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介绍成品油长输管道运行中平板闸阀阀杆和阀杆密封被油品中的坚硬杂质刮伤的情况,对故障原因进行分析并提出了对平板闸阀阀杆密封的改造设想,并建议阀门生产厂家根据现场设备的运行状况改进阀杆密封设计,使阀门能适应高杂质环境下的工况要求。 相似文献
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根据管道运行中产生的杂质情况,对杂质的形成、种类及成分进行了分析,阐述了青济邯成品油管道杂质对输油泵、过滤器、管线、阀门、交接计量以及油品质量等多个方面的危害。针对管道杂质的危害,提出了管道清管、改进过滤器结构、调整输油设备维护周期以及实施内防腐等对策,大幅度提高了成品油管道运行输量和成品油管道的运行效益。 相似文献
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随着成品油需求量和炼油厂加工量的增加,现有成品油管道有时不能满足输送量的要求。为了降低投资,国内外一般优先考虑采用管道增输的方法来解决输送能力不足的问题。文中介绍了国内外常用的几种成品油管道增输技术,包括优化泵站特性、铺设副管及复线、添加管道减阻剂、管道内防腐涂层技术等。文中对各种增输技术的增输原理、优缺点、适应场合、带来的经济效益等进行了分析对比,总结了一套确定成品油管道最优增输方案的理论方法,并通过公式推导出输量增加倍数在不同范围时应采取的增输措施,为成品油管道增输措施的选择提供了依据。 相似文献
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通过对成品油管道油品切换操作、清管污油处置等工作上的特殊性进行分析,对混油拖尾、油源质量潜力及回掺设备选型对成品油管道混油回掺工作产生的影响进行总结,对质量流量计标定设施的设计缺陷进行研究。华北成品油管网有针对性地在油品注入流程、混油处置设施及质量流量计标定设施等站场工艺上采取改进措施,达到防止注入油品窜油、混油全部回掺处理及质量流量计在线标定正常投用的目标。同时,提出增加成品油管道混油处理能力、设置清管污油专项处理设施的设计建议,指出在成品油管道站场工艺设计阶段应考虑成品油管道的特殊性,以提高管道的适用性。 相似文献
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成品油顺序输送管道混油量的计算是设计和管理顺序输翔实管道的关键。本文根据两种不同的沿品在管路内交替时产生混油的机理及成品油顺序输送管道的运行经验,采用数值积分的方法编制出长距离成品油顺序输送管道混油量的计算程序。 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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《Transportation Research Part A: General》1991,25(6):407-418
The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda. 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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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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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
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