大流量低扬程水泵无叶区非定常流动特性研究

Study of non-constant flow characteristics in the vaneless zone of high-flow and low-head pump stations

本文是东方电机为珠江三角洲水资源配置工程的鲤鱼洲和高新沙泵站开展水力开发的部分工作,主要研究水泵在最优工况和大流量工况无叶区的非定常流动特性,为泵站的稳定运行提供依据。非定常计算结果显示,无叶区压力脉动主要受动静干涉影响,脉动幅值较小(最优工况不高于4%,大流量工况不高于7%),因此满足工程稳定运行需求。压力脉动主要频率是叶片通过频率及其倍频(7倍转频及其倍频)。相比于最优工况点,大流量工况点转轮出口的速度沿周向的分布更复杂,因此压力分布也复杂,压力脉动幅值也更大。本文的计算结果与模型试验结果比较吻合,从而说明计算的可靠性。

This paper is part of the hydraulic development work of Dongfang Electric for the Liyu Zhou and Gao Xinsha Pumping Station of the Pearl River Delta W ater Resources Allocation Project.The main study is based on the unsteady flow characteristics of the pump in the vaneless zone at the optimal and high-flow conditions,which provides a basis for the stable operation of the pumping station.The unsteady calculation results show that the pressure pulsation in the vaneless zone is mainly affected by the dynamic and static interference,and the pulsation amplitude is small(not higher than 4%in the optimal condition and not higher than 7%in the high-flow condition),so it meets the demand of stable operation of the project.The main frequency of pressure pulsation is the blade through frequency and its multiplier(7 times the frequency of rotation and its multiplier).Comparing with the optimal operating point,the velocity distribution along the circumferential direction of the runner outlet at the high flow operating point is more complicated,so the pressure distribution is also complicated,and the pressure pulsation amplitude is also larger.The calculation results in this paper are in good agreement with the model test results,thus illustrating the reliability of the calculation.