列管式换热器中管程介质流动均匀性数值模拟与优化

Numerical Simulation and Optimization for Gas Flow Distribution in Tube Side of Tube Heat Exchanger

在双管程烟-水介质的列管式换热器中,针对烟气在管程中流量分布不均匀对换热效果的不利影响,利用FLUENT软件对管程结构进行模拟与优化。考虑折返通道高度h、两管程间距L、换热管列数r、管内径d和管节距S 5个主要特征尺寸对流动均匀性的影响,采用正交试验方法进行数值模拟试验。通过极差和方差分析,得出影响烟气流动均匀性的显著因素是d,其次是r和h,而不显著因素是L和S。在模拟参数范围内,得到管程结构的最优组合参数:h为60mm,L为20 mm,r为4,d为7 mm,S为11.6 mm[1.45(d+1)]。优化后的各管程中流动均匀性明显得到改善。

A numerical simulation based on FLUENT software was carried out for airflow distribution uniformity of tube side, which in the tubular heat exchanger with double tube side of smoke-water medium. The influence analysis on the maldistribution under different conditions of split range channels height, distance of both tube side, tube columns number, internal diameter of tube and tube spacing were considered. The orthogonal design theory was used to design numerical experiments. The simulation results show that the internal diameters of tube have an important influence on the maldistribution, and the next important factors are the tube columns number and split range channels height, but the unsignificant factors are the distance of two tube side and tube spacing by the range analysis and variance analysis. The optimal combination structure of the tube side within the scope of the simulation is that, the split range channels height is 60 mm. The distance of both tube side is 20 mm. The tube columns number is 4. The internal diameter of tube is 7 mm, and the tube spacing is 11.6 mm. The flow uniformity was obviously improved in the tube side after optimization.