超高水头水泵水轮机甩负荷导叶关闭规律分析

为研究导叶关闭规律对超高水头水泵水轮机甩负荷的影响,以敦化电站为例,定性分析了超高水头大容量高转速蓄能机组的过流特性;在过流特性曲线分析的基础上,采用一段直线、延时直线及传统两段的三种导叶关闭规律对该电站进行大波动过渡过程计算分析。计算结果表明,关闭规律的选取对过流特性的依赖性强,该特性对过渡过程各参数值的影响较大;延时直线关闭可有效降低蜗壳进口压力,虽机组转速会小幅度上升,但在可控范围内,对尾水管进口最小压力没有积极作用;两段关闭中折点位置和时间的选择在平衡蜗壳进口压力和尾水管进口压力方面很关键。研究成果对高水头蓄能电站导叶关闭规律的选择具有借鉴意义。

Analysis of Closing Law of Guide Vane of Load Rejection for Ultra-High Head Reversible Unit

In order to study the influence of the guide vane closing law of load rejection for ultra-high head reversible unit, the over-flow characteristics of high-head high-capacity high-speed reversible units were analyzed qualitatively by taking Dunhua power station as an example. Based on the analysis of the over flow characteristic curves, the transient process of large fluctuation of the power station is analyzed by the straight line, delay line and two-segment closing law. The calculation results show that the selection of the closing law is highly dependent on the over flow characteristics; The delay linear closing law has a significant effect in reducing the inlet pressure of the spiral case. Although the unit speed will increase slightly, it is within the controllable range, and has no positive effect on the minimum pressure of the draft tube inlet. The choice of the position and time of the breakpoint in the regularity is critical in balancing the inlet pressure of the spiral case and the inlet pressure of the draft tube. The conclusions obtained in this paper have reference significance for the selection of the guide vane closing law of the high-head storage power station.