35kV冷缩电缆头的制作

结合江苏斯尔邦石化有限公司醇基多联产项目一期公用工程的施工,介绍35k V冷缩电缆头制作中常见问题的处理方法及制作程序。     

10 kV电缆头绝缘击穿事故原因及防范措施

对3起典型10 kV电缆头绝缘击穿事故原因进行了深入剖析,并制定了全面、合理的防范措施,对氯碱企业10 kV系统电力电缆的隐患排查整改和安全运行提供参考。     

单芯电缆三相电压不平衡原因及处理

<正>1事情起因2007年12月7日6点5分,义煤集团水泥公司专用110kV变电站(渑池电业局管理的徐庄110kV变电站)监控系统发现10kV系统母线有小电流接地信号,相电压严重不平衡,立即把水泥公司徐处线电源拉掉(变电所供引出四个回路,分别是:徐处线,徐窑线、徐水线     

稀油站压力表及齿轮泵频繁损坏的原因分析

我公司2台球磨机共配8台稀油站,稀油站压力控制方式如图1所示。使用5年以来,8台稀油站均存在频繁损坏压力表和齿轮油泵的现象。刚开始技术人员认为是压力表的量程小和润滑油的杂质多所致,     

高压锅炉给水泵止推轴承损坏原因分析与处理

针对塔西南化肥厂合成氨装置高压锅炉给水泵在试机过程中发生止推轴承损坏的问题,采用事故树方法分析了事故原因,提出了相应的解决措施。     

变频器故障原因分析

为了解决变频器发生故障的问题,采用相关技术手段监测变频器的运行情况并根据监测数据分析了故障原因,最终提出故障改进建议.     

水泥磨主电机两次跳停的原因及处理

水泥磨主电机(YRKK1000-8,3550kW,10kV)定子温度自2003年投运以来一直偏高。2009年5月,在运行中因转子星形连接点开焊,引起一段过流保护跳停,焊接修复后运转4h,转子负载端铁芯端部压铁松动脱落,发生破坏性事故,导致定子、转子接地。分析故障原因,并根据实际情况,制定大修方案,修复后运行效果良好。     

10kV配电线路故障原因的分析及预防

本文通过对乌兰察布电业局集宁供电分局10kV配电线路故障原因的分析、探讨,结合运行环境,寻求运行规律,探索防范故障的措施,以提高10kV配电线路的安全运行水平。     

保温对地热单井换热性能的影响分析

建立了单井地热传热数学模型,模拟了单井地热流动换热过程,比较分析了不同保温材料及保温深度对采出水温度和取热功率的影响。结果表明：保温材料热导率和保温深度对系统取热功率有很大影响。当保温材料热导率为0.03 W/( m·K)和0.5 W/( m·K)时,平均取热功率分别 为732.08 kW和640.98 kW;采用热导率为0.03 W/( m·K)的保温材料,保温深度1000 m时流体进出口温差为10.33 K,保温深度为2000 m时流体进出口温差为15.98 K,保温深度为3000 m 时流体进出口温差为17.93 K。实际工程中,可以采用各种材料组合安装的形式对采出井进行保温,保温重点为井深较小处,这样既能保证采出水温,又能节约成本。     

Chemometric solid-state C NMR analysis of morphology and dynamics in irradiated crosslinked polyolefin cable insulation

The relative concentrations and carbon spin-lattice relaxation constants (T_1,C) of the amorphous, intermediate, and crystalline phases of unaged crosslinked polyolefin cable insulation (ultimate elongation, e=310%), ⁶⁰Co γ-irradiated (e=22%), and irradiated+annealed (e=220%) samples were determined by chemometric analyses of directly polarized solid-state ¹³C NMR spectra. The T_1,C relaxation curves of the intermediate and amorphous components were found to be mono-exponential. The intermediate component contains 23±5% of the CH₂ segments in the unaged sample and has an T_1,C relaxation constant of 1.4±0.3 s. γ-Irradiation caused a slight decrease in the amount of intermediate component to 19±5% and an increase of the relaxation constant to 1.8±0.3 s. The subsequent annealing of the irradiated sample resulted in an additional increase of the relaxation constant to 2.1 s and a slight loss of crystallinity. The amorphous T_1,C relaxation constants were found to be identical in all three samples and have a value of 0.38±0.03 s. At ambient temperature, the crystalline phase was found to relax via chain diffusion from the intermediate component. The rate of helical jumps was twice as fast in the irradiated and irradiated+annealed samples compared with the unaged material.     

Ultraviolet radiation aging impact on physicochemical properties of crosslinked polyethylene cable insulation

This article deals within the study of the effect of artificial radiations on physical and chemical properties of the crosslinked polyethylene (XLPE) material, widely used for manufacturing high-voltage cables. Within this framework, several experimental tests, using essential characterization techniques, were performed to study XLPE behavior under ultraviolet (UV) aging. Attenuated total reflection Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy were thus carried out to identify the main structure changes of the material before and after exposure to UV. In addition, appearance changes and DC (Direct Current) volume resistivity were evaluated. The obtained results showed that UV radiation has a great effect on the physicochemical properties of XLPE cable insulation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48575.     

35 kV和110 kV电源在电石炉的应用比较

通过供电装置及线路布置、对生产操作的影响、消耗及成本等方面的比较,讨论了电石炉分别采用35kV和110kV电源的优劣性。结果认为,在投资、安全、稳定运行、平面布置、操作难度等方面,35kV电源有优势;但在消耗、电成本方面,110kV电源有优势。从经济效益出发,建议采用110kV电源。     

基于有限元方法的单搭接接头可靠性设计

将概率统计的设计观念引入单搭接粘接接头,通过有限元分析方法分析了对粘接接头力学性能影响较大的因素,并在抽样100次的情况下,分析了单搭接粘接接头失效的概率。结果表明,该模型可以有效地反映接头的实际情况,为粘接结构的可靠度设计提供了依据。     

Effect of silane‐grafting on water tree resistance of XLPE cable insulation

Water treeing is one of the main deterioration phenomena observed in the polymeric insulation of extruded crosslinked polyethylene (XLPE) cables, which can affect the service life of power cables. In this work, we investigated the effect of grafting of a silane (vinyl trimethoxysilane, VTMS) on the resistance of XLPE to water treeing. A series of water‐treeing tests, the mechanical and dielectric measurements indicated that the silane‐grafting could significantly improve the water tree resistance of the conventional XLPE cable insulation with little influences on its dielectric properties, e.g., the dielectric breakdown strength, dielectric constant and loss tangent, and its mechanical performance. It was found that there exists an optimum value of VTMS concentration (about 0.6 phr) corresponding to the minimum water tree length. The water tree resistance mechanism of silane‐grafted XLPE was proposed on the basis of the process of silane hydrolysis and crosslinking. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

含镶嵌块单搭接接头应力分布的数值分析

利用有限元方法研究了金属镶嵌对单搭接接头应力分布的影响。结果表明,采用镶嵌块组成混合连接接头,改变了接头的应力流线分布,镶嵌块承载,降低了搭接区中部胶层中的应力;同时使被粘物中部的应力增大,提高了接头搭接区中部的承载能力;在重要部件或承载较大等情况下使用胶接接头,建议采用金属镶嵌方式对接头增强,具有更强的承载能力和可靠性,有重要的实用价值。     

Impedance analysis for condition monitoring of single lap CNT-epoxy adhesive joint

Multi-Walled Carbon NanoTubes (MWCNT) are ideally suited to be used for damage sensing in fiber reinforced composite materials, and are used for structural health monitoring in adhesive joints. In this work, the capability of MWCNTs for condition monitoring of a single lap Al-Al adhesive joints (SLJ) under shear load is studied using impedance measurements. Different weight percent of MWCNT, i.e. 2.5, 6 and 9 wt.% are added to epoxy adhesive. Epoxy adhesive containing 9 wt.% MWCNT is identified during shear loading to have the highest ultimate strength among the considered specimens and provide the best sensory properties. To provide a more concise evaluation of the damage progression in the adhesive layer under shear stress, artificial defects are inserted into the SLJ specimens. The effects of square and circular defects on the damage progression in the adhesive layer are studied. The results show that primary microcracks are initiated at and consequently develop from the defect boundary in the adhesive joints with larger size of defect. It was found that the shape of the defect does not have a significant effect on the impedance response and sharp resistance changes for specimens with circular and square defect areas of 70% overlap area were about 4.55 and 4.2% respectively. Additionally, when the crack grows entirely through the adhesive layer, a nonzero slope of the resistance change resulted even for low levels of shear displacement.     

CN1.5-35/5型汽轮机单机运行可靠性分析

云天化集团江川天湖化工有限公司80kt／a硫磺制酸装置于1997年初建成投产。该装置配备有1500kW汽轮发电机组。2003年1月，35kV降压站扩容须停电96h。公司拟在此期间硫酸装置不停车，由自备的汽轮发电机组供电。为此，进行了汽轮发电机组单机运行供电可靠性的分析。     

Optimal design of an adhesively-bonded corner joint with single support based on the free vibration analysis

This study investigates the three-dimensional free vibration behaviour of an adhesively-bonded corner joint with single support. The modulus of elasticity, Poisson's ratio and density of adhesive were found to have negligible effects on the first 10 natural frequencies and mode shapes of the corner joint. The effects of the geometrical parameters, such as support length, plate thickness, adhesive thickness and joint length, on the natural frequencies, mode shapes and modal strain energies of the adhesive joint were also investigated using both the finite element method and the back-propagation artificial neural network (ANN) method. The free vibration and stress analyses were carried out for the corner joints with various random geometrical parameters so that a suitable ANN model could be trained successfully. The support length, plate thickness and joint length all played important roles in the natural frequencies, mode shapes and modal strain energies of the corner joint, whereas the adhesive thickness for the range of adhesive thickness studied had only a minor effect. The Genetic Algorithm was also combined with the present ANN models in order to determine the optimum geometrical dimensions which satisfied the maximum natural frequency and minimum modal strain energy conditions for each natural frequency and mode shape of the adhesively-bonded corner joint.