Filtration of liquid aerosols with a horizontal fibrous filter

The aim of this study was to determine the filtration efficiency and pressure drop in liquid aerosol capture mechanisms using a fibrous coalescent filter. The experimental set-up was designed to measure filtration efficiency and pressure drop through the filter. To avoid the gravimetric effect, the filter was placed horizontally. A series of experiments highlighted the importance of operating conditions such as filtration velocity and aerosol concentration. The results demonstrated the advantage of working at high velocities to minimise the resistance of the medium and to enhance the mass efficiency of the coalescent filter. In parallel, no effect of aerosol concentrations in the pressure drop increase was noted.     

Analysis of lightning surge propagation in wind farm

Wind power generation is expected to become more important in future distribution systems. Although several prospective reports such as IEC 61400‐24 and NREL SR‐500‐31115 indicate an insulation scheme and grounding design for lighting protection, there still seems to be too few investigations on the problems. This paper therefore discusses lightning surge analysis using a wind farm model with 2 or 10 ideal wind turbines. Changing parameters such as grounding resistance and lightning strike points, several cases were studied. As a result of the analysis using digital simulator ARENE, it is clear that the surge tends to propagate toward the end of a distribution line in a wind farm and there is the possibility of insulation accidents at the other wind turbines when lightning attacks a wind turbine. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(2): 30– 38, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20364     

Thermal Radiative Properties of Xonotlite Insulation Material

Introduction Xonotlite-type calcium silicate (6CaO?6SiO2?H2O) is synthesized porous insulation material by hydrothermal processing with quartz powder and limestone as the raw material (with CaO/ SiO2≈1:1). Compared with fire- retardant fibre, xonotlite has more excellent insulating performance, such as low thermal conductivity, environment friendly, high intension, and wide applying temperature range, which has been emphasized in recent years by many scholars and widely used in many indu…     

薄层隔热保温涂料的研制及应用

常规保温材料的研究以提高孔隙率、提高热阻、降低传导传热性能为主,但其对流传热及辐射传热较难降低。当今以传热机理改进保温材料及保温结构是重要发展方向。文章介绍了一种借鉴国外航天工业用高科技绝热涂层的技术思路,并结合国情研制成功的具有高辐射率的薄层隔热保温涂料,它可弥补常规保温材料的不足。该保温涂料以液态涂料方式存在,干燥后的涂层热阻较大,特别是热反射率高,可有效地降低辐射传热,施工方便,涂层薄,无接缝,附着力好,集防水隔热外护于一体。绝热等级为R21.1,热反射度0.79,热辐射率0.83,固含量54％,性能接近国外同类产品水平,成本仅为国外产品的1/4左右。可直接以涂层方式使用,也可与其他多孔保温材料复合构成低辐射传热结构,作为石油石化行业成品油罐及储罐的隔热保温、管道及设备的保冷及屋面隔热保温涂层使用,综合节能效益高。     

GSM技术在配电网故障自动隔离及恢复系统的应用

为了使配电网故障的隔离和恢复的通讯更加可靠、迅速、经济，设计了一种基于GSM通讯技术，借助移动通讯系统短信业务和数据业务，实现配电网故障的自动隔离与恢复的系统。该系统通过MCU采集数据，判断故障位置与故障类型，经GSM通讯模块上传主站，主站统筹全局，实现故障段的切除，非故障区的供电。阐述了系统的工作原理、硬件结构、通讯协议和软件流程。现场的实际运行情况证明数据上报通讯准确率为100％，多次模拟线路故障，根据故障点的不同，一般在2～3min内系统都能可靠的隔离故障，恢复系统。     

排气管偏置对PV型旋风分离器性能影响的研究

以Ф300mm、标准PV型旋风分离器为基准模型进行冷态对比实验，研究了排气管与筒体轴线偏心布置对PV型旋风分离器分离性能的影响。结果表明，排气管偏置是进一步提高PV型旋风分离器性能的有效措施之一。在适当的偏心矩和偏置方位下，不仅能降低压降，还可以显著提高分离效率。     

The method of testing of XLPE cable insulation resistance to partial discharges and electrical treeing

The paper gives a method of model XLPE medium voltage cable insulation testing for partial discharges and electrical treeing with a point to plane test geometry. Based on this method, a comparative estimate of insulation resistance to treeing and partial discharges have been made. XLPE crosslinked by different methods (steam medium and hot nitrogen medium) and with varying contents of inorganic filler kaolin were tested. The characteristics of partial discharges were measured by means of a pulse height analyser characterized with a microscope. The data have been analysed statistically.     

低温导热绝缘胶粘剂研究

一种低温导热绝胶粘剂用于氢氧发动机系统表面温度传感器的端封和胶接安装，介绍了胶粘剂的技术要求，研究方案及试验结果。以DW－3超低温胶粘剂为基础，经改性设计后，仍能保持胶粘剂原有的耐低温特性，而且其导热，绝缘等性能均能满足设计和使用要求。     

多孔材料气体流量的简便计算

采用简便方法计算气体通过多孔材料的流量。当层流时，流量与压差按线性关系计算；紊流时，应按幂函数关系计算。本文提出了计算公式。     

活性碳和5A分子筛的吸附特性及其在真空获得中的作用

评述了活性碳和５Ａ分子筛的吸附等温线及其在真空佩温绝热夹层真空获得中的作用。分析了真空夹层抽真空除气时用Ｎ＿２气置换以及用“多次吸附－脱附Ｎ＿２气”方法活化吸附剂等先进工艺的机理。论述了根据吸附剂吸水的吸附等温线，合理确定活化工艺条件的方法。