导叶对液力透平机组工作稳定性的影响

发布时间：2018-11-02 19:23

【摘要】：为了提高液力透平工作时的稳定性,降低机组的振动,在液力透平叶轮进口前添加不同数量的导叶,采用SSTk-ω湍流模型,利用FLUENT软件通过在各过流部件内设置监测点计算在不同导叶数下液力透平内的压力和压力脉动情况,然后通过快速傅里叶变换将压力脉动的计算结果进行处理,分析液力透平各过流部件内压力脉动的时域和频域分布,最后总结导叶数对液力透平机组工作时稳定性的影响规律。研究表明:当导叶数等于9时蜗壳内的压力脉动主频幅值最小;随着导叶数的增加,叶轮内的最大压力脉动幅值逐渐减小,而导叶数对尾水管内压力脉动幅值的影响较小;要提高液力透平机组的稳定性需降低液力透平内的压力脉动幅值,而通过叶轮进口前添加导叶的方法可以很好地降低液力透平内的压力脉动幅值,但导叶数不能太少也不能过多。
[Abstract]:In order to improve the stability of the hydraulic turbine and reduce the vibration of the unit, different numbers of guide vane were added before the inlet of the hydraulic turbine impeller, and the SSTk- 蠅 turbulence model was used. The pressure and pressure pulsation in hydraulic turbine with different guide vane numbers are calculated by setting monitoring points in various flow passing parts by using FLUENT software, and then the calculation results of pressure fluctuation are processed by fast Fourier transform. The time-domain and frequency-domain distributions of pressure pulsation in hydraulic turbine components are analyzed. Finally, the influence of guide vane number on the stability of hydraulic turbine unit is summarized. The results show that when the number of guide vane is equal to 9, the main frequency amplitude of pressure pulsation is minimum, and the maximum pressure fluctuation amplitude in impeller decreases gradually with the increase of guide vane number, but the influence of guide vane number on the amplitude of pressure pulsation in draft tube is small. In order to improve the stability of hydraulic turbine set, the amplitude of pressure pulsation in hydraulic turbine should be reduced, and the amplitude of pressure fluctuation in hydraulic turbine can be reduced by adding guide vane before the inlet of impeller. But the number of guide vane should not be too small or too much.
【作者单位】：西华大学能源与动力工程学院流体及动力机械教育部重点实验室;兰州理工大学能源与动力工程学院;
【基金】：国家自然科学基金资助项目(51279172) 西华大学重点科研基金资助项目(Z1510417)
【分类号】：TK05

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