甲岩水电站机组振动问题分析及处理

针对甲岩水电站2号机组安装调试过程中出现的机组振动问题,通过对机组结构、安装及调试过程中相关记录文件的分析研究,采用排除法对可能引起机组振动的因素进行一一试验排除,从而发现机组振动的原因所在,并最终解决2号机组的振动问题。对引起2号机组振动的机理进行详细地分析研究,找出问题的根源,以此为依据,提出关于水电工程建设的几点建议。     

水轮机发电机振动问题的处理

水轮发电机组由于设计及安装过程中的缺陷,将会导致机组振动加剧,严重威胁机组的安全运行,缩短机组的使用寿命,因此只有解决了机组的振动问题,才能保证机组安全、稳定地运行。     

水电机组振动监测装置的设置

一、设置目的 1.水电机组振动是反应机组运行好坏的一个重要参数,它取决于机组设计、制造水平和安装质量,影响着机组稳定、可靠地运行。随着机组单机容量的增大,机组的结构尺寸相应增大,机械刚度相对降低,振动问题更显突出。因此配置必要的振动监测装置,用以适时监测机组的振动大小。使运行     

立式水轮发电机组振摆研究

水轮发电机组运行的振动和摆度是机组的重要性能指标。降低机组运行的振动和摆度是机组安装过程中的一项重要内容,通过剖析引起立式水轮发电机组转动部分振摆的因素,结合工程实际,提出了在安装调试过程中减小机组振动和摆度的一些方法。     

岩滩电厂振动监测分析系统的振动区域分析和趋势分析

大型水力机组的振动问题一直是影响机组安全运行的重要因素.安装机组在线振动监测分析系统,通过实时或长时段内的监测,可以及时地发现由机组振动表现的故障,达到提高机组运行可靠性的目的.在岩滩机组分布式在线振动监测分析系统中,除包含了一些常规分析方法外,还提供了振动区域分析和趋势分析功能.论文主要讨论与这两种分析相关的数据处理和数据分析的方法.     

小型水轮发电机组运行中的振动分析

水轮发电机组振动是水电站存在的一个普遍问题,有设计、制造、安装、运行等方面的原因。运行中的机组不同程度都存在着振动,当振动超过规定的允许值时,便会影响机组的安全运行和机组的寿命,需及时找出原因并采取措施消除。同时水轮发电机组的振动是一个复杂的问题,但从振动的原因来看,一般有机械、水力及电磁等方面的原因。文章结合实践对水轮发电机组运行中的振动问题进行分析。     

周宁水电站机组超速动平衡试验

周宁电站安装的高水头、高转速机组在超速试验中发生剧烈振动,通过超速动平衡试验情况有所好转,但振动突变现象仍未消涂,提出过速试验中的振动标准问题。     

混流式水轮机转轮倒置安装轴向水推力的计算

目前大中型水电站混流式水轮机轴向水推力大，尾水管中涡带所产生的压力脉动常引起机组振动。如水轮机转化倒置安装，将向下的轴向水推力改为向上，可以抵消机组转动部分的重量；如改变尾水管形状，可以消除涡带压力脉动，减小机组振动。以漫湾电站为例，经过计算说明正常安装与倒置安装轴向推力轴承负荷可大大减小。但倒置安装后其结构问题尚需进一步研究。     

丰海电站灯泡贯流式水轮机运行振动及异常噪声原因分析与处理

丰海水电站灯泡贯流式水轮发电机组在安装试运行过程中,出现机组异常振动和噪音现象,通过对该型机组故障现象和现场试验数据进行分析,查找出引起振动的原因,判定机组振动源,彻底消除机组振动现象。     

丰海水电站水轮机运行振动及异常噪声原因分析与处理

丰海水电站灯泡贯流式水轮发电机组在安装试运行过程中,出现机组异常振动和噪声过大现象,通过对该型机组故障现象和现场试验数据进行分析,找出了引起振动的原因,判定机组振动源后彻底消除了机组振动现象。     

长江中游四大家鱼发江生态水文因子分析及生态水文目标确定

基于长江中游四大家鱼发江量历次调查数据,采用宜昌站作为长江中游水文情势变化分析的控制站,基于其1900~2004年共105年的日径流资料,采用每年5~6月涨水过程数、总涨水日数、平均每次涨水过程日数等3项生态水文指标,分析了四大家鱼发江量与3项生态水文因子的变化关系,认为产卵场所处江段每年5~6月的总涨水日数是决定家鱼苗发江量多寡的一个重要环境因子。根据IHA方法,对宜昌站105年来的生态水文指标分析表明,长江宜昌站生态水文过程的改变并不明显,5~6月总涨水日数变化趋势不显著,显示长江中游影响四大家鱼苗发江量的生态流量过程改变不明显,与前人得出的葛洲坝枢纽修建后四大家鱼的产卵条件和卵苗江汛规律没有变化这一认识一致。但是,随着三峡水库的运行,下游河道的生态环境流量过程会有较大改变,本文建议三峡水库的调控以保障长江中游每年5~6月的总涨水日数维持在22.1±7.2范围内为生态水文目标,即可从生态环境流量过程方面补偿水利工程对中游四大家鱼鱼苗发江量的影响。     

Seminar on Water and Energy,Stockholm, Sweden,August 21, 2005

Abstract

In Europe the implementation of the Water Framework Directive (WFD) will have major implications for water resources management. Part of the Directive requires Member States to implement a comprehensive system of controls (licences) on the allocation and abstraction (withdrawal) of surface and groundwater resources. This paper describes the development of a procedure to help assess and set abstraction licences for agricultural irrigation. The methodology is described with reference to Scotland, a country with limited abstraction control previously and where irrigation is supplemental to rainfall. The methodology combines spatial climatic information using a Geographical Information System (GIS) with data derived from a water balance computer model. The procedure enables the volumetric irrigation demand in a ‘design’ dry year for a given site to be estimated, taking into account local variations in climate, soil type, land use and irrigation practices. The approach provides a scientifically robust framework to allow the regulatory authority to assess the ‘reasonable’ water requirements of individual irrigators and hence develop allocations to satisfy the range of competing demands (e.g. agriculture, industry, and environment) on water resources. The methodology is applicable in other temperate countries where water abstraction controls are required and where appropriate datasets are available. The application of the procedure and its methodological limitations are described.     

Stakeholder-driven,enquiry-driven,or stakeholder-relevant,enquiry-driven science?

There is currently debate within the international hydrological community on whether hydrological science should give priority to providing measurements, knowledge, and understanding pre-determined as being needed by stakeholders, or priority to more basic enquiry-driven science that will stimulate the continued health and growth of hydrology as an important Earth science discipline. Two recent major international initiatives in hydrology reflect these two perspectives. One, the Hydrology for the Environment, Life, and Policy (HELP) program, is primarily fostered by UNESCO-IHP and is focused on stimulating the stakeholder-driven hydrological science required in specific catchments that have become members of a global network. The second, the decade on Prediction in Ungauged Basins (PUB), which is appropriately managed by IAHS, is primarily driven by scientific enquiry and is focused on creating new scientific methods and understanding, albeit with practical application ultimately in mind. This paper summarizes the nature, origins, growth, and progress of these two international programs but also describes the subtly different approach that has been adopted by the U.S. National Science Foundation's (NSF's) Center for Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA). NSF is a federal agency whose primary goal is to ‘enable the future’ by stimulating novel science. Because SAHRA is a federally-funded entity supported by an agency with this goal, the Center clearly cannot operate in stakeholder-driven, response mode in competition with the already effective private U.S. consultancy industry. Nonetheless, SAHRA's mission is to create knowledge and build understanding that will enhance the prospects of sustainable water management in semi-arid regions, especially the southwestern U.S. To resolve this apparent conflict, SAHRA looks ahead to future stakeholder needs and builds its research agenda around selected critical stakeholder-relevant questions that require substantial and sustained investment in basic, multidisciplinary, enquiry-driven science. This paper describes SAHRA's approach and reports on associated research and outreach activities.     

Growth,Reproduction, Mortality,Distribution, and Biomass of Freshwater Drum in Lake Erie

Predominant age-groups in the Lake Erie freshwater drum Aplodinotus grunniens population were 3, 4, and 5 as determined from gill net, trap net, bottom trawl, and midwater trawl samples. Age and growth calculations indicated that females grew faster than males. However, the length-weight relation did not differ between sexes and was described by the equation: log W = ?5.4383 + 3.1987 log L. Some males became sexually mature at age 2 and all were mature by age 6. Females matured 1 year later than males. Three sizes of eggs were present in ovaries; the average total number was 127,000 per female for 20 females over a length range of 270 to 478 mm. Seasonal analysis of the ovary-body weight ratio indicated that spawning extended from June to August. A total annual mortality rate of 49% for drum aged 4 through 11 was derived from catch-curve analysis. Freshwater drum were widely distributed throughout Lake Erie in 1977–1979, the greatest concentration being in the western basin. They moved into warm, shallow water (less than 10 m deep) during summer, and returned to deeper water in late fall. Summer biomass estimates for the western basin, based on systematic surveys with bottom trawls, were 9,545 t in 1977 and 2,333 t in 1978.     

水-能源-粮食纽带关系定量研究方法综述

在总结水-能源-粮食纽带关系研究中, 使用频率较高或潜力较大的 8 种水-能源-粮食纽带关系定量研究方法为: 水-能源-粮食纽带关系工具 2.0( WEF Nexus Tool 2.0) ; 生命周期评价( LCA) ; 可计算的一般均衡模型( CGE) ; 系统动力学模型( SD) ; 气候、土地、能源与水资源策略( CLEWS) ; 基于社会生态系统代谢的多尺度综合评价( MuSIASEM ) ; 市场配置/ 市场配置系统集成模型( MARKAL/ TIMES) 和水资源评价规划模型-长期能源替代规划系统 ( WEAP2LEAP) 。通过总结各研究方法的产生、发展及特性, 并引用案例讨论其适用范围, 分析其优缺点和在使用 时需要注意的问题。在此基础上, 对未来水2能源2粮食纽带关系定量研究方法的发展趋势进行讨论, 认为伴随可持 续发展问题关注度的上升与水-能源-粮食纽带关系内在机理的挖掘, 未来的水-能源-粮食纽带关系定量研究方法将 更加注重量化的精确性和数据的互通以及跨学科研究和多方法的耦合。本文可为水-能源-粮食纽带关系定量研究方法的选择和更新优化提供参考。     

Survival,Growth, and Movement of Subadult Humpback Chub,Gila Cypha,in the Little Colorado River,Arizona

Ecologists estimate vital rates, such as growth and survival, to better understand population dynamics and identify sensitive life history parameters for species or populations of concern. Here, we assess spatiotemporal variation in growth, movement, density, and survival of subadult humpback chub living in the Little Colorado River, Grand Canyon, AZ from 2001–2002 and 2009–2013. We divided the Little Colorado River into three reaches and used a multistate mark‐recapture model to determine rates of movement and differences in survival and density between sites for different cohorts. Additionally, site‐specific and year‐specific effects on growth were evaluated using a linear model. Results indicate that summer growth was higher for upstream sites compared with downstream sites. In contrast, there was not a consistent spatial pattern across years in winter growth; however, river‐wide winter growth was negatively related to the duration of floods from 1 October to 15 May. Apparent survival was estimated to be lower at the most downstream site compared with the upstream sites; however, this could be because in part of increased emigration into the Colorado River at downstream sites. Furthermore, the 2010 cohort (i.e. fish that are age 1 in 2010) exhibited high apparent survival relative to other years. Movement between reaches varied with year, and some years exhibited preferential upstream displacement. Improving understanding of spatiotemporal effects on age 1 humpback chub survival can help inform current management efforts to translocate humpback chub into new locations and give us a better understanding of the factors that may limit this tributary's carrying capacity for humpback chub. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.