双进口两级双吸离心泵过渡流道压力脉动特性研究

发布时间：2018-05-11 08:28

本文选题：两级双吸离心泵 + 双进口　；参考：《农业机械学报》2017年02期

【摘要】：双进口两级双吸离心泵的过渡流道由正流道、过桥段、反流道3部分组成,其中正流道为双蜗壳型式,反流道为带有导叶的双螺旋型式,过桥段连接正反流道呈现空间扭曲状。过渡流道与首级叶轮和次级叶轮均存在动静耦合关系,由此导致的动静干涉效应是引起压力脉动的主要根源之一。采用CFD方法对双进口两级双吸离心泵典型工况下的三维非定常流场进行了研究,对过渡流道压力脉动机理进行了分析。研究发现,正流道内的静压分布与其双蜗壳型式密切相关,在所有工况下均呈180°对称分布,压力脉动主频均为叶片通过频率,最大脉动幅值均出现在隔舌附近;小流量工况下,隔舌处压力脉动主频幅值明显高于设计工况,约为设计工况的180%。在过桥段中,所有工况下压力脉动主频均为叶片通过频率,设计工况下,沿着流动方向,内壁面进口处的压力脉动主频幅值达到最大,外壁面主频脉动幅值变化沿流动方向有增加的趋势;在反流道中,设计工况下压力脉动主频为叶片通过频率,幅值沿着流动方向逐渐增加,出口处主频的脉动幅值约为进口处的110%;小流量工况下,反流道导叶附近存在低频成分,且在导叶周围发现具有周期性的漩涡。
[Abstract]:The transition passage of double inlet two-stage double suction centrifugal pump consists of three parts: normal passage, bridge passage and backflow channel. The normal passage is a double volute type, the reverse channel is a double helical type with a guide vane, and the connecting positive and negative passage of the bridge has a space twist shape. There is a dynamic and dynamic coupling relationship between the transition channel and the first impeller and the secondary impeller, which is one of the main causes of pressure fluctuation. Three-dimensional unsteady flow field of double-inlet two-stage double-suction centrifugal pump under typical conditions was studied by CFD method. The mechanism of pressure pulsation in transition channel was analyzed. It is found that the static pressure distribution in the positive flow channel is closely related to its double volute type, and the distribution of pressure pulsation is 180 掳symmetry under all working conditions. The main frequency of pressure pulsation is blade passing frequency, and the maximum pulsation amplitude appears near the tongue. The main frequency amplitude of pressure pulsation in the tongue is obviously higher than that in the design condition, which is about 180 parts of the design condition. In the bridge section, the main frequency of pressure pulsation is the blade passing frequency under all working conditions. Under the design condition, the amplitude of the main frequency of pressure pulsation at the inlet of the inner wall reaches the maximum along the flow direction. The amplitude of the main frequency pulsation on the outer wall increases along the flow direction, and in the backflow channel, the main frequency of the pressure pulsation is the blade passing frequency, and the amplitude increases gradually along the flow direction. The pulsation amplitude of the main frequency at the outlet is about 110 at the inlet, and the low frequency component is found near the guide vane of the backflow channel under small flow conditions, and periodic swirls are found around the guide vane.
【作者单位】：中国农业大学大学水利与土木工程学院;北京市供水管网系统安全与节能工程技术研究中心;上海连成集团有限公司;
【分类号】：TH311;;TV131.3+3

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