锥角变化对旋流除砂性能影响的数值模拟

针对在油田开展采出液除砂的必要性进行了介绍,对所研究的除砂型旋流器结构和基本原理进行了说明。利用数值模拟软件Fluent,将某油田现场采出液作为分离对象,对主直径为56mm的除砂旋流器进行变锥角结构数值模拟研究。得出不同锥角结构旋流器的速度场、压力降和砂相体积分数分布的变化规律,并对不同锥角结构旋流器的除砂分离效率进行了对比。研究表明:当锥角为5°时,旋流器内部产生的切向速度最大,底流出口砂相体积分数分布最高,但也伴随着较大的压力降,所完成的砂相分离效率最高为96.30%。     

钻井液气液旋流分离器内部流场的CFD模拟

采用计算流体力学数值模拟方法研究了钻井液气液旋流分离器的内部流场,模拟出了分离器内部的压力分布、轴向速度和切向速度的变化规律,得到了钻井液气液旋流器内部流场的特征,为钻井液气液旋流器分离器的工艺设计提供了参考依据。     

一种旋流除砂装置的数值模拟研究

介绍了油田采出液成分,阐明了采出液除砂的必要性,结合旋流分离技术与重力沉降技术,设计了一种底流封闭的单出口旋流除砂结构。利用计算流体动力学软件Fluent,计算旋流除砂器的内部流场,得到了相应的压力损失分布云图和砂相分布云图,通过对旋流除砂装置内部的旋流分离和重力沉降的模拟分析,为旋流器和储砂箱的结构优选提供了设计依据。     

多管水力除砂器内液-固两相流的数值模拟

通过数值模拟的方法,采用RSM湍流模型对多管式水力除砂器内液-固两相流场进行了研究。研究表明:进液室的流场分布、压力分布影响各单管入口流量及速度分布;除砂器内颗粒运动的轨迹包括储料室捕集和集液室逃逸;将1000个颗粒同时射入除砂器总入口,跟踪每个颗粒得到颗粒的入管比例和分离效率,单管的颗粒入管比例与流量呈正相关,单管分离效率受速度分布影响出现差异;随着颗粒粒径增大,从单管分离出的颗粒在储料罐内的沉降速度也增大;综合各单管的颗粒入管比例和分离效率对除砂器分离系统的结构提出改进方向。     

换热器气体分布器内流场分析

为了设计一个有效、符合空气动力学原理的分布器,采用苯蒸汽作为模拟介质,利用CFD软件FLUENT对换热器入口气体分布器内的流场进行了数值模拟和计算。结果表明,分布器内的压力呈马鞍型,内部高,两端低;管束入口的速度均匀,说明流体的流动得到很好的分配,分布器的周边虽然存在弱回流,但对整体流动换热影响不大。该分布器的结构可以用于工程设计与应用。     

300Mw机组容量脱硫喷淋塔内部流场模拟研究

采用Fluent软件对300 Mw机组容量的脱硫喷淋塔的内部流场进行了数值模拟,使用Gambit软件对该模型采用非结构化四面体网格进行网格划分。研究了烟气的不同的入口形式,不同的入口角度对流场的影响。结果表明:120°和180°双入口烟道,入口角度为15°斜向下时,具有较好的流场分布。     

不同操作参数下动态水力旋流器内部油水两相流动的数值模拟

根据计算流体动力学(CFD)的方法,应用Fluent软件对动态水力旋流器内部油水两相流场进行数值模拟,考察了不同入口流量及转筒转速下旋流器内速度场与油水两相的分布情况。结果表明:动态水力旋流器内切向速度呈双涡结构(准自由涡与准强制涡);轴向速度明显小于切向速度且不存在零速度包络面,油相集中于旋流器轴心形成油核,随着流量及转速的增加,各相速度及中心油核浓度均增加。     

大锥段注气对液-液水力旋流器分离性能的影响

针对油田含聚污水处理难度大的问题,利用CFD和多孔介质模型建立了旋流器内部流体的计算模型,数值模拟分析了大锥段注气旋流器内多相流体速度场和压力场的分布规律,结果表明:大锥段注气后,在旋流区和大锥段区的径向速度和流向溢流口的轴向速度明显提高,分离性能有所改善;产生的气浮选效应使混合液的分离难度降低,压力降减小,节约了能源。提出旋流器流场分界区的概念,研究表明在分界区注气能更好地改善分离效果,分界区的位置取决于旋流器的结构参数和操作参数。     

轴流式脱气除砂三相旋流分离器操作参数优选

针对一种新型轴流式脱气除砂三相旋流分离器,利用数值模拟分析软件Fluent,对旋流器进行全流场数值模拟,研究得出了旋流器内部速度分布规律、压力降特性和气相、固相体积分数分布情况,对分离器进行变处理量和分流比(溢流、侧向)操作参数的对比分析,优选得出分离器最佳分离性能下的处理量、溢流分流比和侧向分流比分别为6.4m3/h、40%和4%。     

轴流式水力旋流器的设计与数值模拟计算

基于液液两相旋流分离原理,结合水力旋流器的工作特性,采用数值模拟的方法,设计了一种入口有螺旋流道和底流口带有倒锥的轴流式旋流器。用Fluent软件模拟计算后,再分析该型旋流器典型截面的特性、油相体积分布等情况,对比传统切向入口水力旋流器,其结构更加紧凑、内部流场更加稳定而且分离效率更高。     

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。