长输天然气管道项目风险分析与管理措施

近几十年来,全球长输天然气管道建设进入了一个高峰期,各种新材料、新设备和新技术的应用,使长输天然气管道设计、施工、运营管理等技术取得了很大的发展,尤其是大口径、高压力的主要天然气管道建设和运营管理技术发展更快。我们应该不断坚持技术进步,不断提高施工质量,不断提高项目管理的质量水平,从而提高长输管道建设新工艺技术的应用,为我国的管道工业做出贡献。本文从长输天然气管道项目建设的特点出发,结合长输天然气的管道存在的风险,对如何做好长输天然气管道项目建设管理做了有关论述。     

浅析工程材料对长输管道施工质量的影响及措施

自改革开放以来,我国国民经济取得了举世瞩目的辉煌成就。先后建成了西气东输天然气管道、陕京二线天然气管道、兰（州）一郑（州）一长（沙）成品油管道等长距离,高压力,大口径的长输管道项目;包括在建的西气东输三线工程也在热火朝天的建设中。长输管道正在飞速的发展过程中,进而石油工业化的发展也日趋加快。与空运,铁路运输、公路运输等方式相比较,管道运输最经济适用并便于管理。但在管道工程建设周期长,造价高,资源投入多,施工难度大,各种风险因素多。因此加强长输管道在施工过程中存在的问题不容忽视。下面,我们就针对长输管道施工中注意的问题展开讨论,并对整改方案进行探究。     

浅谈天然气长距离输送管道施工过程中的风险控制和应对措施

伴随着我国经济社会的快速发展,国内的能源结构也正在经历着一场前所未有的变革,原来国内的以石油化石燃料为主的局面将会被打破,转而变成以天然气等清洁能源为主,这样会进而促进天然气长输管道工程在各方面的飞速发展与进步。所以对于天然气长输管道来说,对其安全运行的保障的研究十分重要,具有极为关键的现实意义。本文首先介绍了天然气长输管道中存在问题,然后介绍了长输管道施工特点,随后着重介绍了天然气长输管道安全施工措施,最后得出结论。     

长输管道穿越施工技术

随着我国石油天然气工业的迅速发展,长输管道在石油天然气的运输中发挥着越来越大的作用。针对管道敷设技术中的难点问题-穿越技术,结合长输管线的施工经验,从技术分类、原理、特点和主要技术措施等几方面进行详尽的介绍,其操作性强,对穿越施工有指导作用。     

探讨长输油气管道的焊接技术

随着世界经济的快速增长,石油、天然气的开采也得到了迅猛发展,导致长管道油气运输成为关系国家经济运行的重要因素,而焊接技术正是长输管道建设中的关键技术。本文根据长输管道焊接的特点和要求,阐述了常用长输管道现场焊接技术方法,并对不同焊接技术的应用前景进行了展望。     

长输管线连头及“金口”焊接引起的思考

笔者在参加川气东送的天然气长输管线的管道检测,分析长输管道的连头及“金口”焊接中出现裂纹原因,提出解决在长输管道施工最后连头焊口焊接的具体措施,经现场施工验证,该措施较好的解决问题,保证了长输管线的施工质量。     

关于天然气长输管道防腐蚀技术的探讨

天然气管道有很多种输送方式,但是使用最多的是长输管道。长输管道防腐蚀工作的好坏程度直接关系到天然气输送的安全性和可靠性以及天然气输送管道的使用寿命。因此,做好加强天然气管道防腐蚀工作是至关重要的,它关乎着企业的利益、人民群众的安全和社会的稳定。为确保天然气管道的防腐蚀工作卓有成效,我们需要从源头和基础的开始,例如,管道的设计、母材的选取、施工、运行等,以及要做好平时的管道腐蚀的相关的原因的具体分析和实际修复改善工作,长输管道的防腐蚀保护是一项系统的工程,需要结合现场实际情况进行综合考虑。天然气的使用使人们的生活发生了翻天覆地的变化,伴随着天然气长输管道防腐蚀技术的每一次创新发展,都会使社会"吃惊",可以这样说防腐蚀技术已经成为推动天然气管输行业发展的重要动力。本文基于长输管道防腐蚀技术创新的重要性的研究,将对影响天然气长输管道防腐蚀技术发展的因素以及如何更好地进行技术创新进行简单的探讨。     

浅析天然气管道焊接技术研究

随着气田的进一步开发，西气东输项目的全面启动，天然气作为一种洁净能源逐步替代传统的人工煤气，其热值高、成本小、污染少，可广泛用作城市燃气和火力发电：又因天然气碳氢含量高，也是一种优质的化工原料。在长输管道施工过程中，其焊接质量直接影响到长输管道的安全运行和使用寿命。     

关于石油天然气长输管道监控智能报警系统的研究

石油天然气是国民经济发展的必不可少的能源,而石油天然气的输送管道则是经济支柱的命脉,一旦出现穿孔以及破裂等问题和故障将造成难以预计的损失,同时还将严重影响能源输送沿线的环境,但由于常输管道常常处于较为偏远的地带,由此对相应管道的监控成为了难题。通过对石油天然气长输管道智能报警系统的基本设计理念的分析,明确了相应管道系统报警系统的设计要求,而后针对长输管道的硬件架构和软件架构的分析,实现了石油天然气长输管道监控智能报警系统的设计,为长输管道的监控提供了十分有益的探索。     

天然气长输管道工程与生态环境保护

我国是石油和天然气产业在不断的发展,随之对于天然气当中的管道施工的要求也是逐渐的增高。天然气长管运输工程当中的特点是线路长、地区的跨度比较大,安装的地形地貌也千变万化,地质也有区别,所以对于管道的安装要求就会很高。而且在对于管道进行安装的过程当中还要注意沿途的生态环境,千万不能破坏。本文针对性的对天然气长输管道工程以及生态环境的保护做简要分析。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.