抽油机采油井筒内气液分离器数值模拟研究

提出一种将抽油机井气液分离器入口进液量转化为脉动入口速度的方法。采用计算流体动力学方法，基于欧拉模型（Eulerian Model），针对抽油泵的工作特性和不同的含气体积分数对分离器内流场分布和分离性能影响开展数值模拟研究。数值模拟结果表明：当井下压力为8 MPa，入口含气体积分数在79.6%～90.0%范围内适当增加混合液的含气量可以提高气液分离器的分离效率。     

旋流分离器在乙二醇脱盐过程中的模拟研究

应用计算流体力学(CFD)模拟研究了旋流分离器内液固(乙二醇-NaCl)两相分离过程.应用RSS雷诺应力湍流模型、DPM离散相颗粒模型,建立液固两相分离模型,研究了旋流器结构、固相颗粒粒径、操作条件对颗粒分离效率、压降的影响.结果表明:采用优化的旋流分离器,粒径大于35μm的NaCl颗粒分离效率可以达到99.6％以上.     

基于Fluent仿真的立式分离器优化设计

油气混输一体化集成装置主要由多功能合一设备、混输泵、阀门管线、辖井数字化管理系统及橇座等组成。原油混合物通过多功能合一设备中的立式分离器,分离出伴生气为原油混合物提供加热原料,其分离效率直接影响加热效果。针对现场部分油气比较高的站场,立式分离器分离效果有限的问题,利用Fluent软件提供的离散相模型,对该立式分离器油气分离过程的流场进行了分析,并对立式分离器结构进行优化设计,通过对改进前与改进后两种结构流场的压强,速度,流线和离散项运动轨迹进行分析,并计算分离效率。结果表明,通过优化立式分离器的结构,可以改变整个立式分离器内部流体的流动方式,可以明显的提高整个结构的气液分离效率,达到了结构优化的目的。     

可用于MVR蒸发系统的气液分离器改进结构分析

针对常规气液分离器对微小液滴分离效率低的不足,提出一种可用于MVR蒸发系统的气液分离器结构,并采用数值模拟结合实验验证的方法对其分离特性进行研究。首先,利用数值模拟的方法分析了气液分离器内部流场和压力场,确定了影响分离效果最明显的位置,然后提出了在该位置加装不同数量3/4圆环形挡板的分离器结构。其次,模拟研究了此种新结构的分离效率和压降等分离特性以及挡板数量变化的影响规律。最后,通过实验验证的方法分析了数值模拟结果的可靠性和新结构的分离效果。研究结果表明：圆柱型筒体是影响分离器分离特性的关键部位,在气液分离器圆柱形筒体内部增加3/4环形挡板,能够增加物料切向运动的有效长度,降低物料的径向速度,从而显著提高微小液滴的分离效率,气液分离器整体压降却增加不多;而且随着环形挡板数量的增加,该结构气液分离器的分离效率和压降均明显提高。在本文计算条件下,加装3/4圆环形挡板的气液分离器结构,可以将直径在3 μm以下的液滴分离效率提高15%,而压降仅增加了200Pa。综合气液分离器效率和压降影响,加装两个3/4圆环形挡板的气液分离器性能最佳。     

旋流器内气液两相流动的理论分析

气-液旋流分离过程是气-液两相的三维强旋流运动。以漂移流动模型和颗粒轨迹方程为基础,采用欧拉-拉格朗日方法建立一种新的气液两相流动机理模型。该模型可以用来直接计算气液旋流分离器内部流场中连续相、分散相(液滴)的速度分布,通过计算能够预测旋流器内部的浓度分布,并通过对影响气液分离效率的主要原因——出口气体中的液滴夹带进行分析计算,预测旋流器的分离性能。     

螺旋片导流式分离器分离性能的数值模拟与试验研究

应用计算流体力学（CFD）方法对不同结构参数的螺旋片导流式气液分离器在湍流状态下的流体流动场进行了数值模拟,研究了螺旋个数和螺距对螺旋片导流式气液分离器分离性能的影响,并与试验测定结果对比,由此验证基于数值模拟方法设计螺旋片导流式气液分离器分离效率的可行性与准确性.分析结果表明,数值模拟结果与试验数据基本一致,可以作为螺旋片导流式气液分离器设计的有效工具.     

斜板式气液分离器的设计

针时常规卧式和立式气液分离器的缺点和不足,论述了斜板式气液分离器的分离机理和结构特点,提出了采用斜板结构有利于提高气液分离效率的新思路,建立了斜板式气液分离器的理论计算公式,并以常规卧式分离器和立式分离器为例进行了对比计算。结果表明斜板式气液分离器可以提高气液分离器的分离效率,即在相同结构外径与处理量的前提下,可以缩短分离器的长度。或在相同结构条件下可以降低带出液体的粒径。     

油水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油水旋流分离器的内部流场,模拟出分离器内轴向速度变化规律,得到钻井液气液旋流器内部流场的特征。分析油水旋流分离器内部油相体积浓度分布,得到了油水旋流分离器内部流场的分布规律和油水两相流的分离特性,为油水旋流分离器的工艺设计提供了参考依据。     

蒸气压缩制冷/热泵系统中的气液分离技术

蒸气压缩制冷/热泵系统利用气液相变实现热量转移,如何应用气液分离技术对两相工质进行干度调控与流量分配,保证系统运行稳定性并提高系统性能一直是研究的热点。本文综述了蒸气压缩制冷/热泵系统中气液分离技术的研究进展,总结了系统中气液分离技术的应用方式,讨论了不同应用方式中该项技术的主要功能与工作机制,并对重点研究方向进行展望。研究发现气液分离技术的主要功能有保障系统运行可靠性、提高换热器性能、对非共沸混合工质进行组分分离以及改进循环流程等,对气液分离器性能提升方面现有的研究尚有不足,计算流体动力学（CFD）仿真模拟是研究其内部分离机理和对气液分离器进行结构优化的有效方法。气液分离技术应用方式的开发、相分离换热器优化研究与气液分离器的设计优化将会成为今后研究的重点方向。     

立式天然气多管旋风分离器内流体的流动特性

利用数值模拟的方法,采用Reynolds应力输运模型和随机轨道模型,对一种立式天然气多管旋风分离内的湍流气粒两相流动进行了全尺寸的数值模拟。为了反映真实的流动过程,计算过程中对进气室、集气室、集尘室及各轴流旋风分离器等复杂结构没有进行简化,并实现了完全结构化的网格划分。结果表明,除尘器内各旋风单管的工作状态并不相同,集尘室内含尘气体在各单管间发生窜流返混,影响了多管旋风分离的分离效率;此外,计算结果还表明,适度提高泄气率有助于抑制单管间的窜流返混,为天然气立式多管旋风分离的优化设计提供了理论依据。     

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。