基于PCS7液化天然气接收站的火气系统

基于西门子PCS7系统,着重从安全逻辑设计、火气系统(FGS)及软/硬件等方面设计LNG接收站火气系统,确保LNG接收站安全可靠,以满足中国广东珠海金湾液化天然气项目的工艺要求,为其他LNG接收站控制系统的安全设计提供参考。     

LNG集液池排液系统研究

LNG集液池用于收集事故工况下泄漏的LNG,是保证LNG接收站安全的重要组成部分,LNG和水接触会发生爆沸,因而需要设置排液系统将集液池内的雨水及时排除.本文以某LNG接收站项目为例,对LNG集液池排液系统进行研究,对排液泵参数、管道参数、排液泵类型、控制系统进行设计.     

LNG脱酸系统发泡原因分析与处理

通过对宁夏哈纳斯LNG装置试车期间脱酸系统发泡事故操作参数进行研究和对发泡胺液、原料气取样化验分析,根据所得发泡成因,采取一系列相应的措施,有效解决了胺液发泡事故的再次发生,为LNG生产装置脱酸系统发泡问题的原因分析和处理方法提供了宝贵的经验。     

天然气处理厂火气报警系统的研究与应用

苏里格第四天然气处理厂火气报警系统(简称FGS站)自动采集各个区域的可燃气体探测器、火焰探测器的输出信号和手动防爆火灾按钮信号,完成可燃气体泄漏浓度监测报警、火灾监视报警和声光报警。FGS系统与PCS系统进行数据连接,建立动态数据库。当有报警信号时,能准确地切换到相应画面,显示出报警部位,同时FGS系统向ESD系统发出火灾报警信号,ESD系统做相应的紧急停车控制。FGS系统采用UPS供电,采用冗余控制器完成数据采集、处理和控制;FGS系统设置工程师站/服务器/操作员站,完成组态和实时监视。     

LNG点供站在城市燃气事故应急供气系统的使用

本文简要介绍应急事故或者调峰阶段运用的备用气源类型,重点探讨LNG点供站系统运行特点,对于燃气事故的备用气源设施方面存在的问题进行简要分析,进而提出事故发生阶段LNG点供站备用气源的应用策略,以供参考.     

基于贝叶斯网络的LNG储罐泄漏事故树改进研究

通过对LNG储罐泄漏事故树模型进行分析,得到LNG储罐泄漏事故树的最小割集与结构重要度,确定了LNG储罐泄漏失效系统中的薄弱环节。同时由于LNG储罐的泄漏原因复杂性,而事故树中事件只有正常和失效两态,与工程实际不相符,使得事故树在应用于LNG储罐泄漏原因分析中受到了限制。为了能够提高LNG储罐安全失效分析的准确性,通过贝叶斯网络对LNG储罐事故树的二态性进行了修正。结果表明,修正后的贝叶斯网络模型更加符合工程实际。     

LNG储罐罐表系统设计

液化天然气(Liquefied Natural Gas, LNG)的主要成分是甲烷，是地球上最清洁的化石能源，液化天然气主要的存储方式是LNG储罐，是液化天然气工业中的核心设备，因此LNG储罐的安全是工厂安全运营的重中之重。其中LNG储罐中容易发生“翻滚”的现象，因为储罐内液化天然气的大量蒸发进而引发非常严重的事故，所以需要预防和消除“翻滚”现象。因此可通过对LNG储罐设置罐表系统，来检测储罐的温度、压力、液位及防止储罐“翻滚”等，并设置泄漏报警系统、消防灭火系统、可燃有毒报警系统，保障储罐的安全稳定运行。本论文主要研究和设计了罐表系统组成及防“翻滚”系统，为罐表系统在LNG储罐中安全运营及管理提供指导。     

LNG接收站LNG储罐泄漏收集系统

LNG储罐泄漏收集处理系统是LNG接收站工艺安全中非常重要的一部分,特别是青岛输油管道爆炸事故发生后,更应重视LNG泄漏收集处理系统的设计。本文对LNG储罐罐顶泄漏收集处理系统的主要技术参数进行了研究,包括LNG收集区域围堰高度,雨水分离池原理,LNG收集池尺寸,结合实际工程案例,在理论上进行了总结与提高,研究结果对于同类LNG接收站的LNG储罐泄漏收集处理系统的设计和配置,能起到一定的指导和借鉴作用。     

浅谈LNG工厂仪表风多联供应保障系统的优化方案

LNG是液化天然气的英语缩写,LNG生产中需要应用仪表风系统来调节气动阀门。如果仪表风系统能稳定的动行,它就能高效的指挥LNG系统动作,起到上传下达的作用;反之,LNG系统不仅会产生故障,而且还有可能爆发非常严重的工程事故。介绍了一套LNG工厂仪表风多联供应保障系统的优化方案。     

LNG储罐消防设计探讨

根据LNG的火灾危险性和LNG全容罐储罐的设置型式,对储罐发生事故时各个危险场所的火灾性质进行分析,介绍了LNG储罐在罐顶各个操作平台、事故液集液池、安全泄放阀处应采取的相应消防设施情况,并对其水喷雾冷却系统、高倍数泡沫混合液系统、干粉灭火系统的设置原则、目的、计算过程及注意事项进行了阐述。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.