浅谈凯乐塔水电站计算机监控系统

凯乐塔水电站计算机监控系统采用"国电南京自动化股份有限公司"研制的实时监控系统,由上位机系统和现地控制单元(LCU)两部分组成。上位机采用HERC8000计算机监控系统结构,是整个电站监控设备的中枢系统,通过与现地LCU之间的实时通信,及时收集、处理各现地设备的运行数据和事件信息,再通过终端图形实现对全厂主要机电设备的集中控制和运行监视。本电站按"无人值班"(少人值守)原则设计,采用全计算机监控方式。     

向家坝水电站监控系统设计特点

结合电站大坝布置结构特点以及集控模式下监控系统控制策略,介绍了向家坝水电站监控系统的整体结构和功能设计特点。以大坝结构特点为依托的三网四层分布式网络结构和以域为中心的分区设计有效地提高了监控系统的冗余性和可靠性;多通道多规约的通讯接口设计保证了与集控中心的通讯可靠性;AGC与电网切机容量以及与一次调频之间协作关系的优化设计解决了电站与电网控制策略之间的矛盾;应急补水功能的引入解决了事故情况下机组发电与航运之间的协调的问题。     

瀑布沟水电站计算机监控系统投运初期的专项治理

2009年11月瀑布沟水电站500kV开关站顺利投产运行,标志着瀑布沟水电站的计算机监控系统正式运转。然而,在初期运行时,监控系统缺陷较多,给机组稳定运行造成了一定影响。经分析,电站监控系统运行初期缺陷的主要原因是系统本身设计不可靠、监控系统与其他设备通讯不正常等。针对这一问题,电厂技术管理人员提出并实施了26项治理措施,优化、完善了监控系统程序、界面和通讯,有效地提高了监控系统运行可靠性。     

构皮滩水电站计算机监控系统设计

构皮滩水电站装设了5台600 MW和5台1 250 kW的水轮发电机组,电站监控系统监控对象不仅包括机组等电站机电设备,还包括泄洪闸等设施,分布范围涵盖整个枢纽。介绍构皮滩水电站计算机监控系统的总体设计原则、系统结构、设备配置及功能要求等,为适应监控对象分布范围广等特点,在系统总体结构、控制网及现场总线网络结构等方面进行了优化设计。构皮滩水电站监控系统的结构简单清晰,配置优化合理,有力保障了整个项目的顺利实施和电站的顺利投产发电。     

大黑汀水库东坝电站自动化监控系统设计构想

基于分层分布式网络结构的自动化监控系统对大黑汀水库东坝电站进行改造,以计算机监控系统替代以人工操作为主的监视测量设备来满足水电站的运行要求。针对东坝电站的安装及运行方式提出了切实可行的设计构想及系统组成,系统具有先进性、可靠性、经济性,可操作性极强。     

公伯峡水电站辅助设备控制系统设计

水电站辅助设备的自动控制是电站实现“无人值班”(少人值守)运行必不可少的一部分。文中主要介绍了公伯峡水电站机组辅助设备、全厂公用设备自动控制系统的设计原则、设备配置、运行方式以及与全厂计算机监控系统之间的通信连接。     

机组现地控制单元功能和结构探讨

前言近年来国内已有不少电站采用计算机实行监控,由于微型计算机价格大幅度下降,可靠性大大提高和系统网络技术的应用,对水电站计算机监控系统采用按安装单位划分的分层分布式的系统结构,已成为当今被广泛采用的流行方式。在分层分布式结构系统中,作为其下层的机组现地控制单元应具有什么样的功能和结构,是确定现地控制单元以及整个电站监控系统的结构和配置的基本前提,也是电站监控系统设计中必须解决的重要问题。显然,在设计过程中应根据电站的规模、运行特点和环境要求等具体情况而加以确定。因此,在研究现地控制单     

特大型水电机组计算机监控系统的研制

为适应特大型水电机组水电站的新要求,需要研究和开发新型水电站计算机监控系统.文中简要介绍了特大型水电机组计算机监控系统的结构,系统中采用的面向对象、多层结构、分布式对象、控制安全等关键技术,以及与监控系统相关的机组状态趋势分析系统等.     

微机自动化在农村水电站应用模式及相关设备选型应注意的问题

对微机控制模式在农村水电站应用及要求以及对微机控制的相关辅助设备选型进行探讨,并对电站中控室上位机的配置、系统软件总体结构、计算机监控系统性能指标、计算机监控系统对辅助设备部分选型时应注意的问题进行了解析,并提出了具体的建议及意见.     

乌东德水电站计算机监控系统网络结构设计分析

乌东德水电站监控系统的设计以实现"智慧电站"、"调控一体化"和"无人值班"等为目标,这注定了乌东德电站计算机监控系统的复杂性。经全面梳理分析乌东德电站计算机监控系统网络结构表明,其可靠成熟的通信网络设计,是乌东德电站计算机监控系统稳定运行的可靠保证。     

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。     

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.     

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。     

Desiccation and recolonization of phytobenthos in a regulated desert river: Colorado River at Lees Ferry,Arizona, USA

We tested the recolonization of the phytobenthic community in the tailwaters of Glen Canyon Dam following long- and short-term experimentally induced desiccation. The response of Cladophora glomerata, Oscillatoria spp., miscellaneous phytobenthos species and periphyton was studied over 18 weeks using three treatments: (1) undisturbed control cobbles from the submerged zone; (2) cobbles desiccated and replaced into the submerged zone; and (3) cobbles desiccated and replaced into the varial zone. Periphyton density and compositional response resulting from these treatments were also examined. Desiccation treatments were significantly different in biomass from controls throughout the study. The biomass of desiccated and replaced river cobbles averaged <30% of the controls for C. glomerata and periphyton during the 18-week recolonization period. In contrast, the biomass of the control Oscillatoria and miscellaneous phytobenthos species averaged only 3 and 50% of that in the desiccation treatments, respectively. Cladophora, the dominant alga, comprised 77% of the phytobenthic biomass. A significant positive relationship between discharge, Cladophora and periphyton biomass was present in all treatments, while there was a negative relationship with discharge for Oscillatoria and miscellaneous phytobenthos species. There was a significant inverse correlation, as well as a pattern of separate biomass dominance, between C. glomerata and Oscillatoria. Cladophora was the dominant phytobenthos species on cobbles below the baseflow and Oscillatoria was dominant on cobbles in the varial zone. In general, the Cladophora biomass decreased under intermittent drying conditions, while Oscillatoria declined under permanently wet conditions. Diatom composition was not significantly different between treatments; however, their density was lower on desiccated cobbles. Diatom density on desiccated cobbles in the submerged and varial zones averaged 69 and 42% of that of the controls, respectively. Recovery and maintenance of benthic resources are hindered by fluctuating flow regimes driven by electricity and irrigation requirements. Repeated desiccation of the phytobenthos has major effects on the bottom-up interactions in the Colorado River ecosystem. © 1998 John Wiley & Sons, Ltd.