浅谈我国LNG冷能利用技术的应用与发展

LNG是液态低温液体,在气化转变过程中释放大量能量(冷能),具有很高的利用价值,随着我国经济快速发展,能源需求越来越大,LNG冷能技术的运用越来越受到人们关注,本文就我国LNG冷能利用技术应用及发展进行了分析及论述。     

我国液化天然气卫星站冷能利用潜力分析

介绍液化天然气（LNG）卫星站及国内LNG卫星站现状,对LNG卫星气化站所提供的冷能特点进行了简要地分析,并借鉴大型LNG接收站冷能利用方式,对卫星站冷能利用可开展的项目进行了分析比较,得出LNG卫星站冷能利用势在必行并提出了发展建议.     

基于AspenHYSYS的LNG冷能利用系统设计

针对现有LNG冷能利用方式存在的投资大、需要产业聚集配套的问题,提出一种梯级利用LNG冷能发电和生产液氮的系统。采用Peng-Robinson方程计算法,借助Aspen HYSYS软件对设计的LNG冷能利用系统进行模拟计算,探究了LNG总流量和流量比对系统运行过程的影响。研究结果表明:该LNG冷能利用系统运行时氮气压缩机功率、膨胀机功率、发电机功率、系统净功率和液氮产量均与LNG流量和流量比呈线性关系,并且可以采用两种调节方式应对LNG流量的变化,通过计算得出该LNG冷能利用系统的火用效率为32.5%,证明了所设计LNG冷能利用系统的合理性。     

LNG冷能利用方式及发展前景

随着我国LNG进口量的增多,LNG冷能成为一笔不可忽视的能源财富,为了促进 LNG行业的发展,节约能源,提高LNG冷能利用率,降低●损失变得尤为重要.介绍了目前国内外LNG冷能利用方式,分析了他们的特点.并简述了在已有的LNG冷能利用方法的基础上,为提高LNG冷能利用率在冷能利用方案和流程工艺上的突破.     

LNG冷能利用研究现状

我国液化天然气需求量的增长速度超过了天然气的增长速度,在进口大量LNG的同时进口了其所携带的高品质冷能,而目前对LNG冷能利用的方式太多单一,冷能利用效率较低,造成了大量冷能的浪费。因此本文对LNG冷能利用的主要方式进行了简介,并探讨了目前所存在的主要问题,提出了相关的措施。     

LNG冷能利用技术应用现状与展望

介绍了LNG冷能利用的多种方式及其利用技术研究进展,分析了LNG冷能技术的应用现状。指出提高LNG冷能利用效果的关键是开展LNG冷量的合理规划研究,以提高LNG冷能效率。而LNG冷能综合梯级利用是提高冷能利用效率的有效途径,因此也是未来LNG冷能利用技术的发展趋势。在此基础上提出制约LNG各种梯级利用方案可行性的关键因素之一是其涉及的多个行业和领域之间的相互牵制。我国LNG冷能利用应规划先行,与LNG接收站协同设计。     

LNG冷能应用及研究

中国经济持续快速发展,能源供需矛盾日益突出,随着能源尤其是电力成本大幅度增加,LNG冷能利用越来越显珍贵。文章对LNG冷能回收混合动力循环进行了分析,指出LNG冷能利用在中国具有重大的节能减排价值和经济效益,并讨论了LNG冷能的利用及进展,为LNG冷能利用日后发展奠定了一定的理论基础。     

液化天然气接收站项目选址研究

本文在论述市场、规划、安全等传统因素对接收站选址影响的同时,讨论了新形势下冷能利用、运输、加注、轻烃回收等因素对选址的影响,提出了LNG接收站选址必须注重管输和LNG加注两个市场、冷能利用等,并对相关选址进行了分析,明确了冷能利用、小船倒运、槽车运输、LNG加注、LNG组成的重要性,对以后LNG选址具有重要意义。     

浅谈利用LNG冷能的发电系统

LNG冷能发电是高效利用LNG冷能的一种形式,常用的冷能发电工艺有直接膨胀法、低温朗肯循环法、联合法、低温Brayton法和多级复合循环法,通过对几种工艺优缺点的比较,得出低温朗肯循环法在LNG冷能利用和冷回收方面优势突出,是LNG冷能发电工艺的发展趋势。     

大型LNG接收站冷能利用策略分析

本文概述了国内外大型LNG站的建设和冷能利用的发展状况，指出我国大型LNG接收站冷能利用率很低。通过对比分析，笔者认为影响大型LNG接收站内冷能利用项目开展和冷能利用率提高的原因主要是规划不完善、产业融合程度不够、技术的集成优化程度不够及政策体制不完善，并针对这些问题提出了相关的建议。最后笔者以大鹏半岛LNG为例分析了冷能利用建设的规划思路，为类似项目的开展指引方向。     

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.     

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。