水电机组实时效率监测系统

简单介绍了基于水电厂监控系统和机组流量实时量测系统的水电机组实时效率监测系统的结构、功能、实时数据的获取和处理。该系统充分利用了水电厂监控系统和机组流量实时量测系统现有的资源，结合了机组效率的计算方法以及数据库和网络技术，经过相关的分析计算，得到机组的效率和特性曲线，并能在网络上进行发布。     

东江水电厂水调数据实时传输系统的实现

基于电力系统实时数据通信应用层协议提出了水调数据远程实时传输应用层协议,并基于此协议实现了基于星形网络结构的东江水电厂水调数据实时传输系统.在系统的开发中充分考虑了系统的稳定性和可靠性要求,实现了水调实时数据的自动传输和水调历史数据的自动补传.近4年的实际运行结果表明,该系统的设计是科学、合理的,运行效果令人满意.     

径流式水电厂实时优化调度系统研发

为满足水电厂实时调度需要,构建了以发电量最大为目标的径流式水电厂实时优化调度模型,采用离散动态规划法逐步逼近寻优计算,开发出径流式水电厂实时优化调度系统。该系统可预报计算未来24 h的入库流量过程,并可实时滚动计算满足约束条件的未来24 h内各时段最优发电运行过程,从而量化指导水电厂实时优化调度。通过对6座径流式水电厂的应用,入库流量计算准确率达98%以上,平均每年可优化增加发电量4 500万k W·h。     

农村水电站最小下泄流量研究探讨

为提高水能资源管理的规范化、标准化、精细化水平,江西省开展了农村水电站最小下泄流量监测研究工作,提出了分析计算最小下泄流量的合理方法,建立了最小下泄流量的推算模型,以期为"绿色水电"建设提供实证数据和技术支撑。     

基于可靠UDP的强震消息触发大坝实时监测系统

地处地震活动区的水电厂对强震安全监测有着实际管理要求,但由于行业标准和管理体制等原因,地震台网监测系统与大坝安全监测系统间是各自独立运行的,难以实现强震发生时对大坝安全概貌进行即时监测与分析。文中论述了强震发生时大坝实时监测的必要性和可行性,并提出了基于可靠用户数据包协议（UDP）通信的强震监测系统对大坝测量系统实时触发的构想。最后,结合强震仪系统和大坝安全信息管理系统,给出了系统的设计实现,并在二滩水电厂得到了实际应用。实践表明,系统运行状况稳定可靠,具有一定工程有效性。     

西藏拉洛水利枢纽及配套灌区工程下泄流量的初步研究

回顾了国内外有关河流生态环境需水的研究进展以及目前较常用的河道内生态环境需水量的计算方法。以西藏拉洛水利枢纽及配套灌区工程为实例,采用多种计算方法对工程拟定的下泄流量方案进行分析比较,并指出工程下泄流量方案存在的问题。分析结果表明,工程拟定的方案在下泄水量方面是满足下游生态环境需水要求的,但下泄流量过程可进一步优化,以减缓引水对下游生态环境的影响。     

中国水电工程生态流量实践主要问题与发展方向

梳理了2001—2015年96个水电工程的生态流量数据,基于ArcGIS平台分析了工程时空分布特征,回顾分析了生态流量的落实情况,分析了生态流量计算方法、泄放方式、保障措施和监测措施的差异及其对保护坝下河段珍稀、濒危保护鱼类的生态效益;重点分析水电工程下泄生态流量的保障情况、目前存在的不足与改进措施。总结了中国水电工程下泄生态流量实践的主要问题,并从生态流量计算原则与流量过程线要求、梯级水库联合调度的考虑、加强河流生态修复中生态流量研究与实践等方面提出了未来的发展方向。     

大峡水电厂机组动能参数在线监测

论述了水轮机、水泵和大管道流量监测的方法，介绍了大峡水电厂机组动能参数在线监测系统，这对于解决水电厂流量效率等动能参数的监测计量问题具有普通应用意义。     

漫湾水电厂机组动能参数在线监测

论述了水轮机、水泵和大管道流量监测的方法，介绍了漫湾水电厂机组动能参数在线监测系统，这对于解决水电厂流量效率等动能参数的监测计量问题具有普遍应用意义。     

大广坝水电厂机组动能参数在线监测

论述了水轮机、水泵和大管道流量监测的方法,在此基础上介绍了大广坝水电厂机组动能参数在线监测系统,对于解决水电厂流量效率等动能参数的监测计量问题具有普遍应用意义。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

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。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

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.