大型立式轴流泵变频反向发电压力脉动特性分析

Analysis on the pressure pulsation characteristics of large-scale vertical axial flow pump with rotation frequency inverted power generation

为研究水泵在反转发电时,转速对水泵性能的影响,对水泵在变频反向发电工况下进行全流道数值模拟.可知:水泵在进行反向变频发电时,流线较一般水轮机流线图分布差,出转轮部分水流出现絮乱;压力脉动幅值在出转轮处最大,进转轮处次之,进导叶时最小,最大压力脉动系数为0.56,约为进转轮的20倍.压力脉动幅值沿转轮中心向转轮边缘逐渐增大,边缘处压力脉动系数约为转轮中心处的8倍;水流受转轮转动影响严重,进出转轮截面水流压力脉动主频为叶频,次频为转频.

In order to study the influence of the rotational speed on the performance of the pump when the pump was in inverted power generation,the full - flow numerical simulation of the pump under the condition of rotation frequency inverted power generation was carried out. It was concluded that the distribution of flow line was worse than that of general turbine when pumps generate electricity by reverse frequency conversion,and the flow of the outlet runner was confused. The pressure pulsation amplitude was the largest at the rotor,the second at the runner,and the smallest when entering the guide vane. The maximum pressure pulsation coefficient was 0. 56,which was about 20 times that of the runner. The pressure fluctuation amplitude increased gradually along the center and the edge of the runner,and the pressure fluctuation coefficient at the edge was about 8 times that at the center of the runner. The flow was seriously affected by the rotation of the runner. The main frequency of pressure pulsation in and out of the runner section was blade frequency,and the secondary frequency was rotation frequency.