湖南澧水皂市水电站尾水肘管安装

湖南澧水皂市电站装有2台混流式水轮发电机组,单机容量60 MW,总装机容量120 MW.皂市水电站尾水肘管设计采用了钢衬型式.这种新方式得到更广泛采用,施工前对相关规范进行了认真的研究,制订了严格的施工工艺,从而保证了施工的质量,圆满的实现了设计意图.尾水肘管安装质量控制的要点为尾水肘管瓦片拼装断面尺寸;管节与管节对接缝周长差应均匀分布;就位安装调整要控制进出口中心、高程、方位尺寸;尾水肘管一期预埋基础一定要牢固可靠;拼装、安装对焊缝焊接要求较高,并应严格控制焊缝处理和焊接速度.     

龙滩水电站尾水管肘管安装

龙滩水电站水轮机尾水管肘管分为13节管段制造，每节肘管段由若干块厚度为25mm的Q235-B钢板卷制的瓦片组成。最重的管节，约16．19t，最轻的管节也有10．82t。肘管段尺寸大、刚度小，为保证安装质量，运输方法根据不同管节的具体情况选用单放或侧放形式。在厂内，利用200kN的临时吊车配合50kN和100kN的导链吊装就位和调整。肘管的安装共有12条环缝，每条环缝的焊接收缩量要控制在2-3mm之间。焊接时有多名焊工均匀分布在各段同时采用分段、退步、对称焊接。安装从第13节（为最下面的一节）开始；依次为第12节，直至第1节。采用该安装工艺取得了很好的效果。     

苗尾水电站水轮机尾水管的安装

苗尾水电站350MW水轮机尾水管采用钢衬内壁,由肘管和锥管组成.锥管进水口与基础环连接,肘管进水口与水轮机锥管连接,肘管出口节与尾水混凝土浇筑的尾水扩散管连接。就水轮机尾水肘管和锥管结构特点、安装工艺、焊接工艺等进行分析。目前已顺利完成所有尾水管的安装和焊接工作,各部件安装质量和安装效率均保持在较高水平,为苗尾水电站按期投产发电和机组长期稳定运行奠定坚实的基础。     

苏阿皮蒂电站混流式水轮机组尾水肘管安装要点

根据苏阿皮蒂电站混流式水轮机尾水肘管的结构特点,分析安装过程中容易出现的问题,制定了合理的安装要点。在肘管钢衬运输至工地后,利用提前搭设的组装平台将分瓣的钢衬分段拼接,再运至现场完成分段肘管整体组装焊接与检测工作。由于施工准备充分,配置资源齐全,施工组织严密,施工过程监控得力,保障了肘管优良的安装质量。     

金沙江向家坝水电站地下厂房工程进入机电安装阶段

6月29日,世界上最大的水电机组一金沙江向家坝水电站右岸地下厂房首节尾水肘管顺利吊装就位,标志着向家坝水电站地下厂房工程从土建施工阶段进入机电安装阶段。向家坝水电站地下厂房共设置4台机组,每台机尾水管采用相同的设计结构尺寸及重量,由肘管和锥管组成,肘管由13节组成,锥管由4节组成。尾水管断面形状为圆形,最大直径达13．31m。     

乌东德水电站大尺寸薄壁型尾水肘管安装质量控制

乌东德左岸地下电站水轮发电机组单机容量850MW,其尾水肘管属大尺寸薄壁结构,安装技术要求较高,质量控制难度大。结合乌东德左岸电站尾水肘管结构设计特点,针对大尺寸薄壁结构形式,主要从肘管安装、环缝焊接、二期混凝土浇筑等几个方面分析了大尺寸薄壁型尾水肘管安装的质量控制核心要素,相关分析成果在实际安装过程得以实践,取得了良好效果。     

立式水轮机组尾水肘管斜向布置的安装控制工艺

落水洞水电站为轴流转桨立式机组,其尾水肘管采用斜向布置设计,尾水肘管中心线与水轮机组Y轴线存在9°偏差。为保证尾水肘管安装质量,控制安装精度,在尾水肘管安装过程中,通过一定的理论计算,将抽象的角度控制数据转换为直观的距离控制数据;并根据此计算结果,使用经纬仪建立1条平行于肘管出口断面的控制线,与其他控制线一起构成一个特殊的测量控制网。采用这种新控制工艺之后,落水洞水电站尾水肘管的安装得以安全高效精确地完成。     

溪洛渡右岸电站尾水肘管安装施工难点和重点控制事项

溪洛渡水电站是金沙江梯级水电站开发建设以来最大的水电站,电站分左右岸两个地下厂房,各设计安装9台770MW混流式水轮发电机组,是继三峡电站后国内已开发建设中总装机容量最大的水电站。电站尾水肘管采用钢衬内壁,肘管进水口与水轮机锥管连接,出口节与尾水混凝土浇筑的尾水管连接。笔者就肘管安装定位控制、环缝焊接中的几项重要控制项目的施工方法和施工对策进行分析,可为今后同类型大型肘管安装提供参考。     

紫坪铺电站尾水肘管现场安装及质量控制

水电站尾水肘管的安装质量直接影响到机组的振动、出力和空蚀．本文结合紫坪铺电站4#机尾水肘管的安装实践．就如何根据现场实际情况制定最佳的施工方案．提高水轮机尾水肘管的安装质量进行了论述。     

亭子口水利枢纽电站尾水肘管制造质量控制

尾水肘管制造是一个综合性的制造工程,在技术准备充分的前提下,加强生产过程中各工序的质量控制是保证整个尾水肘管产品质量的关键.亭子口水利枢纽工程电站尾水肘管制造着重从钢板进厂、下料、卷板、组装、焊接及防腐等几个方面进行质量控制.目前,已基本制造完成,质量满足工程要求,质量控制效果较好.     

饱和砂土地震液化大位移机理研究

饱水砂土地震液化大位移会对土工构筑物造成严重的危害,对其机理的把握是大位移预测的前提和基础。本文对饱水砂土进行了振动液化后的静扭剪及再固结试验,结果表明液化后静加载曲线可分为两段：低强度段、强度恢复段;低强度段的模量极低,在较小的剪应力作用下应变即迅速增长,强度恢复段试样的强度则逐步得到恢复。由液化后静加载应力应变曲线...     

河流水环境容量一维计算方法

河流水环境容量传统一维计算方法,存在初始假定条件下计算河段全程水质超标和排污口断面污染物混合浓度超标幅度过大的问题。针对此问题,提出考虑设计河段水质达标比例、设计断面水质超标幅度和设计河段计算单元长度的计算方法。以计算河段沿程污染物平均浓度达标为条件确定设计河段水质达标比例;借用稀释度理论方法确定设计断面水质超标幅度和设计河段计算单元长度。作为实例,对广西左江的某河段进行计算分析,容量计算安全性得以提高。     

用超声波CT探测混凝土内部缺陷

介绍了超声波CT的原理、反演算法、测线布置以及网格划分，利用所编制的超声波CT程序对某工程桩的一段进行层析成像，给出了测区混凝土超声波CT成像图—等值线和色谱图，据此确定质量异常区的位置、尺寸，以推断混凝土内部缺陷．     

三峡工程左岸电站机组调试动力响应分析

介绍三峡左岸电站1号机组在调试、试运行过程中,几种典型运行工况下厂房和引水钢管等关键部位的动力响应测试,并将测试结果与钢管充水过程的测试结果进行比较.结果表明,引水钢管测试部位的应变变化规律和钢管充水过程测试的应变变化规律相一致,说明引水钢管应变变化较大主要是钢管内水压力发生变化所致;机组甩负荷瞬间厂房和引水钢管测试部位的振动响应最大,但振动能量量值不大,说明机组在正常运行过程中不会危及结构物安全.     

基于ANP-灰色关联TOPSIS法的引水隧洞病害安全性评价

为客观评价西北地区引水隧洞病害安全状态,结合西北地区引水隧洞在运营期存在的病害问题,建立引水隧洞病害安全评价指标体系。应用Super Decision软件用ANP法确定各指标权重,在传统TOPSIS法的基础上加入灰色关联理论,构建西北地区引水隧洞病害安全评价模型。运用该模型以引大入秦工程盘道岭隧洞6个典型隧洞段为研究对象进行病害安全性评价,得出各隧洞段病害安全等级。评价结果客观准确,验证了所建指标体系及模型的科学合理性,可运用于长距离引水工程安全研究方面。     

Distribution of Botia superciliaris (Günther, 1892) ichthyoplankton in the upper mainstem of the Yangtze River preimpoundment and postimpoundment of the upstream dam cascade

Dam cascades have been a major threat to fishes of the upper Yangtze River. The remaining lotic river segment of the upper mainstem between the Xiangjiaba Dam (XJD) and the Three Gorges Reservoir (TGR) may serve as a critical refuge for endemic fishes. We investigated distribution of ichthyoplankton Botia superciliaris, an endemic species, at three sections preimpoundment and postimpoundment of the XJD, that is, Yibin (close to the XJD), Zhuyang (in the middle of the segment), and Mudong (in the tail of the TGR). Preimpoundment of the XJD, larvae occurred in all three sections, and their abundance tended to be highest at Yibin and lowest at Mudong. Postimpoundment, larval abundance dramatically decreased in all three sections. In particular, no larvae were found at Yibin, and larval abundance tended to be higher at Zhuyang than at Mudong. Eggs were collected from all three sections, and those from Zhuyang accounted for over 90% of the total. Initiation of egg occurrence at Yibin was approximately 1 month later than at Zhuyang and Mudong. Water temperature was lower, and water transparency was higher at Yibin than at Zhuyang and Mudong postimpoundment. We suggest that the decrease in abundance and delayed presence of ichthyoplankton at Yibin postimpoundment of the XJD reflected the impact of upstream dam discharge and that the lower abundance of ichthyoplankton at Mudong compared with Zhuyang both preimpoundment and postimpoundment of the XJD reflected the influence of inundation by the TGR. We recommend that the river sections around Zhuyang become high‐priority conservation areas     

The Selwyn River of New Zealand: a benchmark system for alluvial plain rivers

Most of the world's alluvial plain rivers have undergone hydrological and geomorphical modifications due to water abstraction, dam and levee construction, gravel mining and other human activities. Some of these rivers function as benchmark systems for identifying and quantifying the ecological responses to hydrological and geomorphological changes. Benchmark systems are critical for understanding these responses, for predicting the effects of future changes, and for trialling restoration and mitigation measures. The Selwyn River of New Zealand is a benchmark system for undammed alluvial rivers that are under intense pressure for water abstraction, and are subject to large flow fluctuations. The Selwyn is a remarkably complex river, and increased understanding of this system will provide insight for understanding and managing other rivers in its class. Hydrological properties that characterize the Selwyn include strong surface water–groundwater interactions, contiguous ephemeral, intermittent, perennial‐losing and perennial‐gaining reaches and an expanding and contracting dry segment that persists for most of the year. The dry segment, in combination with broad spatial variation in aquifer structure and rainfall, cause the upstream (runoff‐fed) and downstream (groundwater‐fed) river sections to function very differently. These sections are also dissimilar in channel morphology; the upstream section has a braided planform, with mobile bars, and abundant islands and remnant channels, and the downstream section has a single, meandering channel, stable bars and no islands. As in many alluvial plain rivers, large floods drive reach‐scale channel evolution. This paper introduces a long‐term research program that is underway at the Selwyn River, and explores the hydrological and morphological dynamics that characterize the river. We focus on groundwater–surface water interactions, flow‐permanence patterns and flood‐dependent geomorphology. Hydrological and meteorological data are summarized in a conceptual model of relationships between prevailing weather systems, runoff, aquifer recharge and river flow. The physical template described in this paper governs ecological processes such as dispersal, succession and nutrient cycling. A conceptual model is proposed to organize predictions about dispersal in response to changes in hydrological connectivity. Copyright © 2007 John Wiley & Sons, Ltd.     

五强溪水电站工程建设中一些重大技术问题的决策及效应

五强溪水电站工程最后一台机组已于１９９６年１２月投产发电。回顾总结建设施工过程中施工导流三期改二期，提高坝基开挖高程，厂房左导墙与５号机组混凝土分开施工，大坝混凝土通仓薄层浇筑，选定坝顶门机安装场地，坝顶门机预应力梁改钢梁，人工砂石系统技术攻关及增容改造等重大技术问题的科学论断、正确决策、团结实干，既赢得了工期，也减少了工程量，从而保证了全部工程按期投运总目标的如期实现。     

Computational and experimental test of self starting regimes for the in-house needs of the PGU-450 steam-gas unit at the Kaliningrad TÉTs-2 Heating and Power Plant during supply disruptions

The major stages of a computational test of the self starting regimes for the in-house needs of unit No. 1 of the 450 MW steam-gas unit at the Kaliningrad TéTs-2 Heating and Electric Power Plant during supply disruptions are described. The results of an experimental test of five regimes are described and compared with the computational data. The results are analyzed. Recommendations are made for changes in the automatic reserve switching algorithms for the 6-kV sections, which, when realized, will ensure easier self startup for the mechanisms providing for in-house needs during supply disruptions. __________ Translated from élektricheskie Stantsii, No. 4, April 2008, pp. 46–55.