在水轮机调速器开发中应重视标准液压件的应用

近十几年来，我国水轮机调速器的液压控制部分的开发研制取得了较大进展，各种产品形式层出不穷，产品质量有了很大提高。但通过液压行业的标准液压件尚未在该行业得到全面普及，制约着液压技术的最新成果在该领域的顺利应用，十分不利于调速器技术的进一步发展与提高。本文从几个侧面概要地分析了在调速器中大量采用标准液压件的可行性，使调速器液压技术及时与现代液压技术接轨，从而推动和促进我国调速器技术迅速跻身世界先进行列。     

水轮机数字控制调速器

水轮机数字控制调速器(以下简称调速器),采用了先进的CMOS元器件,功耗低,工作电源电压范围宽,逻辑摆幅大,抗干扰能力强,温度稳定性好,性能质量高于运放式调速器和TTL式调速器;     

伺服比例阀在水轮机调速器中的应用

水电厂多年来的运行实践表明，在水轮机调速器液压调节柜中采用一种新型的伺服比例阀，取代以往各种形式的电液转换器，可以降低液压调节柜的故障率，提高机组运行的可靠性以致整个电力系统的稳定性，使电厂向实现“无人值班”的目标迈进。     

交流伺服电机在水轮机调速器中的应用

长江科学院控制设备研究所研制的第1台交流伺服电机控制式可编程调速器在广西合面狮水电厂2．0万kW机组上投运近1a，运行稳定、可靠，深受用户好评。该调速器采用交流伺服电机作为电气－机械位移转换装置，取代了传统的电液伺服阀。由于交流伺服电机高可靠性和免维护，较好地解决了调速器的核心部件之一电气－机械位移转换装置的可靠性问题。     

三峡电站水轮机调速器的关键技术及国产化问题初探

针对三峡工程左岸电站采用国外调速器的情况,提出了右岸电站采用国产调速器的建议,并从提高调速器可靠性指标和实现数字化要求出发,提出了三峡电站调速器"优化"设计和重要部件选择上的研究课题,如水轮机调速器系统结构选择与论证、软件模块化设计和研究等。在此基础上,对三峡电站调速器技术方案提出采用全数字式交流伺服电机及驱动器作为微机调速器的数字信号-机械位移转换部件,采用微机调节器加数字式电液随动调速系统结构方案及PC平台大型可编程控制器的建议。     

浅谈水轮机调速器的选型

新建或改扩建的水电厂,都会遇到调速器的选型问题。如选型不当,将会带来种种不良后果。严重时会直接威胁水电机组的安全稳定运行。因此在调速器选型时必须根据调节对象所提供的参数进行必要的分析和计算,确定调速器的容量和参数调整范围,才能获得满意的结果。     

水轮机步进式微机调速器应用研究

以工业控制级单片机80C552为核心，开发出集测频、调速、调功、开停机操作、故障诊断及与上位机通讯等功能于一体的双微机型电气调节器，并与抗油污能力强、定位精度高、漏油量小的步进电机式引导阀及机械液压随动装置相配接，构成了水轮机步进式微机调速器。试验结果表明，该调速器具有良好的静、动态性能，各项性能指标均达到或优于国标GB/T9652.1-1997的要求。     

脉宽调制位置伺服系统在水轮机调速器上的应用

主要介绍了脉宽调制位置伺服系统在水轮机调速器上的应用。阐述了电脉宽调制及脉码调制技术位置伺服系统的基本原理和控制方法，由于其结构简单，抗污染能力强，完全可以取代传统调速器的机械流压系统。     

可编程水轮机调速器

为了满足大型水轮机对调速器高可靠性，高性能的要求，开发研制了“可编程水轮机调速器”。该调速器采用高可靠性的可编程序控制器为硬件主体，配以数字式智能测频模块等少量外围器件，具有良好的性能和很高的运动可靠性。     

我国水轮机数字式电液调速器评述

分析了现代数字式电液调速器的发展及现状，论述了数字式电液调速器发展中所取得的成果及现代电力系统对调速器的要求，并提出了一种基于现场总线的全数字式电液调速器。     

插装式逻辑阀在水电厂调速器系统中的应用

0 引言 插装阀是国际上20世纪70年代后期发展起来的逻辑阀。插装阀是一种将标准插件装入液压集成块体内而形成的阀件,它在液压系统中的作用相当于数字电路中的“与非”门。通过对插装阀的不同组合,可以实现不同的液压逻辑回路功能,因而插装阀又称为逻辑阀。由于插装阀的基本组件均为标准件,而且其阀芯是圆锥形阀芯结构,所以它的可靠性高,即防卡能力大大强于普通的滑阀,并有自清污能力。同时,它的通流能力也比普通的滑阀大得多,还由于其组件均是插装于液压集成块内部的,所以用插装阀组成的液压集成系统的结构大为缩小。集以上诸多优点,使得插装阀在国际上一经推出后,就得到了快速的发展和应用。     

对编写《水轮机》新教材的建议

提出适应新的中等职业《水轮机》教材和课程教学大纲的修改建议。     

EXPERIMENTAL INVESTIGATION OF CHARACTERISTIC FREQUENCY IN UNSTEADY HYDRAULIC BEHAVIOUR OF A LARGE HYDRAULIC TURBINE

The features of unsteady flow such as pressure variation and fluctuation in a large hydraulic turbine usually lead to the instability of operation.This article reports the recent in site investigation concerning the characteristic frequencies in pressure fluctuation,shaft torsional oscillation and structural vibration of a prototype 700 MW Francis turbine unit.The investigation was carried out for a wide load range of 200 MW-700 MW in the condition of water head 57 m-90 m.An extensive analysis of both time-history and frequency data of these unsteady hydraulic behaviours was conducted.It was observed that the pressure fluctuation in a draft tube is stronger than that in upstream flow passage.The low frequency with about one third of rotation frequency is dominative for the pressure fluctuation in part load range.Also the unsteady features of vibration of head cover and torsional oscillation of shaft exhibited the similar features.Numerical analysis showed that the vibration and oscillation are caused by vortex rope in the draft tube.In addition,a strong vibration with special characteristic frequency was observed for the head cover in middle load range.The pressure fluctuation in the draft tube with the same frequency was also recorded.Because this special vibration has appeared in the designed normal running condition,it should be avoided by carefully allocating power load in the future operation.     

ANALYSIS AND ESTIMATION OF HYDRAULIC STABILITY OF FRANCIS HYDRO TURBINE

With the development of large-capacity hydro turbines, the hydraulic instability of hydro turbines has become one of the most important problems that affect the stable operation of the hydro-electric units. The hydraulic vibration and unstable operation of Francis hydro turbines are primarily caused by the unsteady pressure pulsations inside draft tubes. The forced rotating vortex core at the runner exit and the channel vortices inside Francis turbine runners are origins of the unsteady pressure pulsations when operating at partial load. This paper briefly analyzes the hydraulic instability of operation caused by the vortex core and channel vortices at partial load, then, presents a way to estimate the hydraulic stability by calculation of the flow behavior at the runner exit. The validity of estimation is examined by comparison with experimental data. This will be helpful to evaluate the alternative design and predict the hydraulic stability for both the prototype and model hydro turbines.     

NUMERICAL PREDICTION OF SILT ABRASIVE EROSION IN HYDRAULIC TURBINE

1.INTRODUCTIONTherearemanyhydraulicturbinesoperatedinsiltladenriversintheworld.Thepresenceofsolidparticlesintheflowoftencauseabrasivedegradationofcertainpartsofthehydraulicturbinewhichareespeciallyexposedtotheflow.Theerosivewearduetohydroabrasiondependsprimarilyonthesurfacematerialandonthematerialoftheabrasiveparticlesinwater.Thefluiddynamicsoftheparticlemotionalsoplayaveryimportantroleinthistribologicalsystem.Therelativevelocityofparticlesandthefrequencyofimpactarekeyfactorsindetermining…     

水工金属结构安全检测与评估在大坝定检中的应用

阐述水工金属结构安全检测与评估工作研究现状，介绍水工金属结构安全检测与评估内容和方法，结合工程实例介绍安全检测与评估在大坝第2轮定检中的应用。可供其他工程参考借鉴。     

对水轮机自动调速器油压控制电路的改进

YT－1000型油压自动调速器在运行中不能维持正常油压、在不增加任何设备的情况下，只改动二次接线的处理方法，就能消除隐患、解决问题。     

石泉水电厂水轮发电机组自动化元器件改造

为适应水电厂计算机监控系统的要求，石泉水电厂在原有基础上对自动化元器件进行了更新改造。文中介绍了石泉水电厂自动化元器件选型配置及改造前后的运行情况，并对改造经验进行了总结。     

NUMERICAL PREDICTION OF VORTEX FLOW IN HYDRAULIC TURBINE DRAFT TUBE FOR LES

The three-dimensional unsteady turbulent flow is studied numerically in the whole flow passage of hydraulic turbine, and vortex flow in the draft tube is predicted accurately in this paper. The numerical prediction is based on the Navier-Stokes equations and Large-Eddy Simulation （LES） model. The SIMPLE algorithm with the body fitted coordinate and tetrahedroid grid system is applied for the solution of the discretization governing equations.