回路热管微通道换热器蒸发冷却实验

采用微通道换热器作为数据中心回路热管冷却换热器,在微通道冷凝器侧进行了蒸发冷却实验。实验利用焓差平台测量了不同因素对采用蒸发冷却技术的微通道冷凝器换热影响,并分析了室内外不同温差、室外不同湿度条件下采用蒸发冷却的微通道冷凝器及蒸发器的进出口空气温差。实验结果表明：采用蒸发冷却可使冷凝器入口空气温度实现大幅温降,并增加冷凝器及蒸发器的进出口空气温度差值,喷淋后可使流经热管空气降温0.3～1.9℃,增大2%～20%的系统换热量,冷凝器换热效率得以提升,并可扩大回路热管换热器使用地区,延长回路热管年利用时间。     

R1233zd（E）高温热泵用卧式冷凝器的换热动态模拟

建立了一种R1233zd（E）卧式冷凝器的动态仿真模型,其相比于稳态模型在预测系统运行特性方面具有明显优势。详细介绍了建模所用控制方程、离散方法、运算逻辑等,模型可以计算出冷凝器在每一时间步长下,每一个控制体内制冷剂、管壁、冷却水的状态参数。由于模型涵盖了换热管的几何参数,因此改变几何参数可以模拟采用不同换热管结构对冷凝器性能的影响,比较了采用不同齿距的换热管对换热器内部相区分布、换热量、出水温度的影响。模拟结果得出,采用齿距为1.3 mm的低肋管时,出水温度较光管提升1.5℃以上,达到稳定输出的时间提前1 min以上,换热量提升2.3倍。R1233zd（E）作为新型环保工质,缺乏相关的热泵模型研究,因此搭建该冷凝器模型是完成R1233zd（E）高温热泵模型的重要基础。     

吸收式溴化锂制冷机组在工业中的使用

正1吸收式溴化锂制冷机组构造以及制冷原理吸收式溴化锂制冷机组主要由发生器、冷凝器、蒸发器、吸收器、溶液热交换器、屏蔽泵、真空抽气系统、控制系统组成。其中90%的外观部件都是由换热器组成,所以从表面上看,溴化锂制冷机组就是由多个换热器组成的一台换热设备。吸收式溴化锂制冷机组的制冷原理,简单地说就是用热制冷,具体地说就是发生器中使用热源(包括蒸汽、热水、天然气燃烧等)加热溴化锂溶液,蒸出溶液中的溶剂水,这些高     

采用R407C的热泵系统工质非完全相变及其对系统参数的影响

为了揭示热泵系统中R407C在冷凝器和蒸发器中非完全相变与系统参数的关系,首先引出了换热流体极限流量的概念,然后利用热力学循环分析的方法对R407C的非完全相变现象进行了研究,给出了影响R407C非完全相变的几种主要系统参数,如工质与换热流体之间的温差以及压缩机的排气量等,并给出了这些参数与换热流体极限流量之间的定性关系,最后又讨论了换热器内部工质的压降对该工质非完全相变的影响.     

内外双螺纹高效换热管在矿用井下制冷机组高压冷凝器中的应用实例分析

矿用井下制冷机组要求其换热器尺寸小,换热效率高,使用普通光滑换热管无法满足要求。本文针对某矿用制冷机组实际设计案例,选用内外双螺纹高效换热管为冷凝器换热管进行设计计算,使其满足工程实际需求。     

YKA圆块孔式石墨换热器

常州华东换热设备厂推出的 YKA型圆块孔式石墨换热器是目前较先进、性能优越的一种石墨换热器。其圆柱体换热块采用标准单元块 ,具有较高的结构强度 ,采用聚四氟乙烯 O形圈密封 ,并加装压力弹簧作热胀冷缩的自动补偿机构。换热器采用短通道 ,增加再分配室 ,以提高紊流效应。具有结构强度高、耐温耐压性能强、抗冲击性能好、体积利用率高、传热效率高、使用寿命长和便于检修的特点。该石墨换热器系列产品可作蒸发器、加热器、冷却器、冷凝器之用。作冷凝器用时则需底部加装气液分离器。YKA圆块孔式石墨换热器@汪焕心     

三合一塔检修小结

1三合一塔主要结构 三合一塔由上部冷凝器、氨蒸发器和下部氨分离器组成。上部冷凝器和氨蒸发器为列管式换热器,冷凝器管内和管间均走合成气,管间为液氨,靠液氨蒸发带走热量;下部氨分离器由内件（旋风分离器、折流板、丝网除沫）及外壳组成,主要起分离作用。冷凝器、氨蒸发器与氨分离器之间为法兰连接,密封形式采用双锥金属环径向自紧式密封。     

基于AMESim泵驱动两相回路热管系统的传热特性

为降低机柜的散热负荷，减小散热系统的体积和质量，并且提高冷却系统的能量利用效率，提出利用微通道平行流换热器泵驱动两相回路热管系统方案，基于AMESim软件研究质量流量、换热器风量、环境温度、冷凝器结构参数对系统换热性能的影响。研究结果表明：制冷剂质量流量过大、换热器风量过大对系统制冷量无显著影响。室外温度是系统换热性能的重要影响因素，室外温度由10℃增加至35℃时，制冷量降低了57.9%。冷凝器流程布置和扁管排布需要考虑换热性能和流动阻力之间的平衡，平行流冷凝器为3流程，扁管数目为(12,12,10)时，系统运行性能最佳。     

多效真空浓缩器系统

单效浓缩器系统,所蒸发出来的水蒸汽在水冷凝器中冷凝下来,冷凝热就此损失掉了。多效浓缩器系统,浓缩器第一段中产生的热蒸汽,不采用水冷凝器间接换热冷凝,而是用真空度较高的第二蒸发段的酸在换热器中间接换热冷凝,从而蒸发掉酸中更多的水量。因此,采用多效蒸发器将酸浓缩到要     

列管换热器仿真实训

换热器是化工生产中重要的设备之一。在生产中可用作加热器、冷却器、冷凝器、蒸发器和再沸器，应用极为广泛。由于化工生产中对换热器有不同的变化，所以换热设备也有各种形式。间壁式换热器在化工生产中应用最广，它的特点是冷、热两流体被固体金属壁面隔开，不相混合，通过问壁进行换热，此类换热器有蛇管式、夹套式、套管式及列管式．尤其以列管式应用最为广泛。     

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。