弯管安装角对管道泵内压力脉动影响的数值研究

Numerical study on influence of elbow installation angle on pressure fluctuation in pipeline pump

为了深入探究进流弯管与蜗壳相对周向位置对离心泵内水力激振的影响及其流动机理,选取立式管道离心泵为研究对象,通过对原型泵进水弯管周向安装角度的调整,衍生出6组新管道泵,并依次进行非定常数值计算.在数值计算过程中,主体监测叶轮域内压力脉动,对比分析6款新泵与原型泵的压力脉动特征,结果表明:在叶轮进口流域,当周向安装角φ=45°时,压力脉动在时域上产生了较明显的波峰相位提前,与二次流涡对激励的波谷有相互抵消作用,削弱波峰,最大降幅可达40.6%.在叶轮中段流域,安装角φ对叶片背面的压力脉动影响较大.在叶片尾缘附近流域,不同弯管安装角产生的影响沿流道从叶轮进口至叶片尾缘逐渐减小殆尽.研究结果为管道泵的实际安装及优化提供一定的参考.

To explore the influence of the relative circumferential position of the inlet elbow and volute on the hydraulic excitation in the centrifugal pump,a vertical centrifugal pipeline pump with elbow suction chamber was taken as the research object,and six groups of pump models with different circumferential installation angles were refitted based on the research object for numerical simulation.During the numerical calculation,the main body monitors the pressure fluctuation in the impeller region,and then the pressure fluctuation characteristics of the refitted pumps and the prototype pump in the impeller rotating region were compared and analyzed.The results show that in the inlet basin of the impeller,whenφ=45°,the peak phase is advanced obviously in time domain,which counteracts with the trough of secondary vortex pair excitation and weakens the peak,with the maximum decrease of 40.6%.In the middle part of the impeller,the installation angle has a great influence on the pressure fluctuation at the back of the blade.In the blade trailing edge,the influence of different elbow installation angle decreases from impeller inlet to blade trailing edge.This study can provide some reference for the actual installation and optimization of pipeline pump.