大容量真空断路器的应用及经济运行分析

介绍了发电机断路器的选择原则，通过对少油断路器，六氟化硫断路器，真空断路器的技术分析和经济比较，选择了合适的断路器。     

发电机断路器的经济选择及运行的经济分析

发电机断路器选择的原则要遵循既能满足技术条件、环境条件和运行维护，又要进行技术经济比较。我们在选择时充分遵循上述原则，通过对少油断路器、六氟化硫断路器、真空断路器的技术分析和经济比较，选择了合适的断路器。     

粉末冶金触头材料的显微组织对高压SF6断路器开断性能的影响

本文对分别采用熔融浸溃法、预烧钨骨架熔融浸溃法及冷等静压预烧钨骨架熔融浸溃法三种工艺制造的铜钨80、铜钨70和钨铜氧化镁电触头材料,通过在高压六氟化硫断路器灭弧室相似模型上,利用斜波电流回路进行开断试验,观察其开断试验前后显微组织的变化及烧损情况,从而比较出不同触头材料的显微组织对六氟化硫断路器开断性能的影响。其中用铜钨80、预烧钨骨架熔融浸溃法工艺制造的触头材料,在六氟化硫气体介质中开断性能及耐烧损性能优于其它几种触头材料。     

使用GIS的优越性

所谓GIS,就是六氟化硫(SF6)全封闭组合电器。它是将刀闸、开关、电流互感器、电压互感器等电气设备组装后,全部封闭在一个接地的金属外壳内,其内充以294～392kPa压力的六氟化硫气体,从而保证设备的相间绝缘和对地绝缘。 南京供电局110kV西华门变电站引进的日本SF6;封闭组合电器,1986年投运,使用至今,实践证明具有以下优越性: 1.占地面积小,安装操作简便。该变电站原为城区的35kV变电站,在市区人口密集的主干道旁边,升压改造为110kV变电站后,面积无法扩大。一般采用全封闭组合电器的变电站的占地面积,仅为敞开式变电站的1/5。SF6断路器…     

SF_6断路器气体压力异常在线监测系统改造

介绍了一种SF_6断路器气体压力异常在线监测系统,通过实施SF_6断路器气体压力监测技术改造,实现了对SF_6断路器气体压力的实时监测,确保SF_6断路器的安全可靠运行。     

新牵引变电所1#进线柜断路器线圈烧损分析

白云铁矿新牵引变电所负责全矿的直流系统供电,将6 000 V的交流电经整流变为直流1 500 V,给全矿的铁路生产系统供电。现对其进行升级改造,在改造期间,进行空线路试送电的过程中,发生断路器线圈烧损情况。根据断路器烧损现象,分析断路器线圈烧损原因,提出防止断路器线圈烧损的保护电路。     

应用真空断路器改造老式开关柜

鞍钢有许多ＧＧ—ＩＡ老式开关柜，其贫油断路器在分断频繁的场合下使用，供电事故率高，检修费用大。为此，采用真空断路器替代了老式贫油断路器以改造旧开关柜，取得了较好的经济效益。     

安钢23500Nm~3/h制氧机组配电高压控制回路的改造

通过对高压断路器的控制原理图和其外部电气原理图的分析,找到了高压真空断路器合闸后无故自动跳闸故障的原因,并对其外部电气回路进行改造,解决了这一问题,为设备的安全稳定运行提供了保障。     

一种改造老GG—1A开关柜技术问世

鞍钢矿山动力厂研究的应用普及型真空断路器改造老GG—1A柜技术问世并通过市级鉴定。 该成果适用于10kv及以下电力系统的老开关柜改造,尤其适用于矿山系统的高压开关柜改造。该技术自1986年研究成功以来,先后在鞍钢等地改造老GG—1A柜200余台,创效益达240余万元。专家们认为,应用该技术改造的开关柜各项性能指标均达国家标准,防震、机械传动及防止误操作等措施处于国内同行业领先地位。     

鞍钢供电厂手车式断路器的改造

鞍钢供电厂早期安装投运的手车式断路器，主要为SN１０－１０和ZH４－１０两种型号，配以电磁操作机构，经过二十多年运行，存在一些无法消除的隐患，需予以改造。结合国内外中压断路器的无油化发展状况———在１２kV及以下电压等级，真空断路器应用发展迅速，现选取国内比较成型的产品ZN１２－１２真空断路器，配以弹簧操作机构作一介绍。１ZN４－１０和SN１０－１０断路器存在的问题１．１ZN４－１０存在的问题ZN４－１０断路器为真空开关的早期产品，受当时的触头材料及加工工艺所限，存在不少缺陷：（１）由于触头材料的性能，加…     

六氟化钨净化工艺研究

工业制备的初级六氟化钨含有大量杂质气体和金属杂质,必须进行净化,其过程首先采用化学试剂置换去除杂质气体中沸点与六氟化钨接近的氟化氢,然后将反应后的六氟化钨蒸馏至精馏釜中进行低温固化,再利用真空系统抽真空排出其他杂质气体,初步净化后的六氟化钨检测合格,可直接进行精馏去除金属杂质。经过多步净化后,成品六氟化钨的纯度可达99.999%以上。     

高纯六氟化钨制备工艺研究

介绍了利用氟气与钨粉为原料制备高纯六氟化钨的工艺方法和设备体系。其过程是利用电解槽电解氟氢化钾制取氟气,并采用氟化钠吸附配合深冷工艺纯化氟气,净化后的氟气与固定床里的钨粉在一定温度条件下反应合成初级六氟化钨,通过低温冷凝回收,收集的初级六氟化钨经过固化后抽真空排轻等方法进行初步提纯,然后将初步提纯的产品蒸馏至填料式精馏塔内进行深度提纯,经过多步提纯后的成品六氟化钨纯度可达99.999%以上。     

Visually discernible myocardial echocardiographic contrast after intravenous injection of sonicated dextrose albumin microbubbles containing high molecular weight, less soluble gases

OBJECTIVES: The central hypothesis of this study was that microbubble survival, and subsequent left ventricular and myocardial ultrasound contrast, could be improved by altering microbubble gas to consist of a higher molecular weight (less diffusible) and less soluble gas. BACKGROUND: Microbubble survival after intravenous injection is shortened because of rapid diffusion of blood-soluble room air gases (nitrogen and oxygen) across the permeable bubble membrane into blood. METHODS: Thirteen open chest dogs received intravenous injections of a constant dose of sonicated dextrose albumin that was incubated with either room air or 100% nitrogen, 100% helium or 100% sulfur hexafluoride. Nitrogen (100%) is less blood soluble than room air, whereas helium and sulfur hexafluoride are the least soluble. Sulfur hexafluoride has the slowest diffusion rate. To further decrease the diffusion rate, each sample was administered during inhalation of room air and again during brief inhalation of the same gas with which it had been incubated. RESULTS: The highest peak videointensity in the left ventricular cavity was produced by the sonicated dextrose albumin incubated with sulfur hexafluoride, the gas having lowest blood solubility and diffusion rate, while sulfur hexafluoride was briefly inhaled during the period of intravenous injection (peak videointensity 139 +/- 10 vs. 54 +/- 11 for room air-exposed sonicated dextrose albumin, p < 0.001). Myocardial contrast was visually evident in > 80% of the intravenous injections of sulfur hexafluoride-exposed sonicated dextrose albumin when the agent was given as an 8-fold concentrated sample during brief inhalation of sulfur hexafluoride. CONCLUSIONS: Visual myocardial echocardiographic contrast is possible after intravenous injection of sonicated dextrose albumin if the microbubbles contain a gas with low blood solubility and diffusivity.     

Toxic shock syndrome after mastoidectomy

PURPOSE: To evaluate the effect of topical aqueous humor suppressants on the absorption of intravitreal perfluorocarbon gases. METHODS: Sulfur hexafluoride or perfluoropropane was injected intravitreally in five rabbits. Time to gas disappearance was measured in eyes treated with topical aqueous humor suppressants and in those not treated. RESULTS: The mean time (+/- SD) to disappearance of 0.4 cc of sulfur hexafluoride was 5.6 +/- 0.9 days, which was prolonged by 43% to 8.0 +/- 0.7 days with topical aqueous humor suppressants (P = .009). The mean time (+/- SD) to disappearance of 0.2 cc of perfluoropropane was 18.4 +/- 1.9 days, which was prolonged by 55% to 28.6 +/- 2.7 days with topical aqueous humor suppressants (P = .009). CONCLUSION: Aqueous suppressants prolong sulfur hexafluoride and perfluoropropane intravitreal gas bubble duration in rabbits.     

低压断路器的种类与选择

介绍了热断路器、磁断路器和漏电断路器等几种目前常见的断路器,并介绍了如何根据周围环境特征、电流种类、电压大小、保护要求等条件进行选择。     

Comparison of grinding kinetics between a typical ball mill and a ball mill fitted with a breaker plate

A ball mill with a breaker plate and a similarly sized typical ball mill without a breaker plate were studied in order to determine if the breaker plate can improve mill grinding efficiency. At hypocritical frequencies of rotation, it was found that the ball mill with the breaker plate grinds more efficiently, and especially so for particles larger than 1 mm. The breakage function for the ball mill with the breaker plate was found to be non-normalized, while that for the ball mill without the breaker plate was close to normalized. First-order kinetics was followed by both mills.     

大型预焙铝电解槽打壳系统的改进

通过对铝电解槽打壳系统的研究和改进,设计制作了新型密封性打壳系统,减少了打壳气缸故障,减少了锤头粘连,解决了下料不通畅的问题,提高了生产效率。     

正确理解和选择低压断路器的电流参数

分析低压断路器的各个电流参数的概念、俗称及其作用,帮助从事电气设计、采购、施工和监理工作人员正确理解断路器参数的意义和确定参数,并提出选择低压断路器时就标定的电流参数和标定方法。     

真空断路器在大电炉上的应用

涟源钢铁集团有限公司一炼钢厂１~＃、 ２~＃６０ｔ电炉 ２０ＫＶ高压断路器由原法国二手压缩空气断路器改为国产真空断路器的设计过程及改后经济效益的分析。     

颚式破碎机动力学计算机分析及相关零件CAD

建立复摆颚式破碎机动力学计算的数学模型，在此基础上，完成了复摆颚式破碎机动力学零部件CAD程序设计．应用结果表明：该CAD程序完全适用于颚式破碎机的工程设计计算，并且设计内容丰富，计算结果精确可靠，效率高．