折流板切口方向对管壳式换热器传热性能影响

为了研究单弓形折流板的切口方向对管壳式换热器传热与流动性能的影响,文中通过建立3个不同折流板切口方向的管壳式换热器简化实体模型,运用CFD软件Fluent对管壳式换热器壳程传热与流动状态进行了三维数值模拟。以水为壳程流体介质,在不断改变壳程进口流速,使得壳程进口雷诺数Re在10 000到70 000范围内变化时,得到了不同状态下的壳程流场与温度场。根据数值模拟结果,以总传热系数α,壳程总压降Δp以及单位压降下的传热系数α/Δp作为综合衡量标准,分析不同折流板切口方向时的管壳式换热器壳程流场与温度场。数值模拟分析结果表明:折流板为垂直切口方向时,管壳式换热器总传热系数最大,压降最小,综合性能最好,另外2种折流板切口方向的管壳式换热器综合性能差不多。

Effect of baffle orientation on heat transfer performance of shell-and-tube heat exchangers

In order to study the effect of baffle orientation on the heat transfer and pressure drop in a shell-and-tube heat exchanger,three simplified physical models of shell-and-tube heat exchanger with different baffle orientation were built for three dimensional numerical simulation.The shellside turbulent flow and heat transfer characteristics of shell-and-tube heat exchanger were studied by using computational fluid dynamics(CFD) software Fluent.With water as fluid medium,the pressure fields and temperature fields of shellside at different shellside flow rates were gained by constantly changing the shellside inlet flow rates to keep Reynolds numbers ranging from 10 000 to 7 000.According to the numerical simulation results,the performance of three shell and tube heat exchanger models was compared and assessed by using heat transfer coefficient α,pressure drop Δp,and the comprehensive performance factor α/Δp.The results show that when the baffle orientation is in vertical,the total heat transfer coefficient of shell-and-tube heat exchanger is the maximum,pressure drop is the smallest and the comprehensive performance is the best.Moreover,the vertical baffle orientation seems to be more advantageous than two others.