水泵Suter曲线是泵站水锤分析的必备条件之一。现有用于获取双吸离心泵Suter曲线的实测法具有难度大、成本高的特点,而间接插值估算法的精度又比较低,本文提出了一种通过水泵流场三维数值计算确定双吸离心泵Suter曲线的新方法,简称三维内特性法。该方法采用计算流体力学(CFD)技术,对双吸离心泵的水力模型进行三维造型、工况离散、流场计算及结果转化,以快速、准确地获取双吸离心泵Suter曲线,在正水泵工况、正水轮机工况、反水轮机工况、反水泵工况等工况下,计算出相应流量、转速、扬程和转矩关系。定量分析表明,相比于间接插值估算法,采用三维内特性法获得的Suter曲线中,Wh(x)的计算精度平均提高了39.2%,Wb(x)的计算精度平均提高了26.3%;在将采用该方法获得的双吸离心泵Suter曲线用于事故停泵工况水锤分析时,计算得到的系统最大压力降低了15.0%,管线发生汽化压力的范围缩减了81.4%,双吸离心泵的最大倒流量增大了11.9%,最大倒转速降低了6.1%,与实际测试结果更为接近。该方法为提高双吸离心泵站水锤分析精度提供了一种新技术途径。
The Suter curves of pump are the primary parameters for water hammer analysis in a pump sta-tion. The existing measurement method to obtain the Suter curves of double-suction centrifugal pump hasthe characteristics of high difficulty and cost, and the other method of indirect interpolating estimation hasthe low accuracy performance. In order to get the Suter curves of double-suction centrifugal pump quicklyand accurately,a three-dimensional internal characteristics method is presented based on computational flu-id dynamics(CFD) technology. This method includes three-dimensional modelling,setting of operation con-ditions, numerical simulation on flow field and transformation of results. The core of this method is thatthe relationship among flow discharge, speed, head and torque is calculated accurately by CFD technologyin pump operation condition,turbine operation condition,reverse pump operation condition,reverse turbineoperation condition and four brake operation conditions. It is indicated that average accuracy of Wh(x) andWb(x) are improved by 39.2% and 26.3% respectively by means of the proposed three-dimensional internalcharacteristics method, compared with interpolating estimation method. Moreover, the predicted maximumpressure is reduced by 15.0%, the pipeline scope of vapour pressure occurrences is narrowed by 81.4%,the resulted maximum reverse discharge through pump is increased by 11.9%,and the maximum reverse ro-tating speed is decreased by 6.1%. This method could be used as a new approach to improve the accuracyof water hammer analysis in a double-suction centrifugal pump station.