平直-波纹翅片扁平管外空气流动与换热特性的数值研究

Numerical Simulation for the Performance of Flow and Heat Transfer on Air-side of Plain-wavy Fin Flat Tube

利用Fluent软件,完成了平直翅片、波纹翅片和6种不同结构的平直-波纹复合翅片扁平管空气侧流动和换热的三维数值模拟研究。对温度场、速度场、表面平均传热系数、进出口压降、综合换热性能因子进行了分析对比,揭示了进口风速(1m/s^5m/s)、复合翅片中波纹翅片所占比例以及所处位置对翅片表面平均传热系数、通道进出口压降和综合换热性能因子的影响。结果表明,复合翅片中波纹翅片所占比例是影响进出口压降的主要因素;复合翅片中波纹翅片所处位置对换热性能的影响显著,但对进出口压降的影响很小;平直-波纹复合翅片可以提高蛇形翅片扁平管换热器的综合性能;当迎面风速大于2.6m/s时,B15P5型复合翅片的综合换热性能最优。

Three-dimensional numerical simulations of air flow and heat transfer outside flat tubes with plain fins,wavy fins and 6 different structures of plain-wavy fins were carried out by using Fluent.The temperature and velocity fields,the surface average heat transfer coefficient,pressure drop and comprehensive heat transfer performance factor were compared and analyzed.The influence of air inlet velocity(1 m/s^5 m/s),the proportion and location of the wavy fin in the combined fin on the surface average heat transfer coefficient,the pressure drop and the comprehensive heat transfer performance factor was revealed.The result shows that the proportion of the wavy fin in the combined fin is the main factor affecting the pressure drop,and the position of the wavy fin in the combined fin has an obvious influence on the heat transfer performance,but it has little effect on the pressure drop.The plain-wavy fin can improve the comprehensive performance of the snake finned flat tube heat exchanger.When the air inlet velocity is greater than 2.6 m/s,the comprehensive heat transfer performance of B15 P5 combined fin is the best.