真实流场中换热管流体诱导振动特性研究  

Characteristic of fluid induced vibration of tube bundle with realistic flow field

作　　者：施卿海[1] 苏文献[1] 王宏光[1] SHI Qing-hai;SU Wen-xian;WANG Hong-guang(School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《振动工程学报》2019年第2期278-287,共10页Journal of Vibration Engineering

摘　　要：工程用换热器中由于折流板的存在,壳程流体折返冲刷换热管,换热器内流场十分复杂。采用实验和数值模拟相结合的方法对正方形排列节径比为1.25的换热管束在真实流场中的流体诱导振动问题进行分析研究。结果表明:流体折返冲刷换热管,复杂的流体力分布抑制了换热管与漩涡脱落的共振效应。管束边缘换热管受到流体力作用,会极大地偏离原始位置,在新的平衡位置做小振幅振动,振动振幅受管束间隙流速影响较小。管束边缘换热管较大的刚体位移和小幅的高频振动,会加剧换热管与折流板间的切割效应。该研究结果可以作为大型换热器局部流体诱导振动分析与标准完善的依据。With the large-scale and high-efficiency trend of the shell and tube heat exchanger, fluid induced vibration of the tube bundle has aroused more and more scholars′ attention. Heat exchange tube is repeatedly washed by shell media because of the baffles, especially for the segmental baffle heat exchangers where the leakage flow passages account for a large proportion and the dead space is large. The flow field inside the heat exchanger is very complicated. However, domestic and foreign researches on fluid induced vibration in heat exchange tubes with realistic flow field are still limited. In this paper, a method combined with experiment and numerical simulation is used to analyze the fluid induced vibration of a heat-exchange bundle with a square pitch ratio of 1.25. In the experimental installation, both ends of the heat exchange tubes are fixedly connected with the tube plates, and the middle of the tubes are simply supported by two baffles. The experimental device simulates the shell side fluid repeatedly entering the heat exchanger, and the part of the heat-exchange tubes washed by the shell medium. The results show that the more complicated distribution of fluid force suppresses the resonance effect between heat exchange tubes and vortex shedding. The outside tubes of the bundle greatly deviate from the original position due to fluid forces, and have small amplitude vibration at the new equilibrium position where the vibration amplitude is less influenced by the tube gap velocity. Their larger displacement and high frequency vibration can exacerbate the cutting effect between the tubes and the baffles, and these dangers cannot be ignored. The results of this paper can be used as a basis for the analysis of local fluid induced vibration and improving the standard of large heat exchangers.

关 键 词：流体诱导振动 换热管 折流板 折返流场 局部冲刷 

分 类 号：TB123[理学—工程力学] TK172[理学—力学]