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临濮输油管道的部分管段因遭受多次第三方破坏,造成管线泄漏.为在不停输情况下带压封堵,提高封堵效率,研制低压封堵器摘取泄漏处阀门进行封堵作业.详细介绍了低压封堵器的研制方法、装置结构和封堵技术关键作业步骤.在成品油和原油管道抢修作业中,低压封堵器的使用能减少工时10% ~ 62.5%,将施工人数减少至1人,未发生跑油、冒油现象,保护了管道周边环境. 相似文献
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介绍了运用VB编程实现常温输油管道的工艺计算与工况模拟技术。该软件具有数据输入,处理和水力工况模拟等方面的功能,该软件处理各咱数据快捷、有效,具有一定的产用价值。文中还阐述了输油干线水力工况模拟软件的结构和使用方法。 相似文献
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管道不停产带压开孔封堵新技术自带旁通筒式封堵设备 总被引:3,自引:0,他引:3
包括电动贯通式开孔机、自带旁通筒式封堵机及特制四向三通、铁屑回收器等配套设备。开孔刀为套筒形,能将开孔刀切割下的料片随筒刀一起从管道上提取出来,封堵时,又放回切割料片并复位固定,保持管道尺寸形状,利于管内作业。封堵机自带旁通,免去了另开旁通口和平衡口,全部开孔封堵作业过程只需开3个口,堵2个口,施工费用节省一半以上。 相似文献
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气囊式封堵是管道不停输封堵技术中的一种新的方式,它适用于城市低压燃气管网管线和供水管道的带压开孔封堵作业。橡胶气囊式封堵的关键技术是气囊的结构形式和被封管道内部气囊所处位置的预先清理,即开孔切削时铁屑散落于管道内腔底部和管道内部原有的沉积物的清理。文中介绍了气囊式封堵的基本原理,设备的构造特点和应用方法。 相似文献
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介绍了定向钻穿越控制系统、主要施工程序、作业原理和作业方法。按照以上方法,并结合现场的实际情况,对盘-锦输油管道的绕阳河和东郭镇鱼塘进行了定向钻穿越施工,取得了一次性成功。总结了该定向钻穿越施工的成功经验。 相似文献
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文中概述了目前国内外天然气长输管道应急封堵技术发展的现状,并通过理论分析与工程实践,对常用的4种管道应急封堵技术从技术原理、施工工艺、施工特点等方面进行了简单对比。而后重点介绍了带压开孔-旁通封堵技术的原理、施工工艺,并通过分析得出结论,带压开孔-旁通封堵技术具有应用范围广、可靠性高、不需停输等优点,适用于天然气长输管道的应急封堵作业。 相似文献
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Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD). An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip. It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links. 相似文献
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This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress. 相似文献
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介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。 相似文献
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明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。 相似文献
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天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本. 相似文献
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Joseph N. Prashker 《Transportation》1979,8(4):329-346
Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area. 相似文献