基于弱可压缩的水泵水轮机S区压力脉动分析

发布时间：2018-04-24 13:57

本文选题：水泵水轮机 + 流场　；参考：《水力发电学报》2017年06期

【摘要】：高水头水泵水轮机S特性会导致其在水轮机工况并网困难,严重时会引起机组的振动,对电站的安全稳定运行产生不利影响。为了研究水泵水轮机S特性工作区域的压力脉动情况,本文以国内某抽水蓄能电站水泵水轮机为研究对象,对水泵水轮机内部流动进行了全流道定常和非定常数值模拟,并分析了其稳定工况、小转矩工况、小流量工况以及反水泵工况无叶区和尾水管内的压力脉动特性。结果表明:S特性区静压波动比较大;在活动导叶与转轮之间的无叶区,考虑可压缩性的主频均为叶片通过频率,而不考虑可压缩性时,小转矩工况的主频为2倍频;考虑可压缩性的幅值稍大,但无论是否考虑可压缩性,特征幅值都是随着单位流量的减小先增大后减小,同时该区域14fn和21fn等高频压力脉动的幅值较小;尾水管内压力脉动的主频为fn、3fn和4fn,稳定工况的幅值最小,弯肘段和出口段其他工况的幅值为稳定工况的十几倍,与回流涡结构有关。
[Abstract]:The S characteristic of high head water pump turbine will lead to the difficulty of grid connection in the working condition of the turbine, and will cause the vibration of the unit when it is serious, which will have an adverse effect on the safe and stable operation of the power station. In order to study the pressure pulsation in the S characteristic working area of a pump turbine, the steady and unsteady flow inside the pump turbine is simulated with a pump turbine of a pumped storage power station in China. The characteristics of pressure ripple in the stable condition, the small torque condition, the small flow condition, the vaneless area of the backwater pump and the draft tube are analyzed. The results show that the static pressure fluctuates greatly in the characteristic region of: s, and in the vaneless region between the active guide vane and the runner, the main frequency considering compressibility is the blade passing frequency, but the main frequency of the small torque condition is 2 times when the compressibility is not taken into account. The amplitude of compressibility is slightly larger, but whether or not compressibility is considered, the amplitude of characteristic amplitude increases first and then decreases with the decrease of unit flow rate, and the amplitude of high frequency pressure fluctuation such as 14fn and 21fn in this region is smaller. The main frequency of pressure pulsation in draft tube is fnn 3fn and 4fn, the amplitude of steady working condition is the smallest, and the amplitude of bending elbow and outlet section is more than ten times of that of steady working condition, which is related to the structure of reflux vortex.
【作者单位】：西安理工大学水利水电学院;
【基金】：国家自然科学基金(51679196;51179152;51339005;51379174;51279260)
【分类号】：TV743

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