膜片管束通道传热性能的数值研究

Numerical Study of Convection Heat Transfer in Membrane Channel

以膜片管束通道为研究对象,通过数值模拟分别对通道的入口段和充分发展段建立非稳态数学模型。在不同Re下的通道入口段中不同几何周期的相应截面上设置无量纲速度和无量纲温度的监测点,分析了入口段的换热特性,并且重点探讨了流动与换热进入周期性充分发展段后,改变管束排列方式对换热Nu的影响。结果表明:Re不同时,流动和换热进入充分发展需要经过的几何周期数也不同;进入充分发展段后,Nu随着管间距的减小而逐渐增加,而且对于大间距排列管束,改变圆管竖直方向间距对Nu的产生的影响更显著。

In order to study the convection heat transfer in membrane channel numerically,the unsteady numerical models of the entrance region and the fully developed region are established.The sample points are set on the corresponding geometric periods in the entrance region to analyse the heat transfer characteristics of the entrance region.And the paper mainly discusses the effect of the tube spacing on Nu in the fully developed region.The results showed that,the geometric period of flow and heat transfer entering the full development region is affected by Re;Nu increases gradually with the decrease of tube spacing in the fully developed region,and for the sparse array tube bundles,the effect of changing the vertical spacing on Nu is more significant.