开孔折流板对列管式换热器传热性能的影响研究

针对由传统弓形折流板结构带来的壳程流动死区,从而引起的流动阻力大、传热效率低等问题,本文对折流板进行开孔,通过数值模拟的方法研究开孔折流板结构对列管式翅片换热器壳侧流体流动、传热及阻力性能的影响。研究发现,折流板开孔后,壳程流动死区明显减小,壳程传热系数及压降同比开孔前降低了;综合换热性能同比开孔前提升了。壳程压降随开孔率及板间距的增大而减小,壳程努塞尔数Nu随板间距的增大逐渐增大。从综合换热性能及场协同的角度分析发现,开孔率x=0.229、折流板间距H=85 mm的列管式换热器综合传热性能最佳。

Study on the Effect of Holed-baffles on the Heat Transfer Performance of Tubular Heat Exchanger

The shell-side flow dead zone caused by the traditional bow baffle structure has not been effectively solved,resulting in high flow resistance and low heat transfer efficiency.In order to solve the above problems,the holed-baffles are used,and the effects of the structure of holed-baffles on the fluid flow,heat transfer and resistance performance of the shell side of tubular fin heat exchanger are studied by numerical simulation.It is found that the dead zone of shell-side flow decreases significantly after baffle opening,and the heat transfer coefficient and pressure drop of shell-side decrease respectively compared with those before baffle opening.The comprehensive heat transfer performance of tubular heat exchangers with opening increased respectively.The pressure drop of shell side of tubular heat exchanger decreases with the increase of hole ratio and plate spacing,while Nusselt number of shell side increases with the increase of plate spacing.From the point of view of comprehensive heat transfer performance and field coordination,it is found that the tubular heat exchanger with opening ratio of 0.229 and baffle spacing of 85 mm has the best comprehensive heat transfer performance.