、泥水平衡盾构以及TBM等在硬岩中的掘进数据与滚刀情况进行了跟踪判别研究。结果表明,计算结果与滚刀磨损情况比较吻合,该方法对判断滚刀损坏具有可行性、参考性。     

盾构掘进参数对地表沉降的影响分析

盾构法作为地铁隧道施工的一种主要施工方法已在我国得到广泛的应用,由施工引起的地层移动和地表沉降是盾构隧道设计和施工中备受关注的问题.文章以深圳地铁5号线洪浪-兴东盾构区间下穿广深高速公路立交桥隧道施工为工程依托,通过数值模拟和现场监测,对影响地表沉降的掘进参数进行了模拟分析.计算结果表明,地表下沉与盾构掘进参数密切相关,适当加大注浆压力能有效控制地表沉降;同时,土舱压力与土体原始侧向压力接近时地表沉降量最少.实测地表沉降与掘进参数的关系表明,当注浆量一定时,地面沉降随土舱压力的增加而减小;地表沉降随着注浆量及注浆压力的增大而减小.     

HAZOP方法在液氢储供系统中的应用

文中以液氢储罐"压力过高"偏离为例,详细描述了HAZOP分析过程,将人员、财产和社会风险均降至可接受风险水平.液氢储供系统划分为3个节点,针对各节点得出分析记录表,提出相应的安全措施和建议.液氢储罐和管路必须安装安全阀,液氢储罐还应安装爆破片.液氢试验过程必须配备氢浓度监测设备,建议在开敞通风的环境中进行.     

加氢装置反应器安全阀管线的应力分析

加氢装置反应器工作温度较高,为保证其顶部安全阀管道在设计条件下具有足够的柔性,并防止管道因热胀冷缩、端点附加位移、管道支承设置不当等原因引起管道应力过大或管道破坏等现象,利用CAESARⅡ对加氢装置中的反应器顶安全阀管线进行应力分析。得出结论:改变管子的走向,增加π型弯,可以增加安全阀管线的柔性,减少热位移对管系影响,从而设计出合理的安全阀配管方案。     

输油管线防凝固软件的开发与应用

人从黄岛码头至黄岛油库（齐润）ＤＮ８００原油管线为间断输送，设计中存在原油冷却凝固及伴热防凝的问题，本文阐述了软件的数学模型，进行了温度场的计算、解凝时间计算、各个温度条件下热损失的计算以及原油凝固时间计算等。经与中国管道科学研究院提供的实验数据比较，计算结果与实验数据十分吻合。本软件可应用到输油管线的伴热、解凝以及生产中。     

管道带压堵漏技术及其在油库中的应用

概述了油库发生泄漏的危害和带压堵漏技术在国内的发展情况,对常用的3种带压堵漏技术进行了简单对比。文中重点介绍了带压注剂堵漏技术的原理、施工工艺、注意事项,并通过实例指出带压注剂堵漏技术应用范围广泛、可靠性高、不需动火,适用于油库库内管道的不停产堵漏。     

储罐机械清洗设备清洗工艺与应用

清洗作业是储罐运行中的一项重要工作,可保证储罐的正常运行。介绍了储罐机械清洗技术工作原理,储罐机械清洗较人工清洗具有显著的优势。介绍了清洗设备主要构成,分析了原油储罐清洗的主要工艺流程。结合吐哈油库20#原油储罐油质的特点和现场具体情况,制定了专项清洗方案,给出此次原油储罐清洗的具体工艺流程。应用上述工艺流程,能够更快更好地满足储罐的清洗要求,节省了人力、物力和财力,创造更多的效益。     

Optimization of bus allocation to depots by minimizing dead kilometers

In metropolitan cities, public transportation service plays a vital role in mobility of people, and it has to introduce new routes more frequently due to the fast development of the city in terms of population growth and city size. Whenever there is introduction of new route or increase in frequency of buses, the non‐revenue kilometers covered by the buses increases as depot and route starting/ending points are at different places. This non‐revenue kilometers or dead kilometers depends on the distance between depot and route starting point/ending point. The dead kilometers not only results in revenue loss but also results in an increase in the operating cost because of the extra kilometers covered by buses. Reduction of dead kilometers is necessary for the economic growth of the public transportation system. Therefore, in this study, the attention is focused on minimizing dead kilometers by optimizing allocation of buses to depots depending upon the shortest distance between depot and route starting/ending points. We consider also depot capacity and time period of operation during allocation of buses to ensure parking safety and proper maintenance of buses. Mathematical model is developed considering the aforementioned parameters, which is a mixed integer program, and applied to Bangalore Metropolitan Transport Corporation (BMTC) routes operating presently in order to obtain optimal bus allocation to depots. Database for dead kilometers of depots in BMTC for all the schedules are generated using the Form‐4 (trip sheet) of each schedule to analyze depot‐wise and division‐wise dead kilometers. This study also suggests alternative locations where depots can be located to reduce dead kilometers. Copyright © 2015 John Wiley & Sons, Ltd.     

Depot location in degradable transport networks

Areas subject to natural or man-made disasters, such as earthquakes, fires, floods or attacks, are reliant on the residual transport network for the rescue of survivors and subsequent recovery. Pre-disaster planning requires assumptions about how the transport network may degrade. This paper presents a game theoretic approach modelling network degradation and applies this to depot location, with a case study based on Sichuan province in China, which is prone to earthquakes. To facilitate a cautious approach to depot location, the method assumes that the transport network is subject to attack by node-specific demons with the power to degrade links. The mixed strategy Nash equilibrium for the non-cooperative zero sum game between dispatchers and demons is used to define rescue hyperpaths. These in turn define the best depot locations. Two forms of the drop heuristic are used to find good depot locations.     

GIS测绘系统在油气管道安全运行中的应用

油气管道是连接油田、炼厂上下游的重要部分,油气的安全输送是保证油气产量的关键。油气管道运行时的内外部因素给管道安全带来隐患,在油气管道安全运行中引入GIS测绘系统,采集油气管道安全管理相关数据,并对数据进行分析和处理,为管道安全运行提供了决策依据,有效地消除了管道运行安全隐患。     

Evaluation of total risk exposure and insurance premiums in the maritime industry

The empirical evaluation of maritime risk exposure is based on the monetary value at risk (MVR) that incorporates individual safety quality data of about 130,000 vessels, insurable values related to various potential damages, and proxies for fractions of values lost at incidents. MVR provides a tool to enhance strategic planning of maritime administrations and insurance providers, which is illustrated by a high level comparison of annual risk exposure with insurance premiums for 2010–2014. The analysis reveals a global annual insurable value of 30.6 trillion USD with associated annual MVR of 38.8 billion USD for very serious and serious incidents. Although oil tankers show the highest risk exposure (1.75 million USD per tanker per year), safety qualities are found to be best for this ship type (1.4% annual incident risk) and worst for container vessels (2.8%). Annual growth rates in total risk exposure are mostly positive with highest value for dry bulk carriers (27.8%), whereas risk exposure tends to decline for pollution of oil tankers (−2.0%) and passenger vessels (−11.3%), and for loss of life of oil tankers (−1.9%) and dry bulk carriers (−1.4%). Comparison across administrative dimensions reveals that most risk exposure lies with old open registries and with beneficial owners and the Document of Compliance companies located in high income countries. Comparison with global insurance premiums suggests reasonably adequate coverage of maritime risks (excluding cargo) with under-insurance of risk by around 5% (about 1 billion USD per year), with some uncertainties remaining for actual loss fractions of the involved damages.     

The impact of depot location,fleet composition and routing on emissions in city logistics

This paper investigates the combined impact of depot location, fleet composition and routing decisions on vehicle emissions in city logistics. We consider a city in which goods need to be delivered from a depot to customers located in nested zones characterized by different speed limits. The objective is to minimize the total depot, vehicle and routing cost, where the latter can be defined with respect to the cost of fuel consumption and CO₂ emissions. A new powerful adaptive large neighborhood search metaheuristic is developed and successfully applied to a large pool of new benchmark instances. Extensive analyses are performed to empirically assess the effect of various problem parameters, such as depot cost and location, customer distribution and heterogeneous vehicles on key performance indicators, including fuel consumption, emissions and operational costs. Several managerial insights are presented.     

Optimal location of transshipment depots

A number of agricultural commodities are either transported once harvested to a destination outside the production region or processed (or consumed) at a centrally located facility within the production region. One or more depots (or assembly points) can be located optimally within the harvesting region to reduce the overall shipment costs when transshipment at a lower freight rate can be achieved from the depot. Processing at the depot to concentrate the commodity, or to select desired fractions from the raw material, can achieve additional reductions in freight costs and increase the economic benefit.A model based on a circular harvesting region with uniform production per hectare and a linear transport function was used to define the optimal location of the depots. In the case of transshipment out of the supply region, a single depot was considered. A transshipment depot can be placed within the supply region for a net reduction in transport costs as long as the transshipment freight rate is less than approximately 85% of the collection freight rate.For transshipment to a central processing facility, the supply region was divided into uniform sectors and the optimal depot placement in a sector was located. Given a non-negative transshipment freight rate and that all production passes through the depot, the optimal depot placement cannot lie beyond 70.7% of the radius. A minimum reduction in the ratio of the freight rates is also required for the shipment point to move from the centre of the region to within a sector. Division of the production region into an infinite number of sectors was examined and it was found that convergence to the maximum benefit (at infinite number) was rapid so that, with just eight or nine sectors, 80% of the limiting benefit was obtained. The model was developed with the harvesting of milk in mind, but appears to relate to a wide range of harvestable low value bulky agricultural commodities.For a circular harvesting region, it was found that the economic benefit varied as the cube of the radius of the production region and linearly with the production intensity, regardless of whether transshipment was internal or external. The economic benefit was quantified for both variants of the model using selected parameters pertinent to milk harvesting.     

Safety modeling for two‐way left‐turn lanes and a procedure to identify two‐way left‐turn lane segments with safety concerns

In the past, two‐way left‐turn lane (TWLTL) median treatments have been frequently used in Florida to inexpensively improve traffic and safety performances. In order to identify factors that may have significant impacts on safety operations in TWLTL sections and to identify TWLTL locations that present existing and future safety concerns, a research project was carried out and results are summarized in the paper. In the research, a three‐year crash history database with crashes and section characteristics from a total of 1688 TWLTL sections all over Florida was developed and used. A negative binomial regression model was developed to determine the statistical relationship between the number of crashes per mile per year and several variables such as traffic volume, access density, posted speed, and number of lanes. In regard to the methodology, in order to identify locations with safety concerns, several steps are needed: development of real crash data distribution, determination of statistical distribution models that better represent the actual crash data, determination of percentile values for the average number of crashes, estimation of crash rates for sections with the same characteristics, estimation of critical values for the variables corresponding to the percentile values for average number of crashes, calculation of tables of critical average annual daily traffic values, and generation of a list of TWLTL locations with critical safety concerns. Results presented in the paper have been used in real applications. Copyright © 2012 John Wiley & Sons, Ltd.