大型低扬程泵与泵装置特性预测

Performance Prediction for Large Low-head Pump and Pumping Installation

针对大型低扬程泵站广泛采用的轴流泵和导叶式混流泵两类泵型,通过对泵内损失相似性的分析,从理论上建立了水泵机械效率、水力效率、容积效率及泵和泵装置总效率表达式,并采用最小二乘法对模型泵性能试验数据进行拟合求取泵的效率常数。所推导泵和泵装置的效率公式同时考虑了泵内形状阻力损失、摩擦阻力损失和冲击损失的影响,能够很好地适应泵和泵装置在设计工况点和非设计工况点的效率换算,从而可以较准确地预测原型泵装置的动力特性。

In allusion to axial flow pump and mixed-flow diffuser pump that are widely used in large low-head pump stations, the formulas for mechanical efficiency, hydraulic efficiency and volumetric efficiency of pump were given academically by analyzing the similitude of the loss in pumps. New efficiency formulas of pump and pump system were deduced. The coefficients for efficiency of pump have been obtained by using least square method to fit the experimental data of model pump performance. The losses related to shape, hydraulic friction and strike inside pumps were all considered in the efficiency formulas and the conversion methods, so they could be well applied to the design and off-design condition. Thereby the dynamical performance of prototype pumping installation could be well and truly predicted.