【摘要】 对离心泵而言,叶轮时序位置的改变对泵水力性能和压力脉动影响较大。本文对某两级离心泵首级和次级叶轮在七种不同时序位置下的内部流动进行了数值模拟,并对叶轮和蜗壳内部的流场和压力脉动特性进行了分析。结果表明:在设计流量下随着次级叶轮时序位置的变化,离心泵的扬程和效率分别上升了2.9%和2.4%;同时时序位置的改变影响了叶轮进口相对液流角和出口环量,改善了蜗壳隔舌处的流态,漩涡区域减小,从而降低了次级叶轮和蜗壳内部的流动损失;时序效应对次级叶轮和蜗壳压力脉动影响较大,各测点主频均无变化,但次级叶轮内测点压力脉动主频幅值降低了20.16%,蜗壳隔舌处降低了2.24%。综合比较分析不同时序位置下两级离心泵的性能,当次级叶轮旋转至首级叶轮流道中间时,离心泵的水力性能及压力脉动特性较好,研究结果可为两级离心泵设计提供参考。更多还原

【Abstract】 The impeller clocking position has a great influence on the hydraulic performance and pressure pulsation for a two-stage centrifugal pump. In order to discuss the effect of the clocking position of the first and secondary impeller on the internal flow of the two-stage centrifugal pump, a two-stage centrifugal pump was applied to simulate the steady and unsteady inner flow field when the secondary impeller at seven different clocking positions was under design conditions. Through the analysis of the flow field and pressure pulsation characteristics in the impeller and volute, it is shown that the head and efficiency of the multistage pump are increasing with the increase of the clocking position angle. The head of the C₃ is 2.9% higher and the efficiency 2.4% greater than C₀. The clocking affects the inlet relative flow angle and outlet circulation of impeller, improves the flow pattern at the volute tongue and reduces the flow loss in the secondary impeller and volute. The clocking position has a great influence on the pressure pulsation of the volute and secondary impeller. The amplitude of the main frequency decreases gradually. Compared with the C₀, the main frequency amplitude is reduced by 20.16% and 2.24% respectively. A comprehensive comparison and analysis of the performance of two-stage centrifugal pumps are made under different clocking position, and the hydraulic performance and pressure pulsation characteristics of the centrifugal pump is better at C₃, with the research results providing a reference for the design of two-stage centrifugal pump.更多还原