折流板对改进型平面弹性管束换热器传热特性的影响

Effect of baffles on heat transfer characteristics of improved plane elastic tube bundle heat exchanger

基于传统平面弹性管束(plane elastic tube bundle,PETB)换热器,通过进行结构改进,提出了一种改进型PETB换热器。研究了折流板结构参数(高度和弧度)对改进型PETB换热器传热特性的影响。结果表明:随着折流板高度增加,内部传热元件的振动强度减小,传热元件的振动强化传热性能和换热器的综合传热性能均提高。当比例因子由0.70增加到0.80时,监测点的振动幅值降低7%以上;振动条件下传热元件的平均努赛尔数提高5.50%,换热器的综合传热性能评价指标(performance evaluation criteria,PEC)提高1.42%。折流板弧度的变化影响传热元件的振动强度和传热性能,当折流板弧度为10°时,监测点的振动最剧烈,传热元件的振动强化传性能和换热器的综合传热性能均最高。与弧度为0°和20°相较,监测点的振幅最大分别提高6.27%和6.63%;振动条件下传热元件的平均努赛尔数分别提高2.91%和2.78%,换热器的综合传热性能评价指标PEC分别提高0.83%和3.23%。

An improved plane elastic tube bundle(PETB) heat exchanger was proposed.The effect of baffle structural parameters,including height and radian,on heat transfer performance of improved PETB heat exchanger was studied.The results show that with the increase of baffle height,the vibration intensity of internal heat transfer components decreases,the vibration reinforced heat transfer property of heat transfer components and the overall heat transfer property of heat exchanger improve.When the scale factor increases from 0.70 to 0.80,the vibration amplitude of the monitoring point decreases by over 7%.The average Nusselt number of components is raised by 5.50% and the performance evaluation criteria(PEC) is raised by 1.42% under vibration condition.The variation of the radian of the baffle plate affects the vibration intensity and heat transfer performance of the heat transfer element.When the radian of the baffle is 10°,the vibration of the monitoring point is the most intense,the reinforced heat transfer property of components and the overall heat transfer property of heat exchanger are the greatest.Compared with radian 0° and 20°,the amplitude of monitoring point increases by 6.27% and 6.63%,respectively.The average Nusselt number of components under vibration condition increases by 2.91% and 2.78% respectively,and the PEC increases by 0.83% and 3.23% respectively.