叶片交错布置对双吸离心泵外特性的影响

Effects of the staggered blades on the performance of double-suction centrifugal pump

基于RANS方程、修正后的RNG湍流模型和壁面函数法,采用CFX软件分别对交错布置和对称布置叶片的高转速低比转速双吸离心泵进行了流场为三维不可压缩湍流流场的数值模拟,计算得到了各自的性能曲线以及叶片和蜗壳内的压力和速度分布。通过对比分析可知,采用交错布置叶片能有效降低泵的轴功率,且在设计工况和大流量工况提高泵的效率,能明显改善蜗壳内部流动特性,有效减小泵内气蚀的严重程度,增强离心泵的运行稳定性。

Based on RANS equations, the amended RNG k-e turbulent mode and wall function, two double-suction centrifugal pumps work at high rotational speed and low specific speed were simulated by CFX. Two pumps were different at the blade set. One of them is staggered blades, while the other set is symmetrical blades. The fluid is assumed as three-dimensional incompressible turbulent flow. The characteristic performance curves of two pumps were predicted according to the calculated results, as well as the pressure and velocity distributions in the impeller and volute. It is shown that the staggered blades effectively reduced the shaft power of pump, enhanced the efficiency under designed and large flow rate conditions, improved the flow characteristic of the volute, reduced the severity of cavitation and improved the operation operability of the pump.