水泵转速变化对进出水流道水力损失的影响

Influence of Rotational Speed of Pumps on Hydraulic Losses in Suction Boxes and Discharge Passages

在比较各种进出水流道水力损失研究方法的基础上,运用计算流体动力学方法数值模拟了4种水泵装置内部流动,研究水泵转速变化对进出水流道水力损失的影响。数值计算结果表明,由于水泵装置中进水流道内部流动受水泵叶轮旋转引起的水流预旋的影响,因而小于无泵单独运行时的水力损失。水泵转速变化后,在相同流量下,进水流道的水力损失基本不变。水泵导叶出口水流条件和剩余环量影响出水流道的水力特性,水力损失随流量变化的关系非常复杂。水泵转速变化后,出水流道内部流动不相似,相同流量下的水力损失不相等。装置模型试验结果验证了数值计算结果的有效性和可靠性。

Based on the comparison of different research methods on the hydraulic losses of suction boxes and discharge passages, the computational fluid dynamics method is adopted to simulate the internal flow of four different pumping systems and to investigate the influence of rotational speed of pumps on hydraulic losses of suction boxes and discharge passages. The computed results indicate that the internal flow of suction box is affected by the pre-swirl caused by impeller rotation, the value of hydraulic loss is smaller than that when the suction box is operated solely without pump. The hydraulic loss of suction box keeps unchanged at the same flow rate when the rotational speed of pump is changed. The hydraulic characteristics of discharg residual circulation of pump diffusers. The internal e passage are influenced by the flow conditions and flow field is not conformed to the affinity law and the hydraulic loss of discharge passage is unequal at the same flow rate when the rotational speed of pump is changed. The validity and reliability of numerical computation are verified by model test results of pumping systems.