共查询到19条相似文献,搜索用时 750 毫秒
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针对现有热采测试工艺和技术不适应水平井热采测试需要的问题,研究开发了光纤光栅监测技术,并开发了测试光缆水平井施工工艺设备,解决了测试光缆的水平段推入问题。经室内实验和现场试验,各项技术指标均达到设计要求。光纤光栅监测技术对测量信息采用光谱频率和波长编码,测量距离和测量信息不受光源功率、光纤弯曲等因素影响,可在一支特制的光纤上准确定位测量多组光栅传感器,实现了温度与压力的同步连续测量。采用耐温400℃的高分子材料屏蔽铠装成井下测试光缆,光纤和传感器封装后可抗5t的拉力,传感器安装在一个复杂的结构内。通过井下热动态变化监测,可确认合理的注汽量和焖井时间。当井下注汽温度与压力的动态变化稳定,井下温场与注汽参数达到热平衡时为最佳注汽量;当油藏汽腔消失,温场降速平稳,压力下降幅度平稳时,即为合理的焖井时间。 相似文献
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介绍了超声波明渠流量计测量的原理以及通过测量水深公式计算流量,对在线监测设施进行对比确认。 相似文献
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针对光纤复合架空相线(OPPC)预绞式耐张线夹处光纤温度对OPPC使用寿命影响的问题,文章提出在耐张线夹处加装一根截面相等的分流线的方案,并采用光纤测温法对3种试验规格的OPPC(630/45、400/50、185/30)进行“电流-温升”试验。试验结果表明,未加装分流线时,当非耐张线夹处OPPC表面温度为设计要求的70℃时,此处光纤温度小于80℃,而3种规格的OPPC耐张线夹处内部光纤温度均大于95℃,超过了公认的85℃的光纤最高安全运行温度;在加装分流线后,耐张线夹处光纤温度降至85℃以下,避免了长期的高温环境加速光纤涂层的老化而失去对光纤的保护,保证了OPPC的30年设计寿命。 相似文献
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新型弱光纤阵列分布式测量技术是大坝渗流监测的新技术。根据弱光纤光栅测温原理、对流传热方程组和牛顿冷却公式,推导出热光纤渗流监测理论公式。设计了基于加热弱光纤监测渗流的圆筒模型试验,通过光纤周围温度场与渗流场的耦合关系,间接获得圆筒模型的渗流状态。试验结果表明,温度边界层是影响温度场和渗流场的重要因素,渗流水温度对温度边界层影响较大;渗流量与温差ΔT的线性度高;渗流流速u在0.02~0.08cm/s时与ΔT/θ(θ为光纤测量温度与渗流水温度之差)拟合关系式的各项系数与理论推导公式相近。 相似文献
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针对传统双端行波测距技术中线路双端时钟需精确对时的问题,将双端行波测距方法与光纤通信技术相结合,提出了一种基于光纤时间同步的双端行波故障测距新方法。该方法首先利用小波模极大值理论检测故障初始行波到达线路两端的时刻和极性,并根据极性判断故障线路;然后,在故障初始行波到达线路两端后,经光纤通道分别向对端发射脉冲信号,利用相关算法自动检测脉冲信号到达对端的时刻,并根据光纤通道传输时延确定故障初始行波到达线路两端的绝对时刻;最后根据双端测距方法确定故障距离。仿真结果验证了该方法的可行性。研究成果具有较高的工程应用价值。 相似文献
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针对土石坝、堤防和堰塞坝等结构无法通过预埋设备实现渗透稳定性监测的问题,提出一种使用塑料光纤监测渗流泥沙含量的方法,即考虑不同的光波透射距离及不同泥沙含量对光能损耗的影响,间接实现结构渗透稳定性的监测。使用透射距离为2.3 mm的两种实验装置测量0~800 NTU的泥沙悬浊液,研究光能损耗与悬浊液浊度、透射距离的关系。结果表明,光能损耗幅度与泥沙悬浊液浊度呈线性变化,损耗幅度随浊度的增大而增大;光能损耗速度随透射距离的增加而增加.2、3 mm透射距离装置的光能损耗速度分别为2.38、2.75μW/100 NTU。试验验证了光能在泥沙悬浊液中的损耗规律基本符合郎伯-比尔定律,并且透射距离影响装置的监测性能,证明运用塑料光纤监测渗流泥沙含量,从而实现结构渗透稳定性监测是可行的。 相似文献
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10 kV配电线路综合故障定位方法研究 总被引:2,自引:0,他引:2
针对配电网的特点和故障定位的难题,对传统的故障定位方法进行了分析。在总结这些方法的基础上,提出了利用多种信息来构造一种基于行波-直流法的综合定位方法。本文在深入研究C型行波定位法的基础上,为了更明确地确定故障的具体位置,提出了采用直流注入法作为补充的行波-直流综合故障定位方法,其目的是利用不同方法的互补性来提高故障定位的准确性。该方法分2步进行定位,首先利用C型行波法确定故障距离,然后利用直流法确定故障分支。这种行波-直流综合故障定位方法充分利用了行波法[1]操作简单、定位速度快,以及直流定位法应用范围广、能准确确定故障分支的优点,可以实现精确故障定位。理论分析和ATP仿真结果表明:综合方法不受网络结构、分布电容和线路参数的影响,能够准确地确定配电网单相接地故障位置。 相似文献
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The recent moves towards the insertion of biofuels in the energy matrix of a number of countries are opening new prospects for agricultural production and for agroindustrial chains. The emergence of this new productive base raises new research issues: in what circumstances are the structuring, organization and implementation of these biodiesel productive chains taking place in Brazil? What are the effects of biodiesel production on local economies? Hence, the central objective of this study is identifying their economic and social impacts at the regions where they are installed. The analytical structure was constructed based on theories of regional and spatial economy: location coefficient, shift–share, theories of industrial location. A preliminary analysis identified that a biodiesel productive arrangement is emerging in the State of Piauí, Northeastern Brazil, with the purpose of stimulating regional development using alternative oil-bearing crops. However, the agricultural project in the town of Canto do Buriti/PI has faced problems of both a cultural and productive nature. Preliminary findings reveal productive, organizational, managerial and governance related difficulties and challenges that need to be faced when establishing a new productive base in a location that up to that point lacks a productive tradition. 相似文献
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This paper describes a new method of locating the section where an electrical fault occurs on a power transmission line using Composite Fiber-Optic Overhead Ground Wires (OPGWs). This fault location (FL) method locates the fault section by measuring the current induced in the ground wire (GW), i.e., OPGW in this system. The OPGW currents are measured at many towers which divide the power line into sections. Data is transmitted to a central monitoring station as an optical signal through the optical fibers included within OPGW. Prior to the development of this new FL system, a simulation of power line faults using Electro-Magnetic Transients Program (EMTP) was conducted. As a result, the following two points were clarified; 1) Since OPGW current changes with line condition, it is quite difficult to define a fixed threshold level to locate fault sections accurately. 2) The distribution pattern of OPGW current along the power line has clear features around the fault point, so it is possible for electric power engineers to find the fault section by relative comparison. Therefore, the FL algorithm to be developed should have the capability of finding out the fault section with a human-like method of recognition. Fuzzy Theory, an attempt to include this kind of humanlike way of thinking into computers, was investigated and a new FL method applying this theory was developed. Fig. 1 shows the OPGW current distribution pattern of a typical grounding fault calculated by EMTP as an example. 相似文献
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浅谈汽车进气系统的设计布置 总被引:1,自引:0,他引:1
分别论述了汽车原始进气口、空气滤清器、进气管路的布置与安装要求及空气滤清器的选型。发动机出现的早期磨损、烟大、油耗高、无力等故障与汽车进气系统设计布置、安装不合理有关,为了使汽车进气系统布置得更合理,发动机生产企业与汽车生产企业在新车型开发时应进行联合开发,并且在样车装配完成后要进行联合评审确认,对既有车型的进气系统应进行联合改进。 相似文献