全容式LNG储罐罐底保冷技术概述

以国内某16万m3LNG大型储罐为例,对罐底保冷系统的结构特点、施工顺序、安装技术等内容进行了叙述。     

LNG低温储罐罐壁保冷施工技术研究

罐壁保冷施工技术是LNG低温储罐保冷使用的重点,其具有结构设计复杂、安装标准高以及高空作业多等特征,施工难度较大,要求施工人员在对储罐进行施工时,做好相应的质量管控,严格依照相关规范及标准开展施工作业,保障施工的效率和安全。从结构特点、施工顺序和施工方法等方面,对LNG低温储罐罐壁保冷施工技术进行了分析和探究。     

30000 m~3单容双壁LNG储罐施工技术

LNG储罐作为LNG的陆上储存设备,属常压、低温大型储罐,通常为平底、双壁圆柱形,主要分为单容罐、双容罐及全容罐。单容式储罐投资相对较低、施工周期短,但容易泄漏,其制作、安装技术显得尤为重要。现以湖北某5×10~6m~3/d LNG工厂国产化示范工程30 000 m~3LNG储罐为例,从储罐的结构、安装、焊接、保冷、水压/气压试验等方面对其施工技术进行阐述。     

160000m3LNG储罐保冷性能研究

计算了福建160000m3 LNG储罐罐底、罐壁和罐顶的漏热量,根据储罐的日蒸发率估算了储罐的许用漏热量。通过对比计算储罐漏热总量和许用漏热量,分析了储罐的保冷性能。所做的研究对于大型低温设备的设计、研究和工程应用具有一定的参考价值。     

全容式LNG储罐漏热量模拟分析

本文以某160000 m3全容式LNG储罐为例,介绍了全容式LNG储罐保冷方式的基本构成。通过大型分析软件workbench模拟了罐体各部分热量的传递,分析表明在正常工作情况下外罐与罐底交汇处热流量最大。提出对漏热量较大的外罐与罐底交汇处区域进行增加保冷层厚度、改良保冷材料等措施的优化方案。模拟结果可为工程实践提供参考。     

大型液氨储罐设计要点

以设计实例分析大型低温储罐罐型、设计标准、设计理念,介绍地上单包容双壁圆筒形金属低温储罐的结构、内罐、外罐和保冷结构等设计要点。     

浅谈大型低温储罐的设计

本文旨在对大型低温储罐的设计进行研究,以大型低温液化气储罐的设计为例,具体介绍了了液化气的存储方式;并探讨了低温常压存储设备的设计选材,主要包括了钢材以及保冷选材等等;接着研究了保温层的结构设计,包括了罐顶的结构设计、罐壁结构设计、罐底的结构设计;最后,分析了储罐的基础设计,具有一定的现实意义。     

5000 m3常压低温液氨储槽安装过程中质量控制要点

安阳化学工业集团有限责任公司5 000 m³常压低温液氨储槽安装项目,由于低温特点对材料性能要求高,安装要求标准高,重点对施工过程中的预制过程、组装过程、焊接过程、储罐保冷、储罐几何检查的控制要点进行分析,以及对充水实验质量控制过程中的要点进行重点关注和预检,以保证安装质量。     

低温储罐现场主体安装工艺

目前国内外在大型储罐建造中主要以原油储罐为主,而大型低温储罐的建造较少,我们通常所指的低温罐是以公称容积大于或等于10000m3,设计温度不高于-45℃且不低于-168℃的立式圆筒形低温储罐。低温钢对主体安装工艺的要求非常严格,特别是对于施工工序及安装顺序的要求,因此如何控制施工程序,制定出合理的主体安装工艺将是研究中的重点内容。     

LNG储罐漏热与影响因素分析

利用ANSYS对大型全容式LNG储罐罐顶、罐壁、罐底3部分建模,进行温度场数值模拟。通过与现场检测数据对比表明,储罐温度场分布情况与实测结果相吻合。模拟结果表明罐底的绝热性能最差,需要对罐底保冷层进行优化设计。同时对比分析了不同环境温度与风速对储罐各部位漏热量的影响,得到环境温度变化对罐壁漏热量影响较大;风速变化对储罐整体漏热量影响较小,仅对储罐罐顶漏热量影响较大。     

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.     

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。     

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.