单导叶接力器导叶不同步原因分析及故障处理

广州抽水蓄能电厂二期的水泵水轮机为高水头、大容量、高转速的混流式可逆机型。采用单导叶结构可以简化导水机构布置,提高单个导叶的可控制性。经多年检修经验得知,导叶不同步故障是导水机构故障的主要原因之一,从多个方面分析了导叶不同步故障的原因及解决方法,对导叶不同步故障的原因分析及处理有一定指导意义。     

抽水蓄能机组单导叶控制调速器常见故障模式及维护策略

结合多年抽水蓄能机组运维经验,对单导叶控制调速器各种故障模式的识别方法、预防措施、故障处理等进行深入分析,制定对应的维护策略,以减少故障发生的概率,充分发挥单导叶控制调速器的优点。广蓄B厂针对近年来单导叶控制调速器发生过的故障制定的维护策略具有针对性,取得较好效果。     

灯泡贯流式机组导叶外环磨损原因分析及处理

导水机构作为水轮机重要组成部件,导水机构的运行状态影响着整个机组的稳定及安全。控制环在整个导水机构中起着传递导叶开度的作用,其中控制环与导叶外环直接接触,导叶外环承载着控制环的转动力矩及摩擦力矩,导叶外环在水电站日常运作当中发挥着不可替代的作用。它的状态正常与否将决定着机组的稳定性及安全性。因此做好水电站导叶外环的检修及日常维护工作十分重要。本文主要以导叶外环的磨损故障为例,分析可能产生磨损的原因,提出有效的解决办法及预防措施,以保证机组的安全稳定运行。     

广州蓄能水电厂B厂机组导叶轴套选型研究

广州蓄能水电厂B厂4台机组自投产以来,多次出现导叶轴套漏水、损坏等问题,尤其8号机组频繁出现G工况启动时导叶拒动故障。通过综合比较分析,决定后续机组大修选用500SP1-SL464铜基镶嵌自润滑轴套替换500SP1-SL401轴套。8号机组于2012年2月完成大修,从实际运行情况来看,目前导叶轴套未发现漏水,导叶静态试验中导叶开关顺畅,机组小修时检查上下抗磨板无摩擦痕迹,导叶端面间隙正常无变化。     

水轮机导水机构的结构改进设计

现有的水轮机主要采用连杆式导水机构。为简化结构同时减少原材料的消耗,降低生产和制造成本,取消其连杆组件,将连杆式导水机构改为滑块式导水机构,由控制环直接带动导叶臂转动,调节导叶开度,以控制水轮机的流量。该结构简单、新颖,安装、维护方便,实用性强,提高了生产企业和电站的经济社会效益。图6幅。     

水轮机导叶摩擦装置的设计研究

在水轮机组运行中,导水机构通常是利用导叶臂与连板间的剪断销起过载保护作用,在控制环带动活动导叶向关闭方向运动,某些导叶发生卡阻,外力大于正常的关闭力一定值时,相应剪断销就会被剪断。目前有些机组则采用新型的导叶摩擦装置。文章介绍了导叶摩擦装置的主要结构和工作原理,提出了导叶摩擦装置设计时的主要参数,如压紧螺栓的直径大小、压紧螺栓预紧力矩大小的计算方法。     

长洲水利枢纽水轮发电机组重锤关机装置简介

重锤关机作为灯泡贯流机组最有效的防飞逸措施得到了广泛的应用,且重锤关机装置具有多种型式,各有特点。该文针对长洲三个主机厂生产的灯泡贯流式水轮发电机组,介绍其重锤关机装置的原理及主要特点。其中,A厂机组采用单作用导叶接力器模式,B厂采用双作用接力器结合事故配压阀模式,C厂机组采用双作用导叶接力器模式。当机组因事故甩负荷遇调速系统故障而不能正常关机时,三种装置均能实现安全关机,能有效地防止机组飞逸。     

龚嘴水电站机组导叶传动机构的结构改进与技术改造

对龚嘴水电站不同历史时期机组导叶传动机构的结构特点、运行情况进行了分析、比较,为上世纪60、70年代投产机组导叶传动机构的结构改进和技术改造提供了借鉴和参考.     

几种灯泡贯流式机组导水机构工装简介

导水机构是灯泡贯流式水轮发电机组的重要组成部分,主要由外配水环、内配水环、导叶、传动机构、调速机构等部件构成,其主要功能是使水在进入转轮前产生水流环量,并根据机组功率的需要开关导叶调节水流流量,达到预定的出力,水轮机停止运行时,导叶分段关闭切断水流。根据导水机构的结构特点,单支导叶具有各自的传动、调速机构,安装工序较为复杂,单个导叶系统安装调整完毕后方可进行整体的组装,为了提高安装质量及安装效率,介绍几种实用的导水机构工装。     

抽水蓄能电站导水机构的安装施工技术探析

导水机构是水泵水轮机的关键部件,运行环境较为复杂,主要是由导叶、导叶传动机构、导水机构接力器和项盖、底环、控制环等一系列部件组成。根据抽水蓄能电站导水机构的安装程序与技术要点,以海南琼中抽水蓄能电站导水机构安装施工为例,确定导水机构安装工作内容与流程、导水机构安装施工。导水机构安装施工主要包括底环、导叶、顶盖、控制环、拐臂和接力器的组装和安装。最后,提出施工质量保证措施,可为抽水蓄能电站导水机构的安装施工提供保障。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。