翅片结构对开缝翅片管空冷器性能的影响

Effects of Fin Structure on Heat Transfer and Resistance Characteristics of Super Slit Finned Tube Air Cooler

摘要: 基于双向开缝翅片4排管空冷器的原始模型，建立了涡发生器高度分别为0.2_f、0.4_f、0.6_f和0.8_f的4种半球突开缝翅片管空冷器的物理模型，运用三维数值模拟方法对不同涡发生器高度的空冷器的Nu数、Eu数和等压降下的综合性能指标进行了研究，并运用场协同原理对半球突开缝翅片管空冷器的换热性能进行了分析。结果表明：在相同雷诺数下，空冷器的努塞尔数和欧拉数均随着涡发生器高度的增加而增大。与未布置涡发生器的空冷器相比，布置高度为0.8_f涡发生器的空冷器的努塞尔数提升了4.16%~4.33%，欧拉数提升了3.16%~4.54%，等压降下的综合性能指标提升了2.06%~2.56%。半球突涡发生器能够改善速度场与温度场的协同性从而减小协同角并达到强化传热的效果。研究成果可为开缝翅片管空冷器传热和阻力性能的进一步优化提供参考。

Abstract: Based on the original model of the bidirectional slit finned 4-row tube air cooler, four physical models of semi-dimpled slit finned tube air cooler with different vortex generator heights (0.2_f, 0.4_f, 0.6_f and 0.8_f) were established. The Nusselt number, Euler number and the comprehensive performance index were investigated by employing 3-D numerical simulation method and the field synergy principle was used to analyze the thermal performance of semi-dimpled slit finned tube air cooler. The results show that under the same Reynolds number, both the Nusselt number and Euler number of the air cooler increase with the increase of the height of the vortex generator. Compared with the air cooler without the vortex generator, the Nusselt number of the air cooler with the 0.8_f vortex generator is increased by 4.16%~4.33%, the Euler number is increased by 3.16%~4.54%, and the comprehensive performance index is increased by 2.06%~2.56% with the same Reynolds number. The semi-dimpled vortex generator can improve the synergy between the velocity field and the temperature field, thereby reducing the synergy angle and achieving the effect of enhancing heat transfer. The research results can provide reference for the further optimization of the heat transfer and resistance performance of the slit fin tube air cooler.