气敏半导体元件作为气相色谱鉴测器的研制和应用

近年来,国内外用气敏半导体作为气体鉴测器已很普遍。我们研制了一种N 型气敏半导体作为气相色谱鉴测器,对稀有气体中的微量氢、变压器油中的溶解气体和工厂乙烯车间的大气等分析,以及对高分子热释气体分析和石油勘探中油气层的显示等方面进行鉴测,证明性能良好,可在生产中使用。气敏半导体又称气敏电阻,是一类对气体特别敏感的半导体材料组成的元件,当它与不     

携带式气敏色谱仪试制和调试小结

携带式气敏色谱仪是由中国科学院有机所、无锡县无线电厂和我所共同协作努力下试制成功的。气敏色谱是用N 型金属氧化物制成气敏半导体为鉴定器,分离气体的色谱柱分别用硅胶柱和活性炭柱,以空气作载气,空气采取负压吸入气路系统,以KW—100A 型小记录仪作为二次仪表,因此携带式气敏色谱仪具有体积小、结构简单、操作方便、不需要氢气、氩气高压钢瓶和空气压缩机等辅助设备少的特点。携带式气敏色谱用于检测变压器油中的可燃气,根据可燃气含量大小来判断运行中变压器的内部潜伏性故障。经过与102型气相色谱仪对比试验和现场实测情况来看,仪器性能良好,其灵敏度超过气相色谱仪的热导池鉴定器,接近于氢火焰离子鉴定器,基线稳定性和测     

CL—Ⅱ型高灵敏度氢气测漏仪的研制与应用

在电厂中制氢、用氢、输氢和储氢等设备，经常发生泄漏事件，漏氢等事件直接威胁着安全生产。由于氢气有易燃易爆的特性，又是极易漏泄的气体，因此只有及时、准确地发现漏氢点并及时处理才能保证安全生产。鉴此，我们研制了CL──Ⅱ型高灵敏度氢气测漏仪，应用效果很好。1工作原理CL──Ⅱ型高灵敏度氢气测漏仪由探头、主机、电源报警指示等几部分组成。探头由气敏元件等组成，当设备在发生漏泄的部位接收到氢气后，探头可将氢信号转换成电信号，通过延伸杆传到主机电路进行高灵敏度的分辨，然后将测量的结果依漏氢的程度分成三种情况，…     

MQK—2型气敏元件的原理与应用

MQK-2型气敏元件具有以下特点:①采用烧结半导体所形成的敏感烧结体,具有稳定的R。(即器件在纯洁空气中的阻抗)阻值,从而保证了长期工作的稳定性。②单电源供电,其功耗仅0.7W左右。③对所测试的气体有极高的灵敏度和信噪比。 MQK-2型气敏元件有两种型号。MQK-2A型适用于天然气、城市煤气、石油液化气、丙丁烷及氢气等;MQK-2型适用于烟雾等减光型有害气体。 器件的性能参数 灵敏度:S=R_。/R_x为10～30。常见为QM系列的S值仅8左右。R_x为器件在丁烷浓度为0.2％时的阻抗,测量电路见图1所示。     

基于多维参量复合感知的变压器套管智能监测

套管是变压器的重要组部件,为实时监测其运行状态,避免引发严重事故,开发了基于油中溶解氢气、油压、油温、微水、介损、电容、局放多维参量复合感知的变压器套管智能监测系统。研制了集成钯镍合金氢气传感技术、压力感知技术、宽温域温度传感技术、痕量微水测量技术的四量融合微型传感器,开发了基于微电流检测技术的介损–电容–局放一体化传感器,实现了套管物理、化学、电气多参数的高精度在线监测。测试结果表明：传感器氢气体积分数测量范围为0～10^–2,测量精度可达10%;压力测量范围为0～1.0 MPa,精度优于0.3%;温度测量范围为–40～85℃,精度优于±1℃;微水体积分数测量范围为0～10^–3,测量精度±5%;相对介损测量误差绝对值小于(标准读数×1%+0.0001),相对电容测量误差绝对值小于0.1%;绝对介损测量误差小于(标准读数×1%+0.000 1),绝对电容测量误差小于(标准读数×0.1%+1 pF);局放信号分辨率为5 pC。装置性能完全满足变压器套管在线监测要求,已在多座330 kV和750 kV变电站挂网运行,为变压器套管的安全运行提供了可靠...     

牵引变压器绝缘在线监测系统下位机系统的设计实现

从数据采集单元、主控制电路结构、单片机程序、上下位机通信协议等方面全面地介绍了牵引变压器绝缘在线监测系统下位机系统的设计实现.系统可以作为单组份气体氢气、多种故障气体、油中微水在线监测系统的下位机系统.实验室模拟实验表明:采用该牵引变压器绝缘在线监测系统测得的油中溶解气体浓度与用AD900气相色谱系统测得的浓度相对误差不到5%.     

5 kW氢—空质子交换膜燃料电池系统设计研究

介绍了5 kW氢-空质子交换膜燃料电池系统的基本组成原理,对该系统重要组成部分(包括反应气供给系统、水/热管理系统、控制及安全系统)进行了功能分析和系统设计.所设计的系统中,反应气供给系统由燃料(氢气)供给子系统及氧化剂(空气)供给子系统组成,水/热管理系统由加湿子系统及冷却子系统组成,并给出空气量、氢气量及加湿量的详细计算方法,为5 kW氢-空质子交换膜燃料电池系统设计提出适应性解决方案.     

用QM——J1型酒敏元件自制酒敏电器

QM-J1型酒敏元件是气敏元件中的一种。它的阻值随酒中酒精(化学名称为乙醇)浓度的变化而变化。可以把被测气体的不同浓度转变成不同电信号,由它制成的酒敏断电器可用于交通管理,有效阻止酒后     

氢冷发电机真空法投排氢的安全分析

氢冷发电机投氢或排氢通常采用二氧化碳作为中间介质,与空气或氢气进行置换。这样一次投氢或排氢大约需3～4 h才能完成,不但费时费力,而且从经济效益方面也是不可取的。采用真空法投、排氢,仅需40～50min,耗氢量较置换法少50～70 m~3,     

高温固体氧化物电解制氢

正高温固体氧化物电解池(solid oxide electrolyzer cells,SOEC)利用各种可再生能源以及先进核能提供的热能和电能,在高温下将水蒸气高效电解为氢气和氧气,可以实现高达50%的热氢转化效率。SOEC中间利用致密的电解质层隔开氧气和燃料气体并同时传导氧离子;两边采用多孔结构的氢电极和氧电极,以利于气体的扩散和传输。2020年,全球首套商用绿色SOEC制氢设备将在荷兰投入使用。该项目依靠的电力来自清洁能源,利用废热作为热量来源,每千瓦时电能产生的氢气可     

Optimization of a door seal structure of a microwave oven using a FDTD method

The optimum door seal configuration to prevent radiation leakage from a microwave oven is still a manufacturing concern. Here, we propose a numerical algorithm to simulate the radiation propagation along a door seal structure using the finite‐difference time domain method, which is used for a priori shielding efficiency tests. The results agree with experimental data. The critical dimensions of the choke structure were found and high shielding is anticipated for a simpler choke structure. Copyright © 2008 John Wiley & Sons, Ltd.     

一起箱变着火事故分析

介绍一起光伏电站箱变着火事故,分析着火原因,并从产品制造和运行维护方面提出针对性建议,对箱变安全运行具有一定的实际意义.     

Simulation of a generator for a wind-power unit

Analysis of excitation systems of generators for wind-power units is carried out, a software package for generator simulation is presented, and the sequence of the generator design is presented.     

Electric potential near a tip of a local discharge on a conductive film

To develop a propagation model of a local discharge on a wet polluted insulator, the authors have examined characteristics of the local discharge on an electrolytic solution simulating the wet polluted insulator surface. The local discharge was propagated on the solution under the impulse voltage. A shape of a contacting surface between the local discharge and the solution has been already obtained by the authors. By using the contacting surface, an electric potential near a tip of the local discharge on a conductive film of 1 mm in thickness was calculated. Furthermore, the potential was measured with a probe. The calculated values and the measured values of the electric potential agreed well regardless of the propagation length of the local discharge, the width of the conductive film, the resistivity of the conductive film, the peak value of the applied voltage and the applied voltage waveform.     

飞机座舱空气调节系统检查仪

文中分析飞机座舱空气调节系统的功能,研制以单片机为核心的检查仪,实现对飞机空调系统工作性能的检测.实际应用表明,该检测设备性能稳定、操作便捷、可靠性高,提高了维修工作的质量和效率,而且该设备对于相关机型具有一定的通用性.     

On the development of a core for a low-power transformer on a basic of wasteless technology

Innovations in critical technology for the production of magnetic materials is considered. On the basis of these innovations, a new design of a low-power transformer is proposed. The operating characteristics of transformers of the pilot and analog design are studied.     

Development of a deceleration control system for a winding machine based on a microcontroller

The development of an automatic deceleration system for a winding machine in a siderurgy factory is presented in this paper. The proposed system controls the speed of a winding machine in order to obtain the optimum stop point in terms of security and fast production. The system is based on a microcontroller and an extremely simple hardware. The system has been tested for two years and results evince a very good mean time between failures.     

Development of a fault locator for a branch line

Formerly, only pulse radar and the Murray loop bridge could be utilized in a cable fault location method that is applicable to branch lines. Those methods need a terminal connection at the far end. Therefore, it is difficult in fault location involving branch lines. Pulse radar is applicable only for high‐resistance ground faults and the Murray loop bridge is applicable only for low‐resistance ground faults. We have developed current‐detection pulse radar and tested it. In high‐resistance ground fault location, the measured result includes discharge delay error. Therefore, we have proposed an error correction method and confirmed it. In addition, we have designed a new cable fault location method of pulse radar and tested it. © 2000 Scripta Technica, Electr Eng Jpn, 134(2): 19–28, 2001     

一起母线保护不正确动作情况的分析

该文通过对华能大连电厂一次母线故障时BUS1000母线保护动作情况的分析,找出了BUS1000母线保护不正确动作的原因,总结了事故教训,并提出了改进措施.