大型低扬程泵站的停机过渡过程研究

Study on shutdown transition process of large low head pumping station

本文针对大型立式轴流泵停机过渡过程中可能出现的不安全因素,对具有直管式出水流道的大型立式轴流泵进行建模,采用VOF技术计算模拟,使用UDF功能模拟快速闸门关闭过程,并对现场导叶处压力脉动进行同步动态测量,以验证数值分析结果的准确性。结果表明:轴流泵机组在停机过程中会依次进入水泵工况、制动工况、水轮机工况;在快速闸门关闭后,叶片力矩与叶片轴向力会发生明显振荡,易诱发抬机事故。研究结果对泵站安全生产具有指导意义。

The large vertical axial flow pump with straight pipe outlet conduit is modeled in view of possible unsafe factors in the stop transition process of large vertical axial flow pumps. Simulation is obtained by using the VOF technique, UDF function is applied to simulate the closing process of fast gate, the pressure pulsation of the guide vane undergoes synchronous dynamic measurement, thereby verifying the accuracy of the results of numerical analysis. The results show that the axial flow pump unit in the shutdown process will successively enter the pump operating conditions, braking conditions and turbine operating conditions;After the rapid gate is closed, the blade torque and the blade axial force will shock obviously, and it is easy to induce the lifter accident. The results are of guiding significance to the safe production of pumping station.