抽水蓄能机组水泵水轮机模型测试

针对国内首次抽水蓄能电站水泵水轮机组第三方试验台同台对比试验,进行了水轮机模 型测试方法的改进,解决了水泵水轮机四象限试验、瞬时工况点数据采集、水泵大流量工况压力 面空泡观测等试验技术难点。模型试验取得了理想的效果:效率试验的测试不准确度小于 士0. 2 %,试验工况稳定、数据重复性好,采集的“S”特性区和反水泵区的数据点密集。此次试验 表明,国内试验台有能力完成抽水蓄能水泵水轮机组的模型验收试验,对推动我国抽水蓄能电站 的建设有积极意义。     

洪屏抽水蓄能电站水泵水轮机模型试验分析

江西洪屏抽水蓄能电站水泵水轮机模型验收试验主要包括率定检查、效率和出力试验、空化试验、飞逸试验、低扬程试验、压力脉动试验、轴向水推力试验、活动导叶水力矩试验、压差指数试验、水泵零流量试验、四象限全特性曲线和模型通流部件尺寸检查等。试验结果表明,该水泵水轮机的S特性良好,安全裕度比较大;水泵水轮机的效率和出力、空化、压力脉动等各种性能指标均满足了合同规定及电站运行要求,各项综合性能指标达到国际先进水平。     

回龙抽水蓄能电站水泵水轮机模型验收试验

南阳回龙抽水蓄能电站2台水泵水轮机是立足于国内采购的第一个高水头单级、可逆式机组，水泵水轮机的模型目击验收分为国内中间验收试验和国外最终验收试验。两次试验结果表明：2台水泵水轮机的水力性能优越，能量特性除水泵工况在最小扬程的入力微超外，其余均满足合同要求；在整个运行范围内，基本上能保证在无空化工况下运行，其空化特性、压力脉动基本满足合同要求；哈尔滨电机有限责任公司与日本日立公司两家试验台的配置、精度及分项误差、总的误差等参数非常接近，均满足合同及IEC有关规程要求；目击验收试验数据与预试验数据基本吻合。     

河南五岳抽水蓄能电站水泵水轮机模型验收试验

河南五岳抽水蓄能电站水泵水轮机模型验收试验于2021年12月在DF-150水力机械通用试验台进行。简要介绍了模型水泵水轮机和模型试验台,并对主要试验结果进行了分析,试验结果表明,该水泵水轮机模型能量、空化、飞逸转速、压力脉动、全特性等主要水力性能满足合同要求。     

抽水蓄能电站最大扬程与最小水头比值探讨

为了减少抽水蓄能电站水泵水轮机设计选型时的困惑，解决参数相近的不同项目最大扬程与最小水头比值选择时较大的差别，增加机组安全稳定运行的基础条件，通过对抽蓄电站定转速混流式水泵水轮机最大扬程与最小水头比值分析研究，总结设计单位和生产厂商的经验数据，结合抽水蓄能行业发展趋势，提出了常用的比值范围供行业使用。通过最大扬程与最小水头比值限值的提出，减少不同专业在蓄能项目前期建设条件选择上的分岐，为抽水蓄能机组的长期安全稳定运行创造条件。     

蒲石河抽水蓄能电站水泵水轮机模型验收试验及性能分析

通过对蒲石河抽水蓄能电站水泵水轮机模型验收试验结果进行分析,表明水泵水轮机能量特性、空化特性、压力脉动特性和其它指标均满足合同规定.试验结果可信,模型试验数据可作为原型性能换算的基础.     

南阳回龙抽水蓄能机组水力性能验收试验

南阳回龙抽水蓄能电站是河南省第一座抽水蓄能电站。运用超声波法完成了水轮机工况和水泵工况的水力性能验收试验，试验取得圆满成功。文章就超声波法在抽水蓄能机组上进行绝对效率试验的内容、测试方法以及测试结果进行介绍。     

广东野猪山抽水蓄能电站机组选型设计

广东野猪山抽水蓄能电站水轮机工况发电水头变幅范围为446.9～517.2m,水泵工况抽水扬程变幅范围为457.6～522.9m,安装4台单机容量为300MW的立轴单级单转速混流可逆式蓄能机组。通过对抽水蓄能电站机组选型的介绍和剖析,对抽水蓄能电站水泵水轮机的选型设计进行了完整的总结。     

混流式水泵水轮机主要水力性能参数模型验收试验探讨

介绍了混流式水泵水轮机模型验收试验内容和主要性能参数的验收方式,对包括水泵高扬程区域的驼峰区和水轮机启动工况的不稳定"S"区等主要水力性能参数的试验验收问题进行了探讨,简述了无叶区压力脉动频率特性。     

呼和浩特抽水蓄能电站水泵水轮机模型验收试验

对呼和浩特抽水蓄能电站水泵水轮机的模型验收试验中的能量特性、空化性能及水力稳定性进行了介绍,对水泵水轮机的主要水力性能进行了初步分析,对改善S特性以及对真机的设计及运行提出了建议,可供参考.     

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。     

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.     

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.