带非均质盐膜多层异质结构吸热管超声导波传播特性仿真研究  

Simulation of ultrasonic guided wave propagation characteristics in multilayer heterogeneous absorber tubes with non-homogeneous salt films

作　　者：倪心怡 徐晓萌 曹逻炜 李乐 姚雪佳 贾国栋[2] NI Xinyi;XU Xiaomeng;CAO Luowei;LI Le;YAO Xuejia;JIA Guodong(China Jiliang University,Hangzhou 310018,Zhejiang,China;China Special Equipment Inspection&Research Institute,Beijing 100029,China)

机构地区：[1]中国计量大学,浙江杭州310018 [2]中国特种设备检测研究院,北京100029

出　　处：《储能科学与技术》2025年第3期1168-1176,共9页Energy Storage Science and Technology

基　　金：国家重点研发计划项目(2023YFF0614902)。

摘　　要：在塔式太阳能光热储能发电系统中,吸热管长期处于高温、强辐射及熔盐流体侵蚀等极端工况,其内壁易形成复杂的非均质盐膜结构,这种盐膜与涂层及管道本体共同构成的多层异质结构显著影响超声导波的传播特性和回波特征,增加了检测和分析的难度。为解决多层异质结构管道中超声导波传播特性分析的难题,本工作系统探究了非均质盐膜的生成机理及其影响因素,获取了盐膜的分布特性和尺度特征,并提出了一种基于随机过程和时间序列模型的盐膜表面生成及仿真方法。利用有限元软件COMSOL,构建了包含吸热管基体、涂层及盐膜的多层异质结构模型,并模拟了不同粗糙度盐膜对超声导波信号特征及其传播特性的影响。研究结果表明,盐膜的存在显著衰减了回波信号幅值,降低了传播速度,并引发了超声导波的模态转换;随着盐膜粗糙度的增加,回波能量呈非线性增大趋势,且模态转换波形的复杂性显著增加。本工作研究填补了多层异质结构管道声场仿真研究的空白,为超声导波检测吸热管缺陷提供了理论依据,同时为塔式光热系统的安全评估与维护提供了有力的技术支持。In tower-type solar thermal energy storage and power generation systems,absorber tubes operate under extreme conditions,including high temperatures,intense radiation,and molten salt fluid erosion.Over time,these conditions result in the formation of complex heterogeneous salt films on the inner tube walls.The salt film,combined with the coating and the tube substrate,creates a multi-layered heterogeneous structure that significantly affects the propagation characteristics and echo signals of ultrasonic guided waves.Consequently,defect detection and analysis are rendered complicated.Thus,this study systematically investigates the formation mechanisms and influencing factors of heterogeneous salt films,characterizing their distribution and scale properties.Further,a novel simulation method for salt film surfaces,based on stochastic processes and time series models,is proposed.Employing the finite element software COMSOL,a multi-layered heterogeneous model incorporating the tube substrate,coating,and salt film is developed to simulate the effects of salt films under varying roughness levels on ultrasonic guided wave signal characteristics and propagation behavior.The presence of salt films is found to significantly attenuate echo signal amplitude,reduce wave propagation velocity,and induce mode conversion in ultrasonic guided waves.Moreover,with increase in the salt film roughness,the echo energy exhibits a non-linear growth trend,and the complexity of modeconverted waveforms intensifies.Thus,the results highlight the importance of this study in terms of bridging a critical gap in the simulation of acoustic fields in multi-layered heterogeneous pipelines,thereby providing a theoretical foundation for ultrasonic guided wave-based defect detection in absorber tubes.Furthermore,this study offers robust technical support for the safety assessment and maintenance of tower-type solar thermal systems.

关 键 词：塔式太阳能吸热管 超声导波 多层异质结构 非均质盐膜 数值仿真 

分 类 号：TB559[理学—物理]