基于流热固耦合的高温熔盐泵转动系统结构应力分析

基于ANSYS Workbench平台开展高温熔盐泵转动系统的结构应力分析,采用计算流体动力学软件CFX对泵内部全流场进行多工况定常数值计算,并通过试验对计算结果进行验证.综合考虑了高温熔盐泵的水动力载荷、离心力载荷、温度载荷等因素,建立了流、热、固耦合作用下动力学模型,研究不同温度下不同材料属性变化对高温熔盐泵结构性能的影响,并对高温熔盐泵转子部件进行应力分析.结果表明:在同一流量工况下,不同材料的叶轮叶片最大变形量均呈随温度的升高呈先增大后减小的趋势;同时,不同材料的叶轮形变程度基本趋于稳定,受流量影响不大;叶片工作面应力值大于叶片背面应力值,且不同温度工况下不同材料的叶轮背面应力值呈线性递减的趋势;叶轮等效应力最大位置主要集中在叶轮出口处叶片和前、后盖板接触的区域;经过变形及强度综合分析,表明3种不同的不锈钢材料中316L材质的叶轮力学性能最好.研究结果可为高温熔盐泵的结构设计提供一定参考.

Structural stress analysis of rotor system of high-temperature molten-salt pump based on flow-thermal-structure coupling

The structural stress analysis in the rotor system of a high-temperature molten-salt pump was carried out based on ANSYS Workbench.At first,computational fluid dynamics software CFX was used to calculate the steady turbulent flows in the pump under multiple working condition,and the predicted results were validated with experimental data.By comprehensively considering the hydrodynamic,centrifugal and thermal loads in the high-temperature molten-salt pump,a flow-thermal-structure coupling dynamic model was established for the rotor system.Based on the model,the influence of material pro-perty and temperature on the structural performance of the pump was investigated,and the structural stress analysis in the rotor system components was conducted.The results show that under the same flow condition the maximum deformation of impeller blades in different materials shows a first increasing and then decreasing trend with increasing temperature.Moreover,the impeller deformation keeps constant basically and is less affected by flow rate.The stress level on the blade pressure side is higher than that on the blade suction side,and the stress value on the blade suction side in different materials exhibits a linearly decreasing trend at various temperatures.The position with the highest equivalent stress is mainly concentrated in the areas where the blades are in contact with the shroud and hub near the impeller outlet.Based on the comprehensive analysis on impeller deformation and strength,the impeller with stainless steel 316L is the best solid mechanics performance compared with that in stainless steels 347 and 420.This study can provide some reference for the structural design of high-temperature molten-salt pumps.