某巨型水电站进水口快速门下滑分析

机组进水口快速门是电站机电设备的重要保护设备,在电站安全运行中起着关键作用。本文对某电站各机组快速门近一年来的下滑情况进行了统计,并介绍了快速门的启闭工作原理。针对快速门液压系统的多种渗漏形式、温度对于渗漏的影响及位置反馈故障等原因作出详细分析,发现了快速门开度仪反馈量信号跳变并报警的问题。本文针对开度仪信号跳变问题提出加装多台开度仪,并通过逻辑筛选的方式确定取用反馈量。通过快速门持门试验验证了解决方案的科学性、可行性,为今后同类故障的处理提供了参考依据。     

皂市水电站进水口快速门液压启闭机设计

皂市水利枢纽进水口快速门液压启闭机是水轮机组和引水压力钢管的重要保护设备之一,对机组的安全起至关重要的作用.为了确保启闭机安全、可靠地运行,针对启闭机运行速度较快的特点,液压系统中采取了一些较特殊的措施.通过优化设计,使液压启闭机具有系统简单、经济、安全可靠性高的特点,自投入运行以来,工作状况良好,达到了设计的目的和要求.     

快速门液压启闭机几个技术问题的研究

l前言发电是水电站的基本功能之一．进水口快速］司是保证水电站发电机组安全运行的重要设备，其性能如何，能否安全可靠工作将直接影响发电机组的运行安全．相对来讲，快速门的液压系统组成比较简单，控制也不算复杂．尽管如此，作者通过近几年对这类液压系统的研究发现，由于对几个技术问题没有很好解决，其液压系统的设计还存在一些缺欠，应该引起设计和使用部门的重视，并在今后的工程中加以解决．2几个关键位置的压力控制根据工况要求，快速门液压启闭机在实际工作中共有3个工作位需要控制，它们是：“全关位、“‘全开位”和“充水平…     

隔河岩电站进水口快速门启闭机设计

隔河岩电站进水口快速门液压启闭机是水轮机组和引水压力钢管的重要保护设备之一，对机组的安全起着至关重要的作用。为了确保启闭机安全可靠地运行，针对启闭机运行速度较快的特点，液压系统中采取了一些较特殊的措施。通过优化设计，使该液压启闭机具备系统简单、经济、安全可靠性高的特点，自投入运行以来，工作状况良好，达到了设计的目的和要求     

向家坝右岸电站快速门快闭控制回路分析

快速门是水电站机组事故时重要的保护设施之一,快速门的可靠动作对于电站事故时的保护具有重要意义。通过对向家坝右岸电站快速门快闭控制回路的介绍,分析快速闭门控制回路及其电源的可靠性,并提出关于快速闭门电磁阀YV2的改造方案和快速闭门控制回路的注意事项及改进意见。     

回油压力对具有差压式配压阀的液压系统的影响

通过对采用回油调速的中小型水轮机调速器液压系统的分析和改进，提出了回油压力变化对具有差压活塞控制的液压系统的影响可能会造成系统不能正常工作，不容忽视。在采用回油节流调速时，必须注意采取相应措施，消除回油压力的影响，以保证系统正常工作。     

ETS系统可靠性探讨

笔者对某电厂350 MW汽轮机危急遮断系统的可靠性进行分析,并针对该系统在电源回路、AST电磁阀、在线试验逻辑等方面存在的问题逐项进行分析和改进优化,该措施解决了可能导致汽轮机ETS保护误动或拒动的隐患,保证了汽轮机安全稳定运行。     

莲花水电站快速闸门液压系统的设计

0　前　言　　目前水电站快速闸门液压启闭机的液压系统普遍存在的承压低、泄漏大、标准化程度低、占地面积大、安装维护不方便等欠缺。采用插装阀技术设计的快速闸门液压启闭机的液压系统,能够较好地解决上述问题,插装阀具有如下优点:流量大、压力损失小、系统效率高、高压条件下泄漏小、保压性能好、逻辑组合机能好、一阀多用,响应快、噪音低、结构紧凑、便于安装调试和维修,在大型水电站的大型液压启闭机液压系统中具有广泛的应用性。莲花水电站的快速门液压启闭机液压系统成功地采用了插装阀新技术。莲花水电站位于黑龙江省牡丹江地区海…     

潜水推流搅拌器动密封系统技术改进

针对潜水推流搅拌器传统密封结构存在着工况适应性差、机械密封易损坏、防渗漏效果差的不足,提出了内外组合式动密封系统的技术改进措施,新型动密封系统采用了新结构、复合材料、内外组合式配置,缩短了悬伸长度,改善了受力结构,提高了对恶劣工况的适应性.     

改进水电站进水口事故快速门控制策略探讨

透过2009年8月17日俄罗斯萨扬.舒申斯克水电站机电事故,分析了目前国内水电站机组进水口事故快速门控制系统的现状,分析了存在的问题,给出了提高水电站机组进水口事故快速门控制系统的策略建议。可供水电站机电设计、设备或系统研制单位、运行维护等相关技术人员参考。     

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.     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

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。     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

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.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.