高温熔盐泵的模态计算与分析

Modal Analysis of Molten Salt Pump at High Temperature

为了研究高温熔盐泵的运行可靠性,基于ANSYS Workbench对熔盐泵结构部件分别进行了无预应力和有预应力的模态计算。基于计算结果对熔盐泵的振动特性进行了分析,并对不同相位下转动和静止部件的固有频率和振幅的变化进行了比较。计算结果表明:无预应力时,转动和静止部件的第1阶和第2阶以及第4阶和第5阶固有频率较为接近,且同阶下,静止部件的固有频率远高于转动部件的固有频率;转动部件和静止部件各阶的固有频率均远离主要的激振频率,可有效避免共振的产生;同阶不同相位下,转动和静止部件的固有频率和振幅变化较小,叶轮相位对熔盐泵模态性能的影响可以忽略;有预应力下静止部件和转动部件的固有频率比无预应力下有小幅提升,且转动部件的增幅较高,其幅度为1.35%;转动部件的模态变形主要集中在叶轮端,而静止部件的进出水管变形更为明显。研究结果可为熔盐泵的开发与结构优化提供一定的参考。

In order to investigate the reliability of molten salt pump in running state,modal analysis of rotational and stationary parts in both none pre-stress and pre-stress states was carried out by employing ANSYS Workbench code. Based on the calculation results,the vibration performance of the pump was analyzed. Natural frequencies and amplitudes of rotational and stationary parts under different rotation phases were compared. The calculation results show the natural frequencies of the two parts in the 1st and 2nd order are close in none pre-stress state. Also,the natural frequencies of the 3rd and 4th order show the same tendency. Under the same order,the natural frequency of the stationary part is much higher than the rotational part. The first 6 order natural frequencies are far away from the main exciting frequencies,which makes the resonance less likely to happen. The natural frequency and amplitude of the two parts in the same order stay stable with the phase changing. The natural frequency in pre-stress state improves slightly compared with that in none pre-stress state. And the rotating parts enjoys a higher increase for 1. 35%. Modal transformation for rotating parts mainly concentrate near the impeller while the stationary part is more likely to lie next to the inlet and outlet pipe. The analysis results will offer a reference for the structure design and optimization of molten salt pump.