变转速工况下离心泵蜗壳辐射噪声变化规律的数值研究

发布时间：2018-12-14 18:34

【摘要】：以大涡模拟得到的泵内全三维非稳态流场为基础,通过设置外部监测点对声压信号进行频域分析的方法,以额定转速为1 450 r/min的离心泵为对象,基于FW-H声学模型研究了转速在1 000~6 000 r/min变化时泵内蜗壳辐射噪声的变化规律,揭示了辐射噪声与转速之间的响应关系,通过对蜗壳压力脉动强度和流场均匀性指标的分析研究,获得了转速对辐射噪声影响的根本原因。模拟结果表明:蜗壳辐射噪声随叶轮转速的增加而非线性单调增大,且在2 000~2 500 r/min的转速区间(占总区间10%)内,蜗壳辐射噪声急剧增大(增量约为额定工况噪声7%)。同时,蜗壳辐射噪声整体上呈现指向性分布,即‘正对隔舌噪声大、背对隔舌噪声小’的偏心分布。该结论可为离心泵变频运行中有效避开高辐射噪声工况提供指导,为低噪声离心泵的三维设计奠定基础。
[Abstract]:Based on the whole 3D unsteady flow field in the pump obtained by large eddy simulation, the sound pressure signal is analyzed in frequency domain by setting external monitoring points. The centrifugal pump with rated speed of 1 450 r/min is taken as the object. Based on the FW-H acoustic model, the variation law of the volute radiation noise in the pump is studied when the rotational speed changes at 1 000 ~ 6 000 r/min, and the response relationship between the radiation noise and the rotational speed is revealed. Based on the analysis of pressure pulsation intensity and flow field uniformity of volute, the fundamental cause of the effect of rotating speed on radiation noise is obtained. The simulation results show that the volute radiation noise increases monotonously with the increase of impeller speed, and is within the speed range of 2 000 ~ 2 500 r/min (10% of the total speed range). The radiation noise of volute increases rapidly (increment is about 7% of rated noise). At the same time, the radiation noise of the volute has a directional distribution, that is, the eccentric distribution of the noise from the right side of the tongue is large and the noise from the back to the tongue is small. The conclusion can provide guidance for avoiding the high radiation noise condition effectively in the frequency conversion operation of centrifugal pump and lay a foundation for the 3D design of low noise centrifugal pump.
【作者单位】：山东大学能源与动力工程学院;胜利发电厂;
【分类号】：TH311

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