Numerical Simulation of Swirling Flow in Complex Hydroturbine Draft Tube Using Unsteady Statistical Turbulence Models

A numerical method is developed for carrying out unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and detached-eddy simulations (DESs) in complex 3D geometries. The method is applied to simulate incompressible swirling flow in a typical hydroturbine draft tube, which consists of a strongly curved 90° elbow and two piers. The governing equations are solved with a second-order-accurate, finite-volume, dual-time-stepping artificial compressibility approach for a Reynolds number of 1.1 million on a mesh with 1.8 million nodes. The geometrical complexities of the draft tube are handled using domain decomposition with overset (chimera) grids. Numerical simulations show that unsteady statistical turbulence models can capture very complex 3D flow phenomena dominated by geometry-induced, large-scale instabilities and unsteady coherent structures such as the onset of vortex breakdown and the formation of the unsteady rope vortex downstream of the turbine runner. Both URANS and DES appear to yield the general shape and magnitude of mean velocity profiles in reasonable agreement with measurements. Significant discrepancies among the DES and URANS predictions of the turbulence statistics are also observed in the straight downstream diffuser.     

安康水电厂3号发电机推力瓦磨损原因分析及处理

本文介绍了安康水电站３号水轮发电机推力瓦的磨损情况，对推力瓦磨损原因进行了分析，认为磨损是由于瓦中部凸变形引起的，而引起瓦变形的主要因素是热变形。推力瓦的热变形主要是由三个分量组成：瓦体与瓦面线胀系数不同引起的热变形，瓦厚度方向温差引起的热变形和瓦面热变形。叙述了推力瓦磨损处理的步骤和采取的主要措施。经过处理后推力轴承运行情况良好。     

试论水电站调峰的节煤效益

本文主要论述水电厂调峰节煤的效益。水电节煤与替代电厂─—火电厂的运行特性有关，本文论述了火电机组的运行及煤耗特性，以数字实例说明了水电厂在日负荷曲线上担负不同的工作位置时，替代煤耗率是不同的。还论述水电调峰，还电、抽水蓄能电站的节煤机制。为水电调峰、水电与火电系统联网及抽水蓄能电站效益的正确评价提供了一种论证方法。     

Development and Evaluation of a New Helical Fish-Friendly Hydroturbine

A new hydroturbine was developed to improve fish survival during their downstream migration. This turbine includes a normal scroll case, few but relatively long wicket gates, a streamlined downturn before the runner inlet, a runner with only three helical blades attached to a tapered hub and a rotating shroud attached to the outside edges of the blades. After design of the turbine using analytical methods and construction of a 1:3.25 scale pilot turbine and flow loop, engineering studies and tests with live fish were conducted at full-scale heads and velocities. Resulting test data indicated that the full-scale turbine would have an efficiency of about 90% and that fish survival would be about 98% for fish 100?mm (4?in.) long. Survival would be greater for smaller fish and less for larger fish. Various improvements to the turbine design were identified prior to full-scale field application.     

庙子头水电站两种堰型选择水闸断面模型试验研究

通过庙子头水电站两种堰型选择水闸断面模型试验研究 ,获得了宽顶堰与驼峰堰的泄流能力曲线和综合流量系数等试验成果。经综合比较分析表明 ,在平底泄水闸上做成较小的曲线型剖面堰型式的驼峰堰 ,可获得较宽顶堰大的流量系数 ,提高了泄水闸的泄流能力 ,从而可减少闸孔数目 ,节省开挖方量和投资     

沙牌碾压混凝土拱坝结构分缝设计研究

沙牌碾压混凝土拱坝高 130m ,具有混凝土工程量大、全年施工、坝体应力水平高、温控措施简单等特点。由于碾压混凝土在施工期的水化热温升要影响拱坝的最终应力状态 ,坝体可因温降收缩而产生贯穿性裂缝 ,从而影响拱坝的整体稳定性 ,因此 ,降低温度作用对坝体的不利影响 ,选择适合碾压混凝土施工的坝体结构分缝设计 ,对高碾压混凝土拱坝设计尤其关键。本文主要介绍沙牌拱坝在这方面的设计研究成果     

水库优化调度中随机动态规划方法的研究与应用

该文应用随机优化方法，以清江隔河岩水电站为例，对水电站的兴利优化调度问题进行了研究。并用此方法建立了隔河岩水电站随机动态规划水库优化调度模型，计算编制了电站的优化发电调度图。     

西北电网水电运行及设备技术改造

本文扼要介绍西北电网中水电的运行情况,并论述机组存在的主要缺陷及其技术改造.     

东西关水电站施工期洪水预报方案编制与反馈设计

根据嘉陵江东西关水电站施工要求、流域暴雨洪水特性和现有水情站网，编制了一套由长、中、短不同预见期方案组成的河系预报方案。经过实际洪水预报，将方案的预报精度、未控区间流量加入影响等信息反馈到方案的再设计中，增补了南充～东西关区间洪水预报方案和报警方案，使原方案的预报精度、可靠性有了较大提高，能为电站施工提供及时准确的洪水预报。     

东西关水电站水工建筑物安全监测设计布置

对东西关水电站水工建筑物的安全监测进行了介绍。叙述了设计原则、闸坝枢纽的原型观测布置、厂房枢纽的原型观测布置、监测内容，并就实施中存在的问题提出了处理建议。