流体诱导U形换热管束振动特性数值研究

Numerical Study on Vibration Characteristics of Flow Induced of U-Tubes

针对流体诱导振动引起换热器失效问题,课题组在近真实流场下,对多跨、多管束、带间隙支撑的U形管换热器在受到横向流体冲击时的振动特性进行了研究。研究对象是根据GB/T 151-2014《热交换器》设计的3种不同管芯的U形管换热器,管束排列方式为正三角形,中间等间距分布2块圆形折流板。用数值模拟的方法研究了靠近流体冲击出入口管束的振动特性,不同管排数对中心管振动的影响,以及外排管束对内排管束振动的影响。结果表明:U形管换热器进出口处管束在流体横向冲刷作用下振动剧烈,其加速度振幅随流速的增加而增大;随着外层管排数量增加其对中心管振动的抑制作用越明显;外层管排对其相邻的内排管束振动有加强作用。研究可为研究U形换热管振动机理与防振设计提供参考。

For the heat exchanger failure caused by fluid induced vibration,the vibration characteristics of U-tubes subjected to the cross flow was studied.Research object was the heat exchanger with the multi-span,multi-tube bundle and clearance support in approximate real flow field.Three kinds of heat exchanger U-tubes were designed with different tubes arrayed respectively according to GB/T 151-2014.Tubes were arrayed in equilateral triangle with two circular type baffles equipped at equal distance in the middle.The vibration characteristics of the tube bundles near the exit and inlet,the influence of different tube rows on the vibration of the central tube and the influence of outer row tube bundles on the vibration of inner tube bundles were studied.The result shows that the tube bundles near the exit and inlet vibrate severely when subjected to the cross flow,and the acceleration amplitude increases with the increase of the flow rate.As the number of outer tube bundle rows increases,the suppression of the vibration of the central tube is more obvious.The outer tube row has a reinforcing effect on the vibration of the adjacent inner tube bundle.This paper can provide reference for studying the vibration mechanism and anti-vibration design of heat exchange U-tubes.