导叶开度对水泵水轮机泵工况导叶区流场影响的试验研究

针对活动导叶开度对水泵水轮机泵工况导叶区流场和模型性能的影响,在高精度模型通用试验台上对一低比转速模型水泵水轮机导叶区的流场运用粒子图像测速(PIV)系统进行了测量。测量结果显示,同一开度下随着流量减小,无叶区内的流速出现增大的趋势;同一流量随着开度的减小,导叶前流速明显增大,模型效率下降。模型试验在转轮无空化条件下进行,但在8 mm开度83%最优流量工况,由于流速高、冲角大,造成位于高压侧的导叶头部发生了明显的绕流空化现象,并引起了固定导叶流道宽频带的压力脉动。研究成果可为水泵水轮机的优化设计和安全稳定运行提供试验依据。

Experimental study on influence of guide vane opening on flow field in guide vane region under pumping mode of pump-turbine

Aiming at the influence of guide vane opening on the flow field in the guide vane region under pumping mode of pumpturbine，the flow field in the guide vane region of a low specific speed model pump-turbine is measured with the system of Particle Imaging Velocimetry ( PIV) on a high precision conventional model experiment platform. The measuring result shows that the flow velocity within the vaneless region increases along with the decrease of the flow rate under the condition that mo-cavitation occwrred on therunner. However，cavitation was found on the heed of the qwid vane wnder 8 mm opening when the flow rate is 83% of the optimal flow rate. The caritation was caused by high flow velocity and large angle of attack to the guide vane，and leads to broadband pressure pulsation in the flow passage of the stay vane. The study result can provide an experimental basis for the optimal design as well as the safe and stable operation of pump-turbine.