前后盖板长度对离心泵外特性与非定常特性的影响

发布时间：2018-04-18 20:37

本文选题：离心泵 + 切削叶轮　；参考：《灌溉排水学报》2017年08期

【摘要】：为了研究前后盖板保留长度对离心泵外特性以及非定常特性的影响,以一台比转速为80的离心泵为研究对象,在切削叶轮的叶片外径保持不变的情况下,对比了不同前后盖板直径(168、174和180 mm)对外特性、径向力和压力脉动的影响。通过对离心泵进行全流场非定常计算发现,各流量下扬程、效率均随前后盖板保留长度的增加而增大,扬程最大相差2.14 m,效率最大相差3.5%;在设计工况下,3种方案下的径向力呈周期性变化,矢量图呈五芒星分布,前后盖板保留得越多,径向力越大;由于叶轮与隔舌动静干涉的作用,蜗壳内各监测点压力脉动的主频均为叶频,随着叶轮与蜗壳间间隙的减小,隔舌处的压力脉动在叶频处基本保持不变,其倍频逐渐增大,第二断面的压力脉动系数幅值也逐渐增大。
[Abstract]:In order to study the influence of the retaining length of the front and rear cover plate on the external and unsteady characteristics of the centrifugal pump, a centrifugal pump with a specific speed of 80 is taken as the research object, while the outer diameter of the blade of the cutting impeller remains unchanged.The external characteristics, radial force and pressure pulsation of different front and rear cover plates with different diameters (168174 and 180 mm) were compared.Through the unsteady calculation of the whole flow field of the centrifugal pump, it is found that the lift and efficiency increase with the increase of the retaining length of the front and rear cover plates under each flow rate.The maximum lift difference is 2.14 m, and the maximum efficiency difference is 3.5 m. The radial force varies periodically under the three schemes, and the vector diagram is a pentagram distribution, the more the front and rear cover plates are retained, the greater the radial force is.Because of the interference between impeller and tongue, the main frequency of pressure pulsation at every monitoring point in volute is blade frequency. With the decrease of clearance between impeller and volute, the pressure pulsation of tongue is basically unchanged at the frequency of impeller, and its frequency doubling increases gradually.The amplitude of pressure fluctuation coefficient of the second section also increases gradually.
【作者单位】：河北省子牙河河务管理处;河北省邯郸市涉县水利局青塔水库灌区管理处;
【分类号】：TH311

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