Strategic planning optimization for natural gas to liquid transportation fuel (GTL) systems

A strategic planning optimization model is proposed for a network of natural gas to liquids (GTL) systems, and it is solved using a rolling horizon strategy. The model formulation determines the strategic and tactical decisions of the GTL supply chain over a long time horizon. The decisions to build new GTL refineries may be made over the span of 30 years and their operations cover the span of 60 years. Multiple capacities of GTL refineries (i.e., 1, 5, 10, 50, and 200 thousand barrels per day) that produce gasoline, diesel, and kerosene commensurate to the United States demand ratio may exist in the network. The parameter inputs include the locations, availabilities, and prices of natural gas in the United States discretized by county, the delivery locations of fuel products, and the transportation costs of every input and output of the refinery, defined for each time period. Formulated as a large-scale mixed-integer linear optimization (MILP) model, the problem is solved using a rolling horizon strategy for tractability. Case studies on the state of Pennsylvania are presented for different planning schemes and their impact on the economic performance of the GTL network is discussed.     

Systematic approach for recognizing limiting factors for growth of biomethane use in transportation sector – A case study in Finland

In this paper, limiting factors for increased use of biomethane as a transportation fuel are studied. The aim of this research is to recognize and estimate the limiting factors for biomethane utilization in the transportation sector. The limiting factors are studied by using calculation models from Life cycle perspective and literature reviews. According to the results, the main limiting factors can be classified into the following categories: production potential, technology, economy or policy. For biomethane utilization in Finland, the main limiting factors seem to be the lack of distribution infrastructure in northern parts of the country and the uncertain economical feasibility for agricultural biomass producers and for vehicle owners. From the political perspective, the external costs for petrol operated vehicles are higher than for biomethane operated vehicles. Reductions from the external costs could be used by political decisions as a base to support the growth of biomethane in the transportation sector which could lead to GHG emission reductions. A similar systematic approach can also be used to study limiting factors for other transportation energy systems.     

浅谈延迟焦化装置露天栈桥的设计

根据延迟焦化装置露天栈桥的工程设计实践,围绕一炉两塔(一个加热炉两个焦炭塔)的焦化装置,分析了露天栈桥设计中的要点及难点,对其在平面布置、基础安排和吊车梁选型等设计方面做一些介绍和论述。     

The hydrogen economy, fuel cells, and electric cars

Hopes have again been raised about developing a “hydrogen economy”, in which hydrogen could be expected to replace oil and natural gas for most uses, including transportation and heating. It is again being claimed that hydrogen will be a widely available, clean, safe fuel. This article argues that such expectations are almost certainly illusory. Hydrogen, like electricity, is not an energy resource but an energy carrier. It takes more energy to extract hydrogen from water than burning the hydrogen can ever provide. There are also inevitable losses in storage, transmission, and final mechanical or heating applications. The question then turns on the efficiency—and safety—of the entire chain of conversion, from the energy source (fossil, solar, or other) to the final use. Moreover, energy sources (preferably renewable, for the long term) can be used for the direct creation of electricity, which can be introduced into the existing grid without requiring a vast investment in a new hydrogen distribution system. In addition, a hydrogen-based system would be unacceptably dangerous. This report will present a detailed technical and economic analysis of the problems with the proposed hydrogen economy and the advantages of some alternatives, principally electricity-based. A hypothetical case of what would be required for a hydrogen filling station serving the general public is closely examined.     

智能材料电流变流体在运输包装中的应用研究

在深入分析缓冲运输包装基本理论基础上，并将研制的ERF阻尼器用于缓冲隔振支座的设计中，可实现有效的振动控制，使产品在运输过程中不会由于振劝冲击而损坏，经仿真模拟缓冲隔振效果明显。     

AAL层抗信元丢失技术

ＡＴＭ网络中传输视频信号存在的信元丢失会严重影响接收图象的质量，可以从视频编解码端与ＡＴＭ适配层采取抗信元丢失技术以减少该影响。不同ＡＡＬ有不同的抗信元丢失原理。本文分别对用ＡＡＬ１，ＡＡＬ２，ＡＡＬ５适配ＭＰＥＧ－２视频信号时在ＡＡＬ层采取的抗信元丢失技术进行了分析。     

全断面掘进机(TBM)刀盘总推进力的分析计算

探讨了在不同的地质条件下TBM刀盘总推进力的设计计算方法,有利于优化TBM的结构参数和总装机功率,提高TBM适应不同地质条件的能力,并以ROBBINS(美)公司MB264-311型TBM为例进行了模拟计算,证明该计算方法正确有效。     

军械调运方案优化算法的设计与仿真

军械调运问题的数学模型和手工算法过去已有研究,但是当问题较为复杂时,手工算法就要花费大量时间而且准确性也难以保证。针对这一缺陷,本文在已有的数学模型和手工算法的基础上,设计了一种可以用计算机实现的基于递归的算法来寻求军械紧急调运问题的最优方案,并使用面向对象的java语言将算法实现。     

黑龙江化肥厂锅炉房用煤车、贮存、运输方案的优化设计

通过对原可行性研究报告中的锅炉房用煤采用筒仓群贮存方案的了解、分析、比较后,提出了采用矩形库贮存煤的优化方案设计的成果。     

试谈铁路运输企业发展第三方物流的对策

从物流及第三方物流的概念着手,主要分析了物流与铁路运输的本质区别,并就铁路运输开展第三方物流优势及存在问题进行了详细分析,重点论述了铁路运输业开展第三方物流的可行性及有关对策。