弹拉式开度仪安装分析与设计改进

针对弹拉式开度仪安装与维护困难的问题进行了专门研究，从其测量原理和安装特点出发，利用万向轮改变出线方向，将开度仪安装在坝面码盘基架上，以便于开度仪的安装与维护。该方案已在窝水库中成功地应用，适合于在水利及其他行业中推广应用。     

长洲水利枢纽泄水闸开度载荷监测技术改造探讨

笔者针对长洲水利枢纽泄水闸开度载荷监测装置运行过程中存在控制开度偏差大、装置调校复杂等问题,提出了对泄水闸开度载荷监测进行技术改造的方案,并经试验运行证明效果良好,对于其他类似的泄水闸开度载荷监测技术改造有较好的借鉴意义。     

水轮机调速器知识问答(七)

--什么情况下才允许调速器限制负荷运行;巡视调速器和油压装置应检查哪些项目 1.在什么情况下调速器才允许限制负荷运行? 水轮机一般应在自动调速状态下运行,此时调速器的开度限制器应放在最大开度位置,只有在调速系统工作不稳定、电站上游水位过低、机组带病工作等特殊情况下,才允许使用开度限制把导叶开度限制在水轮机必须降低出力的相应位置.     

GPS500型闸门开度检测装置在飞来峡船闸的应用

为了提高闸门控制的可靠性和稳定性,提高船闸的过闸效率,飞来峡船闸在闸门开度控制中选用了GPS500型闸门开度检测装置。此装置测量精度高,性能优良,运行可靠,应用在飞来峡船闸效果显著。     

轴流转桨式水轮机桨叶开度测量技术研究及应用

目前国内水电站轴流转桨式机组桨叶反馈装置均采用接触转换结构,因为接触转换结构的不可靠,导致机组频繁出现故障,成为困扰轴流转桨式机组安全稳定运行的一大隐患。为从根本上解决这一难题,提出采用非接触式新型桨叶开度测量新技术并成功应用,有效地提高了反馈装置的可靠性和测量精度,大大减少了运行维护工作量,效果明显,有很好的推广应用价值。     

洺河节制闸液压启闭机及闸控系统功能完善改造

针对洺河节制闸液压启闭机及闸控系统存在的主要问题,通过将行程检测装置由相对型行程检测装置改为绝对型行程检测装置,开度传感器输出信号由高速脉冲信号改为SSI信号,对存在安全隐患的油温加热装置及不易维护的液压元器件进行更换,增设用于安装SSI采集设备的通信柜,改造数据通信网络以调整PLC组网方式进行了改造。液压启闭机及闸控系统功能完善改造完成后,闸门开度等数据采集准确、高效、稳定,液压启闭机运行维护更加安全便捷,全面提升了闸门远程和现地控制的成功率。     

海口南闸闸门开度测量装置改进及应用分析

闸门运行控制系统的可靠和准确,直接影响水闸工程的精准调度和工程效益的充分发挥。通过对海口南闸现有弧形闸门开度测量装置运行情况进行分析,采取相应改进措施,极大地提高了闸门开度测量的稳定性和精确度,为工程的精准调度运行奠定了良好基础。     

巨型水电站液压启闭机开度控制策略研究与应用

介绍了某巨型水电站基于PLC的液压启闭机控制系统在机组快速门、中孔弧门以及表孔双吊点弧门3种典型闸门中的应用,着重阐述了各类闸门开度信号的检测、处理方法及控制特点。对液压启闭机的运行、维护和检修具有一定的指导意义,对于其他工程的建设具有一定的借鉴意义。     

电站运行大课堂

水轮机调速器知识问答（七）——什么情况下才允许调速器限制负荷运行;巡视调速器和油压装置应检查哪些项目 1．在什么情况下调速器才允许限制负荷运行？ 水轮机一般应在自动调速状态下运行,此时调速器的开度限制器应放在最大开度位置,只有在调速系统工作不稳定、电站上游水位过低、机组带病工作等特殊情况下,才允许使用开度限制把导叶开度限制在水轮机必须降低出力的相应位置。     

电站运行大课堂

水轮机调速器知识问答（七）——什么情况下才允许调速器限制负荷运行;巡视调速器和油压装置应检查哪些项目 1．在什么情况下调速器才允许限制负荷运行？ 水轮机一般应在自动调速状态下运行,此时调速器的开度限制器应放在最大开度位置,只有在调速系统工作不稳定、电站上游水位过低、机组带病工作等特殊情况下,才允许使用开度限制把导叶开度限制在水轮机必须降低出力的相应位置。     

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.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

Serial discontinuities in a Rocky mountain river. II. Distribution and abundance of trichoptera

River regulation in the headwaters and middle reaches of the Gunnison River, Colorado, significantly altered distributions and abundances of Trichoptera fauna. Twenty-five species were collected from mainstream samples, with the greatest species richness occurring at an unregulated, rhithron segment above the central reach dams. At sites immediately below the three hypolimnial-release dams and a reregulation dam, species richness was reduced 35–90 per cent and abundance > 95 per cent. Net-spinning caddisflies were the dominant trichopterans at unregulated sites; Arctopsyche grandis in the upper reaches (218 organisms, 586 mg dry mass m^?2) and Hydropsyche cockerelli, H. occidentalis and Cheumatopsyche pettiti in the lower river (9041 total organisms, 6621 mg m^?2), downstream from the last dam. The observed distributional pattern of low trichopteran densities in dam tailwaters and high hydropsychid densities at sites 60–80 km below the central reach dams is a classic expression of continuum resets and adjustments in response to stream regulation as predicted by the Serial Discontinuity Concept.     

Surveying for Water Resources

Abstract

A professional Land Surveyor (Geomatician) describes the Hydrogeologists' survey requirements of a major water resources assessment for the government of The Sultanate of Oman (1992 to 1996). The need for objective specifications is stated. Specialist terms like geoid, spheroid, Mean Sea Level are explained and how to relate spheroidal levels to the geoid. Methods like traditional survey, satellite survey, and photogrammetry are introduced. The paper encourages coordinated working for the benefit of water resource assessment and recommends employment of the professional land surveyor for major studies.     

The Impact of Economic Development on Water Pollution: Trends and Policy Actions in Malaysia

The paper examines the impact of development activities on water pollution in Malaysia. Hence, the main objective of this paper is not just to examine the trends of development-induced water pollution around the region of the country but to know where the problems are and the policy measures taken by the government. It evaluates the probable causative relationship between problems introduced due to technology employed in water pollution control and governmental policy measures. It examines the relationship between development indicators as sources of pollution and polluted rivers over a period of 12 years. The findings of the paper have shown that despite the policy enforcement actions against the identified sources of water pollution, all the three development indicators (chosen based on those identified sources) still accounted for high percentage of river pollution in Malaysia. The findings of the paper were used to identify the central fact of the location of the problem. Some crucial conclusions of where the problems likely to be, as reflected in the findings, are: (a) the issue of interactive-effects between pollutants that many policy-makers are not aware of. This is when policy measures concentrate only on one source of water pollution; (b) the enforcement strength and/or effectiveness of policy measures themselves; (c) financial constraints to invest in appropriate technology especially sewerage systems for controlling human source of water pollution in the country; as well as those confronting small polluting industries (d) finally, lack of cooperation between government and private business firms to comply with regulatory policies for water pollution control.     

浅淡溢洪道改扩建方案与选择

溢洪道改扩建和进行溢洪道方案布置，要择优选取溢洪道进口型式、防冲消能工，以使其工程量省、施工快、运行管理方便     

Intangible Flood Damage Quantification

Flooding is a natural disaster that may cause tremendous tangibleand intangible damage to the national economy. The tangible damage assessment, i.e. the monetary value of all direct and indirect physical damages, has already been studied, whileintangible damages have not yet been taken into account. Thisarticle, therefore, is the first systematic attempt to assess bothtangible and intangible damages. The new proposed Anxiety-Productivity and Income Interrelationgship Approach (API) has been developed to quantify the intangible damage in monetary terms. The Bangkok area has been selected as the research area because several severe flood events have occurredthere over the last two decades. The 1983 Bangkok flood caused 6600 million baht in damage, according to estimates by the National Statistical Office (NSO). This article examines the totalflood damage (including the intangible damage) at different flood magnitudes. Case studies with and without flood mitigation projects are studied and compared. Furthermore, thisarticle also discusses the improvements over the conventional approach offered by the new API methodology.     

Seasonal variation in nutrient retention during inundation of a short‐hydroperiod floodplain

Floodplains are generally considered to be important locations for nutrient retention or inorganic‐to‐organic nutrient conversions in riverine ecosystems. However, little is known about nutrient processing in short‐hydroperiod floodplains or seasonal variation in floodplain nutrient retention. Therefore, we quantified the net uptake, release or transformation of nitrogen (N), phosphorus (P) and suspended sediment species during brief periods (1–2 days) of overbank flooding through a 250‐m floodplain flowpath on the fourth‐order Mattawoman Creek, Maryland U.S.A. Sampling occurred during a winter, two spring and a summer flood in this largely forested watershed with low nutrient and sediment loading. Concentrations of NO increased significantly in surface water flowing over the floodplain in three of the four floods, suggesting the floodplain was a source of NO. The upper portion of the floodplain flowpath consistently exported NH, most likely due to the hyporheic flushing of floodplain soil NH, which was then likely nitrified to NO in floodwaters. The floodplain was a sink for particulate organic P (POP) during two floods and particulate organic N and inorganic suspended sediment (ISS) during one flood. Large releases of all dissolved inorganic N and P species occurred following a snowmelt and subsequent cold winter flood. Although there was little consistency in most patterns of nutrient processing among the different floods, this floodplain, characterized by brief inundation, low residence time and low nutrient loading, behaved oppositely from the conceptual model for most floodplains in that it generally exported inorganic nutrients and imported organic nutrients. Published in 2007 by John Wiley & Sons, Ltd.     

Experience in the Introduction of Steam-Water-Oxygen Cleaning, Passivation, and Preservation at the TÉTs-23 Cogeneration Plant of the Mosénergo Company

Conditions of the process of steam-water-oxygen cleaning, passivation, and conservation (SWOC, P, and C) of internal heating surfaces of the boiler and the high-pressure feed heater (HPFH) piping over the steam side are presented. The process produces partial cleaning of the internal heating surfaces from scale and yields a corrosion-resistant protective film that hinders corrosion processes both in the operation of the boiler and in the idle period.     

钢筋混凝土三点弯曲梁断裂韧度计算模型

基于虚拟裂缝模型,针对钢筋混凝土试件在三点弯曲作用下开裂截面的受力特征,在合理假定的前提下,给出了一种计算钢筋混凝土三点弯曲梁的失稳断裂韧度的解析方法。然后,应用该方法计算了初始缝高比 α₀（初始裂缝长度与试件高度的比值）分别为0.2,0.3,0.4,0.5的三点弯曲试件的最大荷载和临界有效裂缝长度,进而求得了钢筋混凝土三点弯曲梁的失稳断裂韧度。通过对计算结果与试验数据的误差分析,发现失稳断裂韧度最大误差为4.915%,说明这种方法可以较为准确地预测三点弯曲梁的失稳断裂韧度。在此基础上研究了初始缝高比 α₀对失稳断裂韧度的影响,发现失稳断裂韧度基本上不随 α₀ 变化,失稳断裂韧度可以作为材料常数,应用于裂缝扩展状态的判断。