灯泡贯流式水轮机压力脉动数值分析

Analysis of Numerical Values of Bulb Turbine Pressure Fluctuation

灯泡贯流式水轮机压力脉动是引起机组振动水力振动源之一.以某水电站的灯泡贯流式水轮机为基础建立三维几何模型,完成了从流道进口到尾水管出口全流道的瞬态计算,预测了导叶进口、转轮进口、转轮出口和尾水管内的压力脉动,得到压力脉动波形图,并利用FFT变换得到了压力脉动的频谱图,以此来分析灯泡贯流式水轮机压力脉动情况.结果表明在此工况下机组的压力脉动较小,机组导叶和叶片所引起的不稳定流场为压力脉动的主要原因与水电站的实际压力脉动情况基本吻合.

Pressure fluctuation of the bulb turbine is one of the waterpower vibration sources which cause the unit vibration.Based on the bulb turbine of a hydropower station,the three-dimensional geometric model was constructed,the transient calculation of the whole flow passage from the channel inlet to the draft tube was made,the pressure fluctuation of the guide vane inlet,the runner inlet and outlet,and the draft tube was predicted,and the waveform graph and spectrogram of pressure fluctuation were obtained.The analysis of pressure fluctuation of the bulb turbine showed that the major causes of pressure fluctuation are the unsteady flow field caused by guide vanes and blades of the bulb turbine,which is basically consistent with the actual pressure fluctuation of the hydropower station.