Analysis and Treatment for Vane Swinging Defect of Kaplan Turbine in Nierji Hydropower Plant

轴流转桨式水轮机桨叶在一定工况下的位置稳定与否,对机组运行稳定有重大影响.结合尼尔基发电厂2号水轮机桨叶频繁抽动缺陷的分析和分解检修处理过程,指出了轴流转桨式水轮机桨叶频繁抽动现象的一些原因,并提出了相应的处理方法,为改进设计提供依据.     

轴流转桨式水轮机水头自动跟踪装置的研制

在某一水头下 ,轴流转桨式水轮机导叶开度与桨叶转角有着最优的配合关系 ,即协联关系 ,当水头变化时 ,此协联关系曲线也随着变化 ,因此实时跟踪水头变化是必要的 ,通过研究转桨式水轮机的协联特性 ,设计研制了天桥水电厂水头自动跟踪装置 ,使水轮机运行保持在协联工况 ,并对这一协联控制系统进行研究 .     

考虑水力振动特性求取转桨式水轮机的协联关系

在确定转桨式水轮机协联关系时,往往只考虑水轮机的能量特性。本文结合石家庄混合蓄能水电厂中的轴流转桨式水轮机协联关系的试验过程,研究了在考虑水轮机水力振动特性的情况下,应用多目标优化方法,确定转桨式水轮机协联关系。这种综合考虑水轮机的能量特性和振动特性,确定转桨式水轮机最佳运行方式的方法,为保证转桨式水轮机的高效稳定运行提供了新的途径。     

考虑水力振动特性求取转桨式水轮机的协联关系

在确定转桨式水轮机协联关豕时，往往只考虑水轮机的能量特性。本文结合石家庄混合蓄能水电厂中的轴流转桨式水轮机协联关系的试验过程，研究了在考虑水轮机水力振动特性的情况下，应用多目标优化方法，确定转桨式水轮机协联关系。这种综合考虑水轮机的能量特性和振动特性，确定转桨式水轮机最佳运行方式的方法，为保证转桨式水轮机的高效稳定运行提供了新的途径。     

葛洲坝水力发电厂PLC机组Q、W、H、η监测系统

基于可编程序控制器的机组Ｑ、Ｗ、Ｈ、η监测系统，为水轮发电机组在线监测提供了新的手段，并将机组工作水头信号自动送微机调速器，实现了轴流转桨式水轮机桨叶和导叶的自动最优协联．本文介绍了该系统的功用、组成、原理、软件框图和应用前景．     

安谷电站巨型轴流转桨水轮机制造技术研究

本文介绍安谷轴巨型流转桨水轮机结构特点以及关键零部件加工工艺,概述水轮机导水机构及转轮装配的工艺过程及质量控制方法.     

轴流转桨式水轮机机组性能测试分析

轴流转桨式水轮机的轮叶是将水的动能和势能转换为机械能的重要部件。当更换水轮机轮叶时, 机 组的整体性能会发生改变, 因此需要对其出力和振动情况进行测试。对更换新轮叶后的水轮机组各部位的振动、 摆 动进行了稳定性试验, 检验了机组运行的动平衡质量以及水轮机动态特性, 校验了最大负荷能力。测试结果表明, 在试验水头下, 机组能够在额定功率下安全稳定运行。     

葛洲坝水力发电厂PLC机组Q,W,H,η监测系统

基于可编程序控制器的机组Ｑ、Ｗ、Ｈ、η监测系统，为水轮发电机组在线监测提供了亲折手段，并将机组工作水头信号自动送微机调速器，实现了轴流转桨林水轮机桨叶和导叶的自动最优协联，本文介绍了该系统的功能，组成，原理，软件框图和应用前景。     

搅拌器内部二维流场数值模拟

采用FLUENT软件对搅拌器内部流动情况进行了二维数值模拟,研究了不同桨叶直径、桨叶转速和桨叶数对搅拌器内部流场的影响.结果显示:在同一工况下,桨叶直径为600 mm的搅拌效果比桨叶直径为400 mm和500 mm的搅拌效果好;桨叶转速为6rad/s的搅拌效果比桨叶转速为2rad/s和4rad/s转速效果好;八叶桨式搅拌器的搅拌效果较四叶桨式搅拌器和六叶桨式搅拌器稍好.模拟证实搅拌器桨叶直径、桨叶转速和桨叶数的增加有利于搅拌的混合均匀,但桨叶直径和桨叶数的增加使得搅拌器桨叶加工复杂,生产成本提高;桨叶转速也受制于搅拌器和搅拌轴的结构尺寸,不能无限增大.所以需要综合考虑各种因素的影响,才能选出最合适最经济的桨叶直径、转速和桨叶数.     

轴流转桨式水轮机轮叶自适应控制及装置实现

本文提出了实现轴流转桨式水轮机轮叶自适应控制的数字化方法——步长递减循环搜索法,介绍了以微机为主体的轮叶自适应控制装置。现场试验结果表明,该装置的软件、硬件功能,控制精度以及抗干扰性能都达到了预期效果。     

Pressure fluctuation propagation of a pump turbine at pump mode under low head condition

Pressure fluctuation at the vaneless space and vanes passages is one of the most important problems for the stable operation of a pump turbine.The fluctuation appears in any operating condition.Much research has been done on the pressure fluctuation of hydraulic machinery.However,the details of pressure fluctuation propagation of the pump turbine at the pump mode have not been revealed.The modern pump turbine with high water head requires the runner to be"flat",which would induce pressure fluctuation more easily than the low head pump turbine.In this article,a high head pump turbine model is used as the research object.As the pressure fluctuation at off-design point is more serious than at the design point,the low head condition is chosen as the research condition.Pressure fluctuation at the vaneless space and vanes passages is predicted by the computational fluid dynamics method based on k-?shear stress transport model.The experiment conducted on the test rig of the Harbin Institute of Large Electrical Machinery is used to verify the simulation method.It proves that the numerical method is a feasible way to research the fluctuation under this operating condition.The pressure fluctuation along the passage direction is analyzed at time and frequency domains.It is affected mainly by the interaction between the runner and vanes.In the circumferential direction,the influence of the special stay vane on the pressure fluctuation is got.The amplitude in the high-pressure side passage of that vane is lower than that in the other side.The study provides a basic understanding of the pressure fluctuation of a pump turbine and could be used as a reference to improve the operation stability of it.     

水泵水轮机泵工况小流量波动特性

为了研究水泵在水轮机泵工况小流量下的流场特性,对某电站水泵水轮机进行建模.采用SIMPLEC算法和剪切压力传输模型（SST k-ω）模拟泵工况的流场特性,分析当泵工况活动导叶处于设计开度时在小流量下转轮、导叶的流场,结合实验对水泵水轮机的性能进行对比计算.结果显示,在导叶设计开度下当体积流量为设计流量的15%～53%时扬程曲线有小幅度波动;流量越小在导叶间的类似射流现象越明显,随着流量降低涡结构逐渐增多并且尺度逐渐变大,以至于充满整个活动导叶与固定导叶之间的流域;导叶的存在是小流量下扬程小幅度波动的主要原因.以上结论均可为水泵水轮机的优化设计提供依据.     

气液两相多级液力透平的全流道数值模拟

以DG85-80五级节段式离心泵做液力透平,基于CFD软件,采用N-S方程和标准κ-ε湍流模型,选择Mixture多相流模型,利用SIMPLE算法,对其在纯水介质和气液两相介质时进行全流道数值模拟,得到透平的外特性曲线和内流场规律。结果显示:气液两相透平在最优工况点的压头、功率比纯水透平的高,而水力效率和质量流量较纯水透平的低;在最优工况点,随着级数增加,气液两相透平各级导叶、叶轮进出口压差增大,其内部压力分布的不均匀性增加,叶片工作面进口附近的漩涡区域减小;与小流量时的透平相比,大流量时透平各级叶轮、导叶内部的气体体积分数较大,透平叶轮出口附近的高含气率区域较小,各流道中气体分布的不对称性加剧。       

Design and study on variable nozzle mixed-flow turbocharger

A spatial motion mechanism was designed which could make all the nozzle vanes rotate a- round the center of ball with the same radius synchronously to realize control of the variable nozzle mixed-flow turbocharger （VN-MT）. The back and abdomen of the nozzle vane was designed as arc- shaped. A variable nozzle ring perfectly combined with the mixed-flow turbine was made available. The turbine geometric model of VN-MT was established through the computational fluid dynamics （CFD）. Compared with nozzleless mixed-flow turbine, the flow range of variable nozzle mixed-flow turbine was broadened tremendously while the peak turbine efficiency point was lower slightly. Flow field analysis in turbine stage showed that the energy was larger and the blade load of rotor was lower than loss of the VN-MT under designed condition the nozzleless mixed-flow turbocharger.     

基于CFD的水泵水轮机压力脉动分析

针对水泵水轮机的压力脉动问题,采用计算流体力学进行了全流道数值分析。在活动导叶以及转轮之间的无叶区沿圆周方向设置61个监测点,并且对水轮机工况以及水泵工况分别采取不同工况进行压力脉动分析,对比分析不同工况的流场与压力脉动之间的联系。结果表明,水轮机工况以及水泵工况无叶区压力在时空尺度上均呈现周期性分布,水轮机工况压力分布主要由转轮叶片所决定,水泵工况压力脉动主要由活动导叶决定。水泵工况压力脉动强于水轮机工况。     

Numerical simulation of 3D viscous flow field of air cooled turbine blades with coolant mixing

To improve thrust and reduce oil consumption of aero-engines, the temperature at turbine inlet is becoming higher and higher, which leads to heavy thermal load of vanes. To efficiently cool the vanes, the mass of coolant with its maximum gas mass flow exceeding to 20% of main stream, has to be increased. In the pres- ent paper, a two-stage turbine with and without coolant mixing was simulated by CFX-TASCflow. Simulation resuits indicate that the flow field structure with coolant is obviously different from that without coolant, and the former has characteristics of lower-speed main flow, reduced mach number, weaker shock intensity and decreased stage efficiency.     

水轮机空化系数的动态测定

水轮机叶片上的空化空蚀破坏造成水电站的频繁检修,利用计算流体力学软件Fluent对HL240型水轮机的设计工况进行数值模拟,模拟结果求出的空化系数与模型试验非常吻合。在一定的时段对机组的运行工况进行数值模拟,利用模拟结果可得到该时段叶片各个区域上的空化系数,从而判断该区域是否发生空化空蚀。把不同时段的结果进行汇总,则可以得到整个叶片上发生空化空蚀的总区域和各区域发生空蚀破坏的程度,从而对水轮机何时进行检修提供理论指导,使水电站经济效益达到最大化。