固定床错流流动和传热耦合的数值模拟

引入对流项和黏性项的流动模型和传热模型耦合,对内置传热管构件的固定床错流传热进行了研究,获得了床层温度分布,并与文献实验数据进行比较:计算值与文献实验值基本一致,表明模型能正确描述床层的温度分布。然后在不同的三角形和正方形排列方式情况下,研究了床层内在多圆管管间及周边的温度分布,结果表明:错流传热与流体流动方向密切相关,床层被加热的区域在加热管二侧,管壁附近和床层加热管前方,这些区域出现了较宽的被加热区;采用三角形排列方式,与采用正方形排列方式相比,强化了床层内的对流传热,使得床层内温度分布更趋于均匀。

Numerical simulation of coupling of heat transfer with cross flow in fixed bed

In consideration of convection term and diffusion term,the cross-flow heat transfer in fixed bed with embedded cylinder was discussed in two-dimensional model by the coupling of heat transfer with fluid flow.The numerical solutions were compared with the experimental data in the open literature.The favorable comparison of the experimental data with the computed results indicates that the mathematical model developed here is effective to describe the temperature distribution of the fixed bed.Taking into account the different arrangement modes of more crossed tubes,the temperature distribution around the tube was studied.The result shows that the process of cross-flow heat transfer has a close connection with the fluid flow direction;the zone affected by heat tubes is mainly in front of the tube and both sides,especially in front of the tube,the heated zone is very wide.Tube arrangement in triangle offers better heat transfer than tube arrangement in square.