Sensitivity analysis of transient flow of two parallel pump-turbines operating at runaway
Sensitivity analysis of transient flow of two parallel pump-turbines operating at runaway
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DOI：
10.1016/j.renene.2015.08.059
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发表时间：
2016-02
期刊：
影响因子：
8.7
通讯作者：
Ali Rezghi;A. Riasi
中科院分区：
文献类型：
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作者：
Ali Rezghi;A. Riasi
水力发电厂的瞬变流分析是防止河道压力波动的重要问题之一。本文用数值方法研究了两台并联水泵水轮机在失控工况下（水泵水轮机不稳定S形区）的水力过渡过程灵敏度分析。考虑了位于伊朗北部的Siah Bishe电厂的特点。首先，模拟了两台机组在飞逸状态下的同时运行。为此目的，瞬变流的控制方程求解沿着水道使用的方法的特征和修改的苏特变换。研究了蜗壳压力上升、调压室水位振荡、转速、流量和不稳定区扭矩振荡对转动惯量、调压室联络洞水头损失系数、联络洞直径和声波波速的敏感性。结果表明，转动惯量对飞逸不稳定工况下的最大转矩有较大影响。转动惯量的增大也可以推迟压力和转速的峰值。调压室联络洞水头损失系数和联络洞直径对调压室最大水位和失控失稳工况下的最大扭矩有较大影响。通过使用不同的声波速度值，输出条件没有显示出任何明显的趋势。
Transient flow analysis in hydroelectric power plants is one of the most important issues for the prevention of undesirable pressure fluctuations in waterways. In this paper sensitivity analysis of hydraulic transient for two parallel pump-turbine units operating at runaway (unstable S-shaped zone of pump-turbine hill-chart) have been numerically investigated. The characteristics of Siah Bishe power plant located at the north of Iran, has been considered. Firstly, simultaneous operation of two units at runaway is simulated. For this purpose, the governing equations of transient flow are solved along the waterways using the method of characteristics and modified Suter transformations. Then, the sensitivity of pressure rise at the spiral case, water level oscillating at surge tank, rotational speed and flow rate and torque oscillation at unstable zone of hill-chart to moment of inertia, head loss coefficient of connection tunnel of surge tank, connection tunnel diameter and acoustic wave velocity has been performed. The results show that the moment of inertia has considerable effect on the maximum torque at unstable condition of runaway. Also, more moment of inertia can well postpone the peak of pressure and rotational speed. The maximum water level of surge tank and the maximum torque at unstable condition of runaway are strongly affected by head loss coefficient of connection tunnel of surge tank and connection tunnel diameter. By using different values for acoustic wave velocity, output conditions don't show any clear trend.