共查询到19条相似文献,搜索用时 171 毫秒
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稠油掺稀集输系统工艺优化 总被引:1,自引:0,他引:1
塔二联所辖稠油油井多采用掺稀降黏的集输方式,稠油集输的效率成了影响油田高效经济开发的主要问题.文中围绕"节能降耗"的研究目标,针对塔二联稠油掺稀集输流程,以系统能耗最小为目标函数,以井口掺稀油量和所掺稀油的温度作为决策变量组合,建立了稠油掺稀集输系统生产运行参数优化数学模型.并用VB语言编制稠油掺稀集输系统生产运行优化... 相似文献
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腐蚀速率的精确预测对于油气集输管道的安全运行具有重要意义。鉴于神经网络算法陷入局部最小值、收敛速度慢和引起振荡效应等问题,同时考虑自适应遗传算法在广泛的空间搜索和向最优解的方向尽快收敛于最优目标的特点,构建了优化的混合算法神经网络模型。利用该模型对多种因素影响下的油气集输管道的腐蚀速度进行了预测研究。实际应用表明:该模型大大提高了网络的学习效率和预测评判的精度,可以作为油气集输管道腐蚀速率预测的良好工具。 相似文献
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针对史南油田进入高含水期给集输系统带来的影响及问题,对集输系统进行了技术改造,实现了原油的不加热输送和密闭集输、污水就地分离、处理、回注,使集输系统适应高含水期生产,采用高效节能的油气处理工艺技术,以较少的投入获得较大的经济效益。 相似文献
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降雪是影响民航冬季运行的典型天气之一,对航班在机场的安全正常运行会造成较大影响。因此,深入分析影响机场冬季运行效率的因素,并建立科学有效的评价方法具有较强的现实意义和应用价值。然而,当前关于此问题缺乏较为全面系统的研究。本文结合近年民航冬季运行保障实际,从资源保障、机制实施、航班运行和除冰雪水平等维度出发,提出了一种机场冬季(降雪)运行效率指标体系和评价方法,应用欧几里得距离函数、层次分析法、有序加权平均算子对指标权重进行组合赋权,采用里克特五级计分法确立评价标准,并通过实例分析验证。结果表明,该评价方法可以较为全面有效地反应机场冬季(降雪)运行保障水平,为运行效率评价提供可参考的思路和方法。 相似文献
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北外环集输管道工程是川渝地区管网建设的重点工程,因此有必要对站场SIS系统的设计情况进行研究,剖析存在的影响安全运行的问题。采用设备硬件改造与系统软件改造相结合的方式,从设计原则、改造方式、ESD逻辑动作、破管检测联锁等多方面详细阐述了技术改造措施,通过现场测试与验证,实现了SIS系统的故障安全性与系统联锁控制,也为类似站场SIS系统改造提供了技术支撑。 相似文献
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智能交通系统(ITS)在港口运营管理中越来越重要,为科学地研究ITS对港口基础设施效率的影响程度,文章从功能、环境和资源三个角度,建立了港口基础设施效率影响的评价指标体系,同时定义了各基础影响指标,采用多级模糊评价模型分析ITS对港口基础设施效率的影响。评价结果能反映我国港口ITS发展情况,对促进我国港口基础设施的可持续发展有一定的指导意义。 相似文献
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Because of China’s rapid economic development, its transportation system has become one of China’s high-energy-consumption and high-pollution-emission sectors. However, little research has been done which pays close attention to China’s transportation system, especially in terms of energy and environmental efficiency evaluation. In this paper, data envelopment analysis (DEA) is applied to measure the energy and environment performance of transportation systems in China with the goal of sustainable development. This paper treats transportation as a parallel system consisting of subsystems for passenger transportation and freight transportation, and extends a parallel DEA approach to evaluate the efficiency of each subsystem. An efficiency decomposition procedure is proposed to obtain the highest achievable subsystem efficiency. Our empirical study on 30 of mainland China’s provincial-level regions shows that most of them have a low efficiency in their transportation system and the two parallel subsystems. There are large efficiency differences between the passenger and freight transportation subsystems. In addition, unbalanced development has occurred in the three large areas of China, with the east having the highest efficiency, followed by central China and then west. Therefore, more measures should be taken to balance and coordinate the development between the three large areas and between the two subsystems within them. Our analysis approach gives data for determining effective measures. 相似文献
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This paper examines the design and efficiency of a highway use reservation system where commuters need reservations to access a highway facility at specific times. We show that, by accommodating reservation requests to the level that the highway capacity allows, traffic congestion can be relieved. Generally, a more differentiated design of the reservation system yields a higher reduction of travel cost and thus achieves a higher efficiency. The efficiency bound of the system is established. We also show that braking or tactical waiting behaviors of drivers would cause a loss of efficiency, which thus need be proactively accommodated. Given that user heterogeneity cause further loss of efficiency, we explore how two specific types of user heterogeneity affect the system efficiency. Auction-based reservation is then proposed to mitigate the efficiency loss. 相似文献
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Each stakeholder in the air transportation system has a different perspective on the performance efficiency metrics, making analysis of system-wide design options very difficult. This paper uses topological structures of service networks to examine trade-offs between efficiency metrics established around the passenger, airline, and air navigation service provider perspectives. The findings indicate that the scale-free type topologies are preferred under most of the metrics. However, with enough density, random topologies become more appealing with its high robustness feature and performance comparable to scale-free. 相似文献
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The transport sector is fast changing with demand for distillates increasing amidst declining gasoline consumption in many markets especially in the developed world. Increasingly refineries are stretched to operate less efficiently and this is manifested through a drop in efficiency as a consequence of increasing diesel production via less efficient routes, particularly on the marginal barrel of diesel. It has been suggested that this decline in diesel production efficiency, as the ratio of gasoline to diesel (G/D) production drops, can partly be mitigated through the use of Gas-to-Liquid (GTL) diesel. In this paper we adopted refinery Linear-Programming models to represent the refining system in Europe as well as a district in the U.S. to investigate the effects of increased availability of GTL diesel to a refiner on the energy efficiency and GHG emissions of refineries. Here we showed that indeed there is an improvement in diesel production efficiency with increasing GTL concentrations, but this efficiency gain (<0.5%) is insufficient to counteract the higher energy consumption and emissions associated with the production of GTL, thus leading to an overall decline in life cycle efficiency (up to 5%), and an increase in life cycle GHG emissions (up to 2%). 相似文献
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Assessing the technical efficiency, service effectiveness, and technical effectiveness of the world’s railways through NDEA analysis 总被引:1,自引:0,他引:1
This paper presents an approach to include both the unstorable feature of transportation service and the technological differences within railway companies in efficiency and effectiveness measurements. We explore efficiency and effectiveness for a group of 40 global railways in the year 2002, using traditional data development analysis (TDEA) and network data development analysis (NDEA). Comparing the results obtained from the NDEA model with those from the TDEA indicate that performance measures are quite different in terms of the magnitude, and even using different DEA type models to evaluate railway system performance does not distort the ranking of their performance. We also analyze the inter-related effects among three performance measures, finding that transportation service characteristics have positive effects on the evaluation of performance. Generally speaking, the NDEA model provides deeper insight regarding the sources of inefficiency and process-specific guidance to railway managers so as to help them improve their railway’s performance. 相似文献
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针对某气田的气质条件,对气田集输管道材料选择进行了专题研究。分析CO2和Cl-的腐蚀机理,选取了碳钢、不锈钢及双相不锈钢材料进行了气体集输管道腐蚀环境耐蚀模拟试验。实验结果表明:碳钢平均腐蚀速率最快,双相不锈钢腐蚀速率最慢。选取了4种不锈钢进行耐点蚀性能试验与评价。结果显示:马氏体不锈钢2Cr13抗点腐蚀能力最差,25Cr双相不锈钢因其抗点蚀、坑蚀能力强,适宜于某气质腐蚀环境。最后,分别从防腐效果和经济角度论证了采用25Cr双相不锈钢作为内部集输管线的材料优于碳钢+缓蚀剂。 相似文献
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There are many studies on container port efficiency and that seek to understand what factors, such as technical and scale efficiency, private versus public terminal management or macro-economic factors, play on the efficiency score of a given port. There are fewer studies that focus on the role played by the inter-port competitive environment. This role remains difficult to assess. In fact, on the one hand, a port subject to high inter-port competition may record higher efficiency scores due to the pressure from the competitive environment. On the other hand, a port subject to high competition may be forced to over-invest and could therefore records a lower efficiency score. This article investigates this issue and examines how the degree of competition measured at different levels (local, regional and global level) impacts the efficiency score of a given container port. To do so, we implement a truncated regression with a parametric bootstrapping model. The model applied to information gathered for 200 container ports in 2007 and 2010 leads to the following conclusions: port efficiency decreases with competition intensity when measured in a range of 400–800 km (regional level); and the effect from competition is not significant when competition is measured at a local (less than 300 km) or at a global (more than 800 km) level. Estimates also show a tendency for ports who invested from 2007 to 2010 to experience a general decrease in efficiency scores, an element which could be explained by the time lag between the investment and the subsequent potential increase in container throughput. 相似文献