小水电水能计算的简化等流量法

对于有水库调节的水电站的水能计算，通常是用等流量法或等出力法分时段(日或月)长系列计算出力，然后绘制出力-历时曲线，以确定装机容量和多年平均发电量，计算工作量甚巨。“简化等流量法”是把每年的整个供水期作为一个计算时段，推导出调节流量、保证出力及装机容量的计算公式。对于面广量大的小水电的规划设计而言，该方法具有计算简捷、精度可靠等优点。图1幅，表4个。     

大雅河水利枢纽工程电站装机容量的确定

大雅河水利枢纽工程电站设计为调峰电站,按长系列法进行水能调节计算,根据保证出力倍比法估算装机容量范围,确定各装机容量的最优工作深度后,通过单位千瓦电量增幅比较、单位千瓦投资比较、差额内部收益率等方法最终确定电站装机容量。     

太白县将军石水电站水文计算及装机容量的确定

根据太白县的基本水文地质条件和将军石水电站所处的水能开发利用环节,参考相同流域水文站的径流、洪峰资料,较为细致的进行了电站的水文计算,并进一步得出电站的保证流量、保证出力,最终确定了电站适宜的装机容量和发电量,以期为同类工程装机容量的计算提供参考。     

径流式电站水能计算程序

有关径流式电站水能计算的微机电算程序在目前应用较多的有《水利水电工程微机通用程序集》(1.0版)中的Ｃ-11.ＥＸＥ程序。该程序可用于无调节水电站常规水能计算,本人在工作中也常常使用Ｃ-11.ＥＸＥ程序。然而,该程序主要适用于一些装机容量较大(如大、中型)径流式电站的水能计算,其计算成果中采用的单位较大,如发电出力单位为万ｋＷ,电量单位为亿ｋＷ·ｈ。对于一些小型水电站,特别是装机容量在1000ｋＷ以下的小型径流电站的水能计算在采用Ｃ-11.ＥＸＥ程序计算时则常常由于计算单位太大而使得计算结果的精度不高,在确定保证出力、装机容…     

佳民冲水电站水能设计复核

小型水电站水能设计应该是一个比较简单的计算过程,但如果稍有不慎就会造成水电站装机容量选择不合理,造成资源浪费或增加工程投资。文章简要分析佳民冲水电站水能计算,通过作引用流量-发电出力曲线图,提出水电站装机容量选择的新思路,希望在实际工作中有借鉴意义。     

水电站保证出力的计算方法

保证出力计算是水能规划设计中的重要内容,不同调节性能的水电站保证出力的计算方法亦不同。通过对年调节、多年调节以及日调节和无调节水电站保证出力的计算方法的论述及应用实例计算分析,推荐应用等出力法进行年调节和多年调节水电站的计算,应用简化的调节流量法进行日调节水电站保证出力的计算。     

小型径流式水电站装机容量的估算

确定小水电站装机容量的方法,通常采用保证出力倍比法或者是机组年利用小时法。这两种方法,表现形式虽然不同,但两者之间有着内在的联系。目前,一般认为装机容量等于2～4倍的保证出力或者年利用小时达到5000至6000小时,是比较合理的。但是对于一个新建工程要得到这两个指标,必须通过比较繁杂的水文水能计算。首先要拟定一个装机容量,求出其保证出力和年电能,如果符合这两个条件,则认为是合理,的,否则需再拟定装机容量,重新进行计算。而大部分小型水电站均是位于水文资料短     

俄罗斯电力系统中的水电

俄罗斯统一电力系统中，水电站的装机容量为４３００万ｋＷ，占总装机容量的２１％。通过联合电网的高压输电线路进行电网内水电站的联合运行，联网水电站的总保证出力大于各水电站保证出力之和。叙述动力和电网发展规划中采用的水电站水能指标，以及水电站装机投运和水库蓄水的进程。     

等流量法和等出力法在年调节水电站水能计算中的应用

等流量法和等出力法是水能调节计算的2种方法。等流量法计算简单，计算结果也有一定的精度；等出力法比等流量法烦琐，但精度较高。现以年调节水电站为例，介绍这2种方法所进行的水能调节计算，最后对2种方法的计算结果进行分析和比较。在水电站的水能计算中，采用等流量法所进行的水能计算可减少工作量而且计算结果也可满足精度要求。图1幅，表3个。     

马营水电站增效扩容改造方案探讨

马营水电站存在水能利用不充分、水轮机机型选择不合理、设备故障率高、型号落后等问题。为充分利用水能资源,保证电站安全可靠运行,结合对电站所处河道水能资源复核计算成果,并考虑电站挡水、引水、厂区等建筑物及机电设备情况,理确定装机容量为4800kW,选择新型高效水轮发电机组及机电辅助设备。通过技术改造,达到了充分利用水能资源、增加出力、提高效率以及提高设备运行稳定性、安全性等目的,具有显著的经济效益和社会效益。     

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。