基于流热固耦合的熔盐泵转子动力特性分析

doi:10.12034/j.issn.1009-606X.217372

摘要/Abstract

摘要： 用ANSYS软件模拟了熔盐泵转子的应力与变形，研究了不同介质流量下非定常流动对转子部件的影响，考察了泵转子结构的模态性能. 结果表明，转子温度自叶轮部件沿泵轴向轴承逐渐降低，不同介质流量下叶轮内的最大等效应力均出现在叶片进口边与前盖板的结合处，泵轴与轴承的配合处出现了明显的应力集中，转子部件的最大变形出现在叶轮边缘，且最大等效应力和变形量均随介质流量增大而减小，设计流量下转子部件最大等效应力和总变形量的变化幅度最小，添加预应力后转子部件前6阶固有频率增加，但振幅变化不大，流量对转子部件模态性能的影响较小.

关键词: 熔盐泵, 转子, 传热, 流热固耦合, 模态分析, 数值模拟

Abstract: The molten-salt pump is used to transport high-temperature membrane caustic soda, carbonate, nitrate, phthalic anhydride and other mediums in industrial loops. The temperature of the medium in the molten-salt pump is generally above 400℃. In order to study the operation stability of the pump transporting high-temperature molten salt, the stress and the deformation of the pump rotor were simulated using ANSYS commercial code. At different medium flow rates, the effect of unsteady flow on the rotor was considered. The modal performance of the rotor was investigated as well. The results indicated that static pressure increases gradually with the increase of the flow rate. The temperature in the rotor decreased gradually from the impeller to the bearings along the shaft, and the influence of temperature deserves a full consideration during the pump design in view of high temperature gradients arising at both ends of the rotor. The maximum equivalent stress in the impeller at different flow rates occurred at the junction of the blade leading edge and the front shroud. A distinct stress concentration was found at the position of the bearings. The maximum deformation in the rotor emerged at impeller outer edge. The maximum equivalent stress and deformation degraded with the increase of the flow rate. Under the design condition, both the maximum equivalent stress and rotor deformation fluctuated slightly. The first six order natural frequencies rise slightly with the introduction of pre-stress, but the change of vibration amplitude was insignificant. Furthermore, the effect of flow rate on the modal performance was negligible. The modal deformation of the pump rotor was concentrated on the impeller, which was determined by the supporting manner and operation characteristics of the pump rotor. Natural frequencies corresponding to each mode of the pump rotor deviate considerably from the blade passing frequency and its second harmonic frequency as well. Therefore, the resonance caused by hydraulic excitations will not occur for the molten-salt pump considered.

Key words: molten salt pump, rotor, heat transfer, fluid-thermal-structure coupling, modal analysis, numerical simulation

朱洋康灿李清. 基于流热固耦合的熔盐泵转子动力特性分析[J]. 过程工程学报, 2018, 18(5): 957-964.

Yang ZHU Can KANG Qing LI. Investigation of structural dynamic characteristics of molten-salt pump rotor based on fluid-thermal-structure coupling[J]. Chin. J. Process Eng., 2018, 18(5): 957-964.

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