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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。
Pump Suter curve is one of the prerequisites for pumping station water hammer analysis. The existing methods for obtaining Suter curves of double suction centrifugal pumps are difficult and costly. However, the accuracy of indirect interpolation estimation methods is relatively low. In this paper, a three-dimensional numerical calculation of pump suction flow is used to determine the double suction centrifugal pumps Suter curve of the new method, referred to as three-dimensional characteristics of the law. The method uses computational fluid dynamics (CFD) technology to perform three-dimensional modeling, working condition dispersion, flow field calculation and result transformation of a double-suction centrifugal pump to quickly and accurately obtain the Suter curve of a double-suction centrifugal pump. Working conditions, the turbine working conditions, reverse turbine conditions, reverse pump conditions and other conditions, calculate the corresponding flow, speed, lift and torque relationship. Quantitative analysis shows that the computational accuracy of Wh (x) is improved by 39.2% on average and the computational accuracy of Wb (x) is improved by 26.3% on average in the Suter curve obtained by the three-dimensional intrinsic method compared with the indirect interpolation estimation method. The suter curve of the double-suction centrifugal pump obtained by this method was used in the waterhammer analysis of accident stop-pump conditions, the calculated maximum pressure of the system was reduced by 15.0%, the pressure range of pipeline was reduced by 81.4%, double suction centrifugal pump The maximum reverse flow increased by 11.9%, the maximum reverse speed decreased by 6.1%, with the actual test results closer. The method provides a new technical approach to improve the accuracy of water hammer analysis of double suction centrifugal pump station.