降低管道燃气购销差率分析

管道燃气是指通过长输管道将天然气输送至分输站、门站,然后经过调压计量后再通过城市管网输送至用户端,管道燃气作为天然气三大气源之一,目前城市燃气使用的大多为管道燃气。     

电动调节阀自适应控制在天然气调压中的应用

天然气分输站因距离下游用户门站较近、管存较少,当下游用户用气量变化较大时,分输站调压系统跟不上用气量的变化,使得分输站出站压力变化较大,当超出安全截断阀切断压力时,输气中断,长此下去,不但降低了设备的使用寿命,增加了场站人员工作量,而且带来了较大的安全隐患。本文就天然气分输站调压系统中增加电动调节阀自适应控制进行以下浅析。     

忠武管道与西气东输二线调压系统自控方式对比分析

在天然气分输站的生产过程中,负责调节流量、压力的调压系统具有重要作用。它接受自控系统调节,控制天然气分输,通过改变调节参数调节分输的流量和压力参数,从而实现天然气输送生产过程自动化。本文通过对忠武管道分输站调压撬的自控系统调节方式与西气东输二线的自控系统运作原理、网络结构、程序逻辑等进行分析,比较出两种自控调节方式的异同。     

浅谈天然气长输管道分输站场设计

天然气在分输站场中需要经过计量、分离以及调压等一系列的过程,因此,分输站场的设计工作极为重要,对天然气长输管道进行布置时,必须要满足《石油天然气工程设计防火规范(GB50183)》的有关规定,以现场情况为出发点,遵循相关的规范标准,根据地形情况选择科学合理的工艺流程,在设备的选择上,应该根据运行工况与检修需求进行选择。     

天然气长输管道分输站场的设计

由于经济发展与市场变革,天然气在日常生活和工业生产中发挥着重要的作用,而分输站场则是天然气输送的关键媒介,属于过渡性场所,主要功能是储存过滤和计量调压,保障着整个运输过程的安全稳定。在设计天然气分输站场要秉承科学规范的原则,以长输管道为中心点,合理配置系统功能,优化平面布置及设备,构建一体化的站场结构,确保日常供给。     

压缩天然气加气母站工艺设计方案

随着经济的飞速发展,空气质量存在着严重的问题,而清洁能源天然气是当前最合适的汽车替代燃料。应用分输站或城镇管网预留接口的天然气,经调压、计量、脱水干燥后进入压缩机,经压缩机增压至20 MPa后直接为高压气体半挂车充气,为CNG加气子站提供天然气气源,在一定程度上缓解了环境污染问题。阐述了压缩天然气加气母站的主工艺流程、安全泄压保护流程、加臭流程,压缩机、脱水装置等主要设备的选型以及自控仪表等方面的工艺设计方案。     

天然气长输管道输差分析探讨

天然气流量是天然气管道输送供应中的主要参数之一,也是天然气企业经济分析论证的主要依据,同时也反映天然气公司长输管道和分输站的运行现状。本文结合公司长输管道计量输差3%左右的情况下,通过剖析现状,分析原因,从而采取有效管控措施,降低公司长输管道计量输差,使输差在规范合理范围内。希望能对公司管理计量输差有所裨益。     

天然气分输站的运行管理措施

天然气分输站的运行过程中,必须满足输气的能力,将天然气分输给各个不同的分支管道系统,满足不同用户的需要。加强对天然气分输站的管理,提高天然气分输站的安全性,达到预期的作用效果。降低天然气分输站的安全事故的发生率,相应地降低天然气集输的成本,满足天然气生产企业的经济要求。     

煤制天然气项目长输管线计量调压系统简述

对阜新煤制天然气项目长输管线计量调压系统进行了简要的论述,内容涉及系统的功能和特点、关键设备的选型和说明。     

基于多状态的天然气长输管道分输站功能可靠性评价方法

确保分输站功能可靠是保障天然气长输管道正常供气的基础,目前尚未发现针对天然气长输管道分输站功能可靠性的定义与评价方法。目前针对油气站场的可靠性方法一般基于"二态假设",一定程度上与实际情况不符。基于此,本文根据实际情况,定义了天然气长输管道分输站的功能可靠性;应用多状态系统可靠性评价方法,提出了分输站的功能可靠性评价方法,构建了其功能风险分析模型。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.     

实施水泵节能技改 实现节能降耗

介绍了内蒙古亿利化学工业有限公司在满足生产的前提下,对现有的循环水泵实施的节能技改及效果。     

泡沫起泡性、稳定性及评价方法

本文论述了泡沫的两个基本性质:起泡性和稳定性。对起泡性和提高泡沫稳定性的方法作了评价。