三峡左岸电站VGS 机组真机与模型压力脉动对比分析

为了解真机在不同运行水头下的压力脉动、振动、摆度与噪声等稳定性参数及水轮机效率,分析真机实测试验结果与模型试验结果的相互关系,划分机组稳定运行区域和指导机组优化运行,三峡水力发电厂于2006年开展了135～156m升水位机组稳定性与能量性能试验.本文就升水位过程8F机组(VGS)压力脉动作了详细分析,发现模型试验中出现的高部分负荷特殊压力脉动带在升水位(141～155m)真机试验中不明显,在升水位过程,真机在特殊压力脉动带的幅值有增大的趋势但增幅很小,主频也与模型不一致,模型试验结果约为2倍和4倍转频,而在真机中是0.3Hz的尾水管涡带频率.

Analysis and comparison between prototype and model of VGS unit in the left bank of Three Gorges Hydropower Plant

In order to find out the characteristics of pressure pulsation,vibration,swing,noise and turbine efficiency of prototype unit under different heads,to analyze the relationship between prototype and model,to plot out a unit stable running domain and to make instruction for unit optimized operation,a series of tests of stability and energy performance were carried out under conditions of the upper water level rising from 135m to 156m in the Three Gorges Hydropower Plant in 2006.Pressure pulsation of VGS unit during upper water level rising was analyzed in detail in this paper.The relationship between prototype and model performance was analyzed.It revealed that a high pulsation band occurring in model test did not appear in prototype test.The basic frequency of the model unit was different from that in prototype.